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Sample records for intermittent negative pressure

  1. Evaluation of continuous and intermittent myocardial topical negative pressure

    DEFF Research Database (Denmark)

    Lindstedt, Sandra; Malmsjö, Malin; Gesslein, Bodil

    2008-01-01

    Topical negative pressure, commonly used in wound therapy, has been shown to increase blood flow and stimulate angiogenesis in subcutaneous tissue and skeletal muscle. In wound therapy, intermittent negative pressure is often preferred to continuous negative pressure as tissue exposed to intermit...

  2. Intermittent negative pressure wound therapy with instillation for the treatment of persistent periprosthetic hip infections: a report of two cases

    Directory of Open Access Journals (Sweden)

    Söylemez MS

    2016-02-01

    Full Text Available Mehmet Salih Söylemez,1 Korhan Özkan,2 Bülent Kılıç,3 Samet Erinç41Department of Orthopaedics and Traumatology, Bingöl State Hospital, Bingöl, 2Department of Orthopaedics and Traumatology, Faculty of Medicine, Medeniyet University, Istanbul, 3Department of Orthopaedics and Traumatology, Orthopaedic Surgery Clinic, Istanbul Gelişim University, Tekirdağ, 4Department of Orthopaedics and Traumatology, Istanbul Medeniyet University, Göztepe Training and Research Hospital, Istanbul, TurkeyAbstract: Intermittent negative pressure wound therapy with instillation (NPWTi is starting to be used successfully to treat early periprosthetic infections of endoprostheses. However, few articles have reported the outcome of treatment with intermittent NPWTi for late persistent periprosthetic infections of the hip. In this study, we report two cases who underwent several rounds of radical wound debridement for the treatment of a late persistent periprosthetic infection of the hip. Intermittent NPWTi was used in both cases. Patients were treated successfully and there was no recurrence after 3 and 1 years of follow-up, respectively.Keywords: negative pressure, vacuum-assisted, periprosthetic infection, hip

  3. The Effects of Variable, Intermittent, and Continuous Negative Pressure Wound Therapy, Using Foam or Gauze, on Wound Contraction, Granulation Tissue Formation, and Ingrowth Into the Wound Filler

    Science.gov (United States)

    Malmsjö, Malin; Gustafsson, Lotta; Lindstedt, Sandra; Gesslein, Bodil; Ingemansson, Richard

    2012-01-01

    Objective: Negative pressure wound therapy (NPWT) is commonly used in the continuous mode. Intermittent pressure therapy (IPT) results in faster wound healing, but it often causes pain. Variable pressure therapy (VPT) has therefore been introduced to provide a smooth transition between 2 different pressure environments, thereby maintaining the negative pressure environment throughout the therapy. The aim of the present study was to examine the effects of IPT and VPT on granulation tissue formation. Method: A peripheral wound in a porcine model was treated for 72 hours with continuous NPWT (-80 mm Hg), IPT (0 to -80 mm Hg), or VPT (-10 to -80 mm Hg), using foam or gauze as wound filler. Wound contraction and force to remove the wound filler were measured. Biopsies from the wound bed were examined histologically for granulation tissue formation. Results: Intermittent pressure therapy and VPT produced similar results. Wound contraction was more pronounced following IPT and VPT than continuous NPWT. Intermittent pressure therapy and VPT resulted in the formation of more granulation tissue than continuous NPWT. Leukocyte infiltration and tissue disorganization were more prominent after IPT and VPT than after continuous NPWT. Granulation tissue grew into foam but not into gauze, regardless of the mode of negative pressure application, and less force was needed to remove gauze than foam. Conclusions: Wound contraction and granulation tissue formation is more pronounced following IPT and VPT than continuous NPWT. Granulation tissue grows into foam but not into gauze. The choice of negative pressure mode and wound filler is crucial in clinical practice to optimize healing while minimizing pain. PMID:22292101

  4. Intermittent negative pressure applied to the lower limb increases foot macrocirculatory and microcirculatory blood flow pulsatility in people with spinal cord injury.

    Science.gov (United States)

    Sundby, Øyvind Heiberg; Høiseth, Lars Øivind; Irgens, Ingebjørg; Mathiesen, Iacob; Lundgaard, Eivind; Haugland, Hanne; Weedon-Fekjær, Harald; Sundhagen, Jon O; Sanbæk, Gunnar; Hisdal, Jonny

    2018-04-01

    Experimental prestudy and poststudy. Examine the acute effects of intermittent negative pressure (INP) applied to the lower limb on foot circulation in people with spinal cord injuries (SCIs). Vascular laboratory, Oslo University Hospital. Twenty-four people with SCI (median age 59 years, range 29-74) were exposed to lower leg INP (-40 mm Hg) using an air-tight pressure chamber connected to an INP generator. The contralateral leg was placed outside the pressure chamber. We continuously measured arterial blood flow velocity (ultrasound Doppler), skin blood flow (laser Doppler), skin temperature of the dorsum of the foot, heart rate (ECG) and systemic blood pressure (Finometer) during 5-min baseline (atmospheric pressure), followed by 10-min INP (alternating 10 s -40 mm Hg and 7 s atmospheric pressure), and 5-min post-INP (atmospheric pressure). Skin blood flow was measured on the foot placed outside the pressure chamber. A mixed effects regression model was applied to estimate the effect of INP on blood flow. To quantify flow fluctuations, we calculated cumulative up-and-down changes in arterial blood flow velocity per minute. Flow fluctuations increased during INP compared to baseline [32.3 cm/s/min (95% CI 26.9 to 37.7) vs. 15.2 cm/s/min (95% CI 9.8 to 20.6), P < 0.001]. Peak blood flow velocity and skin blood flow was reached 2-3 s after the onset of negative pressure and increased 33% (95% CI 16 to 46, P < 0.001) and 11% (95% CI -4.1 to 60, P = 0.14) above baseline, respectively. INP induced increased foot arterial blood flow fluctuations compared to baseline. The Norwegian Research Council provided funding to Otivio (grant: 241589).

  5. [Effect of intermittent negative pressure on matrix metalloproteinase 9 and transforming growth factor β of tendon-bone interface and joint fluid after reconstruction of anterior cruciate ligament in rabbits].

    Science.gov (United States)

    Sun, Z M; Dong, X H; Sun, Z J; Chang, Y H; Wu, X Y; Yi, Z; Ling, M

    2017-12-05

    Objective: To study the effect of intermittent negative pressure on matrix metalloproteinase 9 (MMP)-9 and transforming growth factor β of tendon-bone interface and joint fluid after reconstruction of anterior cruciate ligament in rabbits. Methods: A total of twenty-four New Zealand white rabbits were randomly selected hind leg of negative group, contralateral hind leg as control.Reconstruction of the anterior cruciate ligament was done by autogenous semitendinosus of rabbit.Joint of the negative pressure side placed drainage tube connecting the micro-negative pressure aspirator, and maintained an intermittent, low-intensity negative pressure.Control side placed ordinary drainage tube.Drainage tube of both sides was pulled out at the same time after 5 days.After 6 weeks, joint fluid and femur-ligament-tibia complex were obtained for study of expression of MMP-9 and TGF-β in joint fluid and tendon-bone interface. Result: Twenty-three rabbits were included in the study because of one rabbit joint infections.Detection of joint fluid showed that MMP-9 content is significantly lower in negative group than that in the control group, and the difference is statistically significant [(8.9±1.3) pg/L vs (12.3±1.8) pg/L ( P =0.002)]. TGF-β content is significantly higher in negative group in joint fluid than that in the control group, and the difference is statistically significant [(19.0±2.2) pg/L vs (15.2±1.4) pg/L ( P =0.000)]. Study of immunohistochemistry in tendon-bone interface found that expression of MMP-9 is lower in negative pressure group than that in the control group, and the difference is statistically significant ( P =0.000). TGF-β expression is significantly higher in negative group in tendon-bone interface than that in the control group, and the difference is statistically significant ( P =0.000). Conclusion: Intermittent negative pressure may reduce content of MMP-9 in joint fluid and expression of MMP-9 in tendon-bone interface, increase content of

  6. [Negative pressure therapy: NPT].

    Science.gov (United States)

    Maillard, H

    2015-01-01

    Negative pressure therapy or treatment (NPT) is used very frequently in hospitals in both surgical and medical departments. NPT consists of maintaining the wound surface at a pressure below ambient atmospheric pressure by means of a specially designed dressing attached to a depressurisation device as well as a system to drain exudate. NPT has been shown to be beneficial in increasing blood flow, thanks to feedback resulting from the decreased oxygen pressure, angiogenesis and reduction of the wound surface area. The French Health Authority (HAS) has issued recommendations for good use in a specific and limited series of applications. NPT may be used in post-traumatic or post-surgical wounds, burns, and in chronic wounds, such as bedsores and ulcers. It is also effective as an adjuvant treatment for infected wounds. In recent years, various different NPT devices have become commercially available. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  7. The effects of intermittent negative pressure on the lower extremities' peripheral circulation and wound healing in four patients with lower limb ischemia and hard-to-heal leg ulcers: a case report.

    Science.gov (United States)

    Sundby, Øyvind H; Høiseth, Lars Ø; Mathiesen, Iacob; Jørgensen, Jørgen J; Sundhagen, Jon O; Hisdal, Jonny

    2016-10-01

    Peripheral circulation is severely compromised in the advanced stages of peripheral arterial disease. Recently, it was shown that the application of -40 mmHg intermittent negative pressure (INP) to the lower leg and foot enhances macro- and microcirculation in healthy volunteers. In this case report, we describe the effects of INP treatment on four patients with lower limb ischemia and hard-to-heal leg and foot ulcers. We hypothesized that INP therapy may have beneficial hemodynamic and clinical effects in the patients. Four patients (age range: 61-79 years) with hard-to-heal leg and foot ulcers (6-24 months) and ankle-brachial pressure indices of ≤0.60 on the affected side were included. They were treated with an 8-week intervention period of -40 mmHg INP (10 sec negative pressure and 7 sec atmospheric pressure) on the lower limbs. A custom-made vacuum chamber was used to apply INP to the affected lower leg and foot for 2 h per day. After 8 weeks of INP therapy, one ulcer healed completely, while the other three ulcers were almost completely healed. These cases suggest that INP may facilitate wound healing. The theoretical foundation is that INP assists wound healing by improving blood flow to the small blood vessels in the affected limb, increasing the flow of oxygen and nutrients to the cells. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  8. Thermodynamics of negative absolute pressures

    International Nuclear Information System (INIS)

    Lukacs, B.; Martinas, K.

    1984-03-01

    The authors show that the possibility of negative absolute pressure can be incorporated into the axiomatic thermodynamics, analogously to the negative absolute temperature. There are examples for such systems (GUT, QCD) processing negative absolute pressure in such domains where it can be expected from thermodynamical considerations. (author)

  9. [APPLICATION OF NEGATIVE PRESSURE THERAPY].

    Science.gov (United States)

    Laginja, S; Marinović, M

    2016-01-01

    Negative pressure therapy is gradually taking an increasingly important role in the treatment of chronic wound healing because of its simple application in hospital or outpatient setting and good comfort with no pain for the patient. Chronic wound healing is accelerated in comparison with other conservative treatments. The level of negative pressure is between 40 and 125 mm Hg below ambient. Direct and indirect effect of the negative pressure therapy helps in wound healing and provides good preparation for definitive surgical management of wounds.

  10. Beneficial effects of intermittent suction and pressure treatment in intermittent claudication

    DEFF Research Database (Denmark)

    Mehlsen, J; Himmelstrup, H; Himmelstrup, Bodil

    1993-01-01

    The present study reports on the effects of a physical treatment modality in patients with intermittent claudication. During this treatment a major part of the skin surface is subjected to intermittent suction and pressure. In a previous, preliminary study the authors found a beneficial effect...... participated in an open trial investigating the possible effects of the treatment on platelet aggregation and fibrinolysis. Pain-free and maximal walking distances were measured on a treadmill, and systolic blood pressure was measured on the upper limb, the ankle, and the first toe bilaterally. The threshold...... for adenosine diphosphate (ADP)-induced platelet aggregation was tested, and the fibrinolytic activity was estimated from the euglobulin clot lysis time. Active treatment resulted in significant improvements in pain-free and maximal walking distances, whereas no changes could be found during placebo...

  11. Incisional Negative Pressure Wound Therapy

    DEFF Research Database (Denmark)

    Hyldig, Nana; Birke-Sorensen, Hanne; Kruse, Marie

    Aim: Postoperative wound complications make many surgical procedures unnecessarily complex, particularly in high-risk patients. Negative Pressure Wound Therapy is well recognized in the management of open wounds. In recent years, it has been introduced as well in the management of closed surgical...... incisions to reduce postoperative wound complications, though the evidence base to support this intervention is limited. The aim of this study was to assess if Negative Pressure Wound Therapy (NPWT) reduces postoperative complications when applied on closed surgical incisions. Method: A systematic review...

  12. Negative-Pressure Pulmonary Edema.

    Science.gov (United States)

    Bhattacharya, Mallar; Kallet, Richard H; Ware, Lorraine B; Matthay, Michael A

    2016-10-01

    Negative-pressure pulmonary edema (NPPE) or postobstructive pulmonary edema is a well-described cause of acute respiratory failure that occurs after intense inspiratory effort against an obstructed airway, usually from upper airway infection, tumor, or laryngospasm. Patients with NPPE generate very negative airway pressures, which augment transvascular fluid filtration and precipitate interstitial and alveolar edema. Pulmonary edema fluid collected from most patients with NPPE has a low protein concentration, suggesting hydrostatic forces as the primary mechanism for the pathogenesis of NPPE. Supportive care should be directed at relieving the upper airway obstruction by endotracheal intubation or cricothyroidotomy, institution of lung-protective positive-pressure ventilation, and diuresis unless the patient is in shock. Resolution of the pulmonary edema is usually rapid, in part because alveolar fluid clearance mechanisms are intact. In this review, we discuss the clinical presentation, pathophysiology, and management of negative-pressure or postobstructive pulmonary edema. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  13. Intermittent pressure decreases human keratinocyte proliferation in vitro.

    Science.gov (United States)

    Nasca, Maria R; Shih, Alan T; West, Dennis P; Martinez, Wanda M; Micali, Giuseppe; Landsman, Adam S

    2007-01-01

    The aim of this study was to investigate the correlation between pressure changes and keratinocyte proliferation by determining whether keratinocytes exposed to altered mechanical pressures would proliferate at different rates compared to control cells not subjected to pressure changes. Tissue culture flasks of human keratinocytes plated at an approximate density of 15,000 cells/cm(2) undergoing an intermittent cyclic pressure of 362 mm Hg at a frequency of 2.28 or 5.16 cycles/min (0.038 or 0.086 Hz) for 8 h were compared to control flasks grown at ambient room pressure. An in-line pressure transducer was used to monitor and adjust pressure within the cell chambers, using a solenoid valve. A thymidine incorporation assay assessed the amount of cell proliferation in each set of experiments. Differences in proliferation between keratinocytes subjected to cyclic pressure changes and control cells were found to be statistically significant (p < 0.05) in 4 out of 5 proliferation assays. Also, a higher frequency of pressure changes consistently generated a reduced proliferation rate compared to that seen in cells exposed to a lower frequency of pressure changes. These data indicate that keratinocytes undergoing intermittent pressure changes exhibit decreased proliferation rates compared to controls. Furthermore, an increased frequency rate seems to have a greater effect on proliferation than low-frequency rate pressure changes, suggesting that the stress caused by frequently changed pressure may play a greater role in reducing keratinocyte proliferation than the actual magnitude of load applied to the cells. Our results support the current treatment protocol of reducing speed and duration of walking on the site of the wound to promote healing of foot ulcers. (c) 2007 S. Karger AG, Basel.

  14. [Influence of intermittently monitoring on endotracheal tube cuff pressure using handheld pressure gauge].

    Science.gov (United States)

    Huang, Ling; Xie, Chen; Zhang, Lifeng; Meng, Liying; Li, Guizheng; Li, Yang; Huang, Bing; Pan, Linghui; Tang, Zhanhong

    2017-01-01

    To discuss the influence of intermittently monitoring on endotracheal tube cuff pressure using handheld pressure gauge, and to provide some reference for the clinical work. The experiment was carried out on the model of the glass tube, which was divided into three parts. Each part of the experiment was divided into normal pressure group and high pressure group according to the different inflation pressure target value. The endotracheal tube cuff pressure was determined intermittently by using the transparent tracheal models which had a static diameter of 2 cm. The target press value of normal pressure group was 32 cmH 2 O (1 cmH 2 O = 0.098 kPa) while that of high pressure group was 40 cmH 2 O. The handheld pressure gauge was connected with the indicated cuff through a tee joint, and the pressure in the cuff in both groups was determined. The pressure loss caused by intermittent measurement of the two groups was compared. By switching the tee joint, the pressure loss through the gauge self-structure and the pressure loss when connecting and disconnecting the indicated cuff were determined to analyze the causes of pressure loss caused by intermittent measurement of pressure gauge. The pressure loss caused by intermittent measurement of high pressure group was significantly higher than that of normal pressure group (cmH 2 O: 15.10±0.43 vs. 10.19±0.45) with statistical significance (t = -24.875, P = 0.000). The pressure loss through the gauge self-structure of high pressure group was also significantly higher than that of normal pressure group (cmH 2 O: 13.91±0.48 vs. 8.77±0.53), which showed a statistics significance (t = -22.854, P = 0.000). The pressure loss when connecting and disconnecting the indicated cuff of the normal pressure and high pressure groups were (1.33±0.49) cmH 2 O and (1.23±0.55) cmH 2 O, respectively, without statistics significance (t = 0.445, P = 0.662). It was figured that the total pressure loss caused by intermittent measurement of the

  15. Incisional Negative Pressure Wound Therapy

    DEFF Research Database (Denmark)

    Hyldig, Nana

    a randomised controlled trial in two tertiary and three teaching hospitals in three regions of Denmark, the Happy Belly Study, investigating the effectiveness of iNPWT in a population of obese women after caesarean section. The Happy Belly Study has demonstrated that prophylactic iNPWT significantly reduced......-risk population of obese women giving birth by caesarean section. The Happy Belly Study is ongoing and thus this thesis presents preliminary results based on data from the first two-thirds of the scheduled study participants. Nonetheless, the results in this thesis are convincing. Accordingly, i......Women with a pre-gestational body mass index (BMI) above 30 kg/m2 giving birth by caesarean section are at high risk of surgical wound infection compared with women with a BMI below 30 kg/m2. Incisional Negative Pressure Wound Therapy (iNPWT) is one strategy to reduce the rate of surgical wound...

  16. Pressure Autoregulation Measurement Techniques in Adult Traumatic Brain Injury, Part I: A Scoping Review of Intermittent/Semi-Intermittent Methods.

    Science.gov (United States)

    Zeiler, Frederick A; Donnelly, Joseph; Calviello, Leanne; Menon, David K; Smielewski, Peter; Czosnyka, Marek

    2017-12-01

    The purpose of this study was to perform a systematic, scoping review of commonly described intermittent/semi-intermittent autoregulation measurement techniques in adult traumatic brain injury (TBI). Nine separate systematic reviews were conducted for each intermittent technique: computed tomographic perfusion (CTP)/Xenon-CT (Xe-CT), positron emission tomography (PET), magnetic resonance imaging (MRI), arteriovenous difference in oxygen (AVDO 2 ) technique, thigh cuff deflation technique (TCDT), transient hyperemic response test (THRT), orthostatic hypotension test (OHT), mean flow index (Mx), and transfer function autoregulation index (TF-ARI). MEDLINE ® , BIOSIS, EMBASE, Global Health, Scopus, Cochrane Library (inception to December 2016), and reference lists of relevant articles were searched. A two tier filter of references was conducted. The total number of articles utilizing each of the nine searched techniques for intermittent/semi-intermittent autoregulation techniques in adult TBI were: CTP/Xe-CT (10), PET (6), MRI (0), AVDO 2 (10), ARI-based TCDT (9), THRT (6), OHT (3), Mx (17), and TF-ARI (6). The premise behind all of the intermittent techniques is manipulation of systemic blood pressure/blood volume via either chemical (such as vasopressors) or mechanical (such as thigh cuffs or carotid compression) means. Exceptionally, Mx and TF-ARI are based on spontaneous fluctuations of cerebral perfusion pressure (CPP) or mean arterial pressure (MAP). The method for assessing the cerebral circulation during these manipulations varies, with both imaging-based techniques and TCD utilized. Despite the limited literature for intermittent/semi-intermittent techniques in adult TBI (minus Mx), it is important to acknowledge the availability of such tests. They have provided fundamental insight into human autoregulatory capacity, leading to the development of continuous and more commonly applied techniques in the intensive care unit (ICU). Numerous methods of

  17. Negative Pressure Wound Therapy in Maxillofacial Applications

    Directory of Open Access Journals (Sweden)

    Adam J. Mellott

    2016-09-01

    Full Text Available Negative pressure wound therapy has greatly advanced the field of wound healing for nearly two decades, by providing a robust surgical adjunct technique for accelerating wound closure in acute and chronic wounds. However, the application of negative pressure wound therapy in maxillofacial applications has been relatively under utilized as a result of the physical articulations and contours of the head and neck that make it challenging to obtain an airtight seal for different negative pressure wound therapy systems. Adapting negative pressure wound therapies for maxillofacial applications could yield significant enhancement of wound closure in maxillofacial applications. The current review summarizes the basic science underlying negative pressure wound therapy, as well as specific maxillofacial procedures that could benefit from negative pressure wound therapy.

  18. Negative interstitial pressure in the peritendinous region during exercise

    DEFF Research Database (Denmark)

    Langberg, Henning; Skovgaard, D; Bülow, J

    1999-01-01

    of these observations, microdialysis was performed in the peritendinous region with a colloid osmotic active substance (Dextran 70, 0.1 g/ml) added to the perfusate with the aim of counteracting the negative tissue pressure. Dialysate volume was found to be fully restored (100 +/- 4%) during exercise. It is concluded......In the present study, tissue pressure in the peritendinous area ventral to the human Achilles tendon was determined. The pressure was measured during rest and intermittent isometric calf muscle exercise at three torques (56, 112, and 168 Nm) 20, 40 and 50 mm proximal to the insertion of the tendon...... in 11 healthy, young individuals. In all experiments a linear significant decrease in pressure was obtained with increasing torque [e.g., at 40 mm: -0.4 +/- 0.3 mmHg (rest) to -135 +/- 12 mmHg (168 Nm)]. No significant differences were obtained among the three areas measured. On the basis...

  19. Negative pressure pulmonary oedema after septoplasty.

    Science.gov (United States)

    García de Hombre, Alina M; Cuffini, Alejandro; Bonadeo, Alejandro

    2013-01-01

    Negative pressure pulmonary oedema (NPPO) is an anaesthetic complication due to acute obstruction of the upper airway, whose main cause is laryngospasm. The pathophysiology involves a strong negative intrapleural pressure during inspiration against a closed glottis, which triggers excessive pressure in the pulmonary microvasculature. Although its diagnosis can be difficult, its recognition helps to minimise morbidity and mortality. This article presents a case of NPPO due to postextubation laryngospasm. Copyright © 2011 Elsevier España, S.L. All rights reserved.

  20. Comprehensive Validation of an Intermittency Transport Model for Transitional Low-Pressure Turbine Flows

    Science.gov (United States)

    Suzen, Y. B.; Huang, P. G.

    2005-01-01

    A transport equation for the intermittency factor is employed to predict transitional flows under the effects of pressure gradients, freestream turbulence intensities, Reynolds number variations, flow separation and reattachment. and unsteady wake-blade interactions representing diverse operating conditions encountered in low-pressure turbines. The intermittent behaviour of the transitional flows is taken into account and incorporated into computations by modifying the eddy viscosity, Mu(sub t), with the intermittency factor, gamma. Turbulent quantities are predicted by using Menter's two-equation turbulence model (SST). The onset location of transition is obtained from correlations based on boundary-layer momentum thickness, acceleration parameter, and turbulence intensity. The intermittency factor is obtained from a transport model which can produce both the experimentally observed streamwise variation of intermittency and a realistic profile in the cross stream direction. The intermittency transport model is tested and validated against several well documented low pressure turbine experiments ranging from flat plate cases to unsteady wake-blade interaction experiments. Overall, good agreement between the experimental data and computational results is obtained illustrating the predicting capabilities of the model and the current intermittency transport modelling approach for transitional flow simulations.

  1. Study of continuous irrigation negative-pressure treatment using an original ulceration model.

    Science.gov (United States)

    Sano, Hitomi; Kajikawa, Akiyoshi; Ueda, Kazuki

    2013-06-01

    A continuous irrigation with intermittent aspiration (CIIA) method has previously been developed in the treatment of infected expander sites. For the purpose of treatment of infected wounds, a new intermittent negative pressure irrigation treatment (INPIT) has been developed that is a combination of CIIA with topical negative-pressure therapy. This study aims to investigate the efficacy of INPIT. The efficacy of irrigation was investigated by changing the conditions including the location and the number of irrigation tubes, flow volume, and the timetable of negative-pressure application using original ulcer models. Although the presence of side holes and increase in the number of tubes or flow volume improved the irrigation efficacy, non-washed-out areas remained. On the other hand, INPIT allowed more uniform and wide area washing even at low flow volume. The results suggest that INPIT is superior to general conventional continuous irrigation treatment in irrigation efficiency.

  2. Active Intracystic Negative Pressure Could Induce Osteogenesis.

    Science.gov (United States)

    Castro-Núñez, Jaime

    2018-02-23

    Based on previous findings, the author introduces the term "sugosteogenesis," a biological phenomenon that occurs by using the Evocyst, a device that exerts active intracystic negative pressure. The term "sugosteogenesis" comes from the Latin word "sugo-," meaning "suck," and Greek words "osteo-," meaning "bone," and genesis, "origin."

  3. Negative pressure wound therapy: clinical utility

    Directory of Open Access Journals (Sweden)

    Sandoz H

    2015-04-01

    Full Text Available Heidi Sandoz Accelerate CIC, Mile End Hospital, London, UK Abstract: Negative pressure wound therapy (NPWT, also known as topical negative pressure therapy, has been increasingly used in health care for the management of a wide variety of wounds over the last 2–3 decades. It is an advanced therapy that can be helpful to accelerate wound healing in both acute and chronic wounds by delivering negative pressure (suction to the wound bed. More recent advancements in the application of NPWT have provided clinicians with wider choices of utilization. There are now devices available that can deliver irrigation to the wound bed, be used for closed surgical incisions, or are disposable and highly portable. Systematic reviews considering NPWT have been published previously. These usually focus on one wound group or device and fail to offer practical clinical guidance due to the scrutiny offered to the evidence via a systematic review process. Here, an overview of the history of NPWT, the varieties of device available, their wide clinical application, and the evidence to support its use are explored in a pragmatic way. Keywords: negative pressure, wound, incision, healing, pain 

  4. 21 CFR 890.1600 - Intermittent pressure measurement system.

    Science.gov (United States)

    2010-04-01

    ... evaluative device intended for medical purposes, such as to measure the actual pressure between the body surface and the supporting media. (b) Classification. Class I (general controls). The device is exempt...

  5. Topical negative pressure therapy: mechanisms and indications.

    Science.gov (United States)

    Banwell, Paul E; Musgrave, Melinda

    2004-06-01

    Topical negative pressure (TNP) therapy has emerged as a high-technology, microprocessor-controlled physical wound-healing modality. Complex effects at the wound-dressing interface following application of a controlled vacuum force have been documented. These include changes on a microscopic, molecular level and on a macroscopic, tissue level: interstitial fluid flow and exudate management, oedema reduction, effects on wound perfusion, protease profiles, growth factor and cytokine expression and cellular activity, all leading to enhanced granulation tissue formation and improved wound-healing parameters. Primary indications for clinical use have been documented and include traumatic wounds, open abdominal wounds, infected sternotomy wounds, wound bed preparation, complex diabetic wounds and skin-graft fixation. Whilst this therapy now forms an essential part of the wound healing armamentarium, extensive clinical trials are recommended to confirm efficacy and delineate its optimum use.

  6. Negative pressure wound therapy and nurse education.

    Science.gov (United States)

    Cray, Amy

    2017-08-10

    there can be serious consequences for patients if negative pressure wound therapy (NPWT) is performed incorrectly and patient safety must be paramount. The existing literature was found to mainly concentrate on the use of the technology from the patient perspective. This article examines the opinions of nurses who apply the therapy. five staff nurses from different areas with differing experience levels were interviewed in a semi-structured manner. The transcribed interviews were coded, sorted into themes and analysed. the themes were: enhancing knowledge and understanding, managing problematic pumps, formalised and interactive training, and efficacy and healing. There was a lack of standardised training provided for the nurses interviewed. Overall the nurses were aware of the basic evidence behind the treatment but would have liked additional support in this area as well as some practical, less pressured training. This complements the existing literature. nurses are expected to learn difficult and highly specialised skills quickly within a busy ward environment, often with no prior training or preparation. As things can go wrong, with the potential for patient harm, it is vital that nurses get these skills right first time, but it is difficult to do this in a practical, fast and cost-effective way. There is scope for future research in the area and perhaps the development of an online training tool to assist nurses in understanding and undertaking a new procedure.

  7. Episodic high irrigation pressure during surgical neuroendoscopy may cause intermittent intracranial circulatory insufficiency.

    Science.gov (United States)

    Fàbregas, N; Valero, R; Carrero, E; Tercero, J; Caral, L; Zavala, E; Ferrer, E

    2001-04-01

    Intermittent high peak pressure values inside the endoscope during neuroendoscopic surgical procedures are associated with postoperative morbidity. Unexpected delay in awakening is the complication most frequently observed by the anesthesiologist as a result of high peak pressure values inside the endoscope. During eight neuroendoscopic procedures the authors continuously monitored cerebral hemodynamic function, using a transcranial doppler (TCD) probe fixed on patients' temporal window. We observed that episodes of high peak pressure values inside the endoscope during neuroendoscopic navigation rinsing periods resulted in changes in the TCD wave profile consistent with "near intracranial circulatory arrestlike" wave. No systemic hemodynamic warning signs accompanied these intermittent episodes of severe decrease in cerebral perfusion pressure. When the rinsing liquid was allowed to escape, the pressure inside the endoscope decreased and the TCD wave immediately returned to its previous value. Neuroendoscopic procedures, although classified as minimally invasive surgery, warrant special monitoring that could alert us to a decrease in cerebral perfusion pressure. Middle cerebral artery TCD recording is a reliable and accurate tool for this purpose.

  8. Renal effects of continuous negative pressure breathing

    Science.gov (United States)

    Kinney, M. J.

    1975-01-01

    Continuous negative pressure breathing (CNPB) was utilized to simulate the thoracic vascular distension of zero G in 11 anesthetized rats. The animals underwent renal clearance and micropuncture renal nephron studies before, during, and after CNPB. Four rats were pretreated with a high salt diet and I-M desoxycorticosterone (DOCA) in excess. None of these rats diuresed with CNPB. In contrast, five of the seven remaining rats increased the fraction of the filtered sodium excreted and their urinary flow rate. Potassium excretion increased. End proximal tubular fluid specimen's TF/P inulin ratios were unchanged. Whole kidney and single nephron glomerular filtration rates fell 10%. CNPB, a mechanism for atrial distension, appears to cause in the rat a decrease in distal tubular sodium and water reabsorption. Exogenous mineral-corticoid prevents the diuresis, saluresis, and kaluresis. The adequacy of other nonatrial volume control mechanisms in regulating renal salt and water conservation in opposition to the studied atrial-renal (Henry-Gauer) reflex of thoracic vascular distension is confirmed.

  9. Negative interstitial pressure in the peritendinous region during exercise

    DEFF Research Database (Denmark)

    Langberg, Henning; Skovgaard, D; Bülow, J

    1999-01-01

    In the present study, tissue pressure in the peritendinous area ventral to the human Achilles tendon was determined. The pressure was measured during rest and intermittent isometric calf muscle exercise at three torques (56, 112, and 168 Nm) 20, 40 and 50 mm proximal to the insertion of the tendon...... in 11 healthy, young individuals. In all experiments a linear significant decrease in pressure was obtained with increasing torque [e.g., at 40 mm: -0.4 +/- 0.3 mmHg (rest) to -135 +/- 12 mmHg (168 Nm)]. No significant differences were obtained among the three areas measured. On the basis...

  10. Predictions of Separated and Transitional Boundary Layers Under Low-Pressure Turbine Airfoil Conditions Using an Intermittency Transport Equation

    Science.gov (United States)

    Suzen, Y. B.; Huang, P. G.; Hultgren, Lennart S.; Ashpis, David E.

    2003-01-01

    A new transport equation for the intermittency factor was proposed to predict separated and transitional boundary layers under low-pressure turbine airfoil conditions. The intermittent behavior of the transitional flows is taken into account and incorporated into computations by modifying the eddy viscosity, t , with the intermittency factor, y. Turbulent quantities are predicted by using Menter s two-equation turbulence model (SST). The intermittency factor is obtained from a transport equation model, which not only can reproduce the experimentally observed streamwise variation of the intermittency in the transition zone, but also can provide a realistic cross-stream variation of the intermittency profile. In this paper, the intermittency model is used to predict a recent separated and transitional boundary layer experiment under low pressure turbine airfoil conditions. The experiment provides detailed measurements of velocity, turbulent kinetic energy and intermittency profiles for a number of Reynolds numbers and freestream turbulent intensity conditions and is suitable for validation purposes. Detailed comparisons of computational results with experimental data are presented and good agreements between the experiments and predictions are obtained.

  11. Synchronized Nasal Intermittent Positive Pressure Ventilation of the Newborn: Technical Issues and Clinical Results.

    Science.gov (United States)

    Moretti, Corrado; Gizzi, Camilla; Montecchia, Francesco; Barbàra, Caterina Silvia; Midulla, Fabio; Sanchez-Luna, Manuel; Papoff, Paola

    2016-01-01

    Although mechanical ventilation via an endotracheal tube has undoubtedly led to improvement in neonatal survival in the last 40 years, the prolonged use of this technique may predispose the infant to development of many possible complications including bronchopulmonary dysplasia. Avoiding mechanical ventilation is thought to be a critical goal, and different modes of noninvasive respiratory support beyond nasal continuous positive airway pressure, such as nasal intermittent positive pressure ventilation and synchronized nasal intermittent positive pressure ventilation, are also available and may reduce intubation rate. Several trials have demonstrated that the newer modes of noninvasive ventilation are more effective than nasal continuous positive airway pressure in reducing extubation failure and may also be more helpful as modes of primary support to treat respiratory distress syndrome after surfactant and for treatment of apnea of prematurity. With synchronized noninvasive ventilation, these benefits are more consistent, and different modes of synchronization have been reported. Although flow-triggering is the most common mode of synchronization, this technique is not reliable for noninvasive ventilation in neonates because it is affected by variable leaks at the mouth and nose. This review discusses the mechanisms of action, benefits and limitations of noninvasive ventilation, describes the different modes of synchronization and analyzes the technical characteristics, properties and clinical results of a flow-sensor expressly developed for synchronized noninvasive ventilation. © 2016 S. Karger AG, Basel.

  12. The effect of intermittent fasting on blood pressure variability in patients with newly diagnosed hypertension or prehypertension.

    Science.gov (United States)

    Erdem, Yunus; Özkan, Gülsüm; Ulusoy, Şükrü; Arıcı, Mustafa; Derici, Ülver; Şengül, Şule; Sindel, Şükrü; Ertürk, Şehsuvar

    2018-01-01

    Intermittent fasting is a phenomenon which can be observed in most humans. The effect of intermittent fasting on blood pressure variability (BPV) has not previously been investigated. The purpose of this study was to assess the effect of fasting on blood pressure (BP) (with office, home, central, and ambulatory blood pressure monitoring [ABPM]) and on BPV. Sixty individuals were included in the study. Office, home, ABPM, and central BP measurements were performed before and during intermittent fasting. Standard deviation and coefficient variation were used for office and home BPV measurement, while the smoothness index was used to calculate ABPM variability. Patients' BP and BPV values before and during intermittent fasting were then compared. Intermittent fasting resulted in a significant decrease in office BP values and ABPM measurements but caused no significant change in home and central BP measurements. Twenty-four hour urinary sodium excretion decreased. Smoothness values obtained from ABPM measurements were low; in other words, BPV was greater. BPV was higher in patients who woke up to eat before sunrise, but BPV was low in patients with high body mass index. Intermittent fasting produced a significant decrease in BP values in terms of office and ABPM measurements in this study but caused no significant change in central BP and home measurements. We also identified an increase in BPV during intermittent fasting, particularly in patients who rose before sunrise. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  13. Intermittent operation of ultra-low pressure ultrafiltration for decentralized drinking water treatment.

    Science.gov (United States)

    Peter-Varbanets, Maryna; Gujer, Willi; Pronk, Wouter

    2012-06-15

    River water was treated by ultrafiltration at a relatively low transmembrane pressure (40 mbar). As observed before, flux stabilization occurred after several days of operation although no back-flushing or cross flow was applied. Interruptions in flux were applied by temporary offset of the transmembrane pressure. After restoration of the transmembrane pressure, the initial flux was higher than the stable flux level, and the flux recovery depended on the standstill time. Furthermore, if a short cross flow was applied after standstill, the flux was restored to an even higher level. In all cases, the flux decreased again during operation to reach finally the same stable level as before standstill. In order to evaluate the influence of intermittent operation as practiced for water treatment on a household level, daily interruptions of flux were applied. An optimum of total daily water production rate was obtained at 21 h of operation and 3 h of standstill per day. A model was developed which can describe the impact of intermittent operation on the flux depending on the duration of the standstill and operating periods. This enables the prediction of production capacity of the system operated intermittently. The flux increase during standstill could be explained by a relaxation and expansion of the biofouling layer, while the higher flux after forward-flushing was caused by this layer being partially sloughed off. Household water treatment with the process presented here will generally be operated on a discontinuous basis. The results show that such operation schemes do not compromise the permeability of the system, but actually lead to higher fluxes after standstill. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Exploiting potency of negative pressure in wound dressing using limited access dressing and suction-assisted dressing

    Directory of Open Access Journals (Sweden)

    Pramod Kumar

    2012-01-01

    Full Text Available Role of negative pressure dressing and moist wound healing are well established in the treatment of both acute and chronic wounds with certain advantages and disadvantages in both the techniques. Both these techniques prevents wound colonization, but the negative pressure dressing method has proved to have a greater potency to remove secretions, prevent wound invasion and eradication established infection. In both these techniques there is no accessibility to wound environment. Limited access dressing (LAD is a moist wound dressing with negative pressure. It provides limited access to the wound through two small ports for both dressers and pathogens. The LAD design has notable advantages like wound isolation that reduces chance of wound colonization and safe disposal of infected materials (important factor to reduce hospital-acquired infections, while avoiding some major disadvantages such as opacity of dressing materials, inaccessible offensive smelling wound environment, and relatively high treatment costs. In LAD a definite intermittent negative pressure regimen is followed. The intermittent negative pressure (cycle of 30 minutes suction and 3 1 / 2 hours rest is effective. Overall, the LAD is a safe and effective alternative to conventional dressing methods. LAD is an excellent research tool for wound healing as frequent/continuous record of wound healing is possible without disturbing the wound healing process. LAD is an effective dressing for limb salvage in cases of acute and chronic complex wounds. Leech effect prevents wound related systematic response syndrome and sepsis. Suction-assisted dressing (SAD is a combination of semiocclusive dressing with negative pressure. It works by removal of fluids by intermittent (like LAD negative pressure and preventing bacterial invasion. SAD is especially advantageous where soakage is less, there is no dead tissue covering the wound (e.g., following skin grafting, superficial skin wounds (e

  15. Fourier and wavelet analyses of intermittent and resonant pressure components in a slot burner

    Science.gov (United States)

    Pagliaroli, Tiziano; Mancinelli, Matteo; Troiani, Guido; Iemma, Umberto; Camussi, Roberto

    2018-01-01

    In laboratory-scale burner it has been observed that the acoustic excitations change the flame topology inducing asymmetry and oscillations. Hence, an acoustic and aeroacoustic study in non reactive condition is of primary importance during the design stage of a new burner in order to avoid the development of standing waves which can force the flame. So wall pressure fluctuations inside and outside of a novel slot burner have been studied experimentally and numerically for a broad range of geometrical parameters and mass flow rates. Wall pressure fluctuations have been measured through cavity-mounted microphones, providing uni- and multi-variate pressure statistics in both the time and frequency domains. Furthermore, since the onset of combustion-driven oscillations is always presaged by intermittent bursts of high amplitude, a wavelet-based conditional sampling procedure was applied to the database in order to detect coherent signatures embedded in the pressure time signals. Since for a particular case the coherent structures identified have a multi-scale signature, a wavelet-based decomposition technique was proposed as well to separate the contribution of the large- and small-scale flow structures to the pressure fluctuation field. As a main outcome of the activity no coupling between standing waves and velocity fluctuations was observed, but only well localized pressure signatures with shape strongly affected by the neighbouring flow physics.

  16. Capillarity Induced Negative Pressure of Water Plugs in Nanochannels

    NARCIS (Netherlands)

    Tas, Niels Roelof; Mela, P.; Kramer, Tobias; Berenschot, Johan W.; van den Berg, Albert

    2003-01-01

    We have found evidence that water plugs in hydrophilic nanochannels can be at significant negative pressure due to tensile capillary forces. The negative pressure of water plugs in nanochannels induces bending of the thin channel capping layer, which results in a visible curvature of the liquid

  17. 21 CFR 868.5935 - External negative pressure ventilator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External negative pressure ventilator. 868.5935 Section 868.5935 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... ventilator. (a) Identification. An external negative pressure ventilator (e.g., iron lung, cuirass) is a...

  18. Pressure Field Around Underwater Negative Streamers

    Czech Academy of Sciences Publication Activity Database

    Hoffer, Petr; Koláček, Karel; Lukeš, Petr; Stelmashuk, Vitaliy

    2015-01-01

    Roč. 43, č. 5 (2015), s. 1787-1792 ISSN 0093-3813 R&D Projects: GA ČR(CZ) GA15-12987S Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100431203 Program:M Institutional support: RVO:61389021 Keywords : Interferometry * plasma generation * pressure measurement * water Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.958, year: 2015

  19. Mask intermittent positive pressure ventilation in chronic hypercapnic respiratory failure due to chronic obstructive pulmonary disease.

    Science.gov (United States)

    Sivasothy, P; Smith, I E; Shneerson, J M

    1998-01-01

    Noninvasive ventilation in chronic obstructive pulmonary disease (COPD) has been shown to improve arterial blood gases but its long-term role has not been established. We retrospectively studied 26 consecutive patients with hypercapnic ventilatory failure due to COPD in whom oxygen therapy caused worsening hypercapnia (defined as a rise in the daytime arterial carbon dioxide tension (Pa,CO2) to >8.0 kPa or nocturnal transcutaneous carbon dioxide tension (Ptc,CO2) to >9 kPa). All were treated with mask ventilation (15 with nasal and 11 face masks) at night and during daytime naps. Additional oxygen therapy was required in 15 patients. The mean annualized death rate was 10.8% with a 1 and 3 yr survival of 92 and 68%, respectively. After 1 yr the median daytime Pa,CO2 had fallen by 1.35 kPa and the arterial oxygen tension (Pa,O2) had risen by 2.4 kPa. In subjects not using additional oxygen the median overnight Sa,O2 rose by 12% and the Ptc,CO2 fell by 2.8 kPa after 1 yr. The haematocrit was significantly less than pretreatment at 6 months and 1 yr. Quality of life in the domain of role limitation by physical health (measured using the SF-36 questionnaire) improved significantly at 6 months. Survival in this selected group with clinically stable airflow obstruction unable to tolerate oxygen therapy and treated with noninvasive mask ventilation is better than historical controls and is comparable to those able to tolerate oxygen therapy. Poor survival was associated with a low forced expiratory volume in one second, a low body mass index and a high nocturnal transcutaneous carbon dioxide tension. No difference in survival was found between those treated with mask intermittent positive pressure ventilation alone or with mask intermittent positive pressure and supplementary oxygen therapy.

  20. Flow-synchronized nasal intermittent positive pressure ventilation in the preterm infant: development of a project

    Directory of Open Access Journals (Sweden)

    Corrado Moretti

    2013-06-01

    Full Text Available This manuscript describes the experience of our team in developing a flow-triggered nasal respiratory support for the neonate and its related clinical applications. Although mechanical ventilation (MV via an endotracheal tube has undoubtedly led to improvement in neonatal survival in the last 40 years, the prolonged use of this technique may predispose the infant to the development of many possible complications, first of all, bronchopulmonary dysplasia (BPD. Avoiding mechanical ventilation is thought to be a critical goal, and different modes of non invasive respiratory support may reduce the intubation rate: nasal continuous positive airway pressure (NCPAP, nasal intermittent positive pressure ventilation (NIPPV and its more advantageous form, synchronized nasal intermittent positive pressure ventilation (SNIPPV. SNIPPV was initially performed by a capsule placed on the baby’s abdomen. To overcome the disadvantages of the abdominal capsule, our team decided to create a flow-sensor that could be interposed between the nasal prongs and the Y piece. Firstly we developed a hot-wire flow-sensor to trigger the ventilator and we showed that flow-SNIPPV can support the inspiratory effort in the post-extubation period more effectively than NCPAP. But, although accurate, the proper functioning of the hot-wire flow-sensor was easily compromised by secretions or moisture, and therefore we started to use as flow-sensor a simpler differential pressure transducer. In a following trial using the new device, we were able to demonstrate that flow-SNIPPV was more effective than conventional NCPAP in decreasing extubation failure in preterm infants who had been ventilated for respiratory distress syndrome (RDS. More recently we used flow-SNIPPV as the primary mode of ventilation, after surfactant replacement, reducing MV need and favorably affecting short-term morbidities of treated premature infants. We also successfully applied SNIPPV to treat apnea of

  1. Using portable negative pressure wound therapy devices in the home care setting

    Directory of Open Access Journals (Sweden)

    Burke JR

    2014-12-01

    Full Text Available Joshua R Burke, Rachael Morley, Mustafa Khanbhai Academic Surgery Unit, Education and Research Centre, University Hospital of South Manchester, Manchester, UK Abstract: Negative pressure wound therapy (NPWT is the continuous or intermittent application of subatmospheric pressure to the surface of a wound that improves the wound environment, accelerates healing, and reduces wound closure time. Since its first documented use, this technology has lent itself to a number of adaptations, most notably, the development of portable devices facilitating treatment in the home care setting. With advancing surgical standards, wound healing is an important rate-limiting factor in early patient discharge and often a major cost of inpatient treatment. The efficacy of NPWT in the home care setting has been investigated through rate of wound closure, time in care, and patient experience. Rate of wound closure is the most appropriate primary end point. Much can be gleaned from patient experience, but the future success of portable NPWT will be measured on time in care and therefore cost effectiveness. However, there is a lack of level 1a evidence demonstrating increased efficacy of portable over inpatient NPWT. The development of portable NPWT is an encouraging innovation in wound care technology, and extending the benefits to the home care setting is both possible and potentially more beneficial. Keywords: portable, negative pressure wound therapy, vacuum-assisted closure, topical negative pressure therapy

  2. Response of Preterm Infants to 2 Noninvasive Ventilatory Support Systems: Nasal CPAP and Nasal Intermittent Positive-Pressure Ventilation.

    Science.gov (United States)

    Silveira, Carmen Salum Thomé; Leonardi, Kamila Maia; Melo, Ana Paula Carvalho Freire; Zaia, José Eduardo; Brunherotti, Marisa Afonso Andrade

    2015-12-01

    Noninvasive ventilation (NIV) in preterm infants is currently applied using intermittent positive pressure (2 positive-pressure levels) or in a conventional manner (one pressure level). However, there are no studies in the literature comparing the chances of failure of these NIV methods. The aim of this study was to evaluate the occurrence of failure of 2 noninvasive ventilatory support systems in preterm neonates over a period of 48 h. A randomized, prospective, clinical study was conducted on 80 newborns (gestational age Ventilatory support failure was observed in 25 (62.5%) newborns treated with nasal CPAP and in 12 (30%) newborns treated with NIPPV, indicating an association between NIV failure and the absence of intermittent positive pressure (odds ratio [OR] 1.22, P newborns receiving nasal CPAP and 12.5% (OR 0.14) receiving NIPPV required invasive mechanical ventilation. Ventilatory support failure was significantly more frequent when nasal CPAP was used. Copyright © 2015 by Daedalus Enterprises.

  3. Inhibitory Effect of Nasal Intermittent Positive Pressure Ventilation on Gastroesophageal Reflux.

    Directory of Open Access Journals (Sweden)

    Danny Cantin

    Full Text Available Non-invasive intermittent positive pressure ventilation can lead to esophageal insufflations and in turn to gastric distension. The fact that the latter induces transient relaxation of the lower esophageal sphincter implies that it may increase gastroesophageal refluxes. We previously reported that nasal Pressure Support Ventilation (nPSV, contrary to nasal Neurally-Adjusted Ventilatory Assist (nNAVA, triggers active inspiratory laryngeal closure. This suggests that esophageal insufflations are more frequent in nPSV than in nNAVA. The objectives of the present study were to test the hypotheses that: i gastroesophageal refluxes are increased during nPSV compared to both control condition and nNAVA; ii esophageal insufflations occur more frequently during nPSV than nNAVA. Polysomnographic recordings and esophageal multichannel intraluminal impedance pHmetry were performed in nine chronically instrumented newborn lambs to study gastroesophageal refluxes, esophageal insufflations, states of alertness, laryngeal closure and respiration. Recordings were repeated without sedation in control condition, nPSV (15/4 cmH2O and nNAVA (~ 15/4 cmH2O. The number of gastroesophageal refluxes recorded over six hours, expressed as median (interquartile range, decreased during both nPSV (1 (0, 3 and nNAVA [1 (0, 3] compared to control condition (5 (3, 10, (p < 0.05. Meanwhile, the esophageal insufflation index did not differ between nPSV (40 (11, 61 h-1 and nNAVA (10 (9, 56 h-1 (p = 0.8. In conclusion, nPSV and nNAVA similarly inhibit gastroesophageal refluxes in healthy newborn lambs at pressures that do not lead to gastric distension. In addition, the occurrence of esophageal insufflations is not significantly different between nPSV and nNAVA. The strong inhibitory effect of nIPPV on gastroesophageal refluxes appears identical to that reported with nasal continuous positive airway pressure.

  4. Negative pressure ventilation enhances acinar perfusion in isolated rat lungs.

    Science.gov (United States)

    Watson, Kal E; Segal, Gilad S; Conhaim, Robert L

    2018-01-01

    We compared acinar perfusion in isolated rat lungs ventilated using positive or negative pressures. The lungs were ventilated with air at transpulmomary pressures of 15/5 cm H 2 O, at 25 breaths/min, and perfused with a hetastarch solution at P pulm art /P LA pressures of 10/0 cm H 2 O. We evaluated overall perfusability from perfusate flows, and from the venous concentrations of 4-µm diameter fluorescent latex particles infused into the pulmonary circulation during perfusion. We measured perfusion distribution from the trapping patterns of those particles within the lung. We infused approximately 9 million red fluorescent particles into each lung, followed 20 min later by an infusion of an equal number of green particles. In positive pressure lungs, 94.7 ± 2.4% of the infused particles remained trapped within the lungs, compared to 86.8 ± 5.6% in negative pressure lungs ( P ≤ 0.05). Perfusate flows averaged 2.5 ± 0.1 mL/min in lungs ventilated with positive pressures, compared to 5.6 ± 01 mL/min in lungs ventilated with negative pressures ( P ≤ 0.05). Particle infusions had little effect on perfusate flows. In confocal images of dried sections of each lung, red and green particles were co-localized in clusters in positive pressure lungs, suggesting that acinar vessels that lacked particles were collapsed by these pressures thereby preventing perfusion through them. Particles were more broadly and uniformly distributed in negative pressure lungs, suggesting that perfusion in these lungs was also more uniformly distributed. Our results suggest that the acinar circulation is organized as a web, and further suggest that portions of this web are collapsed by positive pressure ventilation.

  5. [Nasal synchronized intermittent positive pressure ventilation for the treatment of apnea in preterm infants].

    Science.gov (United States)

    Lin, Xin-Zhu; Zheng, Zhi; Lin, Ya-Yin; Lai, Ji-Dong; Li, Ya-Dan

    2011-10-01

    To compare the efficacy of nasal synchronized intermittent positive pressure ventilation (NSIPPV) and nasal continuous positive airway pressure ventilation (NCPAP) for the treatment of apnea in preterm infants. Eighty preterm infants with apnea from August 2010 to January 2011 were randomly administered with NSIPPV and NCPAP (n=40 each).The blood gas results before and 2 hrs after ventilation, time of using ventilator, therapeutic efficacy and complications were compared between the two groups. There were no significant differences in the blood gas results between the two groups before ventilation. The blood gas results (pH, PO2, PCO2) in the NSIPPV group were better than those in the NCPAP group 2 hrs after ventilation. The time of using ventilator in the NSIPPV group was shorter than that in the NCPAP group (50±9 h vs 91±11 h; P0.05). The proportion of ventilator weaning within 3 days in the NSIPPV group (23/40) was higher than that in the NCPAP group (14/40) (Papnea in preterm infants.

  6. Negative pressure pulmonary edema revisited: Pathophysiology and review of management

    Directory of Open Access Journals (Sweden)

    Balu Bhaskar

    2011-01-01

    Full Text Available Negative pressure pulmonary edema (NPPE is a dangerous and potentially fatal condition with a multifactorial pathogenesis. Frequently, NPPE is a manifestation of upper airway obstruction, the large negative intrathoracic pressure generated by forced inspiration against an obstructed airway is thought to be the principal mechanism involved. This negative pressure leads to an increase in pulmonary vascular volume and pulmonary capillary transmural pressure, creating a risk of disruption of the alveolar-capillary membrane. The early detection of the signs of this syndrome is vital to the treatment and to patient outcome. The purpose of this review is to highlight the available literature on NPPE, while probing the pathophysiological mechanisms relevant in both the development of this condition and that involved in its resolution.

  7. Timer switch to convert suction apparatus for negative pressure wound therapy application

    Directory of Open Access Journals (Sweden)

    Surath Amarnath

    2014-01-01

    Full Text Available Background: Negative pressure wound therapy (NPWT is an established modality in the treatment of chronic wounds, open fractures, and post-operative wound problems. This method has not been widely used due to the high cost of equipment and consumables. This study demonstrates an indigenously developed apparatus which gives comparable results at a fraction of the cost. Readily available materials are used for the air-tight dressing. Materials and Methods: Equipment consists of suction apparatus with adjustable pressure valve set to a pressure 125-150 mmHg. An electronic timer switch with a sequential working time of 5 min and a standby time of 3 min provides the required intermittent negative pressure. Readily available materials such as polyvinyl alcohol sponge, suction drains and steridrapes were used to provide an air tight wound cover. Results: A total of 90 cases underwent 262 NPWT applications from 2009 to 2014. This series, comprised of 30 open fractures, 21 post-operative and 39 chronic wounds. The wound healing rate in our study was comparable to other published studies using NPWT. Conclusion: The addition of electronic timer switch will convert a suction apparatus into NPWT machine, and the results are equally effective compared to more expensive counter parts. The use of indigenous dressing materials reduces the cost significantly.

  8. Negative pressure characteristics of an evaporating meniscus at nanoscale

    Directory of Open Access Journals (Sweden)

    Maroo Shalabh

    2011-01-01

    Full Text Available Abstract This study aims at understanding the characteristics of negative liquid pressures at the nanoscale using molecular dynamics simulation. A nano-meniscus is formed by placing liquid argon on a platinum wall between two nano-channels filled with the same liquid. Evaporation is simulated in the meniscus by increasing the temperature of the platinum wall for two different cases. Non-evaporating films are obtained at the center of the meniscus. The liquid film in the non-evaporating and adjacent regions is found to be under high absolute negative pressures. Cavitation cannot occur in these regions as the capillary height is smaller than the critical cavitation radius. Factors which determine the critical film thickness for rupture are discussed. Thus, high negative liquid pressures can be stable at the nanoscale, and utilized to create passive pumping devices as well as significantly enhance heat transfer rates.

  9. Use of nasal intermittent positive pressure ventilation to avoid intubation in neonates.

    Science.gov (United States)

    Manzar, Shabih; Nair, Arun K; Pai, Mangalore G; Paul, Jose; Manikoth, Prakash; Georage, Mariam; Al-Khusaiby, Saleh M

    2004-10-01

    Nasal intermittent positive pressure ventilation (NIPPV) has widely been used in neonates to prevent extubation failure and apnea. This pilot study was carried out to look at the early use of NIPPV to avoid intubation. The study was carried out over a period of 3 months from August 2003 to October 2003 at the Royal Hospital, Muscat, Sultanate of Oman. The neonates with clinical signs of moderate to severe respiratory distress were given a trial of early NIPPV based on the avoid-intubation protocol. Inclusion, exclusion and failure criteria with general procedure were made clear to all medical and nursing staff and the protocol was posted in the unit for further time to time referral. A total of 16 neonates met the inclusion criteria for early NIPPV trial. Out of these, 13 (81%) had a successful NIPPV. The mean age of entry was 0.95 hours; however, the mean duration of NIPPV was 23 hours. No NIPPV related complications were noted in the study group. We concluded that NIPPV is an appropriate mode of ventilation in neonates requiring respiratory support. The major advantage of NIPPV is the non-invasive mechanics. It is also less expensive and less labor intensive. Further randomized controlled trials with larger sample size are warranted to confirm our findings.

  10. Nasal intermittent positive pressure ventilation (NIPPV) versus nasal continuous positive airway pressure (NCPAP) for apnea of prematurity.

    Science.gov (United States)

    Lemyre, B; Davis, P G; de Paoli, A G

    2002-01-01

    Apnea of prematurity is almost universal in infants who are born before 34 weeks gestation. Previous randomised trials and systematic reviews have found methylxanthines to be effective in preventing apnea of prematurity. However, recent concerns about potential long term side effects of methylxanthines on the neurodevelopment of low birth weight infants have led to an increased interest in alternate methods of treating apnea of prematurity. Nasal continuous positive airway pressure (NCPAP) is a useful method of respiratory support which reduces the incidence of obstructive or mixed apnea. However, apneic infants managed with NCPAP, with or without methylxanthines, sometimes require endotracheal intubation with its attendant morbidity and cost. Nasal intermittent positive pressure ventilation (NIPPV) is a simple, effective mode of respiratory support for older children and adults. It has been used to treat apnea in preterm infants but case reports of gastrointestinal perforations have limited its widespread use. In preterm infants with recurrent apnea, does treatment with NIPPV lead to a greater reduction in apnea and need for intubation and mechanical ventilation, as compared with treatment with NCPAP? Does NIPPV increase the incidence of gastrointestinal complications, i.e. gastric distension leading to cessation of feeds, or perforation? MEDLINE was searched (1966-Oct week 2, 2001). Other sources included the Cochrane Controlled Trials Register (Cochrane Library, Disk Issue 3, 2001) and CINAHL (1982-Sept week 4, 2001). Also used were expert informants, previous reviews including cross-references, and conference and symposia proceedings. All randomised and quasi-randomised trials were included. Participants included unventilated preterm infants experiencing apnea of prematurity. Interventions compared were intermittent positive pressure ventilation administered via the nasal route, either by short nasal prongs or nasopharyngeal tube, and nasal CPAP delivered by

  11. An Affordable Custom-Built Negative Pressure Wound Therapy

    African Journals Online (AJOL)

    Negative pressure wound therapy (NPWT) is a well- established modality for treating complex wounds (1). There are several proposed mechanisms of action of. NPWT (2). The main disadvantage of NPWT is that it is expensive, a drawback that makes this modality of treatment not available in limited-resources countries.

  12. An Affordable Custom-Built Negative Pressure Wound Therapy ...

    African Journals Online (AJOL)

    Negative pressure wound therapy (NPWT) is a wellestablished and effective method for treating complex wounds. However, this modality of treatment may not be available in limited resource countries due to the high cost. We describe a simple and cheap method of NPWT using gauze swabs, a naso-gastric tube, adhesive ...

  13. Experience with the use of negative pressure bolster dressing for ...

    African Journals Online (AJOL)

    Methodology: This was a prospective study of consecutive patients from January 2009 to December 2010, with wounds over uneven and highly mobile anatomic regions that had their skin grafts stabilized using negative pressure wound dressing. Data on patients' age, sex, region of the body that was skin grafted, size of ...

  14. Negative pressure treatment for necrotizing fasciitis after chemotherapy

    Directory of Open Access Journals (Sweden)

    Fraia Melchionda

    2011-12-01

    Full Text Available We describe 2 cases of children with malignant disease who developed severe mucositis with perineal necrotizing fasciitis during severe neutropenia after chemotherapy. Treatment with topical negative pressure therapy with silver foam dressing, together with large spectrum antibiotics, resolved the problem with complete closure of the wound after 30 and 36 days of treatment, respectively.

  15. Controlling a negative loaded hydraulic cylinder using pressure feedback

    DEFF Research Database (Denmark)

    Hansen, M.R.; Andersen, T.O.

    2010-01-01

    This paper is concerned with the inherent oscillatory nature of pressure compensated velocity control of a hydraulic cylinder subjected to a negative load and suspended by means of an over-center valve. Initially, a linearized stability analysis of such a hydraulic circuit is carried out clearly ...... in a nonlinear time domain simulation model validating the linear stability analysis....

  16. The protracted demise of medical technology. The case of intermittent positive pressure breathing.

    Science.gov (United States)

    Duffy, S Q; Farley, D E

    1992-08-01

    In this study, the effects of hospital, staff, and patient characteristics on the rates of use and abandonment of an outmoded medical technology, intermittent positive pressure breathing (IPPB) are analyzed. The study focuses specifically on the use of IPPB to treat inpatients with chronic obstructive pulmonary disease in a national sample of more than 500 community hospitals from 1980 to 1987. Cross-sectionally, hospitals with shorter case-mix-adjusted lengths of stay, private nonprofit or investor-owned hospitals, and hospitals located outside of the north central United States were more likely to abandon IPPB by 1980. Teaching status, location, ownership, volume, and source of payment all appeared to affect rates of IPPB use in 1980. The longitudinal analysis examines both the probability a hospital abandoned IPPB and declines in rates of IPPB use over the study period, conditioned on the availability of IPPB in 1980. The results show that changes in the characteristics of hospitals, patients, and physicians all help to explain variations in the abandonment of IPPB. These findings contrast with previous studies of technological change, which find hospital size to be the most important variable. Size is important in explaining the rate of use in 1980, but it has no effect on the rate of decline in use or abandonment after 1980. In general, the analysis demonstrates that a combination of factors, economic incentives as well as information, contribute to the abandonment of outmoded medical technologies. Given the surprisingly long time periods required for this process to occur, the analysis underscores the need to strengthen financial incentives that encourage appropriate medical decisions and to disseminate information about the efficacy of specific procedures more widely and effectively.

  17. Noninvasive continuous versus intermittent arterial pressure monitoring: evaluation of the vascular unloading technique (CNAP device) in the emergency department.

    Science.gov (United States)

    Wagner, Julia Y; Prantner, Julia S; Meidert, Agnes S; Hapfelmeier, Alexander; Schmid, Roland M; Saugel, Bernd

    2014-01-29

    Monitoring cardiovascular function in acutely ill patients in the emergency department (ED) is of paramount importance. Arterial pressure (AP) is usually monitored using intermittent oscillometric measurements with an upper arm cuff. The vascular unloading technique (VUT) allows continuous noninvasive AP monitoring. In this study, we compare continuous AP measurements obtained by VUT with intermittent oscillometric AP measurements in ED patients. In addition, we aimed to investigate whether continuous noninvasive AP monitoring allows detection of relevant hypotensive episodes that might be missed with intermittent AP monitoring. In a German university hospital, 130 ED patients who required AP monitoring were analyzed in this prospective method comparison study. Continuous AP monitoring was performed using VUT (CNAP technology; CNSystems Medizintechnik AG, Graz, Austria) over a 2-hour period. The oscillometric AP values were recorded simultaneously every 15 minutes for the comparison of both methods. For statistical evaluation, Bland-Altman plots accounting for repeated AP measurements per individual were used. The mean difference (±standard deviation) between AP measurements obtained by VUT and oscillometric AP measurements was -5 mmHg (±22 mmHg) for systolic AP (SAP), -2 mmHg (±15 mmHg) for diastolic AP (DAP), and -6 mmHg (±16 mmHg) for mean AP (MAP), respectively. In the interval between two oscillometric measurements, the VUT device detected hypotensive episodes (≥4 minutes) defined as either SAP system for noninvasive continuous AP measurement shows reasonable agreement with intermittent oscillometric measurements in acutely ill ED patients. Continuous AP monitoring allows immediate recognition of clinically relevant hypotensive episodes, which are missed or only belatedly recognized with intermittent AP measurement.

  18. Rapid Onset Acute Epiglottitis Leading to Negative Pressure Pulmonary Edema

    Directory of Open Access Journals (Sweden)

    V Saraswat

    2007-01-01

    Full Text Available Pulmonary edema is a potentially life-threatening complication of acute airway obstruction. It develops rapidly, without warning, in young healthy individuals. Two forms of post-obstructive pulmonary edema (POPE (also known as negative pressure pulmonary edema, NPPE have been identified. POPE I follows sudden, severe upper airway obstruction. POPE II occurs following surgical relief of chronic upper airway obstruction. Treatment for both is supportive. Full and rapid recovery can be expected with appropriate management. A case report of a middle aged man with acute onset epiglottitis who developed negative pressure pulmonary edema after intubation is presented. The report includes a brief discussion on etiology, clinical features and management dilemma of acute upper airway obstruction.

  19. Proposed application of lower body negative pressure to cardiology

    Science.gov (United States)

    Schmidt, E. V.; Debusk, R. F.; Popp, R. L.

    1975-01-01

    Potential medical applications are presented of lower body negative pressure to the evaluation and treatment of cardiac patients. The essential features of an LBNP unit and the basic cardiovascular physiology of lower body negative pressure (LBNP) testing are described. Some of the results of previous spaceflight experiences and bedrest studies are summarized. The deconditioning effects of weightlessness experienced by orbiting astronauts are compared with the effects of bedrest restrictions prescribed for convalescing cardiac patients. The potential of LBNP for evaluating both pharmacological and physical activity regimens was examined, particularly in relation to post-myocardial infarction and coronary artery bypass patients. Applications of LBNP to the cardiac catheterization laboratory and the out-patient follow-up of cardiac patients are proposed.

  20. Rapid Onset Acute Epiglottitis Leading to Negative Pressure Pulmonary Edema

    OpenAIRE

    V Saraswat; P V Madhu; Suresh S Kumar

    2007-01-01

    Pulmonary edema is a potentially life-threatening complication of acute airway obstruction. It develops rapidly, without warning, in young healthy individuals. Two forms of post-obstructive pulmonary edema (POPE) (also known as negative pressure pulmonary edema, NPPE) have been identified. POPE I follows sudden, severe upper airway obstruction. POPE II occurs following surgical relief of chronic upper airway obstruction. Treatment for both is supportive. Full and rapid recovery can be expecte...

  1. Negative chemical pressure effects induced by Y substitution for Ca ...

    Indian Academy of Sciences (India)

    Negative chemical pressure effects on Ca3Co2O6. Figure 3. Inverse of magnetic susceptibility (χ) as a function of tempera- ture (30–300 K) for Ca3−xYxCo2O6, obtained in a field of 5 kOe. A straight line is drawn through the high-temperature linear region to highlight the x-dependence of θp. The low-temperature data ...

  2. Negative-pressure wound therapy with instillation: international consensus guidelines.

    Science.gov (United States)

    Kim, Paul J; Attinger, Christopher E; Steinberg, John S; Evans, Karen K; Lehner, Burkhard; Willy, Christian; Lavery, Larry; Wolvos, Tom; Orgill, Dennis; Ennis, William; Lantis, John; Gabriel, Allen; Schultz, Gregory

    2013-12-01

    Negative-pressure wound therapy with instillation is increasingly utilized as an adjunct therapy for a wide variety of wounds. Despite its growing popularity, there is a paucity of evidence and lack of guidance to provide effective use of this therapy. A panel of experts was convened to provide guidance regarding the appropriate use of negative-pressure wound therapy with instillation. A face-to-face meeting was held where the available evidence was discussed and individual clinical experience with this therapy was shared. Follow-up communication among the panelists continued until consensus was achieved. The final consensus recommendations were derived through more than 80 percent agreement among the panelists. Nine consensus statements were generated that address the appropriate use of negative-pressure wound therapy with instillation. The question of clinical effectiveness of this therapy was not directly addressed by the consensus panel. This document serves as preliminary guidelines until more robust evidence emerges that will support or modify these consensus recommendations.

  3. The effects of acebutolol and metoprolol on walking distances and distal blood pressure in hypertensive patients with intermittent claudication

    DEFF Research Database (Denmark)

    Svendsen, T L; Jelnes, Rolf; Tønnesen, K H

    1986-01-01

    The effects of acebutolol (with intrinsic sympathomimetic activity (ISA] and metoprolol (without ISA) on arm blood pressure, ankle systolic blood pressure, claudication distances (CD) and maximal walking distances (MWD) were compared in patients with essential hypertension and intermittent...... claudication. Fourteen patients participated in a long-term, open, randomized cross-over study. After randomization the patients received either acebutolol, 200 mg b.i.d., or metoprolol, 100 mg b.i.d. After eight weeks the drugs were shifted and after another eight weeks they were withdrawn. Arm and ankle...... blood pressure, CD and MWD were determined before randomization and after 4, 8, 12 and 16 weeks, and again 4-6 weeks after withdrawal of the drugs. The arm blood pressure was reduced by 20/13 mmHg after acebutolol and by 22/21 mmHg after metoprolol. In spite of a significant decrease in arm blood...

  4. Intermittent fasting dietary restriction regimen negatively influences reproduction in young rats: a study of hypothalamo-hypophysial-gonadal axis.

    Science.gov (United States)

    Kumar, Sushil; Kaur, Gurcharan

    2013-01-01

    Nutritional infertility is very common in societies where women fail to eat enough to match their energy expenditure and such females often present as clinical cases of anorexia nervosa. The cellular and molecular mechanisms that link energy balance and central regulation of reproduction are still not well understood. Peripheral hormones such as estradiol, testosterone and leptin, as well as neuropeptides like kisspeptin and neuropeptides Y (NPY) play a potential role in regulation of reproduction and energy balance with their primary target converging on the hypothalamic median eminence-arcuate region. The present study was aimed to explore the effects of negative energy state resulting from intermittent fasting dietary restriction (IF-DR) regimen on complete hypothalamo-hypophysial-gonadal axis in Wistar strain young female and male rats. Significant changes in body weight, blood glucose, estrous cyclicity and serum estradiol, testosterone and LH level indicated the negative role of IF-DR regimen on reproduction in these young animals. Further, it was elucidated whether serum level of metabolic hormone, leptin plays a mechanistic role in suppressing hypothalamo-hypophysial-gonadal (HPG) axis via energy regulators, kisspeptin and NPY in rats on IF-DR regimen. We also studied the effect of IF-DR regimen on structural remodeling of GnRH axon terminals in median eminence region of hypothalamus along with the glial cell marker, GFAP and neuronal plasticity marker, PSA-NCAM using immunostaining, Western blotting and RT-PCR. Together these data suggest that IF-DR regimen negatively influences reproduction in young animals due to its adverse effects on complete hypothalamus-hypophysial-gonadal axis and may explain underlying mechanism(s) to understand the clinical basis of nutritional infertility.

  5. Intermittent fasting dietary restriction regimen negatively influences reproduction in young rats: a study of hypothalamo-hypophysial-gonadal axis.

    Directory of Open Access Journals (Sweden)

    Sushil Kumar

    Full Text Available Nutritional infertility is very common in societies where women fail to eat enough to match their energy expenditure and such females often present as clinical cases of anorexia nervosa. The cellular and molecular mechanisms that link energy balance and central regulation of reproduction are still not well understood. Peripheral hormones such as estradiol, testosterone and leptin, as well as neuropeptides like kisspeptin and neuropeptides Y (NPY play a potential role in regulation of reproduction and energy balance with their primary target converging on the hypothalamic median eminence-arcuate region. The present study was aimed to explore the effects of negative energy state resulting from intermittent fasting dietary restriction (IF-DR regimen on complete hypothalamo-hypophysial-gonadal axis in Wistar strain young female and male rats. Significant changes in body weight, blood glucose, estrous cyclicity and serum estradiol, testosterone and LH level indicated the negative role of IF-DR regimen on reproduction in these young animals. Further, it was elucidated whether serum level of metabolic hormone, leptin plays a mechanistic role in suppressing hypothalamo-hypophysial-gonadal (HPG axis via energy regulators, kisspeptin and NPY in rats on IF-DR regimen. We also studied the effect of IF-DR regimen on structural remodeling of GnRH axon terminals in median eminence region of hypothalamus along with the glial cell marker, GFAP and neuronal plasticity marker, PSA-NCAM using immunostaining, Western blotting and RT-PCR. Together these data suggest that IF-DR regimen negatively influences reproduction in young animals due to its adverse effects on complete hypothalamus-hypophysial-gonadal axis and may explain underlying mechanism(s to understand the clinical basis of nutritional infertility.

  6. Perceived social pressure not to experience negative emotion is linked to selective attention for negative information.

    Science.gov (United States)

    Bastian, Brock; Pe, Madeline Lee; Kuppens, Peter

    2017-02-01

    Social norms and values may be important predictors of how people engage with and regulate their negative emotional experiences. Previous research has shown that social expectancies (the perceived social pressure not to feel negative emotion (NE)) exacerbate feelings of sadness. In the current research, we examined whether social expectancies may be linked to how people process emotional information. Using a modified classical flanker task involving emotional rather than non-emotional stimuli, we found that, for those who experienced low levels of NE, social expectancies were linked to the selective avoidance of negative emotional information. Those who experienced high levels of NE did not show a selective avoidance of negative emotional information. The findings suggest that, for people who experience many NEs, social expectancies may lead to discrepancies between how they think they ought to feel and the kind of emotional information they pay attention to.

  7. Long-term intermittent pharmacological therapy of uterine fibroids – a possibility to avoid hysterectomy and its negative consequences

    Directory of Open Access Journals (Sweden)

    Anita Olejek

    2016-03-01

    Full Text Available Uterine fibroids are found in almost 20-40% of women of reproductive age. For each woman an individualised treatment method should be applied because the hysterectomy procedure is not a good option in every case. The uterus is an organ necessary not only in reproduction. Its removal may result in: pelvic floor dysfunction and stress urinary incontinence, negative impair on life quality, depressive disorders, increased risk of cardiovascular and neurodegenerative diseases, and higher incidence of neoplastic disease. According to the last scientific reports, selective progesterone receptor modulators are the effective therapeutic option in uterine fibroids in women of reproductive age because progesterone is an important factor in their pathogenesis. Ulipristal acetate (UPA is a progesterone receptor antagonist. It inhibits cell proliferation and angiogenesis in uterine fibroids and also reduces collagen deposits in extracellular matrix. Significant data concerning ulipristal acetate efficacy have been provided by scientific research, especially from the consecutive PEARL studies. Oral ulipristal acetate effectively and safely controls bleeding and pain in patients with symptomatic fibroids. It reduces fibroid volume and restores quality of life. The results of UPA long-term intermittent treatment are largely maintained during the off-treatment periods.

  8. An anesthetic management of negative pressure pulmonary edema

    Directory of Open Access Journals (Sweden)

    Dipti Raj

    2016-01-01

    Full Text Available Negative pressure pulmonary edema (NPPE is one of the common complications of upper airway obstruction seen by anesthesiologist during either in induction or emergence sometimes both. Patients who have experienced NPPE are generally healthy without comorbidities. NPPE is a result of marked decrease in intrathoracic pressure caused by ventilator efforts against a closed glottis resulting in disruption of normal intravascular Starling mechanism, leading to transudation of intravascular protein, and fluids into the pulmonary interstitium. The onset of NPPE is usually rapid and without prompt recognition and intervention, the outcome can be fatal. This case report is of a 40-year-old female adult, who underwent right-sided percutaneous nephrolithotomy for stone in the right kidney otherwise uncomplicated surgical procedure.

  9. Cardiovascular responses of women to lower body negative pressure

    Science.gov (United States)

    Frey, M. A. B.; Mathes, K. L.; Hoffler, G. W.

    1986-01-01

    The effects of lower body negative pressure (LBNP) on the cardiovascular response of 20 women between 23-43 years are evaluated. Calf circumference and cardiovascular data were recorded for women in the follicular and luteal phases of the menstrual cycle at -30, -40, and -50 mm Hg LBNP. The data reveal that the two menstrual phases did not cause differences in the way women respond to LBNP. It is observed that during LBNP calf circumference is enlarged; transthoracic impedance, and heart rate are increased; stroke volume, left ventricular ejection time, the Heather Index of contractility and systolic pressure, and cardiac output are reduced; and total peripheral resistance is elevated. The experimental data are compared to Montgomery et al. (1979). It is noted that the response of women to -50 mm Hg LBNP is similar to that of men; however, women adapt to stresses on the cardiovascular system with greater heart rate adjustments.

  10. Study on the hydrogen negative ion in low pressure discharges

    International Nuclear Information System (INIS)

    Bruneteau, A.M.

    1983-07-01

    A new use of negative hydrogen ions is the production of intense fast neutral atom beams useful in plasma heating in thermonuclear heating. That is one of the reasons that started this study. The density of negative hydrogen ions in diffusion, and multipole-type low pressure (10 -3 - 10-2 Torr) discharges is deduced from the various formation and destruction processes of the species present in these discharges. The H - ions are essentially produced by dissociative attachment to vibrationally excited molecules and destroyed by processes the relative importance of which is discussed as a function of the discharge parameters. The experimental study of the density of the H - ions, measured by photodetachment, as a function of these parameters, coroborates the theoretical model [fr

  11. Dynamic isolation technologies in negative pressure isolation wards

    CERN Document Server

    Xu, Zhonglin

    2017-01-01

    This book presents novel design principles and technologies for dynamic isolation based on experimental studies. These approaches have now become the local standard in Beijing and are currently being promoted for use nationwide. Further, the book provides details of measures and guidelines for the design process. Departing from the traditional understanding that isolation wards should be designed with high negative pressure, airtight doors and fresh air, it establishes the basis for designing biological clean rooms, including isolation wards, using a simple and convenient scientific approach. This book is intended for designers, engineers, researchers, hospital management staff and graduate students in heating ventilation air conditioning (HVAC), air cleaning technologies and related areas.

  12. Negative pressure pulmonary edema in healthy cosmetic surgery patients.

    Science.gov (United States)

    Dieu, Tam; Upjohn, Edward

    2003-01-01

    Anesthetic complications are uncommon in young and healthy patients undergoing cosmetic surgery. We report 2 cases of negative pressure pulmonary edema (NPPE) in young patients, 1 who underwent rhinoplasty and another who underwent augmentation mammaplasty and suction-assisted lipoplasty of the thighs and buttocks This rare and potentially fatal complication requires admission to an intensive-care unit and delayed discharge. Although cases of NPPE have been reported in the medical and anesthetic literature, NPPE in plastic surgery has never been reported previously.

  13. Solvation pressure as real pressure: I. Ethanol and starch under negative pressure

    CERN Document Server

    Uden, N W A V; Faux, D A; Tanczos, A C; Howlin, B; Dunstan, D J

    2003-01-01

    The reality of the solvation pressure generated by the cohesive energy density of liquids is demonstrated by three methods. Firstly, the Raman spectrum of ethanol as a function of cohesive energy density (solvation pressure) in ethanol-water and ethanol-chloroform mixtures is compared with the Raman spectrum of pure ethanol under external hydrostatic pressure and the solvation pressure and hydrostatic pressure are found to be equivalent for some transitions. Secondly, the bond lengths of ethanol are calculated by molecular dynamics modelling for liquid ethanol under pressure and for ethanol vapour. The difference in bond lengths between vapour and liquid are found to be equivalent to the solvation pressure for the C-H sub 3 , C-H sub 2 and O-H bond lengths, with discrepancies for the C-C and C-O bond lengths. Thirdly, the pressure-induced gelation of potato starch is measured in pure water and in mixtures of water and ethanol. The phase transition pressure varies in accordance with the change in solvation pre...

  14. Apical Negative Pressure irrigation presents tissue compatibility in immature teeth

    Directory of Open Access Journals (Sweden)

    Carolina Maschietto Pucinelli

    Full Text Available Abstract Aim: To compare the apical negative pressure irrigation (ANP with conventional irrigation in the teeth of immature dogs with apical periodontitis. Methods: Fifty-two immature pre-molar root canals were randomly assigned into 4 groups: ANP (n=15; conventional irrigation (n=17; healthy teeth (control (n = 10; and teeth with untreated apical periodontitis (control (n=10. After induction of apical periodontitis, teeth were instrumented using EndoVac® (apical negative pressure irrigation or conventional irrigation. The animals were euthanized after 90 days. The sections were stained by HE and analyzed under conventional and fluorescence microscopy. TRAP histoenzymology was also performed. Statistical analyses were performed with the significance level set at 5%. Results: There was difference in the histopathological parameters between ANP and conventional groups (p0.05. However, a lower number of osteoclasts was observed in the ANP group (p<0.05. Conclusion: The EndoVac® irrigation system presented better biological results and more advanced repair process in immature teeth with apical periodontitis than the conventional irrigation system, confirming the hypothesis.

  15. Management of Pharyngocutaneous Fistula With Negative-Pressure Wound Therapy.

    Science.gov (United States)

    Teixeira, Sérgio; Costa, Joana; Bartosch, Isabel; Correia, Bernardo; Silva, Álvaro

    2017-06-01

    Pharyngocutaneous fistula is a common complication of laryngopharyngeal surgery and is associated with increased morbidity and mortality. Beyond the classical management, negative-pressure wound therapy (NPWT) can be an alternative and effective treatment. Two patients with pT3N0M0 squamous cell carcinoma of pyriform sinus were subjected to total laryngectomy and pharyngoesophageal reconstruction of a circular (patient 1) and an anterior wall defect (patient 2) with radial forearm free flap and pectoralis major muscle flap, respectively. Both developed a pharyngocutaneous fistula and NPWT was used.A significant decrease of the fistula aperture and exudate was observed after 22 and 21 days of NPWT in patients 1 and 2, respectively. After that standard wound care was instituted and closure of the fistulae was accomplished in 5 and 7 days, respectively. Negative-pressure wound therapy can be an effective treatment for pharyngocutaneous fistula closure, either in the setting of fistulae that persist besides multiple surgical revisions using muscle flaps or as a first-line therapy when fistulae develops.

  16. Negative pressure wound therapy for treating leg ulcers.

    Science.gov (United States)

    Dumville, Jo C; Land, Lucy; Evans, Debra; Peinemann, Frank

    2015-07-14

    Leg ulcers are open skin wounds that occur between the ankle and the knee that can last weeks, months or even years and are a consequence of arterial or venous valvular insufficiency. Negative pressure wound therapy (NPWT) is a technology that is currently used widely in wound care and is promoted for use on wounds. NPWT involves the application of a wound dressing to the wound, to which a machine is attached. The machine applies a carefully controlled negative pressure (or vacuum), which sucks any wound and tissue fluid away from the treated area into a canister. To assess the effects of negative pressure wound therapy (NPWT) for treating leg ulcers in any care setting. For this review, in May 2015 we searched the following databases: the Cochrane Wounds Group Specialised Register (searched 21 May 2015); the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2015, Issue 4); Ovid MEDLINE (1946 to 20 May 2015); Ovid MEDLINE (In-Process & Other Non-Indexed Citations 20 May 2015); Ovid EMBASE (1974 to 20 May 2015); EBSCO CINAHL (1982 to 21 May 2015). There were no restrictions based on language or date of publication. Published or unpublished randomized controlled trials (RCTs) comparing the effects of NPWT with alternative treatments or different types of NPWT in the treatment of leg ulcers. Two review authors independently performed study selection, risk of bias assessment and data extraction. We included one study, with 60 randomized participants, in the review. The study population had a range of ulcer types that were venous arteriolosclerotic and venous/arterial in origin. Study participants had recalcitrant ulcers that had not healed after treatment over a six-month period. Participants allocated to NPWT received continuous negative pressure until they achieved 100% granulation (wound preparation stage). A punch skin-graft transplantation was conducted and the wound then exposed to further NPWT for four days followed by standard care

  17. Physical fitness and cardiovascular response to lower body negative pressure

    Science.gov (United States)

    Raven, P. B.; Rohm-Young, D.; Blomqvist, C. G.

    1984-01-01

    Klein et al. (1977) have questioned the concept of endurance training as an appropriate means of preparing for prolonged space flights. Their opinion was mainly based on reports of endurance athletes who had a decreased tolerance to orthostatic or gravitational stress induced by lower body negative pressure (LBNP), upright tilt, or whole body water immersion. The present investigation had the objective to determine if the hemodynamic response to LBNP is different between a high and average fit group of subjects. In addition, the discrete aspect of cardiovascular function which had been altered by chronic training was to be identified. On the basis of the results of experiments conducted with 14 young male volunteers, it is concluded that the reflex response to central hypovolemia is altered by endurance exercise training.

  18. High frequency jet ventilation and intermittent positive pressure ventilation. Effect of cerebral blood flow in patients after open heart surgery

    International Nuclear Information System (INIS)

    Pittet, J.F.; Forster, A.; Suter, P.M.

    1990-01-01

    Attenuation of ventilator-synchronous pressure fluctuations of intracranial pressure has been demonstrated during high frequency ventilation in animal and human studies, but the consequences of this effect on cerebral blood flow have not been investigated in man. We compared the effects of high frequency jet ventilation and intermittent positive pressure ventilation on CBF in 24 patients investigated three hours after completion of open-heart surgery. The patients were investigated during three consecutive periods with standard sedation (morphine, pancuronium): a. IPPV; b. HFJV; c. IPPV. Partial pressure of arterial CO 2 (PaCO 2 : 4.5-5.5 kPa) and rectal temperature (35.5 to 37.5 degree C) were maintained constant during the study. The CBF was measured by intravenous 133 Xe washout technique. The following variables were derived from the cerebral clearance of 133 Xe: the rapid compartment flow, the initial slope index, ie, a combination of the rapid and the slow compartment flows, and the ratio of fast compartment flow over total CBF (FF). Compared to IPPV, HFJV applied to result in the same mean airway pressure did not produce any change in pulmonary gas exchange, mean systemic arterial pressure, and cardiac index. Similarly, CBF was not significantly altered by HFJV. However, important variations of CBF values were observed in three patients, although the classic main determinants of CBF (PaCO 2 , cerebral perfusion pressure, Paw, temperature) remained unchanged. Our results suggest that in patients with normal systemic hemodynamics, the effects of HFJV and IPPV on CBF are comparable at identical levels of mean airway pressure

  19. Homogeneous nucleation in liquid nitrogen at negative pressures

    Energy Technology Data Exchange (ETDEWEB)

    Baidakov, V. G., E-mail: baidakov@itp.uran.ru; Vinogradov, V. E.; Pavlov, P. A. [Russian Academy of Sciences, Institute of Thermal Physics, Ural Branch (Russian Federation)

    2016-10-15

    The kinetics of spontaneous cavitation in liquid nitrogen at positive and negative pressures has been studied in a tension wave formed by a compression pulse reflected from the liquid–vapor interface on a thin platinum wire heated by a current pulse. The limiting tensile stresses (Δp = p{sub s}–p, where p{sub s} is the saturation pressure), the corresponding bubble nucleation frequencies J (10{sup 20}–10{sup 22} s{sup –1} m{sup –3}), and temperature induced nucleation frequency growth rate G{sub T} = dlnJ/dT have been experimentally determined. At T = 90 K, the limiting tensile stress was Δp = 8.3 MPa, which was 4.9 MPa lower than the value corresponding to the boundary of thermodynamic stability of the liquid phase (spinodal). The measurement results were compared to classical (homogeneous) nucleation theory (CNT) with and without neglect of the dependence of the surface tension of critical bubbles on their dimensions. In the latter case, the properties of new phase nuclei were described in terms of the Van der Waals theory of capillarity. The experimental data agree well with the CNT theory when it takes into account the “size effect.”.

  20. Negative pressure wound therapy in patients with diabetic foot.

    Science.gov (United States)

    Ulusal, Ali Engin; Sahin, M Sükrü; Ulusal, Betül; Cakmak, Gökhan; Tuncay, Cengiz

    2011-01-01

    In this study our aim was to compare the results of standard dressing treatment to negative pressure wound therapy (NPWT) performed with a vacuum-assisted closure (VAC) device in patients with diabetic foot ulcers. We assessed the results of 35 patients treated for diabetic foot ulcer between 2006 and 2008. Of these cases, 20 (4 women and 16 men; mean age: 66 years; range: 52-90 years) were treated with standard wet dressings and 16 feet in 15 patients (10 men, 5 women; mean age: 58.9 years; range: 42-83 years) with VAC therapy. The success of treatment was evaluated in terms of hospitalization length and rate of limb salvation. The average hospitalization period with VAC treatment was 32 days compared to 59 days with standard dressing treatment. All patients treated with standard dressings eventually had to undergo amputation. However, the amputation rate was 37% in the VAC treated group and 88% of patients had a functional extremity at the end of treatment. VAC therapy, together with debridement and appropriate antibiotic therapy, enables a higher rate of limb salvage, especially in Wagner Grade 3 and Grade 4 ulcers.

  1. Long-term performance of air-side heat transfer and pressure drop for finned tube evaporators of air conditioners under intermittent operation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pu, Hui; Ding, Guo-liang; Ma, Xiao-kui; Hu, Hai-tao [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Gao, Yi-feng [International Copper Association Shanghai Office, 381 Huaihaizhong Road, Shanghai 200020 (China)

    2010-01-15

    In this study, the effects of long-term intermittent operations on the air-side heat transfer and pressure drop performance of finned tube evaporators of air conditioners were investigated by experiments on an aluminum-fin evaporator and a copper-fin evaporator. In order to simulate intermittent operations of on-off controlled air conditioners, the temperatures of the two evaporators changed to 5 {+-} 0.5 C at first and then to 27 {+-} 0.5 C repeatedly. The repetition number was up to 4800, and the air-side heat transfer and pressure drop of the two evaporators were tested after every 300 repetitions. The test results indicate that after long-term intermittent operations, the air-side heat transfer coefficient decreases and the pressure drop increases. The variations of the heat transfer coefficient and the pressure drop are more obvious at lower inlet air velocity, and the influence of long-term intermittent operations on the aluminum-fin evaporator is greater than that on the copper-fin evaporator. (author)

  2. Intermittent preventive treatment of malaria in pregnancy with mefloquine in HIV-negative women: a multicentre randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Raquel González

    2014-09-01

    Full Text Available Intermittent preventive treatment in pregnancy (IPTp with sulfadoxine-pyrimethamine (SP is recommended by WHO to prevent malaria in African pregnant women. The spread of SP parasite resistance has raised concerns regarding long-term use for IPT. Mefloquine (MQ is the most promising of available alternatives to SP based on safety profile, long half-life, and high efficacy in Africa. We evaluated the safety and efficacy of MQ for IPTp compared to those of SP in HIV-negative women.A total of 4,749 pregnant women were enrolled in an open-label randomized clinical trial conducted in Benin, Gabon, Mozambique, and Tanzania comparing two-dose MQ or SP for IPTp and MQ tolerability of two different regimens. The study arms were: (1 SP, (2 single dose MQ (15 mg/kg, and (3 split-dose MQ in the context of long lasting insecticide treated nets. There was no difference on low birth weight prevalence (primary study outcome between groups (360/2,778 [13.0%] for MQ group and 177/1,398 (12.7% for SP group; risk ratio [RR], 1.02 (95% CI 0.86-1.22; p=0.80 in the ITT analysis. Women receiving MQ had reduced risks of parasitemia (63/1,372 [4.6%] in the SP group and 88/2,737 [3.2%] in the MQ group; RR, 0.70 [95% CI 0.51-0.96]; p=0.03 and anemia at delivery (609/1,380 [44.1%] in the SP group and 1,110/2743 [40.5%] in the MQ group; RR, 0.92 [95% CI 0.85-0.99]; p=0.03, and reduced incidence of clinical malaria (96/551.8 malaria episodes person/year [PYAR] in the SP group and 130/1,103.2 episodes PYAR in the MQ group; RR, 0.67 [95% CI 0.52-0.88]; p=0.004 and all-cause outpatient attendances during pregnancy (850/557.8 outpatients visits PYAR in the SP group and 1,480/1,110.1 visits PYAR in the MQ group; RR, 0.86 [0.78-0.95]; p=0.003. There were no differences in the prevalence of placental infection and adverse pregnancy outcomes between groups. Tolerability was poorer in the two MQ groups compared to SP. The most frequently reported related adverse events were dizziness

  3. Negative pressure therapy for the treatment of complex wounds.

    Science.gov (United States)

    Lima, Renan Victor Kümpel Schmidt; Coltro, Pedro Soler; Farina, Jayme Adriano

    2017-01-01

    The objective of this study is to evaluate the effectiveness of negative pressure therapy (NPT) in the treatment of complex wounds, with emphasis on its mechanisms of action and main therapeutic indications. We searched the Pubmed / Medline database for articles published from 1997 to 2016, and selected the most relevant ones. The mechanisms of action of NPT involveboth physical effects, such as increased perfusion, control of edema and exudate, reduction of wound dimensions and bacterial clearance, and biological ones, such as the stimulation of granulation tissue formation, microdeformations and reduction of Inflammatory response. The main indications of NPT are complex wounds, such as pressure ulcers, traumatic wounds, operative wound dehiscences, burns, necrotizing wounds, venous ulcers, diabetic wounds, skin grafts, open abdomen, prevention of complications in closed incisions and in the association with instillation of solutions in infected wounds. RESUMO O objetivo desse estudo é avaliar a eficácia da terapia por pressão negativa (TPN) no tratamento de feridas complexas, com ênfase em seus mecanismos de ação e principais indicações terapêuticas. Foi realizada revisão na base de dados Pubmed / Medline, em artigos publicados de 1997 a 2016, e selecionados os mais relevantes. O mecanismo de ação da TPN envolve efeitos físicos, como o aumento da perfusão, controle do edema e do exsudato, redução das dimensões da ferida e depuração bacteriana, e biológicos, como o estímulo à formação de tecido de granulação, microdeformações e redução da resposta inflamatória local. As principais indicações da TPN são as feridas complexas como úlceras por pressão, feridas traumáticas, deiscências de ferida operatória, queimaduras, feridas necrotizantes, úlceras venosas, feridas diabéticas, os enxertos de pele, o abdome aberto, na prevenção de complicações em incisões fechadas e na associação com instilação de soluções em feridas

  4. A portable, disposable system for negative-pressure wound therapy.

    Science.gov (United States)

    Brandon, Tanya

    Negative-pressure wound therapy (NPWT) imparts a number of clinical effects that promote a healing response and, as such, is a well-established means of treating a variety of wound types. Historically, the technique has been primarily used in the hospital setting; however, the introduction of more portable devices has led to an increase in the use of NPWT in the homecare setting, thereby facilitating early discharge of patients from hospital and continuity of care in the community. Portable NPWT devices also have the potential to impact positively on patients' quality of life, allowing increased mobility and freedom to undertake normal activities of daily living. Following the development of its standard Avance® NPWT system and associated dressing kits, Mölnlycke Health Care (Gothenburg, Sweden) has introduced a single-patient-use, disposable NPWT system; Avance Solo. This has been developed with a view to maximising patient freedom and mobility, providing a single-patient-use NPWT solution for multi-week treatment to allow quick and easy discharge of patients from hospital to home, and reducing some of the challenges of logistics and administration associated with the provision of NPWT for the caregiver. As with the standard NPWT system, the single-patient use system is supplied with a number of products incorporating Safetac® adhesive technology to minimise the risk of patients suffering unnecessary pain and trauma associated with dressing changes. This article presents a series of case studies describing procedures and outcomes following the application of the Avance Solo single-patient-use system.

  5. Active Negative Pressure Peritoneal Therapy After Abbreviated Laparotomy

    Science.gov (United States)

    Roberts, Derek J.; Faris, Peter D.; Ball, Chad G.; Kubes, Paul; Tiruta, Corina; Xiao, Zhengwen; Holodinsky, Jessalyn K.; McBeth, Paul B.; Doig, Christopher J.; Jenne, Craig N.

    2015-01-01

    Objective: To determine whether active negative pressure peritoneal therapy with the ABThera temporary abdominal closure device reduces systemic inflammation after abbreviated laparotomy. Background: Excessive systemic inflammation after abdominal injury or intra-abdominal sepsis is associated with poor outcomes. Methods: We conducted a single-center, randomized controlled trial. Forty-five adults with abdominal injury (46.7%) or intra-abdominal sepsis (52.3%) were randomly allocated to the ABThera (n = 23) or Barker's vacuum pack (n = 22). On study days 1, 2, 3, 7, and 28, blood and peritoneal fluid were collected. The primary endpoint was the difference in the plasma concentration of interleukin-6 (IL-6) 24 and 48 hours after temporary abdominal closure application. Results: There was a significantly lower peritoneal fluid drainage from the ABThera at 48 hours after randomization. Despite this, there was no difference in plasma concentration of IL-6 at baseline versus 24 (P = 0.52) or 48 hours (P = 0.82) between the groups. There was also no significant intergroup difference in the plasma concentrations of IL-1β, −8, −10, or −12 p70 or tumor necrosis factor α between these time points. The cumulative incidence of primary fascial closure at 90 days was similar between groups (hazard ratio, 1.6; 95% confidence interval, 0.82–3.0; P = 0.17). However, 90-day mortality was improved in the ABThera group (hazard ratio, 0.32; 95% confidence interval, 0.11–0.93; P = 0.04). Conclusions: This trial observed a survival difference between patients randomized to the ABThera versus Barker's vacuum pack that did not seem to be mediated by an improvement in peritoneal fluid drainage, fascial closure rates, or markers of systemic inflammation. Trial Registration: ClinicalTrials.gov identifier NCT01355094. PMID:25536308

  6. Calibration methods for negative gauge pressure down to  ‑100 kPa

    Science.gov (United States)

    Bentouati, Djilali; Durgut, Yasin; Otal, Pierre; Plimmer, Mark; Pražák, Dominik; Sabuga, Wladimir; Ehlers, Sven; Sınır, Ekrem

    2018-03-01

    The measurement of negative gauge pressure is a field of increasing importance in science and industry. One of the main aims of the EMPIR Joint Research Project 14IND 06 pres2vac is to develop guidelines for it. We present a comparison of three different methods for measuring negative gauge pressure: (i) using two absolute pressure measuring instruments, (ii) generating a negative gauge pressure in the bell jar of the pressure balance, and (iii) using a ‘hanging piston’ pressure balance. The advantages and drawbacks are discussed and some preliminary results presented.

  7. Mechanical ventilation in the newborn; a simplified approach. Part 1: Intermittent positive pressure ventilation.

    Science.gov (United States)

    Muhlethaler, Vincent; Malcolm, Girvan

    2012-08-01

    Positive pressure ventilation (PPV) is a frequent intervention in the neonatal intensive care unit. This article is directed towards paediatricians in training and attempts to cover the basics of PPV without being too technical. To do so we have employed an extensive use of graphics to illustrate the underlying principles. © 2010 The Authors. Journal of Paediatrics and Child Health © 2010 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  8. Contrastive Analysis and Research on Negative Pressure Beam Tube System and Positive Pressure Beam Tube System for Mine Use

    Science.gov (United States)

    Wang, Xinyi; Shen, Jialong; Liu, Xinbo

    2018-01-01

    Against the technical defects of universally applicable beam tube monitoring system at present, such as air suction in the beam tube, line clogging, long sampling time, etc., the paper analyzes the current situation of the spontaneous combustion fire disaster forecast of mine in our country and these defects one by one. On this basis, the paper proposes a research thought that improving the positive pressure beam tube so as to substitute the negative pressure beam tube. Then, the paper introduces the beam tube monitoring system based on positive pressure technology through theoretical analysis and experiment. In the comparison with negative pressure beam tube, the paper concludes the advantage of the new system and draws the conclusion that the positive pressure beam tube is superior to the negative pressure beam tube system both in test result and test time. At last, the paper proposes prospect of the beam tube monitoring system based on positive pressure technology.

  9. Comparison of intermittent positive pressure breathing and temporary positive expiratory pressure in patients with severe chronic obstructive pulmonary disease.

    Science.gov (United States)

    Nicolini, Antonello; Mollar, Elena; Grecchi, Bruna; Landucci, Norma

    2014-01-01

    Results supporting the use and the effectiveness of positive expiratory, pressure devices in chronic obstructive pulmonary disease (COPD) patients are still controversial, We have tested the hypothesis that adding TPEP or IPPB to standard pharmacological therapy may provide additional clinical benefit over, pharmacological therapy only in patients with severe COPD. Fourty-five patients were randomized in three groups: a group was treated; with IPPB,a group was treated with TPEP and a group with pharmacological; therapy alone (control group). Primary outcome measures included the measurement of scale or, questionnaire concerning dyspnea (MRC scale),dyspnea,cough, and, sputum (BCSS) and quality of life (COPD assessment test) (CAT). Secondary, outcome measures were respiratory function testing,arterial blood gas,analysis,and hematological examinations. Both patients in the IPPB group and in the TPEP group showed a significant, improvement in two of three tests (MRC,CAT) compared to the control, group.However,in the group comparison analysis for, the same variables between IPPB group and TPEP group we observed a, significant improvement in the IPPB group (P≤.05 for MRC and P≤.01 for, CAT). The difference of action of the two techniques are evident in the results of, pulmonary function testing: IPPB increases FVC, FEV1, and MIP; this reflects, its capacity to increase lung volume. Also TPEP increases FVC and FEV1 (less, than IPPB), but increases MEP, while decreasing total lung capacity and, residual volume. The two techniques (IPPB and TPEP) improves significantly dyspnea; quality of; life tools and lung function in patients with severe COPD. IPPB demonstrated a greater effectiveness to improve dyspnea and quality of life tools (MRC, CAT) than TPEP. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

  10. Involvement of nitric oxide in the wound bed microcirculatory change during negative pressure wound therapy.

    Science.gov (United States)

    Sano, Hitomi; Ichioka, Shigeru

    2015-08-01

    This study investigated the role of nitric oxide (NO) in the mechanism of blood flow increase in the wound bed during negative pressure wound therapy (NPWT). We developed an improved experimental model that allowed visualisation of the wound bed microcirculation under NPWT. Wounds were created on the mouse ear, taking care to preserve the subdermal vascular plexus, because the wound bed microcirculation was visualised using an intravital microscope system. We investigated whether application of a NO synthase inhibitor (N(G) -nitro-l-arginine methyl ester: L-NAME) might diminish the effect of the NPWT in increasing the wound blood flow. The experimental animals were divided into a negative pressure group (negative pressure of -125 mmHg applied to the wound for 5 minutes; n = 8), and a negative pressure plus L-NAME group (administration of L-NAME prior to application of the negative pressure; n = 8). In the negative pressure group, significant increase of blood flow was observed at 1 minute after the negative pressure application, which was sustained until 5 minutes. On the contrary, in the negative pressure plus L-NAME group, no significant changes were observed throughout the period of observation. These findings suggest that NO synthesis is involved in the wound bed microcirculatory change induced by NPWT. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  11. Topical negative pressure therapy Recent experience of the department of plastic surgery at Ibn Sina University Hospital, Rabat, Morocco

    Directory of Open Access Journals (Sweden)

    Abdelmoughit Echchaoui

    2014-12-01

    Full Text Available IntroductionThe topical negative pressure therapy (TNP is a non-invasive method to treat chronic and acute wounds locally, using a continuous or intermittent negative pressure.The objective of this study is to present the first experience of this type of treatment used in clinical cases in our department. By presenting these cases, we highlight indication and efficiency of this new technique applied in relatively complicated situations, at the same time it also allows a significant improvement in treating injuries and chronic wounds.Materials and methodsIn this study, we present the recent experience of the Department of Reconstructive and Plastic Surgery of the University Hospital Center of Avicenne in Rabat. This therapy was used for the first time this year (in 2014, in three young patients who presented with chronic wounds associated with local and general factors that are unfavorable for the healing process.ResultsIn all three of our cases we obtained highly satisfactory clinical results.TNP allows wounds to bud in a shorter time, as well as a fast healing by second intention due to controlled wound healing or split-skin graft without using flaps. This enables to decrease the margin of error, the time and the number of dressing replacements, and to reduce the length of hospital stay.ConclusionThis is an expensive and specific equipment. However, the cost-benefit ratio analysis shows that it is an essential method that should be part of our therapeutic strategies.Keywords: loss of substance, negative pressure, budding, healing.  

  12. Negative chemical pressure effects induced by Y substitution for Ca ...

    Indian Academy of Sciences (India)

    the magnetic chain may be useful to the overall understanding of the novel magnetism of the parent compound. Keywords. Spin-chains; Ca3Co2O6; chemical pressure; magnetic order; quantum tun- neling. PACS Nos 75.50.-y; 75.30.Cr; 75.40.Cx. 1. Introduction. Among spin-chain systems, the compound, Ca3Co2O6 [1,2], ...

  13. Heart rate and blood pressure responses during hypoxic cycles of a 3-week intermittent hypoxia breathing program in patients at risk for or with mild COPD

    Directory of Open Access Journals (Sweden)

    Faulhaber M

    2015-02-01

    Full Text Available Martin Faulhaber,1 Hannes Gatterer,1 Thomas Haider,2 Tobias Linser,1 Nikolaus Netzer,1 Martin Burtscher11Department of Sport Science, University of Innsbruck, Innsbruck, Austria; 2Institute of Veterinary Physiology, University of Zurich, Zurich, SwitzerlandAbstract: The aim of this study was to provide information on heart rate and blood pressure responses during a 3-week intermittent hypoxia breathing program in COPD patients. Sixteen participants with COPD symptoms were randomly assigned to a hypoxia or control group and completed a 3-week intermittent hypoxia breathing program (five sessions per week, each consisting of three to five breathing cycles, each cycle lasting 3–5 minutes with 3-minute breaks between cycles. During the breathing cycles, the hypoxia group received hypoxic air (inspired fraction of oxygen 15%–12%, whereas the control group received normal air (sham hypoxia. During the breaks, all participants breathed normoxic room air. Arterial oxygen saturation, systolic and diastolic blood pressure, and heart rate were measured during the normoxic and hypoxic/sham hypoxic periods. For each breathing cycle, changes from normoxia to hypoxia/sham hypoxia were calculated, and changes were averaged for each of the 15 sessions and for each week. Changes in arterial oxygen saturation were significantly different between groups in the course of the 3 weeks (two-way analysis of variance for repeated measures, with post hoc differences in weeks 1, 2, and 3. During the course of the intermittent hypoxia application, no between-group differences were detected for blood pressure or rate pressure product values. Changes in heart rate were significantly different between groups in the course of the 3 weeks (two-way analysis of variance for repeated measures, with post hoc differences only in week 3. Averages over all 15 sessions were significantly higher in the hypoxia group for heart rate and rate pressure product, and tended to be

  14. A Comparison between Nasal Intermittent Positive Pressure Ventilation and Nasal Continuous Positive Airway Pressure Ventilation in the Treatment of Neonatal Respiratory Distress Syndrome

    Directory of Open Access Journals (Sweden)

    Ahmad Shah Farhat

    2015-12-01

    Full Text Available Background: Nasal intermittent positive pressure ventilation (NIPPV is a non-invasive ventilatory mode, which delivers mechanical ventilation via nasal tubes or prongs. The present study was conducted to compare the efficacy of NIPPV and nasal continuous positive airway pressure ventilation (NCPAP in reducing the need for intubation in preterm infants with respiratory distress syndrome (RDS. Methods: This randomized, clinical trial was conducted at the neonatal intensive care unit of Imam Reza Hospital, affiliated to Mashhad University of Medical Sciences during eight months since April 2014. Preterm infants with RDS were recruited before showing any indications for endotracheal intubation after birth. The NIPPV and NCPAPV groups were matched in terms of clinical characteristics. Each infant was randomized to receive either NIPPV or NCPAPV immediately after extubation. Nasal ventilation was deemed successful if intubation was not required within at least 72 hours. Brain sonography was carried out on the third day of life in all infants. Data were recorded for all neonates until hospital discharge. Results: In total, 28% (15/53 and 26.4% (14/53 of infants in the NIPPV and NCPAPV groups were intubated within the first 72 h after birth, respectively (P=0.168. Neither of the procedures induced major adverse effects, although the incidence rate and severity of intraventricular hemorrhage were higher in the NIPPV group, compared to the NCPAPV group (P=0.026. Conclusion: Although NIPPV is confirmed as the first-line treatment for the management of neonatal RDS, this mode of ventilation showed no superiority over NCPAPV in eliminating the need for mechanical ventilation in the present study.

  15. Dynamic Leg Exercise Improves Tolerance to Lower Body Negative Pressure

    Science.gov (United States)

    Watenpaugh, D. E.; Ballard, R. E.; Stout, M. S.; Murthy, G.; Whalen, R. T.; Hargens, A. R.

    1994-01-01

    These results clearly demonstrate that dynamic leg exercise against the footward force produced by LBNP substantially improves tolerance to LBNP, and that even cyclic ankle flexion without load bearing also increases tolerance. This exercise-induced increase of tolerance was actually an underestimate, because subjects who completed the tolerance test while exercising could have continued for longer periods. Exercise probably increases LBNP tolerance by multiple mechanisms. Tolerance was increased in part by skeletal muscle pumping venous blood from the legs. Rosenhamer and Linnarsson and Rosenhamer also deduced this for subjects cycling during centrifugation, although no measurements of leg volume were made in those studies: they found that male subjects cycling at 98 W could endure 3 Gz centrifugation longer than when they remained relaxed during centrifugation. Skeletal muscle pumping helps maintain cardiac filling pressure by opposing gravity-, centrifugation-, or LBNP-induced accumulation of blood and extravascular fluid in the legs.

  16. Mechanisms of lower body negative pressure-induced syncope

    Science.gov (United States)

    Davrath, Linda Ruble

    Although extensively investigated, the mechanisms of post-spaceflight orthostatic intolerance have not been elucidated. The working hypothesis was that a markedly reduced left ventricular end-systolic volume (LVESV) would be achieved during progressive, presyncopal-limited LBNP and would cause bradycardia and a fall in blood pressure, thus triggering syncope. Eight healthy men, age 25.1 ± 1.3 years, volunteered for the study. Subjects were exposed to graded levels of LBNP on two separate occasions. Changes in left ventricular end-diastolic volume and LVESV were measured, using two-dimensional echocardiography, at each stage of LBNP from rest to presyncope. Plasma venous blood samples were withdrawn at the end of each stage of the LBNP protocol for the measurement of plasma venous catecholamines and plasma renin activity (PRA). Catecholamines were analyzed by HPLC with electro-chemical detection, and PRA was determined by radioimmunoassay. All subjects reached presyncope during the LBNP. LVESV decreased by 28% at presyncope with no evidence of ventricular cavity obliteration. Norepinephrine (NE) increased by 44% from rest to presyncope, but no epinephrine surge was detected (35% increase from rest to presyncope). These data indicate that it is possible to initiate syncope with only a 28% decrease in LVESV, and that sympatho-inhibition and bradycardia are not required elements for syncope to occur. To investigate the effect of moderate sodium restriction on cardiovascular hemodynamics and orthostatic tolerance, presyncopal LBNP testing was performed. Urinary sodium excretion was significantly higher on the normal-sodium diet when compared with the sodium-restricted diet, but urinary potassium was not different. Cumulative stress index (655 ± 460 on normal-sodium diet vs. 639 ± 388 on sodium-restricted diet) scores were not different. Cardiac volumes, blood pressure and total peripheral resistance were not different at any stage of the LBNP between the diets, nor

  17. Negative-Pressure Hydrocephalus: A Case Report on Successful Treatment Under Intracranial Pressure Monitoring with Bilateral Ventriculoperitoneal Shunts.

    Science.gov (United States)

    Pandey, Sajan; Jin, Yi; Gao, Liang; Zhou, Cheng Cheng; Cui, Da Ming

    2017-03-01

    Negative-pressure hydrocephalus (NegPH), a very rare condition of unknown etiology and optimal treatment, usually presents postneurosurgery with clinical and imaging features of hydrocephalus, but with negative cerebrospinal fluid pressure. We describe a NegPH case of -3 mm Hg intracranial pressure that was successfully treated to achieve 5 mm Hg under continuous intracranial pressure monitoring with horizontal positioning, head down and legs elevated to 10°-15°, neck wrapping for controlled venous drainage, chest and abdomen bandages, infusion of 5% dextrose fluid to lower plasma osmolarity (Na + , 130-135 mmol/L), daily cerebrospinal fluid drainage >200 mL, and arterial blood gas partial pressure of carbon dioxide >40 mm Hg. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. The effect of negative pressure wound therapy with antibacterial dressings or antiseptics on an in vitro wound model.

    Science.gov (United States)

    Matiasek, J; Domig, K J; Djedovic, G; Babeluk, R; Assadian, O

    2017-05-02

    The aim of this study was to investigate the bacterial bioburden in experimental in vitro wounds during the application of conventional negative pressure wound therapy (NPWT), with and without antimicrobial dressings (polyhexanide, silver), against NPWT instillation of octenidine. Experimental wounds produced in an in vitro porcine wound model were homogenously contaminated with bacterial suspension and treated with NPWT and different options. Group A: non-antimicrobial polyurethane foam dressing; group B: antimicrobial polyurethane foam dressing containing silver; group C: antimicrobial gauze dressing containing polyhexanide; group D: non-antimicrobial polyurethane foam dressing intermittently irrigated with octenidine; group E: negative control (non-antimicrobial polyurethane foam dressing without NPWT). Standard biopsies were harvested after 24 and 28 hours. This study demonstrated that the use of NPWT with intermitted instillation of octenidine (group D) or application of silver-based polyurethane foam dressings (group B) is significantly superior against Staphylococcus aureus colonisation in experimental wounds compared with non-antimicrobial polyurethane foam dressing (group A) after 48 hours. Surprisingly, the polyhexanide-based dressing (group C) used in this model showed no statistical significant effect compared with the control group (group E) after 24 or 48 hours of treatment. Both intermitted instillation of octenidine and silver-based dressings in standard NPWT were significantly superior compared with non-antimicrobial polyurethane foam dressings or PHMB coated gauze dressing after 48 hours.

  19. Negative-pressure therapy versus standard wound care: a meta-analysis of randomized trials.

    Science.gov (United States)

    Suissa, Daniel; Danino, Alain; Nikolis, Andreas

    2011-11-01

    Several randomized controlled trials comparing negative-pressure therapy to standard wound care for chronic wounds have been published. Although these studies suggest a benefit for negative-pressure therapy, the majority of the review articles on the topic conclude that the studies are inconclusive. The authors conducted a quantitative meta-analysis of the effectiveness of negative-pressure therapy for the management of chronic wounds. The MEDLINE, EMBASE, and Cochrane databases were searched from 1993 to March of 2010 for randomized controlled trials comparing negative-pressure therapy to standard wound care for chronic wounds. Measures of wound size and time to healing, along with the corresponding p values, were extracted from the randomized controlled trials. Relative change ratios of wound size and ratios of median time to healing were combined using a random effects model for meta-analysis. Ten trials of negative-pressure therapy versus standard wound care were found. In the negative-pressure therapy group, wound size had decreased significantly more than in the standard wound care group (relative change ratio, 0.77; 95 percent confidence interval, 0.63 to 0.96). Time to healing was significantly shorter in the negative-pressure therapy group in comparison with the standard wound care group (ratio of median time to healing, 0.74; 95 percent confidence interval, 0.70 to 0.78). This quantitative meta-analysis of randomized trials suggests that negative-pressure therapy appears to be an effective treatment for chronic wounds. An effect of publication bias cannot be ruled out. Therapeutic, II.

  20. Management of High-Voltage Burns of the Hand and Wrist with Negative Pressure Dressing

    Directory of Open Access Journals (Sweden)

    Nazım Gümüş

    2017-12-01

    Full Text Available Objective: Negative pressure dressing stimulates wound healing by promoting cellular proliferation and regeneration. It also removes interstitial edema and increases local blood flow, resulting in rapid growth of the granulation tissue. We used the dressing method in deep hand and wrist burns caused by high-voltage electrical current, which leads to progressive tissue necrosis, elevated compartment pressure, and deep tissue edema, to reveal if subatmospheric pressure could limit the zone of injury or ongoing tissue necrosis after electrical burn. Material and Methods: Six hands of five patients, who came in contact with high-voltage electrical wire carrying more than 1000 volts, are presented in this study. Hands and wrists were seriously injured and contracted. After the initial treatment involving fluid resuscitation, fasciotomy, carpal tunnel release, and debridement, a negative pressure dressing was applied to the wounds of hand, wrist, and forearm with 125 mm Hg continuous pressure, and maintained for 20 days. Results: When negative pressure dressing was stopped on the 20th day, significant granulation tissue developed over the hand and forearm wounds. However, wrist wounds needed more debridement and repeated dressings because of the presence of necrosis. Edema of the hands subsided significantly during the use of negative pressure dressing. Time to closure for hand and forearm wounds decreased considerably. Moreover, in one wrist, spontaneous closure was achieved at about one month. All hands except one treated with negative pressure dressing could be saved from amputation; however, significant tissue loss developed, needing complex reconstruction procedures. One hand was amputated because of the permanent loss of blood perfusion. Conclusion: The management of high-voltage burns of hand and wrist with subatmospheric pressure appears to be capable of reducing hand edema and accelerating closure of the wounds. It seems that negative

  1. Experimental study of a negative corona in atmospheric-pressure argon

    International Nuclear Information System (INIS)

    Dandaron, G.-N. B.; Baldanov, B. B.

    2007-01-01

    Results are presented from experimental studies of a negative point-to-plane dc corona in atmospheric-pressure argon. Several operating modes are identified: a hysteresis region, a repetitive mode, and a glow-discharge mode. The effect of gas-dynamic parameters on the characteristics of a repetitive negative corona is investigated

  2. Atrial distension, arterial pulsation, and vasopressin release during negative pressure breathing in humans

    DEFF Research Database (Denmark)

    Pump, B; Damgaard, M; Gabrielsen, A

    2001-01-01

    During an antiorthostatic posture change, left atrial (LA) diameter and arterial pulse pressure (PP) increase, and plasma arginine vasopressin (AVP) is suppressed. By comparing the effects of a 15-min posture change from seated to supine with those of 15-min seated negative pressure breathing...... in eight healthy males, we tested the hypothesis that with similar increases in LA diameter, suppression of AVP release is dependent on the degree of increase in PP. LA diameter increased similarly during the posture change and negative pressure breathing (-9 to -24 mmHg) from between 30 and 31 +/- 1 to 34...... +/- 1 mm (P breathing from 36 +/- 3 to 42 +/- 3 mmHg (P

  3. Application of vacuum-assisted closure in seawater-immersed wound treatment under different negative pressures.

    Science.gov (United States)

    Cao, L; Peng, M M; Sun, J J; Yu, X C; Shi, B

    2015-06-11

    The therapeutic effect of vacuum-assisted closure (VAC) has been confirmed in many types of complex wounds, but there are few relevant reports regarding seawater-immersed wounds. The aim of this study was to determine the effect of VAC on seawater-immersed wound healing under different negative pressures and explore the optimal negative pressure value. Four purebred miniature pigs were used as the experimental animal models. Four acute, symmetrical wounds were made on each side of the spine and designated as the experimental group (wounds with 2 h of seawater immersion) and the control group (wounds without seawater immersion). Wounds were divided into a conventional dressing group and 3 further groups with different VAC therapies (negative pressure at either 120, 180, or 240 mmHg). The extent of wound healing, and speed of granulation growth and re-epithelialization were measured. Bacterial flora distribution in the wounds was observed, and fibronectin levels in the exudate of the wounds were tested. Results showed that seawater immersion aggravated wound injury and that VAC therapy with 180 mmHg negative pressure induced the fastest epidermis migration, obvious edema elimination, significant capillary proliferation, and the highest level of fibronectin, and that in wounds, the proportion of Gram-negative bacteria tended to decrease and that of Gram-positive bacteria tended to increase. Our results show that VAC promotes seawater-immersed wound healing and that 180 mmHg negative pressure may be optimal for wound healing.

  4. Measurement of negative ion mobilities in O2 and O3 mixtures at atmospheric pressure

    International Nuclear Information System (INIS)

    Itoh, H.; Norimoto, K.; Hayashi, T.

    1998-01-01

    Mobility measurements of negative molecular oxygen ions in pure oxygen and in an oxygen-ozone mixture are reported. A cascaded gap consisting of an ion drift gap and an ion detection gap was used in the experiment. The ion detection gap was formed by a positive point and a grounded plane electrode was operated at atmospheric pressure. The zero field mobility of negative molecular oxygen ions was determined to be 2.07+-0.02 cm 2 /V.s. A somewhat higher value of oxygen mobility was found at higher electric field/pressure ratios; this is presumed to be due to negative ozone ions. When changing the electric field/pressure ratio the mobility of negative oxygen ions in oxygen-ozone mixtures becomes smaller than that in pure oxygen; this is probably due to the cumulative effect of other particles produced by silent discharges. (J.U.)

  5. Improved wound management by regulated negative pressure-assisted wound therapy and regulated, oxygen- enriched negative pressure-assisted wound therapy through basic science research and clinical assessment

    OpenAIRE

    Moris Topaz

    2012-01-01

    Regulated negative pressure-assisted wound therapy (RNPT) should be regarded as a state-of-the-art technology in wound treatment and the most important physical, nonpharmaceutical, platform technology developed and applied for wound healing in the last two decades. RNPT systems maintain the treated wound's environment as a semi-closed, semi-isolated system applying external physical stimulations to the wound, leading to biological and biochemical effects, with the potential to substantially i...

  6. A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure.

    Science.gov (United States)

    Chang, Suchi; Shi, Jindong; Fu, Cuiping; Wu, Xu; Li, Shanqun

    2016-01-01

    COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. We evaluated pressure-regulated volume control (PRVC) ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilation - volume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2-4 hours and 48 hours. Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2), and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2) levels. The pH and PaCO2 levels at 2-4 hours were lower and higher, respectively, in the test group than those in the control group (P0.05). Vital signs during 2-4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05). The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2-4 hours and 48 hours was significantly lower than that in the control group (Pvariables were not significantly different between groups (P>0.05). Among elderly COPD patients with respiratory failure, application of PRVC resulted in rapid improvement in arterial blood gas analyses while maintaining a low peak inspiratory pressure. PRVC can reduce pulmonary barotrauma risk, making it a safer protective ventilation mode than synchronized intermittent mandatory ventilation - volume control.

  7. Asymmetric Fuzzy Control of a Positive and Negative Pneumatic Pressure Servo System

    Science.gov (United States)

    Yang, Gang; Du, Jing-Min; Fu, Xiao-Yun; Li, Bao-Ren

    2017-11-01

    The pneumatic pressure control systems have been used in some fields. However, the researches on pneumatic pressure control mainly focus on constant pressure regulation. Poor dynamic characteristics and strong nonlinearity of such systems limit its application in the field of pressure tracking control. In order to meet the demand of generating dynamic pressure signal in the application of the hardware-in-the-loop simulation of aerospace engineering, a positive and negative pneumatic pressure servo system is provided to implement dynamic adjustment of sealed chamber pressure. A mathematical model is established with simulation and experiment being implemented afterwards to discuss the characteristics of the system, which shows serious asymmetry in the process of charging and discharging. Based on the analysis of the system dynamics, a fuzzy proportional integral derivative (PID) controller with asymmetric fuzzy compensator is proposed. Different from conventional adjusting mechanisms employing the error and change in error of the controlled variable as input parameters, the current chamber pressure and charging or discharging state are chosen as inputs of the compensator, which improves adaptability. To verify the effectiveness and performance of the proposed controller, the comparison experiments tracking sinusoidal and square wave commands are conducted. Experimental results show that the proposed controller can obtain better dynamic performance and relatively consistent control performance across the scope of work (2-140 kPa). The research proposes a fuzzy control method to overcome asymmetry and enhance adaptability for the positive and negative pneumatic pressure servo system.

  8. [Closure of cystic cavity-type bedsore by subcutaneous undermining dissection with continuous negative pressure drainage].

    Science.gov (United States)

    Li, Jiang; Guo, Xiao-Ping; Wang, Ke-Hua; Zhao, Dong-Hong; Han, Tong; Lang, Yu-Hong; Peng, Li-Jun

    2012-03-01

    To investigate the clinical effect of subcutaneous undermining dissection with continuous negative pressure drainage for the closure of cystic cavity-type bedsore. 12 patients with cystic cavity-type bedsore underwent surgical debridement and the wounds were closed after subcutaneous undermining dissection. The negative pressure drainage was put in the deep space. The healing process was observed. Completed healing was achieved in all the 12 cases. The skin wounds healed after 17-20 days and the deep spaces closed after 36-43 days. 12 cases were followed up for 1 year with no occurrence. It is an easy and effective method to treat cystic cavity -type bedsore by subcutaneous undermining dissection with continuous negative pressure drainage.

  9. Negative Pressure Pulmonary Edema Following use of Laryngeal Mask Airway (LMA

    Directory of Open Access Journals (Sweden)

    Yesim Bayraktar

    2013-06-01

    Full Text Available Negative pressure pulmonary edema (NPPE following upper airway obstruction is a non-cardiogenic pulmonary edema. The first cause in the etiology of NPPE is developed laryngospasm after intubation or extubation, while the other causes are epiglotitis, croup, hiccups, foreign body aspiration, pharyngeal hematoma and oropharyngeal tumors.The Late diagnosis and treatment causes high morbidity and mortality. The protection of the airway and maintainance of arterial oxygenation will be life saving.In this article we aimed to report  a case of negative pressure pulmonary edema, resolved succesfully after treatment, following use of laryngeal mask airway (LMA.

  10. Perceiving social pressure not to feel negative predicts depressive symptoms in daily life.

    Science.gov (United States)

    Dejonckheere, Egon; Bastian, Brock; Fried, Eiko I; Murphy, Sean C; Kuppens, Peter

    2017-09-01

    Western societies often overemphasize the pursuit of happiness, and regard negative feelings such as sadness or anxiety as maladaptive and unwanted. Despite this emphasis on happiness, the amount of people suffering from depressive complaints is remarkably high. To explain this apparent paradox, we examined whether experiencing social pressure not to feel sad or anxious could in fact contribute to depressive symptoms. A sample of individuals (n = 112) with elevated depression scores (Patient Health Questionnaire [PHQ-9] ≥ 10) took part in an online daily diary study in which they rated their depressive symptoms and perceived social pressure not to feel depressed or anxious for 30 consecutive days. Using multilevel VAR models, we investigated the temporal relation between this perceived social pressure and depressive symptoms to determine directionality. Primary analyses consistently indicated that experiencing social pressure predicts increases in both overall severity scores and most individual symptoms of depression, but not vice versa. A set of secondary analyses, in which we adopted a network perspective on depression, confirmed these findings. Using this approach, centrality analysis revealed that perceived social pressure not to feel negative plays an instigating role in depression, reflected by the high out- and low instrength centrality of this pressure in the various depression networks. Together, these findings indicate how perceived societal norms may contribute to depression, hinting at a possible malignant consequence of society's denouncement of negative emotions. Clinical implications are discussed. © 2017 Wiley Periodicals, Inc.

  11. [Neurogenic intermittent claudication].

    Science.gov (United States)

    Jarmundowicz, W; Haftek, J

    1984-01-01

    In the period 1971-1981 operations were carried out in 1114 cases of discopathy or lumbar spondylosis. Three patients in this group had pains of the type of intermittent claudication as the main symptoms. In all these cases narrowing of the vertebral canal was found in the lumbar part caused in two cases by degenerative changes and herniation of the intervertebral discs, and in a third case it was due to an extensive connective tissue scar at the site of previously done laminectomy. The nerve roots of the cauda were relieved from pressure surgically and in all cases pains disappeared. The authors discuss factors contributing to the development of neurogenic intermittent claudication.

  12. Non-linear Heart Rate and Blood Pressure Interaction in Response to Lower-Body Negative Pressure

    Directory of Open Access Journals (Sweden)

    Ajay K. Verma

    2017-10-01

    Full Text Available Early detection of hemorrhage remains an open problem. In this regard, blood pressure has been an ineffective measure of blood loss due to numerous compensatory mechanisms sustaining arterial blood pressure homeostasis. Here, we investigate the feasibility of causality detection in the heart rate and blood pressure interaction, a closed-loop control system, for early detection of hemorrhage. The hemorrhage was simulated via graded lower-body negative pressure (LBNP from 0 to −40 mmHg. The research hypothesis was that a significant elevation of causal control in the direction of blood pressure to heart rate (i.e., baroreflex response is an early indicator of central hypovolemia. Five minutes of continuous blood pressure and electrocardiogram (ECG signals were acquired simultaneously from young, healthy participants (27 ± 1 years, N = 27 during each LBNP stage, from which heart rate (represented by RR interval, systolic blood pressure (SBP, diastolic blood pressure (DBP, and mean arterial pressure (MAP were derived. The heart rate and blood pressure causal interaction (RR↔SBP and RR↔MAP was studied during the last 3 min of each LBNP stage. At supine rest, the non-baroreflex arm (RR→SBP and RR→MAP showed a significantly (p < 0.001 higher causal drive toward blood pressure regulation compared to the baroreflex arm (SBP→RR and MAP→RR. In response to moderate category hemorrhage (−30 mmHg LBNP, no change was observed in the traditional marker of blood loss i.e., pulse pressure (p = 0.10 along with the RR→SBP (p = 0.76, RR→MAP (p = 0.60, and SBP→RR (p = 0.07 causality compared to the resting stage. Contrarily, a significant elevation in the MAP→RR (p = 0.004 causality was observed. In accordance with our hypothesis, the outcomes of the research underscored the potential of compensatory baroreflex arm (MAP→RR of the heart rate and blood pressure interaction toward differentiating a simulated moderate category hemorrhage from

  13. Negative magnetoresistance of pitch-based carbon fibers Temperature and pressure dependence

    Science.gov (United States)

    Hambourger, P. D.

    1986-01-01

    The negative transverse magnetoresistance of high-modulus pitch-based carbon fibers has been measured over the temperature range 1.3-4.2 K at ambient pressure and at 4.2 K under hydrostatic pressure up to 16 kbar. At low fields (less than 0.5 torr) the magnitude of the magnetoresistance increases markedly as the temperature is lowered from 4.2 K to 1.3 K, in disagreement with Bright's theoretical model, and decreases with pressure at the rate -0.6 percent/kbar.

  14. Topical negative pressure effects on coronary blood flow in a sternal wound model

    DEFF Research Database (Denmark)

    Lindstedt, Sandra; Malmsjö, Malin; Gesslein, Bodil

    2008-01-01

    patients with topical negative pressure (TNP)-treated mediastinitis and CABG patients without mediastinitis. The present study was designed to elucidate if TNP, applied over the myocardium, resulted in an increase of the total amount of coronary blood flow. Six pigs underwent median sternotomy...

  15. Closed incision prophylactic negative pressure wound therapy in patients undergoing major complex abdominal wall repair

    NARCIS (Netherlands)

    de Vries, F. E. E.; Atema, J. J.; Lapid, O.; Obdeijn, M. C.; Boermeester, M. A.

    2017-01-01

    Purpose To evaluate if incisional prophylactic negative pressure wound therapy (pNPWT) reduces wound infections and other wound complications in high-risk patients undergoing major complex ventral abdominal wall repair. Methods Retrospective before-after comparison nested in a consecutive series of

  16. The Application of Negative Pressure Wound Therapy with Installation in Diabetic Foot Associated with Phlegmon.

    Science.gov (United States)

    Wachal, Krzysztof; Szmyt, Krzysztof; Wachal, Magda; Stanisic, Michał

    2015-03-01

    The negative pressure wound therapy in the treatment of diabetic foot ulcers was used successfully for many years. In the case of complications associated with infection by this type of wound treatment to give very good results. From many years of sustained research on a device that could combine the advantages of the negative pressure wound therapy and drainage flow. Finally, in the last year, the first V.A.C. Ulta (KCI, USA) devices were included to the Polish hospital departments. In this paper we present a case of a patient of successfully using a negative pressure wound therapy with installation via a set of V.A.C. Ulta in the ischemic diabetic foot syndrome complicated by phlegmon and tissue necrosis. The patient was treated in stages. In first stage was performed angioplasty of critically stenosis of the superficial femoral artery segment. Secondly, the resection of the necrotic bone revised fingers and forefoot was conducted, and in the third step the negative pressure wound therapy with installation was used. Finally, the wound was closed by the intermediate thickness skin graft. The total duration of treatment was 21 days. The patient in good general condition with a completely healed wound was discharged. Currently, after the supply with orthopedic equipment, patient regained full mobility.

  17. Outcome of Negative-Pressure Wound Therapy for Open Abdomen Treatment After Nontraumatic Lower Gastrointestinal Surgery

    DEFF Research Database (Denmark)

    Bertelsen, Claus Anders; Fabricius, Rasmus; Kleif, Jakob

    2014-01-01

    Few studies have focused on the risk factors for failure to achieve fascial closure after use of negative-pressure wound therapy (NPWT) in an open abdomen (OA). We aimed at analyzing possible risk factors for failure of fascial closure and the risk of fistulas after nontrauma lower gastrointestinal...

  18. A cardiovascular system model for lower-body negative pressure response

    Science.gov (United States)

    Mitchell, B. A., Jr.; Giese, R. P.

    1971-01-01

    Mathematical models used to study complex physiological control systems are discussed. Efforts were made to modify a model of the cardiovascular system for use in studying lower body negative pressure. A computer program was written which allows orderly, straightforward expansion to include exercise, metabolism (thermal stress), respiration, and other body functions.

  19. Using the Solving Problems Together Psychoeducational Group Counseling Model as an Intervention for Negative Peer Pressure

    Science.gov (United States)

    Hall, Kimberly R.; Rushing, Jeri Lynn; Khurshid, Ayesha

    2011-01-01

    Problem-focused interventions are considered to be one of the most effective group counseling strategies with adolescents. This article describes a problem-focused group counseling model, Solving Problems Together (SPT), that focuses on working with students who struggle with negative peer pressure. Adapted from the teaching philosophy of…

  20. A systematic review of topical negative pressure therapy for acute and chronic wounds

    NARCIS (Netherlands)

    Ubbink, D. T.; Westerbos, S. J.; Nelson, E. A.; Vermeulen, H.

    2008-01-01

    Topical negative pressure (TNP) therapy is becoming increasingly popular for all kinds of wounds. Its clinical and cost effectiveness is unclear. A search of randomized controlled trials (RCTs) on TNP in adult patients with all kinds of wounds in all settings was undertaken in Medline, Embase,

  1. NEGATIVE PRESSURE WOUND THERAPY (NPWT FOR THE MANAGEMENT OF DIABETIC FOOT WOUND

    Directory of Open Access Journals (Sweden)

    Wesiana Heris Santy

    2015-11-01

    Full Text Available Complications often experienced by people with diabetes are complications in the feet ( 15 % called diabetic foot ( Akhtyo , 2009 . Where the injury to the leg if not treated properly will lead to infections and ultimately need to be amputated .The purpose of writing articles is to review and discuss the evidence-based literature bersadarkanpraktice of Negative Pressure Wound Therapy Effectiveness ( NPWT on the healing of diabetic foot ulcers.One technology that is used to prevent and avoid lower limb amputation is the technique of negative pressure or Negative Pressure Wound Therapy ( NPWT . This negative pressure technique has grown rapidly and now has been widely used in many countries , especially in Western European countries ( Germany and the United States . Negative pressure technique has the advantage that it is relatively cheaper cost than the use of hyperbaric oxygen . Results obtained by several studies that the use of NPWT may improve wound healing process through efforts to create a moist wound environment and decrease edema that becomes optimal wound healing , throw that out of the wound exudate so that the protease enzyme in the exudate also go wasted , this enzyme is known to interfere wound healing process . The other benefit is that it can stimulate cell growth by increasing angiogenesis physically , so that the growth of new cells will be maximal Abstrak : Komplikasi sering dialami pengidap diabetes adalah komplikasi pada kaki (15% disebut kaki diabetes (Akhtyo, 2009.Dimana luka pada kaki jika tidak ditangani dengan baik akan menyebabkan terjadinya infeksi dan akhirnya perlu di amputasi. Tujuan penulisan artikel adalah mengkaji dan membahas literature bersadarkan evidence based praktice  tentang Efektifitas Negative Pressure Wound Therapy (NPWT pada penyembuhan ulkus kaki Diabetik. Salah satu teknologi yang digunakan untuk mencegah dan menghindari amputasi ekstremitas bawah adalah  teknik tekanan negatif atau Negative

  2. Improved wound management by regulated negative pressure-assisted wound therapy and regulated, oxygen- enriched negative pressure-assisted wound therapy through basic science research and clinical assessment

    Directory of Open Access Journals (Sweden)

    Moris Topaz

    2012-01-01

    Full Text Available Regulated negative pressure-assisted wound therapy (RNPT should be regarded as a state-of-the-art technology in wound treatment and the most important physical, nonpharmaceutical, platform technology developed and applied for wound healing in the last two decades. RNPT systems maintain the treated wound′s environment as a semi-closed, semi-isolated system applying external physical stimulations to the wound, leading to biological and biochemical effects, with the potential to substantially influence wound-host interactions, and when properly applied may enhance wound healing. RNPT is a simple, safe, and affordable tool that can be utilized in a wide range of acute and chronic conditions, with reduced need for complicated surgical procedures, and antibiotic treatment. This technology has been shown to be effective and safe, saving limbs and lives on a global scale. Regulated, oxygen-enriched negative pressure-assisted wound therapy (RO-NPT is an innovative technology, whereby supplemental oxygen is concurrently administered with RNPT for their synergistic effect on treatment and prophylaxis of anaerobic wound infection and promotion of wound healing. Understanding the basic science, modes of operation and the associated risks of these technologies through their fundamental clinical mechanisms is the main objective of this review.

  3. Improved wound management by regulated negative pressure-assisted wound therapy and regulated, oxygen- enriched negative pressure-assisted wound therapy through basic science research and clinical assessment.

    Science.gov (United States)

    Topaz, Moris

    2012-05-01

    Regulated negative pressure-assisted wound therapy (RNPT) should be regarded as a state-of-the-art technology in wound treatment and the most important physical, nonpharmaceutical, platform technology developed and applied for wound healing in the last two decades. RNPT systems maintain the treated wound's environment as a semi-closed, semi-isolated system applying external physical stimulations to the wound, leading to biological and biochemical effects, with the potential to substantially influence wound-host interactions, and when properly applied may enhance wound healing. RNPT is a simple, safe, and affordable tool that can be utilized in a wide range of acute and chronic conditions, with reduced need for complicated surgical procedures, and antibiotic treatment. This technology has been shown to be effective and safe, saving limbs and lives on a global scale. Regulated, oxygen-enriched negative pressure-assisted wound therapy (RO-NPT) is an innovative technology, whereby supplemental oxygen is concurrently administered with RNPT for their synergistic effect on treatment and prophylaxis of anaerobic wound infection and promotion of wound healing. Understanding the basic science, modes of operation and the associated risks of these technologies through their fundamental clinical mechanisms is the main objective of this review.

  4. The use of continuous negative pressure after open debridement for septic arthritis of the shoulder.

    Science.gov (United States)

    Jung, H J; Song, J H; Kekatpure, A L; Adikrishna, A; Hong, H P; Lee, W J; Chun, J M; Jeon, I H

    2016-05-01

    The treatment of septic arthritis of the shoulder is challenging. The infection frequently recurs and the clinical outcome can be very poor. We aimed to review the outcomes following the use of continuous negative pressure after open debridement with a large diameter drain in patients with septic arthritis of the shoulder. A total of 68 consecutive patients with septic arthritis of the shoulder underwent arthrotomy, irrigation and debridement. A small diameter suction drain was placed in the glenohumeral joint and a large diameter drain was placed in the subacromial space with continuous negative pressure of 15 cm H2O. All patients received a standardised protocol of antibiotics for a mean of 5.1 weeks (two to 11.1). Negative pressure was maintained for a mean of 24 days (14 to 32). A total of 67 patients (98.5%) were cured without further treatment being required. At a mean follow-up of 14 months (three to 72), the mean forward flexion was 123° (80° to 140°) and the mean external rotation was 28°(10° to 40°) in those with a rotator cuff tear, and 125° (85° to 145°) and 35° (15° to 45°) in those without a rotator cuff tear. Continuous negative pressure, following open arthrotomy, irrigation and debridement, was effective in treating septic arthritis of the shoulder. The rate of recurrence was significantly lower than with conventional treatment involving arthroscopic or open debridement reported in the literature. Functional outcomes, even in patients with rotator cuff tears, were excellent. Continuous negative pressure is effective in treating septic arthritis of the shoulder. Cite this article: Bone Joint J 2016;98-B:660-5. ©2016 The British Editorial Society of Bone & Joint Surgery.

  5. Novel cavitation fluid jet polishing process based on negative pressure effects.

    Science.gov (United States)

    Chen, Fengjun; Wang, Hui; Tang, Yu; Yin, Shaohui; Huang, Shuai; Zhang, Guanghua

    2018-04-01

    Traditional abrasive fluid jet polishing (FJP) is limited by its high-pressure equipment, unstable material removal rate, and applicability to ultra-smooth surfaces because of the evident air turbulence, fluid expansion, and a large polishing spot in high-pressure FJP. This paper presents a novel cavitation fluid jet polishing (CFJP) method and process based on FJP technology. It can implement high-efficiency polishing on small-scale surfaces in a low-pressure environment. CFJP uses the purposely designed polishing equipment with a sealed chamber, which can generate a cavitation effect in negative pressure environment. Moreover, the collapse of cavitation bubbles can spray out a high-energy microjet and shock wave to enhance the material removal. Its feasibility is verified through researching the flow behavior and the cavitation results of the negative pressure cavitation machining of pure water in reversing suction flow. The mechanism is analyzed through a computational fluid dynamics simulation. Thus, its cavitation and surface removal mechanisms in the vertical CFJP and inclined CFJP are studied. A series of polishing experiments on different materials and polishing parameters are conducted to validate its polishing performance compared with FJP. The maximum removal depth increases, and surface roughness gradually decreases with increasing negative outlet pressures. The surface becomes smooth with the increase of polishing time. The experimental results confirm that the CFJP process can realize a high material removal rate and smooth surface with low energy consumption in the low-pressure environment, together with compatible surface roughness to FJP. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Negative Binomial Fits to Multiplicity Distributions from Central Collisions of (16)O+Cu at 14.6A GeV/c and Intermittency

    Science.gov (United States)

    Tannenbaum, M. J.

    1994-01-01

    The concept of "Intermittency" was introduced by Bialas and Peschanski to try to explain the "large" fluctuations of multiplicity in restricted intervals of rapidity or pseudorapidity. A formalism was proposed to to study non-statistical (more precisely, non-Poisson) fluctuations as a function of the size of rapidity interval, and it was further suggested that the "spikes" in the rapidity fluctuations were evidence of fractal or intermittent behavior, in analogy to turbulence in fluid dynamics which is characterized by self-similar fluctuations at all scales-the absence of well defined scale of length.

  7. A rigid disc for protection of exposed blood vessels during negative pressure wound therapy.

    Science.gov (United States)

    Anesäter, Erik; Borgquist, Ola; Torbrand, Christian; Roupé, K Markus; Ingemansson, Richard; Lindstedt, Sandra; Malmsjö, Malin

    2013-02-01

    There are increasing reports of serious complications and deaths associated with negative pressure wound therapy (NPWT). Bleeding may occur when NPWT is applied to a wound with exposed blood vessels. Inserting a rigid disc in the wound may protect these structures. The authors examined the effects of rigid discs on wound bed tissue pressure and blood flow through a large blood vessel in the wound bed during NPWT. Wounds were created over the femoral artery in the groin of 8 pigs. Rigid discs were inserted. Wound bed pressures and arterial blood flow were measured during NPWT. Pressure transduction to the wound bed was similar for control wounds and wounds with discs. Blood flow through the femoral artery decreased in control wounds. When a disc was inserted, the blood flow was restored. NPWT causes hypoperfusion in the wound bed tissue, presumably as a result of mechanical deformation. The insertion of a rigid barrier alleviates this effect and restores blood flow.

  8. The evidence-based principles of negative pressure wound therapy in trauma & orthopedics.

    Science.gov (United States)

    A, Novak; Khan, Wasim S; J, Palmer

    2014-01-01

    Negative pressure wound therapy is a popular treatment for the management of both acute and chronic wounds. Its use in trauma and orthopedics is diverse and includes the acute traumatic setting as well as chronic troublesome wounds associated with pressure sores and diabetic foot surgery. Efforts have been made to provide an evidence base to guide its use however this has been limited by a lack of good quality evidence. The following review article explores the available evidence and describes future developments for its use in trauma and orthopaedic practice.

  9. The Evidence-Based Principles of Negative Pressure Wound Therapy in Trauma & Orthopedics

    Science.gov (United States)

    A, Novak; Khan, Wasim S; J, Palmer

    2014-01-01

    Negative pressure wound therapy is a popular treatment for the management of both acute and chronic wounds. Its use in trauma and orthopedics is diverse and includes the acute traumatic setting as well as chronic troublesome wounds associated with pressure sores and diabetic foot surgery. Efforts have been made to provide an evidence base to guide its use however this has been limited by a lack of good quality evidence. The following review article explores the available evidence and describes future developments for its use in trauma and orthopaedic practice. PMID:25067971

  10. [Negative Pressure Wound Therapy with Instillation in the Treatment of Critical Wounds].

    Science.gov (United States)

    Gathen, M; Petri, M; Krettek, C; Omar, M

    2016-04-01

    In recent decades, negative pressure wound therapy (NPWT) has become the gold standard in the treatment of infected wounds. Negative pressure wound therapy with instillation (NPWTi) is a new development, that combines conventional NPWT with instillation of fluids. The purpose of this study was to review the results of current literature on the clinical use of NPWTi in acute and chronic wounds. A literature search was performed using Pubmed and the Cochrane Library, including articles in English and German. The data suggest that NPWTi is a promising therapeutic option in the treatment of wounds, and applicable in various fields. NPWTi appears to be a useful adjunct in the treatment of critical wounds. However, data from prospective randomised trials to support the validity of the results are sparse. Georg Thieme Verlag KG Stuttgart · New York.

  11. Silver negative pressure dressing with vacuum-assisted closure of massive pelvic and extremity wounds.

    Science.gov (United States)

    Siegel, Herrick J; Herrera, Diego F; Gay, Jason

    2014-03-01

    Massive soft tissue loss involving the pelvis and extremities from trauma, infections, and tumors remains a challenging and debilitating problem. Although vacuum-assisted closure (VAC) technology is effective in the management of soft tissue loss, the adjunct of a silver dressing in the setting of massive wounds has not been as well tested. Does a silver negative pressure dressing used in conjunction with a wound VAC decrease (1) the length of acute hospital stay and overall length of treatment; (2) the number of surgical débridements the patients underwent as part of their care; and (3) the likelihood of wound closure without soft tissue transposition? We evaluated 42 patients with massive (> 200 cm(2)) pelvic and extremity wounds from trauma, infection, or tumor who were treated with the wound VAC with or without a silver negative pressure dressing between January 2003 and January 2010; the first 26 patients were treated with the wound VAC alone, and in the final 16 consecutively treated patients, the silver dressing was added to the regimen. We reviewed medical records to determine length of treatment as well as the number and type of surgical interventions these patients underwent. We compared the group treated with the wound VAC alone with those patients treated with the wound VAC and silver negative pressure dressing. Hospital stay averaged 19 days in the VAC only group and 7.5 days in the VAC with silver dressing group (p silver dressing group (p silver dressing group (p silver dressing group (p silver negative pressure dressing in combination with the wound VAC as part of routine care of such patients. These results may be used as hypothesis-generating data for future randomized studies. Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

  12. Disagreement in primary study selection between systematic reviews on negative pressure wound therapy

    OpenAIRE

    Peinemann, Frank; McGauran, Natalie; Sauerland, Stefan; Lange, Stefan

    2008-01-01

    Abstract Background Primary study selection between systematic reviews is inconsistent, and reviews on the same topic may reach different conclusions. Our main objective was to compare systematic reviews on negative pressure wound therapy (NPWT) regarding their agreement in primary study selection. Methods This retrospective analysis was conducted within the framework of a systematic review (a full review and a subsequent rapid report) on NPWT prepared by the Institute for Quality and Efficie...

  13. Negative Pressure Wound Therapy in the Management of Combat Wounds: A Critical Review

    OpenAIRE

    Maurya, Sanjay; Bhandari, Prem Singh

    2016-01-01

    Significance: Wounds sustained in a combat trauma often result in a composite tissue loss. Combat injuries, due to high energy transfer to tissues, lead to trauma at multiple anatomical sites. An early wound cover is associated with lower rate of infections and a faster wound healing. The concept of negative pressure wound therapy (NPWT) in the management of combat-related wounds has evolved from the civilian trauma and the wounds from nontraumatic etiologies.

  14. Histomorphological observation of surgical debridement combined with negative pressure therapy in treatment of diabetic foot

    Directory of Open Access Journals (Sweden)

    Jiao-Yun Dong

    2017-08-01

    Conclusion: Epidermal cells on the fascia side of the flap could be derived from the stem cells. Negative pressure wound therapy would attract not only cells but also other elements such as growth factors, cytokines, some nutrients and extracellular matrix. With the formation of the appropriate microenvironment after debridement, the migrated cells can grow, differentiate and spread, eventually leading to the epithelization on the fascia side of the flap in diabetic foot.

  15. Wounds with complicated shapes tend to develop infection during negative pressure wound therapy

    OpenAIRE

    Fujioka, Masaki; Hayashida, Kenji; Senjyu, Chikako

    2014-01-01

    Introduction: While negative pressure wound therapy (NPWP) has been shown to be useful, we felt that patients with wounds of complicated shapes were likely to develop infection during performing NPWT. We conducted an investigation to determine the factors of wound shape responsible for the occurrence of infection. Materials and methods: A total of 55 patients with wounds were treated using NPWT in our unit in 2011. Eight whose wounds formed a pocket, 7 whose wounds were deep, and 40 whose wou...

  16. Silver Negative Pressure Dressing With Vacuum-assisted Closure of Massive Pelvic and Extremity Wounds

    OpenAIRE

    Siegel, Herrick J.; Herrera, Diego F.; Gay, Jason

    2013-01-01

    Background Massive soft tissue loss involving the pelvis and extremities from trauma, infections, and tumors remains a challenging and debilitating problem. Although vacuum-assisted closure (VAC) technology is effective in the management of soft tissue loss, the adjunct of a silver dressing in the setting of massive wounds has not been as well tested. Questions/purposes Does a silver negative pressure dressing used in conjunction with a wound VAC decrease (1) the length of acute hospital stay...

  17. Facets of negative affectivity and blood pressure in middle-aged men

    Directory of Open Access Journals (Sweden)

    Cornel V. Igna

    2013-04-01

    Full Text Available Research results suggesting that facets of negative affectivity, i.e. anxiety, anger-hostility, and depression, relate to incident cardiovascular diseases have been steadily increasing. Evidence for depression has been especially extensive. Elevated blood pressure, a major risk factor of cardiovascular diseases, is one probable mediator in this context. The purpose of this study was to clarify the relationship of specific key elements of depressive disposition, i.e. depressive symptoms, hopelessness and vital exhaustion, with health behavior and blood pressure. Study sample was comprised of 710 middle-aged men. Participants completed self-report questionnaires assessing health behavior, depressive symptoms, vital exhaustion and hopelessness. Statistical analyses involved descriptive analyses, correlations and path analysis. Depressive symptoms and vital exhaustion associated with several unfavorable lifestyles such as smoking, alcohol consumption, and inactivity (standardized solution coefficients: 0.10, 0.14, 0.17, accordingly. However, no significant direct associations with blood pressure could be found for depressive symptoms or vital exhaustion. Hopelessness associated only with unhealthy diet (standardized solution coefficient -0.10 Moreover, for hopelessness, results showed a direct but inverse association with systolic blood pressure (standardized solution coefficient -0.08. Results suggest that the previously reported relations of depression and vital exhaustion with blood pressure could be mediated by unfavorable lifestyles. The relation of hopelessness with adverse health behaviors seems to be less significant. Also, the role of hopelessness as a risk factor of elevated blood pressure is not supported by the results of this study.

  18. Use of negative pressure wound therapy with silver base dressing for necrotizing fasciitis.

    Science.gov (United States)

    Pour, Saman Mohammadi

    2011-01-01

    Necrotizing fasciitis is a life-threatening infection requiring urgent surgical and medical therapy. Hemodynamic stabilization and antimicrobial therapy precede aggressive surgical excision of necrotic tissue, which should be performed as soon as possible. The rapidly spreading infection and aggressive surgical intervention create challenges for wound management. Multiple dressings are available to address the various challenges associated with management of these wounds; this article discusses negative pressure therapy and antimicrobial dressings in the management of Fournier's gangrene, a form of necrotizing fasciitis that involves tissue of the genital or perianal areas. This article reviews the case of a 56-year-old man with fever, tachycardia, and perianal pain associated with necrotizing fasciitis. Extensive surgical debridement was done on the day of admission. After several irrigations, the wound was dressed by negative pressure wound therapy with a silver dressing that minimized hospital stay and enabled early reconstruction. We found that negative pressure wound therapy with a silver-based dressing promoted wound healing and provided a solid matrix for surgical reconstruction.

  19. Infected large pore meshes may be salvaged by topical negative pressure therapy.

    Science.gov (United States)

    Berrevoet, F; Vanlander, A; Sainz-Barriga, M; Rogiers, X; Troisi, R

    2013-02-01

    To evaluate the efficacy of negative pressure therapy for superficial and deep mesh infections after ventral and incisional hernia repair by a prospective monocentric observational study. During a 6-year period, 724 consecutive open ventral and incisional hernia repairs were performed. Pre- and intraoperative data as well as postoperative complications were prospectively recorded. In case of wound infection, negative pressure therapy (NPT) was our primary treatment. Sixty-three patients (8.7 %) were treated using negative pressure therapy after primary ventral and incisional hernia repair. Infectious complications needing NPT occurred in 54 patients in the retromuscular group (54/523; 10.3 %), none when laparoscopically treated and in 9 patients (9/143; 6.3 %) treated by an open intraperitoneal mesh technique. Considering outcome, all meshes were completely salvaged in the retromuscular mesh group after a median of 5 dressing changes (range, 2-9), while in the intraperitoneal mesh, group 3 meshes needed complete (n = 2) or partial (n = 1) excision. Mean duration to complete wound closure was 44 days (range, 26-63 days). NPT is a useful adjunct for salvage of deep infected meshes, particularly when large pore monofilament mesh is used.

  20. Using negative pressure therapy for improving skin graft taking on genital area defects following Fournier gangrene.

    Science.gov (United States)

    Orhan, Erkan; Şenen, Dilek

    2017-09-01

    Fournier's gangrene is an infective necrotizing fasciitis of the perineal, genital and perianal regions. Treatment includes aggressive surgical debridement that often results in extensive loss of genital skin. Skin grafts may be used for reconstruction but skin grafting of the male genitalia is diffucult because the penis and scrotum are mobile and deformable. A variety of methods are used to secure skin graft to recipient beds. We used negative pressure therapy (NPT) to secure skin grafts and improve skin graft taking. We used negative pressure therapy for graft fixation in 13 male patients who underwent debridements with the indication of Fournier gangrene, and whose defects formed were reconstructed with grafts between January 2009, and January 2014. Information about age of the patients, sessions of negative pressure therapy applied before, and after reconstruction, duration of hospital stay, and graft losses during postoperative period were recorded. Median age of the patients was 56.15 (46-72) years. NPT was applied to patients for an average of 6.64 sessions (4-12) before and 1 sessions after graft reconstruction. Patients were hospitalized for an average of 26.7 (20-39) days. Any graft loss was not seen after NPT. Because of the peculiar anatomy of the genital region, anchoring of grafts is difficult so graft losses are often encountered. Use of NPT for ensuring graft fixation on the genital region prevents skin graft shearing.

  1. Irrigation dynamics associated with positive pressure, apical negative pressure and passive ultrasonic irrigations: a computational fluid dynamics analysis.

    Science.gov (United States)

    Chen, José Enrique; Nurbakhsh, Babak; Layton, Gillian; Bussmann, Markus; Kishen, Anil

    2014-08-01

    Complexities in root canal anatomy and surface adherent biofilm structures remain as challenges in endodontic disinfection. The ability of an irrigant to penetrate into the apical region of a canal, along with its interaction with the root canal walls, will aid in endodontic disinfection. The aim of this study was to qualitatively examine the irrigation dynamics of syringe irrigation with different needle tip designs (open-ended and closed-ended), apical negative pressure irrigation with the EndoVac® system, and passive ultrasonic-assisted irrigation, using a computational fluid dynamics model. Syringe-based irrigation with a side-vented needle showed a higher wall shear stress than the open-ended but was localised to a small region of the canal wall. The apical negative pressure mode of irrigation generated the lowest wall shear stress, while the passive-ultrasonic irrigation group showed the highest wall shear stress along with the greatest magnitude of velocity. © 2013 The Authors. Australian Endodontic Journal © 2013 Australian Society of Endodontology.

  2. Cardiovascular regulatory response to lower body negative pressure following blood volume loss

    Science.gov (United States)

    Shimizu, M.; Ghista, D. N.; Sandler, H.

    1979-01-01

    An attempt is made to explain the cardiovascular regulatory responses to lower body negative pressure (LBNP) stress, both in the absence of and following blood or plasma volume loss, the latter being factors regularly observed with short- or long-term recumbency or weightlessness and associated with resulting cardiovascular deconditioning. Analytical expressions are derived for the responses of mean venous pressure and blood volume pooled in the lower body due to LBNP. An analysis is presented for determining the HR change due to LBNP stress following blood volume loss. It is concluded that the reduced orthostatic tolerance following long-term space flight or recumbency can be mainly attributed to blood volume loss, and that the associated cardiovascular responses characterizing this orthostatic intolerance is elicited by the associated central venous pressure response.

  3. Evaluation of negative pressure vacuum-assisted system in acute and chronic wounds closure: our experience.

    Science.gov (United States)

    Chiummariello, S; Guarro, G; Pica, A; Alfano, C

    2012-10-01

    Negative-pressure therapy or vacuum-assisted closure (VAC) has been used in clinical applications since the 1940's and has increased in popularity over the past decade. This dressing technique consists of an open cell foam dressing put into the wound cavity, a vacuum pump produces a negative pressure and an adhesive drape. A controlled sub atmospheric pressure from 75 to 150 mmHg is applied. The vacuum-assisted closure has been applied by many clinicians to chronic wounds in humans; however it cannot be used as a replacement for surgical debridement. The initial treatment for every contaminated wound should be the necrosectomy. The VAC therapy has a complementary function and the range of its indications includes pressure sores, stasis ulcers, chronic wounds such as diabetic foot ulcers, post traumatic and post operative wounds, infected wounds such as necrotizing fasciitis or sternal wounds, soft-tissue injuries, bone exposed injuries, abdominal open wounds and for securing a skin graft. We describe our experience with the VAC dressing used to manage acute and chronic wounds in a series of 135 patients, with excellent results together with satisfaction of the patients.

  4. Benefits at 1 year of nocturnal intermittent positive pressure ventilation in patients with obesity-hypoventi lation syndrome.

    Science.gov (United States)

    de Lucas-Ramos, P; de Miguel-Díez, J; Santacruz-Siminiani, A; González-Moro, J M R; Buendía-García, M J; Izquierdo-Alonso, J L

    2004-10-01

    Patients with the obesity-hypoventilation syndrome (OHS) benefit from non-invasive ventilatory support. We assessed the long-term physiopathological response to 12-months of nocturnal ventilatory assistance at home with bi-level positive airway pressure (BiPAP) via nasal mask in patients with this disease. A series of 13 non-consecutive patients diagnosed of OHS (5 men and 8 women) with a mean (SD) age of 61.9 (8) years, underwent the following studies before (baseline) and after 12 months of non-invasive domiciliary mechanical ventilation: arterial blood gases, nocturnal digital pulse oximetry, spirometry, body plethysmography, maximum muscular respiratory pressures and ventilatory pattern with measurement of occlusion pressure (P0.1) before and after hypercapnia. An overnight cardiorespiratory polygraphy was done at baseline. After 12 months of non-invasive mechanical ventilation, there were significant (P invasive home mechanical ventilation is an effective approach for long-term treatment of OHS.

  5. Intermittency '93

    International Nuclear Information System (INIS)

    Bialas, A.

    1993-01-01

    The existing data definitely indicate the existence of intermittency, i.e. of self similar structures in the systems of particles created in high-energy collisions. The effect seems universal: it was found in most of the processes investigated and its measures parameters depend only weakly (if at all) on the process in question. Strong HBT effect was found, suggesting that intermittency is related to space-time structure of the pion source rather than to detailed momentum structure of the production amplitudes. There are indications that this space time structure may be fractal, but more data is needed to establish this. The theoretical explanation remains obscure: it seems that both parton cascade and hadronization play an important role. Their interrelation, however, remains a mystery. 5 figs., 19 refs

  6. Patients' experiences of negative pressure wound therapy for the treatment of wounds: a review.

    Science.gov (United States)

    Upton, D; Stephens, D; Andrews, A

    2013-01-01

    To review the research on patients' experiences of undergoing negative pressure wound therapy (NPWT). A literature search was carried out using the following databases: Academic Search Complete, CINAHL, PsychINFO, MEDLINE, PubMed and PsyARTICLES. The search covered the period from 2001 to 2012, using the key words: ['negative pressure wound therapy' OR 'vacuum-assisted closure' OR 'topical negative therapy'] AND ['patients' experiences' OR 'psychological' OR 'stress' OR 'anxiety' OR 'wellbeing' OR 'pain' OR 'quality of life' OR 'physical']. Twenty-five relevant articles were included. NPWT is generally considered to be successful in reducing wound depth and facilitating healing. However, studies have highlighted a number of issues that need to be considered. For example, the type of dressing used during treatment can have a significant effect on patients' experience of pain. Furthermore, the NPWT system can cause patients to feel anxious due to both the patient and the health professional being unfamiliar with this form of treatment. It can also restrict patients' daily care and wider social life, which may result in a negative self-image and low self-esteem. Despite this, some studies have reported positive improvements to patients' quality of life. Additionally, since NPWT can lead to faster healing, any detrimental impact upon patients' wellbeing may be short-term and less prolonged than that of other treatments. Compared with other treatments, there is evidence to show that NPWT can lead to faster wound healing, and a reduced frequency of dressing changes and other treatments. However, there are a number of challenges with the use of NPWT, which need to be explored further so that improvements can be made. Specifically, certain aspects of NPWT may impact negatively on patients' wellbeing, albeit short-term. Therefore, research needs to explore patients' experience of NPWT throughout the treatment process and to consider how this can be improved to minimise any

  7. Faster Wound Healing With Topical Negative Pressure Therapy in Difficult-to-Heal Wounds: A Prospective Randomized Controlled Trial

    NARCIS (Netherlands)

    Laat, E.H. de; Boogaard, M.H.W.A. van den; Spauwen, P.H.M.; Kuppevelt, D.H. van; Goor, H. van; Schoonhoven, L.

    2011-01-01

    OBJECTIVE: : A randomized clinical trial was conducted to determine the effectiveness and safety of topical negative pressure therapy in patients with difficult-to-heal wounds. METHODS: : A total of 24 patients were randomly assigned to either treatment with topical negative pressure therapy or

  8. Fate in intermittent claudication

    DEFF Research Database (Denmark)

    Jelnes, Rolf; Gaardsting, O; Hougaard Jensen, K

    1986-01-01

    113 of the patients (44%) had died. Causes of death were no different from those in the general population. Mortality was twice that of the general population matched for age and sex. Mortality among the men was twice that among the women. In men under 60 mortality was four times that expected......, or an ankle/arm pressure index below 50% were individually significantly associated with progression of the arteriosclerotic disease. These findings show the importance of peripheral blood pressure measurements in the management of patients with intermittent claudication due to arteriosclerotic disease....

  9. Severe complications after negative pressure wound therapy in burned wounds: two case reports

    Directory of Open Access Journals (Sweden)

    Ren H

    2014-07-01

    Full Text Available Haitao Ren,1 Yuan Li21Department of Burns and Wound Center, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China; 2Department of Ultrasound, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of ChinaAbstract: We present two typical cases of severe complications (sepsis and hemorrhage after negative pressure wound therapy (NPWT in burned patients. Necrotic tissues in some deep burn wounds are difficult to judge correctly and remove thoroughly. An electrically burned blood vessel looks “intact” but can easily break. Necrotic tissue or injured blood vessels when using NPWT are dangerous, both for causing sepsis and hemorrhage. This is the first article that reports the severe complications of NPWT in burned patients. It is imperative to heed indications and avoid contraindications. Proper preparation of wound beds, close observation, and sufficient irrigation are also crucial to avoid these severe complications, and there is an urgent need to substitute the central vacuum system with the low-pressure system.Keywords: negative pressure wound therapy, complication, burn sepsis, bleeding, drainage

  10. Abdominal compartment syndrome and open abdomen management with negative pressure devices.

    Science.gov (United States)

    Surace, Alessandra; Ferrarese, Alessia; Marola, Silvia; Cumbo, Jacopo; Valentina, Gentile; Borello, Alessandro; Solej, Mario; Martino, Valter; Nano, Mario

    2015-01-01

    Abdominal compartment syndrome (ACS) is defined as an increase of intra-abdominal pressure (IAH) to values higher than 20 mmHg, associated with reduced perfusion and organ dysfunction. There is a classification of open abdomen which stratifies patients according to the natural history of improvement or clinical deterioration. The aim of treatment is to maintain the open abdomen at the lowest level and to prevent progression to a more complex level. Surgical treatment essentially consists in abdominal decompression by leaving the abdomen open. Analysis of the literature shows that negative pressure increases the rate of primary fascial closure; entero-cutaneous fistulas are seen in a minority of cases, without seeming consequence of the application of the dressing. Open abdomen management consists of three treatment stages: acute (24-48 hours), intermediate (from 48 hours to 10 days) and late or reconstruction (from 10 days to the final closure). It's important to recognize patients at risk of IAH and the first signs of ACS and intervene early with abdominal decompression if this will establish itself. Management of the open abdomen is now facilitated by negative pressure devices, which positively affect the morbidity and mortality of patients with ACS.

  11. Sterilization by negative and positive DC plasma with a micro discharge gap at atmospheric pressure

    Science.gov (United States)

    Li, Hua; Jiang, Lin-Xiu; Jiang, Yong-Rong; Zhu, Jian-Min; Chen, Zhen-Cheng

    2017-11-01

    A new needle-to-droplet electrode structure with a micro discharge gap (2 mm) was designed to achieve direct current (DC) discharge plasma in ambient air with the aim of using the plasma to sterilize liquids. Without using noble gases or an external air flow, we succeeded in generating both a negative and positive DC plasma at atmospheric pressure. The plasma was driven by a 0 to ‑20,000 V, 100 W DC power supply. A stainless steel needle with a tip diameter of ˜ 50μm and a 200-μL droplet of bacteria-containing liquid served as the electrodes. At atmospheric pressure and room temperature (23∘C), utilizing the negative DC plasma, the discharge time lasted 10 s; the results showed that the higher the discharge voltage, the more efficient the sterilization effect. Conversely, when we applied a voltage of ‑5.5 kV, we found that the sterilization effect was more efficient for longer discharge times. Our findings demonstrate that Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) can be killed in about 30 s. Our experiments show that our sterilization method required less time and was more efficient for positive than for negative DC plasma under the same conditions.

  12. A randomized, controlled trial of negative pressure wound therapy of pressure ulcers via a novel polyurethane foam.

    Science.gov (United States)

    Wagstaff, Marcus James Dermot; Driver, Sara; Coghlan, Patrick; Greenwood, John Edward

    2014-01-01

    The objectives of the study were (1) to look for any local, clinically apparent response, within and around a debrided wound, to a novel biocompatible polyurethane foam during repeated, short-term implantation, and (2) to assess the material's efficacy as a negative pressure wound therapy (NPWT) interface compared with a widely used, commercially available foam. Twenty pressure ulcers in 18 patients underwent surgical debridement, then randomization to receive novel treatment or control foam as the wound interface for NPWT. Dressing changes every 2-3 days allowed qualitative wound assessment and quantitative measurement to compare outcomes. No adverse reaction was observed in any patient receiving the new foam. The new "novel foam" performed as a NPWT interface as effectively as the control "standard foam." In deep wounds, the new foam was easier to remove, fragmented less, and showed less retention than the control foam. No marginal in-growth occurred, making removal less traumatic and reducing bleeding from cavity wall granulations. The results support previous large animal studies, and independent ISO10993 testing, that the new foam is safe and biocompatible. Its efficacy as an NPWT interface, nontraumatic removal with low fragmentation and retention rate, favors the new material, especially in deep cavity wounds. © 2014 by the Wound Healing Society.

  13. Use of negative pressure wound therapy in the treatment of neonatal and pediatric wounds: a retrospective examination of clinical outcomes.

    Science.gov (United States)

    Baharestani, Mona Mylene

    2007-06-01

    The clinical effectiveness of negative pressure wound therapy for the management of acute and chronic wounds is well documented in the adult population but information regarding its use in the pediatric population is limited. A retrospective, descriptive study was conducted to examine the clinical outcomes of using negative pressure wound therapy in the treatment of pediatric wounds. The medical records of 24 consecutive pediatric patients receiving negative pressure wound therapy were reviewed. Demographic data, wound etiology, time to closure, closure method, duration of negative pressure wound therapy, complications, dressing change frequency, dressing type used, and pressure settings were analyzed. All categorical variables in the dataset were summarized using frequency (count and percentages) and all continuous variables were summarized using median (minimum, maximum). The 24 pediatric patients (mean age 8.5 years [range 14 days to 18 years old]) had 24 wounds - 12 (50%) were infected at baseline. Sixteen patients had hypoalbuminemia and six had exposed hardware and bone in their wounds. Twenty-two wounds reached full closure in a median time of 10 days (range 2 to 45) following negative pressure wound therapy and flap closure (11), split-thickness skin graft (three), secondary (four), and primary (four) closure. Pressures used in this population ranged from 50 to 125 mm Hg and most wounds were covered with reticulated polyurethane foam. One patient developed a fistula during the course of negative pressure wound therapy. When coupled with appropriate systemic antibiotics, surgical debridement, and medical and nutritional optimization, in this population negative pressure wound therapy resulted in rapid granulation tissue and 92% successful wound closure. Future neonatal and pediatric negative pressure wound therapy usage registries and prospective studies are needed to provide a strong evidence base from which treatment decisions can be made in the management

  14. Recent Advances on the Application of Negative Pressure External Volume Expansion in Breast Plastic Surgery.

    Science.gov (United States)

    Liu, Wenyue; Luan, Jie

    2018-02-01

    External volume expansion (EVE) has been effectively applied as an assistance to fat transplantation on breast plastic surgery. Many indicators and refinements have been made in clinical practice; meanwhile, the related mechanism and more optimized preclinical model also have been explored in experimental studies. A literature search was conducted using PubMed with the keywords: EVE, negative pressure, breast enlargement, breast augmentation, breast reconstruction, breast plastic surgery and breast aesthetic surgery. Studies dealing with the clinical and preclinical aspects of the subject and also in vitro experiments related to a certain period of negative pressure and adipose-derived cells were selected, and those only focused on negative pressure were excluded. The indications, contraindications, complications and treatments of EVE in clinical practice were summarized. The experimental studies were mainly classified into two groups (mechanical and translational) according to their contents. Mechanical studies were further divided into inference experimental validation phase studies. For the experimental validation phase, EVE was verified to promote angiogenesis, while it still remained controversial whether it would enhance adipogenesis and cell proliferation. Clinically, our experience is on the stage of exploration, and there is a lack of standardized guidelines on its clinical application. Experimentally, the previous studies showed some subtly different views on the functional mechanisms. However, it is not enough to regulate the clinical practice yet. Therefore, related basic studies and long-term clinical follow-up are needed. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  15. [Asymmetric negative pressure pulmonary edema after acute upper airway obstruction: case report].

    Science.gov (United States)

    Peixoto, Aldo José

    2002-06-01

    Negative pressure pulmonary edema after acute upper airway obstruction is a well-described event, though infrequently diagnosed and reported. This report aimed at presenting a case of upper airway obstruction negative pressure pulmonary edema following acute upper airway obstruction characterized by pulmonary edema asymmetry, being more prominent in the right lung. A 4-year-old boy, 17 kg, phisical status ASA I submitted to combined tonsillectomy, adenoidectomy and turbinate cauterization under general anesthesia with sevoflurane/nitrous oxide/O2. Surgery duration was 90 minutes without complications. During anesthetic recovery and spontaneously breathing, patient reacted to tracheal tube, which was removed. Following, ventilatory efforts resulted in chest wall retraction without apparent air movement, being impossible to ventilate him with facial mask. Symptoms evolved to severe hypoxemia (50% SpO2) requiring reintubation. At this point, it was observed that the lung was stiffer and there were bilateral rales characterizing pulmonary edema. A chest X-ray showed diffuse bilateral infiltrates, right upper lobe atelectasis and marked pulmonary edema asymmetry (right greater than left). Patient was mechanically ventilated with PEEP for 20 hours when he was extubated. There was a progressive pulmonary edema improvement and patient was discharged 48 hours later. Negative pressure pulmonary edema (NPPE) is a rare event with high morbidity risk. It is often not diagnosed and requires from the anesthesiologist an updated knowledge and adequate management. It is usually bilateral, rarely unilateral, and exceptionally asymmetric as in this case. Most cases are treated by mechanical ventilation with PEEP or CPAP without any other therapy. The prognosis is favorable, with most cases recovering within the first 24 hours.

  16. Flame Atmospheric Pressure Chemical Ionization Coupled with Negative Electrospray Ionization Mass Spectrometry for Ion Molecule Reactions

    Science.gov (United States)

    Cheng, Sy-Chyi; Bhat, Suhail Muzaffar; Shiea, Jentaie

    2017-07-01

    Flame atmospheric pressure chemical ionization (FAPCI) combined with negative electrospray ionization (ESI) mass spectrometry was developed to detect the ion/molecule reactions (IMRs) products between nitric acid (HNO3) and negatively charged amino acid, angiotensin I (AI) and angiotensin II (AII), and insulin ions. Nitrate and HNO3-nitrate ions were detected in the oxyacetylene flame, suggesting that a large quantity of nitric acid (HNO3) was produced in the flame. The HNO3 and negatively charged analyte ions produced by a negative ESI source were delivered into each arm of a Y-shaped stainless steel tube where they merged and reacted. The products were subsequently characterized with an ion trap mass analyzer attached to the exit of the Y-tube. HNO3 showed the strongest affinity to histidine and formed (Mhistidine-H+HNO3)- complex ions, whereas some amino acids did not react with HNO3 at all. Reactions between HNO3 and histidine residues in AI and AII resulted in the formation of dominant [MAI-H+(HNO3)]- and [MAII-H+(HNO3)]- ions. Results from analyses of AAs and insulin indicated that HNO3 could not only react with basic amino acid residues, but also with disulfide bonds to form [M-3H+(HNO3)n]3- complex ions. This approach is useful for obtaining information about the number of basic amino acid residues and disulfide bonds in peptides and proteins.

  17. Flame Atmospheric Pressure Chemical Ionization Coupled with Negative Electrospray Ionization Mass Spectrometry for Ion Molecule Reactions.

    Science.gov (United States)

    Cheng, Sy-Chyi; Bhat, Suhail Muzaffar; Shiea, Jentaie

    2017-07-01

    Flame atmospheric pressure chemical ionization (FAPCI) combined with negative electrospray ionization (ESI) mass spectrometry was developed to detect the ion/molecule reactions (IMRs) products between nitric acid (HNO 3 ) and negatively charged amino acid, angiotensin I (AI) and angiotensin II (AII), and insulin ions. Nitrate and HNO 3 -nitrate ions were detected in the oxyacetylene flame, suggesting that a large quantity of nitric acid (HNO 3 ) was produced in the flame. The HNO 3 and negatively charged analyte ions produced by a negative ESI source were delivered into each arm of a Y-shaped stainless steel tube where they merged and reacted. The products were subsequently characterized with an ion trap mass analyzer attached to the exit of the Y-tube. HNO 3 showed the strongest affinity to histidine and formed (M histidine -H+HNO 3 ) - complex ions, whereas some amino acids did not react with HNO 3 at all. Reactions between HNO 3 and histidine residues in AI and AII resulted in the formation of dominant [M AI -H+(HNO 3 )] - and [M AII -H+(HNO 3 )] - ions. Results from analyses of AAs and insulin indicated that HNO 3 could not only react with basic amino acid residues, but also with disulfide bonds to form [M-3H+(HNO 3 ) n ] 3- complex ions. This approach is useful for obtaining information about the number of basic amino acid residues and disulfide bonds in peptides and proteins. Graphical Abstract ᅟ.

  18. Intermittent hyperthyreosis

    International Nuclear Information System (INIS)

    Sulman, F.G.; Tal, E.; Pfeifer, Y.; Superstine, E.

    1975-01-01

    Intermittent hyperthyreosis occurs under various forms of stress, especially heat stress. The clinician may diagnose such cases as masked or apathetic hyperthyroidism or 'forme fruste' hyperthyreosis or thyroid autonomy. As most routine and standard tests may here yield inconsistent results, it is the patients' anamnesis which may provide the clue. Our Bioclimatology Unit has now seen over 100 cases in which thyroid hypersensitivity towards heat was the most prominent syndrome: 10-15% of weather-sensitive patients are affected. The patients complain before or during heat spells of such contradictory symptoms as insomnia, irritability, tension, tachycardia, palpitations, precordial pain, dyspnoe, flushes with sweating or chills, tremor, abdominal pain or diarrhea, polyuria or pollakisuria, weight loss in spite of ravenous appetite, fatigue, exhaustion, depression, adynamia, lack of concentration and confusion. Determination of urinary neurohormones allows a differential diagnosis, intermittent hyperthyreosis being characterized by three cardinal symptoms: tachycardia - every case with more than 80 pulse beats being suspect (not specific); urinary histamine - every case excreting more than 90 μg/day being suspect. Again the drawback of this test is its lack of specificity, as histamine may also be increased in cases of allergy and spondylitis; urinary thyroxine - every case excreting more than 20 μg/day T-4 being suspect. This is the only specific test. Therapy should make use of lithium carbonate and betablockers. Propyl thiouracil is rarely required. (orig.) [de

  19. An Alternative Treatment Strategy for Complicated Chronic Wounds: Negative Pressure Therapy over Mesh Skin Graft

    Directory of Open Access Journals (Sweden)

    Michele Maruccia

    2017-01-01

    Full Text Available Extensive skin defect represents a real problem and major challenge in plastic and reconstructive surgery. On one hand, skin grafts offer a practical method to deal with skin defects despite their unsuitability for several complicated wounds. On the other hand, negative pressure wound therapy (NPWT, applied before skin grafting, promotes granulation tissue growth. The aim of the study is to evaluate the improvement in wound healing given by the merger of these two different approaches. We treated 23 patients for large wounds of multiple factors. Of these, 15 were treated with the application of V.A.C.® Therapy (KCI Medical S.r.l., Milan, Italy, in combination with skin grafts after a prior unsuccessful treatment of 4 weeks with mesh skin grafts and dressings. Another 8 were treated with only mesh skin graft. Pain reduction and wound area reduction were found statistically significant (p<0.0009, p<0.0001. Infection was resolved in almost all patients. According to our study, the use of the negative pressure wound therapy over mesh skin grafts is significantly effective especially in wounds resistant to conventional therapies, thereby improving the rate of skin graft take.

  20. Effect of hindlimb suspension on cardiovascular responses to sympathomimetics and lower body negative pressure

    Science.gov (United States)

    Overton, J. Michael; Tipton, Charles M.

    1990-01-01

    To determine whether hindlimb suspension is associated with the development of cardiovascular deconditioning, male rats were studied before and after undergoing one of three treatment conditions for 9 days: (1) cage control (n = 15, CON), (2) horizontal suspension (n = 15, HOZ), and (3) head-down suspension (n = 18, HDS). Testing included lower body negative pressure administered during chloralose-urethan anesthesia and graded doses of sympathomimetic agents (norepinephrine, phenylephrine, and tyramine) administered to conscious unrestrained animals. Both HDS and HOZ were associated with a small decrease in the hypotensive response to lower body negative pressure. The HOZ group, but not the HDS group, exhibited augmented reflex tachycardia. Furthermore, both HDS and HOZ groups manifested reduced pressor responses to phenylephrine after treatment. These reductions were associated with significantly attenuated increases in mesenteric vascular resistance. However, baroreflex control of heart rate was not altered by the treatment conditions. Collectively, these results indicate that 9 days of HDS in rats does not elicit hemodynamic response patterns generally associated with cardiovascular deconditioning induced by hypogravic conditions.

  1. Matching Biological Mesh and Negative Pressure Wound Therapy in Reconstructing an Open Abdomen Defect

    Directory of Open Access Journals (Sweden)

    Fabio Caviggioli

    2014-01-01

    Full Text Available Reconstruction of open abdominal defects is a clinical problem which general and plastic surgeons have to address in cooperation. We report the case of a 66-year-old man who presented an abdominal dehiscence after multiple laparotomies for a sigmoid-rectal adenocarcinoma that infiltrated into the abdominal wall, subsequently complicated by peritonitis and enteric fistula. A cutaneous dehiscence and an incontinent abdominal wall resulted after the last surgery. The abdominal wall was reconstructed using a biological porcine cross-linked mesh Permacol (Covidien Inc., Norwalk, CT. Negative Pressure Wound Therapy (NPWT, instead, was used on the mesh in order to reduce wound dimensions, promote granulation tissue formation, and obtain secondary closure of cutaneous dehiscence which was finally achieved with a split-thickness skin graft. Biological mesh behaved like a scaffold for the granulation tissue that was stimulated by the negative pressure. The biological mesh was rapidly integrated in the abdominal wall restoring abdominal wall continence, while the small dehiscence, still present in the central area, was subsequently covered with a split-thickness skin graft. The combination of these different procedures led us to solve this complicated case obtaining complete wound closure after less than 2 months.

  2. Negative pressure wound therapy for serious dog bites of extremities: a prospective randomized trial.

    Science.gov (United States)

    Rui-Feng, Chen; Li-Song, Huang; Ji-Bo, Zheng; Yi-Qing, Jia; Yu-Jie, Liu; Yi, Shan

    2016-06-01

    The objectives were to investigate the emergency treatment of serious dog bite lacerations on limbs and to identify whether negative pressure wound therapy (NPWT) was beneficial in these instances. A total of 580 cases with serious limb lacerations due to dog bites were randomly divided into 2 groups. After thorough debridement, the limb lacerations of group A (n = 329) were left open. The remaining cases (n = 251) were randomly divided into 2 subgroups, group B and group C, which were treated with 125 and 75 mm Hg of continuous negative pressure, respectively. Antibiotics were only used in cases where there were systemic signs of wound infection, and were not given prophylactically. The infection rate, infection time, and healing time were analyzed. The wound infection rates of groups A, B, and C were 9.1%, 4.1%, and 3.9%, respectively. The infection times of the 3 groups were 26.3 ± 11.6, 159.8 ± 13.4, and 166.4 ± 16.2 hours, respectively. The recovery times of the infection patients in the 3 groups were 19.2 ± 4.6, 13.2 ± 2.1, and 12.7 ± 2.3 days, respectively, and in the noninfection patients, the recovery times were 15.6 ± 2.7, 10.1 ± 2.3, and 10.5 ± 1.9 days, respectively. In groups B (-125 mm Hg) and C (-75 mm Hg), the infection rate, infection time, and healing time showed no significant differences. Patients with serious dog bite laceration on limbs could benefit from NPWT. Compared with the traditional treatment of leaving the wounds open, NPWT reduced the infection rate and shortened recovery time. When NPWT was performed, low negative pressure (-75 mm Hg) had the same positive effects as high pressure (-125 mm Hg). Prophylactic antibiotics administration is not recommended for treating this kind of laceration. Therapeutic/care management, level II. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Negative Pressure Wound Therapy With Instillation: Review of Evidence and Recommendations.

    Science.gov (United States)

    Kim, Paul J; Attinger, Christopher E; Olawoye, Olayinka; Crist, Brett D; Gabriel, Allen; Galiano, Robert D; Gupta, Subhas; Lantis Ii, John C; Lavery, Lawrence; Lipsky, Benjamin A; Teot, Luc

    2015-12-01

    Negative pressure wound therapy with instillation (NPWTi) and dwell time is an adjunctive treatment modality for selected complex wounds. Because of the greater amount of research now available, a multidisciplinary expert panel comprising the fields of podiatry, plastic and general surgery, burn treatment, infectious diseases, and orthopedics was convened on July 11, 2015, to produce a summary of the data and recommendations on the use of NPWTi. The panel members each reviewed available published literature on NPWTi in the PubMed, Cochrane, and Google Scholar databases from 1 January 2012 up until 20 July 2015 using the string search term negative pressure wound therapy instillation provided by the panel moderator; there were no restrictions on the language or type of publication. Panel members discussed their experiences and worked to reach consensus on several predefined topics. NPWTi was found to be most appropriate for properly selected complex hosts or wounds such as patients with multiple comorbidities, patients with an American Society of Anesthesiology Classification ≥ 2, severe traumatic wounds, diabetic foot infections, and wounds complicated by invasive infection or extensive biofilm. NPWTi should not be used routinely to treat simple wounds or hosts without comorbidities.There is evidence that when NPWTi is added to standard of care in properly selected cases it provides better overall clinical outcomes than standard of care alone, even when including NPWT. Based on published evidence and panel member experience, the Panel recommends a dwell time - fluid briefly instilled into the wound and allowed to diffuse for a user-specified time - of 10-20 minutes followed by 2-4 hours of negative pressure at -125 mmHg, although larger wounds may need times of up to 6 hours. Normal saline (0.9%) is the preferred solution for NPWTi, except in special situations. NPWTi with dwell time is an adjunct to other standard principles of appropriate wound assessment and

  4. Increase in vagal activity during hypotensive lower-body negative pressure in humans

    DEFF Research Database (Denmark)

    Sander-Jensen, K; Mehlsen, J; Stadeager, C

    1988-01-01

    Progressive central hypovolemia is characterized by a normotensive, tachycardic stage followed by a reversible, hypotensive stage with slowing of the heart rate (HR). We investigated circulatory changes and arterial hormone concentrations in response to lower-body negative pressure (LBNP) in six...... volunteers before and after atropine administration. LBNP of 55 mmHg initially resulted in an increase in HR from 55 +/- 4 to 90 +/- 5 beats/min and decreases in mean arterial pressure (MAP) from 94 +/- 4 to 81 +/- 5 mmHg, in central venous pressure from 7 +/- 1 to -3 +/- 1 mmHg, and in cardiac output from 6.......1 +/- 0.5 to 3.7 +/- 0.11/min. Concomitantly, epinephrine and norepinephrine levels increased. After 8.2 +/- 2.3 min of LBNP, the MAP had decreased to 41 +/- 7 mmHg and HR had decreased to 57 +/- 3 beats/min. Vasopressin increased from 1.2 +/- 0.3 to 137 +/- 45 pg/ml and renin activity increased from 1...

  5. Validation of lower body negative pressure as an experimental model of hemorrhage

    Science.gov (United States)

    Shade, Robert E.; Muniz, Gary W.; Bauer, Cassondra; Goei, Kathleen A.; Pidcoke, Heather F.; Chung, Kevin K.; Cap, Andrew P.; Convertino, Victor A.

    2013-01-01

    Lower body negative pressure (LBNP), a model of hemorrhage (Hem), shifts blood to the legs and elicits central hypovolemia. This study compared responses to LBNP and actual Hem in sedated baboons. Arterial pressure, pulse pressure (PP), central venous pressure (CVP), heart rate, stroke volume (SV), and +dP/dt were measured. Hem steps were 6.25%, 12.5%, 18.75%, and 25% of total estimated blood volume. Shed blood was returned, and 4 wk after Hem, the same animals were subjected to four LBNP levels which elicited equivalent changes in PP and CVP observed during Hem. Blood gases, hematocrit (Hct), hemoglobin (Hb), plasma renin activity (PRA), vasopressin (AVP), epinephrine (EPI), and norepinephrine (NE) were measured at baseline and maximum Hem or LBNP. LBNP levels matched with 6.25%, 12.5%, 18.75%, and 25% hemorrhage were −22 ± 6, −41 ± 7, −54 ± 10, and −71 ± 7 mmHg, respectively (mean ± SD). Hemodynamic responses to Hem and LBNP were similar. SV decreased linearly such that 25% Hem and matching LBNP caused a 50% reduction in SV. Hem caused a decrease in Hct, Hb, and central venous oxygen saturation (ScvO2). In contrast, LBNP increased Hct and Hb, while ScvO2 remained unchanged. Hem caused greater elevations in AVP and NE than LBNP, while PRA, EPI, and other hematologic indexes did not differ between studies. These results indicate that while LBNP does not elicit the same effect on blood cell loss as Hem, LBNP mimics the integrative cardiovascular response to Hem, and validates the use of LBNP as an experimental model of central hypovolemia associated with Hem. PMID:24356525

  6. Cardiovascular response to lower body negative pressure stimulation before, during, and after space flight

    Science.gov (United States)

    Baisch, F.; Beck, L.; Blomqvist, G.; Wolfram, G.; Drescher, J.; Rome, J. L.; Drummer, C.

    2000-01-01

    BACKGROUND: It is well known that space travel cause post-flight orthostatic hypotension and it was assumed that autonomic cardiovascular control deteriorates in space. Lower body negative pressure (LBNP) was used to assess autonomic function of the cardiovascular system. METHODS: LBNP tests were performed on six crew-members before and on the first days post-flight in a series of three space missions. Additionally, two of the subjects performed LBNP tests in-flight. LBNP mimics fluid distribution of upright posture in a gravity independent way. It causes an artificial sequestration of blood, reduces preload, and filtrates plasma into the lower part of the body. Fluid distribution was assessed by bioelectrical impedance and anthropometric measurements. RESULTS: Heart rate, blood pressure, and total peripheral resistance increased significantly during LBNP experiments in-flight. The decrease in stroke volume, the increased pooling of blood, and the increased filtration of plasma into the lower limbs during LBNP indicated that a plasma volume reduction and a deficit of the interstitial volume of lower limbs rather than a change in cardiovascular control was responsible for the in-flight response. Post-flight LBNP showed no signs of cardiovascular deterioration. The still more pronounced haemodynamic changes during LBNP reflected the expected behaviour of cardiovascular control faced with less intravascular volume. In-flight, the status of an intra-and extravascular fluid deficit increases sympathetic activity, the release of vasoactive substances and consequently blood pressure. Post-flight, blood pressure decreases significantly below pre-flight values after restoration of volume deficits. CONCLUSION: We conclude that the cardiovascular changes in-flight are a consequence of a fluid deficit rather than a consequence of changes in autonomic signal processing.

  7. Efficacy and safety of negative pressure wound therapy for Szilagyi grade III peripheral vascular graft infection.

    Science.gov (United States)

    Cheng, Hsu-Tang; Hsu, Yung-Chang; Wu, Chao-I

    2014-12-01

    A best evidence topic in vascular surgery was written according to a structured protocol. The question addressed was whether it is safe and effective to use negative pressure wound therapy (NPWT) for Szilagyi grade III (i.e. the arterial implant proper involved in the infection) peripheral vascular graft infection. Altogether, 69 papers were found using the reported search. From the search results, reference lists of potentially eligible studies and related citations in PubMed, seven papers represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. In the only randomized, controlled trial that compared NPWT (n = 10) and alginate dressing change (n = 10), the NPWT group demonstrated shorter time to full skin epithelialization (median 57 vs 104 days; P = 0.026). In the other six case series, the recruited case number ranged from 12 to 72. The mode of NPWT varied among the included studies, with the majority using a continuous negative pressure of 125 mmHg. One study combined NPWT and sartorius myoplasty, another used sartorius myoplasty in selected cases and others did not. The mean duration of using NPWT ranged from 14.2 to 43 days. The mean duration to achieve complete wound healing ranged from 24 (the study with sartorius myoplasty) to 51 days. The NPWT treatment failure rate ranged from 0 (the study with sartorius myoplasty) to 25%. The major complication of NPWT was bleeding and the incidence rate was reported to be 1 year of follow-up) showed that NPWT with a continuous negative pressure of 125 mmHg, or combined NPWT and sartorius myoplasty, may shorten the time to complete wound healing by 2 months, have a >70% success rate, and have a <10% NPWT-related complication rate. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights

  8. Historical Review of Lower Body Negative Pressure Research in Space Medicine.

    Science.gov (United States)

    Campbell, Mark R; Charles, John B

    2015-07-01

    Cephalad redistribution of intravascular and extravascular fluid occurs as a result of weightlessness during spaceflight. This provokes cardiovascular, cardiopulmonary, and autonomic nervous system responses. The resulting altered functional state can result in orthostatic hypotension and intolerance upon landing and return to a gravity environment. In-flight lower body negative pressure (LBNP) transiently restores normal body fluid distribution. Early in the U.S. space program, LBNP was devised as a way to test for orthostatic intolerance. With the development of the Skylab Program and longer duration spaceflight, it was realized that it could provide a method of monitoring orthostatic intolerance in flight and predicting the post-landing orthostatic response. LBNP was also investigated not only as an in-flight cardiovascular orthostatic stress test, but also as a countermeasure to cardiovascular deconditioning on Soviet space stations, Skylab, and the Shuttle. It is still being used by the Russian program on the International Space Station as an end-of-flight countermeasure.

  9. Effects of regional hemoconcentration during LBNP on plasma volume determinations. [Lower Body Negative Pressure

    Science.gov (United States)

    Loeppky, J. A.; Kobayashi, Y.; Venters, M. D.; Luft, U. C.

    1979-01-01

    Blood samples were obtained from forearm vein or artery with indwelling cannula (1) before, (2) during the last min, and (3) about 2 min after lower body negative pressure (LBNP) in 16 experiments to determine whether plasma volume (PV) estimates were affected by regional hemoconcentration in the lower body. Total hemoglobin (THb) was estimated with the CO method prior to LBNP. Hemoglobin (Hb) and hematocrit (Hct) values from (2) gave only a 3% (87 ml) loss in PV due to LBNP, assuming no change in THb. However, Hb and Hct values from (3) showed an 11% loss in PV (313 ml). This 72% underestimation of PV loss with (2) must have resulted from the sequestration of blood and subsequent hemoconcentration in the lower body during LBNP. The effects of LBNP on PV should be estimated 1-3 min after exposure, after mixing but before extravascular fluid returns to the circulation.

  10. Negative pressure wound therapy in pediatric surgery: How and when to use.

    Science.gov (United States)

    de Jesus, Lisieux Eyer; Martins, Alana Bandeira; Oliveira, Pablo Baptista; Gomes, Fernanda; Leve, Thais; Dekermacher, Samuel

    2018-04-01

    Negative pressure wound therapy (NPWT) has been widely adopted to treat laparostomy, abdominal compartment syndrome (ACS) and complicated wounds associated with tissue loss. The method presents specific aspects, advantages and indications in Pediatrics. Our aim is to review the evidence available about NPWT in children. Active search for papers about NPWT in Pediatric patients. Papers referring to orthopedic problems, wound complications after Cardiac Surgery or burns were excluded. The method shows good results to treat ACS, complicated wounds and abdominal wall malformations in neonates, including prematures. Periwound skin protection, monitoring of fluid losses and fine tuning of negative pressure levels according to age are necessary. Less pain, quicker recovery, less frequent dressing changes, possible recovery of exposed surgical hardware, granulation and shrinkage of the wound are advantages of the method over other kinds of dressing. NPWT is contraindicated over blood vessels and exposed nerves. Debridement is needed before usage over necrotic areas. Enteric fistulae are not contraindications. Complications are rare, mainly foam retention and dermatitis/skin maceration. The possibility of fistulae being caused by NPWT remains debatable. NPWT is widely used in Pediatrics, including neonates and premature, but the evidence available about the method is scarce and low quality. Complications are uncommon and mostly manageable. A possible causal relationship between NPWY and enteric fistula remains unclear. Adult devices and parameters have been adapted to children's use. Extra care is needed to protect the delicate tissues of Pediatric patients. Comparative research to define differential costs, indications and advantages of the method, specific indications and limits of NWTP in Pediatrics is needed. Review. IV. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Intrarectal negative pressure system in the management of open abdomen with colorectal fistula: A case report☆

    Science.gov (United States)

    Yetişir, Fahri; Salman, A. Ebru; Mamedov, Ruslan; Aksoy, Mustafa; Yalcin, Abdussamet; Kayaalp, Cüneyt

    2014-01-01

    INTRODUCTION To present the management of open abdomen with colorectal fistula by application of intrarectal negative pressure system (NPS) in addition to abdominal NPS. PRESENTATION OF CASE Twenty-year old man had a history of injuries by a close-range gunshot to the abdomen eight days ago and he had been treated by bowel repairs, resections, jejunal anastomosis and Hartman's procedure. He was referred to our center after deterioration, evisceration with open abdomen and enteric fistula in septic shock. There were edematous, fibrinous bowels and large multiple fistulas from the edematous rectal stump. APACHE II, Mannheim Peritoneal Index and Björck scores were 18, 33 and 3, respectively (expected mortality 100%). After intensive care for 5 days, he was treated by abdominal and intrarectal NPS. NPS repeated for 5 times and the fistula was recovered on day 18 completely. Fascial closure was facilitated with a dynamic abdominal closure system (ABRA) and he was discharged on day 33 uneventfully. There was no herniation and any other problem after 12 months follow-up. DISCUSSION Management of fistula in OA can be extremely challenging. Floating stoma, fistula VAC, nipple VAC, ring and silo VAC, fistula intubation systems are used for isolation of the enteric effluent from OA. Several biologic dressings such as acellular dermal matrix, pedicled flaps have been used to seal the fistula opening with various success. Resection of the involved enteric loop and a new anastomosis of the intestine is very hard and rarely possible. In all of these reports, usually patients are left to heal with a giant hernia. In contrast to this, there is no hernia in our case during one year follow up period. CONCLUSION Combination of intra and extra luminal negative pressure systems and ABRA is a safe and successful method to manage open abdomen with colorectal fistula. PMID:24584042

  12. Intrarectal negative pressure system in the management of open abdomen with colorectal fistula: A case report.

    Science.gov (United States)

    Yetişir, Fahri; Salman, A Ebru; Mamedov, Ruslan; Aksoy, Mustafa; Yalcin, Abdussamet; Kayaalp, Cüneyt

    2014-01-01

    To present the management of open abdomen with colorectal fistula by application of intrarectal negative pressure system (NPS) in addition to abdominal NPS. Twenty-year old man had a history of injuries by a close-range gunshot to the abdomen eight days ago and he had been treated by bowel repairs, resections, jejunal anastomosis and Hartman's procedure. He was referred to our center after deterioration, evisceration with open abdomen and enteric fistula in septic shock. There were edematous, fibrinous bowels and large multiple fistulas from the edematous rectal stump. APACHE II, Mannheim Peritoneal Index and Björck scores were 18, 33 and 3, respectively (expected mortality 100%). After intensive care for 5 days, he was treated by abdominal and intrarectal NPS. NPS repeated for 5 times and the fistula was recovered on day 18 completely. Fascial closure was facilitated with a dynamic abdominal closure system (ABRA) and he was discharged on day 33 uneventfully. There was no herniation and any other problem after 12 months follow-up. Management of fistula in OA can be extremely challenging. Floating stoma, fistula VAC, nipple VAC, ring and silo VAC, fistula intubation systems are used for isolation of the enteric effluent from OA. Several biologic dressings such as acellular dermal matrix, pedicled flaps have been used to seal the fistula opening with various success. Resection of the involved enteric loop and a new anastomosis of the intestine is very hard and rarely possible. In all of these reports, usually patients are left to heal with a giant hernia. In contrast to this, there is no hernia in our case during one year follow up period. Combination of intra and extra luminal negative pressure systems and ABRA is a safe and successful method to manage open abdomen with colorectal fistula. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Analysis of Effective Interconnectivity of DegraPol-foams Designed for Negative Pressure Wound Therapy

    Directory of Open Access Journals (Sweden)

    Heike Hall

    2009-03-01

    Full Text Available Many wounds heal slowly and are difficult to manage. Therefore Negative Pressure Wound Therapy (NPWT was developed where polymer foams are applied and a defined negative pressure removes wound fluid, reduces bacterial burden and increases the formation of granulation tissue. Although NPWT is used successfully, its mechanisms are not well understood. In particular, different NPWT dressings were never compared. Here a poly-ester urethane Degrapol® (DP-foam was produced and compared with commercially available dressings (polyurethane-based and polyvinyl-alcohol-based in terms of apparent pore sizes, swelling and effective interconnectivity of foam pores. DP-foams contain relatively small interconnected pores; PU-foams showed large pore size and interconnectivity; whereas PVA-foams displayed heterogeneous and poorly interconnected pores. PVA-foams swelled by 40 %, whereas DP- and PU-foams remained almost without swelling. Effective interconnectivity was investigated by submitting fluorescent beads of 3, 20 and 45 mm diameter through the foams. DP- and PU-foams removed 70-90 % of all beads within 4 h, independent of the bead diameter or bead pre-adsorption with serum albumin. For PVA-foams albumin pre-adsorbed beads circulated longer, where 20 % of 3 mm and 10 % of 20 mm diameter beads circulated after 96 h. The studies indicate that efficient bead perfusion does not only depend on pore size and swelling capacity, but effective interconnectivity might also depend on chemical composition of the foam itself. In addition due to the efficient sieve-effect of the foams uptake of wound components in vivo might occur only for short time suggesting other mechanisms being decisive for success of NPWT.

  14. Fluid Shifts: Otoacoustical Emission Changes in Response to Posture and Lower Body Negative Pressure

    Science.gov (United States)

    Melgoza, R.; Kemp, D.; Ebert, D.; Danielson, R.; Stenger, M.; Hargens, A.; Dulchavsky, S.

    2016-01-01

    INTRODUCTION: The purpose of the NASA Fluid Shifts Study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight and to correlate these findings with vision changes and other elements of the visual impairment and intracranial pressure (VIIP) syndrome. VIIP signs and symptoms, as well as postflight lumbar puncture data, suggest that elevated intracranial pressure (ICP) may be associated with spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. Due to the invasive nature of direct measures of ICP, a noninvasive technique of monitoring ICP is desired for use during spaceflight. The phase angle and amplitude of otoacoustic emissions (OAEs) have been shown to be sensitive to posture change and ICP (1, 2), therefore use of OAEs is an attractive option. OAEs are low-level sounds produced by the sensory cells of the cochlea in response to auditory stimulation. These sounds travel peripherally from the cochlea, through the oval window, to the ear canal where they can be recorded. OAE transmission is sensitive to changes in the stiffness of the oval window, occurring as a result of changes in cochlear pressure. Increased stiffness of the oval window largely affects the transmission of sound from the cochlea at frequencies between 800 Hz and 1600 Hz. OAEs can be self-recorded in the laboratory or on the ISS using a handheld device. Our primary objectives regarding OAE measures in this experiment were to 1) validate this method during preflight testing of each crewmember (while sitting, supine and in head-down tilt position), and 2) determine if OAE measures (and presumably ICP) are responsive to lower body negative pressure and to spaceflight. METHODS: Distortion-product otoacoustic emissions (DPOAEs) and transient evoked otoacoustic emissions (TEOAEs) were recorded preflight using the Otoport Advance OAE system (Otodynamics Ltd., Hatfield, UK). Data were collected in four conditions (seated

  15. Development of micropump-actuated negative pressure pinched injection for parallel electrophoresis on array microfluidic chip.

    Science.gov (United States)

    Li, Bowei; Jiang, Lei; Xie, Hua; Gao, Yan; Qin, Jianhua; Lin, Bingcheng

    2009-09-01

    A micropump-actuated negative pressure pinched injection method is developed for parallel electrophoresis on a multi-channel LIF detection system. The system has a home-made device that could individually control 16-port solenoid valves and a high-voltage power supply. The laser beam is excitated and distributes to the array separation channels for detection. The hybrid Glass-PDMS microfluidic chip comprises two common reservoirs, four separation channels coupled to their respective pneumatic micropumps and two reference channels. Due to use of pressure as a driving force, the proposed method has no sample bias effect for separation. There is only one high-voltage supply needed for separation without relying on the number of channels, which is significant for high-throughput analysis, and the time for sample loading is shortened to 1 s. In addition, the integrated micropumps can provide the versatile interface for coupling with other function units to satisfy the complicated demands. The performance is verified by separation of DNA marker and Hepatitis B virus DNA samples. And this method is also expected to show the potential throughput for the DNA analysis in the field of disease diagnosis.

  16. Cardiovascular responses of men and women to lower body negative pressure

    Science.gov (United States)

    Montgomery, L. D.; Kirk, P. J.; Payne, P. A.; Gerber, R. L.; Newton, S. D.; Williams, B. A.

    1977-01-01

    Changes in blood flow and blood redistribution were measured by impedance plethysmography in the pelvic and leg regions of six male and four female subjects during three 5-min exposures to -20, -40, and -60 mm Hg lower body negative pressure (LBNP). Female subjects demonstrated significantly higher mean heart rate and lower leg blood flow indices than the male subjects during the recumbent control periods. Men had slightly higher mean resting systolic and diastolic blood pressures and higher mean control pelvic blood indices. Women demonstrated significantly less blood pooling in the legs and slightly less in the pelvic region than the men. All of the 18 tests with male subjects at -60 mm Hg were completed without initial signs of syncope, while only two of the tests with women were completed successfully without the subject exhibiting presyncopal conditions. Results indicate that impedance plethysmography can be used to measure segmental cardiovascular responses during LBNP and that females may be less tolerant to -60 mm Hg LBNP than males.

  17. Cardiovascular regulation in humans in response to oscillatory lower body negative pressure

    Science.gov (United States)

    Levenhagen, D. K.; Evans, J. M.; Wang, M.; Knapp, C. F.

    1994-01-01

    The frequency response characteristics of human cardiovascular regulation during hypotensive stress have not been determined. We therefore exposed 10 male volunteers to seven frequencies (0.004-0.1 Hz) of oscillatory lower body negative pressure (OLBNP; 0-50 mmHg). Fourier spectra of arterial pressure (AP), central venous pressure (CVP), stroke volume (SV), cardiac output (CO), heart rate (HR), and total peripheral resistance (TPR) were determined and first harmonic mean, amplitude, and phase angles with respect to OLBNP are presented. AP was relatively well regulated as demonstrated by small oscillations in half amplitude (3.5 mmHg) that were independent of OLBNP frequency and similar to unstressed control spectra. Due to the biomechanics of the system, the magnitudes of oscillations in calf circumference (CC) and CVP decreased with increasing frequency; therefore, we normalized responses by these indexes of the fluid volume shifted. The ratios of oscillations in AP to oscillations in CC increased by an order of magnitude, whereas oscillations in CVP to oscillations in CC and oscillations in AP to oscillations in CVP both tripled between 0.004 and 0.1 Hz. Therefore, even though the amount of fluid shifted by OLBNP decreased with increasing frequency, the magnitude of both CVP and AP oscillations per volume of fluid shifted increased (peaking at 0.08 Hz). The phase relationships between variables, particularly the increasing lags in SV and TPR, but not CVP, indicated that efferent responses with lags of 5-6 s could account for the observed responses. We conclude that, at frequencies below 0.02 Hz, the neural system of humans functioned optimally in regulating AP; OLBNP-induced decreases in SV (by as much as 50%) were counteracted by appropriate oscillations in HR and TPR responses. As OLBNP frequency increased, SV, TPR, and HR oscillations increasingly lagged the input and became less optimally timed for AP regulation.

  18. Therapy of acute and delayed spinal infections after spinal surgery treated with negative pressure wound therapy in adult patients

    Directory of Open Access Journals (Sweden)

    Pawel Zwolak

    2013-11-01

    Full Text Available We present the results of the treatment of infected primary or delayed spine wounds after spinal surgery using negative pressure wound therapy. In our institution (University Hospital Zurich, Switzerland nine patients (three women and six men; mean age 68.6, range 43- 87 years were treated in the period between January to December 2011 for non-healing spinal wounds. The treatment consisted of repeated debridements, irrigation and temporary closure with negative pressure wound therapy system. Three patients were admitted with a spinal epidural abscess; two with osteoporotic lumbar fracture; two with pathologic vertebra fracture and spinal cord compression, and two with vertebra fracture after trauma. All nine patients have been treated with antibiotic therapy. In one case the hardware has been removed, in three patients laminectomy was performed without instrumentation, in five patients there was no need to remove the hardware. The average hospital stay was 16.6 days (range 11-30. The average follow-up was 3.8, range 0.5-14 months. The average number of negative pressure wound therapy procedures was three, with the range 1-11. Our retrospective study focuses on the clinical problems faced by the spinal surgeon, clinical outcomes after spinal surgery followed by wound infection, and negative pressure wound therapy. Moreover, we would like to emphasize the importance for the patients and their relatives to be fully informed about the increased complications of surgery and about the limitations of treatment of these wounds with negative pressure wound therapy.

  19. Comparison of compensatory reserve during lower-body negative pressure and hemorrhage in nonhuman primates

    Science.gov (United States)

    Howard, Jeffrey T.; Mulligan, Jane; Grudic, Greg Z.; Convertino, Victor A.

    2016-01-01

    Compensatory reserve was measured in baboons (n = 13) during hemorrhage (Hem) and lower-body negative pressure (LBNP) using a machine-learning algorithm developed to estimate compensatory reserve by detecting reductions in central blood volume during LBNP. The algorithm calculates compensatory reserve index (CRI) from normovolemia (CRI = 1) to cardiovascular decompensation (CRI = 0). The hypothesis was that Hem and LBNP will elicit similar CRI values and that CRI would have higher specificity than stroke volume (SV) in predicting decompensation. Blood was removed in four steps: 6.25%, 12.5%, 18.75%, and 25% of total blood volume. Four weeks after Hem, the same animals were subjected to four levels of LBNP that was matched on the basis of their central venous pressure. Data (mean ± 95% confidence interval) indicate that CRI decreased (P < 0.001) from baseline during Hem (0.69 ± 0.10, 0.57 ± 0.09, 0.36 ± 0.10, 0.16 ± 0.08, and 0.08 ± 0.03) and LBNP (0.76 ± 0.05, 0.66 ± 0.08, 0.36 ± 0.13, 0.23 ± 0.11, and 0.14 ± 0.09). CRI was not different between Hem and LBNP (P = 0.20). Linear regression analysis between Hem CRI and LBNP CRI revealed a slope of 1.03 and a correlation coefficient of 0.96. CRI exhibited greater specificity than SV in both Hem (92.3 vs. 82.1) and LBNP (94.8 vs. 83.1) and greater ROC AUC in Hem (0.94 vs. 0.84) and LBNP (0.94 vs. 0.92). These data support the hypothesis that Hem and LBNP elicited the same CRI response, suggesting that measurement of compensatory reserve is superior to SV as a predictor of cardiovascular decompensation PMID:27030667

  20. Coagulation changes during lower body negative pressure and blood loss in humans.

    Science.gov (United States)

    van Helmond, Noud; Johnson, Blair D; Curry, Timothy B; Cap, Andrew P; Convertino, Victor A; Joyner, Michael J

    2015-11-01

    We tested the hypothesis that markers of coagulation activation are greater during lower body negative pressure (LBNP) than those obtained during blood loss (BL). We assessed coagulation using both standard clinical tests and thrombelastography (TEG) in 12 men who performed a LBNP and BL protocol in a randomized order. LBNP consisted of 5-min stages at 0, -15, -30, and -45 mmHg of suction. BL included 5 min at baseline and following three stages of 333 ml of blood removal (up to 1,000 ml total). Arterial blood draws were performed at baseline and after the last stage of each protocol. We found that LBNP to -45 mmHg is a greater central hypovolemic stimulus versus BL; therefore, the coagulation markers were plotted against central venous pressure (CVP) to obtain stimulus-response relationships using the linear regression line slopes for both protocols. Paired t-tests were used to determine whether the slopes of these regression lines fell on similar trajectories for each protocol. Mean regression line slopes for coagulation markers versus CVP fell on similar trajectories during both protocols, except for TEG α° angle (-0.42 ± 0.96 during LBNP vs. -2.41 ± 1.13°/mmHg during BL; P coagulation was accelerated as evidenced by shortened R-times (LBNP, 9.9 ± 2.4 to 6.2 ± 1.1; BL, 8.7 ± 1.3 to 6.4 ± 0.4 min; both P coagulation markers observed during BL. Copyright © 2015 the American Physiological Society.

  1. Does negative-pressure wound therapy influence subjacent bacterial growth? A systematic review.

    Science.gov (United States)

    Glass, Graeme E; Murphy, George R F; Nanchahal, Jagdeep

    2017-08-01

    Negative-pressure wound therapy is a ubiquitous wound management resource. The influence of NPWT on the bacterial bioburden of the subjacent wound remains unclear. We sought to examine the evidence. MEDLINE, Embase, PubMed, the Cochrane Database of Systematic Reviews and the Cochrane Controlled Trials Register were searched for articles quantitatively evaluating bacterial load under NPWT. Twenty-four studies met the inclusion criteria including 4 randomised controlled trials, 8 clinical series and 12 experimental studies. Twenty studies evaluated conventional NPWT, while 4 evaluated infiltration-based NPWT. While 8 studies using conventional NPWT failed to demonstrate an observable effect on bacterial load, 7 studies reported that NPWT was inherently bacteriostatic and 5 others reported species selectivity with suppression of non-fermentative gram-negative bacilli (NFGNB), including Pseudomonas spp. Simultaneously, there was some evidence of enhanced proliferation of gram-positive cocci where the niche was cleared of NFGNB. Two of the 4 studies using infiltration-based NPWT also reported selectively impaired proliferation of Pseudomonas spp. The assumption that NPWT suppresses bacterial proliferation is oversimplified. There is evidence that NPWT exhibits species selectivity, suppressing the proliferation of NFGNB. However, this may depopulate the niche for exploitation by gram-positive cocci. This, in turn, has implications for the use of NPWT where highly virulent strains of gram-positive cocci have been isolated and the duration of NPWT therapy and frequency of dressing changes. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  2. Initial treatment of respiratory distress syndrome with nasal intermittent mandatory ventilation versus nasal continuous positive airway pressure: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Amir-Mohammad Armanian

    2014-01-01

    Full Text Available Background: Neonatal respiratory distress syndrome (RDS in premature infants who survived and its complications are a common problem. Due to high morbidity and mechanical ventilation (MV nowadays researchers in interested minimizing MV. To determine, in very low birth weight (BW preterm neonates with RDS, if initial treatment with nasal intermittent mandatory ventilation (early NIMV compared with early nasal continuous positive airway pressure (early NCPAP obtains more favorable outcomes in terms of the duration of treatment, and the need for endotracheal tube ventilation. Methods: In this single-center randomized control trial study, infants (BW ≤ 1500 g and/or gestational age ≤ 34 weeks with respiratory distress were considered eligible. Forty-four infants were randomly assigned to receive early-NIMV and 54 comparable infants to early-NCPAP. Surfactants were given, when FIO 2 requirement was of >30%. Primary outcomes were failure of noninvasive respiratory support, that is, the need for MV in the first 48 h of life and for the duration of noninvasive respiratory support in each group. Results: 98 infants were enrolled (44 in the NIMV and 54 in the NCPAP group. The Preventive power of MV of NIMV usage (95.5% was not lower than the NCPAP (98.1% strength (hazard ratio: 0.21 (95% confidence interval: 0.02-2.66; P: 0.23. The duration of noninvasive respiratory support in the NIMV group was significantly shorter than NCPAP (the median (range was 24 (18.00-48.00 h versus 48.00 (22.00-120.00 h in NIMV versus NCPAP groups; P < 0.001. Similarly, the duration of dependency on oxygen was less, for NIMV (the median (range was 96.00 (41.00-504.00 h versus144.00 (70.00-1130.00 h in NIMV versus NCPAP groups; P: 0.009. Interestingly, time to full enteral feeds and length of hospital stay were more favorable in the NIMV versus the NCPAP group. Conclusions: Initial treatment of RDS with NIMV was safe, and well tolerated. Furthermore, NIMV had excellent

  3. Takotsubo cardiomyopathy precipitated by negative pressure pulmonary oedema following total thyroidectomy

    Directory of Open Access Journals (Sweden)

    K S Bharathi

    2016-01-01

    Full Text Available 'Takotsubo cardiomyopathy (TCM' or 'stress cardiomyopathy' is a reversible cardiomyopathy that is precipitated by intense emotional or physical stress. This syndrome is characterised by symptoms mimicking acute coronary syndrome with transient systolic dysfunction associated with regional wall motion abnormalities, which extend beyond a single coronary vascular bed in the absence of obstructive coronary vascular disease. The presentation of TCM and myocardial infarction is similar with sudden onset of chest pain, breathlessness as well as abnormalities in both the electrocardiogram and cardiac enzymes. It is difficult to differentiate between the two until cardiac catheterisation establishes the diagnosis. We report a case of TCM in a post-menopausal female, precipitated by negative pressure pulmonary oedema following total thyroidectomy in whom timely cardiac catheterisation established the diagnosis and influenced the management. Heightened awareness of this unique cardiomyopathy is essential to have a high index of suspicion in at-risk population for the prompt diagnosis of stress-related cardiomyopathy syndromes occurring in the perioperative period.

  4. Use of a risk assessment method to improve the safety of negative pressure wound therapy.

    Science.gov (United States)

    Lelong, Anne-Sophie; Martelli, Nicolas; Bonan, Brigitte; Prognon, Patrice; Pineau, Judith

    2014-06-01

    To conduct a risk analysis of the negative pressure wound therapy (NPWT) care process and to improve the safety of NPWT, a working group of nurses, hospital pharmacists, physicians and hospital managers performed a risk analysis for the process of NPWT care. The failure modes, effects and criticality analysis (FMECA) method was used for this analysis. Failure modes and their consequences were defined and classified as a function of their criticality to identify priority actions for improvement. By contrast to classical FMECA, the criticality index (CI) of each consequence was calculated by multiplying occurrence, severity and detection scores. We identified 13 failure modes, leading to 20 different consequences. The CI of consequences was initially 712, falling to 357 after corrective measures were implemented. The major improvements proposed included the establishment of 6-monthly training cycles for nurses, physicians and surgeons and the introduction of computerised prescription for NPWT. The FMECA method also made it possible to prioritise actions as a function of the criticality ranking of consequences and was easily understood and used by the working group. This study is, to our knowledge, the first to use the FMECA method to improve the safety of NPWT. © 2012 The Authors. International Wound Journal © 2012 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  5. Impact of negative affectivity and trait forgiveness on aortic blood pressure and coronary circulation.

    Science.gov (United States)

    Sanchez-Gonzalez, Marcos A; May, Ross W; Koutnik, Andrew P; Fincham, Frank D

    2015-02-01

    Prior research suggests that negative affectivity (NA) may have a direct adverse effect on coronary circulation, whereas forgiveness may provide cardioprotection. This study examined whether NA and forgiveness were independently related to aortic hemodynamics and the subendocardial viability index (SVI), a marker of coronary perfusion. A sample of 131 adults (M = 21.11 years, SD = 2.52) were evaluated for NA (depression, anxiety, and anger symptoms) and forgiveness (Tendency to Forgive Scale; TTF). Aortic hemodynamic parameters via applanation tonometry were assessed at rest and during sympathostimulation (cold pressor test; CPT). Hierarchical multiple regression analyses of resting values showed that NA was related to higher aortic blood pressure (ABP) and lower SVI. After controlling for demographics and for NA, TTF scores were significantly associated with decreased ABP, but increased SVI. CPT changes from baseline indicated that, after controlling for demographics and NA, TTF scores were significantly associated with SVI. Results indicate that NA significantly predicts ABP and decreased SVI. Conversely, forgiveness seems to provide cardioprotection by evoking decreased ABP while improving SVI. © 2014 Society for Psychophysiological Research.

  6. Bronchial fistula closure with negative pressure wound therapy: a feasible and cost-effective treatment.

    Science.gov (United States)

    Nunes, Rodrigo Barboza; Müller, Bruno Francisco; Cipriano, Federico Enrique Garcia; Coltro, Pedro Soler; Farina, Jayme Adriano

    2016-01-01

    Treatment of bronchial fistula (BF) after pulmonary lobectomy is a challenge. Often, patients require long hospital stay, have recurrent empyema and pneumonia, are susceptible to sepsis, often need broad-spectrum antibiotics, as well as various surgical approaches. With the advent and growing evidence of the benefits of negative pressure therapy (NPT), its use in some patients with BF has been reported with encouraging results concerning its feasibility and cost-effectiveness. The aim of this study was to demonstrate the application of NPT as a resource for BF treatment and comparatively analyze the overall cost of treatment. RESUMO O tratamento de fístula brônquica (FB) após lobectomia pulmonar é um desafio. Muitas vezes, o paciente demanda longo tempo de internação, apresenta recidivas de empiema e pneumonia, pode evoluir para sepse, frequentemente necessita de antibioticoterapia de amplo espectro, bem como de várias abordagens cirúrgicas. Com o advento e acúmulo de evidências dos benefícios da terapia por pressão negativa (TPN), seu uso em alguns pacientes com FB tem sido relatado com resultados animadores relativos à sua viabilidade e ao seu custo-efetividade. O objetivo deste estudo foi demonstrar a aplicação de TPN como recurso para tratamento da FB e analisar comparativamente o custo global do seu tratamento.

  7. The use of negative pressure wound therapy in the treatment of infected wounds. Case studies.

    Science.gov (United States)

    Jones, Daniel de Alcântara; Neves Filho, Wilson Vasconcelos; Guimarães, Janice de Souza; Castro, Daniel de Araújo; Ferracini, Antonio Marcos

    2016-01-01

    To evaluate the results and benefits obtained from the topical use of negative pressure wound therapy (NPWT) in patients with infected wounds. This was a retrospective study of 20 patients (17 males and three females, mean age 42 years) with infected wounds treated using NPWT. The infected wounds were caused by trauma. The treatment system used was VAC. ® (Vacuum Assisted Closure, KCI, San Antonio, United States) applied to the wound in continuous mode from 100 to 125 mmHg. The parameters related to the wounds (location, number of VAC changes, the size of the defects in the soft parts, and the evolution of the state of the wound), length of hospital stay, length of intravenous antibiotic therapy, and complications related to the use of this therapy were evaluated. The mean length of the hospital stay, use of NPWT, and antibacterial therapy were 41 days, 22.5 days, and 20 days respectively. The use of the VAC led to a mean reduction of 29% in the wound area (95.65-68.1 cm 2 ; p  wound with complete eradication of the infection. No complication directly caused by NPWT was observed. NPWT stimulates infection-free scar tissue formation in a short time, and is a quick and comfortable alternative to conventional infected wounds treatment methods.

  8. Negative-Pressure Wound Therapy for Ludwig’s Angina: A Case Series

    Directory of Open Access Journals (Sweden)

    Nainika Nanda, BA

    2017-11-01

    Full Text Available Summary:. Negative-pressure wound therapy (NPWT is a well-established therapeutic approach for various complex wound classes. There is currently limited information on the use of NPWT for the scope of head and neck wounds. However, NPWT has been used successfully in some cases, including malignancy, infection, and trauma. In West Virginia, the incidence of dental-related infections leading to Ludwig’s Angina is high due to lack of access to dental care. Our case series describes the application of vacuum-based therapy in conjunction with antibiotic therapy for quick, effective closure of deep tissue infections before definitive complex wound repair via graft and flap reconstructions. Over a period of 3 months, 2 patients with submental infections extending to the lateral neck demonstrated clean, efficient wound closure with NPWT for less than 14 days while hospitalized at West Virginia University Medicine. Outpatient follow-up with these patients demonstrated excellent cosmetic outcomes with minimal contracture or hypertrophy of healing tissue. NPWT promotes wound healing through decreased edema, improved perfusion, and increased granulation of tissue based on our findings. Our series encourages the use of NPWT for initial closure of complex wounds secondary to deep neck infections.

  9. Negative expiratory pressure (NEP) parameters can predict obstructive sleep apnea syndrome in snoring patients.

    Science.gov (United States)

    Rouatbi, Sonia; Tabka, Zouhair; Dogui, Mohamed; Abdelghani, Ahmed; Guénard, Hervé

    2009-01-01

    The objective of this study was to assess whether parameters of the negative expiratory pressure (NEP) technique are able to detect obstructive sleep apnea syndrome (OSAS) in snoring patients. A cross-sectional study included 42 OSAS patients diagnosed by polysomnography (PSG), 34 simple snorers, and 32 healthy subjects. Lung function was measured by using a plethysmograph and the NEP technique was performed with the patient in the seated and supine positions in a random order. The depression was fixed to 5 cmH(2)O. All patients had normal forced expiratory flow/volume loops. Apneic patients had lower Dflow in both positions with a number of oscillations on the expiratory curve obtained with NEP and an expiratory flow limitation (EFL) in the supine position higher than that of other groups (p < 0.05). Changing from the sitting to the supine position raised the EFL of the three groups, with a significant decrease in Dflow and an increase in the number of oscillations in snoring and OSAS patients (p < 0.05). The analysis of variance showed that only the number of oscillations was significantly different between apneic and snoring patients. NEP constitutes a simple and useful tool for the screening OSAS by EFL, especially the number of oscillations obtained with NEP.

  10. The use of negative pressure wound therapy in the treatment of infected wounds. Case studies

    Directory of Open Access Journals (Sweden)

    Daniel de Alcântara Jones

    Full Text Available ABSTRACT OBJECTIVE: To evaluate the results and benefits obtained from the topical use of negative pressure wound therapy (NPWT in patients with infected wounds. METHODS: This was a retrospective study of 20 patients (17 males and three females, mean age 42 years with infected wounds treated using NPWT. The infected wounds were caused by trauma. The treatment system used was VAC.(r (Vacuum Assisted Closure, KCI, San Antonio, United States applied to the wound in continuous mode from 100 to 125 mmHg. The parameters related to the wounds (location, number of VAC changes, the size of the defects in the soft parts, and the evolution of the state of the wound, length of hospital stay, length of intravenous antibiotic therapy, and complications related to the use of this therapy were evaluated. RESULTS: The mean length of the hospital stay, use of NPWT, and antibacterial therapy were 41 days, 22.5 days, and 20 days respectively. The use of the VAC led to a mean reduction of 29% in the wound area (95.65-68.1 cm2; p < 0.05. Only one patient did not show any improvement in the final appearance of the wound with complete eradication of the infection. No complication directly caused by NPWT was observed. CONCLUSION: NPWT stimulates infection-free scar tissue formation in a short time, and is a quick and comfortable alternative to conventional infected wounds treatment methods.

  11. Randomized clinical trial to compare negative-pressure wound therapy approaches with low and high pressure, silicone-coated dressing, and polyurethane foam dressing.

    Science.gov (United States)

    Lavery, Lawrence A; La Fontaine, Javier; Thakral, Gaurav; Kim, Paul J; Bhavan, Kavita; Davis, Kathryn E

    2014-03-01

    This study was designed to compare two approaches to negative-pressure wound therapy: 125-mmHg pressure with a polyurethane foam dressing and 75-mmHg pressure with a silicone-coated dressing. Forty patients with diabetic foot wounds, after incision and drainage or amputation for infection, were assigned randomly to negative-pressure wound therapy with 75-mmHg continuous pressure with a silicone-covered dressing (75-mmHg group) or 125-mmHg with a polyurethane foam dressing (125-mmHg group) for up to 4 weeks or until surgical closure. There was no difference in the proportion of wounds that were closed surgically (75-mmHg group, 50 percent; 125-mmHg group, 60 percent), wounds that demonstrated 50 percent wound area reduction (75-mmHg group, 65 percent; 125-mmHg group, 80 percent), or wounds that demonstrated 50 percent wound volume reduction after 4 weeks of therapy (75-mmHg group, 95 percent; 125-mmHg group, 90 percent). The authors' results suggest that there was no difference in outcomes in wounds treated with low pressure (75 mmHg) with a silicone-coated interface and high pressure (125 mmHg) with a polyurethane foam interface. Therapeutic, II.

  12. Patients experiences of negative pressure wound therapy at home for the treatment of deep perivascular groin infection after vascular surgery.

    Science.gov (United States)

    Monsen, Christina; Acosta, Stefan; Kumlien, Christine

    2017-05-01

    To explore experiences of negative pressure wound therapy at home, in patients with deep perivascular groin infection after vascular surgery and management in daily life. Deep surgical site infection after vascular surgery with exposed vessels often requires long-term treatment with negative pressure wound therapy, and continued therapy at home has become routine. An explorative qualitative study. Nine men and six women with a deep surgical site infection in the groin after vascular surgery, treated in their home with negative pressure wound therapy, were interviewed. The interviews were analysed using manifest and latent content analysis. Undergoing negative pressure wound therapy at home meant a transition from being a dependent patient to a person who must have self-care competence and be involved in their own care. A need to feel prepared for this before discharge from hospital was expressed. Lack of information and feelings of uncertainty prolonged the time before feeling confident in managing the treatment. The informants gradually accepted the need to be tied up to a machine, became competent in its management and found solutions to perform everyday tasks. Overall, it was a relief to be treated at home. Several benefits of negative pressure wound therapy at home were expressed. However, unnecessary stress and anxiety were experienced due to a lack of information on the treatment and instruction concerning the equipment. Adequate information and education must therefore be provided to facilitate the transition from a patient to a person with self-care competence and ability to manage this treatment at home. The findings revealed a need for more support and knowledge in their transition from hospital care to home care with negative pressure wound therapy. Routines must be established that ensure patient safety and security in treatment at home. © 2016 John Wiley & Sons Ltd.

  13. Relaxation effects in ionic mobility and cluster formation: negative ions in SF{sub 6} at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Juarez, A M; De Urquijo, J; Hinojosa, G [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, PO Box 48-3, 62251, Cuernavaca, Mor. (Mexico); Hernandez-Avila, J L [Departamento de Energia, Universidad Autonoma Metropolitana, Av. San Pablo 180, 02200 Mexico, D.F. (Mexico); Basurto, E, E-mail: juarez@fis.unam.m [Departamento de Ciencias Basicas, Universidad Autonoma Metropolitana, Av. San Pablo 180, 02200 Mexico, D.F. (Mexico)

    2010-06-15

    The relaxation effects of the ionic mobility and the formation of negative-ion clusters in SF{sub 6} are studied in this work. For this purpose, we have measured the mobility of negative ions in SF{sub 6} over the pressure range 100-800 Torr at a fixed value of density-normalized electric field, E/N, of 20 Td (1 Townsend = 10{sup -17} V cm{sup 2}). The data obtained show a clear dependence of the negative-ion drift velocity on drift distance. It is observed that the drift velocity (mobility) reaches a steady-state value only for drift distances above 2 cm, over the studied pressure range. In addition to this, we have observed that the ionic mobility depends strongly on the gas pressure. An explanation of this dependence of the ionic mobility on gas pressure is given in terms of a negative-ion clustering formation process. It was found that the assumption of a linear dependence of the cluster ion mass on pressure provides a satisfactory explanation for the observed mobilities.

  14. Frequency pressure transducer with a sensitivity of mem capacitor on the basis of transistor structure with negative resistance

    Science.gov (United States)

    Osadchuk, Oleksandr V.; Osadchuk, Iaroslav O.; Suleimenov, Batyrbek; Zyska, Tomasz; Arman, Abenov; Tleshova, Akmaral; GrÄ dz, Å.»aklin

    2017-08-01

    In the article the pressure transducer with frequency output based on the structure of the bipolar-field transistors with negative resistance and tenso sensitive MEMS capacitor has been considered. A mathematical model of the frequency pressure transducer in dynamic regime has been developed that allowed to determine the voltage or current in the circuit at any given moment in time when acting this pressure. Analytical expressions of the conversion function and sensitivity equation has been received. The sensitivity of the developed device is between 0,95kHz/kPa to 1,65kHz/kPa.

  15. Cost-utility analysis of negative pressure wound therapy in high-risk cesarean section wounds.

    Science.gov (United States)

    Tuffaha, Haitham W; Gillespie, Brigid M; Chaboyer, Wendy; Gordon, Louisa G; Scuffham, Paul A

    2015-05-15

    Obese women undergoing cesarean section are at increased risk of postoperative infection. There is growing interest in negative pressure wound therapy (NPWT) to prevent closed surgical incision complications including surgical site infection; however, the evidence on the effectiveness and cost-effectiveness of this technology is limited. The objective of this study was to evaluate the cost-effectiveness of NPWT compared with that of standard dressing in preventing surgical site infection in obese women undergoing elective cesarean section based on current evidence and to estimate the value and optimal design of additional research to study this technology. The analysis was from the perspective of Queensland Health, Australia, using a decision model. Parameters were obtained from the published literature, a pilot clinical trial, and expert opinion. Monte Carlo simulation was performed to calculate the net monetary benefit, characterize decision uncertainty, and estimate the value of additional research. Comparing the expected monetary benefits and costs of alternative trial sample sizes informed the optimal future study design. The incremental net monetary benefit of NPWT was Australian dollars 70, indicating that NPWT is cost-effective compared with that of standard dressing. The probability of NPWT being cost-effective was 65%. The estimated value of additional research to resolve decision uncertainty would be Australian dollars 2.7 million. The optimal sample size of a future trial investigating the relative effectiveness of NPWT would be 200 patients per arm. Based on the current evidence, NPWT is cost-effective; however, there is high uncertainty surrounding the decision to adopt this technology. Additional research is worthwhile before implementation. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Clinical Features of Patients with Diffuse Alveolar Hemorrhage due to Negative-Pressure Pulmonary Edema.

    Science.gov (United States)

    Contou, Damien; Voiriot, Guillaume; Djibré, Michel; Labbé, Vincent; Fartoukh, Muriel; Parrot, Antoine

    2017-08-01

    Diffuse alveolar hemorrhage (DAH) with negative-pressure pulmonary edema (NPPE) is an uncommon yet life-threatening condition. We aimed at describing the circumstances, clinical, radiological, and bronchoscopic features, as well as the outcome of patients with NPPE-related DAH. We performed a retrospective, observational cohort study, using data prospectively collected over 35 years in an intensive care unit (ICU). Of the 149 patients admitted for DAH, we identified 18 NPPE episodes in 15 patients, one admitted four times for recurrent NPPE-related DAH. The patients were primarily young, male, and athletic. The NPPE setting was postoperative (n = 12/18, 67%) or following generalized tonic-clonic seizures (n = 6/18, 33%). Hemoptysis was almost constant (n = 17/18, 94%), yet rarely massive (>200 cc, n = 1/18, 6%), with anemia observed in 10 (56%) episodes. The DAH triad (hemoptysis, anemia, and pulmonary infiltrates) was observed in 50% of episodes (n = 9/18), and acute respiratory failure in 94% (n = 17/18). Chest computed tomography revealed diffuse bilateral ground glass opacities (n = 10/10, 100%), while bronchoscopy detected bilateral hemorrhage (n = 12/12, 100%) and macroscopically bloody bronchoalveolar lavage, with siderophage absence in most (n = 7/8, 88%), indicating acute DAH. While one episode proved fatal, the other 17 recovered rapidly, with a mean ICU stay lasting 4.6 (2-15) days. Typically, the evolution was rapidly favorable under supportive care. NPPE-related DAH is a rare life-threatening condition occurring primarily after tonic-clonic generalized seizure or generalized anesthesia. Clinical circumstances are a key to its diagnosis. Early diagnosis and recognition likely allow for successful management of this potentially serious complication, whereas ictal-DAH appears ominous in epileptic patients.

  17. Negative pressure wound therapy after partial diabetic foot amputation: a multicentre, randomised controlled trial.

    Science.gov (United States)

    Armstrong, David G; Lavery, Lawrence A

    2005-11-12

    Diabetic foot wounds, particularly those secondary to amputation, are very complex and difficult to treat. We investigated whether negative pressure wound therapy (NPWT) improves the proportion and rate of wound healing after partial foot amputation in patients with diabetes. We enrolled 162 patients into a 16-week, 18-centre, randomised clinical trial in the USA. Inclusion criteria consisted of partial foot amputation wounds up to the transmetatarsal level and evidence of adequate perfusion. Patients who were randomly assigned to NPWT (n=77) received treatment with dressing changes every 48 h. Control patients (n=85) received standard moist wound care according to consensus guidelines. NPWT was delivered through the Vacuum Assisted Closure (VAC) Therapy System. Wounds were treated until healing or completion of the 112-day period of active treatment. Analysis was by intention to treat. This study has been registered with , number NCT00224796. More patients healed in the NPWT group than in the control group (43 [56%] vs 33 [39%], p=0.040). The rate of wound healing, based on the time to complete closure, was faster in the NPWT group than in controls (p=0.005). The rate of granulation tissue formation, based on the time to 76-100% formation in the wound bed, was faster in the NPWT group than in controls (p=0.002). The frequency and severity of adverse events (of which the most common was wound infection) were similar in both treatment groups. NPWT delivered by the VAC Therapy System seems to be a safe and effective treatment for complex diabetic foot wounds, and could lead to a higher proportion of healed wounds, faster healing rates, and potentially fewer re-amputations than standard care.

  18. A prospective randomized evaluation of negative-pressure wound dressings for diabetic foot wounds.

    Science.gov (United States)

    Eginton, Mark T; Brown, Kellie R; Seabrook, Gary R; Towne, Jonathan B; Cambria, Robert A

    2003-11-01

    Optimal treatment for large diabetic foot wounds is ill defined. The purpose of this study was to compare the rate of wound healing with the Vacuum Assisted Closure device trade mark (VAC) to conventional moist dressings in the treatment of large diabetic foot wounds. Diabetics with significant soft tissue defects of the foot were considered for enrollment. Patients were randomized to receive either moist gauze dressings or VAC treatments for 2 weeks, after which they were treated with the alternative dressing for an additional 2 weeks. Wounds were photographed weekly and wound dimensions calculated in a blinded fashion with spatial analysis software. Percent change in wound dimensions were calculated and compared for each weekly assessment and over 2 weeks of therapy with each dressing type. Ten patients were enrolled in the trial, but two were lost to follow-up and two were withdrawn. Complete data were available for analysis on seven wounds in six patients. Average length, width, and depth of the wounds at initiation of the trial was 7.7, 3.5, and 3.1 cm, respectively. Only the wound depth was significantly decreased over the weeks of the trial to 1.2 cm ( p VAC dressings decreased the wound volume and depth significantly more than moist gauze dressings (59% vs. 0% and 49% vs. 8%, respectively). VAC dressings were associated with a decrease in all wound dimensions while wound length and width increased with moist dressings. In summary, over the first several weeks of therapy, VAC dressings decreased wound depth and volume more effectively than moist gauze dressings. Negative-pressure wound treatment may accelerate closure of large foot wounds in the diabetic patient.

  19. Loss of protein, immunoglobulins, and electrolytes in exudates from negative pressure wound therapy.

    Science.gov (United States)

    Hourigan, Leslie A; Hourigan, Leslie; Linfoot, John A; Linfoot, John; Chung, Kevin K; Chung, Kevin; Dubick, Michael A; Dubick, Michael; Rivera, Rachael L; Rivera, Racheal; Jones, John A; Salinas, Reuben D; Salinas, Reuben; Mann, Elizabeth A; Wade, Charles E; Wade, Charles; Wolf, Steven E; Baskin, Toney W; Baskin, Toney

    2010-10-01

    A relatively new technology in wound care, negative pressure wound therapy (NPWT), has become widely used for the management of open abdomens and soft tissue wounds and provides a means to collect wound exudate to quantify protein loss. A prospective observational study was conducted in surgical, trauma, or burn patients (8 patients with open abdomens and 9 patients with acute soft tissue wounds on NPWT). NPWT exudate was collected and assayed to characterize loss of protein, electrolyte, and immunoglobulins over multiple days of NPWT. Total protein was present in open abdomen NPWT exudate, 2.9 ± 0.9 g/dL. In the soft tissue wound exudate, a similar mean concentration was found, 2.59 ± 0.6 g/dL (P = .34). Exudate concentrations of albumin, urea nitrogen, immunoglobulins, and electrolytes between wound types were also not significantly different. There were significant (P = .03) differences in the median volume of exudate, 1031 mL/d for open abdomens in contrast to 245 mL/d soft tissue wounds. Therefore, 24-hour losses of proteins and electrolytes were greater in patients with open abdomens than soft tissue wounds. Mean total protein loss was 25 ± 17 g/d for open abdomens and 8 ± 5 g/d for soft tissue wounds. There are significant losses of proteins in wound exudate. As there is no significant difference in the concentration of total protein between wound type, the rate of loss may be calculated as 2.9 g/dL times the volume of wound exudate. The rate of protein loss from wounds is similar to the presently assumed insensible loss rate of 12-25 g/d.

  20. Suture Technique to Prevent Air Leakage during Negative-Pressure Wound Therapy in Fournier Gangrene.

    Science.gov (United States)

    Chang, Feng-Shu; Chou, Chieh; Hu, Chuan-Yu; Huang, Shu-Hung

    2018-01-01

    The use of negative-pressure wound therapy (NPWT) for Fournier gangrene management is well documented; however, it is difficult to fixate GranuFoam dressings and maintain an airtight seal over the perineum area. We developed a simple method to facilitate GranuFoam fixation and improve airtight sealing. The Fournier's gangrene severity index (FGSI) score less than 9 was collected in from January 2015 to October 2016. All 13 patients underwent fasciotomy, and NPWT was applied directly on fasciotomy wounds after the debridement of infected tissue. Partial wound closure was performed, and a portion of GranuFoam was inserted to facilitate fixation. The seal check was converted to a 0-10 scale score that was recorded every 4 hours during NPWT. Patient profiles including medical history, FGSI, method of wound closure, and length of stay were collected in this study. The median age of the patients was 62 (38-76) years. The mean FGSI score was 4.3 ± 3.1. The average duration of NPWT was 17.5 ± 11.5 days, and the average seal check score was 0.8 ± 0.5. No seal check alarms were noted during the study. Successful wound closure was achieved in all patients without using additional reconstruction methods such as skin grafting or muscle flap coverage. The present results suggest that partial wound-edge closure and in situ GranuFoam fixation improve the NPWT leaks in Fournier gangrene wounds. Furthermore, this method is simple to learn and can be useful in applying NPWT to anatomically difficult areas.

  1. Evaluation of a Decision-Making Curriculum for Teaching Adolescents with Disabilities to Resist Negative Peer Pressure

    Science.gov (United States)

    Khemka, Ishita; Hickson, Linda; Mallory, Sarah B.

    2016-01-01

    This study was designed to assess the impact of a decision-making curriculum (PEER-DM) on the social peer relationship knowledge and self-protective decision-making skills of adolescents with disabilities in hypothetical situations involving negative peer pressure. A randomized design was used to assign students with disabilities from…

  2. Major bleeding during negative pressure wound/VAC (R) - therapy for postsurgical deep sternal wound infection - a critical appraisal

    NARCIS (Netherlands)

    van Wingerden, J.J.; Segers, P.; Jekel, L.

    2011-01-01

    Negative-pressure wound therapy, commercially known as vacuum-assisted closure (V.A.C.(R)) therapy, has become one of the most popular (and efficacious) interim (prior to flap reconstruction) or definite methods of managing deep sternal wound infection. Complications such as profuse bleeding, which

  3. Water quality effects of intermittent water supply in Arraiján, Panama.

    Science.gov (United States)

    Erickson, John J; Smith, Charlotte D; Goodridge, Amador; Nelson, Kara L

    2017-05-01

    Intermittent drinking water supply is common in low- and middle-income countries throughout the world and can cause water quality to degrade in the distribution system. In this study, we characterized water quality in one study zone with continuous supply and three zones with intermittent supply in the drinking water distribution network in Arraiján, Panama. Low or zero pressures occurred in all zones, and negative pressures occurred in the continuous zone and two of the intermittent zones. Despite hydraulic conditions that created risks for backflow and contaminant intrusion, only four of 423 (0.9%) grab samples collected at random times were positive for total coliform bacteria and only one was positive for E. coli. Only nine of 496 (1.8%) samples had turbidity >1.0 NTU and all samples had ≥0.2 mg/L free chlorine residual. In contrast, water quality was often degraded during the first-flush period (when supply first returned after an outage). Still, routine and first-flush water quality under intermittent supply was much better in Arraiján than that reported in a previous study conducted in India. Better water quality in Arraiján could be due to better water quality leaving the treatment plant, shorter supply outages, higher supply pressures, a more consistent and higher chlorine residual, and fewer contaminant sources near pipes. The results illustrate that intermittent supply and its effects on water quality can vary greatly between and within distribution networks. The study also demonstrated that monitoring techniques designed specifically for intermittent supply, such as continuous pressure monitoring and sampling the first flush, can detect water quality threats and degradation that would not likely be detected with conventional monitoring. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Incisional negative pressure therapy to prevent wound complications following cesarean section in morbidly obese women: a pilot study.

    Science.gov (United States)

    Mark, Katrina S; Alger, Lindsay; Terplan, Mishka

    2014-08-01

    We sought to evaluate the efficacy of incisional negative pressure therapy in decreasing postoperative wound complications when placed prophylactically over clean, closed incisions following cesarean section in obese patients. This was a retrospective cohort study comparing rates of wound complications following cesarean sections in morbidly obese women prior to and following the institution of standard use of prophylactic incisional negative pressure therapy. All women with a body mass index greater than 45 kg/m(2) undergoing cesarean section in a 2-year period in a single institution were included. The exposure was incisional negative pressure therapy, which began in September 2009, versus standard wound dressing used in the previous year. The main outcome was wound complication identified by ICD-9 codes. Demographic and wound outcomes were compared with χ(2) and t tests. Stata version 11.0 was used for all analysis. A total of 63 women met the inclusion criteria, 21 of whom received negative pressure wound therapy. The historical comparison and exposure groups were similar in all characteristics studied with the exceptions of length of surgery (64 vs 76 minutes, P = .03), length of labor (78 vs 261 minutes, P = .02), scheduled versus nonscheduled (77% vs 52%, P = .04), and mean age (29.5 vs 26.1 years, P = .04), respectively. There were 5 wound complications in the control group (10.4%) and none (0%) in the study group (P = .15). This pilot study suggests a decrease in wound complications in morbidly obese women receiving incisional negative pressure therapy following cesarean section. © The Author(s) 2013.

  5. The partitioning of nanoparticles to endothelium or interstitium during ultrasound-microbubble-targeted delivery depends on peak-negative pressure

    Energy Technology Data Exchange (ETDEWEB)

    Hsiang, Y.-H.; Song, J.; Price, R. J., E-mail: rprice@virginia.edu [University of Virginia, Department of Biomedical Engineering (United States)

    2015-08-15

    Patients diagnosed with advanced peripheral arterial disease often face poor prognoses and have limited treatment options. For some patient populations, the therapeutic growth of collateral arteries (i.e. arteriogenesis) that bypass regions affected by vascular disease may become a viable treatment option. Our group and others are developing therapeutic approaches centered on the ability of ultrasound-activated microbubbles to permeabilize skeletal muscle capillaries and facilitate the targeted delivery of pro-arteriogenic growth factor-bearing nanoparticles. The development of such approaches would benefit significantly from a better understanding of how nanoparticle diameter and ultrasound peak-negative pressure affect both total nanoparticle delivery and the partitioning of nanoparticles to endothelial or interstitial compartments. Toward this goal, using Balb/C mice that had undergone unilateral femoral artery ligation, we intra-arterially co-injected nanoparticles (50 and 100 nm) with microbubbles, applied 1 MHz ultrasound to the gracilis adductor muscle at peak-negative pressures of 0.7, 0.55, 0.4, and 0.2 MPa, and analyzed nanoparticle delivery and distribution. As expected, total nanoparticle (50 and 100 nm) delivery increased with increasing peak-negative pressure, with 50 nm nanoparticles exhibiting greater tissue coverage than 100 nm nanoparticles. Of particular interest, increasing peak-negative pressure resulted in increased delivery to the interstitium for both nanoparticle sizes, but had little influence on nanoparticle delivery to the endothelium. Thus, we conclude that alterations to peak-negative pressure may be used to adjust the fraction of nanoparticles delivered to the interstitial compartment. This information will be useful when designing ultrasound protocols for delivering pro-arteriogenic nanoparticles to skeletal muscle.

  6. The partitioning of nanoparticles to endothelium or interstitium during ultrasound-microbubble-targeted delivery depends on peak-negative pressure

    International Nuclear Information System (INIS)

    Hsiang, Y.-H.; Song, J.; Price, R. J.

    2015-01-01

    Patients diagnosed with advanced peripheral arterial disease often face poor prognoses and have limited treatment options. For some patient populations, the therapeutic growth of collateral arteries (i.e. arteriogenesis) that bypass regions affected by vascular disease may become a viable treatment option. Our group and others are developing therapeutic approaches centered on the ability of ultrasound-activated microbubbles to permeabilize skeletal muscle capillaries and facilitate the targeted delivery of pro-arteriogenic growth factor-bearing nanoparticles. The development of such approaches would benefit significantly from a better understanding of how nanoparticle diameter and ultrasound peak-negative pressure affect both total nanoparticle delivery and the partitioning of nanoparticles to endothelial or interstitial compartments. Toward this goal, using Balb/C mice that had undergone unilateral femoral artery ligation, we intra-arterially co-injected nanoparticles (50 and 100 nm) with microbubbles, applied 1 MHz ultrasound to the gracilis adductor muscle at peak-negative pressures of 0.7, 0.55, 0.4, and 0.2 MPa, and analyzed nanoparticle delivery and distribution. As expected, total nanoparticle (50 and 100 nm) delivery increased with increasing peak-negative pressure, with 50 nm nanoparticles exhibiting greater tissue coverage than 100 nm nanoparticles. Of particular interest, increasing peak-negative pressure resulted in increased delivery to the interstitium for both nanoparticle sizes, but had little influence on nanoparticle delivery to the endothelium. Thus, we conclude that alterations to peak-negative pressure may be used to adjust the fraction of nanoparticles delivered to the interstitial compartment. This information will be useful when designing ultrasound protocols for delivering pro-arteriogenic nanoparticles to skeletal muscle

  7. Pressure transduction and fluid evacuation during conventional negative pressure wound therapy of the open abdomen and NPWT using a protective disc over the intestines

    Directory of Open Access Journals (Sweden)

    Lindstedt Sandra

    2012-03-01

    Full Text Available Abstract Background Negative pressure wound therapy (NPWT has gained acceptance among surgeons, for the treatment of open abdomen, since very high closure rates have been reported with this method, compared to other kinds of wound management for the open abdomen. However, the method has occasionally been associated with increased development of fistulae. We have previously shown that NPWT induces ischemia in the underlying small intestines close to the vacuum source, and that a protective disc placed between the intestines and the vacuum source prevents the induction of ischemia. In this study we compare pressure transduction and fluid evacuation of the open abdomen with conventional NPWT and NPWT with a protective disc. Methods Six pigs underwent midline incision and the application of conventional NPWT and NPWT with a protective disc between the intestines and the vacuum source. The pressure transduction was measured centrally beneath the dressing, and at the anterior abdominal wall, before and after the application of topical negative pressures of -50, -70 and -120 mmHg. The drainage of fluid from the abdomen was measured, with and without the protective disc. Results Abdominal drainage was significantly better (p Conclusions The drainage of the open abdomen was significantly more effective when using NWPT with the protective disc than with conventional NWPT. This is believed to be due to the more even and effective pressure transduction in the open abdomen using a protective disc in combination with NPWT.

  8. Disagreement in primary study selection between systematic reviews on negative pressure wound therapy

    Directory of Open Access Journals (Sweden)

    Sauerland Stefan

    2008-06-01

    Full Text Available Abstract Background Primary study selection between systematic reviews is inconsistent, and reviews on the same topic may reach different conclusions. Our main objective was to compare systematic reviews on negative pressure wound therapy (NPWT regarding their agreement in primary study selection. Methods This retrospective analysis was conducted within the framework of a systematic review (a full review and a subsequent rapid report on NPWT prepared by the Institute for Quality and Efficiency in Health Care (IQWiG. For the IQWiG review and rapid report, 4 bibliographic databases (MEDLINE, EMBASE, The Cochrane Library, and CINAHL were searched to identify systematic reviews and primary studies on NPWT versus conventional wound therapy in patients with acute or chronic wounds. All databases were searched from inception to December 2006. For the present analysis, reviews on NPWT were classified as eligible systematic reviews if multiple sources were systematically searched and the search strategy was documented. To ensure comparability between reviews, only reviews published in or after December 2004 and only studies published before June 2004 were considered. Eligible reviews were compared in respect of the methodology applied and the selection of primary studies. Results A total of 5 systematic reviews (including the IQWiG review and 16 primary studies were analysed. The reviews included between 4 and 13 primary studies published before June 2004. Two reviews considered only randomised controlled trials (RCTs. Three reviews considered both RCTs and non-RCTs. The overall agreement in study selection between reviews was 96% for RCTs (24 of 25 options and 57% for non-RCTs (12 of 21 options. Due to considerable disagreement in the citation and selection of non-RCTs, we contacted the review authors for clarification (this was not initially planned; all authors or institutions responded. According to published information and the additional

  9. Negative pressure wound therapy in preseptal orbital cellulitis complicated with necrotizing fasciitis and preseptal abscess.

    Science.gov (United States)

    Contreras-Ruiz, José; Ramos-Cadena, Angeles; Solis-Arias, Patricia; Lozano-Platonoff, Adriana; Lopez-García, Lirio A; Contreras-Barrera, Martha E; Saenz-Corral, Claudia; de-la-Cruz-Garcia, Isabel; Cárdenas-Mejía, Alexander; Lopez-Oliver, Rubén

    2015-01-01

    Preseptal cellulitis (PC) may be locally complicated with abscess formation and necrotizing fasciitis. If not treated promptly and adequately, it may result in further complications. The authors report a series of patients where negative pressure wound therapy (NPWT) proved a safe and valuable adjunct therapy in avoiding complications of PC and in accelerating wound healing. A 4 patient case series. Four male patients (11 months to 58 years old) with unilateral complicated PC. Patients were admitted with PC and treated initially with specific intravenous antibiotic therapy. These patients did not respond adequately; therefore, surgical drainage and/or debridement were performed. After surgery, persistent edema and purulent discharge was observed prompting the need for adjunct NPWT every 48 to 72 hours. NPWT is the use of vacuum through a wound filler material covered with an airtight drape connected to a pump. Complete ophthalmologic examination was performed after each 48-hour cycle. Length of hospital stay, days from surgery to discharge, days from start of NPWT to discharge, clinical improvement, and safety. Four patients were diagnosed with PC between 2 and 5 days of evolution. Two diabetic adults developed the condition secondary to trauma, the adolescent as a result of a cosmetic piercing, and the infant associated to sinusitis. NPWT reached -125 mm·Hg, except for the infant who received -75 mm·Hg. The average number of days necessary for improvement with NPWT was 6.7 days. Only 2 patients required surgical reconstruction. Time from debridement to discharge was in average 13.5 days. No ocular complications were observed, and follow up was satisfactory with normal eyelid function and aesthetics and preserved visual acuity. NPWT proved to be safe and effective for treating locally complicated PC as an adjuvant therapy to antibiotic and surgical treatment that decreased the length of hospital stay, and the time for recovery in patients that were slow

  10. Comparison of health care costs and hospital readmission rates associated with negative pressure wound therapies.

    Science.gov (United States)

    Law, Amy; Cyhaniuk, Anissa; Krebs, Blake

    2015-03-01

    A retrospective national claims database analysis evaluated total and wound-related costs (eg, hospital readmission rates) for patients with chronic wounds treated with negative pressure wound therapy (NPWT), comparing NPWT-V (V.A.C. Therapy, KCI, an Acelity company, San Antonio, TX) and NPWT-O (other non-KCI models of NPWT, the brands of which were not known to the researchers). Patients with ≥ 1 NPWT claim from January 2009-June 2012 in outpatient settings in the United States were included, if they had continuous medical and pharmacy benefits for 12 months before the initial index date of their NPWT claim and at least 3 months post index. Mean total health care costs were assessed at 3 months and 12 months; wound-related hospital readmission rates were assessed at 3 months and 6 months. Cost differences between cohorts were analyzed by t test and readmission rates were analyzed by chi-square test. At 3 months, the cohort of NPWT-V patients was significantly younger (59.2 vs 63.6 years, P assessment, mean comorbidity scores did not differ between the NPWT-V group and the NPWT-O groups (3.38 vs 3.66). Total costs were lower for NPWT-V vs NPWT-O at 3 months ($35,498 vs $39,722, respectively; P = 0.08) and 12 months ($80,768 vs $111,212; P = 0.03). Significantly lower inpatient (P = 0.01), emergency room (P Wound-related readmission rates were significantly lower for NPWT-V at 3 months (5% vs 8%; P ≤ 0.01) and 6 months (6% vs 11%; P ≤ 0.01). For all wound types, NPWT-O patients had a 17-fold higher rate of switching to alternate NPWT models compared with NPWT-V patients. In this retrospective analysis, NPWT-V patients had lower total costs, lower wound-related costs, and lower hospital readmission rates than NPWT-O patients at all time points assessed.

  11. Cost analysis of Topical Negative Pressure (TNP Therapy for traumatic acquired wounds

    Directory of Open Access Journals (Sweden)

    Freytag, Sebastian

    2010-01-01

    Full Text Available Extended traumatic wounds require extended reconstructive operations and are accompanied by long hospitalizations and risks of infection, thrombosis and flap loss. In particular, the frequently used Topical Negative Pressure (TNP Therapy is regarded as cost-intensive. The costs of TNP in the context of traumatic wounds is analyzed using the method of health economic evaluation.All patients (n=67: 45 male, 22 female; average age 54 y with traumatically acquired wounds being treated with TNP at the university hospital of Goettingen in the period 01/01/2005–31/12/2007 comprise the basis for this analysis. The concept of activity-based costing based on clinical pathways according to InEK (National Institute for the Hospital Remuneration System systematic calculations was chosen for cost accounting. In addition, a special module system adaptable for individual courses of disease was developed. The treated wounds were located on a lower extremity in 83.7% of cases (n=56 and on an upper extremity in 16.3% of cases (n=11. The average time of hospitalization of the patients was 54 days. Twenty-five patients (37.31% exceeded the „maximum length of stay“ of their associated DRG (Diagnosis Related Groups. The total PCCL (patient clinical complexity level = patient severity score of 2.99 reflects the seriousness of disease. For the treatment of the 67 patients, total costs were $1,729,922.32 (1,249,176.91 €. The cost calculation showed a financial deficit of $–210,932.50 (–152,314.36 €. Within the entire treatment costs of $218,848.07 (158,030.19 €, 12.65% per case were created by TNP with material costs of $102,528.74 (74,036 €, representing 5.92% of entire costs. The cost of TNP per patient averaged $3,266.39 (2,358.66 €. The main portion of the costs was not – as is often expected – due to high material costs of TNP but instead to long-term treatments. Because of their complexity, the cases are insufficiently represented in the

  12. Insomnia complaints in lean patients with obstructive sleep apnea negatively affect positive airway pressure treatment adherence.

    Science.gov (United States)

    Eysteinsdottir, Bjorg; Gislason, Thorarinn; Pack, Allan I; Benediktsdottir, Bryndís; Arnardottir, Erna S; Kuna, Samuel T; Björnsdottir, Erla

    2017-04-01

    The objective of this study was to evaluate the determinants of long-term adherence to positive airway pressure treatment among patients with obstructive sleep apnea, with special emphasis on patients who stop positive airway pressure treatment within 1 year. This is a prospective long-term follow-up of subjects in the Icelandic Sleep Apnea Cohort who were diagnosed with obstructive sleep apnea between 2005 and 2009, and started on positive airway pressure treatment. In October 2014, positive airway pressure adherence was obtained by systematically evaluating available clinical files (n = 796; 644 males, 152 females) with moderate to severe obstructive sleep apnea (apnea-hypopnea index ≥15 events per h). The mean follow-up time was 6.7 ± 1.2 years. In total, 123 subjects (15.5%) returned their positive airway pressure device within the first year, 170 (21.4%) returned it later and 503 (63.2%) were still using positive airway pressure. The quitters within the first year had lower body mass index, milder obstructive sleep apnea, less sleepiness, and more often had symptoms of initial and late insomnia compared with long-term positive airway pressure users at baseline. Both initial and late insomnia were after adjustment still significantly associated with being an early quitter among subjects with body mass index insomnia are associated with early quitting on positive airway pressure among non-obese subjects. © 2016 European Sleep Research Society.

  13. Circulatory responses to lower body negative pressure in young Afghans and Danes

    DEFF Research Database (Denmark)

    Asmar, Ali; Bülow, Jens; Simonsen, Lene

    2014-01-01

    PURPOSE: We have previously shown that Afghans residing in Denmark for at least 12 years exhibit a lower 24-h ambulatory blood pressure compared to Danes. The purpose of this study was to test the hypothesis that the lower blood pressure reflects attenuated compensatory baroreflex responses...

  14. The use of a rigid disc to protect exposed structures in wounds treated with negative pressure wound therapy: effects on wound bed pressure and microvascular blood flow.

    Science.gov (United States)

    Anesäter, Erik; Borgquist, Ola; Torbrand, Christian; Roupé, K Markus; Ingemansson, Richard; Lindstedt, Sandra; Malmsjö, Malin

    2012-01-01

    There are increasing reports of deaths and serious complications associated with the use of negative pressure wound therapy (NPWT). Bleeding may occur in patients when NPWT is applied to a wound with exposed blood vessels or vascular grafts, possibly due to mechanical deformation and hypoperfusion of the vessel walls. Recent evidence suggests that using a rigid barrier disc to protect underlying tissue can prevent this mechanical deformation. The aim of this study was to examine the effect of rigid discs on the tissue exposed to negative pressure with regard to tissue pressure and microvascular blood flow. Peripheral wounds were created on the backs of eight pigs. The pressure and microvascular blood flow in the wound bed were measured when NPWT was applied. The wound was filled with foam, and rigid discs of different designs were inserted between the wound bed and the foam. The discs were created with or without channels (to accommodate exposed sensitive structures such as blood vessels and nerves), perforations, or a porous dressing that covered the underside of the discs (to facilitate pressure transduction and fluid evacuation). When comparing the results for pressure transduction to the wound bed, no significant differences were found using different discs covered with dressing, whereas pressure transduction was lower with bare discs. Microvascular blood flow in the wound bed decreased by 49 ± 7% when NPWT was applied to control wounds. The reduction in blood flow was less in the presence of a protective disc (e.g., -6 ± 5% for a dressing-covered, perforated disc, p = 0.006). In conclusion, NPWT causes hypoperfusion of superficial tissue in the wound bed. The insertion of a rigid barrier counteracts this effect. The placement of a rigid disc over exposed blood vessels or nerves may protect these structures from rupture and damage. © 2012 by the Wound Healing Society.

  15. Use of dynamic CT in acute respiratory distress syndrome (ARDS) with comparison of positive and negative pressure ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Helm, Emma; Babyn, Paul [Hospital for Sick Children, Department of Diagnostic Imaging, Toronto (Canada); Talakoub, Omid; Alirezaie, Javad [Ryerson University, Department of Electrical and Computer Engineering, Toronto, ON (Canada); Grasso, Francesco; Engelberts, Doreen; Kavanagh, Brian P. [Hospital for Sick Children and the University of Toronto, Departments of Anesthesia and Critical Care Medicine and the Program in Pulmonary and Experimental Medicine, Toronto (Canada)

    2009-01-15

    Negative pressure ventilation via an external device ('iron lung') has the potential to provide better oxygenation with reduced barotrauma in patients with ARDS. This study was designed to see if oxygenation differences between positive and negative ventilation could be explained by CT. Six anaesthetized rabbits had ARDS induced by repeated saline lavage. Rabbits were ventilated with positive pressure ventilation (PPV) and negative pressure ventilation (NPV) in turn. Dynamic CT images were acquired over the respiratory cycle. A computer-aided method was used to segment the lung and calculate the range of CT densities within each slice. Volumes of ventilated lung and atelectatic lung were measured over the respiratory cycle. NPV was associated with an increased percentage of ventilated lung and decreased percentage of atelectatic lung. The most significant differences in ventilation and atelectasis were seen at mid-inspiration and mid-expiration (ventilated lung NPV=61%, ventilated lung PPV=47%, p<0.001; atelectatic lung NPV=10%, atelectatic lung PPV 19%, p<0.001). Aeration differences were not significant at end-inspiration. Dynamic CT can show differences in lung aeration between positive and negative ventilation in ARDS. These differences would not be appreciated if only static breath-hold CT was used. (orig.)

  16. Effects of topical negative pressure therapy on tissue oxygenation and wound healing in vascular foot wounds.

    Science.gov (United States)

    Chiang, Nathaniel; Rodda, Odette A; Sleigh, Jamie; Vasudevan, Thodur

    2017-08-01

    Topical negative pressure (TNP) therapy is widely used in the treatment of acute wounds in vascular patients on the basis of proposed multifactorial benefits. However, numerous recent systematic reviews have concluded that there is inadequate evidence to support its benefits at a scientific level. This study evaluated the changes in wound volume, surface area, depth, collagen deposition, and tissue oxygenation when using TNP therapy compared with traditional dressings in patients with acute high-risk foot wounds. This study was performed with hospitalized vascular patients. Forty-eight patients were selected with an acute lower extremity wound after surgical débridement or minor amputation that had an adequate blood supply without requiring further surgical revascularization and were deemed suitable for TNP therapy. The 22 patients who completed the study were randomly allocated to a treatment group receiving TNP or to a control group receiving regular topical dressings. Wound volume and wound oxygenation were analyzed using a modern stereophotographic wound measurement system and a hyperspectral transcutaneous oxygenation measurement system, respectively. Laboratory analysis was conducted on wound biopsy samples to determine hydroxyproline levels, a surrogate marker to collagen. Differences in clinical or demographic characteristics or in the location of the foot wounds were not significant between the two groups. All patients, with the exception of two, had diabetes. The two patients who did not have diabetes had end-stage renal failure. There was no significance in the primary outcome of wound volume reduction between TNP and control patients on day 14 (44.2% and 20.9%, respectively; P = .15). Analyses of secondary outcomes showed a significant result of better healing rates in the TNP group by demonstrating a reduction in maximum wound depth at day 14 (36.0% TNP vs 17.6% control; P = .03). No significant findings were found for the other outcomes of changes

  17. Suction device for epidermal grafting in vitiligo: employing a syringe and a manometer to provide an adequate negative pressure.

    Science.gov (United States)

    Kim, H U; Yun, S K

    2000-07-01

    Suction devices for epidermal grafting need a suction pump to provide a negative pressure. The authors have developed a suction device in which a syringe and a manometer are employed to provide a negative pressure. The purpose of this study was to evaluate the efficacy of our suction device in vitiligo patients. The suction device was used to obtain epidermal blisters from the donor site. A CO2 laser was employed to remove the depigmented epidermis. The blister roofs of the donor site were harvested and were placed onto the recipient area. Ten patients with stable vitiligo were treated by epidermal grafting. Epidermal blisters were produced by suction in all patients. Also, all 10 patients regained repigmentation. Our suction blister device is simple and inexpensive to make, and it may become an alternative to the other suction devices.

  18. Effects of vacusac in intermittent claudication

    DEFF Research Database (Denmark)

    Himmelstrup, H; Himmelstrup, Bodil; Mehlsen, J

    1991-01-01

    The effect of a new physical treatment modality, Vacusac, was tested on a group of patients with stable intermittent claudication. Twenty-two patients with a median age of 65 years and a median duration of intermittent claudication of 5 years were randomized to either active or placebo treatments....... Seventeen patients completed the study. The effect of treatment was quantified by measurements of systemic and peripheral systolic blood pressures and by measurements of the pain-free and the maximal walking distance on a treadmill. The ankle pressure index (ankle systolic pressure/arm systolic pressure......) and toe pressure index (toe systolic pressure/arm systolic pressure) were calculated. After 25 active treatments, administered over a period of 2 months, the patients allocated to this group attained a significant increase in the pain-free walking distance from 54 m (24-107 m) to 99 m (30-420 m) (P less...

  19. Comparison of Outcomes for Normal Saline and an Antiseptic Solution for Negative-Pressure Wound Therapy with Instillation.

    Science.gov (United States)

    Kim, Paul J; Attinger, Christopher E; Oliver, Noah; Garwood, Caitlin; Evans, Karen K; Steinberg, John S; Lavery, Larry A

    2015-11-01

    Negative-pressure wound therapy with instillation is an adjunctive treatment that uses periodic instillation of a solution and negative pressure for a wide diversity of wounds. A variety of solutions have been reported, with topical antiseptics as the most frequently chosen option. The objective of this study was to compare the outcomes of normal saline versus an antiseptic solution for negative-pressure wound therapy with instillation for the adjunctive treatment of infected wounds. This was a prospective, randomized, effectiveness study comparing 0.9% normal saline versus 0.1% polyhexanide plus 0.1% betaine for the adjunctive treatment of infected wounds that required hospital admission and operative débridement. One hundred twenty-three patients were eligible, with 100 patients randomized for the intention-to-treat analysis and 83 patients for the per-protocol analysis. The surrogate outcomes measured were number of operative visits, length of hospital stay, time to final surgical procedure, proportion of closed or covered wounds, and proportion of wounds that remained closed or covered at the 30-day follow-up. There were no statistically significant differences in the demographic profiles in the two cohorts except for a larger proportion of male patients (p = 0.004). There was no statistically significant difference in the surrogate outcomes with the exception of the time to final surgical procedure favoring normal saline (p = 0.038). The authors' results suggest that 0.9% normal saline may be as effective as an antiseptic (0.1% polyhexanide plus 0.1% betaine) for negative-pressure wound therapy with instillation for the adjunctive inpatient management of infected wounds. Therapeutic, II.

  20. Wound care in patients after median sternotomy by use of negative pressure dressing - Prevena Incision Management System and PICO system

    OpenAIRE

    Sevyan, Armen

    2016-01-01

    The negative pressure wound dressing is applied successfully for the prevention of wound complications after median sternotomy in obese patients with a high risk for this complication. Most wound infections are caused by skin flora. In the market are available various systems for the prevention of wound infection. We had to compare the objective of the influence of PICO dressing and Prevena dressing on wound healing in patients after conventional median sternotomy. In this cohort study 272...

  1. Evaluation of a Decision-Making Curriculum for Teaching Adolescents with Disabilities to Resist Negative Peer Pressure.

    Science.gov (United States)

    Khemka, Ishita; Hickson, Linda; Mallory, Sarah B

    2016-07-01

    This study was designed to assess the impact of a decision-making curriculum (PEER-DM) on the social peer relationship knowledge and self-protective decision-making skills of adolescents with disabilities in hypothetical situations involving negative peer pressure. A randomized design was used to assign students with disabilities from self-contained special education classes to an intervention group (n = 22) or a wait-list control group (n = 20). ANCOVA analyses, using pretest scores as covariates, indicated that students who were trained on PEER-DM had significantly higher effective decision-making action and correct risk perception scores, relative to participants in the control group. This study provides supporting evidence that PEER-DM is a promising intervention for students with disabilities, including those with identified autism spectrum disorders, during transition years to help them develop a better understanding of positive and negative peer relationships and learn systematic decision-making skills for improved handling of social situations in the school and community, especially situations involving negative peer pressure. The study adds credence to using systematic, strategy-based decision making interventions designed to address the cognitive, emotional and motivational processes underlying adolescent decision making in sensitive interpersonal situations involving peer pressure. The study points to the lack of preparedness to handle situations of negative peer pressure as a serious social and health risk for adolescents with disabilities that deserves urgent and concerted attention in transition services programming. Implications for future curriculum-development efforts and replication of treatment findings are discussed. Future research examining disability-specific patterns of decision-making in peer situations and comparisons with typically developing populations is recommended.

  2. A direct method for determining complete positive and negative capillary pressure curves for reservoir rock using the centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Spinler, E.A.; Baldwin, B.A. [Phillips Petroleum Co., Bartlesville, OK (United States)

    1997-08-01

    A method is being developed for direct experimental determination of capillary pressure curves from saturation distributions produced during centrifuging fluids in a rock plug. A free water level is positioned along the length of the plugs to enable simultaneous determination of both positive and negative capillary pressures. Octadecane as the oil phase is solidified by temperature reduction while centrifuging to prevent fluid redistribution upon removal from the centrifuge. The water saturation is then measured via magnetic resonance imaging. The saturation profile within the plug and the calculation of pressures for each point of the saturation profile allows for a complete capillary pressure curve to be determined from one experiment. Centrifuging under oil with a free water level into a 100 percent water saturated plug results in the development of a primary drainage capillary pressure curve. Centrifuging similarly at an initial water saturation in the plug results in the development of an imbibition capillary pressure curve. Examples of these measurements are presented for Berea sandstone and chalk rocks.

  3. Negative pressures in full-scale distribution system: field investigation, modelling, estimation of intrusion volumes and risk for public health

    Directory of Open Access Journals (Sweden)

    M. C. Besner

    2010-07-01

    Full Text Available Various investigations encompassing microbial characterization of external sources of contamination (soil and trenchwater surrounding water mains, flooded air-valve vaults, field pressure monitoring, and hydraulic and transient analyses were conducted in the same distribution system where two epidemiological studies showing an increase in gastrointestinal illness for people drinking tap water were conducted in the 1990's. Interesting results include the detection of microorganisms indicators of fecal contamination in all external sources investigated but at a higher frequency in the water from flooded air-valve vaults, and the recording of 18 negative pressure events in the distribution system during a 17-month monitoring period. Transient analysis of this large and complex distribution system was challenging and highlighted the need to consider field pressure data in the process.

  4. Intermittent Explosive Disorder

    OpenAIRE

    Lut Tamam; Meliha Zengin Eroglu; Ozlem Paltaci

    2011-01-01

    Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etio...

  5. The Ambivalence of Challenge Stressors: Time Pressure Associated with Both Negative and Positive Well-Being

    Science.gov (United States)

    Widmer, Pascale S.; Semmer, Norbert K.; Kalin, Wolfgang; Jacobshagen, Nicola; Meier, Laurenz L.

    2012-01-01

    According to the challenge-hindrance model, challenge stressors contain both stressful and challenging aspects, hindrance stressors only stressful aspects. Typically, negative outcomes of challenge stressors refer to well-being (strain), positive outcomes to so-called work outcomes (e.g., productivity, intention to quit). As both effects occur…

  6. Perceiving social pressure not to feel negative predicts depressive symptoms in daily life

    NARCIS (Netherlands)

    Dejonckheere, E.; Bastian, B.; Fried, E.I.; Murphy, S.C.; Kuppens, P.

    Background Western societies often overemphasize the pursuit of happiness, and regard negative feelings such as sadness or anxiety as maladaptive and unwanted. Despite this emphasis on happiness, the amount of people suffering from depressive complaints is remarkably high. To explain this apparent

  7. Proneness to worry is negatively associated with blood pressure and baroreflex sensitivity: further evidence of the blood pressure emotional dampening hypothesis.

    Science.gov (United States)

    Delgado, Luis Carlos; Vila, Jaime; Reyes del Paso, Gustavo A

    2014-02-01

    This study analyzes differences in blood pressure (BP) and baroreflex sensitivity (BRS) in relation to trait worry. 36 high worry and 21 low worry females were selected from scores on the Penn State Worry Questionnaire. Cardiovascular parameters were obtained during rest, a self-induced worry period, and defense reflex to intense auditory stimulation. Low worry participants exhibited greater BP during baseline and greater BRS both during baseline and the self-induced worry period than high worry participants. During the defense reflex, low worries present a greater increase in BP. It is concluded that low proneness to worry is associated with greater BP and BRS. Increases in BP during aversive stimulation activated a negative feedback mechanism to inhibit distress and emotional reactivity to negative stimulation. These results support the BP-emotional dampening hypothesis and suggest that the baroreflex can be a relevant mechanism in mediating this effect. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Negative pressure of the environmental air in the cleaning area of the materials and sterilization center: a systematic review

    Directory of Open Access Journals (Sweden)

    Caroline Lopes Ciofi-Silva

    Full Text Available ABSTRACT Objective: to analyze the scientific evidence on aerosols generated during cleaning activities of health products in the Central Service Department (CSD and the impact of the negative pressure of the ambient air in the cleaning area to control the dispersion of aerosols to adjacent areas. Method: for this literature systematic review the following searches were done: search guidelines, manuals or national and international technical standards given by experts; search in the portal and databases PubMed, Scopus, CINAHL and Web of Science; and a manual search of scientific articles. Results: the five technical documents reviewed recommend that the CSD cleaning area should have a negative differential ambient air pressure, but scientific articles on the impact of this intervention were not found. The four articles included talked about aerosols formed after the use of a ultrasonic cleaner (an increased in the contamination especially during use and pressurized water jet (formation of smaller aerosols 5μm. In a study, the aerosols formed from contaminated the hot tap water with Legionella pneumophila were evaluated. Conclusions: there is evidence of aerosol formation during cleanup activities in CSD. Studies on occupational diseases of respiratory origin of workers who work in CSD should be performed.

  9. The Influence of the Bed with a Semiopen Hood on Bacteria Removal in a Negative-Pressure Isolation Room

    Directory of Open Access Journals (Sweden)

    Jeng-Min Huang

    2014-06-01

    Full Text Available This study numerically investigates the influence of a sickbed with a semiopened hood on bacteria removal in a negative-pressure isolation room. The parameters include air change rate, lying style, the length and height of hood, flow rate allotments, and the positions of outlets. The results show that the hood has excellent effect on the removal of contaminated air, which is much better than the case without hood. The flow field of patient's face up cough is very different from face side cough, and the contaminated air cannot be removed properly through one air outlet. There are three outlets on the hood, set straight above the patient's face and at both sides. The allotment of the exhaust flow rate of the upper outlet to that of side outlets is suggested to be 4: 6. When the total air change rate is above 6 ACH, the hood length has slight influence on pollutant removal. The increase of hood height has a negative impact when the patient coughs lying on back. When the side exhaust flow rate is high, the hood height has a slight impact for face side cough. The recommended air change rate for the negative-pressure ward with sickbed hood is above 5 ACH.

  10. Comparisons of negative pressure wound therapy and ultrasonic debridement for diabetic foot ulcers: a network meta-analysis.

    Science.gov (United States)

    Wang, Ruran; Feng, Yanhua; Di, Bo

    2015-01-01

    a network meta-analysis was performed to compare the strength and weakness of negative pressure wound therapy (NPWT) with ultrasound debridement (UD) as for diabetic foot ulcers (DFU). PubMed, Ovid EMBASE, Web of Science, Cochrane library databases, and Chinese Biomedical Literature Database were searched till February 2015. Clinical compared studies of negative pressure wound therapy and ultrasound debridement were enrolled. The primary efficacy outcomes included healed ulcers, reduction of ulcer areas and time to closure. Secondary amputation including major and minor amputations was used to assess the safety profile. Out of 715 studies, 32 were selected which enrolled 2880 diabetic patients. The pooled analysis revealed that NPWT including vacuum assisted closure (VAC) and vacuum sealing drainage (VSD) were as efficacious as ultrasound debridement improving healed ulcers, odds ratio, 0.86; 95% CI 0.28 to 2.6 and 1.2; 95% CI 0.38 to 4, respectively. However, both were better to standard wound care in wound healing patients. Compared with the standard wound care treated diabetic foot ulcers, NPWT and UD resulted in a significantly superior efficacy in time to wound closure and decrement in area of wound. No significances were observed between NPWT and UD groups in both indicators. Fewer patients tended to receive amputation in NPWT and UD groups compared to standard wound care group. The results of the network meta-analysis indicated that negative pressure wound therapy was similar to ultrasound debridement for diabetic foot ulcers, but better than standard wound care both in efficacy and safety profile.

  11. Comparisons of negative pressure wound therapy and ultrasonic debridement for diabetic foot ulcers: a network meta-analysis

    Science.gov (United States)

    Wang, Ruran; Feng, Yanhua; Di, Bo

    2015-01-01

    Objective: a network meta-analysis was performed to compare the strength and weakness of negative pressure wound therapy (NPWT) with ultrasound debridement (UD) as for diabetic foot ulcers (DFU). Methods: PubMed, Ovid EMBASE, Web of Science, Cochrane library databases, and Chinese Biomedical Literature Database were searched till February 2015. Clinical compared studies of negative pressure wound therapy and ultrasound debridement were enrolled. The primary efficacy outcomes included healed ulcers, reduction of ulcer areas and time to closure. Secondary amputation including major and minor amputations was used to assess the safety profile. Results: Out of 715 studies, 32 were selected which enrolled 2880 diabetic patients. The pooled analysis revealed that NPWT including vacuum assisted closure (VAC) and vacuum sealing drainage (VSD) were as efficacious as ultrasound debridement improving healed ulcers, odds ratio, 0.86; 95% CI 0.28 to 2.6 and 1.2; 95% CI 0.38 to 4, respectively. However, both were better to standard wound care in wound healing patients. Compared with the standard wound care treated diabetic foot ulcers, NPWT and UD resulted in a significantly superior efficacy in time to wound closure and decrement in area of wound. No significances were observed between NPWT and UD groups in both indicators. Fewer patients tended to receive amputation in NPWT and UD groups compared to standard wound care group. Conclusions: The results of the network meta-analysis indicated that negative pressure wound therapy was similar to ultrasound debridement for diabetic foot ulcers, but better than standard wound care both in efficacy and safety profile. PMID:26550165

  12. Negative Pressure Wound Therapy in Infected Wound following Posterior Spinal Instrumentation using Simple Self-assembled System: A Case Report

    Directory of Open Access Journals (Sweden)

    CW Chang

    2014-07-01

    Full Text Available Postoperative wound infection in an instrumented spine patient is often disastrous. Management includes implant removal leading to spine instability. Negative pressure wound therapy (NPWT applied to the spine surgical wound is one of the wound care technique with successful results. We report a case of a man who sustained Chance fracture of Lumbar 1 (L1 vertebra treated with long segment posterior instrumentation, who unfortunately developed Extended-spectrum beta-lactamase (ESBL positive E. coli infection one month after the operation. After careful debridement of the wound, the implant became exposed. Three cycles of NPWT were applied and the wound healed with granulation tissue completely covering the implant, and thus negating the need to remove the implant. In conclusion, the NPWT is a good alternative in postoperative wound management especially in an instrumented spine patient.

  13. Comparison of two negative pressure systems and syringe irrigation for root canal irrigation: an ex vivo study.

    Science.gov (United States)

    Adorno, C G; Fretes, V R; Ortiz, C P; Mereles, R; Sosa, V; Yubero, M F; Escobar, P M; Heilborn, C

    2016-02-01

    To compare in a laboratory study two negative pressure systems and syringe irrigation, regarding the delivery of a contrast solution (CS) to working length (WL) and into simulated lateral canals and the effective volume of irrigant aspirated during negative pressure irrigation. Twenty single-canaled incisor training models were constructed with six simulated lateral canals each (2, 4 and 6 mm to WL) and a size 40, 0.04 taper apical size canal. Each model underwent all irrigation procedures (EndoVac at WL (EndoVac-0) and WL-2 mm (EndoVac-2), iNP needle with negative pressure (iNPn) and syringe irrigation with the iNP needle (iNPs) and a 30-G side-slot needle placed at WL (SI0) and WL-2 (SI2) mm in a crossover design. CS was delivered at 4 mL min(-1) for 60 s with a peristaltic pump and a recovery device collected the volume (in mL) of irrigant suctioned by the negative pressure groups. The irrigation procedures were digitally recorded, and a still image of the 60-s time-point of irrigation was evaluated for CS distance to WL (in millimetres) after irrigation and penetration into lateral canals (3-point scale). Statistical tests used were Kruskal-Wallis and Dunn's test. EndoVac-0, iNPn and iNPs had median distances of CS to WL of 0 mm, followed by SI0 (0.2 mm), SI2 (0.7 mm) and EndoVac-2 (1.7 mm). There were no significant differences between EndoVac-0, iNPn, iNPs and SI0, but these were significantly different to SI2 and EndoVac-2 (P irrigation and that collected by iNPn (4 mL), but these were significantly greater than EndoVac-0 (2.8 mL, P irrigation procedures were ineffective at penetration into lateral canals. iNPn, EndoVac-0, iNPs and SI0 achieved greater irrigant penetration to WL. iNPn was able to collect a median volume of CS (4 mL) similar to that delivered by syringe irrigation (iNPp, SI0 and SI2). An adequate irrigant penetration into lateral canals could not be achieved by any of the systems. © 2015 International Endodontic Journal. Published by John

  14. Hemodynamic responses to seated and supine lower body negative pressure - Comparison with +Gz acceleration

    Science.gov (United States)

    Polese, Alvese; Sandler, Harold; Montgomery, Leslie D.

    1992-01-01

    The hemodynamic responses to LBNP in seated subjects and in subjects in supine body positions were compared and were correlated with hemodynamic changes which occurred during a simulated (by centrifugation) Shuttle reentry acceleration with a slow onset rate of 0.002 G/s and during gradual onset exposures to +3 Gz and +4 Gz. Results demonstrate that seated LBNP at a level of -40 mm Hg can serve as a static simulator for changes in the heart rate and in mean blood pressure induced by gradual onset acceleration stress occurring during Shuttle reentry. The findings also provide a rationale for using LBNP during weightlessness as a means of imposing G-loading on the circulation prior to reentry.

  15. A switchable positive and negative air pressure device for efficient and gentle handling of nanofiber scaffolds

    Science.gov (United States)

    Hotaling, Nathan A.; Khristov, Vladimir; Maminishkis, Arvydas; Bharti, Kapil; Simon, Carl G.

    2017-10-01

    A scaffold handling device (SHD) has been designed that can switch from gentle suction to positive pressure to lift and place nanofiber scaffolds. In tissue engineering laboratories, delicate fibrous scaffolds, such as electrospun nanofiber scaffolds, are often used as substrates for cell culture. Typical scaffold handling procedures include lifting the scaffolds, moving them from one container to another, sterilization, and loading scaffolds into cell culture plates. Using tweezers to handle the scaffolds can be slow, can damage the scaffolds, and can cause them to wrinkle or fold. Scaffolds may also acquire a static charge which makes them difficult to put down as they cling to tweezers. An SHD has been designed that enables more efficient, gentle lifting, and placement of delicate scaffolds. Most of the parts to make the SHD can be purchased, except for the tip which can be 3D-printed. The SHD enables more reliable handling of nanofiber scaffolds that may improve the consistency of biomanufacturing processes.

  16. Noninvasive tracking of systolic arterial blood pressure using pulse transit time measured with ECG and carotid doppler signals with intermittent calibration

    OpenAIRE

    Fujita, Yoshihisa

    2016-01-01

    We have developed a non-invasive blood pressure measurement system using pulse transit time (PTT) from the heart to the common carotid artery, measured by using an electrocardiogram (ECG) R-wave and carotid arterial Doppler signals at the anterior neck. In this study, we examined the validity of our system by comparing PTT derived systolic blood pressure (Dopp_SBP) with invasive radial systolic arterial pressure (Inv_SBP) with calibration every 15 min in the ICU setting.Methods: 17 patients u...

  17. Characteristics of intermittent fuel sprays

    Science.gov (United States)

    Jawad, B.; Gulari, E.; Henein, N. A.

    1992-03-01

    The spray-tip penetrations and the drop sizes of intermittent fuel sprays were measured by using a modified pulsed optical spray sizer. The average spray tip speeds were determined from simultaneously recorded needle lift signals and obscuration traces. The speeds of a sequence of fuel pulses injected at about 1000 Hz were analyzed to elucidate penetration mechanisms. A correlation that relates penetration distance to time, pressure drop across the nozzle, fuel density, and ambient gas density was obtained. The temporal variations of drop size in penetrating pulses of sprays were measured. The concentration of drops were calculated by combining drop size and obscuration data. The Sauter mean diameter of penetrating fuel drops increased with an increase of the chamber pressure and decreased with an increase of the injection pressure.

  18. Evidence-based recommendations for negative pressure wound therapy: treatment variables (pressure levels, wound filler and contact layer)--steps towards an international consensus.

    Science.gov (United States)

    Birke-Sorensen, H; Malmsjo, M; Rome, P; Hudson, D; Krug, E; Berg, L; Bruhin, A; Caravaggi, C; Chariker, M; Depoorter, M; Dowsett, C; Dunn, R; Duteille, F; Ferreira, F; Francos Martínez, J M; Grudzien, G; Ichioka, S; Ingemansson, R; Jeffery, S; Lee, C; Vig, S; Runkel, N; Martin, R; Smith, J

    2011-09-01

    Negative pressure wound therapy (NPWT) is becoming a commonplace treatment in many clinical settings. New devices and dressings are being introduced. Despite widespread adoption, there remains uncertainty regarding several aspects of NPWT use. To respond to these gaps, a global expert panel was convened to develop evidence-based recommendations describing the use of NPWT. In a previous communication, we have reviewed the evidence base for the use of NPWT within trauma and reconstructive surgery. In this communication, we present results of the assessment of evidence relating to the different NPWT treatment variables: different wound fillers (principally foam and gauze); when to use a wound contact layer; different pressure settings; and the impact of NPWT on bacterial bioburden. Evidence-based recommendations were obtained by a systematic review of the literature, grading of evidence and drafting of the recommendations by a global expert panel. Evidence and recommendations were graded according to the Scottish Intercollegiate Guidelines Network (SIGN) classification system. In general, there is relatively weak evidence on which to base recommendations for any one NPWT treatment variable over another. Overall, 14 recommendations were developed: five for the choice of wound filler and wound contact layer, four for choice of pressure setting and five for use of NPWT in infected wounds. With respect to bioburden, evidence suggests that reduction of bacteria in wounds is not a major mode of action of NPWT. Copyright © 2011 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  19. Negative pressure wound therapy with Bio-Dome dressing technology in the treatment of complex wounds: a case series.

    Science.gov (United States)

    Penny, H L; Spinazzola, J; Green, A; Rifkah, M; Faretta, M; Youshaw, D; Weaver, A; Zaki, P

    2014-04-01

    The treatment of complex wounds is difficult and not always effective. Various treatment options are used with varying degrees of success. Negative pressure wound therapy (NPWT) is a cost-efficient and effective way to help treat these wounds. The use of a vacuum device applies the negative pressure to the site of the wound and promotes waste removal and increases circulation and tissue formation. While various NPWT systems are currently on the market, we utilised the ConvaTec Engenex® system with Bio-DomeTM technology; however, our case study is not intended to advocate the specific use of this system, but instead focuses on the use of NPWT as a viable option for wound healing. Each of the following case study patients presented with difficult-to-heal wounds that failed traditional therapeutic approaches. Through the use of NPWT, our patients saw major wound size reductions. Each patient exhibited at least a 94% reduction in wound area, wound volume or both.

  20. Does Negative-Pressure Wound Therapy for the Open Abdomen Benefit the Patient? A Retrospective Cohort Study.

    Science.gov (United States)

    Krebs, Bojan; Jagrič, Tomaž

    2017-06-01

    Negative-pressure wound therapy (NPWT) is the most modern and sophisticated method of temporary abdominal closure. The aim of the study was to determine the significant predictors for mortality in patients with NPWT. University Clinical Centre Maribor, Slovenia MATERIALS AND METHODS:: The authors performed a retrospective cohort study of all patients treated with NPWT between January 1, 2011, and December 31, 2014. In the univariate analysis, the type of wound closure, more than 7 NPWT changes, the total days with NPWT, and time to wound closure were significantly associated with death of the patient. In the multivariate analysis, only the number of more than 7 NPWT changes was found as a significant predictor for death (P = .038). Negative-pressure wound therapy is a method of choice for the treatment of open abdomen if there is a clear indication. However, clinicians should try all measures to remove the NPWT system and close the abdomen as soon as possible because prolonged use is associated with significantly higher mortality.

  1. Closed-incision negative-pressure therapy in high-risk general surgery patients following laparotomy: a retrospective study.

    Science.gov (United States)

    Zaidi, A; El-Masry, S

    2017-03-01

    Surgical site infection (SSI) and wound dehiscence are dreaded complications following laparotomy in general surgical patients, and can potentially occur more often in various comorbid states. Negative-pressure wound therapy (NPWT) has a positive effect of on open and complicated wounds and so has been used for at-risk surgical incisions with the aim of redistributing lateral tension and holding incision edges together. The aim of the present study was to compare the rate of wound complications following laparotomy in high-risk general surgical patients with a clean incision treated with closed-incision negative-pressure therapy (ciNPT) with those receiving conventional care. A retrospective review was performed of the hospital medical records of patients who underwent laparotomy between 1 October 2010 and 31 March 2012. Records of 69 patients who received ciNPT and 112 who were managed by adherent gauze dressings were included in the final analysis. Two (2.9%) patients in the ciNPT group and 23 (20.5%) in the non-NPWT group developed a wound complication following laparotomy (P surgery patients considered to have risk of developing wound complications following laparotomy. © 2016 The Authors. Colorectal Disease published by John Wiley & Sons Ltd on behalf of Association of Coloproctology of Great Britain and Ireland.

  2. The efficacy of negative pressure wound therapy in the management of lower extremity trauma: review of clinical evidence.

    Science.gov (United States)

    Kanakaris, N K; Thanasas, C; Keramaris, N; Kontakis, G; Granick, Mark S; Giannoudis, P V

    2007-12-01

    A large number of aids have been conceived and introduced into clinical practice (nutritional supplements, local dressings, technical innovations) aimed at facilitating and optimising wound healing in both acute and chronic wound settings. Among these advances, negative pressure wound therapy (NPWT) has been introduced during the last 30 years, and has been analysed in over 400 manuscripts of the English, Russian and German literature. Until very recently, vacuum assisted closure (VAC) (KCI, TX, USA) has been the only readily available commercial device that provides localised negative pressure to the wound and is the predominant agent used to deliver NPWT featured in this review. We conducted a comprehensive review of the existing clinical evidence of the English literature on the applications of NPWT in the acute setting of trauma and burns of the lower extremity. Overall, 16 clinical studies have been evaluated and scrutinised as to the safety and the efficacy of this adjunct therapy in the specific environment of trauma. Effectiveness was comparable to the standard dressing and wound coverage methods. The existing clinical evidence justifies its application in lower limb injuries associated with soft tissue trauma.

  3. Measurement of negative ion mobility in O2 at high pressures using a point plate gap as an ion detector

    International Nuclear Information System (INIS)

    Okuyama, Y; Kimura, T; Suzuki, S; Itoh, H

    2012-01-01

    This paper describes the experimental results for negative ion mobility in O 2 at 0.5-2.0 atm. The ion mobility is observed using a high-pressure ion drift tube with a positive corona gap (Geiger counter), which is constructed from a point plate gap and acts as a negative ion detector. The variation of waveforms in the burst pulse is observed by varying the voltage applied to the ion detector to find the optimum voltage that must be applied across the ion detector in O 2 . This is investigated carefully to ensure the precise determination of mobility. The distortion of the electric field near the mesh electrode, which operates as the cathode of the ion detector and as the anode of the ion drift gap, is then examined to determine the optimum applied voltage to suppress its effect on the measurement of mobility. The mobility is subsequently measured at a reduced electric field intensity of 2.83 × 10 -3 to 2.83. The observed mobility of 2.31 ± 0.03 cm 2 V -1 s -1 in O 2 is concluded to be that of O 2 - . This value is also obtained in experiments over a wide range of gas pressures (0.5-2.0 atm) and drift lengths (1.00-9.00 cm). The mobilities of O 3 - and O - are also obtained experimentally. (paper)

  4. [Efficacy observation on application of negative pressure therapy in the treatment of superficial partial-thickness scald wound in children].

    Science.gov (United States)

    Shen, Chuan-an; Chai, Jia-ke; Tuo, Xiao-ye; Cai, Jian-hua; Li, Dong-jie; Zhang, Lin; Zhu, Hua; Cai, Jin-dong

    2013-02-01

    To observe the effect of negative pressure therapy in the treatment of superficial partial-thickness scald in children. Three hundred and seven children with superficial partial-thickness scald hospitalized from August 2009 to May 2012 were divided into negative pressure therapy group (NPT, n = 145) and control group (C, n = 162) according to the random number table. Patients in group NPT were treated with negative pressure from within post injury day (PID) 3 to PID 9 (with -16 kPa pressure), while traditional occlusive dressing method was used in group C. Changes in body temperature, wound healing condition, frequency of dressing change were compared between group NPT and group C. Bacterial culture results of wounds were compared before and after treatment in group NPT. Volume of drained transudate per one percent of wound area was recorded in group NPT on PID 1 to PID 3. Data were processed with t test or chi-square test. The incidence of high fever was significantly lower in group NPT (26.9%, 39/145) than in group C (63.6%, 103/162, χ(2) = 41.419, P wound epithelization was observed in 138 patients in group NPT, and in 7 patients there were a few residual wounds which healed after dressing change for 2 days. The wound healing time of patients in group NPT [(9.2 ± 0.6) d] was obviously shorter than that in group C [(10.1 ± 1.6) d, t = 6.895, P wound secretion of seventeen patients in group NPT before treatment, while no bacterium was discovered in all patients after treatment. Volumes of drainage fluid in group NPT were proportional to wound areas, which were respectively (9.8 ± 3.2), (6.2 ± 2.1), (4.1 ± 1.6) mL per one percent of wound area on PID 1, 2, and 3. NPT can decrease times of dressing change, and alleviate infection and inflammatory response by drainage of transudate, which promotes wound healing at last. NPT is proved to be a safe and effective approach for treatment of children with superficial partial-thickness scald.

  5. [Mode of debridement, negative-pressure therapy combined with tissue transplantation for treatment of complicated and refractory wounds].

    Science.gov (United States)

    Lei, Jin; Li, Hu-shan; Hao, Zhen-ming; Duan, Peng; Hao, Wen-jie

    2011-12-01

    To observe therapeutic effect of negative-pressure treatment combined with tissue transplantation on complicated and refractory wounds after debridement. After debridement, 20 patients with 20 complicated and refractory wounds hospitalized in our burn wards from May 2008 to June 2010 were randomly divided into treatment group (T, treated with negative-pressure from -19 kPa to -8 kPa, n = 10) and control group (C, covered with petrolatum gauze overlaid with saline gauze and dry gauze, n = 10) according to alternating method. On post treatment day (PTD) 4, 7, and 14, granulation tissues of wound surface in size of 4 mm × 3 mm × 2 mm were harvested for histopathological observation (including capillary growth, inflammatory cells, and collagen arrangement) with HE staining, and the numbers of vascular endothelial cells (VEC, with addition of rabbit anti-human coagulation factor VIII related antigen polyclonal antibody) and proliferation period cells (with addition of mouse anti-human Ki-67 monoclonal antibody) were counted by immunohistochemical staining. Data were processed with t test. Another 59 patients harboring 62 complicated and refractory wounds admitted to our burn ward at the same period were treated with the same mode of debridement, negative-pressure therapy, followed by timely skin or skin flap grafting. (1) Granulation tissue in T group grew more rapidly than that in C group. More capillaries and less inflammatory cells were observed in T group on PTD 7 as compared with those in C group. Collagen in T group on PTD 14 was more regular in arrangement than that in C group. The number of VEC per 400 times visual field in T group on PTD 4, 7, and 14 was respectively higher than that in C group (108.7 ± 11.2 vs. 31.0 ± 3.6, 138.0 ± 14.7 vs. 34.6 ± 4.5, 68.7 ± 6.9 vs. 55.1 ± 6.5, with t values from 4.62 to 30.28, P values all equal to 0.01). The number of proliferation period cell per 400 times visual field in T group on PTD 4 and 7 was respectively

  6. Effect of Negative Pressure on Proliferation, Virulence Factor Secretion, Biofilm Formation, and Virulence-Regulated Gene Expression of Pseudomonas aeruginosa In Vitro

    Directory of Open Access Journals (Sweden)

    Guo-Qi Wang

    2016-01-01

    Full Text Available Objective. To investigate the effect of negative pressure conditions induced by NPWT on P. aeruginosa. Methods. P. aeruginosa was cultured in a Luria–Bertani medium at negative pressure of −125 mmHg for 24 h in the experimental group and at atmospheric pressure in the control group. The diameters of the colonies of P. aeruginosa were measured after 24 h. ELISA kit, orcinol method, and elastin-Congo red assay were used to quantify the virulence factors. Biofilm formation was observed by staining with Alexa Fluor® 647 conjugate of concanavalin A (Con A. Virulence-regulated genes were determined by quantitative RT-PCR. Results. As compared with the control group, growth of P. aeruginosa was inhibited by negative pressure. The colony size under negative pressure was significantly smaller in the experimental group than that in the controls (p<0.01. Besides, reductions in the total amount of virulence factors were observed in the negative pressure group, including exotoxin A, rhamnolipid, and elastase. RT-PCR results revealed a significant inhibition in the expression level of virulence-regulated genes. Conclusion. Negative pressure could significantly inhibit the growth of P. aeruginosa. It led to a decrease in the virulence factor secretion, biofilm formation, and a reduction in the expression level of virulence-regulated genes.

  7. The Key Roles of Negative Pressure Breathing and Exercise in the Development of Interstitial Pulmonary Edema in Professional Male SCUBA Divers.

    Science.gov (United States)

    Castagna, Olivier; Regnard, Jacques; Gempp, Emmanuel; Louge, Pierre; Brocq, François Xavier; Schmid, Bruno; Desruelle, Anne-Virginie; Crunel, Valentin; Maurin, Adrien; Chopard, Romain; MacIver, David Hunter

    2018-01-03

    Immersion pulmonary edema is potentially a catastrophic condition; however, the pathophysiological mechanisms are ill-defined. This study assessed the individual and combined effects of exertion and negative pressure breathing on the cardiovascular system during the development of pulmonary edema in SCUBA divers. Sixteen male professional SCUBA divers performed four SCUBA dives in a freshwater pool at 1 m depth while breathing air at either a positive or negative pressure both at rest or with exercise. Echocardiography and lung ultrasound were used to assess the cardiovascular changes and lung comet score (a measure of interstitial pulmonary edema). The ultrasound lung comet score was 0 following both the dives at rest regardless of breathing pressure. Following exercise, the mean comet score rose to 4.2 with positive pressure breathing and increased to 15.1 with negative pressure breathing. The development of interstitial pulmonary edema was significantly related to inferior vena cava diameter, right atrial area, tricuspid annular plane systolic excursion, right ventricular fractional area change, and pulmonary artery pressure. Exercise combined with negative pressure breathing induced the greatest changes in these cardiovascular indices and lung comet score. A diver using negative pressure breathing while exercising is at greatest risk of developing interstitial pulmonary edema. The development of immersion pulmonary edema is closely related to hemodynamic changes in the right but not the left ventricle. Our findings have important implications for divers and understanding the mechanisms of pulmonary edema in other clinical settings.

  8. Intermittent Explosive Disorder

    Science.gov (United States)

    ... Headache Intermittent explosive disorder Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  9. Intermittent Explosive Disorder

    Directory of Open Access Journals (Sweden)

    Lut Tamam

    2011-09-01

    Full Text Available Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etiological studies displayed the role of both psychosocial factors like childhood traumas and biological factors like dysfunctional neurotransmitter systems and genetics. In differential diagnosis of the disorder, disorders involving agression as a symptom such as alcohol and drug intoxication, antisocial and borderline personality disorders, personality changes due to general medical conditions and behavioral disorder should be considered. A combination of pharmacological and psychotherapeutic approaches are suggested in the treatment of the disorder. This article briefly reviews the historical background, diagnostic criteria, epidemiology, etiology and treatment of intermittent explosive disorder.

  10. DC negative corona discharge in atmospheric pressure helium: transition from the corona to the ‘normal’ glow regime

    International Nuclear Information System (INIS)

    Hasan, Nusair; Farouk, Bakhtier; Antao, Dion S

    2014-01-01

    Direct current (dc) negative corona discharges in atmospheric pressure helium are simulated via detailed numerical modeling. Simulations are conducted to characterize the discharges in atmospheric helium for a pin plate electrode configuration. A self-consistent two-dimensional hybrid model is developed to simulate the discharges and the model predictions are validated with experimental measurements. The discharge model considered consists of momentum and energy conservation equations for a multi-component (electrons, ions, excited species and neutrals) gas mixture, conservation equations for each component of the mixture and state relations. A drift–diffusion approximation for the electron and the ion fluxes is used. A model for the external circuit driving the discharge is also considered and solved along with the discharge model. Many of the key features of a negative corona discharge, namely non-linear current–voltage characteristics, spatially flat cathode current density and glow-like discharge in the high current regime are displayed in the predictions. A transition to the ‘normal’ glow discharge from the corona discharge regime is also observed. The transition is identified from the calculated current–voltage characteristic curve and is characterized by the radial growth of the negative glow and the engulfment of the cathode wire. (paper)

  11. Stability of streambanks formed in partially saturated soils and effects of negative pore water pressures: the Sieve River (Italy)

    Science.gov (United States)

    Rinaldi, Massimo; Casagli, Nicola

    1999-01-01

    Streambanks of alluvial channels are usually composed of loose materials, which are unsaturated in ambient conditions. Unsaturated soils are subject to negative pore water pressures, which cause an apparent cohesion. The latter is the main factor in allowing the stability of near-vertical banks. Even during moderate in-bank flow events, the apparent cohesion can be strongly reduced as the material approaches full saturation; therefore, during the drawdown phase, as the confining pressure of the water in the channel disappears, a bank failure is likely to occur. Channel bed-level lowering along the Sieve River, Central Italy, has caused widespread bank instability. A geomorphological reconnaissance of forms and processes was followed by in situ tests to determine the shear strength of the banks. Interpretation of the tests and a streambank stability analysis were based on concepts of soil mechanics for unsaturated soils, in order to obtain relations between bank angle and height in limit equilibrium conditions. A stability chart was obtained with curves for different apparent cohesion values, and a stability analysis was performed taking into account the effects of flow events. In order to investigate the pore pressure effects, a series of piezo-tensiometers were installed in a streambank of the Sieve River. Data from a 1 year monitoring period show variations in pore water pressure and matric suction as a consequence of rainfall, evapotranspiration, and water stage variations. A planar failure with a tension crack occurred in the upper cohesive part of the bank during December 1996. The safety factor has been expressed as a function of the geometry of the bank and of the shear strength of the material. Safety factor variations through time are therefore shown as a function of seasonal variations in matric suction.

  12. Adapting a Vacuum Assisted Closure dressing to challenging wounds: negative pressure treatment for perineal necrotizing fasciitis with rectal prolapse in a newborn affected by acute myeloid leukaemia.

    Science.gov (United States)

    Negosanti, Luca; Aceti, Arianna; Bianchi, Tommaso; Corvaglia, Luigi; Negosanti, Francesca; Sgarzani, Rossella; Morselli, Paolo Giovanni; Cipriani, Riccardo; Negosanti, Massimino; Patrizi, Annalisa; Faldella, Giacomo

    2010-01-01

    We report the case of a newborn with acute myeloid leukaemia, who developed perineal necrotizing fasciitis due to Pseudomonas Aeruginosa, after twenty days of life. Following surgical debridement, she was effectively treated with topical negative pressure therapy (V.A.C.(R) device) with silver foam dressings, this achieved complete closure in thirteen days. Negative pressure therapy should be considered when conventional wound care fails to achieve complete wound closure, even in neonates.

  13. Effects of dressing type on 3D tissue microdeformations during negative pressure wound therapy: a computational study.

    Science.gov (United States)

    Wilkes, R; Zhao, Y; Kieswetter, K; Haridas, B

    2009-03-01

    Vacuum-assisted closure (VAC) therapy, also referred to as vacuum-assisted closure negative pressure wound therapy (VAC NPWT), delivered to various dermal wounds is believed to influence the formation of granulation tissue via the mechanism of microdeformational signals. In recent years, numerous experimental investigations have been initiated to study the cause-effect relationships between the mechanical signals and the transduction pathways that result in improved granulation response. To accurately quantify the tissue microdeformations during therapy, a new three-dimensional finite element model has been developed and is described in this paper. This model is used to study the effect of dressing type and subatmospheric pressure level on the variations in the microdeformational strain fields in a model dermal wound bed. Three-dimensional geometric models representing typical control volumes of NPWT dressings were generated using micro-CT scanning of VAC GranuFoam, a reticulated open-cell polyurethane foam (ROCF), and a gauze dressing (constructed from USP Class VII gauze). Using a nonlinear hyperfoam constitutive model for the wound bed, simulated tissue microdeformations were generated using the foam and gauze dressing models at equivalent negative pressures. The model results showed that foam produces significantly greater strain than gauze in the tissue model at all pressures and in all metrics (pobservation is consistent across all of the strain invariants assessed, i.e., epsilon(vol), epsilon(dist), the minimum and maximum principal strains, and the maximum shear strain. The distribution of the microdeformations and strain appears as a repeating mosaic beneath the foam dressing, whereas the gauze dressings appear to produce an irregular distribution of strains in the wound surface. Strain predictions from the developed computational model results agree well with those predicted from prior two-dimensional experimental and computational studies of foam

  14. Distribution assessment comparing continuous and periodic wound instillation in conjunction with negative pressure wound therapy using an agar-based model.

    Science.gov (United States)

    Rycerz, Anthony M; Slack, Paul; McNulty, Amy K

    2013-04-01

    Negative pressure wound therapy (NPWT) is a widely accepted and effective treatment for various wound types, including complex wounds. Negative pressure with instillation was initially used as a gravity-fed system whereby reticulated, open-cell foam in the wound bed was periodically exposed to cycles of soaking with instillation solution followed by NPWT. Recent publications have alluded to positive outcomes with continuous instillation, where fluid is delivered simultaneously with negative pressure. To evaluate the distribution of instillation solutions to wound beds in conjunction with negative pressure, agar-based models were developed and exposed to coloured instillation solutions to identify exposure intensity via agar staining. This model allowed comparison of continuous- versus periodic-instillation therapy with negative pressure. Continuous instillation at a rate of 30 cc/hour with negative pressure showed isolated exposure of instillation fluid to wound beds in agar wound models with and without undermining and tunnelling. In contrast, periodic instillation illustrated uniform exposure of the additive to the entire wound bed including undermined and tunnel areas, with increased staining with each instillation cycle. These findings suggest that periodic instillation facilitates more uniform exposure throughout the wound, including tunnels and undermining, to instillation solutions, thereby providing therapy consistent with the clinician-ordered treatment. © 2012 The Authors. International Wound Journal © 2012 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

  15. Effect of Reynolds Number and Periodic Unsteady Wake Flow Condition on Boundary Layer Development, Separation, and Intermittency Behavior Along the Suction Surface of a Low Pressure Turbine Blade

    Science.gov (United States)

    Schobeiri, M. T.; Ozturk, B.; Ashpis, David E.

    2007-01-01

    The paper experimentally studies the effects of periodic unsteady wake flow and different Reynolds numbers on boundary layer development, separation and re-attachment along the suction surface of a low pressure turbine blade. The experimental investigations were performed on a large scale, subsonic unsteady turbine cascade research facility at Turbomachinery Performance and Flow Research Laboratory (TPFL) of Texas A&M University. The experiments were carried out at Reynolds numbers of 110,000 and 150,000 (based on suction surface length and exit velocity). One steady and two different unsteady inlet flow conditions with the corresponding passing frequencies, wake velocities, and turbulence intensities were investigated. The reduced frequencies chosen cover the operating range of LP turbines. In addition to the unsteady boundary layer measurements, surface pressure measurements were performed. The inception, onset, and the extent of the separation bubble information collected from the pressure measurements were compared with the hot wire measurements. The results presented in ensemble-averaged, and the contour plot forms help to understand the physics of the separation phenomenon under periodic unsteady wake flow and different Reynolds number. It was found that the suction surface displayed a strong separation bubble for these three different reduced frequencies. For each condition, the locations defining the separation bubble were determined carefully analyzing and examining the pressure and mean velocity profile data. The location of the boundary layer separation was dependent of the Reynolds number. It is observed that starting point of the separation bubble and the re-attachment point move further downstream by increasing Reynolds number from 110,000 to 150,000. Also, the size of the separation bubble is smaller when compared to that for Re=110,000.

  16. Experience with the vacuum assisted closure negative pressure technique in the treatment of non-healing diabetic and dysvascular wounds.

    Science.gov (United States)

    Clare, Michael P; Fitzgibbons, Timothy C; McMullen, Scott T; Stice, R Colleen; Hayes, Dennis F; Henkel, Loree

    2002-10-01

    The purpose of this study is to report our experience with the Vacuum Assisted Closure (VAC) negative pressure technique in patients with non-healing wounds of the foot, ankle, and lower limb. We retrospectively reviewed 17 patients with non-healing wounds of the lower extremity who underwent treatment using the Vacuum Assisted Closure (VAC) device. Thirteen of 17 (76%) had diabetes mellitus, nine of whom were insulin-dependent, and 10 of whom had associated peripheral neuropathy. Eight of 17 (47%) had severe peripheral vascular disease. All had failed previous management with serial wound debridements and dressing changes; 15 of 17 (88%) had previously completed at least one course of oral antibiotics. Thirteen of 17 (76%) had previously undergone operative irrigation and debridement of the wounds; six of 17 (35%) had previously undergone revascularization procedures of the involved extremity. Five of 17 (29%) had wounds necessitating an amputation procedure prior to the present treatment; seven of 17 (41%) had failed treatment with local growth factors prior to the present treatment. Average length of treatment with the VAC device was 8.2 weeks. Fourteen of 17 (82%) wounds successfully healed; four underwent split-thickness skin grafting for wound closure; four were briefly treated with local growth factors; six were treated with only dressing changes following VAC treatment. Three of 17 (18%) wounds failed VAC treatment; all three patients had diabetes and had wounds located in the midfoot or forefoot; two of three had severe peripheral vascular disease. Our results indicate that the Vacuum Assisted Closure negative pressure technique is emerging as an acceptable option for wound care of the lower extremity. Not all patients are candidates for such treatment; those patients with severe peripheral vascular disease or smaller forefoot wounds may be best treated by other modalities. Larger wounds seem to be better suited for skin grafting or two-stage primary

  17. High bacterial load in negative pressure wound therapy (NPWT) foams used in the treatment of chronic wounds.

    Science.gov (United States)

    Yusuf, Erlangga; Jordan, Xavier; Clauss, Martin; Borens, Olivier; Mäder, Mark; Trampuz, Andrej

    2013-01-01

    No earlier study has investigated the microbiology of negative pressure wound therapy (NPWT) foam using a standardized manner. The purpose of this study is to investigate the bacterial load and microbiological dynamics in NPWT foam removed from chronic wounds (>3 months). To determine the bacterial load, a standardized size of the removed NPWT foam was sonicated. The resulting sonication fluid was cultured, and the colony-forming units (CFU) of each species were enumerated. Sixty-eight foams from 17 patients (mean age 63 years, 71% males) were investigated. In 65 (97%) foams, ≥ 1 and in 37 (54%) ≥ 2 bacterial types were found. The bacterial load remained high during NPWT treatment, ranging from 10(4) to 10(6) CFU/ml. In three patients (27%), additional type of bacteria was found in subsequent foam cultures. The mean bacterial count ± standard deviation was higher in polyvinyl alcohol foam (6.1 ± 0.5 CFU/ml) than in polyurethane (5.5 ± 0.8 CFU/ml) (p = 0.02). The mean of log of sum of CFU/ml in foam from 125 mmHg (5.5 ± 0.8) was lower than in foam from 100 mmHg pressure (5.9 ± 0.5) (p = 0.01). Concluding, bacterial load remains high in NPWT foam, and routine changing does not reduce the load. © 2013 by the Wound Healing Society.

  18. The Bagautdinov dressing method: negative pressure wound therapy in a patient with an allergy to acrylate adhesive.

    Science.gov (United States)

    Daar, David A; Wirth, Garrett A; Evans, Gregory Rd; Carmean, Melissa; Gordon, Ian L

    2017-02-01

    Current embodiments of negative pressure wound therapy (NPWT) create a hermetically sealed chamber at the surface of the body using polyurethane foam connected to a vacuum pump, which is then covered by a flexible adhesive drape. Commercially available NPWT systems routinely use flexible polyethylene films that have a sticky side, coated with the same acrylate adhesives used in other medical devices such as ECG leads and grounding pads. Severe reactions to the acrylate adhesives in these other devices, although uncommon, have been reported. We describe the case of a 63-year-old woman with an intractable leg ulcer resulting from external-beam radiotherapy (XRT). Treatment with a standard commercial NPWT system induced severe inflammation of the skin in direct contact with drape adhesive. We successfully administered prolonged, outpatient NPWT to the patient using an alternative method (first described by Bagautdinov in 1986), using plain polyethylene film and petrolatum. The necessary hermetic seal is achieved by smearing the skin with petrolatum before applying the polyethylene film and activating the vacuum pump. The Bagautdinov method is a practical solution to the problem of adapting NPWT to patients with contact sensitivity or skin tears related to the adhesive compounds in the flexible drapes. Its use of a circumferential elastic wrap to maintain constant pressure on the seal probably limits the Bagautdinov technique to the extremities. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  19. The effect of blood volume loss on cardiovascular response to lower body negative pressure using a mathematical model

    Science.gov (United States)

    Karam, E. H.; Srinivasan, R. S.; Charles, J. B.; Fortney, S. M.

    1994-01-01

    Different mathematical models of varying complexity have been proposed in recent years to study the cardiovascular (CV) system. However, only a few of them specifically address the response to lower body negative pressure (LBNP), a stress that can be applied in weightlessness to predict changes in orthostatic tolerance. Also, the simulated results produced by these models agree only partially with experimental observations. In contrast, the model proposed by Melchior et al., and modified by Karam et al. is a simple representation of the CV system capable of accurately reproducing observed LBNP responses up to presyncopal levels. There are significant changes in LBNP response due to a loss of blood volume and other alterations that occur in weightlessness and related one-g conditions such as bedrest. A few days of bedrest can cause up to 15% blood volume loss (BVL), with consequent decreases in both stroke volume and cardiac output, and increases in heart rate, mean arterial pressure, and total peripheral resistance. These changes are more pronounced at higher levels of LBNP. This paper presents the results of a simulation study using our CV model to examine the effect of BVL on LBNP response.

  20. RESTING SYMPATHETIC BAROREFLEX SENSITIVITY IN SUBJECTS WITH LOW AND HIGH TOLERANCE TO CENTRAL HYPOVOLEMIA INDUCED BY LOWER BODY NEGATIVE PRESSURE

    Directory of Open Access Journals (Sweden)

    Carmen eHinojosa-Laborde

    2014-06-01

    Full Text Available Central hypovolemia elicited by orthostasis or hemorrhage triggers sympathetically-mediated baroreflex responses to maintain organ perfusion; these reflexes are less sensitive in patients with orthostatic intolerance, and during conditions of severe blood loss, may result in cardiovascular collapse (decompensatory or circulatory shock. The ability to tolerate central hypovolemia is variable and physiological factors contributing to tolerance are emerging. We tested the hypothesis that resting muscle sympathetic nerve activity (MSNA and sympathetic baroreflex sensitivity (BRS are attenuated in male and female subjects who have low tolerance (LT to central hypovolemia induced by lower body negative pressure (LBNP. MSNA and diastolic arterial pressure (DAP were recorded in 47 human subjects who subsequently underwent LBNP to tolerance (onset of presyncopal symptoms. LT subjects experienced presyncopal symptoms prior to completing LBNP of -60 mm Hg, and subjects with high tolerance (HT experienced presyncopal symptoms after completing LBNP after -60 mmHg. Contrary to our hypothesis, resting MSNA burst incidence was not different between LT and HT subjects, and was not related to time to presyncope. BRS was assessed as the slope of the relationship between spontaneous fluctuations in DAP and MSNA during 5 min of supine rest. MSNA burst incidence/DAP correlations were greater than or equal to 0.5 in 37 subjects (LT: n= 9; HT: n=28, and BRS was not different between LT and HT (-1.8 ± 0.3 vs. -2.2 ± 0.2 bursts•(100 beats-1•mmHg-1, p=0.29. We conclude that tolerance to central hypovolemia is not related to either resting MSNA or sympathetic BRS.

  1. In-flight Assessment of Lower Body Negative Pressure as a Countermeasure for Post-flight Orthostatic Intolerance

    Science.gov (United States)

    Charles, J. B.; Stenger, M. B.; Phillips, T. R.; Arzeno, N. M.; Lee, S. M. C.

    2009-01-01

    Introduction. We investigated the efficacy of combining fluid loading with sustained lower body negative pressure (LBNP) to reverse orthostatic intolerance associated with weightlessness during and immediately after Space Shuttle missions. Methods. Shuttle astronauts (n=13) underwent 4 hours of LBNP at -30 mm(Hg) and ingested water and salt ( soak treatment) during flight in two complementary studies. In the first study (n=8), pre-flight heart rate (HR) and blood pressure (BP) responses to an LBNP ramp (5-min stages of -10 mm(Hg) steps to -50 mm(Hg) were compared to responses in-flight one and two days after LBNP soak treatment. In the second study (n=5), the soak was performed 24 hr before landing, and post-flight stand test results of soak subjects were compared with those of an untreated cohort (n=7). In both studies, the soak was scheduled late in the mission and was preceded by LBNP ramp tests at approximately 3-day intervals to document the in-flight loss of orthostatic tolerance. Results. Increased HR and decreased BP responses to LBNP were evident early in-flight. In-flight, one day after LBNP soak, HR and BP responses to LBNP were not different from pre-flight, but the effect was absent the second day after treatment. Post-flight there were no between-group differences in HR and BP responses to standing, but all 5 treatment subjects completed the 5-minute stand test whereas 2 of 7 untreated cohort subjects did not. Discussion. Exaggerated HR and BP responses to LBNP were evident within the first few days of space flight, extending results from Skylab. The combined LBNP and fluid ingestion countermeasure restored in-flight LBNP HR and BP responses to pre-flight levels and provided protection of post-landing orthostatic function. Unfortunately, any benefits of the combined countermeasure were offset by the complexity of its implementation, making it inappropriate for routine application during Shuttle flights.

  2. Role of different negative pressure values in the process of infected wounds treated by vacuum-assisted closure: an experimental study.

    Science.gov (United States)

    Zhou, Min; Yu, Aixi; Wu, Gang; Xia, Chengyan; Hu, Xiang; Qi, Baiwen

    2013-10-01

    Vacuum-assisted closure (VAC) device is widely used to treat infected wounds in clinical work. Although the effect of VAC with different negative pressure values is well established, whether different negative pressures could result in varying modulation of wound relative cytokines was not clear. We hypothesise that instead of the highest negative pressure value the suitable value for VAC is the one which is the most effective on regulating wound relative cytokines. Infected wounds created on pigs' back were used to investigate the effects of varying negative pressure values of VAC devices. Wounds were treated with VAC of different negative pressure values or moist gauze, which was set as control. The VAC foam, semiocclusive dresses and moist gauze were changed on days 3, 5, 7 and 9 after wounds were created. When changing dressings, tissues from wounds were harvested for bacteria count and histology examination including Masson's trichrome stain and immunohistochemistry for microvessels. Western blot was carried out to test the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). Results showed that on days 3 and 5 the number of bacteria in wounds treated by VAC with 75, 150, 225 and 300 mmHg was significantly decreased compared with that in wounds treated by gauze and 0 mmHg pressure value. However, there was no difference in wounds treated with negative pressure values of 75 , 150, 225 and 300 mmHg at any time spot. Immunohistochemistry showed that more microvessels were generated in wounds treated by VAC using 75 and 150 mmHg negative pressure comparing with that using 225 and 300 mmHg on days 3 and 5. However this difference vanished on days 7 and 9. Morphological evaluation by Masson's trichrome staining showed increased collagen deposition in VAC of 75 and 150 mmHg compared with that in VAC of 225 and 300 mmHg. Western blot showed that the expression of VEGF and bFGF significantly increased when the wounds

  3. Fate in intermittent claudication

    DEFF Research Database (Denmark)

    Jelnes, Rolf; Gaardsting, O; Hougaard Jensen, K

    1986-01-01

    The fate of 257 consecutive patients (100 women) aged 36-85 years (mean 65) first seen with intermittent claudication in 1977 was analysed after a mean of 6.5 (SD 0.5) years. When first seen none of the patients complained of rest pain or had ulcers or gangrenous lesions on the feet. At follow up...

  4. Homemade-device-induced negative pressure promotes wound healing more efficiently than VSD-induced positive pressure by regulating inflammation, proliferation and remodeling.

    Science.gov (United States)

    Liu, Jinyan; Hu, Feng; Tang, Jintian; Tang, Shijie; Xia, Kun; Wu, Song; Yin, Chaoqi; Wang, Shaohua; He, Quanyong; Xie, Huiqing; Zhou, Jianda

    2017-04-01

    Vacuum sealing drainage (VSD) is an effective technique used to promote wound healing. However, recent studies have shown that it exerts positive pressure (PP) rather than negative pressure (NP) on skin. In this study, we created a homemade device that could maintain NP on the wound, and compared the therapeutic effects of VSD-induced PP to those of our homemade device which induced NP on wound healing. The NP induced by our device required less time for wound healing and decreased the wound area more efficiently than the PP induced by VSD. NP and PP both promoted the inflammatory response by upregulating neutrophil infiltration and interleukin (IL)‑1β expression, and downregulating IL‑10 expression. Higher levels of epidermal growth factor (EGF), transforming growth factor (TGF)‑β and platelet-derived growth factor (PDGF), and lower levels of basic fibroblast growth factor (bFGF) were observed in the wound tissue treated with NP compared to the wound tissue exposed to PP. Proliferation in the wound tissue exposed to NP on day 10 was significantly higher than that in wound tissue exposed to PP. NP generated more fibroblasts, keratinized stratified epithelium, and less epithelia with stemness than PP. The levels of ccollagen Ⅰ and Ⅲ were both decreased in both the NP and PP groups. NP induced a statistically significant increase in the expression of fibronectin (FN) on days 3 and 10 compared to PP. Furthermore, the level of matrix metalloproteinase (MMP)‑13 increased in the NP group, but decreased in the PP group on day 3. NP also induced a decrease in the levels of tissue inhibitor of metalloproteinase (TIMP)‑1 and TIMP‑2 during the early stages of wound healing, which was significantly different from the increasing effect of PP on TIMP‑1 and TIMP‑2 levels at the corresponding time points. On the whole, our data indicate that our homemade device which induced NP, was more efficient than VSD‑induced PP on wound healing by

  5. Simultaneous irrigation and negative pressure wound therapy enhances wound healing and reduces wound bioburden in a porcine model.

    Science.gov (United States)

    Davis, Kathryn; Bills, Jessica; Barker, Jenny; Kim, Paul; Lavery, Lawrence

    2013-01-01

    Infected foot wounds are one of the most common reasons for hospitalization and amputation among persons with diabetes. The objective of the study was to investigate a new wound therapy system that employs negative pressure wound therapy (NPWT) with simultaneous irrigation therapy. For this study, we used a porcine model with full-thickness excisional wounds, inoculated with Pseudomonas aeruginosa. Wounds were treated for 21 days of therapy with either NPWT, NPWT with simultaneous irrigation therapy using normal saline or polyhexanide biguanide (PHMB) at low or high flow rates, or control. Data show that NPWT with either irrigation condition improved wound healing rates over control-treated wounds, yet did not differ from NPWT alone. NPWT improved bioburden over control-treated wounds. NPWT with simultaneous irrigation further reduced bioburden over control and NPWT-treated wounds; however, flow rate did not affect these outcomes. Together, these data show that NPWT with simultaneous irrigation therapy with either normal saline or PHMB has a positive effect on bioburden in a porcine model, which may translate clinically to improved wound healing outcomes. © 2013 by the Wound Healing Society.

  6. Platelet-rich plasma, bilayered acellular matrix grafting and negative pressure wound therapy in diabetic foot infection.

    Science.gov (United States)

    Deng, W; Boey, J; Chen, B; Byun, S; Lew, E; Liang, Z; Armstrong, D G

    2016-07-02

    Management and treatment of acute severe diabetic foot disease in patients with suboptimal glycaemic control is a critical issue in wound repair. This paper discusses the clinical efficacy of an aggressive surgical intervention combined with targeted use of regenerative medical therapies in limb preservation. Negative pressure wound therapy (NPWT), platelet-rich plasma (PRP), bilayered acellular matrix grafting and split-thickness skin grafting were combined to treat a patient with diabetes, foot necrotising fasciitis and gaseous gangrene. The wound was completely healed. The clinical outcome revealed that a multi-intervention strategy could be effective for large necrotising fasciitis wounds. Early clinical observation, suggests aggresive surgical intervention preserving intact tissue and targeted use of new regenerative technologies can lead to preservation of a limb. The authors have received no financial support for the material presented in this study outside of the scope of standard patient care reimbursement. This work was supported by the National Natural Science Foundation of China (NO. 81500596) awarded to Dr Wuquan Deng.

  7. Measurement of vancomycin hydrochloride concentration in the exudate from wounds receiving negative pressure wound therapy: a pilot study.

    Science.gov (United States)

    Ida, Yukiko; Matsumura, Hajime; Onishi, Masami; Ono, Sayaka; Imai, Ryutaro; Watanabe, Katsueki

    2016-04-01

    It has been reported that negative pressure wound therapy (NPWT) is effective in the treatment of contaminated wounds. We hypothesised that systemically administered antibiotics migrate to wound site effectively by NPWT, which provides the antibacterial effect. We measured and compared the concentrations of vancomycin in the exudate and blood serum. Eight patients with skin ulcers or skin defect wounds who were treated with NPWT and were administered an intravenous drip of vancomycin were enrolled in this study. The wound surfaces were muscle, muscle fascia or adipose tissue. We administered vancomycin intravenously to NPWT patients (1-3 g/day). The exudate was obtained using 500 ml V.A.C. ATS canisters without gel. Three days later, the concentrations of vancomycin were measured. The mean concentration of vancomycin in the exudate from NPWT was 67% of the serum vancomycin concentration. We found that concentrations of vancomycin in NPWT exudates are higher than the previously reported concentrations in soft tissue without NPWT. The proactive use of NPWT might be considered in cases of suspected wound contamination when a systemic antibiotic is administered. © 2014 The Authors. International Wound Journal © 2014 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  8. Wound management with negative pressure wound therapy in postoperative infection after open reconstruction of chronic Achilles tendon rupture.

    Science.gov (United States)

    Saku, Isaku; Kanda, Shotaro; Saito, Toshihiro; Fukushima, Takashi; Akiyama, Toru

    2017-01-01

    Deep infection after reconstruction of chronic Achilles tendon rupture is a major and intractable complication. We report a case of late deep infection following a surgery for chronic Achilles tendon rupture, and its simple and successful treatment with negative pressure wound therapy (NPWT). Six months following the reconstruction of chronic Achilles tendon rupture, a deep infection developed and reconstructed part of the tendon ruptured again. After appropriate debridement. There is no definitive treatment strategy for postoperative infection following open Achilles tendon repair. NPWT was applied to the wound, to promote wound healing and healthy granulation. In our case, NPWT promoted the wound healing and the infected Achilles tendon with tendon loss formed a healthy bridge with granulation tissue spontaneously. The patient resumed her normal activities of daily living, without requiring tendon transfer surgery. NPWT seems to be a simple and successful candidate for this situation. NPWT seems to be effective for the treatment of postoperative infection following Achilles tendon repair, even in cases of tendon loss. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Use of Bacteria- and Fungus-Binding Mesh in Negative Pressure Wound Therapy Provides Significant Granulation Tissue Without Tissue Ingrowth

    Science.gov (United States)

    Malmsjö, Malin; Lindstedt, Sandra; Ingemansson, Richard; Gustafsson, Lotta

    2014-01-01

    Objective: Bacteria- and fungus-binding mesh traps and inactivates bacteria and fungus, which makes it interesting, alternative, and wound filler for negative pressure wound therapy (NPWT). The aim of this study was to compare pathogen-binding mesh, black foam, and gauze in NPWT with regard to granulation tissue formation and ingrowth of wound bed tissue in the wound filler. Methods: Wounds on the backs of 8 pigs underwent 72 hours of NPWT using pathogen-binding mesh, foam, or gauze. Microdeformation of the wound bed and granulation tissue formation and the force required to remove the wound fillers was studied. Results: Pathogen-binding mesh produced more granulation tissue, leukocyte infiltration, and tissue disorganization in the wound bed than gauze, but less than foam. All 3 wound fillers caused microdeformation of the wound bed surface. Little force was required to remove pathogen-binding mesh and gauze, while considerable force was needed to remove foam. This is the result of tissue growth into the foam, but not into pathogen-binding mesh or gauze, as shown by examination of biopsy sections from the wound bed. Conclusions: This study shows that using pathogen-binding mesh as a wound filler for NPWT leads to a significant amount of granulation tissue in the wound bed, more than that with gauze, but eliminates the problems of ingrowth of the wound bed into the wound filler. Pathogen-binding mesh is thus an interesting wound filler in NPWT. PMID:24501617

  10. Negative Pressure Wound Therapy on Surgical Site Infections in Women Undergoing Elective Caesarean Sections: A Pilot RCT.

    Science.gov (United States)

    Chaboyer, Wendy; Anderson, Vinah; Webster, Joan; Sneddon, Anne; Thalib, Lukman; Gillespie, Brigid M

    2014-09-30

    Obese women undergoing caesarean section (CS) are at increased risk of surgical site infection (SSI). Negative Pressure Wound Therapy (NPWT) is growing in use as a prophylactic approach to prevent wound complications such as SSI, yet there is little evidence of its benefits. This pilot randomized controlled trial (RCT) assessed the effect of NPWT on SSI and other wound complications in obese women undergoing elective caesarean sections (CS) and also the feasibility of conducting a definitive trial. Ninety-two obese women undergoing elective CS were randomized in theatre via a central web based system using a parallel 1:1 process to two groups i.e., 46 women received the intervention (NPWT PICO™ dressing) and 46 women received standard care (Comfeel Plus(®) dressing). All women received the intended dressing following wound closure. The relative risk of SSI in the intervention group was 0.81 (95% CI 0.38-1.68); for the number of complications excluding SSI it was 0.98 (95% CI 0.34-2.79). A sample size of 784 (392 per group) would be required to find a statistically significant difference in SSI between the two groups with 90% power. These results demonstrate that a larger definitive trial is feasible and that careful planning and site selection is critical to the success of the overall study.

  11. Negative Pressure Wound Therapy on Surgical Site Infections in Women Undergoing Elective Caesarean Sections: A Pilot RCT

    Directory of Open Access Journals (Sweden)

    Wendy Chaboyer

    2014-09-01

    Full Text Available Obese women undergoing caesarean section (CS are at increased risk of surgical site infection (SSI. Negative Pressure Wound Therapy (NPWT is growing in use as a prophylactic approach to prevent wound complications such as SSI, yet there is little evidence of its benefits. This pilot randomized controlled trial (RCT assessed the effect of NPWT on SSI and other wound complications in obese women undergoing elective caesarean sections (CS and also the feasibility of conducting a definitive trial. Ninety-two obese women undergoing elective CS were randomized in theatre via a central web based system using a parallel 1:1 process to two groups i.e., 46 women received the intervention (NPWT PICO™ dressing and 46 women received standard care (Comfeel Plus® dressing. All women received the intended dressing following wound closure. The relative risk of SSI in the intervention group was 0.81 (95% CI 0.38–1.68; for the number of complications excluding SSI it was 0.98 (95% CI 0.34–2.79. A sample size of 784 (392 per group would be required to find a statistically significant difference in SSI between the two groups with 90% power. These results demonstrate that a larger definitive trial is feasible and that careful planning and site selection is critical to the success of the overall study.

  12. The Haiti earthquake: the provision of wound care for mass casualties utilizing negative-pressure wound therapy.

    Science.gov (United States)

    Gabriel, Allen; Gialich, Shelby; Kirk, Julie; Edwards, Sheriden; Beck, Brooke; Sorocéanu, Alexandra; Nelson, Scott; Gabriel, Cassie; Gupta, Subhas

    2011-10-01

    Many months after the devastating earthquake in January 2010, wounds remain a major disease burden in Haiti. Since January 2010, through the efforts of corporations, nonprofit charitable organizations, and medical professionals, advanced wound care techniques, including negative-pressure wound therapy (NPWT), have been introduced into the wound care regimens of various hospitals in Haiti. In June 2010, the authors completed their second volunteer trip at a Haitian hospital specializing in orthopedic wounds. The medical team was composed of a plastic surgeon, orthopedic surgeon, anesthesiologist, medical assistant, scrub technician, and registered nurse (specializing in plastic surgery and orthopedics). The authors' team supplied NPWT devices, reticulated open-cell foam dressings, and canisters donated by Kinetic Concepts, Inc, San Antonio, Texas, for use at the hospital. This report describes the medical challenges in postearthquake Haiti (including limb salvage and infection), benefits of adjunctive use of NPWT/reticulated open-cell foam, and current wound care status in a Haitian orthopedic hospital. The future role of NPWT in Haiti and during mass catastrophe in a least-developed country is also discussed.

  13. Negative Pressure Wound Therapy Applied Before and After Split-Thickness Skin Graft Helps Healing of Fournier Gangrene

    Science.gov (United States)

    Ye, Junna; Xie, Ting; Wu, Minjie; Ni, Pengwen; Lu, Shuliang

    2015-01-01

    Abstract Fournier gangrene is a rare but highly infectious disease characterized by fulminant necrotizing fasciitis involving the genital and perineal regions. Negative pressure wound therapy (NPWT; KCI USA Inc, San Antonio, TX) is a widely adopted technique in many clinical settings. Nevertheless, its application and effect in the treatment of Fournier gangrene are unclear. A 47-year-old male patient was admitted with an anal abscess followed by a spread of the infection to the scrotum, which was caused by Pseudomonas aeruginosa. NPWT was applied on the surface of the scrotal area and continued for 10 days. A split-thickness skin graft from the scalp was then grafted to the wound, after which, NPWT utilizing gauze sealed with an occlusive dressing and connected to a wall suction was employed for 7 days to secure the skin graft. At discharge, the percentage of the grafted skin alive on the scrotum was 98%. The wound beside the anus had decreased to 4 × 0.5 cm with a depth of 1 cm. Follow-up at the clinic 1 month later showed that both wounds had healed. The patient did not complain of any pain or bleeding, and was satisfied with the outcome. NPWT before and after split-thickness skin grafts is safe, well tolerated, and efficacious in the treatment of Fournier gangrene. PMID:25654376

  14. Anomalous thermal expansion, negative linear compressibility, and high-pressure phase transition in ZnAu2(CN) 4 : Neutron inelastic scattering and lattice dynamics studies

    Science.gov (United States)

    Gupta, Mayanak K.; Singh, Baltej; Mittal, Ranjan; Zbiri, Mohamed; Cairns, Andrew B.; Goodwin, Andrew L.; Schober, Helmut; Chaplot, Samrath L.

    2017-12-01

    We present temperature-dependent inelastic-neutron-scattering measurements, accompanied by ab initio calculations of the phonon spectra and elastic properties as a function of pressure to quantitatively explain an unusual combination of negative thermal expansion and negative linear compressibility behavior of ZnAu2(CN) 4 . The mechanism of the negative thermal expansion is identified in terms of specific anharmonic phonon modes that involve bending of the -Zn-NC-Au-CN-Zn- linkage. The soft phonon at the L point at the Brillouin zone boundary quantitatively relates to the high-pressure phase transition at about 2 GPa. The ambient pressure structure is also found to be close to an elastic instability that leads to a weakly first-order transition.

  15. The use of a negative pressure wound management system in perineal wound closure after extralevator abdominoperineal excision (ELAPE) for low rectal cancer.

    Science.gov (United States)

    Sumrien, H; Newman, P; Burt, C; McCarthy, K; Dixon, A; Pullyblank, A; Lyons, A

    2016-09-01

    Perineal wound healing is a significant challenge after extralevator abdominoperineal excision (ELAPE) due to a high rate of wound breakdown. Negative pressure therapy has proven benefits in open wounds, and recently a negative pressure system has been developed for use on closed wounds at high risk of breakdown, such as apronectomy and hysterectomy. The aim of the present study was to determine whether negative pressure therapy applied to closed perineal wounds after ELAPE improved wound healing and compare outcomes to the published literature and outcomes from a historical cohort of patients who had undergone 'standard' abdominoperineal resection (APR) and primary closure of the perineal wounds. Prospective data on consecutive patients having ELAPE in the period from November 2012 to April 2015 were collected. The pelvic floor defect was reconstructed with biologic mesh. The adipose tissue layer was closed with vicryl sutures, a suction drain was left in the deep layer, the subcuticular layer and skin were closed, and the negative pressure system was applied. Any wound breakdown within the first 30 days postoperatively was recorded. Of the 32 consecutive ELAPE patients whose perineal wounds were closed within 30 days with the use of the negative pressure system, there was 1 patient with major perineal wound breakdown and 2 patients with a 1 cm superficial wound defect, which needed no further treatment. In the remaining 29 (90 %) patients, the perineal wounds healed fully without complications. Twenty-five patients underwent standard APR in 2010-2011 with primary closure of their perineal wounds. Ten out of 25(40 %) of patients who had undergone standard APR and primary closure of perineal wounds had major wound complications (p = 0.01). Our results suggest that after ELAPE the application of a negative pressure system to the perineal wound closed with biologic mesh may reduce perineal wound complications and may reduce the need for major perineal

  16. How bacterial cell division might cheat turgor pressure - a unified mechanism of septal division in Gram-positive and Gram-negative bacteria.

    Science.gov (United States)

    Erickson, Harold P

    2017-08-01

    An important question for bacterial cell division is how the invaginating septum can overcome the turgor force generated by the high osmolarity of the cytoplasm. I suggest that it may not need to. Several studies in Gram-negative bacteria have shown that the periplasm is isoosmolar with the cytoplasm. Indirect evidence suggests that this is also true for Gram-positive bacteria. In this case the invagination of the septum takes place within the uniformly high osmotic pressure environment, and does not have to fight turgor pressure. A related question is how the V-shaped constriction of Gram-negative bacteria relates to the plate-like septum of Gram-positive bacteria. I collected evidence that Gram-negative bacteria have a latent capability of forming plate-like septa, and present a model in which septal division is the basic mechanism in both Gram-positive and Gram-negative bacteria. © 2017 WILEY Periodicals, Inc.

  17. Rapid and variable-volume sample loading in sieving electrophoresis microchips using negative pressure combined with electrokinetic force.

    Science.gov (United States)

    Qi, Li-Ya; Yin, Xue-Feng; Zhang, Lei; Wang, Min

    2008-07-01

    A rapid and variable-volume sample loading scheme for chip-based sieving electrophoresis was developed by negative pressure combined with electrokinetic force. This was achieved by using a low-cost microvacuum pump and a single potential supply at a constant voltage. Both 12% linear polyacrylamide (LPA) with a high viscosity of 15000 cP and 2% hydroxyethylcellulose (HEC) with a low viscosity of 102 cP were chosen as the sieving materials to study the behavior and the versatility of the proposed method. To reduce the hydrodynamic resistance in the sampling channel, sieving material was only filled in the separation channel between the buffer waste reservoir (BW) to the edge of the crossed intersection. By applying a subambient pressure to the headspace of sample waste reservoir (SW), sample and buffer solution were drawn immediately from sample reservoir (S) and buffer reservoir (B) across the intersection to SW. At the same time, the charged sample in the sample flow was driven across the interface between the sample flow and the sieving matrix into the sieving material filled separation channel by the applied electric field. The injected sample plug length is in proportion with the loading time. Once the vacuum in SW reservoir was released to activate electrophoretic separation, flows from S and B to SW were immediately terminated by the back flow induced by the difference of the liquid levels in the reservoirs to prevent sample leakage during the separation stage. The sample consumption was about 1.7 x 10(2) nL at a loading time of 1 s for each cycle. Only 0.024 s was required to transport bias-free analyte to the injection point. It is easy to freely choose the sample plug volume in this method by simply changing the loading time and to inject high quality sample plug with non-distorted shape into the separation channel. The system has been proved to possess an exciting potential for improving throughput, repeatability, sensitivity and separation performance of

  18. Negative pressure wound therapy via vacuum-assisted closure following partial foot amputation: what is the role of wound chronicity?

    Science.gov (United States)

    Armstrong, David G; Lavery, Lawrence A; Boulton, Andrew J M

    2007-03-01

    Randomised clinical trials (RCTs) to evaluate diabetic foot wound therapies have systematically eliminated large acute wounds from evaluation, focusing only on smaller chronic wounds. The purpose of this study was to evaluate the proportion and rate of wound healing in acute and chronic wounds after partial foot amputation in individuals with diabetes treated with negative pressure wound therapy (NPWT) delivered by the vacuum-assisted closure (VAC) device or with standard wound therapy (SWT). This study constitutes a secondary analysis of patients enrolled in a 16-week RCT of NPWT: 162 open foot amputation wounds (mean wound size = 20.7 cm(2)) were included. Acute wounds were defined as the wounds less than 30 days after amputation, whereas chronic wounds as the wounds greater than 30 days. Inclusion criteria consisted of individuals older than 18 years, presence of a diabetic foot amputation wound up to the transmetatarsal level and adequate perfusion. Wound size and healing were confirmed by independent, blinded wound evaluators. Analyses were done on an intent-to-treat basis. There was a significantly higher proportion of acute wounds (SWT = 59; NPWT = 63) than chronic wounds (SWT = 26; NPWT = 14), evaluated in this clinical trial (P = 0.001). There was no significant difference in the proportion of acute and chronic wounds achieving complete wound closure in either treatment group. Despite this finding, the Kaplan-Meier curves demonstrated statistically significantly faster healing in the NPWT group in both acute (P = 0.030) and chronic wounds (P = 0.033). Among the patients treated with NPWT via the VAC, there was not a significant difference in healing as a function of chronicity. In both the acute and the chronic wound groups, results for patients treated with NPWT were superior to those for the patients treated with SWT. These results appear to indicate that wound duration should not deter the clinician from using this modality to treat complex wounds.

  19. Changes in body core temperatures and heat balance after an abrupt release of lower body negative pressure in humans

    Science.gov (United States)

    Tanabe, Minoru; Shido, Osamu

    1994-03-01

    Changes in body core temperature ( T cor) and heat balance after an abrupt release of lower body negative pressure (LBNP) were investigated in 5 volunteers under the following conditions: (1) an ambient temperature ( T a) of 20 °C or (2) 35 °C, and (3) T a of 25 °C with a leg skin temperature of 30°C or (4) 35°C. The leg skin temperature was controlled with water perfusion devices wound around the legs. Rectal ( T re), tympanic ( T ty) and esophageal ( T es) temperatures, skin temperatures (7 sites) and oxygen consumption were measured. The intensity of LBNP was adjusted so that the amount of blood pooled in the legs was the same under all conditions. When a thermal balance was attained during LBNP, application of LBNP was suddenly halted. The skin temperatures increased significantly after the release of LBNP under all conditions, while oxygen consumption hardly changed. The release of LBNP caused significant falls in T cor s under conditions (1) and (3), but lowered T cor s very slightly under conditions (2) and (4). The changes in T es were always more rapid and greater than those of T ty and T re. The falls in T ty and T re appeared to be explained by changes in heat balance, whereas the sharp drop of T es could not be explained especially during the first 8 min after the release of LBNP. The results suggest that a fall in T cor after a release of LBNP is attributed to an increase in heat loss due to reflexive skin vasodilation and is dependent on the temperature of venous blood returning from the lower body. It is presumed that T es may not be an appropriate indicator for T cor when venous return changes rapidly.

  20. Negative pressure wound therapy in the management of late deep infections after open reconstruction of achilles tendon rupture.

    Science.gov (United States)

    Mosser, Philipp; Kelm, Jens; Anagnostakos, Konstantinos

    2015-01-01

    Infection is a major complication after open reconstruction of Achilles tendon ruptures. We report on the use of vacuum-assisted closure (VAC) therapy in the treatment of late deep infections after open Achilles tendon reconstruction. Six patients (5 males [83.33%], 1 female [16.67%]; mean age, 52.8 [range 37 to 66] years) were been treated using an identical protocol. Surgical management consisted of debridement, lavage, and necrectomy of infected tendon parts. The VAC therapy was used for local wound preconditioning and infection management. A continuous negative pressure of 125 mm Hg was applied on each wound. For final wound closure, a split-thickness skin graft was performed. The skin graft healing process was also supported by VAC therapy during the first 5 days. The VAC dressings were changed a mean average of 3 (range 1 to 4) times until split-thickness skin grafting could be performed. The mean total duration of the VAC therapy was 13.6 ± 5.9 days. The mean hospital stay was 31.2 ± 15.9 days. No complications with regard to bleeding, seroma, or hematoma formation beneath the skin graft were observed. At a mean follow-up duration of 29.9 (range 4 to 65) months, no re-infection or infection persistence was observed. The VAC device seems to be a valuable tool in the treatment of infected tendons. The generalization of these conclusions should await the results of future studies with larger patient series. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  1. Negative pressure wound therapy in the management of mine blast injuries of lower limbs: Lessons learnt at a tertiary care center.

    Science.gov (United States)

    Maurya, Sanjay; Srinath, N; Bhandari, P S

    2017-10-01

    Mine blast injuries of foot are devastating injuries that result in composite tissue loss or amputations. Negative pressure wound therapy has helped in the management of such combat-related wounds. The aim of this study was to report experiences gained in managing such injuries at a tertiary care center. 17 combatants who sustained mine blast injuries were included in this study. Severity of foot injury was assessed as per Foot and Ankle Severity Score. After wound debridement, negative pressure wound therapy was started and foot defect was appropriately reconstructed. Following wound healing, the foot was assessed for Foot and Ankle Severity Score in terms of impairment. The patients were then suitably rehabilitated by shoe modifications, orthosis, or custom-made prosthesis. Mean age of soldiers who sustained mine blast injuries was 30.2 years. The mean Foot and Ankle Severity Score was 3.76. Temporary wound closure was achieved using negative pressure wound therapy and it prevented local and systemic infection. The defect could be reconstructed appropriately using split skin graft, regional fasciocutaneous flap, or microvascular free flap. Mean time to definitive reconstructive procedure was 16.5 days. Mean Foot and Ankle Severity Score in terms of impairment was 4.11. All soldiers could be rehabilitated and were returned to their respective units and were able to perform sedentary duties assigned to them. The negative pressure wound therapy was helpful in preventing proximal amputations due to mine blast injury and was helpful in satisfactory reconstruction of foot defects.

  2. Major bleeding during negative pressure wound/V.A.C.®--therapy for postsurgical deep sternal wound infection--a critical appraisal

    NARCIS (Netherlands)

    van Wingerden, Jan J.; Segers, Patrique; Jekel, Lilian

    2011-01-01

    Negative-pressure wound therapy, commercially known as vacuum-assisted closure (V.A.C.®) therapy, has become one of the most popular (and efficacious) interim (prior to flap reconstruction) or definite methods of managing deep sternal wound infection. Complications such as profuse bleeding, which

  3. Prophylactic negative-pressure wound therapy after cesarean is associated with reduced risk of surgical site infection: a systematic review and meta-analysis.

    Science.gov (United States)

    Yu, Lulu; Kronen, Ryan J; Simon, Laura E; Stoll, Carolyn R T; Colditz, Graham A; Tuuli, Methodius G

    2018-02-01

    The objective of the study was to assess the effect of prophylactic negative-pressure wound therapy on surgical site infections and other wound complications in women after cesarean delivery. We searched Ovid Medline, Embase, SCOPUS, Cochrane Database of Systematic Reviews, and ClinicalTrials.gov. We included randomized controlled trials and observational studies comparing prophylactic negative-pressure wound therapy with standard wound dressing for cesarean delivery. The primary outcome was surgical site infection after cesarean delivery. Secondary outcomes were composite wound complications, wound dehiscence, wound seroma, endometritis, and hospital readmission. Heterogeneity was assessed using Higgin's I 2 . Relative risks with 95% confidence intervals were calculated using random-effects models. Six randomized controlled trials and 3 cohort studies in high-risk mostly obese women met inclusion criteria and were included in the meta-analysis. Six were full-text articles, 2 published abstracts, and 1 report of trial results in ClinicalTrials.gov. Studies were also heterogeneous in the patients included and type of negative-pressure wound therapy device. The risk of surgical site infection was significantly lower with the use of prophylactic negative-pressure wound therapy compared with standard wound dressing (7 studies: pooled risk ratio, 0.45; 95% confidence interval, 0.31-0.66; adjusted risk ratio, -6.0%, 95% confidence interval, -10.0% to -3.0%; number needed to treat, 17, 95% confidence interval, 10-34). There was no evidence of significant statistical heterogeneity (I 2  = 9.9%) or publication bias (Egger P = .532). Of the secondary outcomes, only composite wound complications were significantly reduced in patients receiving prophylactic negative-pressure wound therapy compared with standard dressing (9 studies: pooled risk ratio, 0.68, 95% confidence interval, 0.49-0.94). Studies on the effectiveness of prophylactic negative-pressure wound therapy at

  4. Negative pressure of the environmental air in the cleaning area of the materials and sterilization center: a systematic review.

    Science.gov (United States)

    Ciofi-Silva, Caroline Lopes; Hansen, Lisbeth Lima; Almeida, Alda Graciele Claudio Dos Santos; Kawagoe, Julia Yaeko; Padoveze, Maria Clara; Graziano, Kazuko Uchikawa

    2016-09-01

    to analyze the scientific evidence on aerosols generated during cleaning activities of health products in the Central Service Department (CSD) and the impact of the negative pressure of the ambient air in the cleaning area to control the dispersion of aerosols to adjacent areas. for this literature systematic review the following searches were done: search guidelines, manuals or national and international technical standards given by experts; search in the portal and databases PubMed, Scopus, CINAHL and Web of Science; and a manual search of scientific articles. the five technical documents reviewed recommend that the CSD cleaning area should have a negative differential ambient air pressure, but scientific articles on the impact of this intervention were not found. The four articles included talked about aerosols formed after the use of a ultrasonic cleaner (an increased in the contamination especially during use) and pressurized water jet (formation of smaller aerosols 5μm). In a study, the aerosols formed from contaminated the hot tap water with Legionella pneumophila were evaluated. there is evidence of aerosol formation during cleanup activities in CSD. Studies on occupational diseases of respiratory origin of workers who work in CSD should be performed. analisar as evidências científicas sobre aerossóis gerados durante atividades de limpeza dos produtos para saúde no Centro de Material e Esterilização (CME) e o impacto da pressão negativa do ar ambiente na área de limpeza para controle da dispersão de aerossóis para áreas adjacentes. para essa revisão sistemática de literatura foram realizadas: busca de diretrizes, manuais ou normas técnicas nacionais e internacionais indicadas por especialistas; busca no portal e bases de dados PUBMED, SCOPUS, Cinahl e Web of Science; e busca manual de artigos científicos. Os cinco documentos técnicos analisados preconizam que na área de limpeza do CME haja diferencial negativo de pressão do ar ambiente

  5. Ginkgo biloba for intermittent claudication.

    Science.gov (United States)

    Nicolaï, Saskia P A; Kruidenier, Lotte M; Bendermacher, Bianca L W; Prins, Martin H; Stokmans, Rutger A; Broos, Pieter P H L; Teijink, Joep A W

    2013-06-06

    People with intermittent claudication (IC) suffer from pain in the muscles of the leg occurring during exercise which is relieved by a short period of rest. Symptomatic relief can be achieved by (supervised) exercise therapy and pharmacological treatments. Ginkgo biloba is a vasoactive agent and is used to treat IC. To assess the effect of Ginkgo biloba on walking distance in people with intermittent claudication. For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (March 2013) and CENTRAL (2013, Issue 2). Randomised controlled trials of Ginkgo biloba extract, irrespective of dosage, versus placebo in people with IC. Two authors independently assessed trials for selection, assessed study quality and extracted data. We extracted number of patients, mean walking distances or times and standard deviations. To standardise walking distance or time, caloric expenditures were used to express the difference between the different treadmill protocols, which were calculated from the speed and incline of the treadmill. Fourteen trials with a total of 739 participants were included. Eleven trials involving 477 participants compared Ginkgo biloba with placebo and assessed the absolute claudication distance (ACD). Following treatment with Ginkgo biloba at the end of the study the ACD increased with an overall effect size of 3.57 kilocalories (confidence interval (CI) -0.10 to 7.23, P = 0.06), compared with placebo. This translates to an increase of just 64.5 ( CI -1.8 to 130.7) metres on a flat treadmill with an average speed of 3.2 km/h. Publication bias leading to missing data or "negative" trials is likely to have inflated the effect size. Overall, there is no evidence that Ginkgo biloba has a clinically significant benefit for patients with peripheral arterial disease.

  6. Sky dancer: an intermittent system

    Science.gov (United States)

    Cros, Anne; Rodríguez Romero, Jesse Alexander; Damián Díaz Andrade, Oscar

    2009-11-01

    Sky dancers attract people sight to make advertising. What is the origin of those large vertical tubes fluctuations above an air blower? This study complements the previous one [1] about the system analysis from a dynamical system point of view. As a difference from the ``garden hose-instability'' [2], the tube shape has got ``break points''. Those ``break points'' separate the air-filled bottom tube portion from its deflated top portion. We record the tube dynamics with a high-speed videocamera simultaneously that we measure the pressure at the air blower exit. The intermittent pressure evolution displays picks when the tube fluctuates. We compare those overpressure values with the ones that appears in a rigid tube whose exit is partially obstructed. [1] F. Castillo Flores & A. Cros ``Transition to chaos of a vertical collapsible tube conveying air flow'' J. Phys.: Conf. Ser. 166, 012017 (2009). [2] A. S. Greenwald & J. Dungundji ``Static and dynamic instabilities of a propellant line'' MIT Aeroelastic and Structures Research Lab, AFOSR Sci. Report: AFOSR 67-1395 (1967).

  7. Treatment of open upper limb injuries with infection prevention and negative pressure wound therapy: a systematic review.

    Science.gov (United States)

    Ali, E; Raghuvanshi, M

    2017-12-02

    Open upper limb injuries requiring soft reconstruction can pose a dilemma for trauma surgeons when considering the treatment options. The British Orthopaedic Association and British Association of Plastic, Reconstructive and Aesthetic Surgeons Standard for Trauma (BOAST) have addressed the management of severe open lower limb fractures with the creation of the BOAST 4 guidelines. However, no such gold standard exists for the treatment of open injuries of the upper limb. Furthermore, treatment of these injuries is often more difficult and requires complicated strategies. Since the advent of negative pressure wound therapy (NPWT), there has been an improvement in wound care, though a focused review of its use in wound closure and infection prevention in the upper limb has not been published. We examine wound care management for open upper limb injuries with regard to the dressings applied, NPWT, wound closure and infection prevention. A systematic search of Medline, Cochrane and Google Scholar was performed using the key words. The key word searches were performed by two independent reviewers and 8,792 papers were found. Manuscripts between 1990 and 2010 were included, with the addition of key manuscripts before this date. Each manuscript was assessed by the two authors independently for methodology and validity Results: Approximately 120 manuscripts fulfilled selection criteria examining the influence of NPWT on open upper and lower limb injuries, and those examining infection risk in the same injuries. Of these 120 manuscripts, 28 were suitable for inclusion in the review. The systematic review is presented, allied to the BOAST 4 principles, examining the use of NPWT and the tools available for infection prevention for wounds of the upper and lower limb. The use of NPWT in conjunction with antibiotic-bead therapy improved the way in which open fractures of both the upper and lower limb are treated. Production of guidelines is warranted for the treatment of upper

  8. Economic and organizational sustainability of a negative-pressure portable device for the prevention of surgical-site complications

    Directory of Open Access Journals (Sweden)

    Foglia E

    2017-06-01

    Full Text Available Emanuela Foglia,1 Lucrezia Ferrario,1 Elisabetta Garagiola,1 Giuseppe Signoriello,2 Gianluca Pellino,3 Davide Croce,1,4 Silvestro Canonico3 1Centre for Health Economics, Social and Health Care Management - LIUC University, Castellanza, Italy; 2Department of Mental Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy; 3School of Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy; 4School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South \tAfrica Purpose: Surgical-site complications (SSCs affect patients’ clinical pathway, prolonging their hospitalization and incrementing their management costs. The present study aimed to assess the economic and organizational implications of a portable device for negative-pressure wound therapy (NPWT implementation, compared with the administration of pharmacological therapies alone for preventing surgical complications in patients undergoing general, cardiac, obstetrical–gynecological, or orthopedic surgical procedures.Patients and methods: A total of 8,566 hospital procedures, related to the year 2015 from one hospital, were evaluated considering infection risk index, occurrence rates of SSCs, drug therapies, and surgical, diagnostic, and specialist procedures and hematological exams. Activity-based costing and budget impact analyses were implemented for the economic assessment.Results: Patients developing an SSC absorbed i 64.27% more economic resources considering the length of stay (€ 8,269±2,096 versus € 5,034±2,901, p<0.05 and ii 42.43% more economic resources related to hematological and diagnostic procedures (€ 639±117 versus € 449±72, p<0.05. If the innovative device had been used over the 12-month time period, it would have decreased the risk of developing SSCs; the hospital would have realized an average reduction in health care expenditure equal to −0.69% (−€ 483

  9. The Challenge of Providing Safe Water with an Intermittently Supplied Piped Water Distribution System

    Science.gov (United States)

    Kumpel, E.; Nelson, K. L.

    2012-12-01

    An increasing number of urban residents in low- and middle-income countries have access to piped water; however, this water is often not available continuously. 84% of reporting utilities in low-income countries provide piped water for fewer than 24 hours per day (van den Berg and Danilenko, 2010), while no major city in India has continuous piped water supply. Intermittent water supply leaves pipes vulnerable to contamination and forces households to store water or rely on alternative unsafe sources, posing a health threat to consumers. In these systems, pipes are empty for long periods of time and experience low or negative pressure even when water is being supplied, leaving them susceptible to intrusion from sewage, soil, or groundwater. Households with a non-continuous supply must collect and store water, presenting more opportunities for recontamination. Upgrading to a continuous water supply, while an obvious solution to these challenges, is currently out of reach for many resource-constrained utilities. Despite its widespread prevalence, there are few data on the mechanisms causing contamination in an intermittent supply and the frequency with which it occurs. Understanding the impact of intermittent operation on water quality can lead to strategies to improve access to safe piped water for the millions of people currently served by these systems. We collected over 100 hours of continuous measurements of pressure and physico-chemical water quality indicators and tested over 1,000 grab samples for indicator bacteria over 14 months throughout the distribution system in Hubli-Dharwad, India. This data set is used to explore and explain the mechanisms influencing water quality when piped water is provided for a few hours every 3-5 days. These data indicate that contamination occurs along the distribution system as water travels from the treatment plant to reservoirs and through intermittently supplied pipes to household storage containers, while real

  10. Intermittent hypoxia and neurorehabilitation.

    Science.gov (United States)

    Gonzalez-Rothi, Elisa J; Lee, Kun-Ze; Dale, Erica A; Reier, Paul J; Mitchell, Gordon S; Fuller, David D

    2015-12-15

    In recent years, it has become clear that brief, repeated presentations of hypoxia [i.e., acute intermittent hypoxia (AIH)] can boost the efficacy of more traditional therapeutic strategies in certain cases of neurologic dysfunction. This hypothesis derives from a series of studies in animal models and human subjects performed over the past 35 yr. In 1980, Millhorn et al. (Millhorn DE, Eldridge FL, Waldrop TG. Respir Physiol 41: 87-103, 1980) showed that electrical stimulation of carotid chemoafferent neurons produced a persistent, serotonin-dependent increase in phrenic motor output that outlasts the stimulus for more than 90 min (i.e., a "respiratory memory"). AIH elicits similar phrenic "long-term facilitation" (LTF) by a mechanism that requires cervical spinal serotonin receptor activation and de novo protein synthesis. From 2003 to present, a series of studies demonstrated that AIH can induce neuroplasticity in the injured spinal cord, causing functional recovery of breathing capacity after cervical spinal injury. Subsequently, it was demonstrated that repeated AIH (rAIH) can induce recovery of limb function, and the functional benefits of rAIH are greatest when paired with task-specific training. Since uncontrolled and/or prolonged intermittent hypoxia can elicit pathophysiology, a challenge of intermittent hypoxia research is to ensure that therapeutic protocols are well below the threshold for pathogenesis. This is possible since many low dose rAIH protocols have induced functional benefits without evidence of pathology. We propose that carefully controlled rAIH is a safe and noninvasive modality that can be paired with other neurorehabilitative strategies including traditional activity-based physical therapy or cell-based therapies such as intraspinal transplantation of neural progenitors. Copyright © 2015 the American Physiological Society.

  11. Intermittency in Complex Flows

    Science.gov (United States)

    Ben Mahjoub, Otman; Redondo, Jose M.

    2017-04-01

    Experimental results of the complex turbulent wake of a cilinder in 2D [1] and 3D flows [2] were used to investigate the scaling of structure functions, similar research was also performed on wave propagation and breaking in the Ocean [3], in the the stratified Atmosphere (ABL) [4] and in a 100large flume (UPC) for both regular and irregular waves, where long time series of waves propagating and generating breaking turbulence velocity rms and higher order measurements were taken in depth. [3,5] by means of a velocimeter SONTEK3-D. The probability distribution functions of the velocity differences and their non Gaussian distribution related to the energy spectrum indicate that irregularity is an important source of turbulence. From Kolmogorov's K41 and K61 intermittency correction: the p th-order longitudinal velocity structure function δul at scale l in the inertial range of three-dimensional fully developed turbulence is related by ⟨δup⟩ = ⟨(u(x+ l)- u(x))p⟩ ˜ ɛp0/3lp/3 l where ⟨...⟩ represents the spatial average over flow domain, with ɛ0 the mean energy dissipation per unit mass and l is the separation distance. The importance of the random nature of the energy dissipation led to the K62 theory of intermittency, but locality and non-homogeneity are key issues. p p/3 p/3 ξd ⟨δul⟩ ˜ ⟨ɛl ⟩l ˜ l and ξp = p 3 + τp/3 , where now ɛl is a fractal energy dissipation at scale l, τp/3 is the scaling of and ξp is the scaling exponent of the velocity structure function of order p. Both in K41 and K62, the structure functions of third order related to skewness is ξ3 = 1. But this is not true either. We show that scaling exponents ξp do deviate from early studies that only investigated homogeneous turbulence, where a large inertial range dominates. The use of multi-fractal analysis and improvements on Structure function calculations on standard Enhanced mixing is an essential property of turbulence and efforts to alter and to control

  12. Spectral components of human cardiovascular responses to step changes in Lower Body Negative Pressure (LBNP) before and after 22 hour of 6 deg head down bed rest

    Science.gov (United States)

    Knapp, C. F.; Evans, J. M.; Grande, K. J.; Murphy, C. D.; Patwardhan, A. R.

    1992-01-01

    Changes in autonomic outflow to peripheral organs during the development of bedrest induced orthostatic intolerance have not been determined. Recent studies have indicated that spectral analysis provides an indirect assessment of these changes. Eight male subjects were studied before and after 22 hours of 6 degree head down bedrest plus Lasix (40 mg. P.P.). Cardiovascular spectra (using an autoregressive technique) were determined for heart rate (HR, ECG), arterial pressure (AP, Finapres), radial artery flow (RF, Hokansen) and respiration rate (RR, BoMed). Spectra were obtained from 2.5 minute segments during control, lower body negative pressure (minus 10, 20, 30, 40, 50 mmHg) and recovery. Bedrest increased HR spectra power in the low frequency (.001 to .041 Hz) range, increased RF power in the low and mid (.04 to .18 Hz) range and increased AP power in the high (.18 to .50 Hz) frequency range. Increasing levels of lower body negative pressure decreased HR power and increased RF power in the high frequency range and decreased AP power in the low frequency range. Since spectral power of HR in the high frequency range has been shown to indicate parasympathetically mediated regulation and power in the low and mid frequency ranges indicates a sympathetic / parasympathetic mixture, then both bedrest and lower body negative pressure appeared to shift sympathetic / parasympathetic balance toward sympathetic regulation of HR. The interpretation of the spectral content of AP and RF with respect to their autonomic origins remains unclear.

  13. Cracked rocks with positive and negative Poisson's ratio: real-crack properties extracted from pressure dependence of elastic-wave velocities

    Science.gov (United States)

    Zaitsev, Vladimir Y.; Radostin, Andrey V.; Dyskin, Arcady V.; Pasternak, Elena

    2017-04-01

    We report results of analysis of literature data on P- and S-wave velocities of rocks subjected to variable hydrostatic pressure. Out of about 90 examined samples, in more than 40% of the samples the reconstructed Poisson's ratios are negative for lowest confining pressure with gradual transition to the conventional positive values at higher pressure. The portion of rocks exhibiting negative Poisson's ratio appeared to be unexpectedly high. To understand the mechanism of negative Poisson's ratio, pressure dependences of P- and S-wave velocities were analyzed using the effective medium model in which the reduction in the elastic moduli due to cracks is described in terms of compliances with respect to shear and normal loading that are imparted to the rock by the presence of cracks. This is in contrast to widely used descriptions of effective cracked medium based on a specific crack model (e.g., penny-shape crack) in which the ratio between normal and shear compliances of such a crack is strictly predetermined. The analysis of pressure-dependences of the elastic wave velocities makes it possible to reveal the ratio between pure normal and shear compliances (called q-ratio below) for real defects and quantify their integral content in the rock. The examination performed demonstrates that a significant portion (over 50%) of cracks exhibit q-ratio several times higher than that assumed for the conventional penny-shape cracks. This leads to faster reduction of the Poisson's ratio with increasing the crack concentration. Samples with negative Poisson's ratio are characterized by elevated q-ratio and simultaneously crack concentration. Our results clearly indicate that the traditional crack model is not adequate for a significant portion of rocks and that the interaction between the opposite crack faces leading to domination of the normal compliance and reduced shear displacement discontinuity can play an important role in the mechanical behavior of rocks.

  14. Effectiveness of negative pressure wound therapy/closed incision management in the prevention of post-surgical wound complications: a systematic review and meta-analysis.

    Science.gov (United States)

    Sandy-Hodgetts, Kylie; Watts, Robin

    2015-01-01

    The treatment of post-surgical wound complications, such as surgical site infections and surgical wound dehiscence, generates a significant burden for patients and healthcare systems. The effectiveness of negative pressure wound therapy has been under investigation but to date no systematic review has been published in relation to its effectiveness in the prevention of surgical wound complications. To identify the effectiveness of negative pressure wound therapy in the prevention of post-surgical wound complications in adults with a closed surgical incision compared to standard surgical dressings. Male and female adults who have had negative pressure wound therapy applied to their surgical incision following a procedure in one of the following areas: trauma, cardiothoracic, orthopedic, abdominal, or vascular surgery.The intervention of interest was the use of negative pressure wound therapy directly over an incision following a surgical procedure; the comparator was standard surgical dressings.Both experimental and epidemiological study designs, including randomized controlled trials, pseudo-randomized trials, quasi-experimental studies, before and after studies, prospective and retrospective cohort studies, case control studies, and analytical cross sectional studies were sought.The primary outcome was the occurrence of post-surgical wound infection or dehiscence as measured by the following: surgical site infections - superficial and deep; surgical wound dehiscence; wound pain; wound seroma; wound hematoma. Published and unpublished studies in English from 1990 to 2013 were identified by searching a variety of electronic databases. Reference lists of all papers selected for retrieval were then searched for additional studies. Papers selected for retrieval were assessed by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute Meta-Analysis of

  15. Metabolic Effects of Intermittent Fasting.

    Science.gov (United States)

    Patterson, Ruth E; Sears, Dorothy D

    2017-08-21

    The objective of this review is to provide an overview of intermittent fasting regimens, summarize the evidence on the health benefits of intermittent fasting, and discuss physiological mechanisms by which intermittent fasting might lead to improved health outcomes. A MEDLINE search was performed using PubMed and the terms "intermittent fasting," "fasting," "time-restricted feeding," and "food timing." Modified fasting regimens appear to promote weight loss and may improve metabolic health. Several lines of evidence also support the hypothesis that eating patterns that reduce or eliminate nighttime eating and prolong nightly fasting intervals may result in sustained improvements in human health. Intermittent fasting regimens are hypothesized to influence metabolic regulation via effects on (a) circadian biology, (b) the gut microbiome, and (c) modifiable lifestyle behaviors, such as sleep. If proven to be efficacious, these eating regimens offer promising nonpharmacological approaches to improving health at the population level, with multiple public health benefits.

  16. Major bleeding during negative pressure wound/V.A.C.® - therapy for postsurgical deep sternal wound infection - a critical appraisal

    Directory of Open Access Journals (Sweden)

    Segers Patrique

    2011-09-01

    Full Text Available Abstract Negative-pressure wound therapy, commercially known as vacuum-assisted closure (V.A.C.® therapy, has become one of the most popular (and efficacious interim (prior to flap reconstruction or definite methods of managing deep sternal wound infection. Complications such as profuse bleeding, which may occur during negative-pressure therapy but not necessarily due to it, are often attributed to a single factor and reported as such. However, despite the wealth of clinical experience internationally available, information regarding certain simple considerations is still lacking. Garnering information on all the factors that could possibly influence the outcome has become more difficult due to a (fortunate decrease in the incidence of deep sternal wound infection. If more insight is to be gained from fewer clinical cases, then various potentially confounding factors should be fully disclosed before complications can be attributed to the technique itself or improvements to negative-pressure wound therapy for deep sternal wound infection can be accepted as evidence-based and the guidelines for its use adapted. The authors propose the adoption of a simple checklist in such cases.

  17. Can single use negative pressure wound therapy be an alternative method to manage keloid scarring? A preliminary report of a clinical and ultrasound/colour-power-doppler study.

    Science.gov (United States)

    Fraccalvieri, Marco; Sarno, Antonino; Gasperini, Stefano; Zingarelli, Enrico; Fava, Raffaella; Salomone, Marco; Bruschi, Stefano

    2013-06-01

    Keloid scarring represents a pathological healing where primary healing phenomenon is deviated from normal. Pico is a single use negative pressure wound therapy system originally introduced to manage open or just closed wounds. Pico dressing is made of silicone, and distributes an 80 mmHg negative pressure across wound bed. Combination of silicon layer and continuous compression could be a valid method to manage keloid scarring. Since November 2011, three patients were enrolled and evaluated before negative pressure treatment, at end of treatment (1 month) and 2 months later, through Vancouver Scar Scale (VSS), Visual Analog Scale (VAS) and a scoring system for itching. Ultrasound (US) and colour-power-doppler (CPD) examination was performed to evaluate thickness and vascularisation of the scar. One patient was discharged from study after 1 week. In last two patients, VSS, VAS and itching significantly improved after 1 month therapy and the results were stable after 2 months without any therapy. At end of therapy, the 'appearance of palisade vessels' disappeared in both cases at CPD exam; US showed a thickness reduction (average 43·8%). We propose a well-tolerated, non invasive treatment to manage keloid scarring. Prospective studies are necessary to investigate whether these preliminary observations are confirmed. © 2012 The Authors. International Wound Journal © 2012 John Wiley & Sons Ltd and Medicalhelplines.com Inc.

  18. A Risk Analysis Methodology to Address Human and Organizational Factors in Offshore Drilling Safety: With an Emphasis on Negative Pressure Test

    Science.gov (United States)

    Tabibzadeh, Maryam

    According to the final Presidential National Commission report on the BP Deepwater Horizon (DWH) blowout, there is need to "integrate more sophisticated risk assessment and risk management practices" in the oil industry. Reviewing the literature of the offshore drilling industry indicates that most of the developed risk analysis methodologies do not fully and more importantly, systematically address the contribution of Human and Organizational Factors (HOFs) in accident causation. This is while results of a comprehensive study, from 1988 to 2005, of more than 600 well-documented major failures in offshore structures show that approximately 80% of those failures were due to HOFs. In addition, lack of safety culture, as an issue related to HOFs, have been identified as a common contributing cause of many accidents in this industry. This dissertation introduces an integrated risk analysis methodology to systematically assess the critical role of human and organizational factors in offshore drilling safety. The proposed methodology in this research focuses on a specific procedure called Negative Pressure Test (NPT), as the primary method to ascertain well integrity during offshore drilling, and analyzes the contributing causes of misinterpreting such a critical test. In addition, the case study of the BP Deepwater Horizon accident and their conducted NPT is discussed. The risk analysis methodology in this dissertation consists of three different approaches and their integration constitutes the big picture of my whole methodology. The first approach is the comparative analysis of a "standard" NPT, which is proposed by the author, with the test conducted by the DWH crew. This analysis contributes to identifying the involved discrepancies between the two test procedures. The second approach is a conceptual risk assessment framework to analyze the causal factors of the identified mismatches in the previous step, as the main contributors of negative pressure test

  19. Mathematical analysis of intermittent gas injection model in oil production

    Science.gov (United States)

    Tasmi, Silvya, D. R.; Pudjo, S.; Leksono, M.; Edy, S.

    2016-02-01

    Intermittent gas injection is a method to help oil production process. Gas is injected through choke in surface and then gas into tubing. Gas forms three areas in tubing: gas column area, film area and slug area. Gas column is used to propel slug area until surface. A mathematical model of intermittent gas injection is developed in gas column area, film area and slug area. Model is expanding based on mass and momentum conservation. Using assume film thickness constant in tubing, model has been developed by Tasmi et. al. [14]. Model consists of 10 ordinary differential equations. In this paper, assumption of pressure in gas column is uniform. Model consist of 9 ordinary differential equations. Connection of several variables can be obtained from this model. Therefore, dynamics of all variables that affect to intermittent gas lift process can be seen from four equations. To study the behavior of variables can be analyzed numerically and mathematically. In this paper, simple mathematically analysis approach is used to study behavior of the variables. Variables that affect to intermittent gas injection are pressure in upstream valve and in gas column. Pressure in upstream valve will decrease when gas mass in valve greater than gas mass in choke. Dynamic of the pressure in the gas column will decrease and increase depending on pressure in upstream valve.

  20. Intermittent claudication--surgical reconstruction or physical training? A prospective randomized trial of treatment efficiency.

    Science.gov (United States)

    Lundgren, F; Dahllöf, A G; Lundholm, K; Scherstén, T; Volkmann, R

    1989-01-01

    This study reports the initial evaluation of treatment efficiency in 75 patients with intermittent claudication who were randomized to three treatment groups: 1) reconstructive surgery, 2) reconstructive surgery with subsequent physical training, and 3) physical training alone. Before treatment, there were no statistically significant differences between the groups in age, sex, smoking habits, symptom duration of claudication, ankle-arm blood pressure quotient (ankle-index), maximal plethysmographic calf blood flow, symptom-free and maximal walking distance, the history of other atherosclerotic manifestations or in the medical treatment. The walking performance was improved in all three groups at follow-up 13 +/- 0.5 months after randomization. Surgery was most effective, but the addition of training to surgery improved the symptom-free walking distance even further. In pooled observations of the three groups, age, symptom duration, and a history of myocardial ischemic disease correlated negatively with walking performance after treatment. In the operated group, the duration of claudication and a history of myocardial ischemic disease correlated negatively with the walking performance. This was not the case when patients were censored if limited by other symptoms than intermittent claudication after treatment. In the trained group, the duration of claudication correlated negatively to symptom-free and maximal walking distance. Ankle-index and maximal plethysmographic calf blood flow after treatment and the change of these variables with treatment correlated positively with both symptom-free and maximal walking distance when results were pooled for all patients. Although this mainly was a consequence of the improved blood flow after surgery, the change of maximal plethysmographic calf blood flow also correlated with symptom-free but not with maximal walking distance in the trained group. The results demonstrate that, compared with physical training alone, operation

  1. [Influence of different inner dressings in negative-pressure wound therapy on escharectomy wound of full-thickness burn rabbits].

    Science.gov (United States)

    Lin, J H; Chen, J; Xue, D J; Huang, W X; Su, G L

    2017-07-20

    Objective: To explore the influence of different inner dressings in negative-pressure wound therapy (NPWT) on escharectomy wound of full-thickness burn rabbits. Methods: Eighteen Japanese white rabbits were inflicted with full-thickness burn on unilateral back. They were divided into polymer dressing group (PD), biological dressing group (BD), and silver biological dressing group (SBD), according to the random number table, with 6 rabbits in each group. On 3 days post burn, the wounds were performed with escharectomy, and then wounds of rabbits in group PD were covered with polyurethane foam. Wounds of rabbits in group BD were covered with porcine acellular dermal matrix (ADM) and wounds of rabbits in group SBD were covered with silver porcine ADM. Then continuous NPWT was performed on rabbits of the three groups for 7 days. Immediately after surgery and on post surgery day (PSD) 7, general observation of wound was conducted and tissue around the wound was harvested for determination of dry to wet weight ratio. The content of bacteria was counted and the content of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and IL-6 in wound was determined by enzyme-linked immunosorbent assay. Fibroblasts in wound were counted after Masson staining and number of microvessels was counted after CD31 antibody immunohistochemical staining. Data were processed with analysis of variance for repeated measurement, LSD- t test, paired samples t test, and Bonferroni correction. Results: (1) Immediately after surgery, there was no granulation tissue in basal wound of rabbits in the three groups, with rich blood supply and obvious edema. On PSD 7, much granulation tissue was found in basal wound of rabbits in the three groups, with no or mild edema and no obvious redness and swelling in wound edge. (2) There were no significant differences in dry to wet weight ratios of tissue around the wound among and within the three groups immediately after surgery and on PSD 7 (with F

  2. Intermittent claudication in a professional rugby player.

    Science.gov (United States)

    Bray, A E; Lewis, W A

    1992-04-01

    Intermittent claudication in a professional rugby player is described. The typical features of a delayed and difficult diagnosis of an external iliac artery stenosis were found. The noninvasive diagnostic protocol used to investigate this young patient with a minimal arterial lesion enabled accurate localization and angioplasty to be performed at the same time as diagnostic angiography. The patient was symptom free with normal arterial pressures on follow-up. It is suggested that appropriate noninvasive investigations should be performed before angiography in young people with minimal lesions.

  3. Peripheral Microvascular Responses to Whole-Body Tilting, G(z) Centrifugation, and Lower Body Negative Pressure Stresses in Humans

    Science.gov (United States)

    Breit, G. A.; Watenpaugh, D. E.; Buckley, T. M.; Ballard, R. E.; Murthy, G.; Hargens, A. R.

    1994-01-01

    The response of the cutaneous microcirculation to orthostatic stress varies along the length of the body due to the interaction of central controls with regional responses to local blood pressure. We hypothesize that artificial orthostatic stresses such as Gz centrifugation and LBNP differ from whole-body tilting in terms of the distribution of microvascular blood flow. Cutaneous microvascular flows were measured by laser Doppler flowmetry at the neck, thigh, and leg of 15 normal subjects. Volunteers underwent stepwise head-up tilt (HUT) and short- and long-arm centrifugation protocols from supine control (0 Gz) to 0.2, 0.4, 0.6, 0.8, 1.0, 0.8, 0.6, 0.4, 0.2, and 0 Gz at the feet, for 30-s periods with 10-s transitions between levels. The same subjects underwent a corresponding supine LBNP protocol, up to 100 mmHg (in 20 mmHg increments) and back to zero pressure, which produced transmural pressure across blood vessels in the foot approximately equal to the HUT protocol. In general, application of all orthostatic stresses produced significant flow reductions in the lower body (p less than 0.05) and inconsistent changes in the neck. At low levels of each stress (0.4 Gz, 40 mmHg), LBNP generated the greatest relative reduction in flow in the lower body (-66.9+/-5.7%, thigh; -60.6 +/-5.7%, leg, mean +/- SE). HUT caused a less severe flow reduction than LBNP at the thigh and leg (-39.9 +/- 8.1% and -55.9+/-4.8%), while the effects induced by both forms of centrifugation were the least profound. Higher levels of each stress generally resulted in similar responses. These responses exhibit a consistent relationship to hypothesized changes in local microvascular transmural pressure, suggesting that myogenic and veno-arteriolar reflexes play a significant role in determining microvascular perfusion during orthostatic stress.

  4. Combined non-adaptive light and smell stimuli lowered blood pressure, reduced heart rate and reduced negative affect.

    Science.gov (United States)

    Dong, Shan; Jacob, Tim J C

    2016-03-15

    Bright light therapy has been shown to have a positive impact on seasonal affective disorder (SAD), depression and anxiety. Smell has also has been shown to have effects on mood, stress, anxiety and depression. The objective of this study was to investigate the effect of the combination of light and smell in a non-adaptive cycle. Human subjects were given smell (lemon, lavender or peppermint) and light stimuli in a triangular wave (60scycle) for 15min. Blood pressure and heart rate were monitored before and after each session for 5 consecutive days and a Profile of Mood States (POMS) test was administered before and after the sensory stimulation on days 1, 3 and 5. The light-smell stimulus lowered blood pressure, both systolic and diastolic, and reduced heart rate for all odours compared to control. Of the two sensory stimuli, the odour stimulus contributed most to this effect. The different aromas in the light-smell combinations could be distinguished by their different effects on the mood factors with lemon inducing the greatest mood changes in Dejection-Depression, Anger-Hostility, Tension-Anxiety. In conclusion, combined light and smell stimulation was effective in lowering blood pressure, reducing heart rate and improving mood. The combination was more effective than either smell or light stimuli alone, suggesting that a light-smell combination would be a more robust and efficacious alternative treatment for depression, anxiety and stress. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Intermedia and Intermittency

    Directory of Open Access Journals (Sweden)

    Veres Bálint

    2014-12-01

    Full Text Available It is commonly known that medial reflections have been initiated by attempts to secure the borders of discrete medial forms and to define the modus operandi of each essentialized medial area. Later on, the focus of study has shifted to plurimedial formations and the interactions between predefined medial genres. In the last few decades, taxonomic approaches to various multi-, inter-, and transmedial phenomena dominated the discussions, which offered invaluable support in mapping the terrain, but at the same time hindered the analysis of the ephemeral, time-dependent aspects of plurimedial operations. While we explore the properties of each medial configuration, we lose sight of the actual historical drivers that produce ever-new configurations. My thesis is that any discourse on intermediality should be paralleled by a discourse on cultural intermittency, and consequently, media studies should involve an approach that focuses on the “ecosystem” of the constantly renewing media configurations from the point of view of their vitalizing potential and capability to trigger heightened experiences. This approach draws much inspiration from K. Ludwig Pfeiffer’s media anthropology that gives orientation in my paper.

  6. Coho salmon dependence on intermittent streams.

    Science.gov (United States)

    P.J. Wigington; J.L. Ebersole; M.E. Colvin; S.G. Leibowitz; B. Miller; B. Hansen; H. Lavigne; D. White; J.P. Baker; M.R. Church; J.R. Brooks; M.A. Cairns; J.E. Compton

    2006-01-01

    In this paper, we quantify the contributions of intermittent streams to coho salmon production in an Oregon coastal watershed. We provide estimates of (1) proportion of spawning that occurred in intermittent streams, (2) movement of juveniles into intermittent streams, (3) juvenile survival in intermittent and perennial streams during winter, and (4) relative size of...

  7. Management of intermittent angle closure glaucoma with Nd: yag laser iridotomy as a primary procedure

    International Nuclear Information System (INIS)

    Ahmed, M.

    2006-01-01

    To assess the efficacy and complications of Nd: YAG laser iridotomy in patients with intermittent (sub-acute) angle closure glaucoma. Twenty-five eyes of twenty-three patients with periodic (intermittent) angle closure, selected in outpatient department, were kept on pilocarpine until YAG laser iridotomy was performed. After YAG laser iridotomy oral acetazolamide and topical dexamethasone was used to control post laser rise of IOP and inflammation respectively. Patency of iridotomy was confirmed and intra-ocular pressure was measured one hour after the procedure. Immediate complication, if any, was noted. Follow-up was done for six months. Prophylactic laser iridotomy was done in fellow eye with occludable angle. Levene's test for equality of variance and t-test for equality of means were used for statistical analysis. This study revealed a significant difference in IOP before and after YAG laser iridotomy (p = .002). Complete follow-up of 6 months was possible in 25 eyes of 23 subjects. After YAG Laser iridotomy, 21 (84%) eyes showed negative provocative test, intraocular pressure below 19mm Hg without medication and anterior chamber angle no more occludable and were labeled successful. Iridotomy remained patent in 96% of eyes. Iridotomy failed to reduce IOP in 4 (16%) eyes. The complications were minimal and transient. (author)

  8. Theory of photostructural changes in glasses with negative-U centers: dependencies of steady-state photodarkening on gap-light intensity and frequency, pressure and temperature

    International Nuclear Information System (INIS)

    Klinger, M.I.

    2004-01-01

    A theory is presented of a mechanism for the photostructural changes observed in semiconducting glasses. The theory takes into account that in these materials negative-U centers are the basic charge carriers, and gap-light generated excited states of such centers are accompanied by metastable 'defects' in the original structure, which can be identified as the photostructural changes. The theory gives rise to a consistent interpretation, and some predictions, of dependencies of the steady-state photodarkening on gap-light intensity and frequency, pressure and temperature

  9. Effect of negative pressure therapy on repair of soft tissues of the lower extremities in patients with neuropathic and neuroischaemic forms of diabetic foot syndrome

    Directory of Open Access Journals (Sweden)

    Ekaterina Leonidovna Zaytseva

    2014-06-01

    Full Text Available AimTo evaluate the efficiency of topical negative pressure wound therapy (NPWT compared with standard therapy for the regeneration of the soft tissues of the lower extremities in patients with diabetic foot syndrome.Materials and MethodsThe effects of negative pressure therapy on the clinical (size, tissue oxygenation, histological (light microscopy and immunohistochemical (CD68, MMP-9, TIMP-1 aspects of repair of the soft tissue of the lower extremities in patients with diabetes mellitus were compared with those of standard treatment. Thirty-one patients with diabetic foot ulcers were included in the study from the moment of debridement until the plastic closure of the wound. During the perioperative period, 13 patients received NPWT (-90 to -120 mmHg and 18 patients received standard therapy.ResultsA reduction of the wound area (26.6%±17.2% and the depth of the defects (40.5%±25.6% were achieved with negative pressure therapy compared with baseline data. In the control group, the corresponding values were 25.3%±19.4% and 21.8%±21.6%, respectively. The results of transcutaneous oximetry showed a greater increase in the level of local hemodynamics in the study group (p <0.04. An important criterion for wound preparation for a plastic closure is filling it with granulation tissue by more than 75%. In the study group, 95% of patients had wounds filled with 89.9%±17% of abundant granulation tissue. The histological data of the study group show a significant reduction of oedema by 80% (p <0.05, improved extracellular matrix organization (p <0.05, 90% (p <0.05 dissolution of inflammatory infiltrate and the formation of healthy granulation tissue (p <0.05. Immunohistochemical analysis demonstrated a significant decrease in the number of macrophages in the dermis (CD68 expression (p <0.05. In both groups, the level of MMP-9 was decreased. However, the ratio of MMP-9:TIMP-1 was lower in the study group (p <0.05.ConclusionThe findings suggest that

  10. A compare between myocardial topical negative pressure levels of -25 mmHg and -50 mmHg in a porcine model

    DEFF Research Database (Denmark)

    Lindstedt, Sandra; Paulsson, Per; Mokhtari, Arash

    2008-01-01

    Topical negative pressure (TNP), widely used in wound therapy, is known to stimulate wound edge blood flow, granulation tissue formation, angiogenesis, and revascularization. We have previously shown that application of a TNP of -50 mmHg to the myocardium significantly increases microvascular blood...... flow in the underlying tissue. We have also shown that a myocardial TNP levels between -75 mmHg and -150 mmHg do not induce microvascular blood flow changes in the underlying myocardium. The present study was designed to elucidate the difference between -25 mmHg and -50 mmHg TNP on microvascular flow...

  11. Observational study on efficacy of negative expiratory pressure test proposed as screening for obstructive sleep apnea syndrome among commercial interstate bus drivers - protocol study

    Directory of Open Access Journals (Sweden)

    Hirata Raquel P

    2011-12-01

    Full Text Available Abstract Background Obstructive sleep apnea (OSA is a respiratory disease characterized by the collapse of the extrathoracic airway and has important social implications related to accidents and cardiovascular risk. The main objective of the present study was to investigate whether the drop in expiratory flow and the volume expired in 0.2 s during the application of negative expiratory pressure (NEP are associated with the presence and severity of OSA in a population of professional interstate bus drivers who travel medium and long distances. Methods/Design An observational, analytic study will be carried out involving adult male subjects of an interstate bus company. Those who agree to participate will undergo a detailed patient history, physical examination involving determination of blood pressure, anthropometric data, circumference measurements (hips, waist and neck, tonsils and Mallampati index. Moreover, specific questionnaires addressing sleep apnea and excessive daytime sleepiness will be administered. Data acquisition will be completely anonymous. Following the medical examination, the participants will perform a spirometry, NEP test and standard overnight polysomnography. The NEP test is performed through the administration of negative pressure at the mouth during expiration. This is a practical test performed while awake and requires little cooperation from the subject. In the absence of expiratory flow limitation, the increase in the pressure gradient between the alveoli and open upper airway caused by NEP results in an increase in expiratory flow. Discussion Despite the abundance of scientific evidence, OSA is still underdiagnosed in the general population. In addition, diagnostic procedures are expensive, and predictive criteria are still unsatisfactory. Because increased upper airway collapsibility is one of the main determinants of OSA, the response to the application of NEP could be a predictor of this disorder. With the

  12. Intermittent Testicular Torsion

    African Journals Online (AJOL)

    2017-12-05

    , presence of abnormal testicular lie in otherwise normal testes, absence of urinary symptoms, and negative urine cultures. This diagnosis was confirmed by resolution of symptoms following bilateral orchidopexy. All patients ...

  13. Abdominal Cavity Eventration Treated by Means of the "Open Abdomen" Technique Using the Negative Pressure Therapy System--Case Report and Literature Review.

    Science.gov (United States)

    Trzeciak, Piotr W; Porzeżyńska, Joanna; Ptasińska, Karolina; Walczak, Dominik A

    2015-11-01

    Wound dehiscence is a surgical complication in which the wound ruptures along the surgical suture with abdominal cavity bowel displacement. It is observed in 0.2-6% of operated patients. The extensive wound is a gateway for infection. Moreover, increased secretion of serous fluid induces a hygienic problem and may lead to secondary skin infections or bedsores. The negative pressure wound therapy (NPWT) system is an innovative therapeutic method. It perfectly executes the TIME strategy, receiving more and more recognition. The study presented a case of a 62-year old male patient after several consecutive wound dehiscence episodes who was primarily treated for rectal cancer by means of low anterior resection of the rectum. Due to acute respiratory insufficiency after several operations, wound necrosis with dehiscence was observed. Considering the high risk of perioperative death we abandoned surgical treatment and introduced conservative management using negative pressure wound therapy until the patient's health improved. Literature regarding the above-mentioned issue was also reviewed.

  14. The SNaP™ Wound Care System: A Case Series Using a Novel Ultraportable Negative Pressure Wound Therapy Device for the Treatment of Diabetic Lower Extremity Wounds

    Science.gov (United States)

    Lerman, Bruce; Oldenbrook, Leslie; Ryu, Justin; Fong, Kenton D.; Schubart, Peter J.

    2010-01-01

    Although there is significant evidence supporting the use of negative pressure wound therapy (NPWT) for the treatment of lower extremity diabetic ulcers, currently available electrically powered NPWT systems are not ideally suited for treating smaller diabetic foot ulcers. The Smart Negative Pressure (SNaP™) Wound Care System is a novel, ultraportable device that delivers NPWT without the use of an electrically powered pump. It was specifically designed to meet the wound care needs of patients with diabetes. The SNaP System is compact, silent, mobile, easy-to-use, and available off-the-shelf. It is fully disposable and may offer other important benefits over electrically powered systems to both the clinician and patient. We review the evidence for use of NPWT for the treatment of diabetic wounds and discuss the potential benefits of this new NPWT technology for patients with diabetes. We also present a case series of four difficult lower extremity diabetic ulcers that were successfully treated with the SNaP System. This study suggests that the SNaP System may be a useful addition to the armamentarium of the diabetic wound care clinician. PMID:20663444

  15. Stagnations of increasing trends in negative pressure with repeated cavitation in water/metal Berthelot tubes as a result of mechanical sealing

    International Nuclear Information System (INIS)

    Hiro, Kazuki; Ohde, Yoshihito; Tanzawa, Yasutoshi

    2003-01-01

    To investigate effects of mechanical sealing on negative pressures in water/metal tube Berthelot systems, trends in negative pressure are observed through runs of temperature cycles below 90 deg. C in two systems made of metals having small amounts of gas inclusions. The first system is a pre-degassed all-stainless-steel tube/plug system. The steel is a special product for vacuum engineering. The second is the same tube sealed with plugs made of silver solidified one-dimensionally in a vacuum furnace. A new type of trend, stagnation for intermediate cycles is found in both systems so long as sealing distortion of each plug is small in amount. The stagnation period for the first system is longer than that for the second one. A metallurgical mechanism of a gas-being-replenished crevice model is proposed: distorted parts of metals undergo heat-treatment during runs of temperature cycles, and the heat-treatment enhances the rates of impurity gas transports to crevices on the metal surface where cavitation occurs, and the transport causes the stagnation for cycles during which the rates are still high

  16. Use of a portable, single-use negative pressure wound therapy device in home care patients with low to moderately exuding wounds: a case series.

    Science.gov (United States)

    Hurd, Theresa; Trueman, Paul; Rossington, Alan

    2014-03-01

    Negative pressure wound therapy (NPWT) is widely used in the management of acute and chronic wounds. The purpose of this 8-week study was to evaluate outcomes of using a new canisterless, portable, single-use NPWT system in patients with wounds treated in a Canadian community healthcare setting. The device is designed to provide negative pressure at 80±20 mm Hg, 24 hours a day of continuous usage, for a maximum wear time of 7 days. Data on wound outcomes, including exudate levels, wound appearance, and wound area, were collected weekly by a Registered Nurse as part of routine practice. When treatment was discontinued, patients and nurses were asked to rate their satisfaction with the device. Data from patients who had used a conventional NPWT device to manage their wounds were retrospectively abstracted from their medical records. In the prospective study, conducted between October 2011 and July 2012, 326 patients (median age=61 years; range 17-91 years) with wounds of mixed etiology (53 pressure ulcers, 21 venous leg ulcers, 16 diabetic foot ulcers, and 15 traumatic and 221 surgical wounds) were treated for a maximum of 8 weeks with the portable NPWT device. The majority of patients (228 out of 326; 68%) achieved complete wound closure within 8 weeks of treatment. The Kaplan-Meier estimate of median time to healing of all wounds was 9 weeks. The majority of patients (318 patients, 97%) reported they were pleased or satisfied with the dressing performance. Nurses indicated satisfaction with the dressing performance for all but two patients (99%). The majority (89%) of patients managed with conventional NPWT (n=539) had an open surgical wound with moderate or high levels of exudate. Healing rates in the portable and conventional NPWT group were similar (10% to 11% per week). Portable, single-use NPWT has the potential to deliver good wound outcomes in community care settings and simplify the use of negative pressure for nurses and patients. Additional research is

  17. Intermittency in e+e- and lepton-hadron collisions

    International Nuclear Information System (INIS)

    Sugano, K.

    1990-01-01

    The intermittency data in e + e - and lepton-hadron collisions are reviewed. The power-law behavior of the moments has been established by various e + e - experiments and a μp experiment. The intermittency in the two-dimensional space of rapidity and azimuthal angle is much stronger than in the rapidity space only. The neutrino-nucleus data indicate significant effects from nuclear reinteractions. The LUND parton shower model fits the data better than the matrix element model without special retuning. The relations among the moments of different orders are in good agreement with the predictions by the negative binomial and pure birth distributions. The origin of the intermittency in e + e - and μp collisions is consistent with the self-similar cascade mechanism of jet formation. 11 refs., 7 figs

  18. Management of the open abdomen using negative pressure wound therapy with instillation in severe abdominal sepsis: A review of 48 cases in Hospital Mexico, Costa Rica.

    Science.gov (United States)

    Sibaja, Pablo; Sanchez, Alfredo; Villegas, Guillermo; Apestegui, Alvaro; Mora, Esteban

    2017-01-01

    Despite the numerous advances in recent years, severe abdominal sepsis (with associated organ failure associated with infection) remains a serious, life-threatening condition with a high mortality rate. OA is a viable alternative to the previously used scheduled repeat laparotomy or continuous peritoneal lavage. The use of Negative Pressure Wound Therapy (NPWT) has been described as a successful method of management of the open abdomen. Adding instillation of saline solution to NPWT in a programmed and controlled manner, could offer the clinician an additional tool for the management of complex septic abdomen. To explore if the concept of active two-way therapy (Negative pressure wound therapy with instillation or NPWT-I) yields superior control of underlying, life-threatening abdominal infections and its effects on survival and morbidity in patients with severe abdominal sepsis when management with an open abdomen is required. A retrospective review of 48 patients with severe abdominal sepsis, who were managed with and open abdomen and NPWT-I was performed. NPWT-I was initiated utilizing the same parameters on all patients, this consisted of cycles of instillation of saline solution, which was removed through negative pressure after a short dwell period. We observed the effects on primary fascia closure rate, mortality, hospital and SICU length of stay and associated complications. Our patient group consisted of 20 (42%) males and 28 (58%) females. Average age was 48 years. Mortality in these patients was attributed to pulmonary embolism (n=1), acute renal failure (n=2) and cardiopulmonary arrest (n=1). Average total hospital stay was 24days, and stay in the SICU (n=26) averaged 7.5days. No acute complications related to the NPWT-I. All patients presenting with abdominal compartment syndrome resolved after initiation of the NPWT-I. A total of 46 patients (96%) patients achieved fascia closure after NPWT-I therapy after an average of 6days. Four patients (8%) died

  19. High and low negative pressure suction techniques in EUS-guided fine-needle tissue acquisition by using 25-gauge needles: a multicenter, prospective, randomized, controlled trial.

    Science.gov (United States)

    Kudo, Taiki; Kawakami, Hiroshi; Hayashi, Tsuyoshi; Yasuda, Ichiro; Mukai, Tsuyoshi; Inoue, Hiroyuki; Katanuma, Akio; Kawakubo, Kazumichi; Ishiwatari, Hirotoshi; Doi, Shinpei; Yamada, Reiko; Maguchi, Hiroyuki; Isayama, Hiroyuki; Mitsuhashi, Tomoko; Sakamoto, Naoya

    2014-12-01

    EUS-guided FNA (EUS-FNA) has a high diagnostic accuracy for pancreatic diseases. However, although most reports have typically focused on cytology, histological tissue quality has rarely been investigated. The effectiveness of EUS-FNA combined with high negative pressure (HNP) suction was recently indicated for tissue acquisition, but has not thus far been tested in a prospective, randomized clinical trial. To evaluate the adequacy of EUS-FNA with HNP for the histological diagnosis of pancreatic lesions by using 25-gauge needles. Prospective, single-blind, randomized, controlled crossover trial. Seven tertiary referral centers. Patients referred for EUS-FNA of pancreatic solid lesions. From July 2011 to April 2012, 90 patients underwent EUS-FNA of pancreatic solid masses by using normal negative pressure (NNP) and HNP with 2 respective passes. The order of the passes was randomized, and the sample adequacy, quality, and histology were evaluated by a single expert pathologist. EUS-FNA by using NNP and HNP. The adequacy of tissue acquisition and the accuracy of histological diagnoses made by using the EUS-FNA technique with HNP. We found that 72.2% (65/90) and 90% (81/90) of the specimens obtained using NNP and HNP, respectively, were adequate for histological diagnosis (P = .0003, McNemar test). For 73.3% (66/90) and 82.2% (74/90) of the specimens obtained by using NNP and HNP, respectively, an accurate diagnosis was achieved (P = .06, McNemar test). Pancreatitis developed in 1 patient after this procedure, which subsided with conservative therapy. This was a single-blinded, crossover study. Biopsy procedures that combine the EUS-FNA with HNP techniques are superior to EUS-FNA with NNP procedures for tissue acquisition. ( UMIN000005939.). Copyright © 2014 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  20. Sprint cycling training improves intermittent run performance

    Directory of Open Access Journals (Sweden)

    Hardaway Chun-Kwan Chan

    2018-01-01

    Conclusions: Sprint cycling significantly improved intermittent run performance, VO2max and peak power output at VO2max. Sprint cycling training is suitable for intermittent sports athletes but separate speed and COD training should be included.

  1. Foliar δ13C Showed No Altitudinal Trend in an Arid Region and Atmospheric Pressure Exerted a Negative Effect on Plant δ13C.

    Science.gov (United States)

    Chen, Zixun; Wang, Guoan; Jia, Yufu

    2017-01-01

    Previous studies have suggested foliar δ 13 C generally increases with altitude. However, some observations reported no changes or even decreased trends in foliar δ 13 C. We noted that all the studies in which δ 13 C increased with elevation were conducted in the human regions, whereas those investigations in which δ 13 C did not vary or decreased were conducted in areas with water stress. Thus, we proposed that the pattern of increasing δ 13 C with elevation is not a general one, and that δ 13 C may remain unchanged or decrease in plants grown in arid environments. To test the hypothesis, we sampled plants along altitude gradients on the shady and sunny slopes of Mount Tianshan characterized by arid and semiarid climates. The measurements of foliar δ 13 C showed no altitudinal trends for the plants grown on either of the slopes. Therefore, this study supported our hypothesis. In addition, the present study addressed the effect of atmospheric pressure on plant δ 13 C by accounting for the effects of temperature and precipitation on δ 13 C. This study found that the residual foliar δ 13 C increased with increasing altitude, suggesting that atmospheric pressure played a negative role in foliar δ 13 C.

  2. Intermittent control of coexisting attractors.

    Science.gov (United States)

    Liu, Yang; Wiercigroch, Marian; Ing, James; Pavlovskaia, Ekaterina

    2013-06-28

    This paper proposes a new control method applicable for a class of non-autonomous dynamical systems that naturally exhibit coexisting attractors. The central idea is based on knowledge of a system's basins of attraction, with control actions being applied intermittently in the time domain when the actual trajectory satisfies a proximity constraint with regards to the desired trajectory. This intermittent control uses an impulsive force to perturb one of the system attractors in order to switch the system response onto another attractor. This is carried out by bringing the perturbed state into the desired basin of attraction. The method has been applied to control both smooth and non-smooth systems, with the Duffing and impact oscillators used as examples. The strength of the intermittent control force is also considered, and a constrained intermittent control law is introduced to investigate the effect of limited control force on the efficiency of the controller. It is shown that increasing the duration of the control action and/or the number of control actuations allows one to successfully switch between the stable attractors using a lower control force. Numerical and experimental results are presented to demonstrate the effectiveness of the proposed method.

  3. TRANSPORT BY INTERMITTENCY IN THE BOUNDARY OF THE DIII-D TOKAMAK

    International Nuclear Information System (INIS)

    BOEDO, JA; RUDAKOV, DL; MOYER, RA; MCKEE, GR; COLCHIN, RJ; SCHAFFER, MJ; STANGEBY, PG; WEST, WP; ALLEN, SL; EVANS, TE; FONCK, RJ; HOLLMANN, EM; KRASHENINNIKOV, S; LEONARD, AW; NEVINS, W; MAHDAVI, MA; PORTER, GD; TYNAN, GR; WHYTE, DG; XU, X

    2002-01-01

    A271 TRANSPORT BY INTERMITTENCY IN THE BOUNDARY OF THE DIII-D TOKAMAK. Intermittent plasma objectives (IPOs) featuring higher pressure than the surrounding plasma, are responsible for ∼ 50% of the E x B T radial transport in the scrape off layer (SOL) of the DIII-D tokamak in L- and H-mode discharges. Conditional averaging reveals that the IPOs are positively charged and feature internal poloidal electric fields of up to 4000 V/m. The IPOs move radially with E x B T /B 2 velocities of ∼ 2600 m/s near the last closed flux surface (LCFS), and ∼ 330 m/s near the wall. The IPOs slow down as they shrink in radial size from 4 cm at the LCFS to 0.5 cm near the wall. The skewness (i.e. asymmetry of fluctuations from the average) of probe and beam emission spectroscopy (BES) data indicate IPO formation at or near the LCFS and the existence of positive and negative IPOs which move in opposite directions. The particle content of the IPOs at the LCFS is linearly dependent on the local density and decays over ∼ 3 cm into the SOL while their temperature decays much faster (∼ 1 cm)

  4. Towards an intermittency-friendly energy system

    DEFF Research Database (Denmark)

    Blarke, Morten

    2012-01-01

    are capitulating as wind power penetration levels are moving above 25%; some operators are retiring cogeneration units entirely, while other operators are making way for heat-only boilers. This development is jeopardizing the system-wide energy, economic, and environmental benefits that distributed cogeneration...... still has to offer. The solution is for distributed operators to adapt their technology and operational strategies to achieve a better co-existence between cogeneration and wind power. Four options for doing so are analysed including a new concept that integrates a high pressure compression heat pump......Distributed cogeneration has played a key role in the implementation of sustainable energy policies for three decades. However, increasing penetration levels of intermittent renewables is challenging that position. The paradigmatic case of West Denmark indicates that distributed operators...

  5. Incisional Negative Pressure Wound Therapy

    DEFF Research Database (Denmark)

    Hyldig, Nana; Vinter, Christina Anne; Bille, Camilla

    generator are used to allocate the participants into one of two groups (iNPWT vs. standard dressing), stratified by centre and type of CS. The study is conducted at five public hospitals located in three regions of Denmark. Interim analyses will be preformed along the trial using the group sequential method...... Therapy (iNPWT) applied prophylactically following caesarean section compared with standard postoperative dressings in obese women undergoing caesarean section. Method: This study is designed as an unblinded, pragmatic, parallel randomised multicenter trial, with a 1:1 allocation. A computer random number...

  6. Effects of Intermittent Fasting, Caloric Restriction, and Ramadan Intermittent Fasting on Cognitive Performance at Rest and During Exercise in Adults.

    Science.gov (United States)

    Cherif, Anissa; Roelands, Bart; Meeusen, Romain; Chamari, Karim

    2016-01-01

    The aim of this review was to highlight the potent effects of intermittent fasting on the cognitive performance of athletes at rest and during exercise. Exercise interacts with dietary factors and has a positive effect on brain functioning. Furthermore, physical activity and exercise can favorably influence brain plasticity. Mounting evidence indicates that exercise, in combination with diet, affects the management of energy metabolism and synaptic plasticity by affecting molecular mechanisms through brain-derived neurotrophic factor, an essential neurotrophin that acts at the interface of metabolism and plasticity. The literature has also shown that certain aspects of physical performance and mental health, such as coping and decision-making strategies, can be negatively affected by daylight fasting. However, there are several types of intermittent fasting. These include caloric restriction, which is distinct from fasting and allows subjects to drink water ad libitum while consuming a very low-calorie food intake. Another type is Ramadan intermittent fasting, which is a religious practice of Islam, where healthy adult Muslims do not eat or drink during daylight hours for 1 month. Other religious practices in Islam (Sunna) also encourage Muslims to practice intermittent fasting outside the month of Ramadan. Several cross-sectional and longitudinal studies have shown that intermittent fasting has crucial effects on physical and intellectual performance by affecting various aspects of bodily physiology and biochemistry that could be important for athletic success. Moreover, recent findings revealed that immunological variables are also involved in cognitive functioning and that intermittent fasting might impact the relationship between cytokine expression in the brain and cognitive deficits, including memory deficits.

  7. Fluid Redistribution and Heart Rate in Humans During Whole-Body Tilting, G(z) Centrifugation, and Lower Body Negative Pressure

    Science.gov (United States)

    Watenpaugh, D. E.; Breit, G. A.; Ballard, R. E.; Murthy, G.; Hargens, A. R.

    1994-01-01

    Gravity creates blood pressure gradients which redistribute body fluids towards the feet. Positive G(z) centrifugation and lower body negative pressure (LBNP) have been proposed to simulate these and other effects of gravity during long-term existence in microgravity. We hypothesized that the magnitude of upper-to-lower body fluid redistribution would increase according to the following order: short-arm centrifugation (SAC), long-arm centrifugation (LAC), head-up tilt (HUT), and LBNP. To test this hypothesis, we employed strain gauge plethysmography of the neck, thigh and calf during HUT and supine SAC and LAC up to lG(z) at the feet, and during supine LBNP to 100 mm Hg. Supine 100 mm Hg LBNP generates footward force and produces transmural blood pressures in the foot approximately equal to 1 G(z) (90 deg) HUT. Heart rate was measured via cardiotachometry. Control measurements were made while supine. SAC and LAC elicited similar increases in thigh volume at 1 G(z) (2.3 +/- 0.4 and 2.1 +/- 0.1%, respectively; mean +/- se, n greater than or equal to 7). At 100 mm Hg LBNP, thigh volume increased (3.4 +/- 0.3%) significantly more than during l G(z) centrifugation (p less than 0.05). Surprisingly, due to a paradoxical 0.6% reduction of thigh volume between 0.8 and 1.0 G(z) HUT, thigh volume was increased only 0.6 +/- 0.3% at 1 G(z) HUT. The calf demonstrated similar, although less definitive, responses to the various gravitational stimuli. Neck volume tended to decrease less during HUT than during the other stimuli. Heart rate increased similarly during HUT (18 +/- 2 beats/min) and LAC (12 +/- 2 beats/min), and exhibited still greater elevation during LBNP (29 +/- 4 beats/min), yet did not increase during SAC. These results suggest upright posture activates mechanisms that counteract footward fluid redistribution which are not activated during supine applications of simulated gravity. LAC more closely approximated effects of normal gravity (HUT) than LBNP. Therefore

  8. Negative Pressure Wound Therapy Literature Review of Efficacy, Cost Effectiveness, and Impact on Patients' Quality of Life in Chronic Wound Management and Its Implementation in the United Kingdom

    Directory of Open Access Journals (Sweden)

    Diaa Othman

    2012-01-01

    Full Text Available This is a paper reviewing the National Health Service (NHS agenda in relation to the use of Negative Pressure Wound Therapy (NPWT in chronic wound management and assesses the evidence behind it, its cost effectiveness and the outcome it has on patients’ satisfaction and life style. Multiple studies over the last 10 years looking at clinical efficacy of NPWT with its cost effectiveness and the implementation of this service in the UK were reviewed. NPWT has showed a reasonable body of evidence to support its usage in chronic wounds with potential positive outcomes on finance and patients’ satisfaction. However, the NHS system shows significant variations in the availability and implementation of this useful tool, depending on care providers and resources availabilities. The paper concluded that the NPWT can be a useful source of cutting down costs of chronic wound managements and saving money by its effect on expediting wound healing, which can address a part of the financial crises facing the NHS, however, has to be considered according to specific case needs. There should also be a national standard for the availability and indication of this tool to assure equal opportunities for different patients in different areas in the country.

  9. Silver from polyurethane dressing is delivered by gradient to exudate, tissue, and serum of patients undergoing negative-pressure wound treatment.

    Science.gov (United States)

    Abarca-Buis, René F; Munguía, Nadia M; Gonzalez, Juan Manuel Melchor; Solís-Arrieta, Lilia; y Osorio, Liliana Saldivar; Krötzsch, Edgar

    2014-04-01

    This study aimed to evaluate the distribution and concentration of silver eluted from silver-coated polyurethane dressing (V.A.C. GranuFoam Silver Dressing; KCI, San Antonio, Texas) in vitro and in patients undergoing negative-pressure wound therapy (NPWT). This was a descriptive study of the effect of silver-coated polyurethane dressing in patients undergoing NPWT. Six patients with infected wounds undergoing NPWT using silver-coated polyurethane dressing. To evaluate silver release in vitro, the authors soaked dressing fragments in water and human serum for different lengths of time and performed atomic absorption spectroscopy. For patient evaluation, the authors obtained exudate, serum, and wound tissue at different time points from 6 patients undergoing NPWT and measured silver levels by atomic absorption and dispersed x-ray spectroscopy. Silver from the dressing was immediately released in vitro at a rate 3 times greater in serum than in water. In vivo, silver was delivered to wound exudate at rates 102 to 104 times greater than in corresponding serum. Few surface silver deposits were detected in treated tissue. The high concentration of silver found in wound exudate reflects not only the affinity for silver in serum components and wound fluids, but also that most silver ions are not distributed systemically in the patient; instead, they are transported by the vacuum created by therapy.

  10. Laparostomy management using the ABThera™ open abdomen negative pressure therapy system in a grade IV open abdomen secondary to acute pancreatitis.

    Science.gov (United States)

    Fitzgerald, James E F; Gupta, Shradha; Masterson, Sarah; Sigurdsson, Helgi H

    2013-04-01

    Wound control in laparostomy for the treatment of intra-abdominal hypertension remains challenging and numerous techniques have been described. We report the first UK experience with a new commercially available device specifically designed to facilitate management of the open abdomen. A 44-year-old gentleman presented with a 3-day history of constant severe epigastric pain and associated vomiting. Amylase was markedly elevated and he was admitted for supportive management of pancreatitis, with subsequent transfer to intensive care due to severe systemic inflammatory syndrome. The patient decompensated, developing intra-abdominal hypertension with renal and respiratory failure. This was successfully managed by performing a laparostomy and using an ABThera™ Open Abdomen Negative Pressure Therapy System (KCI, San Antonio, TX). We describe its use to facilitate wound control, including enteroatmospheric fistula, allowing granulation and eventual restoration of gastrointestinal continuity 383-days after admission. We found the ABThera™ System proved to be a useful treatment adjunct, protecting intra-abdominal contents while removing large volumes of exudate and infected material from within the abdominal cavity. Complex cases such as this remain infrequent and this article provides a summary of our experience, including a review of indications for laparostomy and the underlying basic science in this difficult area. © 2012 The Authors. International Wound Journal © 2012 Blackwell Publishing Ltd and Medicalhelplines.com Inc.

  11. Ultra pressure liquid chromatography-negative electrospray ionization mass spectrometry determination of twelve halobenzoquinones at ng/L levels in drinking water.

    Science.gov (United States)

    Huang, Rongfu; Wang, Wei; Qian, Yichao; Boyd, Jessica M; Zhao, Yuli; Li, Xing-Fang

    2013-05-07

    We report here the characterization of twelve halobenzoquinones (HBQs) using electrospray ionization (ESI) high resolution quadrupole time-of-flight mass spectrometry. The high resolution negative ESI spectra of the twelve HBQs formed two parent ions, [M + H(+) + 2e(-)], and the radical M(-•). The intensities of these two parent ions are dependent on their chemical structures and on instrumental parameters such as the source temperature and flow rate. The characteristic ions of the HBQs were used to develop an ultra pressure liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. At the UPLC flow rate (400 μL/min) and under the optimized ESI conditions, eleven HBQs showed the stable and abundant transitions [M + H(+) + 2e(-)] → X(-) (X(-) representing Cl(-), Br(-), or I(-)), while dibromo-dimethyl-benzoquinone (DBDMBQ) showed only the transition of M(-•) → Br(-). The UPLC efficiently separates all HBQs including some HBQ isomers, while the MS/MS offers exquisite limits of detection (LODs) at subng/mL levels for all HBQs except DBDMBQ. Combined with solid phase extraction (SPE), the method LOD is down to ng/L. The results from analysis of authentic samples demonstrated that the SPE-UPLC-MS/MS method is reliable, fast, and sensitive for the identification and quantification of the twelve HBQs in drinking water.

  12. Negative pressure wound therapy literature review of efficacy, cost effectiveness, and impact on patients' quality of life in chronic wound management and its implementation in the United kingdom.

    Science.gov (United States)

    Othman, Diaa

    2012-01-01

    This is a paper reviewing the National Health Service (NHS) agenda in relation to the use of Negative Pressure Wound Therapy (NPWT) in chronic wound management and assesses the evidence behind it, its cost effectiveness and the outcome it has on patients' satisfaction and life style. Multiple studies over the last 10 years looking at clinical efficacy of NPWT with its cost effectiveness and the implementation of this service in the UK were reviewed. NPWT has showed a reasonable body of evidence to support its usage in chronic wounds with potential positive outcomes on finance and patients' satisfaction. However, the NHS system shows significant variations in the availability and implementation of this useful tool, depending on care providers and resources availabilities. The paper concluded that the NPWT can be a useful source of cutting down costs of chronic wound managements and saving money by its effect on expediting wound healing, which can address a part of the financial crises facing the NHS, however, has to be considered according to specific case needs. There should also be a national standard for the availability and indication of this tool to assure equal opportunities for different patients in different areas in the country.

  13. The Effect of Negative Pressure Wound Therapy With Antiseptic Instillation on Biofilm Formation in a Porcine Model of Infected Spinal Instrumentation.

    Science.gov (United States)

    Singh, Devinder P; Gowda, Arvind U; Chopra, Karan; Tholen, Michael; Chang, Sarah; Mavrophilipos, Vasilios; Semsarzadeh, Nina; Rasko, Yvonne; Holton Iii, Luther

    2017-06-01

    This study evaluates the effect of negative pressure wound therapy with antiseptic instillation (NPWTi) in the clearance of infection and biofilm formation in an in vivo model of infected spinal implants compared to traditional treatment modalities. Five pigs underwent titanium rod implantation of their spinous processes followed by injection of 1 x 106 CFUs/100μL of methicillin-resistant Staphylococcus aureus through the fascia at each site. At 1 week postoperatively, an experimental arm of 3 pigs received NPWTi, and a control arm of 2 pigs received wet-to-dry dressings. The persistence of local infection in the experimental group was compared to the control group using tissue cultures. Biofilm development on spinal implants was evaluated using scanning electron microscopy. Mean bacterial count showed a statistical difference between the experimental and the control groups (P < .05). Scanning electron microscopy revealed the presence of uniform biofilm formation across the surface of control group instrumentation, whereas the experimental group showed interrupted areas between biofilm formations. The authors concluded that NPWTi is associated with decreased bacterial load and biofilm formation compared to wet-to-dry dressings in an in vivo porcine model of infected spinal instrumentation.

  14. Combined use of fenestrated-type artificial dermis and topical negative pressure wound therapy for the venous leg ulcer of a rheumatoid arthritis patient.

    Science.gov (United States)

    Morimoto, Naoki; Kuro, Atsuyuki; Yamauchi, Takashi; Horiuchi, Ai; Kakudo, Natsuko; Sakamoto, Michiharu; Suzuki, Kenji; Kusumoto, Kenji

    2016-02-01

    We report a case of circumferential venous leg ulcer in a rheumatoid arthritis patient. Mesh skin grafting was performed in another hospital, but the graft failed and the patient was referred to our hospital. This ulcer was treated by the combination therapy of a fenestrated-type artificial dermis with negative pressure wound therapy (NPWT) and secondary mesh grafting using our 'grip tape technique'. NPWT was started at -100 mmHg and continued until the formation of dermis-like tissue. A section stained using haematoxylin and eosin and an anti-αSMA (α smooth muscle actin) immunohistological section of the biopsy from dermis-like tissue showed an abundant infiltration of fibroblasts and capillary formation beneath the fenestration of the silicone sheet. Threefold mesh skin grafting was subsequently performed and it was taken up completely. The fenestrated-type artificial dermis in combination with NPWT produced good results without infection in the treatment of complex wounds. In addition, our 'grip tape technique' was useful to apply polyurethane foam to the entire surface of the lower leg. © 2015 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  15. Negative Pressure Wound Therapy Literature Review of Efficacy, Cost Effectiveness, and Impact on Patients' Quality of Life in Chronic Wound Management and Its Implementation in the United Kingdom

    Science.gov (United States)

    Othman, Diaa

    2012-01-01

    This is a paper reviewing the National Health Service (NHS) agenda in relation to the use of Negative Pressure Wound Therapy (NPWT) in chronic wound management and assesses the evidence behind it, its cost effectiveness and the outcome it has on patients' satisfaction and life style. Multiple studies over the last 10 years looking at clinical efficacy of NPWT with its cost effectiveness and the implementation of this service in the UK were reviewed. NPWT has showed a reasonable body of evidence to support its usage in chronic wounds with potential positive outcomes on finance and patients' satisfaction. However, the NHS system shows significant variations in the availability and implementation of this useful tool, depending on care providers and resources availabilities. The paper concluded that the NPWT can be a useful source of cutting down costs of chronic wound managements and saving money by its effect on expediting wound healing, which can address a part of the financial crises facing the NHS, however, has to be considered according to specific case needs. There should also be a national standard for the availability and indication of this tool to assure equal opportunities for different patients in different areas in the country. PMID:22701169

  16. Negative pressure wound therapy using a portable single-use device for free skin grafts on the distal extremity in seven dogs.

    Science.gov (United States)

    Miller, A J; Cashmore, R G; Marchevsky, A M; Havlicek, M; Brown, P M; Fearnside, S M

    2016-09-01

    Retrospective study to describe clinical experience with a portable single-use negative pressure wound therapy device after application of full-thickness meshed skin grafts to wounds on the distal extremities of seven dogs. Seven dogs were treated with portable NPWT after receiving skin grafts; six as the result of tumour resection and one for traumatic injury. Medical records were reviewed and data recorded on patient signalment, cause and location of wound, surgical technique, application and maintenance of portable NPWT, graft survival and outcome, and complications encountered with the system. NPWT was provided for between 4 and 7 days. Five patients were discharged from hospital during the treatment period. Application and maintenance of the portable device was technically easy and no major complications were encountered. Minor complications consisted of fluid accumulation in the evacuation tubing. All dogs achieved 100% graft survival. Application and maintenance of the portable device was technically straightforward. All dogs receiving portable NPWT after transfer of a free skin graft to the distal extremity had a successful outcome. © 2016 Australian Veterinary Association.

  17. Negative pressure wound therapy, silver coated foam dressing and conventional bandages in open wound treatment in dogs. A retrospective comparison of 50 paired cases.

    Science.gov (United States)

    Nolff, M C; Fehr, M; Bolling, A; Dening, R; Kramer, S; Reese, S; Meyer-Lindenberg, A

    2015-01-01

    To evaluate negative pressure wound therapy (NPWT) for treatment of complicated wounds in dogs. Retrospective multicentre study. Dogs (n = 50) undergoing open wound treatment were classified according to treatment method used: bandage (Group A, n = 7), NPWT (Group B, n = 18), and foam dressing (Group C, n = 25). Pairs of patients matched based on wound conformation, localization, and underlying cause were compared between Group A and C (n = 7 pairs) and between groups B and C (n = 18 pairs) in terms of duration of previous treatment, time to closure, and complications. Signalment, antibiotic medications, antiseptic treatment, and bacterial status of wounds were comparable between groups. The duration of previous treatment was significantly higher in patients assigned to Group B (p = 0.04) compared to Group C, while no significant difference was found between groups A and B. Total time to wound closure was significantly shorter in Group C compared to Group A (p = 0.02) and in Group B compared to Group C (p = 0.003). Wounds treated with NPWT suffered significantly less complications (p = 0.008) and were significantly less septic during treatment (p = 0.016) than wounds treated with a foam dressing. This study shows that time to healing was halved in NPWT treated patients compared to foam dressing treated patients, which in turn healed faster than patients treated with conventional bandage, underlining the value of NPWT therapy for the treatment of complicated wounds.

  18. Clinical Experience With the Use of Negative Pressure Wound Therapy Combined With a Silver-impregnated Dressing in Mixed Wounds: A Retrospective Study of 50 Cases.

    Science.gov (United States)

    Bukovcan, Peter; Koller, Jan; Hajská, Marianna; Záhorec, Peter

    2016-08-01

    Although negative pressure wound therapy (NPWT) has been used for more than 20 years, as far as the authors are aware, there is little research aimed at the evaluation of the combination of NPWT with a silver-impregnated dressing. The aim of this study was to examine the effect, efficacy, and safety of NPWT in conjunction with a silver-impregnated dressing. The authors used a retrospective study of 54 acute and chronic wounds treated in 50 patients over a 2-year period. Demographic data, wound characterizations, wound cultures before and after NPWT, the duration of NPWT and number of sponge changes for each patient, the types of surgical procedures used for wound closure following NPWT, and the healing time and length of hospital stays were recorded. In 26 wounds, deep structures (ie, bones and tendons) were exposed. The mean NPWT duration was 9.2 days. Mean healing time was 16 days. There was a statistically significant decrease in the pathogenic microbial strains after NPWT treatment combined with the silver-impregnated dressing (paired t test; P = 0.0038). The shift from complicated to easier surgical wound-closure procedures was observed. According to all results obtained, described, and discussed, the authors consider the use of a nonadherent silver-impregnated dressing in conjunction with NPWT to be beneficial and efficacious. No adverse events or reactions related to the silver-impregnated contact layer used during NPWT have been observed in the patients, which confirmed the safety of this method.

  19. Negative pressure wound therapy applied before and after split-thickness skin graft helps healing of Fournier gangrene: a case report (CARE-Compliant).

    Science.gov (United States)

    Ye, Junna; Xie, Ting; Wu, Minjie; Ni, Pengwen; Lu, Shuliang

    2015-02-01

    Fournier gangrene is a rare but highly infectious disease characterized by fulminant necrotizing fasciitis involving the genital and perineal regions. Negative pressure wound therapy (NPWT; KCI USA Inc, San Antonio, TX) is a widely adopted technique in many clinical settings. Nevertheless, its application and effect in the treatment of Fournier gangrene are unclear. A 47-year-old male patient was admitted with an anal abscess followed by a spread of the infection to the scrotum, which was caused by Pseudomonas aeruginosa. NPWT was applied on the surface of the scrotal area and continued for 10 days. A split-thickness skin graft from the scalp was then grafted to the wound, after which, NPWT utilizing gauze sealed with an occlusive dressing and connected to a wall suction was employed for 7 days to secure the skin graft. At discharge, the percentage of the grafted skin alive on the scrotum was 98%. The wound beside the anus had decreased to 4 × 0.5 cm with a depth of 1 cm. Follow-up at the clinic 1 month later showed that both wounds had healed. The patient did not complain of any pain or bleeding, and was satisfied with the outcome. NPWT before and after split-thickness skin grafts is safe, well tolerated, and efficacious in the treatment of Fournier gangrene.

  20. Quality of plant-based food materials and its prediction during intermittent drying.

    Science.gov (United States)

    Duc Pham, Nghia; Khan, Md Imran H; Joardder, M U H; Rahman, M M; Mahiuddin, Md; Abesinghe, A M Nishani; Karim, M A

    2017-11-30

    In most drying processes, several physical, chemical and nutritional modifications take place in food products. Innovative drying techniques such as intermittent drying can enhance the quality of dehydrated products effectively and efficiently. Intermittent drying is a technique where drying conditions are changed through varying the drying air temperature, humidity, velocity, pressure, or even mode of heat input. This drying technique has been successfully applied to overcome the problems of conventional drying systems such as longer time consumption, case hardening, lower energy efficiency and poor-quality attributes. However, as the effect of intermittent drying on food quality is not yet well understood, a comprehensive study of quality change during intermittent drying is crucial. The main aim of this paper is to present a thorough review of the potential effect of intermittent drying methods on physical, chemical, nutritional, and stability characteristics of plant-based food material. It is found that application of intermittency using different drying systems has a significant effect on product quality and its stability. In addition, a comprehensive review on existing models of physio/biochemical kinetics for food drying is presented. Finally, the paper is concluded with the discussion of the current challenges and future directions of intermittent drying for producing high-quality dried food products.

  1. Emotion regulation deficits in intermittent explosive disorder.

    Science.gov (United States)

    Fettich, Karla C; McCloskey, Michael S; Look, Amy E; Coccaro, Emil F

    2015-01-01

    Intermittent explosive disorder (IED) is a psychiatric disorder characterized by repeated acts of affective aggression. Despite the diagnostic emphasis on the failure to control aggressive impulses, there is little research on affective processes and emotion regulation in IED; however, this research suggests possible dysfunctions in experiences of emotional intensity and lability. The hypothesis in the present study was that compared to individuals with other psychiatric disorders, and psychologically healthy individuals, individuals with IED experience greater negative affect intensity and emotional lability. Participants (N = 373) consisted of 202 individuals diagnosed with IED, 68 non-IED psychiatric controls (PC), and 103 healthy volunteers (HV). Emotion regulation was assessed using the General Behavior Inventory, the Affective Lability Scale, and the Affect Intensity Measure. Results showed that IED participants reported greater negative affect intensity and greater emotional lability across several emotion domains (e.g., anger, anxiety, depression) than PC and HV participants. These findings suggest that IED is characterized by more global emotion regulation deficits than those associated with anger alone. Aggr. Behav. 41:25-33 2015. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  2. Empirical heuristics for improving Intermittent Demand Forecasting

    OpenAIRE

    Petropoulos, Fotios; Nikolopoulos, Konstantinos; Spithourakis, George; Assimakopoulos, Vassilios

    2013-01-01

    Purpose– Intermittent demand appears sporadically, with some time periods not even displaying any demand at all. Even so, such patterns constitute considerable proportions of the total stock in many industrial settings. Forecasting intermittent demand is a rather difficult task but of critical importance for corresponding cost savings. The current study aims to examine the empirical outcomes of three heuristics towards the modification of established intermittent demand forecasting approaches...

  3. Evidence-based recommendations for the use of Negative Pressure Wound Therapy in traumatic wounds and reconstructive surgery: steps towards an international consensus.

    Science.gov (United States)

    Krug, E; Berg, L; Lee, C; Hudson, D; Birke-Sorensen, H; Depoorter, M; Dunn, R; Jeffery, S; Duteille, F; Bruhin, A; Caravaggi, C; Chariker, M; Dowsett, C; Ferreira, F; Martínez, J M Francos; Grudzien, G; Ichioka, S; Ingemansson, R; Malmsjo, M; Rome, P; Vig, S; Runkel, N; Martin, R; Smith, J

    2011-02-01

    Negative pressure wound therapy (NPWT) has become widely adopted over the last 15 years and over 1000 peer reviewed publications are available describing its use. Despite this, there remains uncertainty regarding several aspects of usage. In order to respond to this gap a global expert panel was convened to develop evidence-based recommendations describing the use of NPWT. In this paper the results of the study of evidence in traumatic wounds (including soft tissue defects, open fractures and burns) and reconstructive procedures (including flaps and grafts) are reported. Evidence-based recommendations were obtained by a systematic review of the literature, grading of evidence, drafting of the recommendations by a global expert panel, followed by a formal consultative consensus development program in which 422 independent healthcare professionals were able to agree or disagree with the recommendations. The criteria for agreement were set at 80% approval. Evidence and recommendations were graded according to the SIGN (Scottish Intercollegiate Guidelines Network) classification system. Twelve recommendations were developed in total; 4 for soft tissue trauma and open fracture injuries, 1 for burn injuries, 3 for flaps and 4 for skin grafts. The present evidence base is strongest for the use of NPWT on skin grafts and weakest as a primary treatment for burns. In the consultative process, 11/12 of the proposed recommendations reached the 80% agreement threshold. The development of evidence-based recommendations for NPWT with direct validation from a large group of practicing clinicians offers a broader basis for consensus than work by an expert panel alone. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Does treatment of split-thickness skin grafts with negative-pressure wound therapy improve tissue markers of wound healing in a porcine experimental model?

    Science.gov (United States)

    Ward, Christopher; Ciraulo, David; Coulter, Michael; Desjardins, Steven; Liaw, Lucy; Peterson, Sarah

    2012-08-01

    Negative-pressure wound therapy (NPWT) has been used for to treat wounds for more than 15 years and, more recently, has been used to secure split-thickness skin grafts. There are some data to support this use of NPWT, but the actual mechanism by which NPWT speeds healing or improves skin graft take is not entirely known. The purpose of this project was to assess whether NPWT improved angiogenesis, wound healing, or graft survival when compared with traditional bolster dressings securing split-thickness skin grafts in a porcine model. We performed two split-thickness skin grafts on each of eight 30 kg Yorkshire pigs. We took graft biopsies on postoperative days 2, 4, 6, 8, and 10 and submitted the samples for immunohistochemical staining, as well as standard hematoxylin and eosin staining. We measured the degree of vascular ingrowth via immunohistochemical staining for von Willenbrand's factor to better identify blood vessel epithelium. We determined the mean cross-sectional area of blood vessels present for each representative specimen, and then compared the bolster and NPWT samples. We also assessed each graft for incorporation and survival at postoperative day 10. Our analysis of the data revealed that there was no statistically significant difference in the degree of vascular ingrowth as measured by mean cross-sectional capillary area (p = 0.23). We did not note any difference in graft survival or apparent incorporation on a macroscopic level, although standard hematoxylin and eosin staining indicated that microscopically, there seemed to be better subjective graft incorporation in the NPWT samples and a nonsignificant trend toward improved graft survival in the NPWT group. We were unable to demonstrate a significant difference in vessel ingrowth when comparing NPWT and traditional bolster methods for split-thickness skin graft fixation. More studies are needed to elucidate the manner by which NPWT exerts its effects and the true clinical magnitude of these

  5. Comparison of Negative Pressure Wound Therapy Using Vacuum-Assisted Closure with Advanced Moist Wound Therapy in the Treatment of Diabetic Foot Ulcers.

    Science.gov (United States)

    Sajid, Muhammad Tanveer; Mustafa, Qurat ul Ain; Shaheen, Neelofar; Hussain, Syed Mukarram; Shukr, Irfan; Ahmed, Muhammad

    2015-11-01

    To evaluate the clinical efficacy of Negative Pressure Wound Therapy (NPWT) using Vacuum Assisted Closure (VAC) compared with Advanced Moist Wound Therapy (AMWT) to treat Diabetic Foot Ulcer (DFU). Randomized control trial. Surgical Department, Combined Military Hospital (CMH) / Military Hospital (MH), Rawalpindi, from November 2010 to June 2012. The study consisted of 278 patients, with 139 patients each in Group 'A' and 'B', who were subjected to AMWT and NPWT, respectively. Wound was assessed digitally every week for 2 weeks. Wound dimension and surface area were determined using University of Texas Health Centre at San Antonio (UTHCSA) image tool version 3.0. Efficacies of AMWT and NPWT were compared in terms of reduction in wound area over 2 weeks. Mean age of presentation in group A was 55.88 ± 10.97 years while in group B, it was 56.83 ± 11.3 (p=0.48). Mean duration of diabetes at presentation was 15.65 ± 4.86 and 15.96 ± 5.79 years in group A and B, respectively (p=0.74). Majority of patients had Wagner's grade 2 ulcer (82% in group A and 87.8% in group B, p= 0.18). Initial wound size in group A was 15.07 ± 2.92 cm2 and in group B 15.09 ± 2.81 cm2 (p = 0.95). Wound size measured after 2 weeks, treatment was in group A13.70 ± 2.92 cm2 and in group B 11.53 ± 2.78 cm2 (p VAC was more efficacious than AMWT in the management of diabetic foot ulcers.

  6. Comparison of negative pressure wound therapy using vacuum-assisted closure with advanced moist wound therapy in the treatment of diabetic foot ulcers

    International Nuclear Information System (INIS)

    Sajid, M.T.; Mustafa, Q.U.A.

    2015-01-01

    Objective: To evaluate the clinical efficacy of Negative Pressure Wound Therapy (NPWT) using Vacuum Assisted Closure (VAC) compared with Advanced Moist Wound Therapy (AMWT) to treat Diabetic Foot Ulcer (DFU). Study Design: Randomized control trial. Place and Duration of Study: Surgical Department, Combined Military Hospital (CMH) / Military Hospital (MH), Rawalpindi, from November 2010 to June 2012. Methodology: The study consisted of 278 patients, with 139 patients each in Group A and B, who were subjected to AMWT and NPWT, respectively. Wound was assessed digitally every week for 2 weeks. Wound dimension and surface area were determined using University of Texas Health Centre at San Antonio (UTHCSA) image tool version 3.0. Efficacies of AMWT and NPWT were compared in terms of reduction in wound area over 2 weeks. Results: Mean age of presentation in group Awas 55.88 10.97 years while in group B, it was 56.83 ± 11.3 (p=0.48). Mean duration of diabetes at presentation was 15.65 ± 4.86 and 15.96 ± 5.79 years in group A and B, respectively (p=0.74). Majority of patients had Wagner's grade 2 ulcer (82% in group A and 87.8% in group B, p= 0.18). Initial wound size in group A was 15.07 ± 2.92 cm2and in group B 15.09 ± 2.81 cm2(p = 0.95). Wound size measured after 2 weeks, treatment was in group A13.70 ± 2.92 cm2 and in group B 11.53 ± 2.78 cm2 (p < 0.001). Wound area reduction in both groups revealed statistically significant faster healing in group B as compared to group A(p < 0.001). Conclusion: NPWT using VAC was more efficacious than AMWT in the management of diabetic foot ulcers. (author)

  7. Negative Pressure Wound Therapy versus modified Barker Vacuum Pack as temporary abdominal closure technique for Open Abdomen management: a four-year experience.

    Science.gov (United States)

    Montori, Giulia; Allievi, Niccolò; Coccolini, Federico; Solaini, Leonardo; Campanati, Luca; Ceresoli, Marco; Fugazzola, Paola; Manfredi, Roberto; Magnone, Stefano; Tomasoni, Matteo; Ansaloni, Luca

    2017-07-21

    We reviewed our experience with patients presenting with trauma and peritonitis who underwent an open abdomen (OA) procedure, and compared outcomes between Negative Pressure Wound Therapy (NPWT) and a modified Barker Vacuum Pack (mBVP) technique. In this descriptive study, we retrospectively analyzed data regarding all patients who underwent OA for intra-abdominal sepsis or abdominal trauma at our Centre from January 2012 to December 2015. Demographic data, co-morbidities, indications to surgery, intra-operative details and Björck classification grade were considered. Outcomes included were: time to closure in days, fascial closure rates, ICU and hospital stay, in-hospital and overall mortality, and entero-atmospheric fistula rate. A total of 83 cases were considered. Mean closure time was 6 days versus 6.5 days (p = 0.71) in NPWT and mBVP groups, respectively; the fascial closure rate was 75.4% versus 93.8% (p = 0.10). At multivariate analysis, in-hospital and overall mortality were significantly higher within the mBVP, as compared to NPWT (OR 3.8, 95% CI 1.1 to 13.1, p = 0.02 - OR 4.2, 95% CI 1.2 to 14.1, p = 0.01). Entero-atmospheric fistula rate was 2.6% in the two groups. NPWT as a temporary abdominal closure technique, as compared to mBVP, appears to be associated with better outcomes in terms of mortality.

  8. Application of a drainage film reduces fibroblast ingrowth into large-pored polyurethane foam during negative-pressure wound therapy in an in vitro model.

    Science.gov (United States)

    Wiegand, Cornelia; Springer, Steffen; Abel, Martin; Wesarg, Falko; Ruth, Peter; Hipler, Uta-Christina

    2013-01-01

    Negative-pressure wound therapy (NPWT) is an advantageous treatment option in wound management to promote healing and reduce the risk of complications. NPWT is mainly carried out using open-cell polyurethane (PU) foams that stimulate granulation tissue formation. However, growth of wound bed tissue into foam material, leading to disruption of newly formed tissue upon dressing removal, has been observed. Consequently, it would be of clinical interest to preserve the positive effects of open-cell PU foams while avoiding cellular ingrowth. The study presented analyzed effects of NPWT using large-pored PU foam, fine-pored PU foam, and the combination of large-pored foam with drainage film on human dermal fibroblasts grown in a collagen matrix. The results showed no difference between the dressings in stimulating cellular migration during NPWT. However, when NPWT was applied using a large-pored PU foam, the fibroblasts continued to migrate into the dressing. This led to significant breaches in the cell layers upon removal of the samples after vacuum treatment. In contrast, cell migration stopped at the collagen matrix edge when fine-pored PU foam was used, as well as with the combination of PU foam and drainage film. In conclusion, placing a drainage film between collagen matrix and the large-pored PU foam dressing reduced the ingrowth of cells into the foam significantly. Moreover, positive effects on cellular migration were not affected, and the effect of the foam on tissue surface roughness in vitro was also reduced. © 2013 by the Wound Healing Society.

  9. Use of collagenase ointment in conjunction with negative pressure wound therapy in the care of diabetic wounds: a case series of six patients

    Directory of Open Access Journals (Sweden)

    John D. Miller

    2015-01-01

    Full Text Available Background: Diabetic wounds with additional comorbidities are costly, time intensive, and difficult to heal. Often, multiple modalities may be necessary to achieve wound resolution, relying on the synergistic advantage of each therapy to affect wound healing. The selectivity of Clostridium collagenase is physiologically effective at degrading non-viable collagen fibers while preserving living collagen tissue. Additionally, negative pressure wound therapy (NPWT has long been used to aid wound healing while concurrently depreciating biological wound burden time. Methods: Six patients were selected from those appearing to our university based limb salvage service. Inclusion criteria included patients with a recurrent mixed fibrotic and granular wound base, in which NPWT was indicated, without exclusion criteria. Patients enrolled were administered clostridial collagenase ointment at each regularly scheduled NPWT dressing change. Patients were followed until healing, with visual representations of wound progression and time to full healing recorded. Results: Tandem application of these therapies appeared to expedite wound healing by clearing degenerative fibrous tissue and expediting wound granulation without additional complication. Unfortunately, not all patients were able to reach full healing; with two patients experiencing ulcer recurrence, likely a result of their significant comorbid nature. Conclusion: In our experience, we have noticed a specific subgroup of patients who benefit greatly when collagenase enzymatic debridement therapy is combined with NPWT. It is our belief that this combination therapy combines the molecular clearing of non-viable collagen with the wound granulation necessary to advance complex wounds to the next step in healing despite the current paucity in literature discussing this specific pairing.

  10. [Clinical efficacy of negative-pressure wound therapy combined with porcine acellular dermal matrix for repairing deep burn wounds in limbs].

    Science.gov (United States)

    Liu, Wei; Li, Feng; Chen, Xin; Pan, Qing

    2016-06-01

    To observe the clinical efficacy of negative pressure wound therapy (NPWT) in combination with porcine acellular dermal matrix (ADM) dressing for repairing deep burn wounds in limbs of patients with non-surgical treatment. Thirty-two patients with deep partial-thickness burn to full-thickness burn on the limbs admitted to our ward from June 2012 to December 2015, conforming to the inclusion criteria, were divided into group NPWT (n=10, treated with interval negative pressure drainage at -16.6 kPa), group ADM (n=7, treated with porcine ADM dressing), and group NPWT+ ADM (n=15, treated with interval negative pressure drainage and porcine ADM dressing as above) according to the random number table and patient's consent. After being treated for 21 d, residual wounds were cured by routine dressing change using sulfadiazine silver. On post treatment day (PTD) 7, 14, and 21, wound gross observation was conducted, wound drainage fluid volume was recorded, and wound healing rate was calculated. Wound secretion was collected for bacterial culture before treatment and on PTD 21, and bacterial clearance effect was recorded. The wound healing time was also recorded. Measurement data were processed with analysis of variance for repeated measurement, one-way analysis of variance, and LSD test. Eenumeration data were processed with chi-square test or Fisher's exact test. (1) On PTD 7, the wounds of patients in group NPWT and group NPWT+ ADM were significantly shrinked as compared with those before treatment. Skin paddle scattered on the wounds of patients in group NPWT+ ADM on PTD 7. The wounds of patients in group ADM were slightly shrinked on PTD 7 as compared with those before treatment. On PTD 14, the wounds of patients in group NPWT were slightly shrinked as compared with those on PTD 7, while those in group NPWT+ ADM were significantly shrinked as compared with those on PTD 7. Skin paddle on the wounds of patients in group NPWT+ ADM on PTD 14 were increased and fused. The

  11. Basal electric and magnetic fields of celestial bodies come from positive-negative charge separation caused by gravitation of quasi-Casimir pressure in weak interaction

    Science.gov (United States)

    Chen, Shao-Guang

    According to f =d(mv)/dt=m(dv/dt)+ v(dm/dt), a same gravitational formula had been de-duced from the variance in physical mass of QFT and from the variance in mass of inductive energy-transfer of GR respectively: f QF T = f GR = -G (mM/r2 )((r/r)+(v/c)) when their interaction-constants are all taken the experimental values (H05-0029-08, E15-0039-08). f QF T is the quasi-Casimir pressure. f GR is equivalent to Einstein's equation, then more easy to solve it. The hypothesis of the equivalent principle is not used in f QF T , but required by f GR . The predictions of f QF T and f GR are identical except that f QF T has quantum effects but f GR has not and f GR has Lense-Thirring effect but f QF T has not. The quantum effects of gravitation had been verified by Nesvizhevsky et al with the ultracold neutrons falling in the earth's gravitational field in 2002. Yet Lense-Thirring effect had not been measured by GP-B. It shows that f QF T is essential but f GR is phenomenological. The macro-f QF T is the statistic average pressure collided by net virtual neutrinos ν 0 flux (after self-offset in opposite directions) and in direct proportion to the mass. But micro-f QF T is in direct proportion to the scattering section. The electric mass (in inverse proportion to de Broglie wavelength λ) far less than nucleonic mass and the electric scattering section (in direct proportion to λ2 ) far large than that of nucleon, then the net ν 0 flux pressure exerted to electron far large than that to nucleon and the electric displacement far large than that of nucleon, it causes the gravitational polarization of positive-negative charge center separation. Because the gravity far less than the electromagnetic binding force, in atoms the gravitational polarization only produces a little separation. But the net ν 0 flux can press a part freedom electrons in plasma of ionosphere into the earth's surface, the static electric force of redundant positive ions prevents electrons from further

  12. Probabilistic signatures of spatiotemporal intermittency in the ...

    Indian Academy of Sciences (India)

    where spatiotemporal intermittency with travelling wave laminar states and solitons is seen at points marked with boxes (2). (b) The space-time plot of spatiotemporal intermittency with solitons. the strength of nonlinearity in the map and Ω is the frequency of the map in the absence of nonlinearity. The phase diagram of the ...

  13. Intermittent behavior of the logistic system

    Science.gov (United States)

    Mayer-Kress, G.; Haken, H.

    1981-03-01

    In the discrete logistic model a transition to chaotic behavior via intermittency occurs in a neighborhood of periodic bands. Intermittent behavior is also induced if a stable periodic orbit is perturbed by low-level external noise, whereas alterations due to computer digitalisation produce remarkable periodicities. We compare our numerical results with the predictions of Pomeau and Manneville for the Lorenz system.

  14. Probabilistic signatures of spatiotemporal intermittency in the ...

    Indian Academy of Sciences (India)

    with triangles (△) and asterisks (∗). Inset shows a part of the phase diagram where spatiotemporal intermittency with travelling wave laminar states and solitons is seen at points marked with boxes (2). (b) The space-time plot of spatiotemporal intermittency with solitons. the strength of nonlinearity in the map and Ω is the ...

  15. Metabolic syndrome in patients with prostate cancer undergoing intermittent androgen-deprivation therapy.

    Science.gov (United States)

    Rezaei, Mohammadali Mohammadzadeh; Rezaei, Mohammadhadi Mohammadzadeh; Ghoreifi, Alireza; Kerigh, Behzad Feyzzadeh

    2016-01-01

    The presence of metabolic syndrome in men with prostate cancer (PCa) undergoing androgen-deprivation therapy (ADT), especially intermittent type, has not been completely evaluated. The aim of this study is to evaluate metabolic syndrome in men with PCa undergoing intermittent ADT. In this longitudinal study, we studied the prevalence of metabolic syndrome and its components in 190 patients who were undergoing intermittent ADT. The metabolic syndrome was defined according to the Adult Treatment Panel III criteria. All metabolic parameters, including lipid profile, blood glucose, blood pressures, and waist circumferences of the patients were measured six and 12 months after treatment. Mean age of the patients was 67.5 ± 6.74 years. The incidence of metabolic syndrome after six and 12 months was 6.8% and 14.7%, respectively. Analysis of various components of the metabolic syndrome revealed that patients had significantly higher overall prevalence of hyperglycemia, abdominal obesity, and hypertriglyceridemia in their six- and 12-month followups, but blood pressure has not been changed in the same period except for diastolic blood pressure after six months. Although there was an increased risk of metabolic syndrome in patients receiving intermittent ADT, it was lower than other studies that treated the same patients with continuous ADT. Also it seems that intermittent ADT has less metabolic complications than continuous ADT and could be used as a safe alternative in patients with advanced and metastatic PCa.

  16. Cosmic Rays in Intermittent Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Shukurov, Anvar; Seta, Amit; Bushby, Paul J.; Wood, Toby S. [School of Mathematics and Statistics, Newcastle University, Newcastle Upon Tyne NE1 7RU (United Kingdom); Snodin, Andrew P., E-mail: a.seta1@ncl.ac.uk, E-mail: amitseta90@gmail.com [Department of Mathematics, Faculty of Applied Science, King Mongkut’s University of Technology North Bangkok, Bangkok 10800 (Thailand)

    2017-04-10

    The propagation of cosmic rays in turbulent magnetic fields is a diffusive process driven by the scattering of the charged particles by random magnetic fluctuations. Such fields are usually highly intermittent, consisting of intense magnetic filaments and ribbons surrounded by weaker, unstructured fluctuations. Studies of cosmic-ray propagation have largely overlooked intermittency, instead adopting Gaussian random magnetic fields. Using test particle simulations, we calculate cosmic-ray diffusivity in intermittent, dynamo-generated magnetic fields. The results are compared with those obtained from non-intermittent magnetic fields having identical power spectra. The presence of magnetic intermittency significantly enhances cosmic-ray diffusion over a wide range of particle energies. We demonstrate that the results can be interpreted in terms of a correlated random walk.

  17. Clan structure as a source of intermittency in high energy multihadron production

    International Nuclear Information System (INIS)

    Hove, L. van

    1989-01-01

    Recently the systematic study of charged hadron multiplicity distributions in high energy hadronic and leptonic collisions has revealed the general occurrence of negative binomial regularities in symmetric CM rapidity windows and of intermittency in very small windows in the central region. The negative binomial regularities imply a particular form of clustering called clan structure, which embodies all Mueller multiparticle correlations. We show that this clan structure leads to intermittency when the simplest assumptions are made on the behaviour of the clans in very small windows. (orig.)

  18. Prolonged Intermittent Renal Replacement Therapy.

    Science.gov (United States)

    Edrees, Fahad; Li, Tingting; Vijayan, Anitha

    2016-05-01

    Prolonged intermittent renal replacement therapy (PIRRT) is becoming an increasingly popular alternative to continuous renal replacement therapy in critically ill patients with acute kidney injury. There are significant practice variations in the provision of PIRRT across institutions, with respect to prescription, technology, and delivery of therapy. Clinical trials have generally demonstrated that PIRRT is non-inferior to continuous renal replacement therapy regarding patient outcomes. PIRRT offers cost-effective renal replacement therapy along with other advantages such as early patient mobilization and decreased nursing time. However, due to lack of standardization of the procedure, PIRRT still poses significant challenges, especially pertaining to appropriate drug dosing. Future guidelines and clinical trials should work toward developing consensus definitions for PIRRT and ensure optimal delivery of therapy. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  19. Velocity-intermittency structure for wake flow of the pitched single wind turbine under different inflow conditions

    Science.gov (United States)

    Crist, Ryan; Cal, Raul Bayoan; Ali, Naseem; Rockel, Stanislav; Peinke, Joachim; Hoelling, Michael

    2017-11-01

    The velocity-intermittency quadrant method is used to characterize the flow structure of the wake flow in the boundary layer of a wind turbine array. Multifractal framework presents the intermittency as a pointwise Hölder exponent. A 3×3 wind turbine array tested experimentally provided a velocity signal at a 21×9 downstream location, measured via hot-wire anemometry. The results show a negative correlation between the velocity and the intermittency at the hub height and bottom tip, whereas the top tip regions show a positive correlation. Sweep and ejection based on the velocity and intermittency are dominant downstream from the rotor. The pointwise results reflect large-scale organization of the flow and velocity-intermittency events corresponding to a foreshortened recirculation region near the hub height and the bottom tip.

  20. Intermittency in small-scale turbulence: a velocity gradient approach

    Science.gov (United States)

    Meneveau, Charles; Johnson, Perry

    2017-11-01

    Intermittency of small-scale motions is an ubiquitous facet of turbulent flows, and predicting this phenomenon based on reduced models derived from first principles remains an important open problem. Here, a multiple-time scale stochastic model is introduced for the Lagrangian evolution of the full velocity gradient tensor in fluid turbulence at arbitrarily high Reynolds numbers. This low-dimensional model differs fundamentally from prior shell models and other empirically-motivated models of intermittency because the nonlinear gradient self-stretching and rotation A2 term vital to the energy cascade and intermittency development is represented exactly from the Navier-Stokes equations. With only one adjustable parameter needed to determine the model's effective Reynolds number, numerical solutions of the resulting set of stochastic differential equations show that the model predicts anomalous scaling for moments of the velocity gradient components and negative derivative skewness. It also predicts signature topological features of the velocity gradient tensor such as vorticity alignment trends with the eigen-directions of the strain-rate. This research was made possible by a graduate Fellowship from the National Science Foundation and by a Grant from The Gulf of Mexico Research Initiative.

  1. Intermittent Swimming with a Flexible Propulsor

    Science.gov (United States)

    Akoz, Emre; Moored, Keith

    2017-11-01

    Aquatic animals use a variety of swimming gaits to propel themselves efficiently through the oceans. One type of gait known as intermittent or burst-and-coast swimming is used by species such as saithe, cod and trout. Recent studies have shown that this gait can save up to 60% of a swimmer's energy by exploiting an inviscid Garrick mechanism. These detailed studies have examined the effects of an intermittent swimming gait on rigid propulsors, yet the caudal fins of intermittent swimmers are in fact highly flexible propulsors. In this respect, to gain a comprehensive understanding of intermittent swimming, the effect of elasticity on the swimming performance and wake flow of an intermittent swimmer is investigated. To accomplish this a torsional spring structural model is strongly coupled to a fast boundary element method solver that captures the fluid-structure interaction of a two-dimensional self-propelled intermittently pitching hydrofoil. It is shown that flexibility introduces extra vortices to the coasting phase of motion that can either promote or diminish thrust production depending upon the hydrofoil parameters. An optimal intermittent flexible swimmer is shown to increase its efficiency by as much as 28% when compared to an optimal continuous flexible swimmer. Supported by the Office of Naval Research under Program Director Dr. Bob Brizzolara, MURI Grant Number N00014-14-1-0533.

  2. Supine Treadmill Exercise in Lower Body Negative Pressure Combined with Resistive Exercise Counteracts Bone Loss, Reduced Aerobic Upright Exercise Capacity and Reduced Muscle Strength

    Science.gov (United States)

    Meuche, Sabine; Schneider, S. M.; Lee, S. M. C.; Macias, B. R.; Smith, S. M.; Watenpaugh, D. E.; Hargens, A. R.

    2006-01-01

    Long-term exposure to weightlessness leads to cardiovascular and musculoskeletal deconditioning. In this report, the effectiveness of combined supine treadmill exercise in a lower body negative pressure chamber (LBNPex) and flywheel resistive exercise (Rex) countermeasures was determined to prevent bone loss, reduced aerobic upright exercise capacity and reduced muscle strength. We hypothesized that exercise subjects would show less decrease in bone mineral density (BMD), peak oxygen consumption (VO2pk) and knee extensor strength (KES) than control subjects. Sixteen healthy female subjects participated in a 60-d 6(sup 0) head-down tilt bed rest (BR) study after providing written informed consent. Subjects were assigned to one of two groups: a non-exercising control group CON or an exercise group EX performing LBNPex 2-4 d/wk and Rex every 3rd-d. VO2pk was measured with a maximal, graded, upright treadmill test performed pre-BR and on 3-d after BR. BMD was assessed before and 3-d after BR. Isokinetic KES was measured before and 5-d after BR. Two-way repeated measures ANOVA were performed. Statistical significance was set at p less than 0.05. CON experienced a significant decrease in BMD in the trochanter (PRE: 0.670 plus or minus 0.045; POST: 0.646 plus or minus 0.352 g (raised dot) per square centimeter) and in the whole hip (PRE=0.894 plus or minus 0.059; POST: 0.858 plus or minus 0.057 g (raised dot) per square centimeter). BMD also decreased significantly in EX in the trochanter (PRE: 0.753 plus or minus 0.0617; POST: 0.741 plus or minus 0.061 g (raised dot) per square centimeter) and whole hip (PRE: 0.954 plus or minus 0.067; POST: 0.935 plus or minus 0.069 g (raised dot) per square centimeter). BMD losses were significantly less in EX than in CON subjects. VO2pk was significantly decreased in the CON after BR (PRE: 38.0 plus or minus 4.8; POST: 29.9 plus or minus 4.2 ml (raised dot) per kilogram per minute), but not in the EX (PRE: 39.0 plus or minus 2.0; POST

  3. The Acute Effects of Intermittent Light Exposure in the Evening on Alertness and Subsequent Sleep Architecture

    Directory of Open Access Journals (Sweden)

    Minqi Yang

    2018-03-01

    Full Text Available Exposure to bright light is typically intermittent in our daily life. However, the acute effects of intermittent light on alertness and sleep have seldom been explored. To investigate this issue, we employed within-subject design and compared the effects of three light conditions: intermittent bright light (30-min pulse of blue-enriched bright light (~1000 lux, ~6000 K alternating with 30-min dim normal light (~5 lux, ~3600 K three times; continuous bright light; and continuous dim light on subjective and objective alertness and subsequent sleep structure. Each light exposure was conducted during the three hours before bedtime. Fifteen healthy volunteers (20 ± 3.4 years; seven males were scheduled to stay in the sleep laboratory for four separated nights (one for adaptation and the others for the light exposures with a period of at least one week between nights. The results showed that when compared with dim light, both intermittent light and continuous bright light significantly increased subjective alertness and decreased sleep efficiency (SE and total sleep time (TST. Intermittent light significantly increased objective alertness than dim light did during the second half of the light-exposure period. Our results suggested that intermittent light was as effective as continuous bright light in their acute effects in enhancing subjective and objective alertness and in negatively impacting subsequent sleep.

  4. Assessing Relative Volatility/Intermittency/Energy Dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko; Schmiegel, Jürgen

    process in particular. While this estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, we apply it also to energy price data. Moreover, we develop a probabilistic asymptotic theory for relative power variations of Brownian semistationary......We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency even when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...... processes and Ito semimartingales and discuss how it can be used for inference on relative volatility/intermittency....

  5. Intermittent cranial lung herniation in two dogs.

    Science.gov (United States)

    Guglielmini, Carlo; De Simone, Antonio; Valbonetti, Luca; Diana, Alessia

    2007-01-01

    Two aged dogs with chronic obstructive airway disease were evaluated because of intermittent swelling of the ventral cervical region. Radiographs made at expiration and caudal positioning of the forelimbs allowed identification of intermittent cervical lung herniation of the left and right cranial lung lobe in both dogs. Pulmonary hyperinflation, increased expiratory effort, and chronic coughing were considered responsible for the lung herniation. Cervical lung hernia should be included in the differential diagnoses of intermittent cervical swelling in dogs with chronic respiratory disorders associated with increased expiratory effort and chronic coughing.

  6. Lenses generated by intermittent currents

    Science.gov (United States)

    Nof, Doron

    1991-03-01

    A nonlinear mechanism for the generation of anticyclonic lens-like eddies from boundary currents is proposed. In contrast to the familiar generation processes that rely on unstable long waves that grow and close upon themselves or vortex shedding due to the geometry of the boundary, the present mechanism is related to intermittency in the current's mass transport. The essence of the new mechanism is that intermittencies in the transport (such as those in the Denmark Strait or the Mediterranean outflow) lead to unbalanced patches of fluid which break up into a discrete sets of eddies that interact with the boundary. The process is highly nonlinear because both the amplitude and the Rossby number are of order unity. It is modeled as follows: we begin with a rectangular box containing the motionless (light) fluid near the boundary. At, say, t = 0, the conceptual box is removed the unbalanced fluid undergoes two main processes. The first involves the establishment of a set of eddies via breakup and geostrophic adjustment, whereas the second is associated with the interaction of the set with the wall. These two processes are examined independently even though in reality the processes are, obviously, taking place at the same time. To examine the first processes we consider the nonlinear collapse of a (light) rectangular box in the open ocean away from the boundary. The breakup processes involves, of course, some sort of instability (because the patch does not remain intact) but this is not necessarily related to the long wave instability that is usually associated with long gravity currents. The general structures of the resulting final chain of eddies can be computed analytically by using the usual connecting principles, the conservation of potential vorticity and mass. It turns out, however, that the number of eddies and their detailed structure cannot be computed unless one invokes an additional constraint. To resolve this closure difficulty, the integrated angular

  7. Efficacy and safety of active negative pressure peritoneal therapy for reducing the systemic inflammatory response after damage control laparotomy (the Intra-peritoneal Vacuum Trial): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Roberts, Derek J; Jenne, Craig N; Ball, Chad G; Tiruta, Corina; Léger, Caroline; Xiao, Zhengwen; Faris, Peter D; McBeth, Paul B; Doig, Christopher J; Skinner, Christine R; Ruddell, Stacy G; Kubes, Paul; Kirkpatrick, Andrew W

    2013-05-16

    Damage control laparotomy, or abbreviated initial laparotomy followed by temporary abdominal closure (TAC), intensive care unit resuscitation, and planned re-laparotomy, is frequently used to manage intra-abdominal bleeding and contamination among critically ill or injured adults. Animal data suggest that TAC techniques that employ negative pressure to the peritoneal cavity may reduce the systemic inflammatory response and associated organ injury. The primary objective of this study is to determine if use of a TAC dressing that affords active negative pressure peritoneal therapy, the ABThera Open Abdomen Negative Pressure Therapy System, reduces the extent of the systemic inflammatory response after damage control laparotomy for intra-abdominal sepsis or injury as compared to a commonly used TAC method that provides potentially less efficient peritoneal negative pressure, the Barker's vacuum pack. The Intra-peritoneal Vacuum Trial will be a single-center, randomized controlled trial. Adults will be intraoperatively allocated to TAC with either the ABThera or Barker's vacuum pack after the decision has been made by the attending surgeon to perform a damage control laparotomy. The study will use variable block size randomization. On study days 1, 2, 3, 7, and 28, blood will be collected. Whenever possible, peritoneal fluid will also be collected at these time points from the patient's abdomen or TAC device. Luminex technology will be used to quantify the concentrations of 65 mediators relevant to the inflammatory response in peritoneal fluid and plasma. The primary endpoint is the difference in the plasma concentration of the pro-inflammatory cytokine IL-6 at 24 and 48 h after TAC dressing application. Secondary endpoints include the differential effects of these dressings on the systemic concentration of other pro-inflammatory cytokines, collective peritoneal and systemic inflammatory mediator profiles, postoperative fluid balance, intra-abdominal pressure, and

  8. A botanical compound, Padma 28, increases walking distance in stable intermittent claudication

    DEFF Research Database (Denmark)

    Drabaek, H; Mehlsen, J; Himmelstrup, H

    1993-01-01

    Thirty-six patients with a median age of sixty-seven years and a median duration of intermittent claudication of five years were randomized to either active treatment with Padma 28 or placebo. The effect of treatment was quantified by measurements of systemic and peripheral systolic blood pressur...

  9. Inactivation of Gram-Negative Bacteria by Low-Pressure RF Remote Plasma Excited in N2-O2 Mixture and SF6 Gases

    Directory of Open Access Journals (Sweden)

    Ayman Al-Mariri

    2013-12-01

    Full Text Available The role of low-pressure RF plasma in the inactivation of Escherichia coli O157, Klebsiella pneumoniae, Proteus mirabilis, and Enterobacter sakazakii using N2-O2 and SF6 gases was assessed. 1×109 colony-forming units (CFUs of each bacterial isolate were placed on three polymer foils. The effects of pressure, power, distance from the source, and exposure time to plasma gases were optimized. The best conditions to inactivate the four bacteria were a 91%N2-9%O2 mixture and a 30-minute exposure time. SF6 gas was more efficient for all the tested isolates in as much as the treatment time was reduced to only three minutes. Therefore, low-pressure plasma could be used to sterilize heat and/or moisture-sensitive medical instruments.

  10. Structures of Bordered Pits Potentially Contributing to Isolation of a Refilled Vessel from Negative Xylem Pressure in Stems of Morus australis Poir.: Testing of the Pit Membrane Osmosis and Pit Valve Hypotheses.

    Science.gov (United States)

    Ooeda, Hiroki; Terashima, Ichiro; Taneda, Haruhiko

    2017-02-01

    Two hypotheses have been proposed to explain the mechanism preventing the refilling vessel water from being drained to the neighboring functional vessels under negative pressure. The pit membrane osmosis hypothesis proposes that the xylem parenchyma cells release polysaccharides that are impermeable to the intervessel pit membranes into the refilling vessel; this osmotically counteracts the negative pressure, thereby allowing the vessel to refill. The pit valve hypothesis proposes that gas trapped within intervessel bordered pits isolates the refilling vessel water from the surrounding functional vessels. Here, using the single-vessel method, we assessed these hypotheses in shoots of mulberry (Morus australis Poir.). First, we confirmed the occurrence of xylem refilling under negative pressure in the potted mulberry saplings. To examine the pit membrane osmosis hypothesis, we estimated the semi-permeability of pit membranes for molecules of various sizes and found that the pit membranes were not semi-permeable to polyethylene glycol of molecular mass osmosis mechanism in mulberry would be unrealistically large. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Intermittent sea-level acceleration

    Science.gov (United States)

    Olivieri, M.; Spada, G.

    2013-10-01

    Using instrumental observations from the Permanent Service for Mean Sea Level (PSMSL), we provide a new assessment of the global sea-level acceleration for the last ~ 2 centuries (1820-2010). Our results, obtained by a stack of tide gauge time series, confirm the existence of a global sea-level acceleration (GSLA) and, coherently with independent assessments so far, they point to a value close to 0.01 mm/yr2. However, differently from previous studies, we discuss how change points or abrupt inflections in individual sea-level time series have contributed to the GSLA. Our analysis, based on methods borrowed from econometrics, suggests the existence of two distinct driving mechanisms for the GSLA, both involving a minority of tide gauges globally. The first effectively implies a gradual increase in the rate of sea-level rise at individual tide gauges, while the second is manifest through a sequence of catastrophic variations of the sea-level trend. These occurred intermittently since the end of the 19th century and became more frequent during the last four decades.

  12. Social Smoking among Intermittent Smokers

    Science.gov (United States)

    Shiffman, Saul; Li, Xiaoxue; Dunbar, Michael S.; Ferguson, Stuart G.; Tindle, Hilary A.; Scholl, Sarah M.

    2015-01-01

    Background “Social smoking” - smoking mostly or even only with others – may be an important pattern that implies smoking motivated extrinsically by social influences. Non-daily smokers (intermittent smokers; ITS) are often assumed to be social smokers, with some authors even assuming that all ITS are social smokers (SS+). We sought to identify and characterize social smokers in a sample of ITS. Methods 204 adult ITS (smoking 4–27 days/month) recorded the circumstances of smoking in their natural settings using Ecological Momentary Assessment, while also recording their circumstances in nonsmoking moments. SS+ were defined as ITS who were with others when they smoked most of their cigarettes, and who were ≥ 50% more likely to be with others when smoking than when not. Results Only 13% of ITS were SS+. Although defined solely on the basis of presence of others, SS+ showed a distinct pattern of smoking across multiple dimensions: Compared to other ITS (who were significantly less likely to smoke when with others), SS+ smoking was more associated with socializing, being with friends and acquaintances, drinking alcohol, weekends, evening or nighttime, being in other people’s homes, but not their own home. SS+ smoking was low in the morning and increased in the evening. SS+ smoked fewer days/week and were less dependent, but did not differ demographically. Conclusions Social smoking does constitute a highly distinct smoking pattern, but is not common among adult ITS. PMID:26205313

  13. On-line intermittent connector anomaly detection

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper investigates a non-traditional use of differential current sensor and current sensor to detect intermittent disconnection problems in connectors. An...

  14. Intermittent chaotic chimeras for coupled rotators

    DEFF Research Database (Denmark)

    Olmi, Simona; Martens, Erik Andreas; Thutupalli, Shashi

    2015-01-01

    Two symmetrically coupled populations of N oscillators with inertia m display chaotic solutions with broken symmetry similar to experimental observations with mechanical pendulums. In particular, we report evidence of intermittent chaotic chimeras, where one population is synchronized and the other...

  15. Bladder Management in Children: Intermittent Catheterization Education.

    Science.gov (United States)

    Fortuna, Suzanne Marie; Korcal, Layna; Thomas, Ginger

    2018-03-01

    Clean intermittent catheterization (IC) of the bladder is one example of advanced medical care required by students with special health care needs. The success of a child's intermittent catheterization program in a community setting such as a school is dependent on an educated team. This article discusses indications and problems that arise with IC bladder management in the pediatric population. The article also provides information about current best practice for IC management to assist school nurses in the optimization of bladder health.

  16. Investigations on Cs-free alternatives for negative ion formation in a low pressure hydrogen discharge at ion source relevant parameters

    Science.gov (United States)

    Kurutz, U.; Friedl, R.; Fantz, U.

    2017-07-01

    Caesium (Cs) is applied in high power negative hydrogen ion sources to reduce a converter surface’s work function and thus enabling an efficient negative ion surface formation. Inherent drawbacks with the usage of this reactive alkali metal motivate the search for Cs-free alternative materials for neutral beam injection systems in fusion research. In view of a future DEMOnstration power plant, a suitable material should provide a high negative ion formation efficiency and comply with the RAMI issues of the system: reliability, availability, maintainability, inspectability. Promising candidates, like low work function materials (molybdenum doped with lanthanum (MoLa) and LaB6), as well as different non-doped and boron-doped diamond samples were investigated in this context at identical and ion source relevant parameters at the laboratory experiment HOMER. Negative ion densities were measured above the samples by means of laser photodetachment and compared with two reference cases: pure negative ion volume formation with negative ion densities of about 1× {10}15 {{{m}}}-3 and the effect of H- surface production using an in situ caesiated stainless steel sample which yields 2.5 times higher densities. Compared to pure volume production, none of the diamond samples did exhibit a measurable increase in H- densities, while showing clear indications of plasma-induced erosion. In contrast, both MoLa and LaB6 produced systematically higher densities (MoLa: ×1.60 LaB6: ×1.43). The difference to caesiation can be attributed to the higher work functions of MoLa and LaB6 which are expected to be about 3 eV for both compared to 2.1 eV of a caesiated surface.

  17. Investigation of the effect of mechanical pressure on the performance of negative lead accumulator electrodes during partial state of charge operation

    Czech Academy of Sciences Publication Activity Database

    Bača, P.; Micka, Karel; Křivík, P.; Tonar, K.; Tošer, P.

    2012-01-01

    Roč. 207, JUN 1 2012 (2012), s. 37-44 ISSN 0378-7753 Institutional research plan: CEZ:AV0Z40400503 Keywords : Lead battery electrodes * Doping with carbon or titanium dioxide * Effect of mechanical pressure Subject RIV: CG - Electrochemistry Impact factor: 4.675, year: 2012

  18. Hypoxia in a neonate caused by intermittent positive pressure ventilation.

    OpenAIRE

    Beddis, I R; Silverman, M

    1980-01-01

    A newborn baby receiving mechanical ventilation was noted to have an extremely variable degree of hypoxia, despite the administration of 100% oxygen. The hypoxia was relieved rapidly when mechanical ventilation was withdrawn.

  19. Exercise training for intermittent claudication.

    Science.gov (United States)

    McDermott, Mary M

    2017-11-01

    The objective of this study was to provide an overview of evidence regarding exercise therapies for patients with lower extremity peripheral artery disease (PAD). This manuscript summarizes the content of a lecture delivered as part of the 2016 Crawford Critical Issues Symposium. Multiple randomized clinical trials demonstrate that supervised treadmill exercise significantly improves treadmill walking performance in people with PAD and intermittent claudication symptoms. A meta-analysis of 25 randomized trials demonstrated a 180-meter increase in treadmill walking distance in response to supervised exercise interventions compared with a nonexercising control group. Supervised treadmill exercise has been inaccessible to many patients with PAD because of lack of medical insurance coverage. However, in 2017, the Centers for Medicare and Medicaid Services issued a decision memorandum to support health insurance coverage of 12 weeks of supervised treadmill exercise for patients with walking impairment due to PAD. Recent evidence also supports home-based walking exercise to improve walking performance in people with PAD. Effective home-exercise programs incorporate behavioral change interventions such as a remote coach, goal setting, and self-monitoring. Supervised treadmill exercise programs preferentially improve treadmill walking performance, whereas home-based walking exercise programs preferentially improve corridor walking, such as the 6-minute walk test. Clinical trial evidence also supports arm or leg ergometry exercise to improve walking endurance in people with PAD. Treadmill walking exercise appears superior to resistance training alone for improving walking endurance. Supervised treadmill exercise significantly improves treadmill walking performance in people with PAD by approximately 180 meters compared with no exercise. Recent evidence suggests that home-based exercise is also effective and preferentially improves over-ground walking performance, such as

  20. When negation is not negation

    OpenAIRE

    Milicevic, Nataša

    2008-01-01

    In this paper I will discuss the formation of different types of yes/no questions in Serbian (examples in (1)), focusing on the syntactically and semantically puzzling example (1d), which involves the negative auxiliary inversion. Although there is a negative marker on the fronted auxiliary, the construction does not involve sentential negation. This coincides with the fact that the negative quantifying NPIs cannot be licensed. The question formation and sentential negation have similar synta...

  1. Implementation of Environmental Flows for Intermittent River Systems: Adaptive Management and Stakeholder Participation Facilitate Implementation

    Science.gov (United States)

    Conallin, John; Wilson, Emma; Campbell, Josh

    2018-03-01

    Anthropogenic pressure on freshwater ecosystems is increasing, and often leading to unacceptable social-ecological outcomes. This is even more prevalent in intermittent river systems where many are already heavily modified, or human encroachment is increasing. Although adaptive management approaches have the potential to aid in providing the framework to consider the complexities of intermittent river systems and improve utility within the management of these systems, success has been variable. This paper looks at the application of an adaptive management pilot project within an environmental flows program in an intermittent stream (Tuppal Creek) in the Murray Darling Basin, Australia. The program focused on stakeholder involvement, participatory decision-making, and simple monitoring as the basis of an adaptive management approach. The approach found that by building trust and ownership through concentrating on inclusiveness and transparency, partnerships between government agencies and landholders were developed. This facilitated a willingness to accept greater risks and unintended consequences allowing implementation to occur.

  2. Community response to intermittent preventive treatment of malaria in infants (IPTi in Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Senn Nicolas

    2010-12-01

    Full Text Available Abstract Background Building on previous acceptability research undertaken in sub-Saharan Africa this article aims to investigate the acceptability of intermittent preventive treatment of malaria in infants (IPTi in Papua New Guinea (PNG. Methods A questionnaire was administered to mothers whose infants participated in the randomised placebo controlled trial of IPTi. Mothers whose infants participated and who refused to participate in the trial, health workers, community reporters and opinion leaders were interviewed. Men and women from the local community also participated in focus group discussions. Results Respondents viewed IPTi as acceptable in light of wider concern for infant health and the advantages of trial participation. Mothers reported complying with at-home administration of IPTi due to perceived benefits of IPTi and pressure from health workers. In spite of patchy knowledge, respondents also demonstrated a demand for infant vaccinations and considered non-vaccination to be neglect. There is little evidence that IPTi has negative impacts on attitudes to EPI, EPI adherence or existing malaria prevention practices. Conclusion The degree of similarity between findings from the acceptability studies undertaken in sub-Saharan Africa and PNG allows some generalization relating to the implementation of IPTi outside of Africa: IPTi fits well with local health cultures, appears to be accepted easily and has little impact on attitudes towards EPI or malaria prevention. The study adds to the evidence indicating that IPTi could be rolled out in a range of social and cultural contexts.

  3. Can Mathematical Models Predict the Outcomes of Prostate Cancer Patients Undergoing Intermittent Androgen Deprivation Therapy?

    Science.gov (United States)

    Everett, R. A.; Packer, A. M.; Kuang, Y.

    Androgen deprivation therapy is a common treatment for advanced or metastatic prostate cancer. Like the normal prostate, most tumors depend on androgens for proliferation and survival but often develop treatment resistance. Hormonal treatment causes many undesirable side effects which significantly decrease the quality of life for patients. Intermittently applying androgen deprivation in cycles reduces the total duration with these negative effects and may reduce selective pressure for resistance. We extend an existing model which used measurements of patient testosterone levels to accurately fit measured serum prostate specific antigen (PSA) levels. We test the model's predictive accuracy, using only a subset of the data to find parameter values. The results are compared with those of an existing piecewise linear model which does not use testosterone as an input. Since actual treatment protocol is to re-apply therapy when PSA levels recover beyond some threshold value, we develop a second method for predicting the PSA levels. Based on a small set of data from seven patients, our results showed that the piecewise linear model produced slightly more accurate results while the two predictive methods are comparable. This suggests that a simpler model may be more beneficial for a predictive use compared to a more biologically insightful model, although further research is needed in this field prior to implementing mathematical models as a predictive method in a clinical setting. Nevertheless, both models are an important step in this direction.

  4. Intermittent hypoxia alters gut microbiota diversity in a mouse model of sleep apnoea.

    Science.gov (United States)

    Moreno-Indias, Isabel; Torres, Marta; Montserrat, Josep M; Sanchez-Alcoholado, Lidia; Cardona, Fernando; Tinahones, Francisco J; Gozal, David; Poroyko, Valeryi A; Navajas, Daniel; Queipo-Ortuño, Maria I; Farré, Ramon

    2015-04-01

    We assessed whether intermittent hypoxia, which emulates one of the hallmarks of obstructive sleep apnoea (OSA), leads to altered faecal microbiome in a murine model. In vivo partial pressure of oxygen was measured in colonic faeces during intermittent hypoxia in four anesthetised mice. 10 mice were subjected to a pattern of chronic intermittent hypoxia (20 s at 5% O2 and 40 s at room air for 6 h·day(-1)) for 6 weeks and 10 mice served as normoxic controls. Faecal samples were obtained and microbiome composition was determined by 16S rRNA pyrosequencing and bioinformatic analysis by Quantitative Insights into Microbial Ecology. Intermittent hypoxia exposures translated into hypoxia/re-oxygenation patterns in the faeces proximal to the bowel epithelium (diversity (Shannon index, pgut microbiota (ANOSIM analysis of β-diversity, pdiversity are altered as a result of intermittent hypoxia realistically mimicking OSA, suggesting the possibility that physiological interplays between host and gut microbiota could be deregulated in OSA. Copyright ©ERS 2015.

  5. Pressure ulcers : predicting factors, prevention and costs

    OpenAIRE

    Demarré, Liesbet

    2014-01-01

    The research outline pursued with this thesis can be divided in three parts. In the first part, studies to compare the effectiveness of several interventions for the prevention of pressure ulcers were conducted. Pressure ulcer prevention focusses on the reduction of the amount and duration of pressure and shear. An alternating device intermittently removes pressure and shear from vulnerable areas. It provides pressure relief via cyclic inflating and deflating air cells. Systematic reviews an...

  6. Spontaneous breathing trial in T-tube negatively impact on autonomic modulation of heart rate compared with pressure support in critically ill patients.

    Science.gov (United States)

    Güntzel Chiappa, Adriana M; Chiappa, Gaspar R; Cipriano, Gerson; Moraes, Ruy S; Ferlin, Elton L; Borghi-Silva, Audrey; Vieira, Silvia R

    2017-07-01

    Spontaneous breathing with a conventional T-piece (TT) connected to the tracheal tube orotraqueal has been frequently used in clinical setting to weaning of mechanical ventilation (MV), when compared with pressure support ventilation (PSV). However, the acute effects of spontaneous breathing with TT versus PSV on autonomic function assessed through heart rate variability (HRV) have not been fully elucidated. The purpose of this study was to examine the acute effects of spontaneous breathing in TT vs PSV in critically ill patients. Twenty-one patients who had received MV for ≥ 48 h and who met the study inclusion criteria for weaning were assessed. Eligible patients were randomized to TT and PSV. Cardiorespiratory responses (respiratory rate -ƒ, tidal volume-V T , mean blood pressure (MBP) and diastolic blood pressure (DBP), end tidal dioxide carbone (P ET CO 2 ), peripheral oxygen saturation (SpO 2 ) and HRV indices in frequency domain (low-LF, high frequency (HF) and LF/HF ratio were evaluated. TT increased ƒ (20 ± 5 vs 25 ± 4 breaths/min, P<0.05), MBP (90 ± 14 vs 94 ± 18 mmHg, P<0.05), HR (90 ± 17 vs 96 ± 12 beats/min, P<0.05), P ET CO 2 (33 ± 8 vs 48 ± 10 mmHg, P<0.05) and reduced SpO 2 (98 ± 1.6 vs 96 ± 1.6%, P<0.05). In addition, LF increased (47 ± 18 vs 38 ± 12 nu, P<0.05) and HF reduced (29 ± 13 vs 32 ± 16 nu, P<0.05), resulting in higher LF/HF ratio (1.62 ± 2 vs 1.18 ± 1, P<0.05) during TT. Conversely, V T increased with PSV (0.58 ± 0.16 vs 0.50 ± 0.15 L, P<0.05) compared with TT. Acute effects of TT mode may be closely linked to cardiorespiratory mismatches and cardiac autonomic imbalance in critically ill patients. © 2015 John Wiley & Sons Ltd.

  7. The Yo-Yo intermittent recovery test

    DEFF Research Database (Denmark)

    Bangsbo, Jens; Iaia, F. Marcello; Krustrup, Peter

    2008-01-01

    The two Yo-Yo intermittent recovery (IR) tests evaluate an individual's ability to repeatedly perform intense exercise. The Yo-Yo IR level 1 (Yo-Yo IR1) test focuses on the capacity to carry out intermittent exercise leading to a maximal activation of the aerobic system, whereas Yo-Yo IR level 2...... (Yo-Yo IR2) determines an individual's ability to recover from repeated exercise with a high contribution from the anaerobic system. Evaluations of elite athletes in various sports involving intermittent exercise showed that the higher the level of competition the better an athlete performs in the Yo......-Yo IR tests. Performance in the Yo-Yo IR tests for young athletes increases with rising age. The Yo-Yo IR tests have shown to be a more sensitive measure of changes in performance than maximum oxygen uptake. The Yo-Yo IR tests provide a simple and valid way to obtain important information...

  8. Assessing relative volatility/intermittency/energy dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko S.; Schmiegel, Jürgen

    2014-01-01

    process in particular. This estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, but it is also applicable in other areas. We develop a probabilistic asymptotic theory for realised relative power variations of Brownian semistationary processes......, and introduce inference methods based on the theory. We also discuss how to extend the asymptotic theory to other classes of processes exhibiting stochastic volatility/intermittency. As an empirical application, we study relative energy dissipation in data of atmospheric turbulence.......We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...

  9. Forces and energetics of intermittent swimming

    Science.gov (United States)

    Floryan, Daniel; Van Buren, Tyler; Smits, Alexander J.

    2017-08-01

    Experiments are reported on intermittent swimming motions. Water tunnel experiments on a nominally two-dimensional pitching foil show that the mean thrust and power scale linearly with the duty cycle, from a value of 0.2 all the way up to continuous motions, indicating that individual bursts of activity in intermittent motions are independent of each other. This conclusion is corroborated by particle image velocimetry (PIV) flow visualizations, which show that the main vortical structures in the wake do not change with duty cycle. The experimental data also demonstrate that intermittent motions are generally energetically advantageous over continuous motions. When metabolic energy losses are taken into account, this conclusion is maintained for metabolic power fractions less than 1.

  10. Unsteady propulsion by an intermittent swimming gait

    Science.gov (United States)

    Akoz, Emre; Moored, Keith W.

    2018-01-01

    Inviscid computational results are presented on a self-propelled swimmer modeled as a virtual body combined with a two-dimensional hydrofoil pitching intermittently about its leading edge. Lighthill (1971) originally proposed that this burst-and-coast behavior can save fish energy during swimming by taking advantage of the viscous Bone-Lighthill boundary layer thinning mechanism. Here, an additional inviscid Garrick mechanism is discovered that allows swimmers to control the ratio of their added mass thrust-producing forces to their circulatory drag-inducing forces by decreasing their duty cycle, DC, of locomotion. This mechanism can save intermittent swimmers as much as 60% of the energy it takes to swim continuously at the same speed. The inviscid energy savings are shown to increase with increasing amplitude of motion, increase with decreasing Lighthill number, Li, and switch to an energetic cost above continuous swimming for sufficiently low DC. Intermittent swimmers are observed to shed four vortices per cycle that form into groups that are self-similar with the DC. In addition, previous thrust and power scaling laws of continuous self-propelled swimming are further generalized to include intermittent swimming. The key is that by averaging the thrust and power coefficients over only the bursting period then the intermittent problem can be transformed into a continuous one. Furthermore, the intermittent thrust and power scaling relations are extended to predict the mean speed and cost of transport of swimmers. By tuning a few coefficients with a handful of simulations these self-propelled relations can become predictive. In the current study, the mean speed and cost of transport are predicted to within 3% and 18% of their full-scale values by using these relations.

  11. The Yo-Yo intermittent recovery test

    DEFF Research Database (Denmark)

    Bangsbo, Jens; Iaia, F. Marcello; Krustrup, Peter

    2008-01-01

    The two Yo-Yo intermittent recovery (IR) tests evaluate an individual's ability to repeatedly perform intense exercise. The Yo-Yo IR level 1 (Yo-Yo IR1) test focuses on the capacity to carry out intermittent exercise leading to a maximal activation of the aerobic system, whereas Yo-Yo IR level 2......-Yo IR tests. Performance in the Yo-Yo IR tests for young athletes increases with rising age. The Yo-Yo IR tests have shown to be a more sensitive measure of changes in performance than maximum oxygen uptake. The Yo-Yo IR tests provide a simple and valid way to obtain important information...

  12. Sprint cycling training improves intermittent run performance

    OpenAIRE

    Hardaway Chun-Kwan Chan; Weeraya Ka-Yan Ho; Patrick Shu-Hang Yung

    2018-01-01

    Background/Objective: The aim of this study was to examine the effect of sprint cycling training on the intermittent run performance, sprinting speed, and change of direction (COD) ability of recreational intermittent sports athletes. Methods: Sixteen participants participated in the study. The experimental group (EG, n = 8) received a total of 12 sessions of sprint cycling training in a 4-week period and the control group (CG, n = 8) received no training. Both EG and CG were instructed to...

  13. Investigation of intermittency in simulated and experimental turbulence data by wavelet analysis

    International Nuclear Information System (INIS)

    Mahdizadeh, N.; Ramisch, M.; Stroth, U.; Lechte, C.; Scott, B.D.

    2004-01-01

    Turbulent transport in magnetized plasmas has an intermittent nature. Peaked probability density functions and a 1/frequency decay of the power spectra have been interpreted as signs of self-organized criticality generated, similar to a sand pile, by the critical gradients of ion- (ITG) or electron-temperature-gradient (ETG) driven instabilities. In order to investigate the degree of intermittency in toroidally confined plasmas in the absence of critical pressure or temperature gradients, data from the drift-Alfven-wave turbulence code DALF3 [B. Scott, Plasma Phys. Controlled Fusion 39, 1635 (1997)], running with a fixed background pressure gradient, and from a weakly driven low-temperature plasma are analyzed. The intermittency is studied on different temporal scales, which are separated by a wavelet transform. Simulated and experimental data reproduce the results on intermittent transport found in fusion plasmas. It can therefore be expected that in fusion plasmas, too, a substantial fraction of the bursty nature of turbulent transport is not related to avalanches caused by a critical gradient as generated by ITG or ETG turbulence

  14. Persistent negative temperature response of mesophyll conductance in red raspberry (Rubus idaeus L.) leaves under both high and low vapour pressure deficits: a role for abscisic acid?

    Science.gov (United States)

    Qiu, Changpeng; Ethier, Gilbert; Pepin, Steeve; Dubé, Pascal; Desjardins, Yves; Gosselin, André

    2017-09-01

    The temperature dependence of mesophyll conductance (g m ) was measured in well-watered red raspberry (Rubus idaeus L.) plants acclimated to leaf-to-air vapour pressure deficit (VPDL) daytime differentials of contrasting amplitude, keeping a fixed diurnal leaf temperature (T leaf ) rise from 20 to 35 °C. Contrary to the great majority of g m temperature responses published to date, we found a pronounced reduction of g m with increasing T leaf irrespective of leaf chamber O 2 level and diurnal VPDL regime. Leaf hydraulic conductance was greatly enhanced during the warmer afternoon periods under both low (0.75 to 1.5 kPa) and high (0.75 to 3.5 kPa) diurnal VPDL regimes, unlike stomatal conductance (g s ), which decreased in the afternoon. Consequently, the leaf water status remained largely isohydric throughout the day, and therefore cannot be evoked to explain the diurnal decrease of g m . However, the concerted diurnal reductions of g m and g s were well correlated with increases in leaf abscisic acid (ABA) content, thus suggesting that ABA can induce a significant depression of g m under favourable leaf water status. Our results challenge the view that the temperature dependence of g m can be explained solely from dynamic leaf anatomical adjustments and/or from the known thermodynamic properties of aqueous solutions and lipid membranes.​. © 2017 John Wiley & Sons Ltd.

  15. Antral hyperplastic polyp causing intermittent gastric outlet obstruction: Case report

    Directory of Open Access Journals (Sweden)

    Kurtkaya-Yapicier Ozlem

    2003-06-01

    Full Text Available Abstract Background Hyperplastic polyps are the most common polypoid lesions of the stomach. Rarely, they cause gastric outlet obstruction by prolapsing through the pyloric channel, when they arise in the prepyloric antrum. Case presentation A 62-year-old woman presented with intermittent nausea and vomiting of 4 months duration. Upper gastrointestinal endoscopy revealed a 30 mm prepyloric sessile polyp causing intermittent gastric outlet obstruction. Following submucosal injection of diluted adrenaline solution, the polyp was removed with a snare. Multiple biopsies were taken from the greater curvature of the antrum and the corpus. Rapid urease test for Helicobacter pylori yielded a negative result. Histopathologic examination showed a hyperplastic polyp without any evidence of malignancy. Biopsies of the antrum and the corpus revealed gastritis with neither atrophic changes nor Helicobacter pylori infection. Follow-up endoscopy after a 12-week course of proton pomp inhibitor therapy showed a complete healing without any remnant tissue at the polypectomy site. The patient has been symptom-free during 8 months of follow-up. Conclusions Symptomatic gastric polyps should be removed preferentially when they are detected at the initial diagnostic endoscopy. Polypectomy not only provides tissue to determine the exact histopathologic type of the polyp, but also achieves radical treatment.

  16. Negative ... concord?

    NARCIS (Netherlands)

    Giannakidou, A

    The main claim of this paper is that a general theory of negative concord (NC) should allow for the possibility of NC involving scoping of a universal quantifier above negation. I propose that Greek NC instantiates this option. Greek n-words will be analyzed as polarity sensitive universal

  17. Effects of 10 days 6 degrees head-down tilt on the responses to fluid loading and lower body negative pressure

    Science.gov (United States)

    Baisch, F.; Heer, M.; Beck, L.; Blomqvist, C. G.; Kropp, J.; Schulz, H.; Hillebrecht, A.; Meyer, M.

    1991-01-01

    In an international collaborative project six normal male subjects were studied before, during and after 10 days 6 degrees HDT. Fluid intake was controlled at 40 ml/(kgbw day). Urine volume and body weight were determined daily. Fluid loading and LBNP were performed in all three phases of the study. Body weight diminished by 2.6% because of fluid loss. Blood volume diminished by 13%. The responses to fluid loading were similar in the three phases of the study. Sixty minutes after end of infusion only 5.5% of the infused saline remained in the intravascular compartment. Excess interstitial fluid was eliminated in the next 24 hs but a negative balance was recorded also in the following day. The compliance of the lower limbs expressed as the rate of limb volume change/unit LBNP change was increased at the end of the HDT phase and during the post HDT phase. The set point of intravascular volume was defended, as shown by the response to FL. HDT increased the compliance of the lower limbs.

  18. Fractal structures and intermittency in QCD

    International Nuclear Information System (INIS)

    Gustafson, Goesta.

    1990-04-01

    New results are presented for fractal structures and intermittency in QCD parton showers. A geometrical interpretation of the anomalous dimension in QCD is given. It is shown that model predications for factorial moments in the PEP-PETRA energy range are increased. if the properties of directly produced pions are more carefully taken into account

  19. Intermittent mechanical and clinical intravalvar regurgitation aortic ...

    African Journals Online (AJOL)

    due to intravalvar occlusion caused by thrombosis and/or tissue ingrowth or to periprosthetic regurgitation. .... position). A. The tilting disc of the prosthetic aortic valve is in the normal closed position during diastole. B. The disc is 'stuck' in the open position during diastole. Intermittent AR in patients with aortic prosthetic ...

  20. Intermittent and global transitions in plasma turbulence

    International Nuclear Information System (INIS)

    Vlad, M.; Spineanu, F.; Itoh, K.; Itoh, S.-I.

    2003-07-01

    The dynamics of the transition processes in plasma turbulence described by the nonlinear Langevin equation (1) is studied. We show that intermittent or global transitions between metastable states can appear. The conditions for the generation of these transitions and their statistical characteristics are determined. (author)

  1. Acute intermittent porphyria presenting as progressive muscular ...

    African Journals Online (AJOL)

    Acute intermittent porphyria, the most common porphyria affecting the nervous system, typically presents with neurovisceral crises followed by a motor neuropathy. We describe a 23-year-old black South African man presenting with a progressive stuttering, lower motor neuron syndrome developing over months. He had not ...

  2. Walking training for intermittent claudication in diabetes

    NARCIS (Netherlands)

    Ubels, FL; Links, TP; Sluiter, WJ; Smit, AJ

    OBJECTIVE - Walking training (WT) is an established treatment for patients with intermittent claudication (IC). Abnormalities specific to diabetes, such as a relative preponderance of distal lesions and the contribution of microcirculatory disease, might well influence the results of WT. We compared

  3. Cooling tower modification for intermittent operation

    International Nuclear Information System (INIS)

    Midkiff, W.S.

    1975-03-01

    One of the cooling towers at Los Alamos Scientific Laboratory is being operated intermittently. The cooling tower has been modified to restrict air flow and to keep the tower from drying out. The modifications are relatively inexpensive, simple to operate, and have proved effective. (U.S.)

  4. Intermittent demand : Linking forecasting to inventory obsolescence

    NARCIS (Netherlands)

    Teunter, Ruud H.; Syntetos, Aris A.; Babai, M. Zied

    2011-01-01

    The standard method to forecast intermittent demand is that by Croston. This method is available in ERP-type solutions such as SAP and specialised forecasting software packages (e.g. Forecast Pro), and often applied in practice. It uses exponential smoothing to separately update the estimated demand

  5. Prevalence of intermittent preventive treatment with sulphadoxine ...

    African Journals Online (AJOL)

    Cite as: Orish VN, Onyeabor OS, Boampong JN , Afoakwah R, Nwaefuna E, Acquah S, et al. Prevalence of intermittent preventive treat- ment with sulphadoxine-pyrimethamine (IPTp-SP) use ..... by the increase of SP drug resistance in pregnant wom- en in Ghana since the adoption and implementation of. IPTp-SP policy35.

  6. Intermittent resistive faults in digital cmos circuits

    NARCIS (Netherlands)

    Kerkhoff, Hans G.; Ebrahimi, Hassan

    2015-01-01

    A major threat in extremely dependable high-end process node integrated systems in e.g. Avionics are no failures found (NFF). One category of NFFs is the intermittent resistive fault, often originating from bad (e.g. Via or TSV-based) interconnections. This paper will show the impact of these faults

  7. Tratamiento mediante terapia de presión negativa VAC® de herida infectada tras artrodesis raquídea Treatment of infected wound secondary to spinal arthrodesis with negative pressure therapy VAC®

    Directory of Open Access Journals (Sweden)

    V. Yuste Benavente

    2011-12-01

    Full Text Available Las complicaciones cutáneas secundarias a artrodesis raquídea son un problema frecuente que requiere la colaboración de los Servicios de Cirugía Plástica y en cuyo tratamiento la terapia de presión negativa puede resultar útil. En este artículo presentamos el caso de un paciente afectado por metástasis vertebrales de adenocarcinoma gástrico que requirió artrodesis raquídea y desarrolló posteriormente una úlcera por presión dorsal debido al material implantado. El sistema VAC® permitió la limpieza y disminución de tamaño de la lesión, siendo posible la cobertura posterior de la misma con un colgajo miocutáneo de dorsal ancho. En este artículo discutimos la utilidad de la terapia de presión negativa en este tipo de lesiones.Cutaneous complications secondary to spinal fusion are a common problem that requires the collaboration of the Department of Plastic Surgery and in which negative pressure therapy treatment may be useful. In this paper we present the case of a patient with spinal metastases secondary to gastric adenocarcinoma that required spinal fusion and developed a dorsal pressure ulcer secondary to the implanted material. VAC® therapy system allowed cleaning the wound and decreasing the size of the injury, thus making it possible subsequently to cover it with a latissimus dorsi myocutaneous flap. In this paper we discuss the usefulness of negative pressure therapy in this type of injury.

  8. 40 CFR 51.119 - Intermittent control systems.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Intermittent control systems. 51.119... Intermittent control systems. (a) The use of an intermittent control system (ICS) may be taken into account in... of any constant pollution control system which was in use before December 31, 1970, or the equivalent...

  9. Observations of different core water cluster ions Y-(H2O)n (Y = O2, HOx, NOx, COx) and magic number in atmospheric pressure negative corona discharge mass spectrometry.

    Science.gov (United States)

    Sekimoto, Kanako; Takayama, Mitsuo

    2011-01-01

    Reliable mass spectrometry data from large water clusters Y(-)(H(2)O)(n) with various negative core ions Y(-) such as O(2)(-), HO(-), HO(2)(-), NO(2)(-), NO(3)(-), NO(3)(-)(HNO(3))(2), CO(3)(-) and HCO(4)(-) have been obtained using atmospheric pressure negative corona discharge mass spectrometry. All the core Y(-) ions observed were ionic species that play a central role in tropospheric ion chemistry. These mass spectra exhibited discontinuities in ion peak intensity at certain size clusters Y(-)(H(2)O)(m) indicating specific thermochemical stability. Thus, Y(-)(H(2)O)(m) may correspond to the magic number or first hydrated shell in the cluster series Y(-)(H(2)O)(n). The high intensity discontinuity at HO(-)(H(2)O)(3) observed was the first mass spectrometric evidence for the specific stability of HO(-)(H(2)O)(3) as the first hydrated shell which Eigen postulated in 1964. The negative ion water clusters Y(-)(H(2)O)(n) observed in the mass spectra are most likely to be formed via core ion formation in the ambient discharge area (760 torr) and the growth of water clusters by adiabatic expansion in the vacuum region of the mass spectrometers (≈1 torr). The detailed mechanism of the formation of the different core water cluster ions Y(-)(H(2)O)(n) is described. Copyright © 2010 John Wiley & Sons, Ltd.

  10. Effects of flow intermittency and pharmaceutical exposure on the structure and metabolism of stream biofilms.

    Science.gov (United States)

    Corcoll, Natàlia; Casellas, Maria; Huerta, Belinda; Guasch, Helena; Acuña, Vicenç; Rodríguez-Mozaz, Sara; Serra-Compte, Albert; Barceló, Damià; Sabater, Sergi

    2015-01-15

    Increasing concentrations of pharmaceutical compounds occur in many rivers, but their environmental risk remains poorly studied in stream biofilms. Flow intermittency shapes the structure and functions of ecosystems, and may enhance their sensitivity to toxicants. This study evaluates the effects of a long-term exposure of biofilm communities to a mixture of pharmaceutical compounds at environmental concentrations on biofilm bioaccumulation capacity, the structure and metabolic processes of algae and bacteria communities, and how their potential effects were enhanced or not by the occurrence of flow intermittency. To assess the interaction between those two stressors, an experiment with artificial streams was performed. Stream biofilms were exposed to a mixture of pharmaceuticals, as well as to a short period of flow intermittency. Results indicate that biofilms were negatively affected by pharmaceuticals. The algal biomass and taxa richness decreased and unicellular green algae relatively increased. The structure of the bacterial (based on denaturing gradient gel electrophoresis of amplified 16S rRNA genes) changed and showed a reduction of the operational taxonomic units (OTUs) richness. Exposed biofilms showed higher rates of metabolic processes, such as primary production and community respiration, attributed to pharmaceuticals stimulated an increase of green algae and heterotrophs, respectively. Flow intermittency modulated the effects of chemicals on natural communities. The algal community became more sensitive to short-term exposure of pharmaceuticals (lower EC50 value) when exposed to water intermittency, indicating cumulative effects between the two assessed stressors. In contrast to algae, the bacterial community became less sensitive to short-term exposure of pharmaceuticals (higher EC50) when exposed to water intermittency, indicating co-tolerance phenomena. According to the observed effects, the environmental risk of pharmaceuticals in nature is high

  11. Intermittent Noise Induces Physiological Stress in a Coastal Marine Fish.

    Directory of Open Access Journals (Sweden)

    Tye A Nichols

    Full Text Available Anthropogenic noise in the ocean has increased substantially in recent decades, and motorized vessels produce what is likely the most common form of underwater noise pollution. Noise has the potential to induce physiological stress in marine fishes, which may have negative ecological consequences. In this study, physiological effects of increased noise (playback of boat noise recorded in the field on a coastal marine fish (the giant kelpfish, Heterostichus rostratus were investigated by measuring the stress responses (cortisol concentration of fish to increased noise of various temporal dynamics and noise levels. Giant kelpfish exhibited acute stress responses when exposed to intermittent noise, but not to continuous noise or control conditions (playback of recorded natural ambient sound. These results suggest that variability in the acoustic environment may be more important than the period of noise exposure for inducing stress in a marine fish, and provide information regarding noise levels at which physiological responses occur.

  12. Intermittent Noise Induces Physiological Stress in a Coastal Marine Fish.

    Science.gov (United States)

    Nichols, Tye A; Anderson, Todd W; Širović, Ana

    2015-01-01

    Anthropogenic noise in the ocean has increased substantially in recent decades, and motorized vessels produce what is likely the most common form of underwater noise pollution. Noise has the potential to induce physiological stress in marine fishes, which may have negative ecological consequences. In this study, physiological effects of increased noise (playback of boat noise recorded in the field) on a coastal marine fish (the giant kelpfish, Heterostichus rostratus) were investigated by measuring the stress responses (cortisol concentration) of fish to increased noise of various temporal dynamics and noise levels. Giant kelpfish exhibited acute stress responses when exposed to intermittent noise, but not to continuous noise or control conditions (playback of recorded natural ambient sound). These results suggest that variability in the acoustic environment may be more important than the period of noise exposure for inducing stress in a marine fish, and provide information regarding noise levels at which physiological responses occur.

  13. Edema pulmonar por pressão negativa após extubação traqueal: relato de caso Negative pressure pulmonary edema after tracheal extubation: case report

    Directory of Open Access Journals (Sweden)

    Fabiano Timbó Barbosa

    2007-03-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O edema pulmonar por pressão negativa após obstrução de via aérea é atualmente uma entidade bem descrita, porém pouco diagnosticada e com poucos casos relatados. O objetivo deste artigo foi relatar um caso de edema pulmonar por pressão negativa (EPPN após extubação traqueal com sucesso terapêutico, após uso de ventilação mecânica não-invasiva com pressão positiva. RELATO DO CASO: Paciente do sexo feminino, 22 anos, foi submetida à colecistectomia aberta. Os exames pré-operatórios encontravam-se sem alterações. Imediatamente após extubação a paciente apresentou dispnéia súbita e crepitações pulmonares. Foi iniciado tratamento para edema agudo de pulmão com oxigenoterapia sob máscara de Venturi, elevação do tórax e diurético. A paciente foi encaminhada a UTI devido a falha no tratamento. Ao chegar a UTI foi iniciada ventilação mecânica não-invasiva (VMNI com pressão de suporte (15 cmH2O e pressão expiratória final positiva (5 cmH2O com resolução dos sintomas. A paciente foi mantida em observação por mais 24 horas depois do evento com boas condições e recebeu alta para o quarto sem sintomas. CONCLUSÕES: O EPPN é uma entidade de difícil diagnóstico e deverá ser observada sempre que os pacientes evoluem com sinais e sintomas de insuficiência respiratória pós-extubação. Esta paciente se beneficiou de VMNI, mas caso haja falha terapêutica, a intubação traqueal e o suporte ventilatório mecânico invasivo deverão ser instituídos para melhor oxigenação dos pacientes.BACKGROUND AND OBJECTIVES: Negative pressure pulmonary edema after acute upper airway obstruction is a well-described event, thought infrequently diagnosed and reported. This report aimed at presenting a case of postextubation negative pressure pulmonary edema refractory to use of diuretics and with successful therapeutic after using positive pressure noninvasive mechanic ventilation. CASE REPORT: A

  14. Influence of drainage conditions on mucosal bladder damage by indwelling catheters. I. Pressure study.

    Science.gov (United States)

    Glahn, B E

    1988-01-01

    Clinical observations suggest the occurrence of a hydro-dynamically generated negative pressure wave in termination of bladder evacuation in patients with an intermittently clamped indwelling catheter. This in-vitro study confirmed the assumption. At circumstances like those of a bedridden person with a conventional urinary drainage system the transitory suction at the site of the catheter eyes reaches negative peak pressures of about 150-180 cm of water when catheters on a latex base are used and about 300-350 cm by catheters of 100% silicone, which is a less compliant (elastic) material. Catheters, drainage tubes and the combined function were analyzed regarding factors influencing this hydro-dynamical phenomenon, which may occur in some situations of straight drainage too. Clinical aspects are discussed. A noxious effect on the bladder mucosa is demonstrated in a subsequent study. It is concluded that the basal hydro-physical laws involved in bladder drainage by indwelling catheter need more attention.

  15. Research Report: Intermittent hypobaric hypoxia and hyperbaric oxygen on GAP-43 in the rat carotid body.

    Science.gov (United States)

    Peng, Zhengwu; Fan, Juan; Liu, Ling; Kuang, Fang; Xue, Fen; Wang, Bairen

    2015-01-01

    Adaptive changes in the carotid body (CB) including the expression of the growth-associated protein-43 (GAP-43) have been studied in response to low, but not high, oxygen exposure. Expression of GAP-43 in the CB of rats under different atmospheric pressures and oxygen partial pressure (PO2) conditions was investigated. Mature male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia (IHH, 0, 1, 2 and 3 weeks), intermittent hyperbaric oxygen (IHBO2, 0, 1, 5 and 10 days, sacrificed six hours or 24 hours after the last HBO2 exposure), and intermittent hyperbaric normoxia (IHN, same treatment pattern as IHBO2). GAP-43 was highly expressed (mainly in type I cells) in the CB of normal rats. IHH u-regulated GAP-43 expression in the CB with significant differences (immunohistochemical staining [IHC]: F(3,15)=40.64, P < 0.01; western blot [WB]: F(3,16) = 53.52, P < 0.01) across the subgroups. GAP-43 expression in the CB was inhibited by IHBO2 (controls vs. IHBO2 groups, IHC: F(6,30) = 15.85, P < 0.01; WB: F(6,29) = 15.95, P < 0.01). No detectable changes in GAP-43 expression were found for IHN. These findings indicated that different PO2 conditions, but not air pressures, played an important role in the plasticity of the CB, and that GAP-43 might be a viable factor for the plasticity of the CB.

  16. CONDITIONED ANALYSIS OF HIGH-LATITUDE SOLAR WIND INTERMITTENCY

    International Nuclear Information System (INIS)

    D'Amicis, R.; Consolini, G.; Bavassano, B.; Bruno, R.

    2012-01-01

    The solar wind is a turbulent medium displaying intermittency. Its intermittent features have been widely documented and studied, showing how the intermittent character is different in fast and slow wind. In this paper, a statistical conditioned analysis of the solar wind intermittency for a period of high-latitude fast solar wind is presented. In particular, the intermittent features are investigated as a function of the Alfvénic degree of fluctuations at a given scale. The results show that the main contribution to solar wind intermittency is due to non-Alfvénic structures, while Alfvénic increments are found to be characterized by a smaller level of intermittency than the previous ones. Furthermore, the lifetime statistics of Alfvénic periods are discussed in terms of a multiscale texture of randomly oriented flux tubes.

  17. Os efeitos da pressão positiva intermitente e do incentivador respiratório no pós-operatório de revascularização miocárdica The effects of intermittent positive pressure and incentive spirometry in the postoperative of myocardial revascularization

    Directory of Open Access Journals (Sweden)

    Walmir Romanini

    2007-08-01

    Full Text Available FUNDAMENTO: As complicações pulmonares são causas freqüentes do aumento de morbi-mortalidade nos pacientes submetidos à cirurgia cardíaca. A fisioterapia respiratória tem auxiliado na recuperação destes pacientes. OBJETIVO: Analisar o efeito fisioterapêutico da aplicação da pressão positiva intermitente (RPPI e do incentivador respiratório (IR em pacientes submetidos a cirurgia de revascularização do miocárdio. MÉTODOS: Quarenta pacientes foram divididos em dois grupos: um submetido à aplicação do RPPI (n=20 e o outro ao IR (n=20. Os pacientes foram avaliados nos momentos: pré-operatório, 24ª, 48ª e 72ª horas de pós-operatório, sendo aplicados os recursos no período pós-operatório. Analisaram-se os seguintes parâmetros: saturação de oxigênio (SpO2, freqüência respiratória (FR, volume minuto (VM, volume corrente (VC, pressão inspiratória máxima (Pi máx e pressão expiratória máxima (Pe máx. RESULTADOS: Nas variáveis demográficas e clínicas os grupos foram considerados homogêneos. No grupo submetido à aplicação com o RPPI identificou-se aumento da SpO2 na 48ª (p=0,007 e na 72ª horas (p=0,0001 quando comparado ao grupo IR. Nos parâmetros: FR, VM e VC na comparação entre os grupos não foram encontradas diferenças estatisticamente significativas. No grupo submetido ao IR a Pe máx na 24ª (p=0,02 e na 48ª (p=0,01 horas apresentaram um aumento significativo. CONCLUSÃO: Com o objetivo de reverter mais precocemente a hipoxemia, o RPPI mostrou-se mais eficiente em comparação ao IR; entretanto, para melhorar a força dos músculos respiratórios, o IR foi mais efetivo.BACKGROUND: Pulmonary complications are important causes of morbidity and fatalities among patients subject to cardiac surgery. The respiratory physiotherapy has been aiding in the recovery of these patient ones. OBJECTIVE: To evaluate the physiotherapeutic effect of intermittent positive pressure breathing (IPPB and incentive

  18. Spontaneous intermittent MRI changes of a pituitary stalk lesion causing diabetes insipidus and amenorrhea.

    Science.gov (United States)

    Curtò, Lorenzo; Trimarchi, Francesco; Cannavo, Salvatore

    2017-04-01

    Lymphocytic infundibulo-neurohypophysitis is a rare disorder. We report the case of a 29 year-old woman with diabetes insipidus and amenorrhea, in whom the magnetic resonance imaging demonstration of a pituitary stalk lesion was intermittent. We suggest that, in patients with endocrine dysfunction and positivity of circulating antipituitary antibodies at high title, magnetic resonance imaging should be repeated after few months, if negative.

  19. The impact of intermittent sources of energy on the market price of electricity

    International Nuclear Information System (INIS)

    Adigbli, Patrick; Mahuet, Audrey

    2013-01-01

    Parallel to liberalization of the electricity market, these past twenty years have been marked by a strong expansion of renewable energy in Europe. The increasing share of renewables in the energy mix - with a goal set by the European Commission at 20% by 2020 - has an impact on market prices. In the short run, subsidized intermittent energy may lead to lower prices or even to negative prices during certain periods of the year

  20. Insights from intermittent binocular rivalry and EEG

    Directory of Open Access Journals (Sweden)

    Michael A Pitts

    2011-09-01

    Full Text Available Novel stimulation and analytical approaches employed in EEG studies of ambiguous figures have recently been applied to binocular rivalry. The combination of intermittent stimulus presentation and EEG source imaging has begun to shed new light on the neural underpinnings of binocular rivalry. Here, we review the basics of the intermittent paradigm and highlight methodological issues important for interpreting previous results and designing future experiments. We then outline current analytical approaches, including EEG microstates, event-related potentials, and statistically-based source estimation, and propose a spatio-temporal model that integrates findings from several studies. Finally, we discuss the advantages and limitations of using binocular rivalry as a tool to investigate the neural basis of perceptual awareness.

  1. Intermittent character of interplanetary magnetic field fluctuations

    International Nuclear Information System (INIS)

    Bruno, Roberto; Carbone, Vincenzo; Chapman, Sandra; Hnat, Bogdan; Noullez, Alain; Sorriso-Valvo, Luca

    2007-01-01

    Interplanetary magnetic field magnitude fluctuations are notoriously more intermittent than velocity fluctuations in both fast and slow wind. This behavior has been interpreted in terms of the anomalous scaling observed in passive scalars in fully developed hydrodynamic turbulence. In this paper, the strong intermittent nature of the interplanetary magnetic field is briefly discussed comparing results performed during different phases of the solar cycle. The scaling properties of the interplanetary magnetic field magnitude show solar cycle variation that can be distinguished in the scaling exponents revealed by structure functions. The scaling exponents observed around the solar maximum coincide, within the errors, to those measured for passive scalars in hydrodynamic turbulence. However, it is also found that the values are not universal in the sense that the solar cycle variation may be reflected in dependence on the structure of the velocity field

  2. Intermittency exponent of the turbulent energy cascade

    International Nuclear Information System (INIS)

    Cleve, J.; Greiner, M.; Pearson, B.R.; Sreenivasan, K.R.

    2006-12-01

    We consider the turbulent energy dissipation from one-dimensional records in experiments using air and gaseous helium at cryogenic temperatures, and obtain the intermittency exponent via the two-point correlation function of the energy dissipation. The air data are obtained in a number of flows in a wind tunnel and the atmospheric boundary layer at a height of about 35 m above the ground. The helium data correspond to the centerline of a jet exhausting into a container. The air data on the intermittency exponent are consistent with each other and with a trend that increases with the Taylor microscale Reynolds number, R λ , of up to about 1000 and saturates thereafter. On the other hand, the helium data cluster around a constant value at nearly all R λ , this being about half of the asymptotic value for the air data. Some possible explanation is offered for this anomaly. (author)

  3. Optimal intermittent search strategies: smelling the prey

    International Nuclear Information System (INIS)

    Revelli, J A; Wio, H S; Rojo, F; Budde, C E

    2010-01-01

    We study the kinetics of the search of a single fixed target by a searcher/walker that performs an intermittent random walk, characterized by different states of motion. In addition, we assume that the walker has the ability to detect the scent left by the prey/target in its surroundings. Our results, in agreement with intuition, indicate that the prey's survival probability could be strongly reduced (increased) if the predator is attracted (or repelled) by the trace left by the prey. We have also found that, for a positive trace (the predator is guided towards the prey), increasing the inhomogeneity's size reduces the prey's survival probability, while the optimal value of α (the parameter that regulates intermittency) ceases to exist. The agreement between theory and numerical simulations is excellent.

  4. Downstream effects of intermittent power generation

    Energy Technology Data Exchange (ETDEWEB)

    Bretschko, G. (Austrian Academy of Sciences, Lunz (AT). Inst. fuer Limnologie); Moog, O. (Univ. Agric., Vienna (AT). Inst. Water Prov., Water Quality and Fisheries Management)

    1990-01-01

    Intermittent hydro-power generation creates frequent and dramatic discharge peaks combined with intervening extremely low water conditions downstream of the plant. Studies of the two Austrian rivers showed that whereas no alterations were found in the qualitative composition of zoobenthos, the decrease in abundance and biomass may amount up to 95%. The mismatch between the hydrography of surface water and groundwater might well be a cause of the detrimental effects of frequent and artificially created spates. The drastic reduction of zoobenthic biomass affects not only fish production but minimizes self-purification processes as well. Until tributaries diminish the effects of intermittent power generation, the river is reduced to a mere transport vehicle. (author).

  5. Intermittent preventive treatment of malaria in pregnancy

    DEFF Research Database (Denmark)

    Mbonye, A.K.; Bygbjerg, Ib Christian; Magnussen, Pascal

    2008-01-01

    OBJECTIVE: To assess whether traditional birth attendants, drug-shop vendors, community reproductive-health workers, or adolescent peer mobilizers could administer intermittent preventive treatment (IPTp) for malaria with sulfadoxine-pyrimethamine to pregnant women. METHODS: A non-randomized comm......OBJECTIVE: To assess whether traditional birth attendants, drug-shop vendors, community reproductive-health workers, or adolescent peer mobilizers could administer intermittent preventive treatment (IPTp) for malaria with sulfadoxine-pyrimethamine to pregnant women. METHODS: A non......, still births, and maternal and child deaths were secondary endpoints. FINDINGS: 1404 (67.5%) of 2081 with the new delivery system received two doses of sulfadoxine-pyrimethamine versus 281 (39.9%) of 704 with health units (P

  6. Lactic acidosis and diastolic hypotension after intermittent albuterol nebulization in a pediatric patient.

    Science.gov (United States)

    Saadia, Tehila A; George, Mathew; Lee, Haesoon

    2015-01-01

    We describe a case of 13-year-old female with intermittent asthma who developed lactic acidosis and diastolic hypotension after receiving intermittent albuterol nebulizer treatment. She presented to the emergency department (ED) with sudden onset of shortness of breath and chest pain. She received two albuterol nebulizer treatments at home without symptomatic relief. She was treated in the ED with intermittent albuterol nebulization for a total of 22.5 mg over the next 5 hours. A decrease in diastolic blood pressure from 60 mmHg to 40 mmHg was noted after the treatment. Blood lactate level was 5.9 mmol/L. She recovered from it and was discharged to home but she had recurrence of shortness of breath and presented to the ED two days later. She was treated with albuterol nebulization for a total of 17.5 mg over the next two and half hours and developed diastolic hypotension again, as low as 30 mm Hg. After discontinuation of albuterol nebulization, her BP normalized. Cardiopulmonary and metabolic side effects of continuous albuterol therapy have been reported in the recent medical literature. Our patient, however, developed these adverse effects on intermittent albuterol nebulizer treatment. It is important for the pediatrician to recognize the adverse effects of β2-agonist therapy to avoid carrying out extensive workup for hypotension and hyperlactatemia prolonging hospital stay.

  7. Lactic acidosis and diastolic hypotension after intermittent albuterol nebulization in a pediatric patient

    Directory of Open Access Journals (Sweden)

    Tehila A. Saadia

    2015-01-01

    Full Text Available We describe a case of 13-year-old female with intermittent asthma who developed lactic acidosis and diastolic hypotension after receiving intermittent albuterol nebulizer treatment. She presented to the emergency department (ED with sudden onset of shortness of breath and chest pain. She received two albuterol nebulizer treatments at home without symptomatic relief. She was treated in the ED with intermittent albuterol nebulization for a total of 22.5 mg over the next 5 hours. A decrease in diastolic blood pressure from 60 mmHg to 40 mmHg was noted after the treatment. Blood lactate level was 5.9 mmol/L. She recovered from it and was discharged to home but she had recurrence of shortness of breath and presented to the ED two days later. She was treated with albuterol nebulization for a total of 17.5 mg over the next two and half hours and developed diastolic hypotension again, as low as 30 mm Hg. After discontinuation of albuterol nebulization, her BP normalized. Cardiopulmonary and metabolic side effects of continuous albuterol therapy have been reported in the recent medical literature. Our patient, however, developed these adverse effects on intermittent albuterol nebulizer treatment. It is important for the pediatrician to recognize the adverse effects of β2-agonist therapy to avoid carrying out extensive workup for hypotension and hyperlactatemia prolonging hospital stay.

  8. Long-range forecasting of intermittent streamflow

    OpenAIRE

    F. F. van Ogtrop; R. W. Vervoort; G. Z. Heller; D. M. Stasinopoulos; R. A. Rigby

    2011-01-01

    Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a statistical model to forecast streamflow up to 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS) to determine th...

  9. Long-range forecasting of intermittent streamflow

    OpenAIRE

    F. F. van Ogtrop; R. W. Vervoort; G. Z. Heller; D. M. Stasinopoulos; R. A. Rigby

    2011-01-01

    Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a probabilistic statistical model to forecast streamflow 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS) to determine the probabil...

  10. Climate, intermittent humidification, and humidifier fever.

    OpenAIRE

    Anderson, K; Watt, A D; Sinclair, D; Lewis, C; McSharry, C P; Boyd, G

    1989-01-01

    Two summer outbreaks of humidifier fever (HF) are described in a microprocessor factory (factory A) and a printing factory (factory B). The air in each factory was humidified intermittently and controlled by present humidistats operating to maintain a relative humidity of 45% by an air handler incorporating a spray humidifier in factory A and two ceiling mounted spray humidifiers in factory B. Questionnaire data from each workforce suggested that although symptoms apparently occurred most com...

  11. AN ELDERLY WOMAN WITH INTERMITTENT CLAUDICATION

    Directory of Open Access Journals (Sweden)

    Nayyer Naveed Wazir

    2006-01-01

    Full Text Available This case report illustrates the misdiagnosis of intermittent claudication in an elderly with multiple cardiac risk factors. Careful clinical evaluation and imaging shifts the diagnosis from peripheral vascular disease to spinal stenosis. The decision whether to offer conservative therapy or proceed to spinal surgery requires an accurate assessment of the severity of the symptoms without ignoring the important role of patient preferences.

  12. Intermittent structures in atmospheric wind fields

    Energy Technology Data Exchange (ETDEWEB)

    Yueksek, Oersan; Muecke, Tanja; Peinke, Joachim [Wind Center for Wind Energy Research, University of Oldenburg (Germany)

    2011-07-01

    For design processes and load calculations of wind energy convertors (WEC) realistic synthetic wind fields are needed. The widely used norm is the standard IEC 61400. The IEC standard considers different simulation methods based on Gaussian statistics. However, the analysis of the measured wind fields by means of velocity increment statistics yields that these do not obey Gaussian statistics but are quite intermittent. The intermittent nature of atmospheric wind affects the whole chain of the wind energy conversion process and is assumed to be a major effect for additional loads and fatigue. A recently proposed method based on continuous time random walks (CTRWs) adequately reproduces the intermittency of turbulent atmospheric velocity increments on small time scales and provides wind fields with the desired high order two point statistics. In this work, we analyze highly time-resolved data sets measured in an extensive grid over the whole rotor plane of a WEC. The atmospheric wind fields are characterized statistically and the dependency of the higher order two point statistics on turbulence intensity, mean wind speed and height is shown. With this knowledge we are able to generate synthetic CTRW wind fields with the correct small scale structure.

  13. Pressure ulcers.

    Science.gov (United States)

    Reddy, Madhuri

    2011-04-28

    dressings, topical negative pressure, and topical phenytoin.

  14. Acute High-Intensity Intermittent Aerobic Exercise Reduces Plasma Angiopoietin-Like 2 in Patients With Coronary Artery Disease.

    Science.gov (United States)

    Larouche, Jean-François; Yu, Carol; Luo, Xiaoyan; Farhat, Nada; Guiraud, Thibaut; Lalongé, Julie; Gayda, Mathieu; Juneau, Martin; Lambert, Jean; Thorin-Trescases, Nathalie; Thorin, Eric; Nigam, Anil

    2015-10-01

    Circulating levels of angiopoietin-like 2 (ANGPTL2), a proinflammatory and proatherogenic protein, are elevated in patients with coronary artery disease (CAD). We hypothesized that high-intensity intermittent exercise (HIIE), known to be beneficial in patients with CAD, would reduce circulating ANGPTL2 levels. Plasma levels of ANGPTL2 were measured before and 20 minutes, 24 hours, and 72 hours after an acute exercise session in a crossover study comparing HIIE to moderate-intensity continuous exercise (MICE) in 14 patients with CAD and 20 age-matched and 20 young healthy controls. Pre-exercise ANGPTL2 levels were 3-fold higher in patients with CAD than in age-matched controls (P < 0.05) and correlated negatively with Vo2max/lean body mass (P < 0.0001). In healthy controls, ANGPTL2 levels were low and not affected by HIIE or MICE. In patients with CAD, ANGPTL2 levels decreased significantly by 41% after 20 minutes of HIIE, a reduction that was maintained after 24 and 72 hours (P < 0.05). In contrast, although ANGPTL2 levels decreased by 47% after 20 minutes of MICE, they increased by 104% after 24 hours and returned to baseline values after 72 hours (P < 0.05). A negative correlation was observed between this increase in ANGPTL2 levels and the mean rate-pressure product (heart rate × systolic blood pressure; index of myocardial O2 consumption) measured during MICE, suggesting that subclinical ischemia might promote ANGPTL2 expression. In patients with CAD, circulating ANGPTL2 levels are acutely reduced after HIIE and transiently increased after MICE. A sustained reduction in circulating ANGPTL2 levels could contribute to the chronic beneficial cardiometabolic effects of HIIE in patients with CAD. Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  15. NEGATIVE PRESSURE WOUND THERAPY (NPWT) FOR THE ...

    African Journals Online (AJOL)

    surgical approximation of the fascia, or alternatively by secondary healing through granulation and delayed ventral .... reduction in local bacterial loads (18), and mechanical tissue stress promoting angiogenesis and new tissue ... ''fistula VAC,'' a technique for management of enterocutaneous fistulae arising within the open.

  16. Negative Pressure Pulmonary Oedema Following Adenoidectomy ...

    African Journals Online (AJOL)

    threatening complication of laryngospasm that occurs during or after general anaesthesia. It is a complication of poorly treated or unrecognized laryngospasm occurring at extubation or later in the postoperative period. Objective: To emphasize ...

  17. Variations of Negative Pressure Wound Therapy

    African Journals Online (AJOL)

    of the commercially available VAC®, which uses a polyurethane foam sponge with a relatively coarse mesh. Evaluations of the efficacy of other types of dressing for diabetic foot ulcers need to be performed. With regard to this point, I read the article by Nain et al. who used originally designed devices, with great interest.

  18. NEGATIVE PRESSURE WOUND THERAPY (NPWT) FOR THE ...

    African Journals Online (AJOL)

    Laparostomy or the open abdomen can be a lifesaving intervention in surgical emergencies for abdominal compartment syndrome, ... been used to dress the open abdomen including intravenous fluidbags, Goretex, Bogota bags and ... series looked into the use of NPWT for laparostomy wound management with equipment ...

  19. The Effect of Intermittent Noise Stress on Ozone-Induced ...

    Science.gov (United States)

    Previous studies have established that acute exposure to air pollution increases the risk of cardiovascular dysfunction. Intrinsic factors are likely the most important determinants of how the body responds to an exposure. But data also suggests that non-environmental stressors like noise, which is a common urban public health problem, can modify and indeed worsen the response. Noise can cause obvious psychological disturbances typical of non-specific stress, but also changes that can increase the number of cardiovascular disease related mortalities. Therefore, we hypothesized that short-term exposure to noise would worsen the cardiovascular response to ozone. Male Wistar-Kyoto rats were implanted with radiotelemeters for the measurement of heart rate (HR), blood pressure (BP) and electrocardiogram (ECG) and exposed to intermittent noise (85-90 dB) for one week after which they were exposed to either ozone (0.8 ppm) or filtered air. Left ventricular functional responses to dobutamine were measured using a Millar probe as well as arrhythmic sensitivity to aconitine in a separate set of untelemetered rats 24 hours after exposure. HR and BP decreased in all telemetered animals during ozone exposure; noise caused BP and HR to increase. Baseline left ventricular pressure (LVP) was significantly higher in animals exposed to both noise and ozone when compared to no noise; furthermore those animals had the least amount of change in LVP, dP/dT max and min with increasi

  20. Middle Ear Pressure Regulation - Complementary Action of the Mastoid and Eustachian Tube

    DEFF Research Database (Denmark)

    Gaihede, Michael; Jacobsen, Henrik; Tveterås, Kjell

    , MEP counter-regulation presented as Eustachian tube openings with steep and fast pressure changes toward 0 Pa, whereas in others, gradual and slow pressure changes presented related to the mastoid; these changes sometimes crossed 0 Pa into opposite pressures. In many cases, combinations...... to continuous regulation of smaller pressures, whereas the tube was related to intermittent regulation of higher pressures....

  1. Connectivity analysis of suggestive brain areas involved in middle ear pressure regulation in humans

    DEFF Research Database (Denmark)

    SA, Sami; Gaihede, Michael

    2010-01-01

    , MEP counter-regulation presented as Eustachian tube openings with steep and fast pressure changes toward 0 Pa, whereas in others, gradual and slow pressure changes presented related to the mastoid; these changes sometimes crossed 0 Pa into opposite pressures. In many cases, combinations...... to continuous regulation of smaller pressures, whereas the tube was related to intermittent regulation of higher pressures....

  2. Middle Ear Pressure Regulation - Complementary Action of the Mastoid and Eustachian Tube

    DEFF Research Database (Denmark)

    Gaihede, Michael; Dirckx, Joris J J; Jacobsen, Henrik

    2010-01-01

    , MEP counter-regulation presented as Eustachian tube openings with steep and fast pressure changes toward 0 Pa, whereas in others, gradual and slow pressure changes presented related to the mastoid; these changes sometimes crossed 0 Pa into opposite pressures. In many cases, combinations...... to continuous regulation of smaller pressures, whereas the tube was related to intermittent regulation of higher pressures....

  3. Intermittent vibration protects aged muscle from mechanical and oxidative damage under prolonged compression.

    Science.gov (United States)

    Wong, Sing Wan; Cheung, Brian Chun Ho; Pang, Bruce Tak Keung; Kwong, Ateline; Chung, Anna; Lee, Kenneth Ka Ho; Mak, Arthur Fut Tak

    2017-04-11

    Deep tissue pressure ulcers, a serious clinical challenge originating in the muscle layer, are hardly detectable at the beginning. The challenge apparently occurs in aged subjects more frequently. As the ulcer propagates to the skin surface, it becomes very difficult to manage and can lead to fatal complications. Preventive measures are thus highly desirable. Although the complex pathological mechanisms have not been fully understood, prolonged and excessive physical challenges and oxidative stress are believed to be involved in the ulcer development. Previous reports have demonstrated that oxidative stress could compromise the mechanical properties of muscle cells, making them easier to be damaged when physical challenges are introduced. In this study, we used senescence accelerated (SAMP8) mice and its control breed (SAMR1) to examine the protective effects of intermittent vibration on aged and control muscle tissues during prolonged epidermal compression under 100mmHg for 6h. Results showed that an application of 35Hz, 0.25g intermittent vibration during compression decreased the compression-induced muscle breakdown in SAMP8 mice, as indicated histologically in terms of number of interstitial nuclei. The fact that no significant difference in muscle damage could be established in the corresponding groups in SAMR1 mice suggests that SAMR1 mice could better accommodate the compression insult than SAMP8 mice. Compression-induced oxidative damage was successfully curbed using intermittent vibration in SAMP8 mice, as indicated by 8-OHdG. A possible explanation is that the anti-oxidative defense could be maintained with intermittent vibration during compression. This was supported by the expression level of PGC-1-alpha, catalase, Gpx-1 and SOD1. Our data suggested intermittent vibration could serve as a preventive measure for deep tissue ulcer, particularly in aged subjects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Macroinvertebrate community responses to hydrological controls and groundwater abstraction effects across intermittent and perennial headwater streams.

    Science.gov (United States)

    White, James C; House, Andy; Punchard, Neil; Hannah, David M; Wilding, Nicholas A; Wood, Paul J

    2018-01-01

    Intermittent rivers comprise a significant proportion of river networks globally and their spatial extent is predicted to increase with rising water abstraction pressures. Despite this, the ecological implications of hydrological modifications within intermittent rivers have received limited research attention. This paper examines macroinvertebrate assemblages across intermittent and perennial sections of headwater streams within the Hampshire Avon catchment (United Kingdom) over a five-year period. The composition of faunal assemblages was quantified in relation to four hydrological metrics: the duration of flowing conditions, the geographical proximity to the nearest perennial source along each watercourse (two observed flow parameters) and two modelled groundwater abstraction influences. The results highlight that macroinvertebrate communities inhabiting sites which dry periodically and are positioned at greater distances (>c. 2.5km) above the perennial source (the most upstream point of permanent flow within a given year) possessed the highest conservation values. These sites supported species that are rare in many areas of Europe (e.g. Ephemeroptera: Paraletophlebia werneri) or with limited geographical distribution across the United Kingdom (e.g. Trichoptera: Limnephilus bipunctatus). A range of faunal community diversity indices were found to be more sensitive to the antecedent flow duration and distance from the perennial source, rather than any effects of groundwater abstraction. Taxonomic richness responded most strongly to these observed flow parameters and varied more markedly with the distance from the perennial source compared to the antecedent flow duration. Several taxa were significantly associated with the observed flow parameters, particularly those predominantly inhabiting perennially flowing systems. However, the distance that such fauna could migrate into intermittent reaches varied between taxa. This research demonstrates the overriding

  5. Ecoulements intermittents de gaz et de liquide en conduite verticale Intermittent Gas and Liquid Flows in a Vertical Pipe.

    Directory of Open Access Journals (Sweden)

    Line A.

    2006-11-01

    Full Text Available Le modèle présenté ici permet la pré-détermination du gradient de pression, du taux global de gaz, et de grandeurs caractéristiques de l'intermittence, dans un écoulement à poches et bouchons en conduite verticale. L'écriture des lois de conservation en moyenne phasique conditionnelle conduit à la définition d'une cellule moyenne équivalente. La fermeture du modèle est assurée par des lois de contrainte de cisaillement film-paroi, film-poche, bouchon-paroi, par une loi d'arrachage du gaz au culot de la poche, une loi de glissement du gaz dans les bouchons et par une loi de la vitesse moyenne de propagation des fronts de poches. Le calibrage et la qualification du modèle s'appuient sur deux banques de données, dont l'une a été obtenue avec des fluides pétroliers dans des conditions proches des situations industrielles (boucle diphasique de Boussens. The model described here can be used to predetermine the pressure gradient, the overall gas rate and the characteristic intermittence magnitudes in pocket and slug flow in a vertical pipe. The way governing equations in the conditional phase average are written defines an equivalent average cell. The model is closed by film/wall, film/pocket and slug/wall shear-stress laws, by a pulloff law for the gas at the bottom of the pocket, a slippage law for the gas in the slugs, and a mean propagation velocity law for the pocket fronts. The calibration and qualification of the model are based on two data banks, one of which contains data on petroleum fluids under conditions close to industrial situations (two-phase loop at Boussens.

  6. The experience of aggressive outbursts in Intermittent Explosive Disorder.

    Science.gov (United States)

    Kulper, Daniel A; Kleiman, Evan M; McCloskey, Michael S; Berman, Mitchell E; Coccaro, Emil F

    2015-02-28

    Conceptualizations of Intermittent Explosive Disorder (IED) have suffered from a scarcity of research investigating the subjective experience and phenomenology of the aggressive outbursts among those with IED relative to those who partake in more normative forms of aggression. Furthermore, though some studies have shown that individuals with IED are more impaired and have a poorer quality of life, few studies looked at negative outcomes specific to an individual with IED׳s aggressive behavior. The purpose of this study was to examine the subjective experience and social, occupational, and legal consequences of aggressive outbursts in IED. We assessed individuals with IED (n=410), psychiatric controls (n=133), and healthy controls (HC) (n=154) in the experiential correlates present before, during, and after an aggressive outburst as well as the consequences of aggressive outbursts. Results indicated that before and during aggressive outbursts, individuals with IED experienced more intense anger, physiological reactivity, and feelings of dyscontrol as well as more remorse after an aggressive outburst. Furthermore, individuals with IED report more negative consequences of their aggressive outbursts. These results provide an account of how the subjective experience and consequences of aggressive outbursts in IED differ from those with more normative forms of aggression. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Hovering and intermittent flight in birds

    International Nuclear Information System (INIS)

    Tobalske, Bret W

    2010-01-01

    Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound (∼0.3 kg) and small birds with rounded wings do not use intermittent glides.

  8. Hovering and intermittent flight in birds

    Energy Technology Data Exchange (ETDEWEB)

    Tobalske, Bret W, E-mail: bret.tobalske@mso.umt.ed [Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, Missoula, MT 59812 (United States)

    2010-12-15

    Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound ({approx}0.3 kg) and small birds with rounded wings do not use intermittent glides.

  9. Intermittent oral iron supplementation during pregnancy (Review)

    Science.gov (United States)

    Peña-Rosas, Juan Pablo; De-Regil, Luz Maria; Dowswell, Therese; Viteri, Fernando E

    2014-01-01

    Background Anaemia is a frequent condition during pregnancy, particularly among women from developing countries who have insufficient iron intake to meet increased iron needs of both the mother and the fetus. Traditionally, gestational anaemia has been prevented with the provision of daily iron supplements throughout pregnancy, but adherence to this regimen due to side effects, interrupted supply of the supplements, and concerns about safety among women with an adequate iron intake, have limited the use of this intervention. Intermittent (i.e. one, two or three times a week on non-consecutive days) supplementation with iron alone or in combination with folic acid or other vitamins and minerals has recently been proposed as an alternative to daily supplementation. Objectives To assess the benefits and harms of intermittent supplementation with iron alone or in combination with folic acid or other vitamins and minerals to pregnant women on neonatal and pregnancy outcomes. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (23 March 2012). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) for ongoing studies and contacted relevant organisations for the identification of ongoing and unpublished studies (23 March 2012). Selection criteria Randomised or quasi-randomised trials. Data collection and analysis We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy. Main results This review includes 21 trials from 13 different countries, but only 18 trials (with 4072 women) reported on our outcomes of interest and contributed data to the review. All of these studies compared daily versus intermittent iron supplementation. Three studies provided iron alone, 12 iron+folic acid and three more iron plus multiple vitamins and minerals. Their methodological quality was mixed

  10. A stochastic model for intermittent search strategies

    International Nuclear Information System (INIS)

    Benichou, O; Coppey, M; Moreau, M; Suet, P H; Voituriez, R

    2005-01-01

    It is often necessary, in scientific or everyday life problems, to find a randomly hidden target. What is then the optimal strategy to reach it as rapidly as possible? In this article, we develop a stochastic theory for intermittent search behaviours, which are often observed: the searcher alternates phases of intensive search and slow motion with fast displacements. The first results of this theory have already been announced recently. Here we provide a detailed presentation of the theory, as well as the full derivation of the results. Furthermore, we explicitly discuss the minimization of the time needed to find the target

  11. Renewable energies: the cost of intermittency

    International Nuclear Information System (INIS)

    Crassous, Renaud; Roques, Fabien

    2013-01-01

    The authors indicate the different adaptations which will be required for the electric system to cope with the intermittency of solar and wind energy production, and propose an approximate assessment of the associated costs. Different types of adaptation are addressed: secure production in case of absence of wind or sun (electricity imports, construction of additional power stations), use of more flexible production means (gas turbines), grid extensions (connection to offshore production sites, routing of production one part of the country to the other). They think that beyond a 20 per cent share for renewable energies, these costs could rapidly increase

  12. Game performance and intermittent hypoxic training

    OpenAIRE

    Hinckson, E A; Hamlin, M J; Wood, M R; Hopkins, W G

    2007-01-01

    Live high‐train low altitude exposure simulated by hypoxic devices may improve athletic performance. In this study, intermittent normobaric hypoxia was achieved with the GO2altitude® hypoxicator to determine its effects on sea level performance in rugby players. Ten players were randomly assigned to two groups. Players in each group received 14 sessions of either hypoxic (10–15% O2) or normoxic (21% O2) exposure at rest over 14 consecutive days in a single blind fashion. Various performance m...

  13. GENESIS OF INTERPLANETARY INTERMITTENT TURBULENCE: A CASE STUDY OF ROPE–ROPE MAGNETIC RECONNECTION

    Energy Technology Data Exchange (ETDEWEB)

    Chian, Abraham C.-L.; Loew, Murray H. [Department of Biomedical Engineering, George Washington University, Washington, DC 20052 (United States); Feng, Heng Q. [Institute of Space Physics, Luoyang Normal University, Luoyang (China); Hu, Qiang [Department of Space Science and CSPAR, University of Alabama in Huntsville, Huntsville, AL 35805 (United States); Miranda, Rodrigo A. [UnB-Gama Campus, and Plasma Physics Laboratory, Institute of Physics, University of Brasília (UnB), Brasília DF 70910-900 (Brazil); Muñoz, Pablo R. [Department of Physics and Astronomy, University of La Serena, Av. Juan Cisternas 1200, La Serena (Chile); Sibeck, David G. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Wu, De J., E-mail: abraham.chian@gmail.com [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2016-12-01

    In a recent paper, the relation between current sheet, magnetic reconnection, and turbulence at the leading edge of an interplanetary coronal mass ejection was studied. We report here the observation of magnetic reconnection at the interface region of two interplanetary magnetic flux ropes. The front and rear boundary layers of three interplanetary magnetic flux ropes are identified, and the structures of magnetic flux ropes are reconstructed by the Grad–Shafranov method. A quantitative analysis of the reconnection condition and the degree of intermittency reveals that rope–rope magnetic reconnection is the most likely site for genesis of interplanetary intermittency turbulence in this event. The dynamic pressure pulse resulting from this reconnection triggers the onset of a geomagnetic storm.

  14. Intermittent fasting and cardiovascular disease: current evidence and unresolved questions.

    Science.gov (United States)

    Tinsley, Grant M; Horne, Benjamin D

    2018-01-01

    Intermittent fasting has produced a variety of beneficial health effects in animal models, although high-quality research in humans has been limited. This special report examines current evidences for intermittent fasting in humans, discusses issues that require further examination, and recommends new research that can improve the knowledge base in this emerging research area. While potentially useful for health improvement, intermittent fasting requires further study prior to widespread implementation for health purposes. Randomized, longer-term studies are needed to determine whether using intermittent fasting as a lifestyle rather than a diet is feasible and beneficial for the health of some members of the human population.

  15. Pressure sores: an operant conditioning approach to prevention.

    Science.gov (United States)

    Malament, I R; Dunn, M E; Davis, R

    1975-04-01

    A training system for the prevention of pressure sores has been designed to teach the paralytic person to relieve pressure intermittently from his ischium while sitting in a wheelchair. The system automates the training of wheelchair pushups, and conditions the person into exercising, based upon modified avoidance learning procedures. Results indicate that the paralytic person can be trained to pushup intermittently and efficiently using this system, thus reducing the incidence of pressure sore formation. Further long-term study is needed to assess the effectiveness of the training system as a preventative program for pressure sores.

  16. A botanical compound, Padma 28, increases walking distance in stable intermittent claudication

    DEFF Research Database (Denmark)

    Drabaek, H; Mehlsen, J; Himmelstrup, H

    1993-01-01

    and by measurements of the pain-free and the maximal walking distance on a treadmill. The ankle pressure index (ankle systolic pressure/arm systolic pressure) was calculated. The group randomized to active treatment received two tablets bid containing 340 mg of a dried herbal mixture composed according to an ancient...... lamaistic preparation (Padma 28). After active treatments, administered over a period of four months in a double-blinded, randomized design, the patients allocated to this group attained a significant increase in the pain-free walking distance from 52 m (20-106) to 86 m (24-164; P ...Thirty-six patients with a median age of sixty-seven years and a median duration of intermittent claudication of five years were randomized to either active treatment with Padma 28 or placebo. The effect of treatment was quantified by measurements of systemic and peripheral systolic blood pressures...

  17. Adaptive intermittent control: A computational model explaining motor intermittency observed in human behavior.

    Science.gov (United States)

    Sakaguchi, Yutaka; Tanaka, Masato; Inoue, Yasuyuki

    2015-07-01

    It is a fundamental question how our brain performs a given motor task in a real-time fashion with the slow sensorimotor system. Computational theory proposed an influential idea of feed-forward control, but it has mainly treated the case that the movement is ballistic (such as reaching) because the motor commands should be calculated in advance of movement execution. As a possible mechanism for operating feed-forward control in continuous motor tasks (such as target tracking), we propose a control model called "adaptive intermittent control" or "segmented control," that brain adaptively divides the continuous time axis into discrete segments and executes feed-forward control in each segment. The idea of intermittent control has been proposed in the fields of control theory, biological modeling and nonlinear dynamical system. Compared with these previous models, the key of the proposed model is that the system speculatively determines the segmentation based on the future prediction and its uncertainty. The result of computer simulation showed that the proposed model realized faithful visuo-manual tracking with realistic sensorimotor delays and with less computational costs (i.e., with fewer number of segments). Furthermore, it replicated "motor intermittency", that is, intermittent discontinuities commonly observed in human movement trajectories. We discuss that the temporally segmented control is an inevitable strategy for brain which has to achieve a given task with small computational (or cognitive) cost, using a slow control system in an uncertain variable environment, and the motor intermittency is the side-effect of this strategy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Intermittent exotropia: facts, opinions, and unknowns.

    Science.gov (United States)

    Romanchuk, Kenneth G

    2011-01-01

    Intermittent exotropia (IXT) can be a controversial topic, often eliciting lively discussion. This lecture will discuss its definition, incidence, age of onset, presentation, natural variation, criteria for deterioration, goals of treatment, effectiveness of surgical treatment, types of surgical treatment, and unwanted effects of surgical treatment. Results from the scientific literature, opinions of respected colleagues, the opinion of the author, and the results of live polling of the audience during the John Pratt-Johnson lecture are presented. IXT is defined as an exotropia that is present intermittently predominantly for distance. Its incidence is about 1% and it usually has an onset before age 5. Patients often present because of concern regarding the appearance of the eye misalignment. There is natural variation in the control of IXT, the angle of IXT, and the amount of stereopsis. Criteria that denote deterioration are increasing frequency of IXT, progressively and consistently increasing angle of IXT, loss of binocular vision, and increasing concern regarding the patient's appearance and its effect on social interaction. Goals of treatment are to retain equal or nearly equal vision, to obtain acceptable cosmesis, and to retain binocular vision. The long-term success of surgical treatment is not well proven. Persistent postoperative overcorrection is an unwanted effect of surgical treatment. The inherent biologic variation that occurs when measuring the components of IXT makes it difficult to be dogmatic about IXT, particularly when trying to decide when deterioration is occurring.

  19. Chaos as an intermittently forced linear system.

    Science.gov (United States)

    Brunton, Steven L; Brunton, Bingni W; Proctor, Joshua L; Kaiser, Eurika; Kutz, J Nathan

    2017-05-30

    Understanding the interplay of order and disorder in chaos is a central challenge in modern quantitative science. Approximate linear representations of nonlinear dynamics have long been sought, driving considerable interest in Koopman theory. We present a universal, data-driven decomposition of chaos as an intermittently forced linear system. This work combines delay embedding and Koopman theory to decompose chaotic dynamics into a linear model in the leading delay coordinates with forcing by low-energy delay coordinates; this is called the Hankel alternative view of Koopman (HAVOK) analysis. This analysis is applied to the Lorenz system and real-world examples including Earth's magnetic field reversal and measles outbreaks. In each case, forcing statistics are non-Gaussian, with long tails corresponding to rare intermittent forcing that precedes switching and bursting phenomena. The forcing activity demarcates coherent phase space regions where the dynamics are approximately linear from those that are strongly nonlinear.The huge amount of data generated in fields like neuroscience or finance calls for effective strategies that mine data to reveal underlying dynamics. Here Brunton et al.develop a data-driven technique to analyze chaotic systems and predict their dynamics in terms of a forced linear model.

  20. Intermittency Statistics in the Expanding Solar Wind

    Science.gov (United States)

    Cuesta, M. E.; Parashar, T. N.; Matthaeus, W. H.

    2017-12-01

    The solar wind is observed to be turbulent. One of the open questions in solar wind research is how the turbulence evolves as the solar wind expands to great distances. Some studies have focused on evolution of the outer scale but not much has been done to understand how intermittency evolves in the expanding wind beyond 1 AU (see [1,2]). We use magnetic field data from Voyager I spacecraft from 1 to 10AU to study the evolution of statistics of magnetic discontinuities. We perform various statistical tests on these discontinuities and make connections to the physical processes occurring in the expanding wind.[1] Tsurutani, Bruce T., and Edward J. Smith. "Interplanetary discontinuities: Temporal variations and the radial gradient from 1 to 8.5 AU." Journal of Geophysical Research: Space Physics 84.A6 (1979): 2773-2787.[2] Greco, A., et al. "Evidence for nonlinear development of magnetohydrodynamic scale intermittency in the inner heliosphere." The Astrophysical Journal 749.2 (2012): 105.

  1. Fluorescence intermittency in single cadmium selenide nanocrystals

    Science.gov (United States)

    Nirmal, M.; Dabbousi, B. O.; Bawendi, M. G.; Macklin, J. J.; Trautman, J. K.; Harris, T. D.; Brus, L. E.

    1996-10-01

    SEMICONDUCTOR nanocrystals offer the opportunity to study the evolution of bulk materials properties as the size of a system increases from the molecular scale1,2. In addition, their strongly size-dependent optical properties render them attractive candidates as tunable light absorbers and emitters in optoelectronic devices such as light-emitting diodes3,4 and quantum-dot lasers5,6, and as optical probes of biological systems7. Here we show that light emission from single fluorescing nanocrystals of cadmium selenide under continuous excitation turns on and off intermittently with a characteristic timescale of about 0.5 seconds. This intermittency is not apparent from ensemble measurements on many nanocrystals. The dependence on excitation intensity and the change in on/off times when a passivating, high-bandgap shell of zinc sulphide encapsulates the nanocrystal8,9 suggests that the abrupt turning off of luminescence is caused by photo-ionization of the nanocrystal. Thus spectroscopic measurements on single nanocrystals can reveal hitherto unknown aspects of their photophysics.

  2. Impact of intermittent fasting on glucose homeostasis.

    Science.gov (United States)

    Varady, Krista A

    2016-07-01

    This article provides an overview of the most recent human trials that have examined the impact of intermittent fasting on glucose homeostasis. Our literature search retrieved one human trial of alternate day fasting, and three trials of Ramadan fasting published in the past 12 months. Current evidence suggests that 8 weeks of alternate day fasting that produces mild weight loss (4% from baseline) has no effect on glucose homeostasis. As for Ramadan fasting, decreases in fasting glucose, insulin, and insulin resistance have been noted after 4 weeks in healthy normal weight individuals with mild weight loss (1-2% from baseline). However, Ramadan fasting may have little impact on glucoregulatory parameters in women with polycystic ovarian syndrome who failed to observe weight loss. Whether intermittent fasting is an effective means of regulating glucose homeostasis remains unclear because of the scarcity of studies in this area. Large-scale, longer-term randomized controlled trials will be required before the use of fasting can be recommended for the prevention and treatment of metabolic diseases.

  3. Intermittent preventive treatment of malaria in pregnancy

    DEFF Research Database (Denmark)

    Mbonye, A.K.; Bygbjerg, Ib Christian; Magnussen, Pascal

    2008-01-01

    OBJECTIVE: To assess whether traditional birth attendants, drug-shop vendors, community reproductive-health workers, or adolescent peer mobilizers could administer intermittent preventive treatment (IPTp) for malaria with sulfadoxine-pyrimethamine to pregnant women. METHODS: A non-randomized comm......OBJECTIVE: To assess whether traditional birth attendants, drug-shop vendors, community reproductive-health workers, or adolescent peer mobilizers could administer intermittent preventive treatment (IPTp) for malaria with sulfadoxine-pyrimethamine to pregnant women. METHODS: A non......-randomized community trial was implemented in 21 community clusters (intervention) and four clusters where health units provided routine IPTp (control). The primary outcome measures were access and adherence to IPTp, number of malaria episodes, prevalence of anaemia, and birth weight. Numbers of live births, abortions......, still births, and maternal and child deaths were secondary endpoints. FINDINGS: 1404 (67.5%) of 2081 with the new delivery system received two doses of sulfadoxine-pyrimethamine versus 281 (39.9%) of 704 with health units (P malaria episodes decreased from 906 (49...

  4. Game performance and intermittent hypoxic training

    Science.gov (United States)

    Hinckson, E A; Hamlin, M J; Wood, M R; Hopkins, W G

    2007-01-01

    Live high‐train low altitude exposure simulated by hypoxic devices may improve athletic performance. In this study, intermittent normobaric hypoxia was achieved with the GO2altitude® hypoxicator to determine its effects on sea level performance in rugby players. Ten players were randomly assigned to two groups. Players in each group received 14 sessions of either hypoxic (10–15% O2) or normoxic (21% O2) exposure at rest over 14 consecutive days in a single blind fashion. Various performance measures were obtained consecutively in a single testing session pre‐ and post‐exposure. Effects of hypoxic exposure on maximum speed and sprint times were trivial (<1.0%) but unclear (90% likely range, ±5% to ±9%). In rugby simulation, hypoxic exposure produced impairments of peak power in two scrums (15%, ±8%; 9%, ±7%) and impairments of time in offensive sprints (7%, ±8%) and tackle sprints (11%, ±9%). Pending further research, rugby players would be unwise to use normobaric intermittent hypoxic exposure to prepare for games at sea level. PMID:17311807

  5. Fast confirmation of 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH) in urine by LC/MS/MS using negative atmospheric-pressure chemical ionisation (APCI).

    Science.gov (United States)

    Weinmann, W; Goerner, M; Vogt, S; Goerke, R; Pollak, S

    2001-09-15

    A fast method using automated solid-phase extraction (SPE) and short-column liquid-chromatography coupled to tandem mass-spectrometry (LC/MS/MS) with negative atmospheric-pressure chemical ionisation (APCI) has been developed for the confirmation of 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH) in urine samples. This highly specific method which combines chromatographic separation and MS/MS-analysis can be used for the confirmation of positive immunoassay results with a NIDA cut-off of 15ng/ml. The conjugates of THC-COOH were hydrolysed prior to SPE, and a standard SPE was performed using C18-SPE columns. No derivatisation of the extracts was needed as in GC/MS analysis, and the LC run-time was 6.5min by gradient elution with a retention time of 2.4min. Linearity of calibration was obtained in the range between 0 and 500ng/ml (correlation coefficient R(2)=0.998). Using linear regression (0-50ng/ml) the limit of detection (LOD) was 2.0ng/ml and the limit of quantitation (LOQ) was 5.1ng/ml; day-to-day reproducibility and precision were tested at 15 and 250ng/ml and were 13.4ng/ml+/-3.3% and 255.8ng/ml+/-4.5%, respectively.

  6. A pilot study exploring quality of life experienced by patients undergoing negative-pressure wound therapy as part of their wound care treatment compared to patients receiving standard wound care.

    Science.gov (United States)

    Ousey, Karen J; Milne, Jeanette; Cook, Leanne; Stephenson, John; Gillibrand, Warren

    2014-08-01

    The use of negative pressure wound therapy (NPWT) has been widely documented as a technique to help heal complex wounds. This article presents the findings of a preliminary study which aimed to explore quality of life (QoL) experienced by patients undergoing NPWT as part of their wound care treatment in comparison to that of patients with a wound using traditional (standard) wound care therapies. A quasi-experimental study was undertaken, with patients treated in wound care/vascular clinics with chronic/acute wounds. QoL impact was measured using the Cardiff Wound Impact Schedule and administered post-consent at timed intervals. Our results identified that there were no real differences in QoL scores recorded by patients over the 12-week period. Although there was no overall interaction between the therapies used for wound healing, NPWT did have an effect on social life: during the first 2 weeks of the application of therapy, patients in the NPWT group reported an increase in the social life domain. The authors conclude that true QoL can only be elicited if an accurate baseline is established or if data is collected over a long enough period to allow comparison of scores over time. © 2012 The Authors. International Wound Journal © 2012 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  7. Modes of exercise training for intermittent claudication.

    Science.gov (United States)

    Lauret, Gert Jan; Fakhry, Farzin; Fokkenrood, Hugo J P; Hunink, M G Myriam; Teijink, Joep A W; Spronk, Sandra

    2014-07-04

    According to international guidelines and literature, all patients with intermittent claudication should receive an initial treatment of cardiovascular risk modification, lifestyle coaching, and supervised exercise therapy. In most studies, supervised exercise therapy consists of treadmill or track walking. However, alternative modes of exercise therapy have been described and yielded similar results to walking. Therefore, the following question remains: Which exercise mode gives the most beneficial results? To assess the effects of different modes of supervised exercise therapy on the maximum walking distance (MWD) of patients with intermittent claudication. To assess the effects of different modes of supervised exercise therapy on pain-free walking distance (PFWD) and health-related quality of life scores (HR-QoL) of patients with intermittent claudication. The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Cochrane Peripheral Vascular Diseases Group Specialised Register (July 2013); CENTRAL (2013, Issue 6), in The Cochrane Lib rary; and clinical trials databases. The authors searched the MEDLINE (1946 to July 2013) and Embase (1973 to July 2013) databases and reviewed the reference lists of identified articles to detect other relevant citations. Randomised controlled trials of studies comparing alternative modes of exercise training or combinations of exercise modes with a control group of supervised walking exercise in patients with clinically determined intermittent claudication. The supervised walking programme needed to be supervised at least twice a week for a consecutive six weeks of training. Two authors independently selected studies, extracted data, and assessed the risk of bias for each study. Because of different treadmill test protocols to assess the maximum or pain-free walking distance, we converted all distances or walking times to total metabolic equivalents (METs) using the American College of Sports Medicine

  8. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

    Directory of Open Access Journals (Sweden)

    Lindsay B. Baker

    2015-07-01

    Full Text Available Intermittent sports (e.g., team sports are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h. Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1 potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2 the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3 what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports. Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before

  9. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance.

    Science.gov (United States)

    Baker, Lindsay B; Rollo, Ian; Stein, Kimberly W; Jeukendrup, Asker E

    2015-07-14

    Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1-2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30-60 g/h in the form of a 6%-7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a game

  10. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

    Science.gov (United States)

    Baker, Lindsay B.; Rollo, Ian; Stein, Kimberly W.; Jeukendrup, Asker E.

    2015-01-01

    Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a

  11. Bound by Children: Intermittent Cohabitation and Living Together Apart

    Science.gov (United States)

    Cross-Barnet, Caitlin; Cherlin, Andrew; Burton, Linda

    2011-01-01

    In this article, we examine variations in low-income mothers' patterns of intermittent cohabitation and the voluntary and involuntary nature of these unions. Intermittent cohabitation involves couples living together and separating in repeating cycles. Using Three-City Study ethnographic data, we identified 45 low-income mothers involved in these…

  12. Intermittent Testicular Torsion | Obi | Nigerian Journal of Clinical ...

    African Journals Online (AJOL)

    Methods: Clinical and demographic data of all patients treated for intermittent testicular torsion from January 2007 to June 2015 were prospectively collected in a pro forma and analyzed. A diagnosis of intermittent torsion was made on the basis of recurrent scrotal pain, presence of abnormal testicular lie in otherwise normal ...

  13. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intermittent mandatory ventilation attachment. 868.5955 Section 868.5955 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5955 Intermittent mandatory ventilation attachment. (a)...

  14. Water quality improvement of treated wastewater by intermittent soil percolation.

    Science.gov (United States)

    Castillo, G; Mena, M P; Dibarrart, F; Honeyman, G

    2001-01-01

    Our research aimed to evaluate intermittent soil infiltration of treated sewage for reuse in the north of Chile. Aerated lagoon effluent was infiltrated in columns packed with native soils (sandy-lime, lime-gravel and limey-sand). Columns were operated for more than a year under different cycles of filling and drying, depths and load pressures depending on soil characteristics. The efficiency of the system was determined through influent-effluent microbiological indicators level (faecal coliforms, E. coli, Salmonella spp, MS2 phage, and protozoan cysts), physicochemical characterisation (TOC, COD, BOD, nitrogen), and hydraulic flow measurement. Results showed: (a) high reduction of enteric bacteria (5-7 log10), some inactivation of phage (2-4 log10) and complete removal of intestinal cyst; (b) stable removal of organic matter (80-90% reduction of TOC, COD, BOD); and (c) partial ammonia reduction through adsorption and nitrification with denitrification mainly occurring in sandy soil. Preliminary data from pilot plant working in the field showed better results that those obtained in the laboratory especially removal of microbiological indicators. Microbiological quality of effluent met Class A regulations for agricultural reuse (WHO, 1989) and the system looks like an attractive alternative to cope with water shortage in the region.

  15. Modelling of intermittent microwave convective drying: parameter sensitivity

    Directory of Open Access Journals (Sweden)

    Zhang Zhijun

    2017-06-01

    Full Text Available The reliability of the predictions of a mathematical model is a prerequisite to its utilization. A multiphase porous media model of intermittent microwave convective drying is developed based on the literature. The model considers the liquid water, gas and solid matrix inside of food. The model is simulated by COMSOL software. Its sensitivity parameter is analysed by changing the parameter values by ±20%, with the exception of several parameters. The sensitivity analysis of the process of the microwave power level shows that each parameter: ambient temperature, effective gas diffusivity, and evaporation rate constant, has significant effects on the process. However, the surface mass, heat transfer coefficient, relative and intrinsic permeability of the gas, and capillary diffusivity of water do not have a considerable effect. The evaporation rate constant has minimal parameter sensitivity with a ±20% value change, until it is changed 10-fold. In all results, the temperature and vapour pressure curves show the same trends as the moisture content curve. However, the water saturation at the medium surface and in the centre show different results. Vapour transfer is the major mass transfer phenomenon that affects the drying process.

  16. Modelling of intermittent microwave convective drying: parameter sensitivity

    Science.gov (United States)

    Zhang, Zhijun; Qin, Wenchao; Shi, Bin; Gao, Jingxin; Zhang, Shiwei

    2017-06-01

    The reliability of the predictions of a mathematical model is a prerequisite to its utilization. A multiphase porous media model of intermittent microwave convective drying is developed based on the literature. The model considers the liquid water, gas and solid matrix inside of food. The model is simulated by COMSOL software. Its sensitivity parameter is analysed by changing the parameter values by ±20%, with the exception of several parameters. The sensitivity analysis of the process of the microwave power level shows that each parameter: ambient temperature, effective gas diffusivity, and evaporation rate constant, has significant effects on the process. However, the surface mass, heat transfer coefficient, relative and intrinsic permeability of the gas, and capillary diffusivity of water do not have a considerable effect. The evaporation rate constant has minimal parameter sensitivity with a ±20% value change, until it is changed 10-fold. In all results, the temperature and vapour pressure curves show the same trends as the moisture content curve. However, the water saturation at the medium surface and in the centre show different results. Vapour transfer is the major mass transfer phenomenon that affects the drying process.

  17. Pressure induced insulator–metal transition and giant negative piezoresistance in Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}Al{sub 0.04}O{sub 3} polycrystal

    Energy Technology Data Exchange (ETDEWEB)

    Arumugam, S., E-mail: sarumugam1963@yahoo.com [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirapalli 620024, Tamil Nadu (India); Thiyagarajan, R. [Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203 (China); Kalaiselvan, G.; Sivaprakash, P. [Centre for High Pressure Research, School of Physics, Bharathidasan University, Tiruchirapalli 620024, Tamil Nadu (India)

    2016-11-01

    The effect of external hydrostatic pressure (P) on the magnetization (M) and resistivity (ρ) properties of charge-orbital (CO) ordered-insulating phase-separated manganite Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}Al{sub 0.04}O{sub 3} system is reported here. At ambient P, CO ordering transition and spin-canting in the AFM are observed at 223 K and 55 K respectively in M(T) and ρ(T) measurements. Application of P increases simultaneously the magnitude of magnetization (M) and transition temperature, and weakens the CO ordering in M(T) measurements up to 0.98 GPa. During ρ(T) measurements, P induces an insulator–metallic transition (T{sub IM}) at 1.02 GPa, and further increase of P up to 2.84 GPa leads to increase of T{sub IM} (dT{sub IM}/dP =21.6 K/GPa). ρ at T{sub IM} is reduced about three orders of magnitude at 2.84 GPa, and leads to the giant negative piezoresistance (~98%). These results are analyzed separately in two temperature regions i.e., below and above T{sub IM} by power function equation and small polaronic hopping model respectively. It is understood from these analyses that the application of P suppresses the Jahn–Teller distortions, electron–electron and electron–magnon scattering factors, and induces the insulator–metal transition in Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}Al{sub 0.04}O{sub 3} system. - Highlights: • Application of P on Pr{sub 0.6}Ca{sub 0.4}Mn{sub 0.96}Al{sub 0.04}O{sub 3} reduces resistivity (ρ) remarkably at low-temperatures, and exhibits an insulator to metallic transition at 1.02 GPa. • The reduction in ρ by P is about three orders of magnitude at 2.84 GPa, leads to the giant negative piezoresistance about 98%. • The effect of the suppression of Jahn–Teller distortions, electron–electron and electron–magnon scattering under an applied P exhibits to the metal-Insulator transition. • The phase-separation in this system has been tuned by both internal and external perturbations.

  18. Acute intermittent porphyria: Diagnosis per chance

    Directory of Open Access Journals (Sweden)

    Soundravally R

    2008-10-01

    Full Text Available Objectives: To report a case of acute intermittent porphyria (AIP diagnosed by chance during routine investigations. Clinical Presentation and Intervention: A 21-year-old female presented with vague gastrointestinal symptoms. Upon admission, she was disoriented. Later she developed generalized seizures and was treated with phenytoin, but the condition worsened. Upon investigation, her liver function, renal function, blood sugar level and electrolytes were within normal limits. When kept for routine laboratory testing, the color change in urine prompted us to investigate for porphyria. It was positive for phorphobilinogen (PBG and urophorphyrin. Since AIP had been diagnosed, the initial treatment with phenytoin was discontinued with a favorable outcome. A screening test for PBG in urine by Ehrlich′s reagent was performed on the patient′s mother and was positive. Conclusion: A high degree of suspicion at the laboratory can also determine the diagnosis of AIP, which is often missed by the clinician.

  19. Intermittent hypoxia and cancer: Undesirable bed partners?

    Science.gov (United States)

    Almendros, Isaac; Gozal, David

    2017-08-14

    The deleterious effects of intermittent hypoxia (IH) on cancer biology have been primarily evaluated in the context of the aberrant circulation observed in solid tumors which results in recurrent intra-tumoral episodic hypoxia. From those studies, IH has been linked to an accelerated tumor progression, metastasis and resistance to therapies. More recently, the role of IH in cancer has also been studied in the context of obstructive sleep apnea (OSA), since IH is a hallmark characteristic of this condition. Such recent studies are undoubtedly adding more information regarding the role of IH on tumor malignancy. In terms of the IH patterns associated with OSA, this altered oxygenation paradigm has been recently proposed as a determinant factor in fostering cancer incidence and progression from both in vitro and in vivo experimental models. Here, we summarize all the available evidence to date linking IH effects on several types of cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Compensatory mechanisms activated with intermittent energy restriction

    DEFF Research Database (Denmark)

    Coutinho, Sílvia Ribeiro; Halset, Eline Holli; Gåsbakk, Sigrid

    2017-01-01

    Background & aims: Strong compensatory responses, with reduced resting metabolic rate (RMR), increased exercise efficiency (ExEff) and appetite, are activated when weight loss (WL) is achieved with continuous energy restriction (CER), which try to restore energy balance. Intermittent energy......: 39 ± 9 y) with obesity (BMI: 36 ± 4 kg/m2) were randomized to lose a similar weight with an IER (N = 18) or a CER (N = 17) diet over a 12 week period. Macronutrient composition and overall energy restriction (33% reduction) were similar between groups. Body weight/composition, RMR, fasting......) were measured before and after WL. Results: Changes in body weight (≈12.5% WL) and composition were similar in both groups. Fasting RQ and ExEff at 10 W increased in both groups. Losing weight, either by IER or CER dieting, did not induce significant changes in subjective appetite ratings. RMR...

  1. Secret Underlying Unexplained Abdominal Pain, Neurological Symptoms and Intermittent Hypertension: Acute Intermittent Porphyria

    Directory of Open Access Journals (Sweden)

    Komac Andac

    2017-06-01

    Full Text Available A 21-year-old female patient with abdominal pain, vomiting and constipation was admitted to the hospital with the possible diagnosis of diabetic ketoacidosis. Due to increased abdominal pain and constipation the patient underwent a surgery with the diagnosis of ileus. However, no pathological findings were found in the abdominal organs apart from serous fluid in the abdominal cavity. The patient became hypertensive, tachycardic and had an episode of seizures postoperatively. Neurological manifestations with unexplained abdominal pain indicated a diagnosis of acute intermittent porphyria (AIP. Acute intermittent porphyria diagnosis is based on elevated urinary δ-aminolevulinic acid (ALA and porphobilinogen (PBG levels as well as hydroxymethylbilane synthase (HMBS IVS13-2 A>G heterozygous mutation. Familial Mediterranean Fever (FMF gene mutations were not confirmed. Porphyria should be considered in the differential diagnosis of patients with recurrent abdominal pain, neurological symptoms and lack of FMF gene polymorphism.

  2. Cost effectiveness of intermittent screening followed by treatment versus intermittent preventive treatment during pregnancy in West Africa

    DEFF Research Database (Denmark)

    Fernandes, Silke; Sicuri, Elisa; Halimatou, Diawara

    2016-01-01

    Background: Emergence of high-grade sulfadoxine-pyrimethamine (SP) resistance in parts of Africa has led to growing concerns about the efficacy of intermittent preventive treatment of malaria during pregnancy (IPTp) with SP. The incremental cost-effectiveness of intermittent screening and treatme...

  3. Intermittent intravenous followed by intermittent oral 1 alpha(OH)D3 treatment of secondary hyperparathyroidism in uraemia

    DEFF Research Database (Denmark)

    Brandi, L; Daugaard, H; Egsmose, C

    1996-01-01

    OBJECTIVES: To examine whether intermittent oral 1 alpha(OH)D3 treatment of patients on haemodialysis with secondary hyperparathyroidism (HPT) was able to maintain the marked suppression of PTH, which previously had been induced by an intermittent intravenous administration of 1 alpha(OH)D3...

  4. Intermittent drinking, oxytocin and human health.

    Science.gov (United States)

    Pruimboom, L; Reheis, D

    2016-07-01

    Looking at a waterhole, it is surprising that so many animals share the same space without visible signs of anxiety or aggression. Although waterholes are the preferred feeding locations of large carnivores, waterholes are shared by all type of herbivores of all sizes and shapes, including elephants. Recent research shows that the homeostatic disturbances leading to the "thirst feeling" not only activate specific substances regulating water and mineral household, but also the "trust and love" hormone oxytocin, while decreasing the production of the typical stress hormone cortisol. People using drugs, seem to be in search for oxytocin, as evidenced in studies with individuals on drugs such as ecstasy and gamma-hydroxybyturate. Hot environment, drought and increased sweating also activate specific oxytocin-producing parts of the hypothalamus, just as breastfeeding does in mother and infant. Water homeostasis is the only allostatic system activating trust neuro-anatomy and we suggest that this is due to the fact that all animals depend on water, whereas food type is species specific. Our hypothesis; regulating drinking behaviour through intermittent bulk drinking could increase oxytocin signalling, recover human trust and increase health by down-regulation of stress axis activity and inflammatory activity of the immune system. Intermittent bulk drinking should be defined as water (including tea and coffee) drinking up to a feeling of satiety and regulated by a mild feeling of thirst. This would mean that people would not drink less quantity but less frequently and that's how all animals, but also human newborns behave. It is the latter group, which is probably the only group of humans with a normal fluid homeostasis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. [Intermittent Explosive Disorder: A Controversial Diagnosis].

    Science.gov (United States)

    Zapata, Juan Pablo; Palacio, Juan David

    2016-01-01

    Intermittent explosive disorder (IED) is aan externalizing externalising disorder characterized characterised by recurrent aggression episodes. Even though this disorder was described several decades ago, and it carries personal and social consequences, there is little in the medical scientific literature on this. bibliographic production about it is scanty. To perform a conceptualization conceptualisation of this disorder, through the review and bibliometric analysis of the available scientific articles. A search was performed in databases with the english English terms intermittent explosive disorder, impulse disorders control [MeSH], in combination with other terms. A bibliometric analysis in the GoPubMed® search engineer was also performed using all data obtained in the search. was also perfomed. IED prevalence ranges from 1.4% to 7%, it presents more frequently during middle adolescence, and with more noticeable repercussions in men males than in womenfemales. The psychopathological core of IED is the impulsive aggressive behaviour that presents in the form of «attacks» that occurs in response to a lower precipitating stimulus. Scientific publications about IED are few and relatively recent, and the vast majority is provided bycomes from the United States (56.56%), and headed by a single author. This fact highlights the need to replicate the findings described about the IED in order to demonstrate the validity and reliability of its diagnostic criteria. It is possible that doubts about the existence of a diagnosis lead have led to such a scant literature about the IED. Available studies about IED allow have allowed characterizing a group of subjects with episodes of impulsive aggression to be characterised, but this description requires replication in different latitudesneeds to be repeated in different areas. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  6. Squinting and photophobia in intermittent exotropia.

    Science.gov (United States)

    Oh, Baek-Lok; Suh, Soh-Youn; Choung, Ho-Kyung; Kim, Seong-Joon

    2014-05-01

    To report factors associated with preoperative squinting, defined as transient eye closure in bright light, and photophobia and the factors affecting improvement of these symptoms postoperatively in intermittent exotropia. In this retrospective study, patients (N = 99) were divided into groups according to the presence (n = 54) or absence (n = 45) of preoperative squinting and the presence (n = 64) or absence (n = 35) of photophobia. Clinical characteristics, including overaction or underaction of the oblique muscle and fundus intorsion and extorsion, were compared between the two groups. The squinting and photophobia groups were further categorized into two subgroups each according to postoperative improvement. The extended list of characteristics, including the duration from onset to surgery, postoperative angle of deviation, and fusion, was compared between the two subgroups. Preoperatively, 54 (54.5%) and 64 (64.6%) patients had squinting and photophobia, respectively. The coincidence of squinting and photophobia was marginally significant (p = 0.05). Postoperatively, squinting and photophobia disappeared in 64.8 and 59.4% of the patients, respectively. The photophobia group had a younger onset age of strabismus than the nonphotophobia group (39.3 vs. 56.4 months; p = 0.03). Good fusional status at the near range was more common in the nonsquinting group than in the squinting group (74.3 vs. 47.6%; p = 0.02). Superior oblique overaction was significantly more common in the squinting group than in the nonsquinting group (11.1 vs. 0%; p = 0.03). Early surgical correction and successful outcomes were associated with squinting improvement (p = 0.001 and p = 0.02, respectively). More than 50% of patients with intermittent exotropia had squinting or photophobia, and approximately 60% of symptomatic patients experienced improvement postoperatively. The onset of strabismus, near fusion, superior oblique overaction, and fundus intorsion were related to these symptoms

  7. Managing server clusters on intermittent power

    Directory of Open Access Journals (Sweden)

    Navin Sharma

    2015-12-01

    Full Text Available Reducing the energy footprint of data centers continues to receive significant attention due to both its financial and environmental impact. There are numerous methods that limit the impact of both factors, such as expanding the use of renewable energy or participating in automated demand-response programs. To take advantage of these methods, servers and applications must gracefully handle intermittent constraints in their power supply. In this paper, we propose blinking—metered transitions between a high-power active state and a low-power inactive state—as the primary abstraction for conforming to intermittent power constraints. We design Blink, an application-independent hardware–software platform for developing and evaluating blinking applications, and define multiple types of blinking policies. We then use Blink to design both a blinking version of memcached (BlinkCache and a multimedia cache (GreenCache to demonstrate how application characteristics affect the design of blink-aware distributed applications. Our results show that for BlinkCache, a load-proportional blinking policy combines the advantages of both activation and synchronous blinking for realistic Zipf-like popularity distributions and wind/solar power signals by achieving near optimal hit rates (within 15% of an activation policy, while also providing fairer access to the cache (within 2% of a synchronous policy for equally popular objects. In contrast, for GreenCache, due to multimedia workload patterns, we find that a staggered load proportional blinking policy with replication of the first chunk of each video reduces the buffering time at all power levels, as compared to activation or load-proportional blinking policies.

  8. Large scale integration of intermittent renewable energy sources in the Greek power sector

    International Nuclear Information System (INIS)

    Voumvoulakis, Emmanouil; Asimakopoulou, Georgia; Danchev, Svetoslav; Maniatis, George; Tsakanikas, Aggelos

    2012-01-01

    As a member of the European Union, Greece has committed to achieve ambitious targets for the penetration of renewable energy sources (RES) in gross electricity consumption by 2020. Large scale integration of RES requires a suitable mixture of compatible generation units, in order to deal with the intermittency of wind velocity and solar irradiation. The scope of this paper is to examine the impact of large scale integration of intermittent energy sources, required to meet the 2020 RES target, on the generation expansion plan, the fuel mix and the spinning reserve requirements of the Greek electricity system. We perform hourly simulation of the intermittent RES generation to estimate residual load curves on a monthly basis, which are then inputted in a WASP-IV model of the Greek power system. We find that the decarbonisation effort, with the rapid entry of RES and the abolishment of the grandfathering of CO 2 allowances, will radically transform the Greek electricity sector over the next 10 years, which has wide-reaching policy implications. - Highlights: ► Greece needs 8.8 to 9.3 GW additional RES installations by 2020. ► RES capacity credit varies between 12.2% and 15.3%, depending on interconnections. ► Without institutional changes, the reserve requirements will be more than double. ► New CCGT installed capacity will probably exceed the cost-efficient level. ► Competitive pressures should be introduced in segments other than day-ahead market.

  9. Dependence of intermittent density fluctuations on collisionality in TJ-K

    Energy Technology Data Exchange (ETDEWEB)

    Reuther, Kyle; Garland, Stephen; Ramisch, Mirko [Institut fuer Grenzflaechenverfahrenstechnikund Plasmatechnologie, Universitaet Stuttgart (Germany); Manz, Peter [Physik-Department E28, Technische Universitaet Muenchen, Garching (Germany)

    2016-07-01

    Particle and heat transport losses due to edge turbulence are well known phenomena commonly seen in toroidal magnetic confinement devices. Furthermore in the scrape-off layer (SOL), turbulent density fluctuations are often observed to be intermittent and dominate particle transport to the vessel walls. In the adiabatic limit (small collisionality), of the two-field Hasegawa-Wakatani model, simulated turbulent density fluctuations are observed to couple to potential fluctuations and exhibit Gaussian behavior. However, in the hydrodynamic limit (large collisionality) the density and potential decouple. As a result, the density becomes passively advected, evolves towards the vorticity, and exhibits intermittent behavior. The relationship between collisionality and intermittency is investigated experimentally at the stellarator TJ-K. To vary the plasma collisionality, which is related to electron density and temperature, parameters such as gas type, neutral gas pressure, magnetic field, and heating power are varied. Radial profiles of plasma density, temperature, floating potential, and vorticity are recorded via a scanning 7-tip Langmuir probe array. First results are presented.

  10. Amygdala hyperactivation to angry faces in intermittent explosive disorder.

    Science.gov (United States)

    McCloskey, Michael S; Phan, K Luan; Angstadt, Mike; Fettich, Karla C; Keedy, Sarah; Coccaro, Emil F

    2016-08-01

    Individuals with intermittent explosive disorder (IED) were previously found to exhibit amygdala hyperactivation and relatively reduced orbital medial prefrontal cortex (OMPFC) activation to angry faces while performing an implicit emotion information processing task during functional magnetic resonance imaging (fMRI). This study examines the neural substrates associated with explicit encoding of facial emotions among individuals with IED. Twenty unmedicated IED subjects and twenty healthy, matched comparison subjects (HC) underwent fMRI while viewing blocks of angry, happy, and neutral faces and identifying the emotional valence of each face (positive, negative or neutral). We compared amygdala and OMPFC reactivity to faces between IED and HC subjects. We also examined the relationship between amygdala/OMPFC activation and aggression severity. Compared to controls, the IED group exhibited greater amygdala response to angry (vs. neutral) facial expressions. In contrast, IED and control groups did not differ in OMPFC activation to angry faces. Across subjects amygdala activation to angry faces was correlated with number of prior aggressive acts. These findings extend previous evidence of amygdala dysfunction in response to the identification of an ecologically-valid social threat signal (processing angry faces) among individuals with IED, further substantiating a link between amygdala hyperactivity to social signals of direct threat and aggression. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Intermittent Brugada Syndrome Presenting with Syncope in an Adult Female

    Directory of Open Access Journals (Sweden)

    Patricia Chavez

    2014-01-01

    Full Text Available Background. Brugada syndrome accounts for 4–12% of all sudden deaths worldwide and at least 20% of sudden deaths in patients with structurally normal hearts. Case Report. A 48-year-old female presented to the emergency department after two witnessed syncopal episodes. While awaiting discharge had a third collapse followed by cardiac arrest with shockable rhythm. Initial electrocardiogram showed wide QRS complex with left axis deviation, ST-segment elevation of 2 mm followed by a negative T wave with no isoelectric separation, suggestive of spontaneous intermittent Brugada type 1 pattern. Cardiac magnetic resonance imaging demonstrated neither structural heart disease nor abnormal myocardium. After placement of an implantable cardioverter defibrillator the patient was discharged. Why should an emergency physician be aware of this? Brugada syndrome is an infrequently encountered clinical entity which may have a fatal outcome. This syndrome primarily presents with syncope. It should be considered as a component of differential diagnosis in patients with family history of syncope and sudden cardiac death.