WorldWideScience

Sample records for airway pressure influences

  1. Nasal continuous positive airway pressure

    DEFF Research Database (Denmark)

    Scholze, Alexandra; Lamwers, Stephanie; Tepel, Martin;

    2012-01-01

    Obstructive sleep apnoea (OSA) is linked to increased cardiovascular risk. This risk can be reduced by nasal continuous positive airway pressure (nCPAP) treatment. As OSA is associated with an increase of several vasoconstrictive factors, we investigated whether nCPAP influences the digital volum...

  2. Influence of upper body position on middle cerebral artery blood velocity during continuous positive airway pressure breathing

    DEFF Research Database (Denmark)

    Højlund Rasmussen, J; Mantoni, T; Belhage, B;

    2007-01-01

    in 11 healthy subjects during CPAP at different body positions (15 degrees head-down tilt, supine, 15 degrees, 30 degrees and 45 degrees upper body elevation). In the supine position, 10 cmH(2)O of CPAP reduced MCA V(mean) by 9 +/- 3% and increased cHbT by 4 +/- 2 micromol/L (mean +/- SEM); (P ....05). In the head-down position, CPAP increased cHbT to 13 +/- 2 micromol/L but left MCA V(mean) unchanged. Upper body elevation by 15 degrees attenuated the CPAP associated reduction in MCA V(mean) (-7 +/- 2%), while cHbT returned to baseline (1 +/- 2 micromol/L). With larger elevation of the upper body MCA V......Continuous positive airway pressure (CPAP) is a treatment modality for pulmonary oxygenation difficulties. CPAP impairs venous return to the heart and, in turn, affects cerebral blood flow (CBF) and augments cerebral blood volume (CBV). We considered that during CPAP, elevation of the upper body...

  3. Genioglossus muscle responses to upper airway pressure changes: afferent pathways.

    Science.gov (United States)

    Mathew, O P; Abu-Osba, Y K; Thach, B T

    1982-02-01

    The afferent pathway of an upper airway reflex in which genioglossus muscle electromyographic (GG EMG) activity is influenced by pharyngeal pressure changes was investigated in 20 anesthetized rabbits. We took advantage of the fact that the upper airway was separated into two compartments by pharyngeal closure occurring when the animals breathe through a tracheostomy. This allowed pressure to be delivered selectively either to the nose and nasopharynx or to the larynx and hypopharynx. Midcervical vagotomy did not eliminate the GG EMG response to pressure stimuli. On the other hand high cervical vagotomy or superior laryngeal nerve section eliminated the response in the laryngeal compartment, but not in the nasopharyngeal compartment. Topical anesthesia of the mucosa of the nose, pharynx, and larynx abolished the response in both compartments. Therefore we conclude that more than one afferent pathway exists for this upper airway pressure reflex; the primary afferent pathway from the laryngeal compartment is the superior laryngeal branch of the vagus nerve, whereas the primary afferent pathway for the nasopharynx is nonvagal. Trigeminal nerve, glossopharyngeal nerve, and/or nervus intermedius carry nonvagal afferents from the nasopharynx and nose. The topical anesthetic and nerve section studies suggest that superficial receptors mediate this response. The occurrence of swallowing in response to upper airway pressure changes and its elimination by topical anesthesia or superior mechanoreceptors may mediate both genioglossus respiratory responses and swallowing responses.

  4. Continuous positive airway pressure therapy: new generations.

    LENUS (Irish Health Repository)

    Garvey, John F

    2012-02-01

    Continuous positive airway pressure (CPAP) is the treatment of choice for obstructive sleep apnoea syndrome (OSAS). However, CPAP is not tolerated by all patients with OSAS and alternative modes of pressure delivery have been developed to overcome pressure intolerance, thereby improving patient comfort and adherence. Auto-adjustable positive airway pressure (APAP) devices may be utilised for the long-term management of OSAS and may also assist in the initial diagnosis of OSAS and titration of conventional CPAP therapy. Newer modalities such as C-Flex and A-Flex also show promise as treatment options in the future. However, the evidence supporting the use of these alternative modalities remains scant, in particular with regard to long-term cardiovascular outcomes. In addition, not all APAP devices use the same technological algorithms and data supporting individual APAP devices cannot be extrapolated to support all. Further studies are required to validate the roles of APAP, C-Flex and A-Flex. In the interim, standard CPAP therapy should continue as the mainstay of OSAS management.

  5. Continuous positive airway pressure therapy: new generations.

    LENUS (Irish Health Repository)

    Garvey, John F

    2010-02-01

    Continuous positive airway pressure (CPAP) is the treatment of choice for obstructive sleep apnoea syndrome (OSAS). However, CPAP is not tolerated by all patients with OSAS and alternative modes of pressure delivery have been developed to overcome pressure intolerance, thereby improving patient comfort and adherence. Auto-adjustable positive airway pressure (APAP) devices may be utilised for the long-term management of OSAS and may also assist in the initial diagnosis of OSAS and titration of conventional CPAP therapy. Newer modalities such as C-Flex and A-Flex also show promise as treatment options in the future. However, the evidence supporting the use of these alternative modalities remains scant, in particular with regard to long-term cardiovascular outcomes. In addition, not all APAP devices use the same technological algorithms and data supporting individual APAP devices cannot be extrapolated to support all. Further studies are required to validate the roles of APAP, C-Flex and A-Flex. In the interim, standard CPAP therapy should continue as the mainstay of OSAS management.

  6. Walking with continuous positive airway pressure

    NARCIS (Netherlands)

    Dieperink, W.; Goorhuis, JF; de Weerd, W; Hazenberg, A; Zijistra, JG; Nijsten, MWN

    2006-01-01

    A ventilator-dependent child had been in the paediatric intensive care unit (PICU) ever since birth. As a result, she had fallen behind considerably in her development. After 18 months, continuous positive airway tracheostomy tube with a novel lightweight device device, the child was discharged home

  7. Multiple applications of the Boussignac continuous positive airway pressure system

    NARCIS (Netherlands)

    Dieperink, Willem

    2008-01-01

    Continuous positive airway pressure, (CPAP) is a form of treatment to support patients with dyspnea. For the application of CPAP a mechanical ventilator or complex CPAP apparatus is mostly used. The Boussignac CPAP (BCPAP) system developed by George Boussignac does not need such apparatus. The BCPAP

  8. Selective indication for positive airway pressure (PAP in sleep-related breathing disorders with obstruction

    Directory of Open Access Journals (Sweden)

    Stasche, Norbert

    2006-10-01

    Full Text Available Positive airway pressure (PAP is the therapy of choice for most sleep-related breathing disorders (SRBD. A variety of PAP devices using positive airway pressure (CPAP, BiPAP, APAP, ASV must be carefully considered before application. This overview aims to provide criteria for choosing the optimal PAP device according to severity and type of sleep-related breathing disorder. In addition, the range of therapeutic applications, constraints and side effects as well as alternative methods to PAP will be discussed. This review is based on an analysis of current literature and clinical experience. The data is presented from an ENT-sleep-laboratory perspective and is designed to help the ENT practitioner initiate treatment and provide support. Different titration methods, current devices and possible applications will be described. In addition to constant pressure devices (CPAP, most commonly used for symptomatic obstructive sleep apnoea (OSA without complicating conditions, BiPAP models will be introduced. These allow two different positive pressure settings and are thus especially suitable for patients with cardiopulmonary diseases or patients with pressure intolerance, increasing compliance in this subgroup considerably. Compliance can also be increased in patients during first night of therapy, patients with highly variable pressure demands or position-dependent OSA, by using self-regulating Auto-adjust PAP devices (Automatic positive airway pressure, APAP. Patients with Cheyne-Stokes breathing, a subtype of central sleep apnoea, benefit from adaptive servo-ventilation (ASV, which analyzes breathing patterns continually and adjusts the actual ventilation pressure accordingly. This not only reduces daytime sleepiness, but can also influence heart disease positively. Therapy with positive airway pressure is very effective in eliminating obstruction-related sleep diseases and symptoms. However, because therapy is generally applied for life, the optimal

  9. Continuous Positive Airway Pressure Strategies with Bubble Nasal Continuous Positive Airway Pressure: Not All Bubbling Is the Same: The Seattle Positive Airway Pressure System.

    Science.gov (United States)

    Welty, Stephen E

    2016-12-01

    Premature neonates are predisposed to complications, including bronchopulmonary dysplasia (BPD). BPD is associated with long-term pulmonary and neurodevelopmental consequences. Noninvasive respiratory support with nasal continuous positive airway pressure (CPAP) has been recommended strongly by the American Academy of Pediatrics. However, CPAP implementation has shown at least a 50% failure rate. Enhancing nasal CPAP effectiveness may decrease the need for mechanical ventilation and reduce the incidence of BPD. Bubble nasal CPAP is better than nasal CPAP using mechanical devices and the bubbling provides air exchange in distal respiratory units. The Seattle PAP system reduces parameters that assess work of breathing.

  10. Comparison of Efficacy and Tolerance of Automatic Continuous Positive Airway Pressure Devices With the Optimum Continuous Positive Airway Pressure.

    Science.gov (United States)

    Tommi, George; Aronow, Wilbert S; Sheehan, John C; McCleay, Matthew T; Meyers, Patrick G

    Patients diagnosed with obstructive sleep apnea syndrome were randomly placed on automatic continuous positive airway pressure (ACPAP) for 2 hours followed by manual titration for the rest of the night. One hundred sixty-one patients entered the study, with at least 50 patients titrated with each of 3 ACPAP devices. The optimum continuous positive airway pressure (CPAP) was defined as the lowest pressure with an apnea-hypoxia index of ≤5/hr, which ranged from 4 cm to 18 cm. Success with ACPAP was approximately 60%-80% when the optimum CPAP was 4-6 cm but fell to below 30% if the optimum CPAP was ≥8 cm (P = 0.001). Average ACPAP ranged from 2 to 10 cm below the optimum level if the optimum CPAP was ≥8 cm. Patients who responded to a low CPAP but deteriorated on higher pressures failed to respond to any of the automatic devices. We recommend that CPAP titration be performed manually before initiation of ACPAP in patients with obstructive sleep apnea. The basal pressure for ACPAP should be the optimum pressure obtained by manual titration. Limits on the upper level of ACPAP may be necessary for patients who deteriorate on higher positive pressures.

  11. Validation of airway resistance models for predicting pressure loss through anatomically realistic conducting airway replicas of adults and children.

    Science.gov (United States)

    Borojeni, Azadeh A T; Noga, Michelle L; Martin, Andrew R; Finlay, Warren H

    2015-07-16

    This work describes in vitro measurement of the total pressure loss at varying flow rate through anatomically realistic conducting airway replicas of 10 children, 4 to 8 years old, and 5 adults. Experimental results were compared with analytical predictions made using published airway resistance models. For the adult replicas, the model proposed by van Ertbruggen et al. (2005. J. Appl. Physiol. 98, 970-980) most accurately predicted central conducting airway resistance for inspiratory flow rates ranging from 15 to 90 L/min. Models proposed by Pedley et al. (1970. J. Respir. Physiol. 9, 371-386) and by Katz et al. (2011. J. Biomech. 44, 1137-1143) also provided reasonable estimates, but with a tendency to over predict measured pressure loss for both models. For child replicas, the Pedley and Katz models both provided good estimation of measured pressure loss at flow rates representative of resting tidal breathing, but under predicted measured values at high inspiratory flow rate (60 L/min). The van Ertbruggen model, developed based on flow simulations performed in an adult airway model, tended to under predict measured pressure loss through the child replicas across the range of flow rates studied (2 to 60 L/min). These results are intended to provide guidance for selection of analytical pressure loss models for use in predicting airway resistance and ventilation distribution in adults and children.

  12. Cromoglycate and Nedocromil: Influence on Airway Reactivity

    Science.gov (United States)

    Valletta, E. A.

    1994-01-01

    Although basic mechanisms of bronchial hyper-responsiveness (BHR) are still incompletely understood, inflammation of airways is likely to play a fundamental role in modulating BHR in patients with asthma. The involvement of several inflammatory cells (eosinophils, mast cells, lymphocytes, neutrophils, macrophages and platelets) and of bioactive mediators secreted by these cells in the pathogenesis of asthma is well documented. Sodium cromoglycate and nedocromil sodium are two pharmacological agents which have anti-allergic and anti-inflammatory properties. Their clinical effectiveness in mild to moderate asthma, and the capacity to reduce BHR under different natural and experimental conditions, make them valuable drugs for maintenance therapy in patients with asthma. PMID:18475597

  13. Early nasal continuous positive airway pressure in a cohort of the smallest infants in Denmark

    DEFF Research Database (Denmark)

    Hansen, Bo M; Esbjørn, Barbara Hoff; Greisen, G

    2004-01-01

    To evaluate neurodevelopmental outcome at age 5 y of age in a cohort of preterm children treated mainly with nasal continuous positive airway pressure (CPAP) in the neonatal period.......To evaluate neurodevelopmental outcome at age 5 y of age in a cohort of preterm children treated mainly with nasal continuous positive airway pressure (CPAP) in the neonatal period....

  14. Influence of Head and Neck Position on Oropharyngeal Leak Pressure and Cuff Position with the ProSeal Laryngeal Mask Airway and the I-Gel: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar Mishra

    2015-01-01

    Full Text Available Background. This study was designed to assess and compare the effect of head and neck position on the oropharyngeal leak pressures and cuff position (employing fibreoptic view of the glottis and ventilation scores between ProSeal LMA and the I-gel. Material and Methods. After induction of anesthesia, the supraglottic device was inserted and ventilation confirmed. The position of the head was randomly changed from neutral to flexion, extension, and lateral rotation (left. The oropharyngeal leak pressures, fibreoptic view of glottis, ventilation scores, and delivered tidal volumes and end tidal CO2 were noted in all positions. Results. In both groups compared with neutral position, oropharyngeal leak pressures were significantly higher with flexion and lower with extension but similar with rotation of head and neck. However the oropharyngeal leak pressure was significantly higher for ProSeal LMA compared with the I-gel in all positions. Peak airway pressures were significantly higher with flexion in both groups (however this did not affect ventilation, lower with extension in ProSeal group, and comparable in I-gel group but did not change significantly with rotation of head and neck in both groups. Conclusion. Effective ventilation can be done with both ProSeal LMA and I-gel with head in all the above positions. ProSeal LMA has a better margin of safety than I-gel due to better sealing pressures except in flexion where the increase in airway pressure is more with the former. Extreme precaution should be taken in flexion position in ProSeal LMA.

  15. Comparative evaluation of intraocular pressure changes subsequent to insertion of laryngeal mask airway and endotracheal tube.

    Directory of Open Access Journals (Sweden)

    Ghai B

    2001-07-01

    Full Text Available AIMS: To evaluate the intraocular pressure and haemodynamic changes subsequent to insertion of laryngeal mask airway and endotracheal tube. SUBJECTS AND METHODS: The study was conducted in 50 adult patients. A standard general anaesthesia was administered to all the patients. After 3 minutes of induction of anaesthesia baseline measurements of heart rate, non-invasive blood pressure and intraocular pressure were taken following which patients were divided into two groups: laryngeal mask airway was inserted in group 1 and tracheal tube in group 2. These measurements were repeated at 15-30 second, every minute thereafter up to 5 minutes after airway instrumentation. RESULTS: A statistically significant rise in heart rate, systolic blood pressure, diastolic blood pressure and intraocular pressure was seen in both the groups subsequent to insertion of laryngeal mask airway or endotracheal tube. Mean maximum increase was statistically more after endotracheal intubation than after laryngeal mask airway insertion. The duration of statistically significant pressure responses was also longer after endotracheal intubation. CONCLUSION: Laryngeal mask airway is an acceptable alternative technique for ocular surgeries, offering advantages in terms of intraocular pressure and cardiovascular stability compared to tracheal intubation.

  16. Randomized trial of prongs or mask for nasal continuous positive airway pressure in preterm infants.

    LENUS (Irish Health Repository)

    Kieran, Emily A

    2012-11-01

    To determine whether nasal continuous positive airway pressure (NCPAP) given with nasal prongs compared with nasal mask reduces the rate of intubation and mechanical ventilation in preterm infants within 72 hours of starting therapy.

  17. 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.

  18. Effects of Altered Intra-abdominal Pressure on the Upper Airway Collapsibility in a Porcine Model

    Institute of Scientific and Technical Information of China (English)

    Shu-Lin Ren; Yan-Ru Li; Ji-Xiang Wu; Jing-Ying Ye; Rachel Jen

    2015-01-01

    Background: Obstructive sleep apnea is strongly associated with obesity, particularly abdominal obesity common in centrally obese males.Previous studies have demonstrated that intra-abdominal pressure (IAP) is increased in morbid obesity, and tracheal traction forces may influence pharyngeal airway collapsibility.This study aimed to investigate that whether IAP plays a role in the mechanism of upper airway (UA) collapsibility via IAP-related caudal tracheal traction.Methods: An abdominal wall lifting (AWL) system and graded CO2 pneumoperitoneum pressure was applied to four supine, anesthetized Guizhou miniature pigs and its effects on tracheal displacement (TD) and airflow dynamics of UA were studied.Individual run data in 3 min obtained before and after AWL and obtained before and after graded pneumoperitoneum pressure were analyzed.Differences between baseline and AWL/graded pneumoperitoneum pressure data of each pig were examined using a Student's t-test or analysis of variance.Results: Application of AWL resulted in decreased IAP and significant caudal TD.The average displacement amplitude was 0.44 mm (P < 0.001).There were three subjects showed increased tidal volume (TV) (P < 0.0l) and peak inspiratory airflow (P < 0.01);however, the change of flow limitation inspiratory UA resistance (Rua) was not significant.Experimental increased IAP by pneumoperitoneum resulted in significant cranial TD.The average displacement amplitude was 1.07 mm (P < 0.001) when IAP was 25 cmH20 compared to baseline.There were three subjects showed reduced Rua while the TV increased (P < 0.01).There was one subject had decreased TV and elevated Rua (P < 0.001).Conclusions: Decreased IAP significantly increased caudal TD, and elevated IAP significantly increased cranial TD.However, the mechanism of UA collapsibility appears primarily mediated by changes in lung volume rather than tracheal traction effect.TV plays an independent role in the mechanism of UA collapsibility.

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

    OpenAIRE

    2013-01-01

    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...

  20. Influence of Nasal Continues Positive Airway Pressure on Retention of Carbon Dioxide in Newborn%新生儿经鼻持续气管正压通气对二氧化碳潴留的影响

    Institute of Scientific and Technical Information of China (English)

    吴玫; 陈大鹏; 熊英; 陈超

    2012-01-01

    Objective To investigate the influence of nasal continues positive airway pressure (nCPAP) on retention of carbon dioxide(CO2) in newborns.Methods From June to December 2009,a total of 46 newborns who had nCPAP treatment for 72 hours in West China Second University Hospital,Sichuan University were included in nCPAP group.Meanwhile,another 20 cases of neonates with jaundice were selected as control group.The artery blood gas was detected by STEPHAN CPCP-B just before nCPAP treatment and at 30 min,6 h,12 h,24 h,36 h after nCPAP treatment in nCPAP group.The same method determined the artery blood gas in control group.The blood gas analysis results between nCPAP group before nCPAP treatment and control group,and between nCPAP group at different time slots and control group were analyzed by statistical methods.The procedure of this study was consistent with ethical standard which was established by the committee of investigation in human beings of West China Second University Hospital,Sichuan University.And it was approved by this committee.Guardians were informed of grouping and their written informed consent was obtained before clinical studies.There had no significance differences between two groups among gestational age at delivery,day age,and gender (P>0.05).Results There had significant difference between nCPAP group before nCPAP treatment and control group in pH value and partial pressure of oxygen in artery (Pao2) (P<0.01),but partial pressure of CO2 in artery (PaCO2 ),levels of ( HCO3ˉ ),standard bicarbonate (SB) and base excess (BE) had no significant difference (P>0.05).The blood gas results of nCPAP group at different treatment time slots and control group showed that even using nCPAP in newborns with normal Paco2 for 72 h,there were no signs of retention of CO2 (P>0.05).Conclusions Using nCPAP in newborn with normal PaCO2 for 72 h may not cause serous retention of CO2.%目的 探讨新生儿使用经鼻持续气管正压通气(nCPAP)前

  1. Effect of Continuous Positive Airway Pressure on Airway Inflammation and Oxidative Stress in Patients with Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Promsrisuk Tichanon

    2016-01-01

    Full Text Available Background. Airway inflammation and oxidative stress may be linked in obstructive sleep apnea (OSA patients. We determined the effectiveness of continuous positive airway pressure (CPAP therapy in reducing fractional exhaled nitric oxide (FeNO and malondialdehyde (MDA levels in OSA patients. Methods. Thirteen patients with OSA and 13 normal controls were recruited. FeNO and MDA levels were measured in the controls and in OSA patients before and after three months of CPAP therapy. Results. FeNO and MDA levels were higher in the patients compared to the age and gender matched controls (FeNO: 25.9 ± 5.0 versus 17.5 ± 5.9 ppb, P<0.001; MDA: 14.6 ± 7.8 versus 2.1 ± 0.3 μmol/L, P<0.001. FeNO and MDA levels were lower post-CPAP compared to pre-CPAP (FeNO: 25.9 ± 5.0 versus 17.0 ± 2.3 ppb, P<0.001; MDA: 14.6 ± 7.8 versus 10.0 ± 6.4 μmol/L, P<0.01. Apnea-hypopnea index (15.9 ± 6.6 versus 4.1 ± 2.1/h, P<0.001 and mean arterial pressure (P<0.01 decreased following CPAP treatment. Daytime mean SpO2 (P<0.05 increased. Conclusion. Our study demonstrates that CPAP therapy yields clinical benefits by reducing upper airway inflammation and oxidative stress in OSA patients.

  2. Type of mask may impact on continuous positive airway pressure adherence in apneic patients.

    Directory of Open Access Journals (Sweden)

    Jean Christian Borel

    Full Text Available RATIONALE: In obstructive sleep apnea patients (OSA, continuous positive airway pressure (CPAP adherence is crucial to improve symptoms and cardiometabolic outcomes. The choice of mask may influence CPAP adherence but this issue has never been addressed properly. OBJECTIVE: To evaluate the impact of nasal pillows, nasal and oronasal masks on CPAP adherence in a cohort of OSA. METHODS: Newly CPAP treated OSA participating in "Observatoire Sommeil de la Fédération de Pneumologie", a French national prospective cohort, were included between March 2009 and December 2011. Anthropometric data, medical history, OSA severity, sleepiness, depressive status, treatment modalities (auto-CPAP versus fixed pressure, pressure level, interface type, use of humidifiers and CPAP-related side effects were included in multivariate analysis to determine independent variables associated with CPAP adherence. RESULTS: 2311 OSA (age = 57(12 years, apnea+hypopnea index = 41(21/h, 29% female were included. Nasal masks, oronasal masks and nasal pillows were used by 62.4, 26.2 and 11.4% of the patients, respectively. In univariate analysis, oronasal masks and nasal pillows were associated with higher risk of CPAP non-adherence. CPAP non-adherence was also associated with younger age, female gender, mild OSA, gastroesophageal reflux, depression status, low effective pressure and CPAP-related side effects. In multivariate analysis, CPAP non-adherence was associated with the use of oronasal masks (OR = 2.0; 95%CI = 1.6; 2.5, depression, low effective pressure, and side effects. CONCLUSION: As oronasal masks negatively impact on CPAP adherence, a nasal mask should be preferred as the first option. Patients on oronasal masks should be carefully followed.

  3. Nap-titration : An effective alternative for continuous positive airway pressure titration

    NARCIS (Netherlands)

    Hoekema, A; Stegenga, B; Meinesz, AF; van der Hoeven, JH; Wijkstra, PJ

    2006-01-01

    When treating Obstructive Steep Apnea-Hypopnea Syndrome (OSAHS) several alternatives for standard (manual) continuous positive airway pressure (CPAP) titration are feasible. A practical alternative is titration without polysomnography during an afternoon nap (Nap-titration). The aim of the present s

  4. Motivational Interviewing (MINT) Improves Continuous Positive Airway Pressure (CPAP) Acceptance and Adherence: A Randomized Controlled Trial

    Science.gov (United States)

    Olsen, Sara; Smith, Simon S.; Oei, Tian P. S.; Douglas, James

    2012-01-01

    Objective: Adherence to continuous positive airway pressure (CPAP) therapy for obstructive sleep apnoea (OSA) is poor. We assessed the effectiveness of a motivational interviewing intervention (motivational interview nurse therapy [MINT]) in addition to best practice standard care to improve acceptance and adherence to CPAP therapy in people with…

  5. Cardiovascular risk in patients with sleep apnoea with or without continuous positive airway pressure therapy

    DEFF Research Database (Denmark)

    Lamberts, Morten; Nielsen, O W; Lip, G Y H;

    2014-01-01

    BACKGROUND: The prognostic significance of age and continuous positive airway pressure (CPAP) therapy on cardiovascular disease in patients with sleep apnoea has not been assessed previously. METHODS: Using nationwide databases, the entire Danish population was followed from 2000 until 2011. Firs...

  6. Implementation of Boussignac continuous positive airway pressure in the coronary care unit : Experiences and attitudes

    NARCIS (Netherlands)

    Dieperink, Willem; Nijsten, Maarten W. N.; van de Stadt, Mark; van der Horst, Iwan C. C.; Aarts, Leon P. H. J.; Zijlstra, Felix; Jaarsma, Tiny

    2008-01-01

    OBJECTIVE: Boussignac continuous positive airway pressure (BCPAP) delivered by face mask is useful for patients with acute cardiogenic Pulmonary edema (ACPE). Although BCPAP is medically effective, we observed that not 611 suitable patients received it. In this descriptive, prospective, cohort study

  7. The use of nasal dilator strips as a placebo for trials evaluating continuous positive airway pressure

    Directory of Open Access Journals (Sweden)

    Aline C.S. Amaro

    2012-01-01

    Full Text Available OBJECTIVES: The aim of the current study was to compare the objective and subjective effects of continuous positive airway pressure to the use of nasal dilator strips in patients with acromegaly and moderate to severe obstructive sleep apnea. METHODS: We studied 12 patients with acromegaly and moderate to severe obstructive sleep apnea (male/ females = 8/4, age = 52±8 ys, body mass index = 33.5±4.6 Kg/m², apnea-hypopnea index = 38±14 events/h who had been included in a randomized, crossover study to receive three months of treatment with continuous positive airway pressure and nasal dilator strips. All patients were evaluated at study entry and at the end of each treatment by polysomnography, and Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index and treatment satisfaction questionnaires. ClinicalTrials.gov: NCT01265121 RESULTS: The apnea-hypopnea index values decreased significantly with continuous positive airway pressure treatment but did not change with the use of nasal dilator strips. All of the subjective symptoms improved with both treatments, but these improvements were significantly greater with continuous positive airway pressure than with the nasal dilator strips CONCLUSION: The use of nasal dilator strips had a much smaller effect on the severity of obstructive sleep apnea in patients with acromegaly and moderate to severe obstructive sleep apnea in comparison to the use of continuous positive airway pressure. Moreover, the improvement in several subjective parameters without any significant objective improvement in obstructive sleep apnea resulting from the use of nasal dilator strips is compatible with a placebo effect.

  8. Oscillating Positive Airway Pressure Versus CPAP for the Treatment of Obstructive Sleep Apnea

    Science.gov (United States)

    Haba-Rubio, José; Petitpierre, Nicolas Julien; Cornette, Françoise; Tobback, Nadia; Vat, Sopharat; Giallourou, Theresia; Al-Jumaily, Ahmed; Heinzer, Raphael

    2015-01-01

    Although continuous positive airway pressure (CPAP) is the most effective therapy for obstructive sleep apnea (OSA), it is not always well tolerated by the patients. Previous physiological studies showed that pressure oscillations applied to the pharynx could activate upper airway muscles, but it is not clear whether these pressure oscillations could be tolerated during sleep in OSA patients. The aim of this study was to assess the tolerance of oscillating positive airway pressure (O-PAP) (a CPAP device delivering high-frequency pressure oscillations to the upper airway) compared to CPAP. Fourteen OSA patients currently on CPAP [age 59.9 ± 10.1 years old, BMI 34.8 ± 7.2 kg/m2, initial apnea–hypopnea index (AHI): 58.7 ± 25.2 events/h] used O-PAP or CPAP on two consecutive nights under polysomnography, in a single-blind randomized crossover design to assess sleep quality. A subtherapeutic pressure (70% of the optimal titrated pressure) was applied in both conditions and the residual AHI with each technique was also compared. There was no difference in measured or perceived sleep quality between the two treatment modalities (sleep efficiency 90.0% versus 88.1%, p = 0.54). Despite the small sample, we also found a trend toward a decrease in residual respiratory events with O-PAP compared to CPAP (median AHI 14.3 versus 20.5/h, p = 0.194). The good tolerance of O-PAP and the positive trend toward a reduction in residual AHI should stimulate further research on the effects of O-PAP in OSA patients. PMID:26029694

  9. Comparison of upper airway respiratory resistance measurements with the esophageal pressure/airflow relationship during sleep.

    Science.gov (United States)

    Morgenstern, C; Schwaibold, M; Randerath, W; Bolz, A; Jané, R

    2011-01-01

    Measurement of upper airway resistance is of interest in sleep disordered breathing to estimate upper airway patency. Resistance is calculated with the airflow and respiratory effort signals. However, there is no consensus on a standard for upper airway resistance measurement. This study proposes a new benchmarking method to objectively compare different upper airway resistance measurement methods by objectively differentiating between breaths with inspiratory flow limitation (high resistance) and non-limited breaths (low resistance). Resistance was measured at peak-Pes, at peak-flow, at the linear portion of a polynomial equation, as an area comparative and as average resistance for an inspiration. A total of 20 patients with systematic, gold-standard esophageal pressure and nasal airflow acquisition were analyzed and 109,955 breaths were automatically extracted and evaluated. Relative resistance values in relationship to a reference resistance value obtained during wakefulness were also analyzed. The peak-Pes measurement method obtained the highest separation index with significant (p < 0.001) differences to the other methods, followed by the area comparative and the peak-flow methods. As expected, average resistances were significantly (p < 0.001) lower for the non-IFL than for the IFL group. Hence, we recommend employing the peak-Pes for accurate upper airway resistance estimation.

  10. Oxygen therapy, continuous positive airway pressure, or noninvasive bilevel positive pressure ventilation in the treatment of acute cardiogenic pulmonary edema

    Directory of Open Access Journals (Sweden)

    Park Marcelo

    2001-01-01

    Full Text Available OBJECTIVE: To compare the effects of 3 types of noninvasive respiratory support systems in the treatment of acute pulmonary edema: oxygen therapy (O2, continuous positive airway pressure, and bilevel positive pressure ventilation. METHODS: We studied prospectively 26 patients with acute pulmonary edema, who were randomized into 1 of 3 types of respiratory support groups. Age was 69±7 years. Ten patients were treated with oxygen, 9 with continuous positive airway pressure, and 7 with noninvasive bilevel positive pressure ventilation. All patients received medicamentous therapy according to the Advanced Cardiac Life Support protocol. Our primary aim was to assess the need for orotracheal intubation. We also assessed the following: heart and respiration rates, blood pressure, PaO2, PaCO2, and pH at begining, and at 10 and 60 minutes after starting the protocol. RESULTS: At 10 minutes, the patients in the bilevel positive pressure ventilation group had the highest PaO2 and the lowest respiration rates; the patients in the O2 group had the highest PaCO2 and the lowest pH (p<0.05. Four patients in the O2 group, 3 patients in the continuous positive pressure group, and none in the bilevel positive pressure ventilation group were intubated (p<0.05. CONCLUSION: Noninvasive bilevel positive pressure ventilation was effective in the treatment of acute cardiogenic pulmonary edema, accelerated the recovery of vital signs and blood gas data, and avoided intubation.

  11. Genes That Influence Blood Pressure

    Science.gov (United States)

    ... Influence Blood Pressure Gene Linked to Optimism and Self-Esteem Designing New Diabetes Drugs Connect with Us Subscribe to get NIH Research Matters by email RSS Feed Facebook Email us Mailing Address: NIH Research Matters Bldg. ...

  12. Comparison of Airway Pressure Release Ventilation to Conventional Mechanical Ventilation in the Early Management of Smoke Inhalation Injury in Swine

    Science.gov (United States)

    2011-01-01

    acute respiratory distress syndrome developed ( PaO2 /FIO2 ratio ), plateau pressures were limited to ន cm H2O. Six uninjured pigs received...conventional mechanical ventilation for 48 hrs and served as time controls. Changes in PaO2 /FIO2 ratio, tidal volume, respiratory rate, mean airway pressure...plateau pressure, and hemody- namic variables were recorded. Survival was assessed using Kaplan- Meier analysis. PaO2 /FIO2 ratio was lower in airway

  13. Cost-Effectiveness of Continuous Positive Airway Pressure Therapy in Patients with Obstructive Sleep Apnea-Hypopnea in British Columbia

    Directory of Open Access Journals (Sweden)

    MCY Tan

    2008-01-01

    Full Text Available BACKGROUND: Obstructive sleep apnea-hypopnea (OSAH is a common disorder characterized by recurrent collapse of the upper airway during sleep. Patients experience a reduced quality of life and an increased risk of motor vehicle crashes (MVCs. Continuous positive airway pressure (CPAP, which is the first-line therapy for OSAH, improves sleepiness, vigilance and quality of life.

  14. Maxillomandibular Advancement Surgery as Alternative to Continuous Positive Airway Pressure in Morbidly Severe Obstructive Sleep Apnea : A Case Report

    NARCIS (Netherlands)

    Doff, Michiel H. J.; Jansma, Johan; Schepers, Rutger H.; Hoekema, Aamoud

    2013-01-01

    Obstructive sleep apnea syndrome (OSAS) is a sleep-related breathing disorder, characterized by disrupted snoring and repetitive upper airway obstructions. Oral appliance therapy is an effective alternative to continuous positive airway pressure (CPAP) and is especially effective in mild and moderat

  15. Effects of continuous positive airway pressure on upper airway inspiratory dynamics in awake patients with sleep-disordered breathing.

    Science.gov (United States)

    Vérin, E; Similowski, T; Sériès, F

    2003-01-01

    Continuous positive airway pressure (CPAP) is the main treatment of the obstructive sleep apnoea syndrome (OSAS). We assessed its effects on the upper airway (UA) dynamics in response to bilateral anterior magnetic phrenic nerve stimulation (BAMPS) in 17 awake untreated OSAS patients (15 males; 52 +/- 7 years) whose effective CPAP (P(eff)) had been determined beforehand by a conventional titration sleep study. All twitch-related inspirations were flow-limited, flow first rising to a maximum (V(Imax)), then decreasing to a minimum (V(Imin)), and then increasing again (M-shaped pattern). Up to V(Imin), the relationship between driving pressure (P(d)) and flow (V) could adequately be fitted to a polynomial regression model (V = k(1)P(d) + k(2)P(d)(2); r(2) = 0.71-0.98, P < 0.0001). At atmospheric pressure V(Imax) was 700 +/- 377 ml s(-1), V(Imin) was 458 +/- 306 ml s(-1), k(1) was 154.5 +/- 63.9 ml s(-1) (cmH(2)O)(-1), and k(2) was 10.7 +/- 7.3 ml s(-1) (cmH(2)O)(-1). CPAP significantly increased V(Imax) and V(Imin) (peak values 1007 +/- 332 ml and 837 +/- 264 ml s(-1), respectively) as well as k(1) and k(2) (peak values 300.9 +/- 178.2 ml s(-1) (cmH(2)O)(-1) and 55.2 +/- 65.3 ml s(-1) (cmH(2)O)(-1), respectively). With increasing CPAP, k(1)/k(2) increased up to a peak value before decreasing. We defined as P(eff,stim) the CPAP value corresponding to the highest k(1)/k(2) value. P(eff,stim) was correlated with P(eff) (P(eff) = 7.0 +/- 2.0; P(eff,stim) = 6.4 +/- 2.6 cmH(2)O; r = 0.886; 95 % CI 0.696-0.960, P < 0.001). We conclude that CPAP improves UA dynamics in OSAS and that the therapeutic CPAP to apply can be predicted during wakefulness using BAMPS.

  16. Altered diaphragmatic contractile properties after high airway pressure controlled mechanical ventilation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Acute respiratory failure is the most frequent indication for the application of mechanical ventilation. 1 As commonly used in clinical settings, lung protective strategies and recruitment manoeuvres are applications of higher than normal airway pressure to open the collapsed alveoli and prevent lung atelectasis caused by minimal vital ventilation. Under those conditions, we pay more attention to the lung injury and circulatory failure, and less attention to the diaphragmatic structure and function.

  17. Influence by lidocaine by intravenous injection on airway pressure during intubation anesthesia by double-lumen tube%利多卡因静脉注射对双腔气管导管插管麻醉期间气道压力的影响

    Institute of Scientific and Technical Information of China (English)

    胡秀才; 齐英凯; 韩倩; 王雷; 单士强

    2016-01-01

    Objective To investigate influence by lidocaine by intravenous injection on airway pressure during intubation anesthesia by double-lumen tube. Methods A total of 80 peripheral lung cancer patients, who received thoracoscopic lobectomy, were randomly divided into group Ⅰ and group Ⅱ, with 40 cases in each group. Group Ⅰ received lidocaine by intravenous injection before anesthesia, and continuous intravenous pumping of lidocaine after anesthesia intubation. Group Ⅱ received normal saline by intravenous injection at corresponding time point before anesthesia, and continuous intravenous pumping of normal saline after anesthesia intubation. Observation was made on plateau pressure and peak airway pressure at the time of lateral two-lung ventilation (T1), one-lung ventilation (T2), intraoperative broken bronchus (T3), and intraoperative two-lung ventilation (T4). Results Group Ⅰ had all lower plateau pressure as (15±3), (24±3), (23±3) and (21±4) cm H2O (1 cm H2O=0.098 kPa) and peak airway pressure as (18±4), (25±5), (25±3) and (23±3) cm H2O at T1, T2, T3 and T4 than group Ⅱ (P<0.05). Conclusion Preventive implement of lidocaine by intravenous injection before anesthesia induction can effectively reduce ventilation pressure and barotraumas during one-lung ventilation in thoracoscopic lobectomy patients, as well as improve one-lung ventilation effect.%目的:探讨利多卡因静脉注射对双腔气管导管插管麻醉期间气道压力的影响。方法80例周围型肺癌行胸腔镜肺叶切除术患者,随机分为组Ⅰ和组Ⅱ,各40例。组Ⅰ患者在麻醉前静脉注射利多卡因,麻醉插管后持续静脉泵注利多卡因。组Ⅱ患者在麻醉前相应时间点静脉注射生理盐水,麻醉插管后持续静脉泵注生理盐水。观察侧卧位双肺通气(T1)、单肺通气(T2)、术中离断支气管(T3)、术后双肺通气(T4)时的平台压和气道峰压。结果组Ⅰ患者 T1、T2、T3、T4时平台压(15±3)、(24±3)

  18. The NOFLO trial: low-flow nasal prongs therapy in weaning nasal continuous positive airway pressure in preterm infants.

    LENUS (Irish Health Repository)

    O'Donnell, Sinéad M

    2013-07-01

    To determine if low-flow nasal prongs therapy with room air, compared with no treatment, facilitates weaning from nasal continuous positive airway pressure (NCPAP) in very low birth weight (VLBW, birth weight <1500 g) infants.

  19. Short-term effects of positive expiratory airway pressure in patients being weaned from mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Marcelo de Mello Rieder

    2009-05-01

    Full Text Available OBJECTIVE: To investigate the feasibility and the cardiorespiratory effects of using positive expiratory airway pressure, a physiotherapeutic tool, in comparison with a T-tube, to wean patients from mechanical ventilation. METHODS/DESIGN: A prospective, randomized, cross-over study. SETTING: Two intensive care units. PATIENTS AND INTERVENTIONS: We evaluated forty patients who met weaning criteria and had been mechanically-ventilated for more than 48 hours, mean age 59 years, including 23 males. All patients were submitted to the T-tube and Expiratory Positive Airway Pressure devices, at 7 cm H2O, during a 30-minute period. Cardiorespiratory variables including work of breathing, respiratory rate (rr, peripheral oxygen saturation (SpO2, heart rate (hr, systolic, diastolic and mean arterial pressures (SAP, DAP, MAP were measured in the first and thirtieth minutes. The condition was analyzed as an entire sample set (n=40 and was also divided into subconditions: chronic obstructive pulmonary disease (n=14 and non-chronic obstructive pulmonary disease (non- chronic obstructive pulmonary disease (n=26 categories. Comparisons were made using a t-test and Analysis of Variance. The level of significance was p < 0.05. RESULTS: Our data showed an increase in work of breathing in the first and thirtieth minutes in the EPAP condition (0.86+ 0.43 and 1.02+1.3 as compared with the T-tube condition (0.25+0.26 and 0.26+0.35 (p<0.05, verified by the flow-sensor monitor (values in J/L. No statistical differences were observed when comparing the Expiratory Positive Airway Pressure and T-tube conditions with regard to cardiorespiratory measurements. The same result was observed for both chronic obstructive pulmonary disease and non- chronic obstructive pulmonary disease subconditions. CONCLUSIONS: Our study demonstrated that, in weaning patients from mechanical ventilation, the use of a fixed level of Expiratory Positive Airway Pressure caused an increase in work of

  20. Use of Biphasic Continuous Positive Airway Pressure in Premature Infant with Cleft Lip–Cleft Palate

    Directory of Open Access Journals (Sweden)

    Lovya George

    2015-10-01

    Full Text Available Preterm infants (PIs often require respiratory support due to surfactant deficiency. Early weaning from mechanical ventilation to noninvasive respiratory support decreases ventilation-associated irreversible lung damage. This wean is particularly challenging in PIs with cleft lip and cleft palate due to anatomical difficulties encountered in maintaining an adequate seal for positive pressure ventilation. PI with a cleft lip and palate often fail noninvasive respiratory support and require continued intubation and mechanical ventilation. We are presenting the first case report of a PI with cleft lip and palate who was managed by biphasic nasal continuous positive airway pressure.

  1. Retrospective, nonrandomized controlled study on autoadjusting, dual-pressure positive airway pressure therapy for a consecutive series of complex insomnia disorder patients

    Science.gov (United States)

    Krakow, Barry; McIver, Natalia D; Ulibarri, Victor A; Nadorff, Michael R

    2017-01-01

    Purpose Emerging evidence shows that positive airway pressure (PAP) treatment of obstructive sleep apnea (OSA) and upper airway resistance syndrome (UARS) in chronic insomnia patients (proposed “complex insomnia” disorder) leads to substantial decreases in insomnia severity. Although continuous PAP (CPAP) is the pressure mode most widely researched, intolerance to fixed pressurized air is rarely investigated or described in comorbidity patients. This retrospective study examined dual pressure, autoadjusting PAP modes in chronic, complex insomnia disorder patients. Patients and methods Chronic insomnia disorder patients (mean [SD] insomnia severity index [ISI] =19.11 [3.34]) objectively diagnosed with OSA or UARS and using either autobilevel PAP device or adaptive servoventilation (ASV) device after failing CPAP therapy (frequently due to intolerance to pressurized air, poor outcomes, or emergence of CSA) were divided into PAP users (≥20 h/wk) and partial users (insomnia patients, PAP users (n=246) averaged 6.10 (1.78) nightly hours and 42.71 (12.48) weekly hours and partial users (n=56) averaged 1.67 (0.76) nightly hours and 11.70 (5.31) weekly hours. For mean (SD) decreases in total ISI scores, a significant (group × time) interaction was observed (F[1,300]=13.566; Pinsomnia symptoms (r=−0.256, PInsomnia severity significantly decreased in patients using autoadjusting PAP devices, but the study design restricts interpretation to an association. Future research must elucidate the interaction between insomnia and OSA/UARS as well as the adverse influence of pressure intolerance on PAP adaptation in complex insomnia patients. Randomized controlled studies must determine whether advanced PAP modes provide benefits over standard CPAP modes in these comorbidity patients. PMID:28331381

  2. Diastolic function and functional capacity after a single session of continuous positive airway pressure in patients with compensated heart failure

    Directory of Open Access Journals (Sweden)

    Marjory Fernanda Bussoni

    2014-01-01

    Full Text Available OBJECTIVE: The effects of acute continuous positive airway pressure therapy on left ventricular diastolic function and functional capacity in patients with compensated systolic heart failure remain unclear. METHODS: This randomized, double-blind, placebo-controlled clinical trial included 43 patients with heart failure and a left ventricular ejection fraction <0.50 who were in functional classes I-III according to the New York Heart Association criteria. Twenty-three patients were assigned to continuous positive airway pressure therapy (10 cmH2O, while 20 patients received placebo with null pressure for 30 minutes. All patients underwent a 6-minute walk test (6MWT and Doppler echocardiography before and immediately after intervention. Clinicaltrials.gov: NCT01088854. RESULTS: The groups had similar clinical and echocardiographic baseline variables. Variation in the diastolic function index (e′ after intervention was associated with differences in the distance walked in both groups. However, in the continuous positive airway pressure group, this difference was greater (continuous positive airway pressure group: Δ6MWT = 9.44+16.05×Δe′, p = 0.002; sham group: Δ6MWT = 7.49+5.38×Δe′; p = 0.015. There was a statistically significant interaction between e′ index variation and continuous positive airway pressure for the improvement of functional capacity (p = 0.020. CONCLUSIONS: Continuous positive airway pressure does not acurately change the echocardiographic indexes of left ventricle systolic or diastolic function in patients with compensated systolic heart failure. However, 30-minute continuous positive airway pressure therapy appears to have an effect on left ventricular diastolic function by increasing functional capacity.

  3. Noninvasive respiratory support of juvenile rabbits by high-amplitude bubble continuous positive airway pressure.

    Science.gov (United States)

    Diblasi, Robert M; Zignego, Jay C; Tang, Dennis M; Hildebrandt, Jack; Smith, Charles V; Hansen, Thomas N; Richardson, C Peter

    2010-06-01

    Bubble continuous positive airway pressure (B-CPAP) applies small-amplitude, high-frequency oscillations in airway pressure (DeltaPaw) that may improve gas exchange in infants with respiratory disease. We developed a device, high-amplitude B-CPAP (HAB-CPAP), which provides greater DeltaPaw than B-CPAP provides. We studied the effects of different operational parameters on DeltaPaw and volumes of gas delivered to a mechanical infant lung model. In vivo studies tested the hypothesis that HAB-CPAP provides noninvasive respiratory support greater than that provided by B-CPAP. Lavaged juvenile rabbits were stabilized on ventilator nasal CPAP. The animals were then supported at the same mean airway pressure, bias flow, and fraction of inspired oxygen (FiO2) required for stabilization, whereas the bubbler angle was varied in a randomized crossover design at exit angles, relative to vertical, of 0 (HAB-CPAP0; equivalent to conventional B-CPAP), 90 (HAB-CPAP90), and 135 degrees (HAB-CPAP135). Arterial blood gases and pressure-rate product (PRP) were measured after 15 min at each bubbler angle. Pao2 levels were higher (p<0.007) with HAB-CPAP135 than with conventional B-CPAP. PaCO2 levels did not differ (p=0.073) among the three bubbler configurations. PRP with HAB-CPAP135 were half of the PRP with HAB-CPAP0 or HAB-CPAP90 (p=0.001). These results indicate that HAB-CPAP135 provides greater respiratory support than conventional B-CPAP does.

  4. Dynamic Characteristics of Mechanical Ventilation System of Double Lungs with Bi-Level Positive Airway Pressure Model

    Directory of Open Access Journals (Sweden)

    Dongkai Shen

    2016-01-01

    Full Text Available In recent studies on the dynamic characteristics of ventilation system, it was considered that human had only one lung, and the coupling effect of double lungs on the air flow can not be illustrated, which has been in regard to be vital to life support of patients. In this article, to illustrate coupling effect of double lungs on flow dynamics of mechanical ventilation system, a mathematical model of a mechanical ventilation system, which consists of double lungs and a bi-level positive airway pressure (BIPAP controlled ventilator, was proposed. To verify the mathematical model, a prototype of BIPAP system with a double-lung simulators and a BIPAP ventilator was set up for experimental study. Lastly, the study on the influences of key parameters of BIPAP system on dynamic characteristics was carried out. The study can be referred to in the development of research on BIPAP ventilation treatment and real respiratory diagnostics.

  5. Residual Daytime Sleepiness in Obstructive Sleep Apnea After Continuous Positive Airway Pressure Optimization: Causes and Management.

    Science.gov (United States)

    Chapman, Julia L; Serinel, Yasmina; Marshall, Nathaniel S; Grunstein, Ronald R

    2016-09-01

    Excessive daytime sleepiness (EDS) is common in obstructive sleep apnea (OSA), but it is also common in the general population. When sleepiness remains after continuous positive airway pressure (CPAP) treatment of OSA, comorbid conditions or permanent brain injury before CPAP therapy may be the cause of the residual sleepiness. There is currently no broad approach to treating residual EDS in patients with OSA. Individual assessment must be made of comorbid conditions and medications, and of lifestyle factors that may be contributing to the sleepiness. Modafinil and armodafinil are the only pharmacologic agents indicated for residual sleepiness in these patients.

  6. Unidirectional Expiratory Valve Method to Assess Maximal Inspiratory Pressure in Individuals without Artificial Airway.

    Directory of Open Access Journals (Sweden)

    Samantha Torres Grams

    Full Text Available Maximal Inspiratory Pressure (MIP is considered an effective method to estimate strength of inspiratory muscles, but still leads to false positive diagnosis. Although MIP assessment with unidirectional expiratory valve method has been used in patients undergoing mechanical ventilation, no previous studies investigated the application of this method in subjects without artificial airway.This study aimed to compare the MIP values assessed by standard method (MIPsta and by unidirectional expiratory valve method (MIPuni in subjects with spontaneous breathing without artificial airway. MIPuni reproducibility was also evaluated.This was a crossover design study, and 31 subjects performed MIPsta and MIPuni in a random order. MIPsta measured MIP maintaining negative pressure for at least one second after forceful expiration. MIPuni evaluated MIP using a unidirectional expiratory valve attached to a face mask and was conducted by two evaluators (A and B at two moments (Tests 1 and 2 to determine interobserver and intraobserver reproducibility of MIP values. Intraclass correlation coefficient (ICC[2,1] was used to determine intraobserver and interobserver reproducibility.The mean values for MIPuni were 14.3% higher (-117.3 ± 24.8 cmH2O than the mean values for MIPsta (-102.5 ± 23.9 cmH2O (p<0.001. Interobserver reproducibility assessment showed very high correlation for Test 1 (ICC[2,1] = 0.91, and high correlation for Test 2 (ICC[2,1] = 0.88. The assessment of the intraobserver reproducibility showed high correlation for evaluator A (ICC[2,1] = 0.86 and evaluator B (ICC[2,1] = 0.77.MIPuni presented higher values when compared with MIPsta and proved to be reproducible in subjects with spontaneous breathing without artificial airway.

  7. Unidirectional Expiratory Valve Method to Assess Maximal Inspiratory Pressure in Individuals without Artificial Airway

    Science.gov (United States)

    Grams, Samantha Torres; Kimoto, Karen Yumi Mota; Azevedo, Elen Moda de Oliveira; Lança, Marina; de Albuquerque, André Luis Pereira; de Brito, Christina May Moran; Yamaguti, Wellington Pereira

    2015-01-01

    Introduction Maximal Inspiratory Pressure (MIP) is considered an effective method to estimate strength of inspiratory muscles, but still leads to false positive diagnosis. Although MIP assessment with unidirectional expiratory valve method has been used in patients undergoing mechanical ventilation, no previous studies investigated the application of this method in subjects without artificial airway. Objectives This study aimed to compare the MIP values assessed by standard method (MIPsta) and by unidirectional expiratory valve method (MIPuni) in subjects with spontaneous breathing without artificial airway. MIPuni reproducibility was also evaluated. Methods This was a crossover design study, and 31 subjects performed MIPsta and MIPuni in a random order. MIPsta measured MIP maintaining negative pressure for at least one second after forceful expiration. MIPuni evaluated MIP using a unidirectional expiratory valve attached to a face mask and was conducted by two evaluators (A and B) at two moments (Tests 1 and 2) to determine interobserver and intraobserver reproducibility of MIP values. Intraclass correlation coefficient (ICC[2,1]) was used to determine intraobserver and interobserver reproducibility. Results The mean values for MIPuni were 14.3% higher (-117.3 ± 24.8 cmH2O) than the mean values for MIPsta (-102.5 ± 23.9 cmH2O) (p<0.001). Interobserver reproducibility assessment showed very high correlation for Test 1 (ICC[2,1] = 0.91), and high correlation for Test 2 (ICC[2,1] = 0.88). The assessment of the intraobserver reproducibility showed high correlation for evaluator A (ICC[2,1] = 0.86) and evaluator B (ICC[2,1] = 0.77). Conclusions MIPuni presented higher values when compared with MIPsta and proved to be reproducible in subjects with spontaneous breathing without artificial airway. PMID:26360255

  8. Upper airway collapsibility evaluated by a negative expiratory pressure test in severe obstructive sleep apnea

    Directory of Open Access Journals (Sweden)

    Salvatore Romano

    2011-01-01

    Full Text Available OBJECTIVES: To investigate the usefulness of measuring upper airway collapsibility with a negative expiratory pressure application as a screening test for severe obstructive sleep apnea (OSA. INTRODUCTION: OSA is a risk factor for cardiovascular disease, and it may have serious consequences. Its recognition may have important implications during the perioperative period. Increased upper airway collapsibility is one of the main determinants of OSA, and its evaluation could be useful for identifying this condition. METHODS: Severe OSA and normal subjects (24 in each group were matched by body mass index and referred to our sleep laboratory. The subjects were enrolled in an overnight sleep study, and a diurnal negative expiratory pressure test was performed. Flow drop (DV and expiratory volume were measured in the first 0.2 s (V02 of the negative expiratory pressure test. RESULTS: DV (% and V02 (% values were statistically different between normal and OSA subjects. OSA patients showed a greater decrease in flow than normal subjects. In addition, severely OSA patients exhaled during the first 0.2 s of the negative expiratory pressure application was an average of only 11.2% of the inspired volume compared to 34.2% for the normal subjects. Analysis of the receiver operating characteristics showed that V02 (% and DV (% could accurately identify severe OSA in subjects with sensitivities of 95.8% and 91.7%, respectively, and specificities of 95.8% and 91.7%, respectively. CONCLUSIONS: V02 (% and DV (% are highly accurate parameters for detecting severe OSA. The pharyngeal collapsibility measurement, which uses negative expiratory pressure during wakefulness, is predictive of collapsibility during sleep.

  9. Successful treatment of laryngomalacia and bilateral vocal cord paralysis with continuous positive airway pressure

    Directory of Open Access Journals (Sweden)

    Sovtić Aleksandar

    2010-01-01

    Full Text Available Introduction Laryngomalacia is the most frequent congenital anomaly of airways, and it may cause obstructive sleep apneas. The associated vocal cord paralysis may aggravate the symptoms of upper airway obstruction. Case report In a 14 month old boy severe laryngomalacia and bilateral vocal cord paralysis were diagnosed by flexible bronchoscopy. A sleep study showed a severe obstructive sleep apnoea (OSA. The patient was ventilated at home via the face mask with non invasive mechanical ventilation (CPAP for a year. The level of pressure had to be set at 7cm H2O to correct desaturation with an improvement in mean SpO2. On the follow up bronchoscopic examination laryngomalatia was improved, vocal cord paralysis persisted and sleep study revealed significant improvement. Discussion In the patient with severe laryngomalatia and bilateral vocal cord paralysis with OSA conservative treatment with CPAP was used instead of a surgical intervention. Non invasive ventilation was used every night, for at least 6 hours, without adverse events. Invasive measurement of transdiaphragmatic pressure is the best way of titrating of CPAP level. This case report suggests the efficacy of noninvasive titrating of CPAP level by the hemoglobin oxygen saturation trend measurement. Conclusion In case of severe laryngomalatia and associated vocal cord paralysis, followed by OSA non invasive ventilation by nasal CPAP represents an effective and safe alternative to surgery.

  10. Continuous positive airway pressure ameliorated severe pulmonary hypertension associated with obstructive sleep apnea.

    Directory of Open Access Journals (Sweden)

    Ogawa,Aiko

    2006-06-01

    Full Text Available

    A 52-year-old obese woman was admitted to our institution for evaluation of dyspnea and pulmonary hypertension (PH. Polysomnography revealed severe obstructive sleep apnea (OSA with an apnea hypopnea index of 99.8. Treatment with nocturnal continuous positive airway pressure (CPAP resulted in correction of daytime hypoxemia, hypercapnia, and near-normalization of pulmonary artery pressure. To our knowledge, this is the most severe case of OSA-associated PH (approximately70 mmHg reported to date, and it was successfully treated with nocturnal CPAP. This case demonstrates that OSA should be considered and polysomnography performed in all patients with PH, irrespective of severity, and that nocturnal CPAP has therapeutic effects on both OSA and daytime PH.

  11. Influence of horse stable environment on human airways

    Directory of Open Access Journals (Sweden)

    Pringle John

    2009-05-01

    Full Text Available Abstract Background Many people spend considerable amount of time each day in equine stable environments either as employees in the care and training of horses or in leisure activity. However, there are few studies available on how the stable environment affects human airways. This study examined in one horse stable qualitative differences in indoor air during winter and late summer conditions and assessed whether air quality was associated with clinically detectable respiratory signs or alterations to selected biomarkers of inflammation and lung function in stable personnel. Methods The horse stable environment and stable-workers (n = 13 in one stable were investigated three times; first in the winter, second in the interjacent late summer and the third time in the following winter stabling period. The stable measurements included levels of ammonia, hydrogen sulphide, total and respirable dust, airborne horse allergen, microorganisms, endotoxin and glucan. The stable-workers completed a questionnaire on respiratory symptoms, underwent nasal lavage with subsequent analysis of inflammation markers, and performed repeated measurements of pulmonary function. Results Measurements in the horse stable showed low organic dust levels and high horse allergen levels. Increased viable level of fungi in the air indicated a growing source in the stable. Air particle load as well as 1,3-β-glucan was higher at the two winter time-points, whereas endotoxin levels were higher at the summer time-point. Two stable-workers showed signs of bronchial obstruction with increased PEF-variability, increased inflammation biomarkers relating to reported allergy, cold or smoking and reported partly work-related symptoms. Furthermore, two other stable-workers reported work-related airway symptoms, of which one had doctor's diagnosed asthma which was well treated. Conclusion Biomarkers involved in the development of airway diseases have been studied in relation to

  12. Distending Pressure Did Not Activate Acute Phase or Inflammatory Responses in the Airways and Lungs of Fetal, Preterm Lambs.

    Directory of Open Access Journals (Sweden)

    Rebecca Y Petersen

    Full Text Available Mechanical ventilation at birth causes airway injury and lung inflammation in preterm sheep. Continuous positive airway pressure (CPAP is being increasingly used clinically to transition preterm infants at birth.To test if distending pressures will activate acute phase reactants and inflammatory changes in the airways of fetal, preterm lambs.The head and chest of fetal lambs at 128±1 day GA were surgically exteriorized. With placental circulation intact, fetal lambs were then randomized to one of five 15 minute interventions: PEEP of 0, 4, 8, 12, or 16 cmH2O. Recruitment volumes were recorded. Fetal lambs remained on placental support for 30 min after the intervention. The twins of each 0 cmH2O animal served as controls. Fetal lung fluid (FLF, bronchoalveolar lavage fluid (BAL, right mainstem bronchi and peripheral lung tissue were evaluated for inflammation.Recruitment volume increased from 0.4±0.04 mL/kg at 4 cmH2O to 2.4±0.3 mL/kg at 16 cmH2O. The lambs were surfactant deficient, and all pressures were below the opening inflection pressure on pressure-volume curve. mRNA expression of early response genes and pro-inflammatory cytokines did not increase in airway tissue or lung tissue at any pressure compared to controls. FLF and BAL also did not have increases in early response proteins. No histologic changes or Egr-1 activation was present at the pressures used.Distending pressures as high as 16 cmH2O did not recruit lung volume at birth and did not increase markers of injury in the lung or airways in non-breathing preterm fetal sheep.

  13. The influence of upper airways diameter on the intensity of obstructive sleep apnea

    Directory of Open Access Journals (Sweden)

    Jolanta Szymańska

    2014-03-01

    Full Text Available Introduction and Objective. Obstructive sleep apnea (OSA is characterized by at least 5 ten-second-long episodes of apnea or hypopnea, per hour of sleep. This disease may lead to severe, life-threatening complications. Therefore, risk analysis and its influence on disease intensity is crucial for proper implementation of preventive treatments. Objective. To determine the relation between the intensity of OSA expressed in Apnea-Hypopnea Index (AHI, and the anterior-posterior diameter of upper airways at the levels of soft palate and tongue base. Material and Method. Medical records of 41 patients with sleep apnea (AHI>4 diagnosed through polysomnographic examination obstructive were used for the study. The data consisted of: age and gender, polysomnographic examination results (AHI, lateral cephalogram with cephalomertic analysis, together with measurements of the upper and lower pharyngeal depth according to McNamara. Statistical analysis was carried out in accordance with Pearson’s r correlation coefficient test (Statistica 8.0 software package. Results. Analysis of the influence of upper airways diameter on the intensity of OSA showed that the value of upper Airways diameter at the tongue base level had no statistically significant impact on the value of AHI (p=0.795. However, a statistically significant impact of the value of upper airways diameter on the AHI value (p=0.008 at the soft palate level was observed. Patients with OSA have narrowed upper airways diameter. The value of AHI increases with the decrease of upper diameter and is not dependent on a lower diameter value. Patients with a decreased upper airways diameter should be informed about potential breathing disorders during sleep.

  14. Nasal continuous positive airway pressure (CPAP) for the respiratory care of the newborn infant.

    Science.gov (United States)

    Diblasi, Robert M

    2009-09-01

    Nasal continuous positive airway pressure (CPAP) is a noninvasive form of respiratory assistance that has been used to support spontaneously breathing infants with lung disease for nearly 40 years. Following reports that mechanical ventilation contributes to pulmonary growth arrest and the development of chronic lung disease, there is a renewed interest in using CPAP as the prevailing method for supporting newborn infants. Animal and human research has shown that CPAP is less injurious to the lungs than is mechanical ventilation. The major concepts that embrace lung protection during CPAP are the application of spontaneous breathing at a constant distending pressure and avoidance of intubation and positive-pressure inflations. A major topic for current research focuses on whether premature infants should be supported initially with CPAP following delivery, or after the infant has been extubated following prophylactic surfactant administration. Clinical trials have shown that CPAP reduces the need for intubation/mechanical ventilation and surfactant administration, but it is still unclear whether CPAP reduces chronic lung disease and mortality, compared to modern lung-protective ventilation techniques. Despite the successes, little is known about how best to manage patients using CPAP. It is also unclear whether different strategies or devices used to maintain CPAP play a role in improving outcomes in infants. Nasal CPAP technology has evolved over the last 10 years, and bench and clinical research has evaluated differences in physiologic effects related to these new devices. Ultimately, clinicians' abilities to perceive changes in the pathophysiologic conditions of infants receiving CPAP and the quality of airway care provided are likely to be the most influential factors in determining patient outcomes.

  15. Obstructive sleep apnea syndrome, continuous positive airway pressure and treatment of hypertension.

    Science.gov (United States)

    Floras, John S

    2015-09-15

    Obstructive sleep apnea (OSA), present in ~15% of the general population, increases the risks of stroke, heart failure, and premature death. Importantly, individuals with cardiovascular disease have a higher prevalence yet they often have few symptoms to alert clinicians to its presence. OSA with an apnea-hypopnea index (AHI) ≥15 events/hour is present in ≥30% of patients with primary hypertension and in up to 80% of those with drug resistant hypertension, suggesting that the neural, hormonal, inflammatory and vascular cascades triggered by OSA may elevate blood pressure chronically. The purpose of this review is to summarize: (1) the epidemiology of OSA and its relation to cardiovascular risk; (2) potential mechanisms by which OSA could promote conditions known to increase the risk of hypertension or contribute to its development and progression; (3) evidence for and against a pro-hypertensive effect of OSA; and, (4) the impact of treatment with continuous positive airway pressure (CPAP) on blood pressure and blood pressure-related morbidities. The prevailing view that the effect of treatment on blood pressure is modest arises from the inability of most contemporary technology to measure accurately the true impact of CPAP on OSA-entrained surges in nocturnal blood pressure. Moreover the exclusive focus on blood pressure, as if this is the principal determinant of cardiovascular event rates in this population, is naïve. The capacity to reduce cardiovascular risk by treating OSA with CPAP likely transcends a simple blood pressure effect; formal testing of this hypothesis will require adequately powered randomized clinical trials.

  16. Effect of continuous positive airway pressure therapy on hypothalamic-pituitary-adrenal axis function and 24-h blood pressure profile in obese men with obstructive sleep apnea syndrome.

    Science.gov (United States)

    Carneiro, Gláucia; Togeiro, Sônia Maria; Hayashi, Lílian F; Ribeiro-Filho, Fernando Flexa; Ribeiro, Artur Beltrame; Tufik, Sérgio; Zanella, Maria Teresa

    2008-08-01

    Obstructive sleep apnea syndrome (OSAS) increases the risk of cardiovascular events. Sympathetic nervous system and hypothalamic-pituitary-adrenal (HPA) axis activation may be the mechanism of this relationship. The aim of this study was to evaluate HPA axis and ambulatory blood pressure monitoring in obese men with and without OSAS and to determine whether nasal continuous positive airway pressure therapy (nCPAP) influenced responses. Twenty-four-hour ambulatory blood pressure monitoring and overnight cortisol suppression test with 0.25 mg of dexamethasone were performed in 16 obese men with OSAS and 13 obese men controls. Nine men with severe apnea were reevaluated 3 mo after nCPAP therapy. Body mass index and blood pressure of OSAS patients and obese controls were similar. In OSAS patients, the percentage of fall in systolic blood pressure at night (P = 0.027) and salivary cortisol suppression postdexamethasone (P = 0.038) were lower, whereas heart rate (P = 0.022) was higher compared with obese controls. After nCPAP therapy, patients showed a reduction in heart rate (P = 0.036) and a greater cortisol suppression after dexamethasone (P = 0.001). No difference in arterial blood pressure (P = 0.183) was observed after 3 mo of nCPAP therapy. Improvement in cortisol suppression was positively correlated with an improvement in apnea-hypopnea index during nCPAP therapy (r = 0.799, P = 0.010). In conclusion, men with OSAS present increased postdexamethasone cortisol levels and heart rate, which were recovered by nCPAP.

  17. Efficacy of Home Single-Channel Nasal Pressure for Recommending Continuous Positive Airway Pressure Treatment in Sleep Apnea

    Science.gov (United States)

    Masa, Juan F.; Duran-Cantolla, Joaquin; Capote, Francisco; Cabello, Marta; Abad, Jorge; Garcia-Rio, Francisco; Ferrer, Antoni; Fortuna, Ana M.; Gonzalez-Mangado, Nicolas; de la Peña, Monica; Aizpuru, Felipe; Barbe, Ferran; Montserrat, Jose M.; Larrateguy, Luis D.; de Castro, Jorge Rey; Garcia-Ledesma, Estefania; Corral, Jaime; Martin-Vicente, Maria J.; Martinez-Null, Cristina; Egea, Carlos; Cancelo, Laura; García-Díaz, Emilio; Carmona-Bernal, Carmen; Sánchez-Armengol, Ángeles; Mayos, Merche; Miralda, Rosa M; Troncoso, Maria F.; Gonzalez, Monica; Martinez-Martinez, Marian; Cantalejo, Olga; Piérola, Javier; Vigil, Laura; Embid, Cristina; del Mar Centelles, Mireia; Prieto, Teresa Ramírez; Rojo, Blas; Lores, Vanesa

    2015-01-01

    Introduction: Unlike other prevalent diseases, obstructive sleep apnea (OSA) has no simple tool for diagnosis and therapeutic decision-making in primary healthcare. Home single-channel nasal pressure (HNP) may be an alternative to polysomnography for diagnosis but its use in therapeutic decisions has yet to be explored. Objectives: To ascertain whether an automatically scored HNP apnea-hypopnea index (AHI), used alone to recommend continuous positive airway pressure (CPAP) treatment, agrees with decisions made by a specialist using polysomnography and several clinical variables. Methods: Patients referred by primary care physicians for OSA suspicion underwent randomized polysomnography and HNP. We analyzed the total sample and both more and less symptomatic subgroups for Bland and Altman plots to explore AHI agreement; receiver operating characteristic curves to establish area under the curve (AUC) measurements for CPAP recommendation; and therapeutic decision efficacy for several HNP AHI cutoff points. Results: Of the 787 randomized patients, 35 (4%) were lost, 378 (48%) formed the more symptomatic and 374 (48%) the less symptomatic subgroups. AHI bias and agreement limits were 5.8 ± 39.6 for the total sample, 5.3 ± 38.7 for the more symptomatic, and 6 ± 40.2 for the less symptomatic subgroups. The AUC were 0.826 for the total sample, 0.903 for the more symptomatic, and 0.772 for the less symptomatic subgroups. In the more symptomatic subgroup, 70% of patients could be correctly treated with CPAP. Conclusion: Automatic home single-channel nasal pressure scoring can correctly recommend CPAP treatment in most of more symptomatic patients with OSA suspicion. Our results suggest that this device may be an interesting tool in initial OSA management for primary care physicians, although future studies in a primary care setting are necessary. Clinical Trials Information: Clinicaltrial.gov identifier: NCT01347398. Citation: Masa JF, Duran-Cantolla J, Capote F, Cabello

  18. Continuous positive airway pressure and noninvasive ventilation in prehospital treatment of patients with acute respiratory failure

    DEFF Research Database (Denmark)

    Bakke, Skule A; Bøtker, Morten Thingemann; Riddervold, Ingunn S;

    2014-01-01

    Continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV) are frequently used inhospital for treating respiratory failure, especially in treatment of acute cardiogenic pulmonary edema and exacerbation of chronic obstructive pulmonary disease. Early initiation of treatment...... is important for success and introduction already in the prehospital setting may be beneficial. Our goal was to assess the evidence for an effect of prehospital CPAP or NIV as a supplement to standard medical treatment alone on the following outcome measures; mortality, hospital length of stay, intensive care...... examine prehospital CPAP. Of these, only one small, randomized controlled trial shows a reduced mortality rate and a reduced intubation rate with supplemental CPAP. The other three studies have neutral findings, but in two of these a trend toward lower intubation rate is found. The effect of supplemental...

  19. Continuous positive airway pressure breathing increases cranial spread of sensory blockade after cervicothoracic epidural injection of lidocaine.

    NARCIS (Netherlands)

    Visser, W.A.; Eerd, M.J. van; Seventer, R. van; Gielen, M.J.M.; Giele, J.L.P.; Scheffer, G.J.

    2007-01-01

    BACKGROUND: Continuous positive airway pressure (CPAP) increases the caudad spread of sensory blockade after low-thoracic epidural injection of lidocaine. We hypothesized that CPAP would increase cephalad spread of blockade after cervicothoracic epidural injection. METHODS: Twenty patients with an e

  20. Simulated driving in obstructive sleep apnoea-hypopnoea : effects of oral appliances and continuous positive airway pressure

    NARCIS (Netherlands)

    Hoekema, Aarnoud; Stegenga, Boudewijn; Bakker, Marije; Brouwer, Wiebo H.; de Bont, Lambert G. M.; Wijkstra, Peter J.; van der Hoeven, Johannes H.

    2007-01-01

    Impaired simulated driving performance has been demonstrated in obstructive sleep apnoea-hypopnoea syndrome (OSAHS) patients. Although continuous positive airway pressure (CPAP) generally improves simulated driving performance, the effects of oral-appliance (OA) therapy are unknown. The aims of this

  1. Infants with severe respiratory syncytial virus needed less ventilator time with nasal continuous airways pressure then invasive mechanical ventilation

    NARCIS (Netherlands)

    Borckink, Ilse; Essouri, Sandrine; Laurent, Marie; Albers, Marcel J. I. J.; Burgerhof, Johannes G. M.; Tissieres, Pierre; Kneyber, Martin C. J.

    2014-01-01

    AIM: Nasal continuous positive airway pressure (NCPAP) has been proposed as an early first-line support for infants with severe respiratory syncytial virus (RSV) infection. We hypothesised that infants <6 months with severe RSV would require shorter ventilator support on NCPAP than invasive mechanic

  2. Safety and Effectiveness of Bubble Continuous Positive Airway Pressure in Neonates With Respiratory Distress and Its Failure Factors

    Directory of Open Access Journals (Sweden)

    Ajay Sethi

    2015-09-01

    Conclusion: Bubble Continuous Positive Airway Pressure is safe, efficacious and easy to use in preterm and term neonates with mild to moderate respiratory distress. The major failure factors in our study were sepsis, recurrent apnea, and shock. The survival rate in our study was 60%. [Natl J Med Res 2015; 5(3.000: 202-206

  3. A Randomized Trial of Low-Flow Oxygen versus Nasal Continuous Positive Airway Pressure in Preterm Infants

    DEFF Research Database (Denmark)

    Heiring, Christian; Steensberg, Jesper; Bjerager, Mia

    2015-01-01

    BACKGROUND: Nasal continuous positive airway pressure (nCPAP) stabilizes the residual volume and may decrease the risk of 'atelectotrauma', potentially promoting lung development in neonates. OBJECTIVES: To assess whether replacing nCPAP by low-flow O2 by nasal cannula affects lung function expre...

  4. Otic Barotrauma Resulting from Continuous Positive Airway Pressure: Case Report and Literature Review

    Science.gov (United States)

    McCormick, Justin P.; Hildrew, Douglas M.; Lawlor, Claire M.; Guittard, Jesse A.; Worley, N. Knight

    2016-01-01

    Background: Obstructive sleep apnea (OSA) is a growing problem affecting millions of people in the United States. The prevalence of OSA has risen drastically in the past few decades concurrently with the increasing prevalence of obesity. Subsequently, there has been an ever-increasing rise in the use of continuous positive airway pressure (CPAP) devices. While using CPAP devices may lead to many adverse effects, the majority of these effects are described as relatively benign. Case Report: We describe the detailed clinical course and outcome for a patient with otic barotrauma as a result of excessive self-titration of CPAP therapy in an in-home setting. We also discuss the pathophysiology of otic barotrauma and present a review of current literature on the topic. Conclusion: While the benefits of CPAP are clear, we must take into account the rare but possible effects on ear structure and function. Many studies describe an increase in middle ear pressure with the use of CPAP, but few describe the effects of this increased pressure on the middle ear, such as the otic barotrauma described in this case. Given the increased prevalence of OSA, it is important to understand the risks associated with CPAP therapy. PMID:27303224

  5. Lung pressures and gas transport during high-frequency airway and chest wall oscillation.

    Science.gov (United States)

    Khoo, M C; Ye, T H; Tran, N H

    1989-09-01

    The major goal of this study was to compare gas exchange, tidal volume (VT), and dynamic lung pressures resulting from high-frequency airway oscillation (HFAO) with the corresponding effects in high-frequency chest wall oscillation (HFCWO). Eight anesthetized paralyzed dogs were maintained eucapnic with HFAO and HFCWO at frequencies ranging from 1 to 16 Hz in the former and 0.5 to 8 Hz in the latter. Tracheal (delta Ptr) and esophageal (delta Pes) pressure swings, VT, and arterial blood gases were measured in addition to respiratory impedance and static pressure-volume curves. Mean positive pressure (25-30 cmH2O) in the chest cuff associated with HFCWO generation decreased lung volume by approximately 200 ml and increased pulmonary impedance significantly. Aside from this decrease in functional residual capacity (FRC), no change in lung volume occurred as a result of dynamic factors during the course of HFCWO application. With HFAO, a small degree of hyperinflation occurred only at 16 Hz. Arterial PO2 decreased by 5 Torr on average during HFCWO. VT decreased with increasing frequency in both cases, but VT during HFCWO was smaller over the range of frequencies compared with HFAO. delta Pes and delta Ptr between 1 and 8 Hz were lower than the corresponding pressure swings obtained with conventional mechanical ventilation (CMV) applied at 0.25 Hz. delta Pes was minimized at 1 Hz during HFCWO; however, delta Ptr decreased continuously with decreasing frequency and, below 2 Hz, became progressively smaller than the corresponding values obtained with HFAO and CMV.

  6. Effect of Nasal Obstruction on Continuous Positive Airway Pressure Treatment: Computational Fluid Dynamics Analyses.

    Directory of Open Access Journals (Sweden)

    Tadashi Wakayama

    Full Text Available Nasal obstruction is a common problem in continuous positive airway pressure (CPAP therapy for obstructive sleep apnea and limits treatment compliance. The purpose of this study is to model the effects of nasal obstruction on airflow parameters under CPAP using computational fluid dynamics (CFD, and to clarify quantitatively the relation between airflow velocity and pressure loss coefficient in subjects with and without nasal obstruction.We conducted an observational cross-sectional study of 16 Japanese adult subjects, of whom 9 had nasal obstruction and 7 did not (control group. Three-dimensional reconstructed models of the nasal cavity and nasopharynx with a CPAP mask fitted to the nostrils were created from each subject's CT scans. The digital models were meshed with tetrahedral cells and stereolithography formats were created. CPAP airflow simulations were conducted using CFD software. Airflow streamlines and velocity contours in the nasal cavities and nasopharynx were compared between groups. Simulation models were confirmed to agree with actual measurements of nasal flow rate and with pressure and flow rate in the CPAP machine.Under 10 cmH2O CPAP, average maximum airflow velocity during inspiration was 17.6 ± 5.6 m/s in the nasal obstruction group but only 11.8 ± 1.4 m/s in the control group. The average pressure drop in the nasopharynx relative to inlet static pressure was 2.44 ± 1.41 cmH2O in the nasal obstruction group but only 1.17 ± 0.29 cmH2O in the control group. The nasal obstruction and control groups were clearly separated by a velocity threshold of 13.5 m/s, and pressure loss coefficient threshold of approximately 10.0. In contrast, there was no significant difference in expiratory pressure in the nasopharynx between the groups.This is the first CFD analysis of the effect of nasal obstruction on CPAP treatment. A strong correlation between the inspiratory pressure loss coefficient and maximum airflow velocity was found.

  7. Mathematical Equations to Predict Positive Airway Pressures for Obstructive Sleep Apnea: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Macario Camacho

    2015-01-01

    Full Text Available Objective. To systematically review the international literature for mathematical equations used to predict effective pressures for positive airway pressure (PAP devices. Methods. Google Scholar, PubMed, Scopus, Embase, Web of Science, CINAHL, and The Cochrane Library were searched through June 27, 2015. The PRISMA statement was followed. There was no language limitation. Results. 709 articles were screened, fifty were downloaded, and twenty-six studies presented equations that met the inclusion and exclusion criteria. In total, there were 4,436 patients in the development phases and 3,489 patients in the validation phases. Studies performed multiple linear regressions analyses as part of the equation(s development and included the following variables: physical characteristics, polysomnography data, behavioral characteristics, and miscellaneous characteristics, which were all predictive to a variable extent. Of the published variables, body mass index (BMI and mean oxygen saturation are the most heavily weighted, while BMI (eighteen studies, apnea-hypopnea index (seventeen studies, and neck circumference (eleven studies were the variables most frequently used in the mathematical equations. Ten studies were from Asian countries and sixteen were from non-Asian countries. Conclusion. This systematic review identified twenty-six unique studies reporting mathematical equations which are summarized. Overall, BMI and mean oxygen saturation are the most heavily weighted.

  8. Mathematical Equations to Predict Positive Airway Pressures for Obstructive Sleep Apnea: A Systematic Review

    Science.gov (United States)

    Camacho, Macario; Riaz, Muhammad; Tahoori, Armin; Certal, Victor; Kushida, Clete A.

    2015-01-01

    Objective. To systematically review the international literature for mathematical equations used to predict effective pressures for positive airway pressure (PAP) devices. Methods. Google Scholar, PubMed, Scopus, Embase, Web of Science, CINAHL, and The Cochrane Library were searched through June 27, 2015. The PRISMA statement was followed. There was no language limitation. Results. 709 articles were screened, fifty were downloaded, and twenty-six studies presented equations that met the inclusion and exclusion criteria. In total, there were 4,436 patients in the development phases and 3,489 patients in the validation phases. Studies performed multiple linear regressions analyses as part of the equation(s) development and included the following variables: physical characteristics, polysomnography data, behavioral characteristics, and miscellaneous characteristics, which were all predictive to a variable extent. Of the published variables, body mass index (BMI) and mean oxygen saturation are the most heavily weighted, while BMI (eighteen studies), apnea-hypopnea index (seventeen studies), and neck circumference (eleven studies) were the variables most frequently used in the mathematical equations. Ten studies were from Asian countries and sixteen were from non-Asian countries. Conclusion. This systematic review identified twenty-six unique studies reporting mathematical equations which are summarized. Overall, BMI and mean oxygen saturation are the most heavily weighted. PMID:26294977

  9. Effects of nasal continuous positive airway pressure therapy on partners' sexual lives.

    Science.gov (United States)

    Acar, Mustafa; Kaya, Coskun; Catli, Tolgahan; Hancı, Deniz; Bolluk, Ozge; Aydin, Yunus

    2016-01-01

    To assess sexual functioning in male and female partners before and after nasal continuous positive airway pressure (CPAP) therapy in men with obstructive sleep apnea (OSA). Twenty-one male patients with moderate to severe OSA and erectile dysfunction, and their female partner, were recruited into this prospective study. Males diagnosed with OSA were treated with nasal CPAP therapy for 12 weeks. Women were assessed for sexual functioning using the Female Sexual Function Index (FSFI), and for mood status using the Beck Depression Inventory (BDI), before and after their male partner underwent nasal CPAP therapy. Sexual functioning was assessed in men using the International Index of Erectile Function (IIEF), before and after nasal CPAP therapy. After nasal CPAP therapy for OSA in men, IIEF scores were significantly higher than pre-treatment scores. Total pre- and post-treatment IIEF scores (mean ± standard deviation) were 50.28 ± 15.88 and 65.42 ± 7.47, respectively, P sexual functioning in both the male and female partners. Moreover, our findings indicate that improved sexual function in women after their male partner underwent nasal CPAP also had psychological benefits.

  10. Noninvasive Positive Airway Pressure Treatment in Children Less Than 12 Months of Age

    Directory of Open Access Journals (Sweden)

    Adetayo Adeleye

    2016-01-01

    Full Text Available Study Objectives. We identified the associated conditions of patients less than 12 months of age who were referred for polysomnogram (PSG studies. We collated PSG findings and physician interpretation. We determined the correlation between the recommended treatment by the PSG interpreting physician and actual prescribed treatment by the referring or subjects’ physician. We determined adherence with noninvasive positive airway pressure (PAP treatment. Methods. This was a retrospective cohort study. Participants included children less than 12 months of age referred for PSG studies between 2007 and 2012. Results. 92 patients under the age of 12 months were included in the study analysis. Mean (standard deviation, SD age in days at time of the PSG study was 208.5 (101.2. 35 (38% patients had a diagnosis of Trisomy 21. Seven (8% patients had no prior diagnosis. Median (Q1, Q3 apnea hypopnea index (AHI was 22.5 (11.3–37.0. Agreement between the PSG interpreting physician’s recommendation and actual prescribed treatment by the referring or subjects’ physician was 85.9% [95% CI 77.1–91.6]. Mean (SD percentage days with PAP therapy usage more than 4 hours was 25.2% (32. Conclusions. In our experience, despite consistent physician messaging to families, adherence with noninvasive PAP treatment is low.

  11. Continuous Positive Airway Pressure Device Time to Procurement in a Disadvantaged Population

    Directory of Open Access Journals (Sweden)

    Lourdes M. DelRosso

    2015-01-01

    Full Text Available Introduction. The management of obstructive sleep apnea (OSA in patients who cannot afford a continuous positive airway pressure (CPAP device is challenging. In this study we compare time to CPAP procurement in three groups of patients diagnosed with OSA: uninsured subsidized by a humanitarian grant (Group 1, uninsured unsubsidized (Group 2, and those with Medicare or Medicaid (Group 3. We evaluate follow-up and adherence in Group 1. We hypothesize that additional factors, rather than just the ability to obtain CPAP, may uniquely affect follow-up and adherence in uninsured patients. Methods. 30 patients were in Groups 1 and 2, respectively. 12 patients were in Group 3. Time of CPAP procurement from OSA diagnosis to CPAP initiation was assessed in all groups. CPAP adherence data was collected for Group 1 patients at 1, 3, 6, and 9 months. Results. There were no significant differences between groups in gender, age, body mass index, or apnea hypopnea index. The mean time to procurement in Group 1 was shorter compared to Group 2 but not significant. Compared to both Group 1 and Group 2, Group 3 patients had significantly shorter times to device procurement. Conclusion. Time to procurement of CPAP was significantly shorter in those with Medicaid/Medicare insurance compared to the uninsured.

  12. Effects of continuous positive airway pressure on energy balance regulation: a systematic review

    Science.gov (United States)

    Shechter, Ari

    2016-01-01

    Obesity is both a cause and a possible consequence of obstructive sleep apnoea (OSA), as OSA seems to affect parameters involved in energy balance regulation, including food intake, hormonal regulation of hunger/satiety, energy metabolism and physical activity. It is known that weight loss improves OSA, yet it remains unclear why continuous positive airway pressure (CPAP) often results in weight gain. The goal of this systematic review is to explore if and how CPAP affects the behaviour and/or metabolism involved in regulating energy balance. CPAP appears to correct for a hormonal profile characterised by abnormally high leptin and ghrelin levels in OSA, by reducing the circulating levels of each. This is expected to reduce excess food intake. However, reliable measures of food intake are lacking, and not yet sufficient to make conclusions. Although studies are limited and inconsistent, CPAP may alter energy metabolism, with reports of reductions in resting metabolic rate or sleeping metabolic rate. CPAP appears to not have an appreciable effect on altering physical activity levels. More work is needed to characterise how CPAP affects energy balance regulation. It is clear that promoting CPAP in conjunction with other weight loss approaches should be used to encourage optimal outcomes in OSA patients. PMID:27824596

  13. Positive airway pressure improves nocturnal beat-to-beat blood pressure surges in obesity hypoventilation syndrome with obstructive sleep apnea.

    Science.gov (United States)

    Carter, Jason R; Fonkoue, Ida T; Grimaldi, Daniela; Emami, Leila; Gozal, David; Sullivan, Colin E; Mokhlesi, Babak

    2016-04-01

    Positive airway pressure (PAP) treatment has been shown to have a modest effect on ambulatory blood pressure (BP) in patients with obstructive sleep apnea (OSA). However, there is a paucity of data on the effect of PAP therapy on rapid, yet significant, BP swings during sleep, particularly in obesity hypoventilation syndrome (OHS). The present study hypothesizes that PAP therapy will improve nocturnal BP on the first treatment night (titration PAP) in OHS patients with underlying OSA, and that these improvements will become more significant with 6 wk of PAP therapy. Seventeen adults (7 men, 10 women; age 50.4 ± 10.7 years, BMI 49.3 ± 2.4 kg/m(2)) with OHS and clinically diagnosed OSA participated in three overnight laboratory visits that included polysomnography and beat-to-beat BP monitoring via finger plethysmography. Six weeks of PAP therapy, but not titration PAP, lowered mean nocturnal BP. In contrast, when nocturnal beat-to-beat BPs were aggregated into bins consisting of at least three consecutive cardiac cycles with a >10 mmHg BP surge (i.e., Δ10-20, Δ20-30, Δ30-40, and Δ>40 mmHg), titration, and 6-wk PAP reduced the number of BP surges per hour (time × bin, P < 0.05). PAP adherence over the 6-wk period was significantly correlated to reductions in nocturnal systolic (r = 0.713, P = 0.001) and diastolic (r = 0.497, P = 0.043) BP surges. Despite these PAP-induced improvements in nocturnal beat-to-beat BP surges, 6 wk of PAP therapy did not alter daytime BP. In conclusion, PAP treatment reduces nocturnal beat-to-beat BP surges in OHS patients with underlying OSA, and this improvement in nocturnal BP regulation was greater in patients with higher PAP adherence.

  14. Long-Term Effects of Continuous Positive Airway Pressure Treatment on Sexuality in Female Patients with Obstructive Sleep Apnea

    OpenAIRE

    Petersen, Marian; Kristensen, Ellids; Berg, Søren; Midgren, Bengt

    2013-01-01

    Introduction Results from a previous study showed that sexuality was negatively affected in females with untreated obstructive sleep apnea (OSA). Data are sparse on the long-term effects of nocturnal continuous positive airway pressure (CPAP) treatment on sexual difficulties and sexual distress in female patients with OSA. Aim The aim of the present study was to investigate the effects after 1 year of CPAP treatment on sexual difficulties, sexual distress, and manifest sexual dysfunction in f...

  15. The influence of airway supporting maneuvers on glottis view in pediatric fiberoptic bronchoscopy

    Directory of Open Access Journals (Sweden)

    Tarik Umutoglu

    2015-10-01

    Full Text Available ABSTRACTINTRODUCTION:Flexible fiber optic bronchoscopy is a valuable intervention for evaluation and management of respiratory diseases in both infants, pediatric and adult patients. The aim of this study is to investigate the influence of the airway supporting maneuvers on glottis view during pediatric flexible fiberoptic bronchoscopy.MATERIALS AND METHODS:In this randomized, controlled, crossover study; patients aged between 0 and 15 years who underwent flexible fiberoptic bronchoscopy procedure having American Society of Anesthesiologists I---II risk score were included. Patients having risk of difficult intubation, intubated or patients with tracheostomy, and patients with reduced neck mobility or having cautions for neck mobility were excluded from this study. After obtaining best glottic view at the neutral position, patients were positioned jaw trust with open mouth, jaw trust with teeth prottution, head tilt chin lift and triple airway maneuvers and best glottis scores were recorded.RESULTS:Total of 121 pediatric patients, 57 girls and 64 boys, were included in this study. Both jaw trust with open mouth and jaw trust with teeth prottution maneuvers improved the glottis view compared with neutral position (p 0.05. Head tilt chin lift and triple airway maneuvers improved glottis view when compared with both jaw trust with open mouth and jaw trust with teeth prottution maneuvers and neutral position (p 0.05.

  16. Hypoxemia during bilevel positive airway pressure treatment in patients with obstructive sleep apnea syndrome and chronic respiratory insufficiency.

    Science.gov (United States)

    Brzecka, Anna; Piesiak, Pawel; Kosacka, Monika; Jankowska, Renata

    2013-01-01

    In patients with obstructive sleep apnea (OSA) syndrome and chronic respiratory insufficiency one of the options of treatment is bilevel positive airway pressure (BPAP) during sleep. The aim of the study was to find out what are the factors influencing the early results of BPAP treatment in such OSA patients. The study was carried out in 55 adult obese patients (mean body mass index 45 ± 7 kg/m(2)), severe OSA syndrome (mean apnea/hypopnea index 62 ± 19), and chronic respiratory insufficiency (mean PaCO(2) 54 ± 5.7 torr) who underwent polysomnography during BPAP treatment. In 31 patients (56%) the mean SaO(2) during sleep was <88% despite the optimal BPAP and oxygen titration: 83 ± 4% during NREM and 81 ± 7% during REM sleep vs. 91 ± 2% and 90 ± 3%, respectively, in the remaining 24 patients (p < 0.001). The patients with advanced hypoxemia during sleep and BPAP treatment had lower forced vital capacity (2.2 ± 0.9 vs. 2.7 ± 0.8 l, p < 0.05), lower diurnal PaO(2) (49 ± 8 vs. 54 ± 7 torr), higher diurnal PaCO(2) (57 ± 5 vs. 52 ± 5 torr, p < 0.01), and higher PaCO(2) during sleep (75 ± 13 vs. 59.5 ± 7.5 torr). In conclusion, in obese patients with severe OSA syndrome and chronic alveolar hypoventilation there is a risk of sleep hypoxemia during BPAP treatment, despite optimal pressure titration.

  17. Effect of adjuvant nasal continuous positive airway pressure therapy on immune response and organ injury in children with severe pneumonia

    Institute of Scientific and Technical Information of China (English)

    Ni-Na Huang; Yu-Dan Zhang

    2016-01-01

    Objective:To analyze the effect of adjuvant nasal continuous positive airway pressure therapy on immune response and organ injury in children with severe pneumonia.Methods:A total of 90 children with severe pneumonia were randomly divided into observation group and control group (n=45), control group received conventional therapy, observation group accepted regular + adjuvant nasal continuous positive airway pressure therapy, and then differences in immune globulin, Th1/Th2 indexes, blood coagulation indexes, echocardiography parameters and so on were compared between two groups of children.Results:IgG2, IgG3, IgA and IgM content in peripheral blood of observation group were higher than those of control group; Th1/Th2 indexes IL-4 and IFN-γ content in serum as well as IL-4/IFN-γ level were lower than those of control group; blood coagulation indexes PT, TT, APTT and D-D levels were lower than those of control group while FIB and PLT levels were higher than those of control group; echocardiography parameters PVAT and AVAT levels were higher than those of control group while PFVMA level was lower than that of control group.Conclusions: Adjuvant nasal continuous positive airway pressure therapy helps to enhance the immune response and optimize blood coagulation function and cardiac function in children with severe pneumonia.

  18. A pilot study of the effect of pressure-driven lidocaine spray on airway topical anesthesia for conscious sedation intubation

    Institute of Scientific and Technical Information of China (English)

    JIANG Hai; MIAO Hai-sheng; JIN San-qing; CHEN Li-hong; TIAN Jing-ling

    2011-01-01

    Background Difficult airway remains not only a challenge to the anesthesiologists,but also a life-threatening event to the patients.Awake intubation is the principal choice to deal with difficult airway,and a key point for awake intubation is airway topical anesthesia.Yet,so far there is no ideal topical anesthesia approach for awake intubation.This study aimed at evaluating the effect of pressure-driven (by 10 L/min oxygen flow) lidocaine spray on airway topical anesthesia in order to find a powerful and convenient method for airway topical anesthesia for conscious sedation intubation.Methods Thirty adult patients referred for elective surgery under general anesthesia,aged 18-60 years and Mallampati class Ⅰ or Ⅱ,were recruited for the study.Before topical anesthesia,the observer's assessment of alert and sedation (OAA/S) scale was controlled between 3 and 4 by intravenous midazolam (0.03 mg/kg),propofol (2 mg.kg1·h-1) andremifentanil (0.05 μg.kg-1·min-1).Ten minutes after sedation,topical anesthesia was performed with the pressure-driven lidocaine spray; the driving pressure was achieved by an oxygen flow of 10 L/min.After topical anesthesia,tracheal intubation was performed and the intubation condition was assessed with modified the Erhan's intubation condition score by an experienced anesthesiologist,and a score of less than 10 was considered to be satisfactory.Attempts to intubate the patient were recorded,and the complications such as local anesthetic toxicity,mucosa injury,and respiration depression were also recorded.The mean arterial blood pressure (MAP),heart rate (HR) and pulse oxygen saturation (SpO2) were recorded at different time points before and after intubation.Patients were asked 24 hours after the operation whether they could recall the events during intubation.Results All patients were intubated at the first attempt,the average intubation condition score was 7.0±1.1,from 6 to 10,satisfied intubation condition.MAP and HR increased

  19. Efficacy of the addition of positive airway pressure to conventional chest physiotherapy in resolution of pleural effusion after drainage: protocol for a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Elinaldo da Conceição dos Santos

    2015-04-01

    Discussion: Conventional chest physiotherapy and intermittent positive airway pressure breathing are widely indicated for people with pleural effusion and chest drains; however, no studies have evaluated the real benefit of this type of treatment. Our hypothesis is that optimised lung expansion achieved through the application of intermittent positive airway pressure will accelerate the reabsorption of pleural effusion, decrease the duration of chest drainage and respiratory system impairment, reduce the length of hospital stay, and reduce the incidence of pulmonary complications.

  20. Physiological Correlation of Airway Pressure and Transpulmonary Pressure Stress Index on Respiratory Mechanics in Acute Respiratory Failure

    Institute of Scientific and Technical Information of China (English)

    Chun Pan; Lu Chen; Yun-Hang Zhang; Wei Liu; Rosario Urbino; V Marco Ranieri; Hai-Bo Qiu

    2016-01-01

    Background:Stress index at post-recruitment maneuvers could be a method of positive end-expiratory pressure (PEEP) titration in acute respiratory distress syndrome (ARDS) patients.However,airway pressure (Paw) stress index may not reflect lung mechanics in the patients with high chest wall elastance.This study was to evaluate the Paw stress index on lung mechanics and the correlation between Paw stress index and transpulmonary pressure (PL) stress index in acute respiratory failure (ARF) patients.Methods:Twenty-four ARF patients with mechanical ventilation (MV) were consecutively recruited from July 2011 to April 2013 in Zhongda Hospital,Nanjing,China and Ospedale S.Giovanni Battista-Molinette Hospital,Turin,Italy.All patients underwent MV with volume control (tidal volume 6 ml/kg) for 20 min.PEEP was set according to the ARDSnet study protocol.The patients were divided into two groups according to the chest wall elastance/respiratory system elastance ratio.The high elastance group (H group,n =14) had a ratio ≥30%,and the low elastance group (L group,n =10) had a ratio <30%.Respiratory elastance,gas-exchange,Paw stress index,and PL stress index were measured.Student's t-test,regression analysis,and Bland-Altman analysis were used for statistical analysis.Results:Pneumonia was the major cause of respiratory failure (71.0%).Compared with the L group,PEEP was lower in the H group (5.7 ± 1.7 cmH2O vs.9.0 ± 2.3 cm2O,P < 0.01).Compared with the H group,lung elastance was higher (20.0 ± 7.8 cmH2O/L vs.11.6 ± 3.6 cmH2O/L,P < 0.01),and stress was higher in the L group (7.0 ± 1.9 vs.4.9 ± 1.9,P =0.02).A linear relationship was observed between the Paw stress index and the PL stress index in H group (R2 =0.56,P < 0.01) and L group (R2 =0.85,P < 0.01).Conclusion:In the ARF patients with MV,Paw stress index can substitute for PL to guide ventilator settings.

  1. Nasal Expiratory Positive Airway Pressure Devices (Provent) for OSA: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Riaz, Muhammad; Certal, Victor; Nigam, Gaurav; Abdullatif, Jose; Zaghi, Soroush; Kushida, Clete A.; Camacho, Macario

    2015-01-01

    Objective. To quantify the effectiveness of nasal expiratory positive airway pressure (nasal EPAP) devices or Provent as treatment for obstructive sleep apnea (OSA). Methods. PubMed and six other databases were searched through November 15, 2015, without language limitations. Results. Eighteen studies (920 patients) were included. Pre- and post-nasal EPAP means ± standard deviations (M ± SD) for apnea-hypopnea index (AHI) in 345 patients decreased from 27.32 ± 22.24 to 12.78 ± 16.89 events/hr (relative reduction = 53.2%). Random effects modeling mean difference (MD) was −14.78 events/hr [95% CI −19.12, −10.45], p value < 0.00001. Oxygen desaturation index (ODI) in 247 patients decreased from 21.2 ± 19.3 to 12.4 ± 14.1 events/hr (relative reduction = 41.5%, p value < 0.00001). Lowest oxygen saturation (LSAT) M ± SD improved in 146 patients from 83.2 ± 6.8% to 86.2 ± 11.1%, MD 3 oxygen saturation points [95% CI 0.57, 5.63]. Epworth Sleepiness Scale (ESS) M ± SD improved (359 patients) from 9.9 ± 5.3 to 7.4 ± 5.0, MD −2.5 [95% CI −3.2, −1.8], p value < 0.0001. Conclusion. Nasal EPAP (Provent) reduced AHI by 53.2%, ODI by 41.5% and improved LSAT by 3 oxygen saturation points. Generally, there were no clear characteristics (demographic factors, medical history, and/or physical exam finding) that predicted favorable response to these devices. However, limited evidence suggests that high nasal resistance could be associated with treatment failure. Additional studies are needed to identify demographic and polysomnographic characteristics that would predict therapeutic success with nasal EPAP (Provent). PMID:26798519

  2. Accuracy of Positive Airway Pressure Device—Measured Apneas and Hypopneas: Role in Treatment Followup

    Directory of Open Access Journals (Sweden)

    Carl Stepnowsky

    2013-01-01

    Full Text Available Improved data transmission technologies have facilitated data collected from positive airway pressure (PAP devices in the home environment. Although clinicians’ treatment decisions increasingly rely on autoscoring of respiratory events by the PAP device, few studies have specifically examined the accuracy of autoscored respiratory events in the home environment in ongoing PAP use. “PAP efficacy” studies were conducted in which participants wore PAP simultaneously with an Embletta sleep system (Embla, Inc., Broomfield, CO, which was directly connected to the ResMed AutoSet S8 (ResMed, Inc., San Diego, CA via a specialized cable. Mean PAP-scored Apnea-Hypopnea Index (AHI was 14.2 ± 11.8 (median: 11.7; range: 3.9–46.3 and mean manual-scored AHI was 9.4 ± 10.2 (median: 7.7; range: 1.2–39.3. Ratios between the mean indices were calculated. PAP-scored HI was 2.0 times higher than the manual-scored HI. PAP-scored AHI was 1.5 times higher than the manual-scored AHI, and PAP-scored AI was 1.04 of manual-scored AI. In this sample, PAP-scored HI was on average double the manual-scored HI. Given the importance of PAP efficacy data in tracking treatment progress, it is important to recognize the possible bias of PAP algorithms in overreporting hypopneas. The most likely cause of this discrepancy is the use of desaturations in manual hypopnea scoring.

  3. Nasal Expiratory Positive Airway Pressure Devices (Provent for OSA: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Muhammad Riaz

    2015-01-01

    Full Text Available Objective. To quantify the effectiveness of nasal expiratory positive airway pressure (nasal EPAP devices or Provent as treatment for obstructive sleep apnea (OSA. Methods. PubMed and six other databases were searched through November 15, 2015, without language limitations. Results. Eighteen studies (920 patients were included. Pre- and post-nasal EPAP means ± standard deviations (M ± SD for apnea-hypopnea index (AHI in 345 patients decreased from 27.32±22.24 to 12.78±16.89 events/hr (relative reduction = 53.2%. Random effects modeling mean difference (MD was −14.78 events/hr [95% CI −19.12, −10.45], p value < 0.00001. Oxygen desaturation index (ODI in 247 patients decreased from 21.2±19.3 to 12.4±14.1 events/hr (relative reduction = 41.5%, p value < 0.00001. Lowest oxygen saturation (LSAT M ± SD improved in 146 patients from 83.2±6.8% to 86.2±11.1%, MD 3 oxygen saturation points [95% CI 0.57, 5.63]. Epworth Sleepiness Scale (ESS M ± SD improved (359 patients from 9.9±5.3 to 7.4±5.0, MD −2.5 [95% CI −3.2, −1.8], p value < 0.0001. Conclusion. Nasal EPAP (Provent reduced AHI by 53.2%, ODI by 41.5% and improved LSAT by 3 oxygen saturation points. Generally, there were no clear characteristics (demographic factors, medical history, and/or physical exam finding that predicted favorable response to these devices. However, limited evidence suggests that high nasal resistance could be associated with treatment failure. Additional studies are needed to identify demographic and polysomnographic characteristics that would predict therapeutic success with nasal EPAP (Provent.

  4. Significance of depression in obstructive sleep apnea patients and the relationship between the comorbidity and continuous positive airway pressure treatment

    Institute of Scientific and Technical Information of China (English)

    FENG Jing; CHEN Bao-yuan; Ambrose An-Po Chiang

    2010-01-01

    Obstructive sleep apnea (OSA), which is the most common sleep-related breathing disorder and characterized by recurrent collapse of the upper airway,causes repeated arousals from sleep, decreased oxygen saturation of the blood, and excessive daytime sleepiness.Patients with OSA are at increased risk of cardiovascular and cerebrovascular disease, type 2 diabetes, cognitive impairment, and depression.1,2 Currently, continuous positive airway pressure (CPAP) had been identified as the standard treatment for patients with OSA. CPAP shows significant improvements in objective and subjective sleepiness and several quality3 of life assessments, cognitive function and depression.3 However,reports of non-adherence to CPAP therapy range from 29% to 83%, and one of the reasons of non-adherence is the comorbidity of depression.4

  5. Effect of preoperative continuous positive airway pressure duration on outcomes after maxillofacial surgery for obstructive sleep apnoea.

    Science.gov (United States)

    Islam, Shofiq; Taylor, Christopher; Ormiston, Ian W

    2015-02-01

    Continuous positive airway pressure (CPAP) remains the first-line treatment for obstructive sleep apnoea (OSA), and is known to result in various physiological changes. The objective of this study was to evaluate the association between duration of preoperative CPAP therapy and outcome after maxillomandibular advancement (MMA) for OSA. We retrospectively analysed consecutive patients treated at our institution, and divided them into 2 groups based on duration of treatment with CPAP: short-term (up to 12 months) and long-term use (12 months or more). We controlled for baseline demographic and clinical characteristics. We compared postoperative scores for the apnoea/hypopnoea index (AHI) and the Epworth sleepiness scale (ESS), and lowest recorded oxygen saturation between groups. In 43 patients data were available on the preoperative use of CPAP, and in 37 of them preoperative and postoperative polysomnographic data were also available for inclusion. Most had bimaxillary advancement with genioplasty. Differences between the groups in mean reduction in the AHI and lowest oxygen saturation were not significant, and operative success rates were comparable. After operation, the reduction in ESS scores was significantly greater in the long-term group than in the short-term group (mean (SD) 8(3) compared with 2 (2), respectively, p<0.001). Our results suggest that the duration of use of CPAP preoperatively does not significantly influence objective outcome measures. The reduction in AHI scores after MMA was equivalent in both groups. The long-term group seemed to fare better than the short-term group on subjective outcome measures.

  6. Hyaluronic acid influence on platelet-induced airway smooth muscle cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Svensson Holm, Ann-Charlotte B., E-mail: ann-charlotte.svensson@liu.se [Division of Drug Research/Pharmacology, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping University, SE-581 85 Linkoeping (Sweden); Experimental Pathology, Department of Clinical and Experimental Medicine, Linkoeping University, SE-581 85 Linkoeping (Sweden); Bengtsson, Torbjoern [Department of Biomedicine, School of Health and Medical Sciences, Oerebro University, SE-70182 Oerebro (Sweden); Grenegard, Magnus; Lindstroem, Eva G. [Division of Drug Research/Pharmacology, Department of Medical and Health Sciences, Faculty of Health Sciences, Linkoeping University, SE-581 85 Linkoeping (Sweden)

    2012-03-10

    Hyaluronic acid (HA) is one of the main components of the extracellular matrix (ECM) and is expressed throughout the body including the lung and mostly in areas surrounding proliferating and migrating cells. Furthermore, platelets have been implicated as important players in the airway remodelling process, e.g. due to their ability to induce airway smooth muscle cell (ASMC) proliferation. The aim of the present study was to investigate the role of HA, the HA-binding surface receptor CD44 and focal adhesion kinase (FAK) in platelet-induced ASMC proliferation. Proliferation of ASMC was measured using the MTS-assay, and we found that the CD44 blocking antibody and the HA synthase inhibitor 4-Methylumbelliferone (4-MU) significantly inhibited platelet-induced ASMC proliferation. The interaction between ASMC and platelets was studied by fluorescent staining of F-actin. In addition, the ability of ASMC to synthesise HA was investigated by fluorescent staining using biotinylated HA-binding protein and a streptavidin conjugate. We observed that ASMC produced HA and that a CD44 blocking antibody and 4-MU significantly inhibited platelet binding to the area surrounding the ASMC. Furthermore, the FAK-inhibitor PF 573228 inhibited platelet-induced ASMC proliferation. Co-culture of ASMC and platelets also resulted in increased phosphorylation of FAK as detected by Western blot analysis. In addition, 4-MU significantly inhibited the increased FAK-phosphorylation. In conclusion, our findings demonstrate that ECM has the ability to influence platelet-induced ASMC proliferation. Specifically, we propose that HA produced by ASMC is recognised by platelet CD44. The platelet/HA interaction is followed by FAK activation and increased proliferation of co-cultured ASMC. We also suggest that the mitogenic effect of platelets represents a potential important and novel mechanism that may contribute to airway remodelling.

  7. The influence of multilevel upper airway surgery on CPAP tolerance in non-responders to obstructive sleep apnea surgery.

    Science.gov (United States)

    Azbay, Sule; Bostanci, Asli; Aysun, Yasin; Turhan, Murat

    2016-09-01

    The aim of this study was to evaluate the influence of multilevel upper airway surgery on subsequent continuous positive airway pressure (CPAP) use and tolerance in patients with moderate to severe obstructive sleep apnea (OSA). The study cohort enrolled 67 consecutive patients, who underwent septoplasty plus modified uvulopharyngopalatoplasty (mUPPP) with or without modified tongue base suspension (mTBS) due to CPAP intolerance, and who had residual OSA requiring CPAP therapy [non-responders to surgery, apnea-hypopnea index (AHI) >15 events/h] that had been confirmed by control polysomnography at the sixth month postoperatively. A questionnaire including questions on postoperative CPAP use, problems faced during CPAP use after the surgery, change in OSA symptoms, and satisfaction with the surgery was designed, and filled through interviews. Seventeen (25.4 %) patients had septoplasty plus mUPPP and 50 (74.6 %) had septoplasty plus mUPPP combined with mTBS. Postoperatively, mean AHI (45.00 ± 19.76 vs. 36.60 ± 18.34), Epworth sleepiness scale (ESS) score (18.00 ± 4.45 vs. 13.00 ± 4.72), oxygen desaturation index (ODI) (48.98 ± 16.73 vs. 37.81 ± 17.03), and optimal CPAP level (11.80 ± 1.40 vs. 8.96 ± 1.20) were decreased (p CPAP before surgery, almost half (47.8 %) of the cases used CPAP without problems postoperatively. Postoperative CPAP users had significantly higher postoperative AHI (p = 0.001), supine AHI (p = 0.009), ESS (p = 0.019), and ODI (p = 0.014), and significantly lower postoperative minimum O2 saturation (p = 0.001) compared with non-users. Multilevel upper airway surgery with less invasive techniques may improve CPAP tolerance in well-selected patients.

  8. Antigen-induced airway obstruction and the influence of vagus blockade.

    Science.gov (United States)

    Zimmermann, I; Islam, M S; Lanser, K; Ulmer, W T

    1976-01-01

    Respiratory hypersensitivity to Ascaris antigens is carried out on 9 dogs. The participation of vagus reflex on this respiratory distress is studied in 4 of these dogs. The dogs were exposed initially to Ascaris aerosol, then to egg albumin and NaCl aerosol for control, and once more to Ascaris aerosol after bilateral vagi blockade and lavage, respectively. The principal parameters studied were deltaPoes (mm Hg)/100 ml TV as a measurement of flow resistance in the airways, and respiratory rates (Poes=changes of oesphagus pressure; TV=tidal volume). All the animals presented a significant respiratory distress with Ascaris aerosol, which could be clearly avoided with the central bilateral blockade of nervus vagus.

  9. Continuous Positive Airway Pressure Therapy for Obstructive Sleep Apnea: Maximizing Adherence Including Using Novel Information Technology-based Systems.

    Science.gov (United States)

    Hevener, Bretton; Hevener, William

    2016-09-01

    Sleep apnea is a form of sleep-disordered breathing that is associated with an increase in disease comorbidities, mortality risks, health care costs, and traffic accidents. Sleep apnea is most commonly treated with positive airway pressure (PAP). PAP can be difficult for patients to tolerate. This leads to initial and long-term noncompliance. Most insurance companies require compliance with PAP treatment to cover ongoing reimbursements for the device and related disposable supplies. Therefore, there are both clinical and financial incentives to a sleep apneic patient's compliance with PAP therapy.

  10. Efficacy of the New Perilaryngeal Airway (CobraPLA™) Versus the Laryngeal Mask Airway (LMA™) to Improve Oropharyngeal Leak Pressure in Obese and Overweight Patients

    NARCIS (Netherlands)

    Yaghoobi, Siamak; Abootorabi, Seyed Mohamadreza; Kayalha, Hamid; Van Zundert, Tom C; Pakpour, Amir H

    2015-01-01

    BACKGROUND: This study aimed to evaluate the applicability of Cobra perilaryngeal airway (Cobra PLA™) for obese patients under general anesthesia and also to compare the results with those of classic laryngeal mask airway (LMA™). MATERIALS AND METHODS: Seventy-three overweight and obese patients wer

  11. Influences of the breathing route on upper airway dynamics properties in normal awake subjects with constant mouth opening.

    Science.gov (United States)

    Wang, Wei; Verin, Eric; Sériès, Frédéric

    2006-11-01

    MB (mouth breathing) promotes the occurrence of sleep-disordered breathing even in non-apnoeic subjects. Considering that MO (mouth opening) contributes to an increase in UA (upper airway) collapsibility independently of MB, the aim of the present study was to assess the influence of breathing route on UA dynamics in the presence of MO. Bilateral anterior magnetic phrenic nerve stimulation was performed 2 s after expiratory onset in 12 healthy male subjects during wakefulness (age, 50+/-5 years; body mass index, 27.8+/-2.4 kg/m(2)) during MB through a mouthpiece and during exclusive NB (nasal breathing) with the same mouthpiece in place. Twitch-induced V(I) (instantaneous flow), P(ph) and P(es) (pharyngeal and oesophageal pressures respectively) were recorded and the corresponding resistances were measured. A polynomial regression model, V(I)=k(1)P(d)+k(2)P(d)(2), was used to characterize flow-pressure relationship and to determine the P(d) value at which UA collapses. There was no difference in UA dynamic properties between NB and MB when UA collapse occurred above the pharyngeal catheter. For twitches where UA collapse occurred lower in the UA, pharyngeal resistance decreased from NB to MB (2.0+/-0.3 and 1.5+/-0.2 cmH(2)Oxl(-1)xs respectively; P=0.02; values are means+/-S.D.), whereas closing pressure increased (-25.7+/-10.1 and -18.0+/-3.0 cmH(2)O respectively; P=0.04). We conclude that (i) in the presence of MO the dynamic properties of the proximal UA free of phasic activity do not differ between NB and MB, and (ii) MB decreases the upstream resistance and increases collapsibility of the distal UA.

  12. EXTUBATE: A randomised controlled trial of nasal biphasic positive airway pressure vs. nasal continuous positive airway pressure following extubation in infants less than 30 weeks' gestation: study protocol for a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Victor Suresh

    2011-12-01

    Full Text Available Abstract Background Respiratory distress syndrome remains a significant problem among premature infants. Mechanical ventilation through an endotracheal tube remains the mainstay of respiratory support but may be associated with lung injury and the development of chronic lung disease of prematurity. Efforts are needed to reduce the duration of mechanical ventilation in favour of less invasive forms of respiratory support and to improve rates of successful extubation. Non-invasive respiratory support has been demonstrated to be less injurious to the premature lung. Standard practice is to use nasal continuous positive airway pressure (n-CPAP following extubation to support the baby's breathing. Many clinicians also use nasal biphasic positive airway pressure (n-BiPAP in efforts to improve rates of successful extubation. However, there is currently no evidence that this confers any advantage over conventional nasal continuous positive airway pressure. Methods We propose an unblinded multi-centre randomised trial comparing n-CPAP with n-BiPAP in babies born before 30 weeks' gestation and less than two weeks old. Babies with congenital abnormalities and severe intra-ventricular haemorrhage will be excluded. 540 babies admitted to neonatal centres in England will be randomised at the time of first extubation attempt. The primary aim of this study is to compare the rate of extubation failure within 48 hours following the first attempt at extubation. The secondary aims are to compare the effect of n-BiPAP and n-CPAP on the following outcomes: 1. Maintenance of successful extubation for 7 days post extubation 2. Oxygen requirement at 28 days of age and at 36 weeks' corrected gestational age 3. Total days on ventilator, n-CPAP/n-BiPAP 4. Number of ventilator days following first extubation attempt 5. pH and partial pressure of carbon dioxide in the first post extubation blood gas 6. Duration of hospital stay 7. Rate of abdominal distension requiring

  13. Influence of radiation dose and reconstruction algorithm in MDCT assessment of airway wall thickness: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Cardona, Daniel [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Nagle, Scott K. [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Department of Pediatrics, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Li, Ke; Chen, Guang-Hong, E-mail: gchen7@wisc.edu [Department of Medical Physics, University of Wisconsin-Madison School of Medicine and Public Health, 1111 Highland Avenue, Madison, Wisconsin 53705 (United States); Department of Radiology, University of Wisconsin-Madison School of Medicine and Public Health, 600 Highland Avenue, Madison, Wisconsin 53792 (United States); Robinson, Terry E. [Department of Pediatrics, Stanford School of Medicine, 770 Welch Road, Palo Alto, California 94304 (United States)

    2015-10-15

    levels. For FBP, the relative bias and the angular standard deviation of the measured WT increased steeply with decreasing radiation dose. Except for the smallest airway, MBIR enabled significant reduction in both the relative bias and angular standard deviation of the WT, particularly at low radiation dose levels; the SSQ was reduced by 50%–96% by using MBIR. The optimal reconstruction algorithm was found to be MBIR for the seven airways being assessed, and the combined use of MBIR and optimal kV–mAs selection resulted in a radiation dose reduction of 37%–83% compared with a reference scan protocol with a dose level of 1 mGy. Conclusions: The quantification accuracy of airway WT is strongly influenced by radiation dose and reconstruction algorithm. The MBIR algorithm potentially allows the desired WT quantification accuracy to be achieved with reduced radiation dose, which may enable a wider clinical use of MDCT for the assessment of airway WT, particularly for younger patients who may be more sensitive to exposures with ionizing radiation.

  14. Unilateral pulmonary oedema due to lung re-expansion following pleurocentesis for spontaneous pneumothorax. The role of non-invasive continuous positive airway pressure ventilation.

    Science.gov (United States)

    Papakonstantinou, Dimitrios K; Gatzioufas, Zisis I; Tzegas, Georgios I; Stergiopoulos, Panagiotis I; Tsokantaridis, Christos G; Chalikias, Georgios K; Tziakas, Dimitrios N

    2007-01-18

    Re-expansion pulmonary oedema represents a rare complication of treatment of spontaneous pneumothorax with only a few cases documented in the current literature. We present the case of a 47-year-old male who presented a right-sided spontaneous pneumothorax and developed respiratory failure after chest tube drainage. The diagnosis of re-expansion pulmonary oedema was made and he was successfully treated with non-invasive continuous positive airway pressure ventilation. Since pathogenesis of re-expansion unilateral pulmonary oedema differs significantly from that of cardiogenic pulmonary oedema, the role of non-invasive continuous positive airway pressure ventilation is discussed as an additional therapeutic option.

  15. Airway distensibility in Chronic Obstructive Airway Disease

    DEFF Research Database (Denmark)

    Winkler Wille, Mathilde Marie; Pedersen, Jesper Holst; Dirksen, Asger

    2013-01-01

    -20% (mild), 20%-30% (moderate) or >30% (severe). Spirometry was performed annually and participants were divided into severity groups according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD). Data were analysed in a mixed effects regression model with log(airway lumen diameter......Rationale – Chronic Obstructive Pulmonary Disease (COPD) is a combination of chronic bronchitis and emphysema, which both may lead to airway obstruction. Under normal circumstances, airway dimensions vary as a function of inspiration level. We aim to study the influence of COPD and emphysema...... in causing airway narrowing, the latter most likely due to loss of elastic recoil of surrounding tissue....

  16. [Continuous positive airway pressure and high-frequency independent lung ventilation in patients with chronic obstructive lung diseases].

    Science.gov (United States)

    Fedorova, E A; Vyzhigina, M A; Gal'perin, Iu S; Zhukova, S G; Titov, V A; Godin, A V

    2004-01-01

    The original hypoxemia, hypercapnia, high pulmonary hypertension, high resistance of microcirculation vessels, right volumetric ventricular overload, persistent sub-edema of pulmonary intersticium as well as disparity of ventilation and perfusion between both lungs are the main problems in patients with chronic obstructive disease of the lungs (CODL). Such patients are, as a rule, intolerant to the independent lung collaboration or artificial single-stage ventilation (ASV). Patients with respiratory insufficiency, stages 2 and 3, and with a pronounced impaired type of ventilation have originally a deranged blood gas composition, like hypoxemia or hypercapnia. The application of volume-controllable bi-pulmonary ASV in such patients maintains an adequate gas exchange hemodynamics. However, ASV is accompanied by a significantly reduced gas-exchange function of the single ventilated lung and by essentially worsened intrapulmonary hemodynamics. Therefore, what is needed is to use alternative methods of independent lung ventilation in order to eliminate the gas-exchange impairments and to enable surgical interventions at thoracic organs in such patients (who are intolerant to ASV). A choice of a method and means of oxygen supply to the independent lung is of great importance. The possibility to avoid a high pressure in the airways, while maintaining, simultaneously, an adequate gas exchange, makes the method related with maintaining a constant positive pressure in the airways (CPPA) a priority one in case of CODL patients. The use of constant high-frequency ventilation in the independent lung in patients with obstructive pulmonary lesions does not improve the gas exchange or hemodynamics. Simultaneously, a growing total pulmonary resistance and an increasing pressure in the pulmonary artery are observed. Consequently, the discussed method must not be used for the ventilation support of the independent lung in patients with the obstructive type of the impaired external

  17. Gut microbiota metabolism of dietary fiber influences allergic airway disease and hematopoiesis.

    Science.gov (United States)

    Trompette, Aurélien; Gollwitzer, Eva S; Yadava, Koshika; Sichelstiel, Anke K; Sprenger, Norbert; Ngom-Bru, Catherine; Blanchard, Carine; Junt, Tobias; Nicod, Laurent P; Harris, Nicola L; Marsland, Benjamin J

    2014-02-01

    Metabolites from intestinal microbiota are key determinants of host-microbe mutualism and, consequently, the health or disease of the intestinal tract. However, whether such host-microbe crosstalk influences inflammation in peripheral tissues, such as the lung, is poorly understood. We found that dietary fermentable fiber content changed the composition of the gut and lung microbiota, in particular by altering the ratio of Firmicutes to Bacteroidetes. The gut microbiota metabolized the fiber, consequently increasing the concentration of circulating short-chain fatty acids (SCFAs). Mice fed a high-fiber diet had increased circulating levels of SCFAs and were protected against allergic inflammation in the lung, whereas a low-fiber diet decreased levels of SCFAs and increased allergic airway disease. Treatment of mice with the SCFA propionate led to alterations in bone marrow hematopoiesis that were characterized by enhanced generation of macrophage and dendritic cell (DC) precursors and subsequent seeding of the lungs by DCs with high phagocytic capacity but an impaired ability to promote T helper type 2 (TH2) cell effector function. The effects of propionate on allergic inflammation were dependent on G protein-coupled receptor 41 (GPR41, also called free fatty acid receptor 3 or FFAR3), but not GPR43 (also called free fatty acid receptor 2 or FFAR2). Our results show that dietary fermentable fiber and SCFAs can shape the immunological environment in the lung and influence the severity of allergic inflammation.

  18. The Effect of Nasal Surgery on Continuous Positive Airway Pressure Device Use and Therapeutic Treatment Pressures: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Camacho, Macario; Riaz, Muhammad; Capasso, Robson; Ruoff, Chad M.; Guilleminault, Christian; Kushida, Clete A.; Certal, Victor

    2015-01-01

    Background: The relationship between nasal surgery and its effect on continuous positive airway pressure (CPAP) device therapeutic treatment pressures and CPAP device use has not been previously systematically examined. Study Objectives: To conduct a systematic review and meta-analysis evaluating the effect of isolated nasal surgery on therapeutic CPAP device pressures and use in adults with obstructive sleep apnea. Methods: MEDLINE, Scopus, Web of Science, and The Cochrane Library were searched through July 15, 2014. The MOOSE consensus statement and PRISMA statement were followed. Results: Eighteen studies (279 patients) reported CPAP data after isolated nasal surgery. Seven studies (82 patients) reported preoperative and postoperative mean therapeutic CPAP device pressures and standard deviations, which reduced from 11.6 ± 2.2 to 9.5 ± 2.0 centimeters of water pressure (cwp) after nasal surgery. Pooled random effects analysis demonstrated a statistically significant pressure reduction, with a mean difference of −2.66 cwp (95% confidence intervals, −3.65 to −1.67); P < 0.00001. Eleven studies (153 patients) described subjective, self-reported data for CPAP use; and a subgroup analysis demonstrated that 89.1% (57 of 64 patients) who were not using CPAP prior to nasal surgery subsequently accepted, adhered to, or tolerated it after nasal surgery. Objective, device meter-based hours of use increased in 33 patients from 3.0 ± 3.1 to 5.5 ± 2.0 h in the short term (< 6 mo of follow-up). Conclusion: Isolated nasal surgery in patients with obstructive sleep apnea and nasal obstruction reduces therapeutic CPAP device pressures and the currently published literature's objective and subjective data consistently suggest that it also increases CPAP use in select patients. Citation: Camacho M, Riaz M, Capasso R, Ruoff CM, Guilleminault C, Kushida CA, Certal V. The effect of nasal surgery on continuous positive airway pressure device use and therapeutic treatment

  19. Measurement of Pressure between Upper Airway Tract and Laryngoscope Blade during Orotracheal Intubation with Film of Microcapsules

    Directory of Open Access Journals (Sweden)

    Shigehiro Hashimoto

    2014-04-01

    Full Text Available The measurement system for the pressure between the blade of a laryngoscope and the upper airway tract during orotracheal intubation has been investigated with a film of microcapsules. Two types of the laryngoscope were used in the study: Wis-Foregger and Mac-Intosh. The film is attached on the surface of the blade of the laryngoscope. The measurement was applied to 20 cases of the orotracheal intubation. In the pressed part of the film, the microcapsules burst and release chemicals, which react with chemicals out of microcapsules and show a red color. The color density was photoelectrically measured, and converted to the pressure value in three regions on the blade; the epiglottis, the tongue, and the upper incisor. The results show that the pressures are 1.2±0.6 MPa on the epiglottis, 0.8±0.4 MPa on the tongue, and (11±3×10 MPa on the upper incisor, and that the pressures on the epiglottis are 2.0±0.3 MPa in bled cases, and 0.8±0.4 MPa in non-bled cases.

  20. The Efficacy of a Protocolized Nursing Care on Nasal Skin Breakdown in Preterm Neonates Receiving Nasal Continuous Positive Airway Pressure

    Directory of Open Access Journals (Sweden)

    Mahnaz Jabraeili

    2017-01-01

    Full Text Available Background: Nasal continuous positive airway pressure (NCPAP is an effective method of ventilation in newborns with respiratory distress syndrome (RDS. Using an appropriate nasal skin care protocol is identical to prevention or reduction of nasal skin breakdown in those who receive NCPAP. This study aimed to investigate the effectiveness of an evidence-based clinical care protocol on nasal skin integrity in preterm newborns who receive NCPAP.Materials and Methods: A Randomized Controlled Trial was used to conduct the study. A cohort of 110 preterm newborns with a gestational age (GA of 25 to 36 weeks, receiving nasal continuous positive airway pressure (NCPAP for RDS in the neonatal intensive care unit of a university teaching hospital were selected to perform the study. They were randomly assigned to a protocolized nasal skin care (group A or to a group receiving the routine care (group B. Nasal skin integrity of the preterm neonates, were measured on a daily basis for 10 days using the Neonatal Skin Condition Scale (NSCS 24 hours after placement of NCPAPs in both groups.Results: Each intervention and control group included 55 neonates. 65.50% of neonates in the control group and 47.30% of neonates in the intervention group were male. Repeated measures analysis showed thatNSCS scores were significantly lower in intervention group receiving nasal skin care in accordance with the protocol than the control group receiving the routine nasal skin care (P=0.000. Conclusion: In this study, the protocolized care reduced nasal skin breakdown in the preterm newborns receiving NCPAP. Therefore, it can be used as an effective method in nasal skin care in neonates who are treated by NCPAP.

  1. Sexual function and obstructive sleep apnea-hypopnea : A randomized clinical trial evaluating the effects of oral-appliance and continuous positive airway pressure therapy

    NARCIS (Netherlands)

    Hoekema, Aarnoud; Stel, Anna-Lucia; Stegenga, Boudewijn; van der Hoeven, Johannes H.; Wijkstra, Peter J.; van Driel, Mels F.; de Bont, Lambert G. M.

    2007-01-01

    Introduction. The obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with sexual dysfunction. Although successful treatment with continuous positive airway pressure (CPAP) has been demonstrated to improve sexual function, the effects of oral-appliance therapy are unknown. Aim. The aims

  2. Effect of Positive Airway Pressure on Cardiovascular Outcomes in Coronary Artery Disease Patients with Non-Sleepy Obstructive Sleep Apnea : The RICCADSA Randomized Controlled Trial

    NARCIS (Netherlands)

    Peker, Yüksel; Glantz, Helena; Eulenburg, Christine; Wegscheider, Karl; Herlitz, Johan; Thunström, Erik

    2016-01-01

    RATIONALE: Obstructive sleep apnea is common in patients with coronary artery disease, many of whom do not report daytime sleepiness. First-line treatment for symptomatic obstructive sleep apnea is continuous positive airway pressure, but its value in patients without daytime sleepiness is uncertain

  3. A 64-year old man who sustained many episodes of acute cardiogenic pulmonary edema successfully treated with Boussignac continuous positive airway pressure : A case report

    NARCIS (Netherlands)

    Dieperink, Willem; van der Horst, Iwan C. C.; Nannenberg-Koops, Jaqueline W.; Brouwer, Henk W.; Jaarsma, T.; Nieuwland, Wybe; Zijlstra, Felix; Nijsten, Maarten W. N.

    2007-01-01

    Continuous positive airway pressure (CPAP) is standard treatment for patients with acute cardiogenic pulmonary edema. We describe a patient who had 21 episodes of acute cardiogenic pulmonary edema due to very poor patient compliance. This 64-year old man had end-stage congestive heart failure based

  4. Effect of continuous positive airway pressure treatment on pulmonary artery pressure in patients with isolated obstructive sleep apnea: a meta-analysis.

    Science.gov (United States)

    Imran, Tasnim F; Ghazipura, Marya; Liu, Spencer; Hossain, Tanzib; Ashtyani, Hormoz; Kim, Bernard; Michael Gaziano, J; Djoussé, Luc

    2016-09-01

    Pulmonary hypertension (PH) can occur in patients with obstructive sleep apnea (OSA) in the absence of cardiac or lung disease. Data on the development and severity of PH, and the effect of continuous positive airway pressure (CPAP) therapy on pulmonary artery (PA) pressures in these patients have been inconsistent in the literature. We sought to determine whether CPAP therapy affects PA pressures in patients with isolated OSA in this meta-analysis. We searched PubMed, Medline, EMBASE and other databases from January 1980 to August 2015. Studies of patients with OSA, defined as an apnea-hypopnea index >10 events/h, and PH, defined as PA pressure >25 mmHg were included. Two reviewers independently extracted data and assessed risk of bias. A total of 222 patients from seven studies (341.53 person-years) had reported PA pressures before and after treatment with CPAP therapy. 77 % of participants were men, with a mean age of 52.5 years, a mean apnea-hypopnea index of 58 events/h, and mean PA pressure of 39.3 ± 6.3 mmHg. CPAP treatment duration ranged from 3 to 70 months. Using fixed effects meta-analysis, CPAP therapy was associated with a decrease in PA pressure of 13.3 mmHg (95 % CI 12.7-14.0) in our study population. This meta-analysis found that CPAP therapy is associated with a significantly lower PA pressure in patients with isolated OSA and PH.

  5. Inductance plethysmography: an alternative signal to servocontrol the airway pressure during proportional assist ventilation in small animals.

    Science.gov (United States)

    Schulze, A; Suguihara, C; Gerhardt, T; Schaller, P; Claure, N; Everett, R; Devia, C; Hehre, D; Bancalari, E

    2001-02-01

    During proportional assist ventilation (PAV), the ventilator pressure is servocontrolled throughout each spontaneous inspiration such that it instantaneously increases in proportion to the airflow (resistive unloading mode), or inspired volume (elastic unloading mode), or both (combined unloading mode). The PAV pressure changes are generated in a closed-loop feedback circuitry commonly using a pneumotachographic signal. In neonates, however, a pneumotachograph increases dead space ventilation, and its signal may include a substantial endotracheal tube leak component. We hypothesized that respiratory inductive plethysmography (RIP) can replace pneumotachography to drive the ventilator during PAV without untoward effects on ventilation or respiratory gas exchange. Ten piglets and five rabbits were supported for 10-min (normal lungs) or 20-min (meconium injured lungs) periods by each of the three PAV modes. In each mode, three test periods were applied in random order with the ventilator driven by the pneumotachograph signal, or the RIP abdominal band signal, or the RIP sum signal of rib cage and abdomen. Interchanging the three input signals did not affect the regularity of spontaneous breathing, and gas exchange was achieved with similar peak and mean airway pressures (ANOVA). However, the RIP sum signal worked adequately only when the relative gains of rib cage and abdominal band signal were calibrated. We conclude that an RIP abdominal band signal can be used to generate PAV, avoiding increased dead space and endotracheal tube leak problems.

  6. Cervical computed tomography in patients with obstructive sleep apnea: influence of head elevation on the assessment of upper airway volume

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Fabio Jose Fabricio de Barros; Evangelista, Anne Rosso; Silva, Juliana Veiga; Madeira, Kristian, E-mail: fsouzapneumo@hotmail.com [Universidade do Extremo Sul Catarinense (UNESC), Criciuma, SC (Brazil). Curso de Medicina; Perico, Gregory Vinicius [Unidade Radiologica Criciuma, SC (Brazil)

    2016-01-15

    Objective: Obstructive sleep apnea syndrome (OSAS) has a high prevalence and carries significant cardiovascular risks. It is important to study new therapeutic approaches to this disease. Positional therapy might be beneficial in reducing the apnea-hypopnea index (AHI). Imaging methods have been employed in order to facilitate the evaluation of the airways of OSAS patients and can be used in order to determine the effectiveness of certain treatments. This study was aimed at determining the influence that upper airway volume, as measured by cervical CT, has in patients diagnosed with OSAS. Methods: This was a quantitative, observational, cross-sectional study. We evaluated 10 patients who had been diagnosed with OSAS by polysomnography and on the basis of the clinical evaluation. All of the patients underwent conventional cervical CT in the supine position. Scans were obtained with the head of the patient in two positions (neutral and at a 44° upward inclination), and the upper airway volume was compared between the two. Results: The mean age, BMI, and neck circumference were 48.9 ± 14.4 years, 30.5 ± 3.5 kg/m{sup 2} , and 40.3 ± 3.4 cm, respectively. The mean AHI was 13.7 ± 10.6 events/h (range, 6.0-41.6 events/h). The OSAS was classified as mild, moderate, and severe in 70%, 20%, and 10% of the patients, respectively. The mean upper airway volume was 7.9 cm{sup 3} greater when the head was at a 44° upward inclination than when it was in the neutral position, and that difference (17.5 ± 11.0%) was statistically significant (p = 0.002). Conclusions: Elevating the head appears to result in a significant increase in the caliber of the upper airways in OSAS patients. (author)

  7. Cervical computed tomography in patients with obstructive sleep apnea: influence of head elevation on the assessment of upper airway volume

    Science.gov (United States)

    Souza, Fábio José Fabrício de Barros; Evangelista, Anne Rosso; Silva, Juliana Veiga; Périco, Grégory Vinícius; Madeira, Kristian

    2016-01-01

    Objective : Obstructive sleep apnea syndrome (OSAS) has a high prevalence and carries significant cardiovascular risks. It is important to study new therapeutic approaches to this disease. Positional therapy might be beneficial in reducing the apnea-hypopnea index (AHI). Imaging methods have been employed in order to facilitate the evaluation of the airways of OSAS patients and can be used in order to determine the effectiveness of certain treatments. This study was aimed at determining the influence that upper airway volume, as measured by cervical CT, has in patients diagnosed with OSAS. Methods : This was a quantitative, observational, cross-sectional study. We evaluated 10 patients who had been diagnosed with OSAS by polysomnography and on the basis of the clinical evaluation. All of the patients underwent conventional cervical CT in the supine position. Scans were obtained with the head of the patient in two positions (neutral and at a 44° upward inclination), and the upper airway volume was compared between the two. Results : The mean age, BMI, and neck circumference were 48.9 ± 14.4 years, 30.5 ± 3.5 kg/m2, and 40.3 ± 3.4 cm, respectively. The mean AHI was 13.7 ± 10.6 events/h (range, 6.0-41.6 events/h). The OSAS was classified as mild, moderate, and severe in 70%, 20%, and 10% of the patients, respectively. The mean upper airway volume was 7.9 cm3 greater when the head was at a 44° upward inclination than when it was in the neutral position, and that difference (17.5 ± 11.0%) was statistically significant (p = 0.002). Conclusions : Elevating the head appears to result in a significant increase in the caliber of the upper airways in OSAS patients. PMID:26982042

  8. A comparison of intraocular pressure and hemodynamic responses to insertion of laryngeal mask airway or endotracheal tube using anesthesia with propofol and remifentanil in cataract surgery

    Directory of Open Access Journals (Sweden)

    Mohsen Ziyaeifard

    2012-01-01

    Full Text Available Background: The aim of this study was to evaluate intraocular pressure (IOP and hemodynamic responses following insertion of laryngeal mask airway (LMA or endotracheal tube (ETT after anesthesia induction with propofol and remifentanil in cataract surgery. Materials and Methods: In a randomized controlled study, 50 adults scheduled for elective cataract extraction procedure under general anesthesia were allocated to LMA insertion (n = 25 or ETT (n = 25 groups. IOP, systolic blood pressure (SBP, diastolic blood pressure (DBP, and heart rate (HR were measured after insertion of the airway device every minute up to 5 min. Results: There were no significant differences between LMA and ETT groups in SBP, DBP, HR, and IOP immediately after airway instrumentation up to 5 min, except in 4th min in DBP, 2nd min in HR, and 5th min in IOP (7.9 ± 2.3 mmHg in LMA and 9.4 ± 2.5 mmHg in ETT group; P = 0.030. There was good surgeon satisfaction for providing acceptable surgical field in both groups (88% in LMA and 80% in ETT group; P = 0.702. Conclusion: Propofol combined with remifentanil provides good and excellent conditions for insertion of LMA or ETT with minimal hemodynamic disturbances in cataract surgery. Considering LMA insertion is less traumatic than ETT, using LMA may be better than ETT for airway securing in these patients.

  9. Effect of ethanol on the efficacy of nasal continuous positive airway pressure as a treatment for obstructive sleep apnea.

    Science.gov (United States)

    Berry, R B; Desa, M M; Light, R W

    1991-02-01

    The effect of ethanol ingestion on the efficacy of nasal continuous positive airway pressure (nasal CPAP) as a treatment for the obstructive sleep apnea (OSA) syndrome was studied in ten obese male subjects undergoing this therapy. On the first night of polysomnography, the lowest level of CPAP that maintained airway patency was determined (critical level). On the second (control) night (C), subjects slept the entire night on this level of CPAP. On the third night (E), subjects ingested either 1.5 ml/kg (part A, N = 6) or 2.0 ml/kg (part B, N = 4) of 50 percent ethanol (100 proof vodka) over one half-hour starting 1 h before bedtime. A serum ethanol level was obtained at bedtime (part A: 63.7 +/- 17.3 mg/dl; part B: 108.6 +/- 20.6 mg/dl), and subjects were monitored on the critical level of CPAP. Comparison of nights C and E for parts A + B showed no difference in total sleep time (TST) or the amount of different sleep stages as an absolute time or a percentage of TST except that there was more stage 2 (as a percent of TST) on E nights. The apnea + hypopnea index and C and E nights did not differ and was quite low (3.6 +/- 3.7/h vs 1.9 +/- 2.7/h). Similarly, ethanol ingestion did not increase the number of desaturations to at or below 90 and 85 percent, or lower the mean arterial oxygen saturation in NREM or REM sleep. Analysis of parts A and B separately also showed no differences with respect to the apnea + hypopnea index or the number of desaturations on control and ethanol nights. We conclude that acute moderate ethanol ingestion does not decrease the efficacy of an optimum level of nasal CPAP.

  10. 电话随访对阻塞性睡眠呼吸暂停综合征患者使用正压通气依从性的影响%Influence of follow-up by telephone on rehabilitation compliance of obstructive sleep apnea syndrome patients treated with continuous positive airway pressure

    Institute of Scientific and Technical Information of China (English)

    孙龙凤; 孔德磊; 王爱平

    2012-01-01

    Objective Research the follow-up effect for the compliance of obstructive sleep apnea syndrome(OSAHS) patients treated with nasal continuous positive airway pressure (CPAP) by telephone. Methods Divide sixty OSAHS patients treated with CPAP into observation groups and control group. Both groups have 30 patients. The patients in control group were carried on routing guidance treatment and enjoined regular subsequent visit. The patients in observation group were carried on the above-mentioned treatment and also receive regular follow-up by telephone. Through the follow-up by telephone we provided guidance for present and will-present problems. Then we compared the EPWorth sleepiness scale (ESS) and status of using breathing machine before and after half of year. Results The apnea hyponea index (AHI) and average air leakage of patients in observation group were lower than those in control group. The average total days,average actual using days and percentage of treatment time higher than 4 hours in using days in the observation group were higher than the control group. Conclusions The follow-up by telephone can improve the compliance of the OSAHS patients with treatment of CPAP and reduce the medical burden.%目的 探讨电话随访对阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者使用经鼻持续正压通气(CPAP)治疗依从性的干预效果.方法 将60例使用CPAP治疗的OSAHS患者分为观察组和对照组各30例,观察组在常规治疗指导、嘱其定期复诊的基础上,定期电话随访,对患者在治疗期间出现的和可能出现的问题进行指导.对照组行常规治疗指导,嘱其定期复诊;两组接受CPAP治疗前和治疗后6个月进行嗜睡评分及呼吸机使用情况比较.结果 观察组的呼吸紊乱指数(AHI)、平均漏气量低于对照组,观察组的使用天数及使用天数的平均使用时间、使用天数治疗时间>4h、最低氧饱和度(LSAT)均高于对照组.结论 电话随访能有

  11. Influence of continuous positive airway pressure on N-terminal pro-B-type natriuretic peptide in non-obese patients with obstructive sleep apnea%持续正压通气对阻塞性睡眠呼吸暂停非肥胖者的氨基末端B型利钠肽原水平的影响

    Institute of Scientific and Technical Information of China (English)

    邱志辉; 陆冬晓

    2016-01-01

    目的:探讨持续正压通气(CPAP)对阻塞性睡眠呼吸暂停(OSA)非肥胖者的血清氨基末端B型利钠肽原(NT‐proB‐NP)水平的影响。方法选择41例重度OSA合并有冠心病(CAD)的患者,根据患者体质量指数(BMI)分为肥胖组(BMI>28 kg/m2)和非肥胖组(BMI≤28 kg/m2),所有患者均接受24周的CPAP治疗。采用电化学发光法测定NT‐proBNP水平,比较治疗前后NT‐proBNP水平的变化。结果非肥胖组患者治疗后的NT‐proBNP平均水平出现明显下降,从治疗前(141.8±156.5) pg/mL下降到(106.7±167.2)pg/mL ,治疗前后比较差异有统计学意义(P<0.05);肥胖组患者治疗后的NT‐proBNP平均水平出现升高的趋势,从治疗前(32.2±24.5)pg/mL 升高到(86.3±174.4)pg/mL ,治疗前后比较差异无统计学意义(P>0.05)。结论 CPAP能有效降低重度OSA合并CAD非肥胖者的NT‐proBNP水平。%Objective To explore the effects of continuous positive airway pressure (CPAP) on N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) in the non‐obese patients with obstructive sleep apnea (OSA) .Methods A total of 41 cases of severe OSA complicating coronary artery disease(CAD) were divided into two groups based on their body mass index (BMI):obese group (BMI>28 kg/m2 ) and non‐obese group (BMI≤28 kg/m2 ) .All the patients were treated by CPAP for 24 weeks .Serum NT‐proBNP lev‐el was detected by adopting the electrochemiluminescence method ,the changes of the serum levels of NT‐proBNP were compared between before and after treatment .Results The NT‐proBNP level after treatment in the non‐obese group was significantly de‐creased ,which was decreased from (141 .8 ± 156 .5)pg/mL before treatment to (106 .7 ± 167 .2)pg/mL ,the difference was statisti‐cally significant (P0 .05) .Conclusion CPAP can effectively decrease the NT‐proBNP level in non

  12. Nasal pillows as an alternative interface in patients with obstructive sleep apnoea syndrome initiating continuous positive airway pressure therapy.

    LENUS (Irish Health Repository)

    Ryan, Silke

    2012-02-01

    Side-effects directly due to the nasal mask are common in patients with obstructive sleep apnoea syndrome (OSAS) commencing continuous positive airway pressure (CPAP). Recently, nasal pillows have been designed to overcome these issues. Limited evidence exists of the benefits and effectiveness of these devices. Twenty-one patients (19 male, 49+\\/-10years) with the established diagnosis of OSAS [apnoea\\/hypopnoea index (AHI): 52+\\/-22] and who had a successful CPAP titration were commenced on CPAP therapy (10+\\/-2cmH2O), and randomized to 4weeks of a nasal pillow (P) and a standard nasal mask (M) in a crossover design. Outcome measures were objective compliance, AHI, quality of life, Epworth Sleepiness Score (ESS) and CPAP side-effects. There was no difference in compliance (M versus P: 5.1+\\/-1.9h versus 5.0+\\/-1.7h; P=0.701) and AHI (2.6+\\/-2.7 versus 3.0+\\/-2.9; P=0.509). Quality of life and ESS improved with CPAP, but there was no difference in the extent of improvement between both devices. Usage of nasal pillows resulted in less reported pressure on the face and more subjects found the nasal pillow the more comfortable device. However, there was no clear overall preference for either device at the end of the study (mask=57%, pillow=43%; P=0.513). The applied CPAP pressure did not correlate with compliance, AHI and ESS. Furthermore, no differences in outcome parameters were noted comparing groups with CPAP pressure <10 and >\\/=10cm H(2) O. Nasal pillows are equally effective in CPAP therapy, but do not generally lead to improved compliance.

  13. Effect of continuous positive airway pressure treatment on serum adiponectin level and mean arterial pressure in male patients with obstructive sleep apnea syndrome

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xi-long; YIN Kai-sheng; LI Chong; JIA En-zhi; LI Yan-qun; GAO Zhao-fang

    2007-01-01

    Background Recent research suggested that obstructive sleep apnea syndrome (OSAS) might be independently associated with hypoadiponectinemia, which was linked to some complications of OSAS, such as hypertension, diabetes,etc. This study was conducted to investigate the effect of continuous positive airway pressure (CPAP) treatment on changes of both serum adiponectin levels and mean arterial pressure and their possible links in male OSAS patients.Methods Twenty-three adult male patients with moderate-to-severe OSAS but without obesity, coronary heart disease and diabetes were recruited. Their blood sampleswere collected and moming mean arterial pressure (MAP) was measured before CPAP treatment and on day 3, 7, 14 of CPAP treatment respectively. The serum adiponectin concentration was tested with radioimmunoassay.Results Compared with the serum adiponectin level before CPAP treatment, no significant change was found in OSAS patients on day 3 and day 7 of CPAP treatment (P>0.05). It was not until day 14 of CPAP treatment did a significant elevation in serum adiponectin level occur (P<0.01). Meanwhile, the MAP showed no statistically significant difference among its levels before CPAP, on day 3 and day 7 of CPAP treatment (P>0.05). However, on day 14 of CPAP treatment,a significantly lower MAP than that obtained before treatment was observed (P<0.05).Conclusions CPAP treatment can gradually reverse hypoadiponectinemia and reduce MAP in OSAS patients.Hypoadiponectinemia might be involved in the pathogenesis of OSAS-mediated hypertension.

  14. Atmospheric pressure does not influence acute diverticular disease

    OpenAIRE

    Velayos, Benito; Pons-Renedo, Fernando; Feranández-Salazar, Luis; Muñoz, María Fe; Olmo, Lourdes del; Almaraz Gómez, Ana; Beltrán de Heredia, Juan; Hernández-González, José Manuel

    2013-01-01

    Producción Científica The article offers information on a study which examines the influence of atmospheric pressure on the development of acute diverticular disease. The value of atmospheric pressure and its daily trends in 2012 was collected to prove whether atmospheric pressure influence this disease by raising intra-diverticular pressure in days with higher atmospheric pressure. The study involved patients with acute diverticulitis who underwent computed tomography.

  15. 持续正压通气对顽固性高血压合并阻塞性睡眠呼吸暂停患者血浆醛固酮水平的影响%Influence of Continuous Positive Airway Pressure on Plasma Aldosterone Concentration in Patients With Resistant Hypertension Combined With Obstructive Sleep Apnea

    Institute of Scientific and Technical Information of China (English)

    任冬冬; 杨敏华; 李艳艳; 崔应麟

    2016-01-01

    中,单独药物治疗与 CPAP 和药物治疗患者治疗前夜间 SBP、24 h SBP、AHI,治疗后日间 SBP、日间 DBP、夜间 SBP、夜间 DBP、24 h DBP、AHI、PAC 水平比较,差异均有统计学意义(P ﹤0.05);单独药物治疗患者治疗后 AHI 与治疗前比较,差异有统计学意义(P ﹤0.05);CPAP 和药物治疗患者治疗后日间 SBP、日间 DBP、夜间 SBP、夜间 DBP、24 h DBP、AHI、Epworth 嗜睡评分及 PAC 水平与治疗前比较,差异有统计学意义(P ﹤0.05)。以治疗前 PAC 为因变量,年龄、BMI、血氧饱和度﹤90%时间占总睡眠时间的百分比(CT90%)、治疗前24 h SBP、治疗前24 h DBP、治疗前 AHI 为自变量,进行多元线性回归分析,结果显示,回归方程为 y =0.198× CT90%+0.058(P =0.023,R2=0.026)。以治疗后 PAC 为因变量,年龄、BMI、CT90%、治疗前24 h SBP、治疗前24 h DBP、治疗前 AHI 为自变量,进行多元线性回归分析,结果显示,回归方程为 y =0.168×24 h DBP +0.113(P=0.015,R2=0.094)。结论 PAC 可能参与了 OSA 和顽固性高血压的发生过程,CPAP 能有效改善顽固性高血压合并OSA 患者的 PAC 水平。%Objective To investigate the influence of continuous positive airway pressure( CPAP)on the plasma aldosterone concentration(PAC)in patients with resistant hypertension and obstructive sleep apnea(OSA). Methods From July 2012 to October 2013,we enrolled 513 patients with resistant hypertension and OSA who were admitted into Henan Province Hospital of TCM and accorded with inclusion criteria. 17 patients who didn’t received 24 h ABPM and 16 patients with AHI less than 15 times per hour were excluded,and other 480 patients were divided into CPAP group(n = 240)and control group(n= 240)by random number table method. CPAP group and control group respectively received CPAP plus medication and medication alone for 3 months. We recorded patients’ general data,24 h ABPM indexes

  16. Development and evaluation of a self-efficacy instrument for Japanese sleep apnea patients receiving continuous positive airway pressure treatment

    Directory of Open Access Journals (Sweden)

    Saito A

    2015-01-01

    Full Text Available Ayako Saito,1 Shigeko Kojima,2 Fumihiko Sasaki,3 Masamichi Hayashi,4 Yuki Mieno,4 Hiroki Sakakibara,5 Shuji Hashimoto1 1Department of Hygiene, School of Medicine, Fujita Health University, Toyoake, Japan; 2Department of Rehabilitation, Faculty of Health Sciences, Nihon Fukushi University, Handa, Japan; 3SDB Research Laboratory, Takaoka Clinic, Nagoya, Japan; 4Department of Internal Medicine, Division of Respiratory Medicine and Clinical Allergy, Fujita Health University, Toyoake, Japan; 5Tokushige Kokyuki Clinic, Nagoya, Japan Abstract: The purpose of this study was to develop and evaluate a self-efficacy instrument for Japanese obstructive sleep apnea (OSA patients treated with continuous positive airway pressure (CPAP. Analyzed subjects were 653 Japanese OSA patients (619 males and 34 females treated with CPAP at a sleep laboratory in a respiratory clinic in a Japanese city. Based on Bandura's social cognitive theory, the CPAP Self-Efficacy Questionnaire for Sleep Apnea in Japanese (CSESA-J was developed by a focus group of experts, using a group interview of OSA patients for the items of two previous self-efficacy scales for Western sleep apnea patients receiving CPAP treatment. CSESA-J has two subscales, one for self-efficacy and the other for outcome expectancy, and consists of a total of 15 items. Content validity was confirmed by the focus group. Confirmatory factor analysis showed that the factor loadings of self-efficacy and outcome expectancy were 0.47–0.76 and 0.41–0.92, respectively, for the corresponding items. CSESA-J had a significant but weak positive association with the General Self-Efficacy Scale, and a strong positive association with “Self-efficacy scale on health behavior in patients with chronic disease.” Cronbach’s alpha coefficient was 0.85 for the self-efficacy subscale and 0.89 for the outcome expectancy subscale. The intraclass correlation coefficient using data from the first and second measurements with

  17. Hereditary and microbiological factors influencing the airway immunological profile of neonates

    DEFF Research Database (Denmark)

    Følsgaard, Nilofar

    2012-01-01

    Asthma and wheezing together with the other atopic disorders; allergy, eczema and rhinitis are the most common chronic diseases in children with major impact on quality of life for patients and significant socioeconomic costs due to health care utilization. The airway mucosa is constantly exposed...... the penetration and impact of the exposome. The ability to mediate a balanced and appropriate immune response is fundamental for managing healthy airways while inappropriate release of inflammatory mediators may have unfavorable long-term consequences such as asthma. Genetic predisposition to atopic diseases...... is well-recognized, with estimated heritability as high as 60% in asthma. Atopic hereditary disease linkage in the offspring seems stronger for maternal than paternal atopic disease. But it is not known how parental atopic disease may affect early immunity in the target organ, the airways. COPSAC has...

  18. Cystic fibrosis airway secretions exhibit mucin hyperconcentration and increased osmotic pressure

    Science.gov (United States)

    Henderson, Ashley G.; Ehre, Camille; Button, Brian; Abdullah, Lubna H.; Cai, Li-Heng; Leigh, Margaret W.; DeMaria, Genevieve C.; Matsui, Hiro; Donaldson, Scott H.; Davis, C. William; Sheehan, John K.; Boucher, Richard C.; Kesimer, Mehmet

    2014-01-01

    The pathogenesis of mucoinfective lung disease in cystic fibrosis (CF) patients likely involves poor mucus clearance. A recent model of mucus clearance predicts that mucus flow depends on the relative mucin concentration of the mucus layer compared with that of the periciliary layer; however, mucin concentrations have been difficult to measure in CF secretions. Here, we have shown that the concentration of mucin in CF sputum is low when measured by immunologically based techniques, and mass spectrometric analyses of CF mucins revealed mucin cleavage at antibody recognition sites. Using physical size exclusion chromatography/differential refractometry (SEC/dRI) techniques, we determined that mucin concentrations in CF secretions were higher than those in normal secretions. Measurements of partial osmotic pressures revealed that the partial osmotic pressure of CF sputum and the retained mucus in excised CF lungs were substantially greater than the partial osmotic pressure of normal secretions. Our data reveal that mucin concentration cannot be accurately measured immunologically in proteolytically active CF secretions; mucins are hyperconcentrated in CF secretions; and CF secretion osmotic pressures predict mucus layer–dependent osmotic compression of the periciliary liquid layer in CF lungs. Consequently, mucin hypersecretion likely produces mucus stasis, which contributes to key infectious and inflammatory components of CF lung disease. PMID:24892808

  19. Effects of continuous positive airway pressure treatment on clinic and ambulatory blood pressures in patients with obstructive sleep apnea and resistant hypertension: a randomized controlled trial.

    Science.gov (United States)

    Muxfeldt, Elizabeth S; Margallo, Victor; Costa, Leonardo M S; Guimarães, Gleison; Cavalcante, Aline H; Azevedo, João C M; de Souza, Fabio; Cardoso, Claudia R L; Salles, Gil F

    2015-04-01

    The effect of continuous positive airway pressure (CPAP) on blood pressures (BPs) in patients with resistant hypertension and obstructive sleep apnea is not established. We aimed to evaluate it in a randomized controlled clinical trial, with blinded assessment of outcomes. Four hundred thirty-four resistant hypertensive patients were screened and 117 patients with moderate/severe obstructive sleep apnea, defined by an apnea-hypopnea index ≥15 per hour, were randomized to 6-month CPAP treatment (57 patients) or no therapy (60 patients), while maintaining antihypertensive treatment. Clinic and 24-hour ambulatory BPs were obtained before and after 6-month treatment. Primary outcomes were changes in clinic and ambulatory BPs and in nocturnal BP fall patterns. Intention-to-treat and per-protocol (limited to those with uncontrolled ambulatory BPs) analyses were performed. Patients had mean (SD) 24-hour BP of 129(16)/75(12) mm Hg, and 59% had uncontrolled ambulatory BPs. Mean apnea-hypopnea index was 41 per hour and 58.5% had severe obstructive sleep apnea. On intention-to-treat analysis, there was no significant difference in any BP change, neither in nocturnal BP fall, between CPAP and control groups. The best effect of CPAP was on night-time systolic blood pressure in per-protocol analysis, with greater reduction of 4.7 mm Hg (95% confidence interval, -11.3 to +3.1 mm Hg; P=0.24) and an increase in nocturnal BP fall of 2.2% (95% confidence interval, -1.6% to +5.8%; P=0.25), in comparison with control group. In conclusion, CPAP treatment had no significant effect on clinic and ambulatory BPs in patients with resistant hypertension and moderate/severe obstructive sleep apnea, although a beneficial effect on night-time systolic blood pressure and on nocturnal BP fall might exist in patients with uncontrolled ambulatory BP levels.

  20. Obesity and obstructive sleep apnoea: mechanisms for increased collapsibility of the passive pharyngeal airway.

    Science.gov (United States)

    Isono, Shiroh

    2012-01-01

    Epidemiological evidence suggests there are significant links between obesity and obstructive sleep apnoea (OSA), with a particular emphasis on the importance of fat distribution in the development of OSA. In patients with OSA, the structure of the pharyngeal airway collapses. A collapsible tube within a rigid box collapses either due to decreased intraluminal pressure or increased external tissue pressure (i.e. reduction in transmural pressure), or due to reduction in the longitudinal tension of the tube. Accordingly, obesity should structurally increase the collapsibility of the pharyngeal airway due to excessive fat deposition at two distinct locations. In the pharyngeal airway region, excessive soft tissue for a given maxillomandibular enclosure size (upper airway anatomical imbalance) can increase tissue pressure surrounding the pharyngeal airway, thereby narrowing the airway. Even mild obesity may cause anatomical imbalance in individuals with a small maxilla and mandible. Lung volume reduction due to excessive central fat deposition may decrease longitudinal tracheal traction forces and pharyngeal wall tension, changing the 'tube law' in the pharyngeal airway (lung volume dependence of the upper airway). The lung volume dependence of pharyngeal airway patency appears to contribute more significantly to the development of OSA in morbidly obese, apnoeic patients. Neurostructural interactions required for stable breathing may be influenced by obesity-related hormones and cytokines. Accumulating evidence strongly supports these speculations, but further intensive research is needed.

  1. Sleep apnoea and the hypothalamic-pituitary-adrenal axis in men and women: effects of continuous positive airway pressure.

    Science.gov (United States)

    Kritikou, Ilia; Basta, Maria; Vgontzas, Alexandros N; Pejovic, Slobodanka; Fernandez-Mendoza, Julio; Liao, Duanping; Bixler, Edward O; Gaines, Jordan; Chrousos, George P

    2016-02-01

    Previous findings on the association of obstructive sleep apnoea (OSA) and the hypothalamic-pituitary-adrenal (HPA) axis are inconsistent, partly due to the confounding effect of obesity and infrequent sampling. Our goal was to examine whether in a relatively nonobese population, OSA is associated with elevated cortisol levels and to assess the effects of a 2-month placebo-controlled continuous positive airway pressure (sham-CPAP) use.72 subjects (35 middle-aged males and post-menopausal females with OSA, and 37 male and female controls) were studied in the sleep laboratory for four nights. 24-h blood sampling was performed every hour on the fourth day and night in the sleep laboratory at baseline, after sham-CPAP and after CPAP treatment.In both apnoeic men and women, OSA was associated with significantly higher 24-h cortisol levels compared with controls, whereas CPAP lowered cortisol levels significantly, close to those of controls.These results suggest that OSA in nonobese men and slightly obese women is associated with HPA axis activation, similar albeit stronger compared with obese individuals with sleep apnoea. Short-term CPAP use decreased cortisol levels significantly compared with baseline, indicating that CPAP may have a protective effect against comorbidities frequently associated with chronic activation of the HPA axis, e.g. hypertension.

  2. Effects of 12 months continuous positive airway pressure on sympathetic activity related brainstem function and structure in obstructive sleep apnea.

    Directory of Open Access Journals (Sweden)

    Luke Anthony Henderson

    2016-03-01

    Full Text Available Muscle sympathetic nerve activity (MSNA is greatly elevated in patients with obstructive sleep apnoea (OSA during normoxic daytime wakefulness. Increased MSNA is a precursor to hypertension and elevated cardiovascular morbidity and mortality. However, the mechanisms underlying the high MSNA in OSA are not well understood. In this study we used concurrent microneurography and magnetic resonance imaging to explore MSNA-related brainstem activity changes and anatomical changes in 15 control and 15 subjects with OSA prior to and following 6 and 12 months of continuous positive airway pressure (CPAP treatment. We found that 6 and 12 months of CPAP treatment significantly reduced the elevated resting MSNA in individuals with OSA. Furthermore, this MSNA reduction was associated with restoration of MSNA-related activity and structural changes in the medullary raphe, rostral ventrolateral medulla, dorsolateral pons and ventral midbrain. This restoration occurred after 6 months of CPAP treatment and was maintained following 12 months CPAP. These findings show that continual CPAP treatment is an effective long-term treatment for elevated MNSA likely due to its effects on restoring brainstem structure and function.

  3. Effect of Continuous Positive Airway Pressure on Adiponectin in Patients with Obstructive Sleep Apnea: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Li-Da Chen

    Full Text Available Obstructive sleep apnea (OSA has been suggested to be associated with low levels of adiponectin. Continuous positive airway pressure (CPAP is the gold standard treatment for OSA; however, previous studies assessing the effect of CPAP on adiponectin in patients with OSA yielded conflicting results. The present meta-analysis was performed to determine whether CPAP therapy could increase adiponectin levels.Two reviewers independently searched PubMed, Cochrane library, Embase and Web of Science before February 2015. Information on characteristics of subjects, study design and pre- and post-CPAP treatment of serum adiponectin was extracted for analysis. Standardized mean difference (SMD was used to analyze the summary estimates for CPAP therapy.Eleven studies involving 240 patients were included in this meta-analysis, including ten observational studies and one randomized controlled study. The meta-analysis showed that there was no change of adiponectin levels before and after CPAP treatment in OSA patients (SMD = 0.059, 95% confidence interval (CI = -0.250 to 0.368, z = 0.37, p = 0.710. Subgroup analyses indicated that the results were not affected by age, baseline body mass index, severity of OSA, CPAP therapy duration, sample size and racial differences.This meta-analysis suggested that CPAP therapy has no impact on adiponectin in OSA patients, without significant changes in body weight. Further large-scale, well-designed long-term interventional investigations are needed to clarify this issue.

  4. Heart rate variability in non-apneic snorers and controls before and after continuous positive airway pressure

    Directory of Open Access Journals (Sweden)

    Mateika Jason H

    2005-07-01

    Full Text Available Abstract Background We hypothesized that sympathetic nervous system activity (SNSA is increased and parasympathetic nervous system activity (PNSA is decreased during non-rapid eye movement (NREM sleep in non-apneic, otherwise healthy, snoring individuals compared to control. Moreover, we hypothesized that these alterations in snoring individuals would be more evident during non-snoring than snoring when compared to control. Methods To test these hypotheses, heart rate variability was used to measure PNSA and SNSA in 11 normotensive non-apneic snorers and 12 control subjects before and 7-days after adapting to nasal continuous positive airway pressure (nCPAP. Results Our results showed that SNSA was increased and PNSA was decreased in non-apneic snorers during NREM compared to control. However, these changes were only evident during the study in which snoring was eliminated with nCPAP. Conversely, during periods of snoring SNSA and PNSA were similar to measures obtained from the control group. Additionally, within the control group, SNSA and PNSA did not vary before and after nCPAP application. Conclusion Our findings suggest that long-lasting alterations in autonomic function may exist in snoring subjects that are otherwise healthy. Moreover, we speculate that because of competing inputs (i.e. inhibitory versus excitatory inputs to the autonomic nervous system during snoring, the full impact of snoring on autonomic function is most evident during non-snoring periods.

  5. Extreme REM Rebound during Continuous Positive Airway Pressure Titration for Obstructive Sleep Apnea in a Depressed Patient

    Directory of Open Access Journals (Sweden)

    Anna Lo Bue

    2014-01-01

    Full Text Available A 20% increase in REM sleep duration has been proposed as a threshold to identify REM rebound in patients with obstructive sleep apnea (OSA who start continuous positive airway pressure (CPAP treatment. We describe the case of one patient with OSA who showed an unexpectedly high degree of REM rebound during titration of CPAP. A 34-year-old man was diagnosed with OSA. He remained untreated for many years, during which he developed systemic hypertension, depression, and severe daytime somnolence. When he was reevaluated sixteen years later, his Epworth sleepiness score was 18, and his OSA had greatly worsened (apnea/hypopnea index: 47, lowest nocturnal saturation: 57%. He underwent a successful CPAP titration during nocturnal polysomnography. Electroencephalographic analysis of the sleep recording revealed a huge amount of REM sleep, accounting for 72% of the total sleep time. When asked, the patient referred that he had suddenly interrupted paroxetine assumption three days before the polysomnography. The very large REM rebound observed in this patient could be due to additional effects of initiation of CPAP therapy and suspension of antidepressive treatment. This case does not report any dangerous consequence, but sudden antidepressive withdrawal could be dangerous for patients with OSA who develop hypoventilation during REM sleep with CPAP application.

  6. Oxidative stress mediated arterial dysfunction in patients with obstructive sleep apnoea and the effect of continuous positive airway pressure treatment

    Directory of Open Access Journals (Sweden)

    Del Ben Maria

    2012-07-01

    Full Text Available Abstract Background Several studies suggest an increase of oxidative stress and a reduction of endothelial function in obstructive sleep apnoea syndrome (OSAS. We assessed the association between OSAS, endothelial dysfunction and oxidative stress. Further aim was to evaluate the effect of nasal continuous positive airway pressure (nCPAP on oxidative stress and arterial dysfunction. Methods We studied 138 consecutive patients with heavy snoring and possible OSAS. Patients underwent unattended overnight home polysomnography. Ten patients with severe OSAS were revaluated after 6 months of nCPAP therapy. To assess oxidative stress in vivo, we measured urinary 8-iso-PGF2α and serum levels of soluble NOX2-derived peptide (sNOX2-dp. Serum levels of nitrite/nitrate (NOx were also determined. Flow-mediated brachial artery dilation (FMD was measured to asses endothelial function. Results Patients with severe OSAS had higher urinary 8-iso-PGF2α (p Conclusions The results of our study indicate that patients with OSAS and cardiometabolic comorbidities have increased oxidative stress and arterial dysfunction that are partially reversed by nCPAP treatment.

  7. Influence of Asian dust particles on immune adjuvant effects and airway inflammation in asthma model mice.

    Directory of Open Access Journals (Sweden)

    Jun Kurai

    Full Text Available An Asian dust storm (ADS contains airborne particles that affect conditions such as asthma, but the mechanism of exacerbation is unclear. The objective of this study was to compare immune adjuvant effects and airway inflammation induced by airborne particles collected on ADS days and the original ADS soil (CJ-1 soil in asthma model mice.Airborne particles were collected on ADS days in western Japan. NC/Nga mice were co-sensitized by intranasal instillation with ADS airborne particles and/or Dermatophagoides farinae (Df, and with CJ-1 soil and/or Df for 5 consecutive days. Df-sensitized mice were stimulated with Df challenge intranasally at 7 days after the last Df sensitization. At 24 hours after challenge, serum allergen specific antibody, differential leukocyte count and inflammatory cytokines in bronchoalveolar lavage fluid (BALF were measured, and airway inflammation was examined histopathologically.Co-sensitization with ADS airborne particles and Df increased the neutrophil and eosinophil counts in BALF. Augmentation of airway inflammation was also observed in peribronchiolar and perivascular lung areas. Df-specific serum IgE was significantly elevated by ADS airborne particles, but not by CJ-1 soil. Levels of interleukin (IL-5, IL-13, IL-6, and macrophage inflammatory protein-2 were higher in BALF in mice treated with ADS airborne particles.These results suggest that substances attached to ADS airborne particles that are not in the original ADS soil may play important roles in immune adjuvant effects and airway inflammation.

  8. All-cause mortality from obstructive sleep apnea in male and female patients with and without continuous positive airway pressure treatment

    DEFF Research Database (Denmark)

    Jennum, Poul; Tønnesen, Philip; Ibsen, Rikke;

    2015-01-01

    BACKGROUND: More information is needed about the effect on mortality of continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA), especially in women. METHODS: We employed a historical cohort study design, using data from 25,389 patients with a diagnosis of OSA......, irrespective of whether they received CPAP treatment. CPAP treatment improved survival, as illustrated by the hazard ratio of 0.62 (P

  9. Airway management and morbid obesity

    DEFF Research Database (Denmark)

    Kristensen, Michael S

    2010-01-01

    airway and the function of the lungs (decreased residual capacity and aggravated ventilation perfusion mismatch) worse than in lean patients. Proper planning and preparation of airway management is essential, including elevation of the patient's upper body, head and neck. Preoxygenation is mandatory...... solely on whether morbid obesity is present or not. It is important to ensure sufficient depth of anaesthesia before initiating manipulation of the airway because inadequate anaesthesia depth predisposes to aspiration if airway management becomes difficult. The intubating laryngeal mask airway is more...... pressure, noninvasive ventilation and physiotherapy....

  10. Influence of chemical and physical forms of ambient air acids on airway doses

    Energy Technology Data Exchange (ETDEWEB)

    Larson, T.V.

    1989-02-01

    The effects of ambient relative humidity and particle size on acid deposition within the airways have been examined with a computer model. For H/sub 2/SO/sub 4/ particles initially at 90% relative humidity in ambient air that are inhaled via the nose or mouth, there is significant deposition of acid in the airways even in the presence of typical values of respiratory NH/sub 3/. When these same particles are found in a fog at 100.015% relative humidity, there is significant deposition of acid in the nasal region during nose breathing but insignificant deposition to the deep lung for either nose or mouth breathing. The factors governing the partitioning of labile acid gases in the gas and liquid phases prior to inhalation are also discussed.

  11. Effects of continuous positive airway pressure on blood pressure in patients with resistant hypertension and obstructive sleep apnea: a meta-analysis

    Science.gov (United States)

    Iftikhar, Imran H.; Valentine, Christopher W.; Bittencourt, Lia R.A.; Cohen, Debbie L.; Fedson, Annette C.; Gíslason, Thorarinn; Penzel, Thomas; Phillips, Craig L.; Yu-sheng, Lin; Pack, Allan I.; Magalang, Ulysses J.

    2015-01-01

    Objective To systematically analyze the studies that have examined the effect of continuous positive airway pressure (CPAP) on blood pressure (BP) in patients with resistant hypertension and obstructive sleep apnea (OSA). Methods Design – meta-analysis of observational studies and randomized controlled trials (RCTs) indexed in PubMed and Ovid (All Journals@Ovid). participants: individuals with resistant hypertension and OSA; interventions – CPAP treatment. Results A total of six studies met the inclusion criteria for preintervention to postintervention analyses. The pooled estimates of mean changes after CPAP treatment for the ambulatory (24-h) SBP and DBP from six studies were −7.21 mmHg [95% confidence interval (CI): −9.04 to −5.38; P <0.001; I2 58%) and −4.99 mmHg (95% CI: −6.01 to −3.96; P <0.001; I2 31%), respectively. The pooled estimate of the ambulatory SBP and DBP from the four RCTs showed a mean net change of −6.74 mmHg [95% CI: −9.98 to −3.49; P <0.001; I2 61%] and −5.94 mmHg (95% CI: −9.40 to −2.47; P =0.001; I2 76%), respectively, in favor of the CPAP group. Conclusion The pooled estimate shows a favorable reduction of BP with CPAP treatment in patients with resistant hypertension and OSA. The effects sizes are larger than those previously reported in patients with OSA without resistant hypertension. PMID:25243523

  12. Randomized controlled trial comparing nasal intermittent positive pressure ventilation and nasal continuous positive airway pressure in premature infants after tracheal extubation

    Directory of Open Access Journals (Sweden)

    Daniela Franco Rizzo Komatsu

    Full Text Available Summary Objective: To analyze the frequency of extubation failure in premature infants using conventional mechanical ventilation (MV after extubation in groups subjected to nasal intermittent positive pressure ventilation (nIPPV and continuous positive airway pressure (nCPAP. Method: Seventy-two premature infants with respiratory failure were studied, with a gestational age (GA ≤ 36 weeks and birth weight (BW > 750 g, who required tracheal intubation and mechanical ventilation. The study was controlled and randomized in order to ensure that the members of the groups used in the research were chosen at random. Randomization was performed at the time of extubation using sealed envelopes. Extubation failure was defined as the need for re-intubation and mechanical ventilation during the first 72 hours after extubation. Results: Among the 36 premature infants randomized to nIPPV, six (16.6% presented extubation failure in comparison to 11 (30.5% of the 36 premature infants randomized to nCPAP. There was no statistical difference between the two study groups regarding BW, GA, classification of the premature infant, and MV time. The main cause of extubation failure was the occurrence of apnea. Gastrointestinal and neurological complications did not occur in the premature infants participating in the study. Conclusion: We found that, despite the extubation failure of the group of premature infants submitted to nIPPV being numerically smaller than in premature infants submitted to nCPAP, there was no statistically significant difference between the two modes of ventilatory support after extubation.

  13. Effectiveness of continuous positive airway pressure in lowering blood pressure in patients with obstructive sleep apnea: a critical review of the literature

    Directory of Open Access Journals (Sweden)

    Fatureto-Borges F

    2016-03-01

    Full Text Available Fernanda Fatureto-Borges,1 Geraldo Lorenzi-Filho,2 Luciano F Drager1,3 1Hypertension Unit, Heart Institute (InCor, 2Sleep Laboratory, Pulmonary Division, 3Hypertension Unit, Renal Division, University of Sao Paulo Medical School, Sao Paulo, Brazil Abstract: Obstructive sleep apnea (OSA is an extremely common comorbid condition in patients with hypertension, with a prevalence of ~50%. There is growing evidence suggesting that OSA is a secondary cause of hypertension, associated with both poor blood pressure (BP control and target organ damage in patients with hypertension. The application of continuous positive airway pressure (CPAP during sleep is the gold standard treatment of moderate- to-severe OSA and very effective in abolishing obstructive respiratory events. However, several meta-analyses showed that the overall impact of CPAP on BP is modest (~2 mmHg. There are several potential reasons for this disappointing finding, including the heterogeneity of patients studied (normotensive patients, controlled, and uncontrolled patients with hypertension, nonideal CPAP compliance, clinical presentation (there is some evidence that the positive impact of CPAP on lowering BP is more evident in sleepy patients, and the multifactorial nature of hypertension. In this review, we performed a critical analysis of the literature evaluating the impact of CPAP on BP in several subgroups of patients. We finally discussed perspectives in this important research area, including the urgent need to identify predictors of BP response to CPAP and the importance of precision medicine in this scenario. Keywords: cardiovascular disease, CPAP, hypertension, sleep apnea, treatment

  14. Sleep-related breathing disorders. 5. Nasal continuous positive airway pressure treatment for obstructive sleep apnoea.

    Science.gov (United States)

    Grunstein, R R

    1995-10-01

    CPAP should be considered the first line of treatment in patients with moderate to severe obstructive sleep apnoea. In our centre in Sydney this generally means patients with more than 20 apnoea/hypopnoeas per hour with repeated dips in oxyhaemoglobin saturation and usually some symptomatology. Despite this first line role of nasal CPAP, recent objective studies question whether earlier enthusiastic reports on adherence to CPAP are correct. The role of technical innovations in new CPAP machines in improving usage remains to be tested. The "drop out" rate from physician selection for a CPAP trial to highly compliant user is certainly more than 50% of patients. What happens to these patients? Data from some studies suggest that surgical treatments are used, at least in the USA, but in all probability many of these patients remain untreated. The challenge in the next decade is either to improve CPAP devices to increase usage in this group or to develop other treatment options. The role of intensive inhospital "acclimatisation" to CPAP also has yet to be objectively tested. It is unclear whether "intelligent" CPAP will make huge inroads in increasing the number of patients who accept CPAP trials, prescriptions, or compliance. It will have minimal impact on patients with mask problems or claustrophobia or those who feel that CPAP is inconvenient. There is a high likelihood that it will reduce technologist workload during CPAP titration studies. "Intelligent" CPAP may help to reduce total overnight mouth leakage and therefore reduce nasal side effects. The current expense of developing such devices will mean that they are unlikely to supersede much cheaper standard "one pressure" CPAP machines in the next few years.

  15. Obstructive sleep apnea in Type 2 diabetes and impact of continuous positive airway pressure therapy on glycemic control

    Directory of Open Access Journals (Sweden)

    Javid Ahmad Malik

    2017-01-01

    Full Text Available Background: Obstructive sleep apnea (OSA and type 2 diabetes mellitus (T2DM are two interacting epidemics both with high prevalence and morbidity. Both epidemiologic and clinical studies suggest that the majority of patients with T2DM also have OSA and untreated OSA in these patients results in poor glycemic control leading to acceleration of diabetes-related complications. Objectives: To assess the prevalence and severity of OSA in T2DM patients and to assess the impact of OSA treatment on presenting symptoms and hemoglobin A1c (HbA1c. Methods: We performed polysomnography (PSG studies and measured HbA1c in 62 consecutive patients with T2DM that were referred from various subspecialty clinics from July 2011 to August 2013. Results: In our 62 diabetic patients, 59 (95.2% had abnormal PSG. Based on Apnea–Hypopnea Index (AHI score, 3 (5.1% patients had mild, 28 (47.5% had moderate, and 28 (47.5% had severe OSA. The mean AHI of diabetic patients was significantly more than nondiabetic patients, i.e., 25.7 versus 19.7 (P = 0.001. Variables that significantly correlated with the presence of OSA include age, gender, body mass index (BMI, hypertension, diabetes, and cardiovascular disease (P < 0.05; however, on logistic regression only BMI, hypertension, and nocturia correlated with OSA. Overall, 59% of diabetic patients showed improvement in their glycemic control as measured by HbA1c with continuous positive airway pressure (CPAP treatment. Significant, moderate, and mild categories of treatment response were respectively observed in 7%, 20%, and 32% of patients. Conclusion: Treatment of OSA with CPAP reduces HbA1c in a significant number of diabetics.

  16. Obstructive sleep apnea in Type 2 diabetes and impact of continuous positive airway pressure therapy on glycemic control

    Science.gov (United States)

    Malik, Javid Ahmad; Masoodi, Shariq Rashid; Shoib, Sheikh

    2017-01-01

    Background: Obstructive sleep apnea (OSA) and type 2 diabetes mellitus (T2DM) are two interacting epidemics both with high prevalence and morbidity. Both epidemiologic and clinical studies suggest that the majority of patients with T2DM also have OSA and untreated OSA in these patients results in poor glycemic control leading to acceleration of diabetes-related complications. Objectives: To assess the prevalence and severity of OSA in T2DM patients and to assess the impact of OSA treatment on presenting symptoms and hemoglobin A1c (HbA1c). Methods: We performed polysomnography (PSG) studies and measured HbA1c in 62 consecutive patients with T2DM that were referred from various subspecialty clinics from July 2011 to August 2013. Results: In our 62 diabetic patients, 59 (95.2%) had abnormal PSG. Based on Apnea–Hypopnea Index (AHI) score, 3 (5.1%) patients had mild, 28 (47.5%) had moderate, and 28 (47.5%) had severe OSA. The mean AHI of diabetic patients was significantly more than nondiabetic patients, i.e., 25.7 versus 19.7 (P = 0.001). Variables that significantly correlated with the presence of OSA include age, gender, body mass index (BMI), hypertension, diabetes, and cardiovascular disease (P < 0.05); however, on logistic regression only BMI, hypertension, and nocturia correlated with OSA. Overall, 59% of diabetic patients showed improvement in their glycemic control as measured by HbA1c with continuous positive airway pressure (CPAP) treatment. Significant, moderate, and mild categories of treatment response were respectively observed in 7%, 20%, and 32% of patients. Conclusion: Treatment of OSA with CPAP reduces HbA1c in a significant number of diabetics. PMID:28217508

  17. Effect of continuous positive airway pressure treatment on elderly Chinese patients with obstructive sleep apnea in the prethrombotic state

    Institute of Scientific and Technical Information of China (English)

    张希龙; 殷凯生; 王虹; 苏梅; 杨玉

    2003-01-01

    Objectives To characterize the prethrombotic state (PTS) in elderly Chinese patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and the effect of nasal continuous positive airway pressure (nCPAP) ventilation on their PTS.Methods Forty-one elderly patients with moderate and severe OSAHS were enrolled into the OSAHS group and underwent nCPAP treatment. Their blood samples were drawn at 6:00 am and 4:00 pm before and during nCPAP treatment, respectively, to test hemocrit, platelet aggregation (PAG), whole blood viscosity (WBV), plasma fibrinogen (fng), prothrombin time (PT) and activated partial thromboplastin time (APTT). All blood factors were also tested in a control group consisting of 32 healthy elderly Chinese with neither OSAHS nor cerebrocardiac vascular disease. Results In the OSAHS group there was a significantly higher hemocrit, WBV, fng, and a significantly shorter PT and APTT at 6:00 am compared to 4:00 pm before nCPAP treatment, while there was no significant difference among all blood test factors between 6:00 am and 4:00 pm on day 30 of the nCPAP treatment. In the OSAHS group, the hemocrit, WBV, PAG and plasma fng were significantly lower and the PT and APTT were significantly longer at 6:00 am on day 30 of the nCPAP treatment compared to 6:00 am before the nCPAP treatment. A significantly lower hemocrit, but a much longer PT and APTT were observed at 4:00 pm on day 30 of the treatment, compared with 4:00 pm before the treatment. No significant difference among the blood test factors was found between 6:00 am and 4:00 pm blood in the control group or between the control and OSAHS groups after 30 days of nCPAP treatment.Conclusion In elderly Chinese OSAHS patients, PTS could be effectively eliminated by nCPAP treatment.

  18. Elective nasal continuous positive airway pressure to support respiration after prolonged ventilation in infants after congenital cardiac surgery

    Science.gov (United States)

    Gandhi, Hemang; Mishra, Amit; Thosani, Rajesh; Acharya, Himanshu; Shah, Ritesh; Surti, Jigar; Sarvaia, Alpesh

    2017-01-01

    Background: We sought to compare the effectiveness of oxygen (O2) treatment administered by an O2 mask and nasal continuous positive airway pressure (NCPAP) in infants after congenital cardiac surgery. Methods: In this retrospective observational study, 54 infants undergoing corrective cardiac surgery were enrolled. According to the anesthesiologist's preference, the patients ventilated for more than 48 h were either put on NCPAP or O2 mask immediately after extubation. From pre-extubation to 24 h after treatment, arterial blood gas and hemodynamic data were measured. Results: After 24 h of NCPAP institution, the patients showed a significant improvement in oxygenation compared to O2 mask group. Respiratory rate (per minute) decreased from 31.67 ± 4.55 to 24.31 ± 3.69 (P < 0.0001), PO2 (mmHg) increased from 112.12 ± 22.83 to 185.74 ± 14.81 (P < 0.0001), and PCO2 (mmHg) decreased from 42.88 ± 5.01 to 37.00 ± 7.22 (P < 0.0076) in patients on NCPAP. In this group, mean pediatric cardiac surgical Intensive Care Unit (PCSICU) stay was 4.72 ± 1.60 days, with only 2 (11.11%) patients requiring re-intubation. Conclusion: NCPAP can be used safely and effectively in infants undergoing congenital cardiac surgery to improve oxygenation/ventilation. It also reduces the work of breathing, PCSICU stay, and may reduce the likelihood of re-intubation. PMID:28163425

  19. Association between obstructive sleep apnea (OSA and depression and the effect of continuous positive airway pressure (CPAP treatment

    Directory of Open Access Journals (Sweden)

    El-Sherbini AM

    2011-12-01

    Full Text Available Amr Makram El-Sherbini1, Adel Salah Bediwy2, Ashraf El-Mitwalli31Department of Psychiatry, Elminia University Hospital, Faculty of Medicine, Elminia, 2Chest Department, Faculty of Medicine, Tanta University, 3Department of Neurology, Mansoura School of Medicine, University of Mansoura, Mansoura, EgyptBackground: Obstructive sleep apnea (OSA is a relatively common disorder which has a negative impact on the psychological well-being of affected individuals.Objective: To assess the association between OSA and depression as well as the effect of treatment with continuous positive airway pressure (CPAP.Methods: A total of 37 newly diagnosed individuals with OSA underwent an overnight polysomnography and were assessed using the Epworth Sleepiness Scale (ESS, the Hamilton Depression Rating Scale (HDRS, and the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. Patients were assessed before and after 2 months of CPAP use.Results: Of the 37 patients included in the study, 21 (56.7% had clinically relevant depression as indicated by a score >10 on the HDRS and eleven patients (29.7% met the diagnostic criteria for a major depressive episode using the Structured Clinical Interview. Scores on the HDRS were correlated with the Apnea Hypoxia Index, ESS scores, and oxygen saturation. Patients showed a significant reduction in depressive symptoms and improvement in ESS scores after CPAP treatment.Conclusion: Patients with OSA should be screened carefully for depressive disorders. CPAP should be tried first before starting other treatment modalities for depression.Keywords: obstructive sleep apnea, depression in OSA, CPAP and depression

  20. Boussignac continuous positive airway pressure for the management of acute cardiogenic pulmonary edema: prospective study with a retrospective control group

    Directory of Open Access Journals (Sweden)

    Aarts Leon PHJ

    2007-12-01

    Full Text Available Abstract Background Continuous positive airway pressure (CPAP treatment for acute cardiogenic pulmonary edema can have important benefits in acute cardiac care. However, coronary care units are usually not equipped and their personnel not adequately trained for applying CPAP with mechanical ventilators. Therefore we investigated in the coronary care unit setting the feasibility and outcome of the simple Boussignac mask-CPAP (BCPAP system that does not need a mechanical ventilator. Methods BCPAP was introduced in a coronary care unit where staff had no CPAP experience. All consecutive patients transported to our hospital with acute cardiogenic pulmonary edema, a respiratory rate > 25 breaths/min and a peripheral arterial oxygen saturation of Results During the 2-year prospective BCPAP study period 108 patients were admitted with acute cardiogenic pulmonary edema. Eighty-four of these patients (78% were treated at the coronary care unit of which 66 (61% were treated with BCPAP. During the control period 66 patients were admitted over a 1-year period of whom 31 (47% needed respiratory support in the intensive care unit. BCPAP treatment was associated with a reduced hospital length of stay and fewer transfers to the intensive care unit for intubation and mechanical ventilation. Overall estimated savings of approximately € 3,800 per patient were achieved with the BCPAP strategy compared to conventional treatment. Conclusion At the coronary care unit, BCPAP was feasible, medically effective, and cost-effective in the treatment of acute cardiogenic pulmonary edema. Endpoints included mortality, coronary care unit and hospital length of stay, need of ventilatory support, and cost (savings.

  1. Withdrawal of Continuous Positive Airway Pressure Therapy after Malar Advancement and Le Fort II Distraction in a Case of Apert Syndrome with Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Nobuto Onda

    2015-01-01

    Full Text Available Apert syndrome is a congenital syndrome characterized by craniosynostosis and craniofacial dysostosis, among other features, and is reported to cause obstructive sleep apnea (OSA because of upper airway narrowing associated with midfacial dysplasia. We recently encountered a case involving a patient with Apert syndrome complicated by OSA who began to receive continuous positive airway pressure (CPAP therapy at the age of 4. OSA resolved after maxillofacial surgery performed at the age of 11, and CPAP was eventually withdrawn. In pediatric patients with maxillofacial dysplasia complicated by OSA, a long-term treatment plan including CPAP in addition to maxillofacial plastic and reconstructive surgery should be considered in view of the effects of OSA on growth.

  2. Effects of different levels of positive airway pressure on breathing pattern and heart rate variability after coronary artery bypass grafting surgery

    Directory of Open Access Journals (Sweden)

    C.B.F. Pantoni

    2011-01-01

    Full Text Available The application of continuous positive airway pressure (CPAP produces important hemodynamic alterations, which can influence breathing pattern (BP and heart rate variability (HRV. The aim of this study was to evaluate the effects of different levels of CPAP on postoperative BP and HRV after coronary artery bypass grafting (CABG surgery and the impact of CABG surgery on these variables. Eighteen patients undergoing CABG were evaluated postoperatively during spontaneous breathing (SB and application of four levels of CPAP applied in random order: sham (3 cmH2O, 5 cmH2O, 8 cmH2O, and 12 cmH2O. HRV was analyzed in time and frequency domains and by nonlinear methods and BP was analyzed in different variables (breathing frequency, inspiratory tidal volume, inspiratory and expiratory time, total breath time, fractional inspiratory time, percent rib cage inspiratory contribution to tidal volume, phase relation during inspiration, phase relation during expiration. There was significant postoperative impairment in HRV and BP after CABG surgery compared to the preoperative period and improvement of DFAα1, DFAα2 and SD2 indexes, and ventilatory variables during postoperative CPAP application, with a greater effect when 8 and 12 cmH2O were applied. A positive correlation (P < 0.05 and r = 0.64; Spearman was found between DFAα1 and inspiratory time to the delta of 12 cmH2O and SB of HRV and respiratory values. Acute application of CPAP was able to alter cardiac autonomic nervous system control and BP of patients undergoing CABG surgery and 8 and 12 cmH2O of CPAP provided the best performance of pulmonary and cardiac autonomic functions.

  3. Analysis of pressure buildup data influenced by wellbore phase redistribution

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, L.G.; Jones, J.R.; Reynolds, A.C.

    1986-10-01

    This work considers the influence of wellbore phase redistribution effects on the analysis of pressure buildup data. First, the authors show that the pressure responses observed when phase redistribution effects exist consist of three distinct types and delineate the conditions under which each type exists. Second, they investigate the reliability of Fair's type curves for analyzing pressure data. Third, for each type of pressure response, they provide rules for determining when the conventional semilog straight line will begin on a semilog plot of pressure data vs. time. They also consider general procedures that are based on Duhamel's principle for analyzing pressure data when sandface flow rates are also available. They discuss the application of these methods to analyze pressure data influenced by wellbore storage effects and investigate the effect that errors in the measured sandface rate have on the analysis.

  4. The importance of administration of early surfactant and nasal continuous positive airway pressure in newborns with respiratory distress syndrome

    Science.gov (United States)

    Ceylan, Abdullah; Gezer, Suat; Demir, Nihat; Tuncer, Oğuz; Peker, Erdal; Kırımi, Ercan

    2014-01-01

    Aim: Mechanical ventilation is an invasive method and causes to important problems in the respiratory tract and lung parenchyma. The objective of our study was to investigate if administration of early surfactant and nasal continuous positive airway pressure (nCPAP) was superior to delayed surfactant administration and mechanical ventilation. Material and Methods: The study was conducted in the Van 100th Year University, Medical Faculty Hospital, Neonatal Intensive Care Unit. One hundred and nine infants with respiratory distrss syndrome (RDS) with a gestational age of 32 weeks and/or below were included in the study. Surfactant was given to 61 infants in the delivery room or intensive care unit and subsequently nCPAP was administered. Surfactant was administered in 48 infants in the control group and mechanical ventilation was inititated subsequently. Informed consent was obtained from the relatives of all patients and ethics committee approval was also obtained (Approval number: 03.02.2011/15). Results: There was no statistically significant difference between the two groups in terms of gestational age, birth weight, gender, height and head circumference measurements (p>0.05). The mean hospitalization time in the patients in the study group was 24.4±17.8 days, whereas the mean time of nCPAP was 28.4 (4–120) hours. In the study group, intracranial hemorrhage was found with a rate of 27.85%, bronchopulmonary dysplasia was found with a rate of 4.91%, pneumothorax was found with a rate of 3.27%, necrotizing enterocolitis was found with a rate of 3.27%, patent ductus arteriosus was found with a rate of 16.39, sepsis was found with a rate of 22.95% and retinopathy of prematurity was found with a rate of 1.63%. No statistically significant difference was found between the study and control groups in terms of the rates of complications. During the follow-up period, 17 (27.86%) patients were lost. The length of stay on mechanical ventilation in the study group was

  5. Erectile Dysfunction and Sexual Hormone Levels in Men With Obstructive Sleep Apnea: Efficacy of Continuous Positive Airway Pressure.

    Science.gov (United States)

    Zhang, Xiao-Bin; Lin, Qi-Chang; Zeng, Hui-Qing; Jiang, Xing-Tang; Chen, Bo; Chen, Xiao

    2016-01-01

    In this study, the prevalence of erectile dysfunction (ED) and serum sexual hormone levels were evaluated in men with obstructive sleep apnea (OSA). In these patients, the efficacy of continuous positive airway pressure (CPAP) was determined. The 207 men (mean age 44.0 ± 11.1 years) enrolled in the study were stratified within four groups based on their apnea-hypopnea index score: simple snoring (n = 32), mild OSA (n = 29), moderate OSA (n = 38), and severe OSA (n = 108). The International Index of Erectile Dysfunction-5 (IIEF-5) score was obtained from each patient, and blood samples for the analysis of sexual hormones (prolactin, luteotropin, follicle-stimulating hormone, estradiol, progestin, and testosterone) were drawn in the morning after polysomnography. The IIEF-5 test and serum sexual hormone measurements were repeated after 3 months of CPAP treatment in 53 men with severe OSA. The prevalence of ED was 60.6 % in OSA patients overall and 72.2 % in those with severe OSA. Compared with the simple snoring group, patients with severe OSA had significantly lower testosterone levels (14.06 ± 5.62 vs. 17.02 ± 4.68, p = .018) and lower IIEF-5 scores (16.33 ± 6.50 vs. 24.09 ± 1.94, p = .001). The differences in the other sexual hormones between groups were not significant. After 3 months of CPAP treatment, there were no significant changes in sexual hormone levels, but the IIEF-5 score had improved significantly (18.21 ± 4.05 vs. 19.21 ± 3.86, p = .001). Severe OSA patients have low testosterone concentration and high ED prevalence. IIEF-5 scores increased significantly after CPAP treatment, but there was no effect on serum testosterone levels.

  6. Effect of continuous positive airway pressure ventilation on nocturnal ST-segment changes in patients with sleep-disordered breathing

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To determine whether sleep-disordered breathing (SDB) may lead to nocturnal myocardial ischemia and whether the severity of this ischemia may be relieved by nasal continuous positive airway pressure (CPAP). Methods Overnight polysomnogram examination and simultaneous 3-channel Holter monitoring were performed on 76 patients with moderate to severe SDB and no history of coronary heart disease. All the cases were treated with CPAP for one night. ST depression was defined as a ST segment decrease of more than 1 mm from baseline and lasting 1 min or more. The total duration (minutes) of ST depression was indexed to the total sleep time (minutes per hour of sleep). Results Twenty-eight patients (37%) showed ST segment depression during their sleep. Before CPAP treatment, the respiratory disturbance index (RDI) and arousal index were significantly higher during periods of ST depression than when ST segments were isoelectric, whereas no significant difference was found in blood oxygen saturation (SaO2). After the CPAP treatment of patients with ST depression, the duration of ST depression was significantly reduced from 36.8±18.9 to 11.4±13.2 min/h (P<0.05). ST depression-related indexes, including RDI, arousal index and the percentage of sleep time spent at SaO2 below 90% (TS90/ TST), were all significantly decreased, with RDI from 63.4±23.8 to 8.1±6.6 /h, arousal index from 51.2±18.9 to 9.6±5.4 /h, and TS90/ TST from 50.6±21.4 to 12.9±14.7% (P<0.05). Conclusion ST-segment depression is rather common in patients with moderate to severe SDB, and CPAP treatment can significantly reduce the duration of ST depression. ST depression in these patients may reflect the myocardial ischemia that really exists and the non-ischemic changes associated with recurrent SDB.

  7. Continuous Positive Airway Pressure for Motion Management in Stereotactic Body Radiation Therapy to the Lung: A Controlled Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, Jeffrey D. [Department of Radiation Oncology, Chaim Sheba Medical Center, Tel Hashomer, Tel Aviv (Israel); Lawrence, Yaacov R. [Department of Radiation Oncology, Chaim Sheba Medical Center, Tel Hashomer, Tel Aviv (Israel); Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Appel, Sarit; Landau, Efrat; Ben-David, Merav A.; Rabin, Tatiana; Benayun, Maoz; Dubinski, Sergey; Weizman, Noam; Alezra, Dror; Gnessin, Hila; Goldstein, Adam M.; Baidun, Khader [Department of Radiation Oncology, Chaim Sheba Medical Center, Tel Hashomer, Tel Aviv (Israel); Segel, Michael J.; Peled, Nir [Department of Pulmonary Medicine, Chaim Sheba Medical Center, Tel Hashomer, Tel Aviv (Israel); Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Symon, Zvi, E-mail: symonz@sheba.health.gov.il [Department of Radiation Oncology, Chaim Sheba Medical Center, Tel Hashomer, Tel Aviv (Israel); Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel)

    2015-10-01

    Objective: To determine the effect of continuous positive airway pressure (CPAP) on tumor motion, lung volume, and dose to critical organs in patients receiving stereotactic body radiation therapy (SBRT) for lung tumors. Methods and Materials: After institutional review board approval in December 2013, patients with primary or secondary lung tumors referred for SBRT underwent 4-dimensional computed tomographic simulation twice: with free breathing and with CPAP. Tumor excursion was calculated by subtracting the vector of the greatest dimension of the gross tumor volume (GTV) from the internal target volume (ITV). Volumetric and dosimetric determinations were compared with the Wilcoxon signed-rank test. CPAP was used during treatment if judged beneficial. Results: CPAP was tolerated well in 10 of the 11 patients enrolled. Ten patients with 18 lesions were evaluated. The use of CPAP decreased tumor excursion by 0.5 ± 0.8 cm, 0.4 ± 0.7 cm, and 0.6 ± 0.8 cm in the superior–inferior, right–left, and anterior–posterior planes, respectively (P≤.02). Relative to free breathing, the mean ITV reduction was 27% (95% confidence interval [CI] 16%-39%, P<.001). CPAP significantly augmented lung volume, with a mean absolute increase of 915 ± 432 cm{sup 3} and a relative increase of 32% (95% CI 21%-42%, P=.003), contributing to a 22% relative reduction (95% CI 13%-32%, P=.001) in mean lung dose. The use of CPAP was also associated with a relative reduction in mean heart dose by 29% (95% CI 23%-36%, P=.001). Conclusion: In this pilot study, CPAP significantly reduced lung tumor motion compared with free breathing. The smaller ITV, the planning target volume (PTV), and the increase in total lung volume associated with CPAP contributed to a reduction in lung and heart dose. CPAP was well tolerated, reproducible, and simple to implement in the treatment room and should be evaluated further as a novel strategy for motion management in radiation therapy.

  8. Process Factors Influence on Cavity Pressure Behavior in Microinjection Moulding

    DEFF Research Database (Denmark)

    Griffiths, C. A.; Dimov, S. S.; Scholz, S.

    2011-01-01

    about the filling behavior of different polymer melts. In this paper, a pressure sensor mounted inside a tool cavity was employed to analyse maximum cavity pressure, pressure increase rate during filling and pressure work. The influence of four mu IM parameters, melt temperature, mould temperature......, injection speed, and packing pressure on these three pressure-related process parameters was investigated. A design of experiment study was conducted by moulding a test part, a microfluidic component, in three different polymer materials, PP, ABS, and PC. The results show a similar process behavior for all...... three polymers, in particular a higher injection speed led to a reduction of the pressure work while a lower mould temperature reduces the pressure rate. [DOI: 10.1115/1.4003953]...

  9. A mechanical design principle for tissue structure and function in the airway tree.

    Science.gov (United States)

    LaPrad, Adam S; Lutchen, Kenneth R; Suki, Béla

    2013-01-01

    With every breath, the dynamically changing mechanical pressures must work in unison with the cells and soft tissue structures of the lung to permit air to efficiently traverse the airway tree and undergo gas exchange in the alveoli. The influence of mechanics on cell and tissue function is becoming apparent, raising the question: how does the airway tree co-exist within its mechanical environment to maintain normal cell function throughout its branching structure of diminishing dimensions? We introduce a new mechanical design principle for the conducting airway tree in which mechanotransduction at the level of cells is driven to orchestrate airway wall structural changes that can best maintain a preferred mechanical microenvironment. To support this principle, we report in vitro radius-transmural pressure relations for a range of airway radii obtained from healthy bovine lungs and model the data using a strain energy function together with a thick-walled cylinder description. From this framework, we estimate circumferential stresses and incremental Young's moduli throughout the airway tree. Our results indicate that the conducting airways consistently operate within a preferred mechanical homeostatic state, termed mechanical homeostasis, that is characterized by a narrow range of circumferential stresses and Young's moduli. This mechanical homeostatic state is maintained for all airways throughout the tree via airway wall dimensional and mechanical relationships. As a consequence, cells within the airway walls throughout the airway tree experience similar oscillatory strains during breathing that are much smaller than previously thought. Finally, we discuss the potential implications of how the maintenance of mechanical homeostasis, while facilitating healthy tissue-level alterations necessary for maturation, may lead to airway wall structural changes capable of chronic asthma.

  10. Auto-titrating versus fixed continuous positive airway pressure for the treatment of obstructive sleep apnea: a systematic review with meta-analyses

    Directory of Open Access Journals (Sweden)

    Ip Stanley

    2012-03-01

    Full Text Available Abstract Background Obstructive sleep apnea is a relatively common disorder that can lead to lost productivity and cardiovascular disease. The form of positive airway treatment that should be offered is unclear. Methods MEDLINE and the Cochrane Central Trials registry were searched for English language randomized controlled trials comparing auto-titrating positive airway pressure (APAP with continuous positive airway pressure (CPAP in adults with obstructive sleep apnea (inception through 9/2010. Six researchers extracted information on study design, potential bias, patient characteristics, interventions and outcomes. Data for each study were extracted by one reviewer and confirmed by another. Random effects model meta-analyses were performed for selected outcomes. Results Twenty-four randomized controlled trials met the inclusion criteria. In individual studies, APAP and fixed CPAP resulted in similar changes from baseline in the apnea-hypopnea index, most other sleep study measures and quality of life. By meta-analysis, APAP improved compliance by 11 minutes per night (95% CI, 3 to 19 minutes and reduced sleepiness as measured by the Epworth Sleepiness Scale by 0.5 points (95% CI, 0.8 to 0.2 point reduction compared with fixed CPAP. Fixed CPAP improved minimum oxygen saturation by 1.3% more than APAP (95% CI, 0.4 to 2.2%. Studies had relatively short follow-up and generally excluded patients with significant comorbidities. No study reported on objective clinical outcomes. Conclusions Statistically significant differences were found but clinical importance is unclear. Because the treatment effects are similar between APAP and CPAP, the therapy of choice may depend on other factors such as patient preference, specific reasons for non-compliance and cost.

  11. Cerebral hemodynamics in patients with obstructive sleep apnea syndrome monitored with near-infrared spectroscopy (NIRS) during positive airways pressure (CPAP) therapy: a pilot study

    Science.gov (United States)

    Zhang, Zhongxing; Schneider, Maja; Laures, Marco; Fritschi, Ursula; Lehner, Isabella; Qi, Ming; Khatami, Ramin

    2014-03-01

    In obstructive sleep apnea syndrome (OSA) the periodic reduction or cessation of breathing due to narrowing or occlusion of the upper airway during sleep leads to daytime symptoms and increased cardiovascular risk, including stroke. The higher risk of stroke is related to the impairment in cerebral vascular autoregulation. Continuous positive airways pressure (CPAP) therapy at night is the most effective treatment for OSA. However, there is no suitable bedside monitoring method evaluating the treatment efficacy of CPAP therapy, especially to monitor the recovery of cerebral hemodynamics. NIRS is ideally suited for non-invasive monitoring the cerebral hemodynamics during sleep. In this study, we will for first time assess dynamic changes of cerebral hemodynamics during nocturnal CPAP therapy in 3 patients with OSA using NIRS. We found periodic oscillations in HbO2, HHb, tissue oxygenation index (TOI) and blood volume associated with periodic apnea events without CPAP in all OSA patients. These oscillations were gradually attenuated and finally eliminated with the stepwise increments of CPAP pressures. The oscillations were totally eliminated in blood volume earlier than in other hemodynamic parameters. These results suggested that 1) the cerebral hemodynamic oscillations induced by OSA events can effectively be attenuated by CPAP therapy, and 2) blood flow and blood volume recovered first during CPAP therapy, followed by the recovery of oxygen consumption. Our study suggested that NIRS is a useful tool to evaluate the efficacy of CPAP therapy in patients with OSA bedside and in real time.

  12. Effects of nasal continuous positive airway pressure treatment on insulin resistance and ghrelin levels in non-diabetic apnoeic patients with coronary heart disease

    Institute of Scientific and Technical Information of China (English)

    YANG Dan; LIU Zhi-hong; ZHAO Qing; LUO Qin

    2013-01-01

    Background Obesity is a common risk factor for several diseases.Obesity related hormone and increased insulin resistance (IR) may contribute to the effects of obstructive sleep apnoea on cardiovascular consequences.We investigated ghrelin and IR in non-diabetic apnoeic patients with stable coronary heart disease and assessed the effects of continuous positive airway pressure (CPAP).Methods Plasma ghrelin,glucose and insulin were measured in 22 patients with CPAP and 22 matched controls without CPAP at baseline and three months.Indexes including homeostasis model assessment IR (HOMA IR),HOMA S and HOMA β were calculated for the assessment of IR,insulin sensitivity and pancreatic β cell function.Results At three months follow-up,plasma ghrelin levels and HOMA IR in CPAP group were significantly decreased (,P=0.002 and 0.046,respectively) while those in control group increased significantly (P=0.012 and 0.009,respectively).Significant moderate correlations were found between ghrelin vs.HOMA IR and ghrelin vs.HOMA S after CPAP,however,for those without CPAP,no significant associations were observed.Conclusions Short-term effective continuous positive airway pressure had a significant effect on lowering plasma ghrelin levels and IR,but not body fat.Further large scale and longer term studies are warranted to corroborate these findings.

  13. Analysis of airways in computed tomography

    DEFF Research Database (Denmark)

    Petersen, Jens

    Chronic Obstructive Pulmonary Disease (COPD) is major cause of death and disability world-wide. It affects lung function through destruction of lung tissue known as emphysema and inflammation of airways, leading to thickened airway walls and narrowed airway lumen. Computed Tomography (CT) imaging...... have become the standard with which to assess emphysema extent but airway abnormalities have so far been more challenging to quantify. Automated methods for analysis are indispensable as the visible airway tree in a CT scan can include several hundreds of individual branches. However, automation...... of scan on airway dimensions in subjects with and without COPD. The results show measured airway dimensions to be affected by differences in the level of inspiration and this dependency is again influenced by COPD. Inspiration level should therefore be accounted for when measuring airways, and airway...

  14. Sustained inflation and incremental mean airway pressure trial during conventional and high-frequency oscillatory ventilation in a large porcine model of acute respiratory distress syndrome

    Directory of Open Access Journals (Sweden)

    Wunder Christian

    2006-06-01

    Full Text Available Abstract Background To compare the effect of a sustained inflation followed by an incremental mean airway pressure trial during conventional and high-frequency oscillatory ventilation on oxygenation and hemodynamics in a large porcine model of early acute respiratory distress syndrome. Methods Severe lung injury (Ali was induced in 18 healthy pigs (55.3 ± 3.9 kg, mean ± SD by repeated saline lung lavage until PaO2 decreased to less than 60 mmHg. After a stabilisation period of 60 minutes, the animals were randomly assigned to two groups: Group 1 (Pressure controlled ventilation; PCV: FIO2 = 1.0, PEEP = 5 cmH2O, VT = 6 ml/kg, respiratory rate = 30/min, I:E = 1:1; group 2 (High-frequency oscillatory ventilation; HFOV: FIO2 = 1.0, Bias flow = 30 l/min, Amplitude = 60 cmH2O, Frequency = 6 Hz, I:E = 1:1. A sustained inflation (SI; 50 cmH2O for 60s followed by an incremental mean airway pressure (mPaw trial (steps of 3 cmH2O every 15 minutes were performed in both groups until PaO2 no longer increased. This was regarded as full lung inflation. The mPaw was decreased by 3 cmH2O and the animals reached the end of the study protocol. Gas exchange and hemodynamic data were collected at each step. Results The SI led to a significant improvement of the PaO2/FiO2-Index (HFOV: 200 ± 100 vs. PCV: 58 ± 15 and TAli: 57 ± 12; p 2-reduction (HFOV: 42 ± 5 vs. PCV: 62 ± 13 and TAli: 55 ± 9; p Ali: 6.1 ± 1 vs. T75: 3.4 ± 0.4; PCV: TAli: 6.7 ± 2.4 vs. T75: 4 ± 0.5; p Conclusion A sustained inflation followed by an incremental mean airway pressure trial in HFOV improved oxygenation at a lower mPaw than during conventional lung protective ventilation. HFOV but not PCV resulted in normocapnia, suggesting that during HFOV there are alternatives to tidal ventilation to achieve CO2-elimination in an "open lung" approach.

  15. Airflow behavior changes in upper airway caused by different head and neck positions: Comparison by computational fluid dynamics.

    Science.gov (United States)

    Wei, Wei; Huang, Shi-Wei; Chen, Lian-Hua; Qi, Yang; Qiu, Yi-Min; Li, Shi-Tong

    2017-02-08

    The feasibility of computational fluid dynamics (CFD) to evaluate airflow characteristics in different head and neck positions has not been established. This study compared the changes in volume and airflow behavior of the upper airway by CFD simulation to predict the influence of anatomical and physiological airway changes due to different head-neck positions on mechanical ventilation. One awake volunteer with no risk of difficult airway underwent computed tomography in neutral position, extension position (both head and neck extended), and sniffing position (head extended and neck flexed). Three-dimensional airway models of the upper airway were reconstructed. The total volume (V) and narrowest area (Amin) of the airway models were measured. CFD simulation with an Spalart-Allmaras model was performed to characterize airflow behavior in neutral, extension, and sniffing positions of closed-mouth and open-mouth ventilation. The comparison result for V was neutral pressure drop and velocity increasing were more obvious in neutral than sniffing or extension position at the same airflow rate. In sniffing position, pressure differences decreased and velocity remained almost constant. Recirculation airflow was generated near the subglottic region in neutral and extension positions. Sniffing position improves airway patency by increasing airway volume and decreasing airway resistance, suggesting that sniffing position may be the optimal choice for mask ventilation.

  16. Influence of inspiratory flow rate, particle size, and airway caliber on aerosolized drug delivery to the lung.

    Science.gov (United States)

    Dolovich, M A

    2000-06-01

    A number of studies in the literature support the use of fine aerosols of drug, inhaled at low IFRs to target peripheral airways, with the objective of improving clinical responses to inhaled therapy (Fig. 8). Attempts have been made to separate response due to changes in total administered dose or the surface concentration of the dose from response due to changes in site of deposition--both are affected by the particle size of the aerosol, with IFR additionally influencing the latter. The tools for measuring dose and distribution have improved over the last 10-15 years, and thus we should expect greater accuracy in these measurements for assessing drug delivery to the lung. There are still issues, though, in producing radiolabeled (99m)technetium aerosols that are precise markers for the pharmaceutical product being tested and in quantitating absolute doses deposited in the lung. PET isotopes may provide the means for directly labelling a drug and perhaps can offer an alternative for making these measurements in the future, but deposition measurements should not be used in isolation; protocols should incorporate clinical tests to provide parallel therapeutic data in response to inhalation of the drug by the various patient populations being studied.

  17. Effects of surgical correction of class III malocclusion on the pharyngeal airway and its influence on sleep apnoea.

    Science.gov (United States)

    Canellas, J V Dos S; Barros, H L M; Medeiros, P J D; Ritto, F G

    2016-12-01

    The objective of this study was to evaluate, through cone beam computed tomography, the immediate changes in pharyngeal airway space (PAS) after orthognathic surgery in class III patients, and to determine the influence of surgery on the development of obstructive sleep apnoea hypopnoea syndrome (OSAHS). A prospective study was conducted; 33 patients were divided into three groups: mandibular setback surgery (nine patients), bimaxillary surgery (18 patients), and maxillary advancement surgery (six patients). PAS measurements obtained pre- and postoperatively were compared using the t-test. All patients were assessed clinically for OSAHS before surgery and at 6 months postoperative using the Berlin questionnaire and a combined clinical assessment, which included the assessment of OSAHS symptoms, Epworth Sleepiness Scale score, and body mass index. Patients undergoing isolated mandibular setback surgery demonstrated a decrease in total PAS volume, in hypopharynx volume, and in minimum cross-sectional area of the pharynx immediately after surgery (P<0.05). The clinical analysis did not reveal signs or symptoms of OSAHS in any of the 33 patients. Although patients who underwent mandibular setback surgery alone demonstrated a volume reduction in the PAS and a decrease in minimum cross-sectional area, these reductions were not accompanied by signs or symptoms of OSAHS.

  18. 肌松程度对食管引流型喉罩与经典喉罩密封性的影响%The Influence of the Depth of Muscle Relaxation on Airway Seal Using ProSeal-Laryngeal Airway and Classic Laryngeal Mask Airway

    Institute of Scientific and Technical Information of China (English)

    陈鹭; 梁敏; 曾凯; 张传汉

    2014-01-01

    目的:观察乳腺癌改良根治术中肌松程度对食管引流型喉罩和经典型喉罩密封的影响。方法择期行乳腺癌改良根治术患者60例,年龄30~60岁,ASAⅠ级或Ⅱ级,体质量指数<30 kg/m2。随机分为食管引流型喉罩组(P组)和经典喉罩组(C组),每组30例。2组均采用纤维支气管镜调整喉罩对位。2组通气罩的压力控制在60 cmH2 O(1 cmH2 O=0.098 kPa)。术中采用全凭静脉麻醉,行间歇正压通气。TOF-Watch SX监测术中肌松状态,记录TOF值分别为0(T1)、20%(T2)、40%(T3)、60%(T4)、80%(T5)时喉罩的口咽部漏气压(OLP)及术中胃胀气、返流误吸等并发症的发生率。结果相同肌松状态下2组间比较:T1~T5各时刻2组的OLP差别无统计学意义(P>0.05)。与T1比较,P组T4和T5的OLP降低,C组T3~ T5时的OLP降低(P<0.05)。2组术中均未发生明显的胃胀气。结论肌松程度对2种喉罩的密封性均有影响,肌松状态越好,2种喉罩的密封性越好。%Objective To evaluate the influence of the depth of muscle relaxation on airway seal u-sing ProSeal-Laryngeal Airway (PLMA) and Classic Laryngeal Mask Airway (CLMA) during radical mas-tectomy . Methods Sixty ASA Ⅰ or Ⅱ patients aged 30~60 years ,body mass index less than 30 kg/m2 undergoing radical mastectomy were enrolled in the study . The patients were randomized to receive either PLMA ventilation (group P) or CLMA ventilation (group C) (n=30 each) ,and we used the fiberoptic bronchoscopy to adjust positions . In group C ,after insertion ,the cuff pressure was set at 60 cmH2 O . Both groups used total intravenous anesthesia and intermittent positive pressure ventilation . T he depth of muscle relaxation determined with TOF-Watch SX monitor . The oropharyngeal leak pressure (OLP) was measured when the TOF ratio was 0(T1 ) ,20% (T2 ) ,40% (T3 ) ,60% (T4 ) and 80% (T5 ) . The inci-dence of

  19. Monitoring Progress and Adherence with Positive Airway Pressure Therapy for Obstructive Sleep Apnea: The Roles of Telemedicine and Mobile Health Applications.

    Science.gov (United States)

    Hwang, Dennis

    2016-06-01

    Technology is changing the way health care is delivered and how patients are approaching their own health. Given the challenge within sleep medicine of optimizing adherence to continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnea (OSA), implementation of telemedicine-based mechanisms is a critical component toward developing a comprehensive and cost-effective solution for OSA management. Key elements include the use of electronic messaging, remote monitoring, automated care mechanisms, and patient self-management platforms. Current practical sleep-related telemedicine platforms include Web-based educational programs, automated CPAP follow-up platforms that promote self-management, and peer-based patient-driven Internet support forums.

  20. Effect of Positive Airway Pressure Therapy on Body Mass Index in Obese Patients With Obstructive Sleep Apnea Syndrome: A Prospective Study.

    Science.gov (United States)

    Rishi, Muhammad Adeel; Copur, Ahmet Sinan; Nadeem, Rashid; Fulambarker, Ashok

    2016-01-01

    Because obesity is a common cause of obstructive sleep apnea syndrome (OSAS), weight loss can be an effective treatment. OSAS also may cause weight gain in some patients. Effective treatment of sleep apnea may facilitate weight loss in obese patients. We hypothesize that positive airway pressure (PAP) therapy is associated with weight loss in obese patients with OSAS. This was a single-center observational prospective cohort study. Forty-five patients were diagnosed with OSAS after polysomnographic analysis in sleep laboratory and underwent continuous positive airway pressure titration. Patients were followed for 3 months in terms of change in body mass index (BMI) and compliance with PAP therapy. Of the 45 patients recruited, 3 patients were eliminated because of miss recruitment. Nine patients had incomplete data, and the rest (n = 33) were included for analysis. The mean age was 54.9 ± 16.9 years (mean ± SD), 93.9% were male, and 90.9% were whites. Mean apnea-hypopnea index was 36.3 ± 28.17 events per hour. Mean BMI before treatment was 34.7 ± 3.9 kg/m. Fifteen patients (45.5%) were compliant with therapy of OSAS with PAP. There was no difference in age, gender, neck circumference, BMI, and apnea-hypopnea index of patients compliant to therapy when compared with those who were not. There was a significant decrease in BMI in patients compliant with PAP therapy compared with noncompliant patients (-1.2 ± 0.7 vs. 0.3 ± 0.9 kg/m, P ≤ 0.001). PAP therapy may cause significant loss of weight within 3 months in obese patients with OSAS. Further study is needed to elucidate the physiological basis of this change.

  1. Influence of geomagnetic activity and atmospheric pressure in hypertensive adults.

    Science.gov (United States)

    Azcárate, T; Mendoza, B

    2017-03-30

    We performed a study of the systolic and diastolic arterial blood pressure behavior under natural variables such as the atmospheric pressure and the horizontal geomagnetic field component. We worked with a group of eight adult hypertensive volunteers, four men and four women, with ages between 18 and 27 years in Mexico City during a geomagnetic storm in 2014. The data was divided by gender, age, and day/night cycle. We studied the time series using three methods: correlations, bivariate analysis, and superposed epoch (within a window of 2 days around the day of occurrence of a geomagnetic storm) analysis, between the systolic and diastolic blood pressure and the natural variables. The correlation analysis indicated a correlation between the systolic and diastolic blood pressure and the atmospheric pressure and the horizontal geomagnetic field component, being the largest during the night. Furthermore, the correlation and bivariate analyses showed that the largest correlations are between the systolic and diastolic blood pressure and the horizontal geomagnetic field component. Finally, the superposed epoch analysis showed that the largest number of significant changes in the blood pressure under the influence of geomagnetic field occurred in the systolic blood pressure for men.

  2. EXPERIMENTAL STUDY ON INFLUENCE OF SUPPLIED PRESSURE FLUCTUATION ON OUTPUT ARACTERISTIC OF PRESSURE CONTROL SYSTEM OF ROLLING MILL

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The infulence of supplied pressure fluctuation on output accuracy for the electro-hydraulic pressure control system of the rolling mill is discussed.Based on the bond graph theory and experimental study,the relationship between the variation of system output pressure and the supplied pressure fluctuation and the influence of the system bandwidth on system output pressure are provided.A theoretical base for determining the allowable fluctuation range of pressure and accurate design of constant pressure source system is obtained.

  3. Temperature field simulation of gob influenced by atmospheric pressure

    Institute of Scientific and Technical Information of China (English)

    王刚; 罗海珠; 梁运涛; 王继仁

    2015-01-01

    The current temperature field model of mine gob does not take the boundary conditions of the atmospheric pressure into account, while the actual atmospheric pressure is influenced by weather, so as to produce differences between ventilation negative pressure of the working face and the negative pressure of gas drainage in gob, thus interfering the calculated results of gob temperature field. According to the characteristics of the actual air flow and temperature change in gob, a two-dimensional temperature field model of the gob was built, and the relational model between the air pressure of intake and outlet of the gob and the atmospheric pressure was established, which was introduced into the boundary conditions of temperature field to conduct calculation. By means of analysis on the simulation example, and comparison with the traditional model, the results indicate that atmospheric pressure change had notable impact on the distribution of gob temperature field. The laboratory test system of gob temperature field was constructed, and the relative error between simulated and measured value was no greater than 9.6%, which verified the effectiveness of the proposed model. This work offers theoretical basis for accurate calculation of temperature and prediction of ignition source in mine gob, and has important implications on preventing spontaneous combustion of coal.

  4. Holding Pressure and Its Influence on Quality in PIM Technology

    Directory of Open Access Journals (Sweden)

    Pavel Petera

    2012-01-01

    Full Text Available The PIM (powder injection molding process consists of several steps in which faults can occur. The quality of the part that is produced usually cannot be seen until the end of the process. It is therefore necessary to find a way to discover the fault earlier in the process. The cause of defects is very often “phase separation” (inhomogeneity in powder distribution, which can also be influenced by the holding pressure. This paper evaluates the powder distribution with a new method based on density measurement. Measurements were made using various holding pressure values.

  5. Curative effect of continuous positive airway pressure on treatment of patients with obstructive sleep apnea hypopnea syndrome and hypertension: A Meta-analysis

    Directory of Open Access Journals (Sweden)

    Bi-fang MIAO

    2016-12-01

    Full Text Available Objective  To systematically evaluate the curative effect of continuous positive airway pressure (CPAP on treatment of patients with obstructive sleep apnea hypopnea syndrome (OSAHS and hypertension. Methods  The data were retrieved of randomized controlled trials (RCTs about the curative effect of CPAP on treatment of patients with OSAHS and hypertension from PubMed, Cochrane Library, CNKI, VIP, CBM and WanFang database from inception to Oct. 2015. Literature screening, data extraction and risk bias assessment were performed by two independent reviewers, and meta-analysis was then carried out by using RevMan 5.3 software. Results  A total of 16 RCTs involving 2101 patients were included. Meta-analysis revealed that, compared with the antihypertensive drug therapy alone, CPAP plus antihypertensive drug therapy significantly reduced the daytime systolic pressure [MD=–12.60, 95%CI(–17.68 to –7.52, P<0.00001], nighttime systolic pressure [MD=–21.90, 95%CI(–25.94 to –17.86, P<0.00001] and nighttime diastolic pressure [MD=–11.90, 95%CI(–15.44 to –8.36, P<0.00001], while created no significant difference in daytime diastolic pressure, 24-h mean systolic pressure and 24-h mean diastolic pressure in a following-up less than 12 weeks. Whereas in the following-up no less than 12 weeks, compared with the antihypertensive drug therapy alone, CPAP plus antihypertensive drug therapy significantly reduced the 24-h mean systolic pressure [MD=–7.88, 95%CI(–12.09 to –3.66, P=0.00002], 24-h mean diastolic pressure [MD=–5.14, 95%CI(–6.00 to –4.28, P<0.00001], daytime systolic pressure [MD=–5.89, 95%CI(–8.79 to –2.98, P<0.0001], daytime diastolic pressure [MD=–4.34, 95%CI(–6.32 to –2.36, P<0.0001]; nighttime systolic pressure [MD=–7.06, 95%CI(–11.12 to –2.99, P=0.0007] and nighttime diastolic pressure [MD=–4.49, 95%CI (–7.39 to –1.58, P=0.006]. Conclusions  The current evidences suggest that on the basis

  6. [A case of respiratory insufficiency after resection of the aortic aneurysm and replacement with a synthetic conduit which recovered by airway pressure release ventilation].

    Science.gov (United States)

    Shimoyama, Yuichiro; Majima, Nozomi; Kadono, Noriko; Ito, Masayuki; Agui, Tomoyuki; Umegaki, Osamu; Minami, Toshiaki

    2011-04-01

    We experienced a patient with respiratory insufficiency after resection of the aortic aneurysm and replacement with a synthetic conduit which recovered by airway pressure release ventilation (APRV) dramatically. A 44-year-old man diagnosed as aortic aneurysm of the descending thoracic aorta was admitted to our hospital and an operation was scheduled. The operation lasted for 19 hours and the time of general anesthesia was 23 hours. The immediate post-operative chest x-ray showed atelectasis of the right upper lobe, elevated right diaphragm and poor aeration of the lungs. A volume-limited mechanical ventilation was used for this patient postoperatively in ICU. But accumulation of carbon dioxide and poor oxygenation were observed. We started APRV by Bennet 840 (Tyco Healthcare, Tokyo). Specifically, we used Bilevel mode (PEEP 20/3 cmH20/3, inspiratory time 3.2 seconds, respiratory rate 15 times per minute, pressure support 20 cm H2O, FI(O2) 1.0). Promptly accumulation of carbon dioxide was improved and atelectasis of the right upper lobe vanished. Additionally, oxygenation was improved. He was weaned from a ventilator on postoperative day 5. We have demonstrated that APRV is an important tool that should be used to improve severe respiratory insufficiency.

  7. Continuous positive airway pressure breathing increases the spread of sensory blockade after low-thoracic epidural injection of lidocaine.

    NARCIS (Netherlands)

    Visser, W.A.; Gielen, M.J.M.; Giele, J.L.P.

    2006-01-01

    Factors affecting the distribution of sensory blockade after epidural injection of local anesthetics remain incompletely clarified. To evaluate if increasing intrathoracic pressure affects the spread of thoracic epidural anesthesia, we randomized 20 patients who received an epidural catheter at the

  8. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

    Science.gov (United States)

    Wain, Louise V; Verwoert, Germaine C; O’Reilly, Paul F; Shi, Gang; Johnson, Toby; Johnson, Andrew D; Bochud, Murielle; Rice, Kenneth M; Henneman, Peter; Smith, Albert V; Ehret, Georg B; Amin, Najaf; Larson, Martin G; Mooser, Vincent; Hadley, David; Dörr, Marcus; Bis, Joshua C; Aspelund, Thor; Esko, Tõnu; Janssens, A Cecile JW; Zhao, Jing Hua; Heath, Simon; Laan, Maris; Fu, Jingyuan; Pistis, Giorgio; Luan, Jian’an; Arora, Pankaj; Lucas, Gavin; Pirastu, Nicola; Pichler, Irene; Jackson, Anne U; Webster, Rebecca J; Zhang, Feng; Peden, John F; Schmidt, Helena; Tanaka, Toshiko; Campbell, Harry; Igl, Wilmar; Milaneschi, Yuri; Hotteng, Jouke-Jan; Vitart, Veronique; Chasman, Daniel I; Trompet, Stella; Bragg-Gresham, Jennifer L; Alizadeh, Behrooz Z; Chambers, John C; Guo, Xiuqing; Lehtimäki, Terho; Kühnel, Brigitte; Lopez, Lorna M; Polašek, Ozren; Boban, Mladen; Nelson, Christopher P; Morrison, Alanna C; Pihur, Vasyl; Ganesh, Santhi K; Hofman, Albert; Kundu, Suman; Mattace-Raso, Francesco US; Rivadeneira, Fernando; Sijbrands, Eric JG; Uitterlinden, Andre G; Hwang, Shih-Jen; Vasan, Ramachandran S; Wang, Thomas J; Bergmann, Sven; Vollenweider, Peter; Waeber, Gérard; Laitinen, Jaana; Pouta, Anneli; Zitting, Paavo; McArdle, Wendy L; Kroemer, Heyo K; Völker, Uwe; Völzke, Henry; Glazer, Nicole L; Taylor, Kent D; Harris, Tamara B; Alavere, Helene; Haller, Toomas; Keis, Aime; Tammesoo, Mari-Liis; Aulchenko, Yurii; Barroso, Inês; Khaw, Kay-Tee; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Eyheramendy, Susana; Org, Elin; Sõber, Siim; Lu, Xiaowen; Nolte, Ilja M; Penninx, Brenda W; Corre, Tanguy; Masciullo, Corrado; Sala, Cinzia; Groop, Leif; Voight, Benjamin F; Melander, Olle; O’Donnell, Christopher J; Salomaa, Veikko; d’Adamo, Adamo Pio; Fabretto, Antonella; Faletra, Flavio; Ulivi, Sheila; Del Greco, M Fabiola; Facheris, Maurizio; Collins, Francis S; Bergman, Richard N; Beilby, John P; Hung, Joseph; Musk, A William; Mangino, Massimo; Shin, So-Youn; Soranzo, Nicole; Watkins, Hugh; Goel, Anuj; Hamsten, Anders; Gider, Pierre; Loitfelder, Marisa; Zeginigg, Marion; Hernandez, Dena; Najjar, Samer S; Navarro, Pau; Wild, Sarah H; Corsi, Anna Maria; Singleton, Andrew; de Geus, Eco JC; Willemsen, Gonneke; Parker, Alex N; Rose, Lynda M; Buckley, Brendan; Stott, David; Orru, Marco; Uda, Manuela; van der Klauw, Melanie M; Zhang, Weihua; Li, Xinzhong; Scott, James; Chen, Yii-Der Ida; Burke, Gregory L; Kähönen, Mika; Viikari, Jorma; Döring, Angela; Meitinger, Thomas; Davies, Gail; Starr, John M; Emilsson, Valur; Plump, Andrew; Lindeman, Jan H; ’t Hoen, Peter AC; König, Inke R; Felix, Janine F; Clarke, Robert; Hopewell, Jemma C; Ongen, Halit; Breteler, Monique; Debette, Stéphanie; DeStefano, Anita L; Fornage, Myriam; Mitchell, Gary F; Smith, Nicholas L; Holm, Hilma; Stefansson, Kari; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Samani, Nilesh J; Preuss, Michael; Rudan, Igor; Hayward, Caroline; Deary, Ian J; Wichmann, H-Erich; Raitakari, Olli T; Palmas, Walter; Kooner, Jaspal S; Stolk, Ronald P; Jukema, J Wouter; Wright, Alan F; Boomsma, Dorret I; Bandinelli, Stefania; Gyllensten, Ulf B; Wilson, James F; Ferrucci, Luigi; Schmidt, Reinhold; Farrall, Martin; Spector, Tim D; Palmer, Lyle J; Tuomilehto, Jaakko; Pfeufer, Arne; Gasparini, Paolo; Siscovick, David; Altshuler, David; Loos, Ruth JF; Toniolo, Daniela; Snieder, Harold; Gieger, Christian; Meneton, Pierre; Wareham, Nicholas J; Oostra, Ben A; Metspalu, Andres; Launer, Lenore; Rettig, Rainer; Strachan, David P; Beckmann, Jacques S; Witteman, Jacqueline CM; Erdmann, Jeanette; van Dijk, Ko Willems; Boerwinkle, Eric; Boehnke, Michael; Ridker, Paul M; Jarvelin, Marjo-Riitta; Chakravarti, Aravinda; Abecasis, Goncalo R; Gudnason, Vilmundur; Newton-Cheh, Christopher; Levy, Daniel; Munroe, Patricia B; Psaty, Bruce M; Caulfield, Mark J; Rao, Dabeeru C

    2012-01-01

    Numerous genetic loci influence systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans 1-3. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N=74,064) and follow-up studies (N=48,607), we identified at genome-wide significance (P= 2.7×10-8 to P=2.3×10-13) four novel PP loci (at 4q12 near CHIC2/PDGFRAI, 7q22.3 near PIK3CG, 8q24.12 in NOV, 11q24.3 near ADAMTS-8), two novel MAP loci (3p21.31 in MAP4, 10q25.3 near ADRB1) and one locus associated with both traits (2q24.3 near FIGN) which has recently been associated with SBP in east Asians. For three of the novel PP signals, the estimated effect for SBP was opposite to that for DBP, in contrast to the majority of common SBP- and DBP-associated variants which show concordant effects on both traits. These findings indicate novel genetic mechanisms underlying blood pressure variation, including pathways that may differentially influence SBP and DBP. PMID:21909110

  9. Study on Influence of Mud Pollution on Formation Fracture Pressure

    Directory of Open Access Journals (Sweden)

    Xiao Hui

    2015-01-01

    Full Text Available The mud pollution may change the mechanical properties of rock during oil and gas drilling process, which affects the prediction of fracture pressure, leads to the failure of hydraulic fracturing treatment. Therefore, it is necessary to study influence of mud pollution on formation fracture pressure to improve the forecasting accuracy. The mud pollution has influences on the modulus of elasticity and the Poisson’s ratio of rock by the mud pollution experiment, the core microstructure is observed around the mud pollution. Based on the experiment and research, the effects of mud pollution on the fracturing pressure are studied by finite element software system ANSYS, the factors such as pollution depth, perforation length and Poisson’s ratio of polluted area are taken into account. The result of the experiment indicated that the modulus of elasticity of rock is reduced and the Poisson’s ratio of rock is increased by the mud pollution. Through computing and analyzing, it can be concluded that increases in pollution depth and Poisson’s ratio can lead to a vast increase in formation fracturing pressure. A calculation example is presented and the results show that the results of this research can provide valuable guidance to the designers of hydraulic fracturing treatment.

  10. A CBCT analysis of influencing factors on the upper airway in children%影响儿童上气道因素的锥体束CT研究

    Institute of Scientific and Technical Information of China (English)

    刘伟涛; 章晶晶; 高雪梅

    2015-01-01

    Objective To explore potential influence factors on the dimensions of the upper airway in children.Methods 50 children aged from 7 to 13 years old (20 males,30 females) were selected.Their maxillary development were between normal to deficienct (SNA 79.85±3.49°),while the development of mandible ranged from normal to overdue (SNB 81.55 ± 3.71°).All children underwent CBCT scan and their 41 dental,occlusal,jaw and facial cephalometric variables were measured with Dolphin Software to evaluate the height,sectional area and corresponding volume in 3 parts of upper airway.Correlated analysis was done both between upper airway variables and general development variables,and upper airway variables and cephalometric variables.Results Age is an important influence factor (r=0.417,P =0.020).Skeletal measurements of Pg-NB,Co-Gn,Ar-Go and Sgo showed statistical significance on the upper airway.So did dental measurements of U1-NA,L1-MP and OB.Conclusions The dimensions of the upper airway were influenced by skeletal and dental structures.The effect of growth on the upper airway were mainly from its role in vertical dimension.%目的 探讨影响儿童上气道大小的影响因素.方法 50例7至13岁儿童,男20例,女30例,上颌发育由正常至不足(SNA 79.85°±3.49°),下颌发育从正常至不同程度的发育过度(SNB 81.55°±3.71°).进行常规锥体束CT扫描,使用Dolphin软件完成41项牙、(牙合)、颌、面头影测量指标,完成上气道及其各区段的高度、截面积和体积测量.对上气道各项指标与患儿一般发育指标、头影测量各项指标进行相关分析.结果 年龄是上气道重要影响因素(r=0.417,P=0.020);颌骨硬组织指标Pg-NB、Co-Gn、Ar-Go、SGo,牙性指标U1-NA、L1-MP、OB对上气道大小的影响有统计学意义.结论 骨性指标与牙性指标均对上气道大小有影响,生长发育主要通过垂直向发育影响儿童上气道大小.

  11. Mechanical ventilation-induced intrathoracic pressure distribution and heart-lung interactions*

    NARCIS (Netherlands)

    Lansdorp, B.; Hofhuizen, C.M.; Lavieren, M. van; Swieten, H.A. van; Lemson, J.; Putten, M.J.A.M. van; Hoeven, J.G. van der; Pickkers, P.

    2014-01-01

    OBJECTIVE: Mechanical ventilation causes cyclic changes in the heart's preload and afterload, thereby influencing the circulation. However, our understanding of the exact physiology of this cardiopulmonary interaction is limited. We aimed to thoroughly determine airway pressure distribution, how thi

  12. The effect of short-term withdrawal from continuous positive airway pressure therapy on sympathetic activity and markers of vascular inflammation in subjects with obstructive sleep apnoea.

    Science.gov (United States)

    Phillips, Craig L; Yang, Qiao; Williams, Andrew; Roth, Michael; Yee, Brendon J; Hedner, Jan A; Berend, Norbert; Grunstein, Ronald R

    2007-06-01

    Obstructive sleep apnoea (OSA) is commonly associated with cardiovascular disease and sympathetic activation. However, it is unclear whether this association is independent of obesity and to what extent treatment with nasal continuous positive airway pressure (CPAP) alleviates the vascular inflammation that underpins cardiovascular disease. We therefore evaluated whether short-term withdrawal from CPAP therapy in subjects with moderate-severe OSA would result in increased levels of sympathetic activity and circulating inflammatory cytokines independent of weight. Vascular inflammatory markers (hsCRP, hsIL-6 and hsTNF-alpha) were assessed in 20 subjects after one and seven nights of withdrawal from CPAP together with the hypoxia-responsive angiogenic marker VEGF and urinary catecholamines. Compared with baseline on CPAP, withdrawal from therapy resulted in an immediate return of OSA with an increase in RDI to 26.7 +/- 5.2 and 39.0 +/- 5.9 events per hour after one and seven nights without CPAP, respectively (both P 0.1). In conclusion, 1 week of CPAP withdrawal was associated with a return of OSA and a marked increase in sympathetic activity without a concomitant elevation of vascular inflammatory markers.

  13. Impact of obstructive sleep apnea treatment by continuous positive airway pressure on cardiometabolic biomarkers: a systematic review from sham CPAP randomized controlled trials.

    Science.gov (United States)

    Jullian-Desayes, Ingrid; Joyeux-Faure, Marie; Tamisier, Renaud; Launois, Sandrine; Borel, Anne-Laure; Levy, Patrick; Pepin, Jean-Louis

    2015-06-01

    Reducing cardiometabolic risk may represent an important target for effective obstructive sleep apnea (OSA) treatment. The impact of continuous positive airway pressure (CPAP), the first line therapy of OSA, on metabolic or inflammatory markers is still debated. A systematic literature search using several databases was performed. We provide a systematic analysis of randomized studies comparing therapeutic versus sham CPAP intervention and also include studies using a CPAP withdrawal design. We addressed the impact of CPAP on the following cardiometabolic biomarkers: 1) plasma and urine catecholamines and their metabolites that reflect sympathetic activity; 2) insulin resistance and lipid metabolism biomarkers; 3) oxidative stress, systemic and vascular inflammation biomarkers; 4) liver enzymes highlighting the association between OSA and nonalcoholic fatty liver disease (NAFLD); 5) coagulation biomarkers. The impact of CPAP on sympathetic activity is robust across studies and occurs rapidly. In contrast to sympathetic activity, the well-designed studies included in this review failed to demonstrate that CPAP alters metabolic or inflammatory markers in OSA. CPAP did not change glucose, lipids, insulin resistance levels or the ratio of patients with metabolic syndrome. In unselected OSA patients, it is not realistic to expect a clinically relevant decrease in cardiometabolic biomarkers with CPAP therapy.

  14. Effects of Continuous Positive Airway Pressure on Cognitive Deficits in Middle-aged Patients with Obstructive Sleep Apnea Syndrome: A Meta-analysis of Randomized Controlled Trials

    Institute of Scientific and Technical Information of China (English)

    Yue-Ying Pan; Yan Deng; Xiu Xu; Ya-Ping Liu; Hui-Guo Liu

    2015-01-01

    Background:Current views on continuous positive airway pressure (CPAP) treatment to improve the cognitive deficits of patients with obstructive sleep apnea syndrome (OSAS) are controversial,so we performed a meta-analysis.Methods:A comprehensive literature search was tmdertaken in PubMed,CINAHL,Medline,PsycInfo,EMBASE,Cochrane Library,CNKI,WanFang,VIP,and CBMdisc for studies published from June 1971 to July 2014.The outcome measures included neuropsychological tests of the 7 cognitive domains detailed below.Results:After screening the titles and abstracts and thoroughly reading the full text,we obtained 13 studies with little risk of bias that incorporated 1744 middle-aged obese participants with mild to severe OSAS.The studies were published from 1994 to 2012.Treatment durations varied from 1 to 24 weeks.The effect sizes of attention,vigilance,processing speed,working memory,memory,verbal fluency,and visuoconstructive skills domains were-0.10 (P =0.24),-0.12 (P =0.04),-0.08 (P =0.16),0.00 (P =0.95),-0.04 (P =0.30),-0.06 (P =0.34),and-0.01 (P =0.92),respectively.Conclusions:Cognition partially improved in patients with OSAS after CPAP treatment.The only domain with significant improvement was vigilance.Rigorous randomized controlled trials need to be performed to obtain clear results.

  15. Effect of continuous positive airway pressure on arterial stiffness in patients with obstructive sleep apnea and hypertension: a meta-analysis.

    Science.gov (United States)

    Lin, Xin; Chen, Gongping; Qi, Jiachao; Chen, Xiaofang; Zhao, Jiangming; Lin, Qichang

    2016-12-01

    Arterial stiffness has been recognized as a predictor of cardiovascular and all-cause mortality in hypertensive patients. However, the impact of continuous positive airway pressure (CPAP) on arterial stiffness in patients with OSA and hypertension remains inconclusive. We performed a meta-analysis to determine whether effective CPAP therapy could decrease arterial stiffness. Two reviewers independently searched PubMed, Embase, Web of Science and Cochrane Library prior to March 5, 2015. Information on characteristics of subjects, study design and pre- and post-CPAP treatment of arterial stiffness was extracted for analysis. Standardized mean difference (SMD) was used to analyze the summary estimates for CPAP therapy. Three articles with 186 patients were included in this meta-analysis, including two observational studies and one randomized controlled study. The meta-analysis showed that CPAP was associated with a statistically significant decrease in arterial stiffness in patients with OSA and hypertension (SMD = -0.65, 95 % confidence interval (CI) = -1.14 to -0.16, z = 2.60, p = 0.009). Our meta-analysis suggested that CPAP among OSA and hypertensive patients was significantly associated with a decrease in arterial stiffness. Further prospective large-scale multicenter RCTs are needed to explore the precise impact of CPAP therapy on arterial stiffness in patients with OSA and hypertension.

  16. Adolescents with obstructive sleep apnea adhere poorly to positive airway pressure (PAP, but PAP users show improved attention and school performance.

    Directory of Open Access Journals (Sweden)

    Dean W Beebe

    Full Text Available BACKGROUND: Obstructive Sleep Apnea (OSA is associated with medical and neurobehavioral morbidity across the lifespan. Positive airway pressure (PAP treatment has demonstrated efficacy in treating OSA and has been shown to improve daytime functioning in adults, but treatment adherence can be problematic. There are nearly no published studies examining functional outcomes such as academic functioning in adolescents treated with PAP. This study was conducted as an initial step towards determining whether PAP treatment improves daytime functioning among adolescents with OSA. METHODS: Self-reported academic grades, self- and parent-reported academic quality of life, and objectively-measured attention were assessed before and after PAP was clinically initiated in a sample of 13 obese adolescents with OSA, as well as 15 untreated obese Controls without OSA. Based on adherence data, the treated group was divided into PAP Users (n = 6 and Non-Adherent participants (n = 7. RESULTS: Though demographically similar, the three groups significantly differed in how their academic performance and attention scores changed from baseline to follow-up. Non-Adherent participants showed worsening functioning over time, while PAP Users showed stable or improved functioning, similar to controls. CONCLUSION: Although many adolescents prescribed PAP for OSA are non-adherent to the treatment, those who adhere to treatment can display improved attention and academic functioning.

  17. Estimation of airway obstruction using oximeter plethysmograph waveform data

    Directory of Open Access Journals (Sweden)

    Desmond Renee' A

    2005-06-01

    Full Text Available Abstract Background Validated measures to assess the severity of airway obstruction in patients with obstructive airway disease are limited. Changes in the pulse oximeter plethysmograph waveform represent fluctuations in arterial flow. Analysis of these fluctuations might be useful clinically if they represent physiologic perturbations resulting from airway obstruction. We tested the hypothesis that the severity of airway obstruction could be estimated using plethysmograph waveform data. Methods Using a closed airway circuit with adjustable inspiratory and expiratory pressure relief valves, airway obstruction was induced in a prospective convenience sample of 31 healthy adult subjects. Maximal change in airway pressure at the mouthpiece was used as a surrogate measure of the degree of obstruction applied. Plethysmograph waveform data and mouthpiece airway pressure were acquired for 60 seconds at increasing levels of inspiratory and expiratory obstruction. At each level of applied obstruction, mean values for maximal change in waveform area under the curve and height as well as maximal change in mouth pressure were calculated for sequential 7.5 second intervals. Correlations of these waveform variables with mouth pressure values were then performed to determine if the magnitude of changes in these variables indicates the severity of airway obstruction. Results There were significant relationships between maximal change in area under the curve (P Conclusion The findings suggest that mathematic interpretation of plethysmograph waveform data may estimate the severity of airway obstruction and be of clinical utility in objective assessment of patients with obstructive airway diseases.

  18. Efficiency of Continuous Positive Airway Pressure or High-Frequency Jet Ventilation by Means a Nasooral Mask in the Treatment of Pulmonary Edema

    Directory of Open Access Journals (Sweden)

    J. Salantay

    2008-01-01

    Full Text Available Objective: to compare the efficiency of continuous positive airway pressure (CPAP and high-frequency jet ventilation by means of a mask (HFJV-M in the treatment of cardiogenic edema of the lung. Design: a retrospective study. Setting: Department of Anesthesiology and Intensive Medicine, Hospital NsP, Vranov, Slovakia. Subjects and methods. A hundred and ninety-six patients with varying cardiogenic edema of the lung were divided into 3 groups according to the severity of pulmonary edema (PE. By taking into account comparable pharmacotherapy, mean airway pressure, and FiO2, the authors compared the efficiency of CPAP (n=64 and HFJV-M (n=101 from the rate of changes in respiration rate, blood oxygenation, acid-base balance, and the duration of ventilation support and the length of stay in the intensive care unit (ICU. The results were assessed by the unpaired Student’s test. The procedure of artificial ventilation via HFJV-M was approved by the Professional and Ethics Committee, Ministry of Health in the Republic of Slovakia, in 1989 for clinical application. Results. Comparison of CPAP or HFJV-M used in mild PE that was called Phase 1 of PE revealed no statistically significant differences in the parameters being assessed. In severer forms of PE characterized as Phases 2 and 3, the use of HFJV-M in the first 3 hours of ventilation maintenance caused a rapider reduction in spontaneous respiration rate from 25—33 per min to 18—22 per min (p>0.01. The application of HFJV-M also showed a statistically significant difference in the correction rate of PaO2, pH, and oxygenation index (PaO2/FIO2 (p>0.01 predominantly within the first 2 hours of therapy. Comparison of the mean duration of necessary ventilation maintenance (CPAP versus HFJV-M: 10.9 versus 6.8 hours and the mean length of stay in the ICU (CPAP versus HFJV-N: 2.7 versus 2 days revealed a statistically significant difference (p>0.01 and p>0.05, respectively. Only 6.6% of the HFJV-M group

  19. Effects of heated humidification and topical steroids on compliance, nasal symptoms, and quality of life in patients with obstructive sleep apnea syndrome using nasal continuous positive airway pressure.

    LENUS (Irish Health Repository)

    Ryan, Silke

    2012-02-01

    BACKGROUND: Nasal side effects are common in patients with obstructive sleep apnea syndrome (OSAS) starting on nasal continuous positive airway pressure (CPAP) therapy. We tested the hypothesis that heated humidification or nasal topical steroids improve compliance, nasal side effects and quality of life in this patient group. METHODS: 125 patients with the established diagnosis of OSAS (apnea\\/hypopnea index > or = 10\\/h), who tolerated CPAP via a nasal mask, and who had a successful CPAP titration were randomized to 4 weeks of dry CPAP, humidified CPAP or CPAP with additional topical nasal steroid application (fluticasone, GlaxoWellcome). Groups were similar in all demographic variables and in frequency of nasal symptoms at baseline. Outcome measures were objective compliance, quality of life (short form 36), subjective sleepiness (Epworth Sleepiness Scale score) and nasal symptoms such as runny, dry or blocked nose, sneezing and headaches; all variables assessed using a validated questionnaire and by direct interview. RESULTS: There was no difference in compliance between groups after 4 weeks (dry: 5.21 +\\/- 1.66 h\\/night, fluticasone: 5.66 +\\/- 1.68, humidifier: 5.21 +\\/- 1.84; p = 0.444). Quality of life and subjective sleepiness improved in all groups, but there were no differences in the extent of improvement. Nasal Symptoms were less frequently reported in the humidifier group (28%) than in the remaining groups (dry: 70%, fluticasone: 53%, p = 0.002). However, the addition of fluticasone resulted in increased frequency of sneezing. CONCLUSION: The addition of a humidifier, but not nasal steroids decreases the frequency of nasal symptoms in unselected OSAS patients initiating CPAP therapy; however compliance and quality of life remain unaltered.

  20. Nurse-led intensive interventions improve adherence to continuous positive airway pressure therapy and quality of life in obstructive sleep apnea patients

    Directory of Open Access Journals (Sweden)

    Chen XF

    2015-11-01

    Full Text Available Xiaofen Chen,1 Weiting Chen,1 Weijie Hu,2 Kui Huang,3 Jing Huang,4 Yu Zhou5 1Hospital of Stomatology, Wenzhou Medical University, Wenzhou, 2People Hospital of Tiantai, Taizhou, 3Department of Orthodontics, Hospital of Stomatology, Wenzhou Medical University, Wenzhou, 4The Second Affiliated Hospital Zhejiang University School of Medicine, Hangzhou, 5Department of Orthodontics, Hospital of Stomatology, Wenzhou Medical University, Wenzhou, People’s Republic of China Background: Continuous positive airway pressure (CPAP is widely recommended for the treatment of sleep apnea/hypopnea syndrome (SAHS, but its usage by patients is very low. The aim of this study was to assess intensive educational programs and nursing support for the improvement of CPAP use and outcomes in SAHS patients.Methods: Eighty new SAHS patients were randomized to receive nurse-led intensive interventions or usual support at hospital and home. The main outcome measure was CPAP use; changes in sleeping, symptoms, mood, and quality of life were also assessed after 12 months of treatment.Results: All outcome measures were improved after treatment in both groups. However, patients receiving intensive support with significantly higher CPAP use (higher daily CPAP usage by 2.2 hours/day had greater improvements in SAHS symptoms and mood (P<0.05. The intervention group further showed an improvement in the Short Form-36 domains of mental and physical health (P<0.05.Conclusion: The CPAP usage and quality of life can be significantly improved by nurse-led intensive program in obstructive sleep apnea patients. Keywords: CPAP, quality of life, SAHS, compliance

  1. The Effects of Massage with Coconut and Sunflower Oils on Oxygen Saturation of Premature Infants with Respiratory Distress Syndrome Treated With Nasal Continuous Positive Airway Pressure

    Directory of Open Access Journals (Sweden)

    Sousan Valizadeh

    2012-11-01

    Full Text Available Introduction: Nowadays particular emphasis is placed on the developmental aspects of premature infants care. Massage therapy is one of the best-known methods of caring. Due to the minimal touch policy in neonatal intensive care units (NICUs, massaging is not usually performed on premature infants. However, there is not sufficient evidence to support the claim that newborn infants with complex medical conditions should not be massaged. This study aimed to determine the effects of massage with coconut and sunflower oils on oxygen saturation of infants with respiratory distress syndrome (RDS treated with nasal continuous positive airway pressure (NCPAP. Methods: This was a randomized controlled trial on 90 newborns who were admitted to Alzahra Hospital (Tabriz, Iran. The infants were divided into control and massage therapy groups (massage with coconut and sunflower oils. Data was collected using a hospital documentation form. A 15-minute daily massage was performed for 3 days. Respiratory rate (RR, fraction of inspired oxygen (FiO2 and oxygen saturation were measured 5 minutes before the massage, 3 times during the massage, and 5 minutes after the massage. The collected data was analyzed using a mixed model. Results: In comparison to coconut oil and control groups, mean oxygen saturation of sunflower oil group was improved. In addition, the coconut massage group showed lower oxygen saturation than the control group but was all values were within the normal range. Although massage decreased oxygen saturation, there was no need to increase FiO2. Conclusion: Massage therapy can provide developmental care for infants treated with NCPAP.

  2. Postoperative pharyngolaryngeal adverse events with laryngeal mask airway (LMA Supreme) in laparoscopic surgical procedures with cuff pressure limiting 25 cmH₂O: prospective, blind, and randomised study.

    Science.gov (United States)

    Kang, Joo-Eun; Oh, Chung-Sik; Choi, Jae Won; Son, Il Soon; Kim, Seong-Hyop

    2014-01-01

    To reduce the incidence of postoperative pharyngolaryngeal adverse events, laryngeal mask airway (LMA) manufacturers recommend maximum cuff pressures not exceeding 60 cmH₂O. We performed a prospective randomised study, comparing efficacy and adverse events among patients undergoing laparoscopic surgical procedures who were allocated randomly into low (limiting 25 cmH₂O, L group) and high (at 60 cmH₂O, H group) LMA cuff pressure groups with LMA Supreme. Postoperative pharyngolaryngeal adverse events were evaluated at discharge from postanaesthetic care unit (PACU) (postoperative day 1, POD 1) and 24 hours after discharge from PACU (postoperative day 2, POD 2). All patients were well tolerated with LMA without ventilation failure. Before pneumoperitoneum, cuff volume and pressure and oropharyngeal leak pressure (OLP) showed significant differences. Postoperative sore throat at POD 2 (3 versus 12 patients) and postoperative dysphagia at POD 1 and POD 2 (0 versus 4 patients at POD 1; 0 versus 4 patients at POD 2) were significantly lower in L group, compared with H group. In conclusion, LMA with cuff pressure limiting 25 cmH₂O allowed both efficacy of airway management and lower incidence of postoperative adverse events in laparoscopic surgical procedures. This clinical trial is registered with KCT0000334.

  3. Upper airway collapsibility in anesthetized children.

    Science.gov (United States)

    Litman, Ronald S; McDonough, Joseph M; Marcus, Carole L; Schwartz, Alan R; Ward, Denham S

    2006-03-01

    We sought to establish the feasibility of measuring upper airway narrowing in spontaneously breathing, anesthetized children using dynamic application of negative airway pressure. A secondary aim was to compare differences in upper airway collapsibility after the administration of sevoflurane or halothane. Subjects were randomized to either drug for inhaled anesthetic induction. Each was adjusted to their 1 MAC value (0.9% for halothane and 2.5% for sevoflurane) and a blinded anesthesia provider held the facemask without performing manual airway opening maneuvers but with inclusion of an oral airway device. Inspiratory flows were measured during partial upper airway obstruction created by an adjustable negative pressure-generating vacuum motor inserted into the anesthesia circuit. Critical closing pressure of the pharynx (Pcrit) was obtained by plotting the peak inspiratory flow of the obstructed breaths against the corresponding negative pressure in the facemask and extrapolating to zero airflow using linear correlation. Fourteen children were enrolled, seven in each anesthetic group. Two children in the halothane group did not develop flow-limited airway obstruction despite negative pressures as low as -9 cm H2O. Pcrit for sevoflurane ranged from -6.7 to -11.6 (mean +/- sd, -9.8 +/- 1.9) cm H2O. Pcrit for halothane ranged from -8.1 to -33 (mean +/- sd, -19.4 +/- 9.3) cm H2O (sevoflurane versus halothane, P = 0.048). We conclude that when using dynamic application of negative airway pressure, halothane appears to cause less upper airway obstruction than sevoflurane at equipotent concentrations.

  4. Intracranial Pressure Influences the Behavior of the Optic Nerve Head.

    Science.gov (United States)

    Hua, Yi; Tong, Junfei; Ghate, Deepta; Kedar, Sachin; Gu, Linxia

    2017-03-01

    In this work, the biomechanical responses of the optic nerve head (ONH) to acute elevations in intracranial pressure (ICP) were systematically investigated through numerical modeling. An orthogonal experimental design was developed to quantify the influence of ten input factors that govern the anatomy and material properties of the ONH on the peak maximum principal strain (MPS) in the lamina cribrosa (LC) and postlaminar neural tissue (PLNT). Results showed that the sensitivity of ONH responses to various input factors was region-specific. In the LC, the peak MPS was most strongly dependent on the sclera thickness, LC modulus, and scleral canal size, whereas in the PLNT, the peak MPS was more sensitive to the scleral canal size, neural tissue modulus, and pia mater modulus. The enforcement of clinically relevant ICP in the retro-orbital subarachnoid space influenced the sensitivity analysis. It also induced much larger strains in the PLNT than in the LC. Moreover, acute elevation of ICP leads to dramatic strain distribution changes in the PLNT, but had minimal impact on the LC. This work could help to better understand patient-specific responses, to provide guidance on biomechanical factors resulting in optic nerve diseases, such as glaucoma, papilledema, and ischemic optic neuropathy, and to illuminate the possibilities for exploiting their potential to treat and prevent ONH diseases.

  5. Bronchoconstriction and airway biology : potential impact and therapeutic opportunities

    NARCIS (Netherlands)

    Gosens, Reinoud; Grainge, Chris

    2015-01-01

    Recent work has demonstrated that mechanical forces occurring in the airway as a consequence of bronchoconstriction are sufficient to not only induce symptoms but also influence airway biology. Animal and human in vitro and in vivo work demonstrates that the airways are structurally and functionally

  6. Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk

    NARCIS (Netherlands)

    G.B. Ehret (Georg); P. Munroe (Patricia); K.M. Rice (Kenneth); M. Bochud (Murielle); A.D. Johnson (Andrew); D.I. Chasman (Daniel); A.V. Smith (Albert Vernon); M.D. Tobin (Martin); G.C. Verwoert (Germaine); S.J. Hwang; V. Pihur (Vasyl); P. Vollenweider (Peter); P.F. O'Reilly (Paul); N. Amin (Najaf); J.L. Bragg-Gresham (Jennifer L.); A. Teumer (Alexander); N.L. Glazer (Nicole); L.J. Launer (Lenore); J. Hua Zhao (Jing); Y.S. Aulchenko (Yurii); S.C. Heath (Simon); S. Sõber (Siim); A. Parsa (Afshin); J. Luan; P. Arora (Pankaj); A. Dehghan (Abbas); F. Zhang (Feng); G. Lucas (Gavin); A.A. Hicks (Andrew); A.U. Jackson (Anne); J. Peden (John); T. Tanaka (Toshiko); S.H. Wild (Sarah); I. Rudan (Igor); W. Igl (Wilmar); Y. Milaneschi (Yuri); A.N. Parker (Alex); C. Fava (Cristiano); J.C. Chambers (John); E.R. Fox (Ervin); M. Kumari (Meena); M. Jin Go (Min); P. van der Harst (Pim); W. Hong Linda Kao (Wen); M. Sjögren (Marketa); D.G. Vinay; M. Alexander (Myriam); Y. Tabara (Yasuharu); S. Shaw-Hawkins (Sue); P.H. Whincup (Peter); Y. Liu (Yongmei); G. Shi (Gang); J. Kuusisto (Johanna); B. Tayo (Bamidele); M. Seielstad (Mark); X. Sim (Xueling); K.-D. Hoang Nguyen; T. Lehtimäki (Terho); G. Matullo (Giuseppe); Y. Wu (Ying); T.R. Gaunt (Tom); N. Charlotte Onland-Moret; M.N. Cooper (Matthew); C. Platou (Carl); E. Org (Elin); R. Hardy (Rebecca); S. Dahgam (Santosh); J. Palmen (Jutta); V. Vitart (Veronique); P.S. Braund (Peter); T. Kuznetsova (Tatiana); C.S.P.M. Uiterwaal (Cuno); A. Adeyemo (Adebowale); W. Palmas (Walter); H. Campbell (Harry); B. Ludwig (Barbara); M. Tomaszewski; I. Tzoulaki; N.D. Palmer (Nicholette); T. Aspelund (Thor); M. Garcia (Melissa); Y.-P.C. Chang (Yen-Pei); J.R. O´Connell; N.I. Steinle (Nanette); D.E. Grobbee (Diederick); D.E. Arking (Dan); S.L. Kardia (Sharon); A.C. Morrison (Alanna); D.G. Hernandez (Dena); S.S. Najjar (Samer); W.L. McArdle (Wendy); D. Hadley (David); M.J. Brown (Morris); J. Connell (John); A. Hingorani (Aroon); I.N.M. Day (Ian); D.A. Lawlor (Debbie); J.P. Beilby (John); R.W. Lawrence (Robert); R. Clarke; J. Hopewell; H. Ongen (Halit); A.W. Dreisbach (Albert); Y. Li (Yali); J. Hunter Young; J.C. Bis (Joshua); M. Kähönen (Mika); J. Viikari (Jorma); N.R. Lee (Nanette); M-H. Chen (Ming-Huei); M. Olden (Matthias); C. Pattaro (Cristian); J.A. Hoffman Bolton (Judith); A. Köttgen (Anna); S.M. Bergmann (Sven); V. Mooser (Vincent); N. Chaturvedi (Nish); T.M. Frayling (Timothy); M. Islam (Muhammad); T.H. Jafar (Tazeen); S.R. Kulkarni (Smita); S.R. Bornstein (Stefan); J. Gräßler (Jürgen); L. Groop (Leif); B.F. Voight (Benjamin); J. Kettunen (Johannes); P. Howard (Philip); A. Taylor (Andrew); S. Guarrera (Simonetta); F. Ricceri (Fulvio); V. Emilsson (Valur); A.S. Plump (Andrew); K-T. Khaw (Kay-Tee); A.B. Weder (Alan); S.C. Hunt (Steven); Y.V. Sun (Yan); R.N. Bergman (Richard); F.S. Collins (Francis); L.L. Bonnycastle (Lori); L.J. Scott (Laura); H.M. Stringham (Heather); L. Peltonen (Leena Johanna); M. Perola (Markus); E. Vartiainen (Erkki); S.-M. Brand; J.A. Staessen (Jan); Y.A. Wang (Ying); P.R. Burton (Paul); M. Soler Artigas (Maria); Y. Dong (Yanbin); H. Snieder (Harold); H. Zhu (Haidong); K. Lohman (Kurt); M.E. Rudock (Megan); S.R. Heckbert (Susan); K.L. Wiggins (Kerri); A. Doumatey (Ayo); D. Shriner (Daniel); G. Veldre (Gudrun); M. Viigimaa (Margus); S. Kinra (Sanjay); D. Prabhakaran (Dorairaj); V. Tripathy (Vikal); C.D. Langefeld (Carl); A. Rosengren (Annika); D.S. Thelle (Dag); A. Maria Corsi (Anna); A. Singleton (Andrew); T. Forrester (Terrence); G. Hilton (Gina); C.A. McKenzie (Colin); T. Salako (Tunde); N. Iwai (Naoharu); Y. Kita (Yoshikuni); T. Ogihara (Toshio); T. Ohkubo (Takayoshi); T. Okamura (Tomonori); H. Ueshima (Hirotsugu); S. Umemura (Satoshi); S. Eyheramendy (Susana); T. Meitinger (Thomas); H.E. Wichmann (Heinz Erich); Y. Shin Cho (Yoon); H.-L. Kim; J.S. Sehmi (Joban); B. Hedblad (Bo); P. Nilsson (Peter); G. Davey-Smith (George); A. Wong (Andrew); N. Narisu (Narisu); A. Stancáková (Alena); L.J. Raffel (Leslie); J. Yao (Jie); S. Kathiresan (Sekar); C.J. O'Donnell (Christopher); S.M. Schwartz (Stephen); M.A. Ikram (Arfan); W.T. Longstreth Jr; T.H. Mosley (Thomas); S. Seshadri (Sudha); N.R.G. Shrine (Nick); L.V. Wain (Louise); M.A. Morken (Mario); A.J. Swift (Amy); J. Laitinen (Jaana); I. Prokopenko (Inga); P. Zitting (Paavo); S.E. Humphries (Steve); J. Danesh (John); A. Rasheed (Asif); A. Goel (Anuj); A. Hamsten (Anders); H. Watkins (Hugh); W.H. van Gilst (Wiek); C.S. Janipalli (Charles); K. Radha Mani; C. Yajnik (Chittaranjan); A. Hofman (Albert); F.U.S. Mattace Raso (Francesco); B.A. Oostra (Ben); A. Demirkan (Ayşe); A.J. Isaacs (Aaron); F. Rivadeneira Ramirez (Fernando); E. Lakatta (Edward); M. Orrù (Marco); A. Scuteri (Angelo); M. Ala-Korpela (Mika); A.J. Kangas (Antti); L.-P. Lyytikäinen (Leo-Pekka); P. Soininen (Pasi); T. Tukiainen (Taru); P. Würtz (Peter); R. Twee-Hee Ong (Rick); M. Dörr (Marcus); H.K. Kroemer (Heyo); U. Völker (Uwe); H. Völzke (Henry); P. Galan (Pilar); S. Hercberg (Serge); G.M. Lathrop (Mark); D. Zelenika (Diana); P. Deloukas (Panagiotis); M. Mangino (Massimo); T.D. Spector (Timothy); G. Zhai (Guangju); J.F. Meschia (James F.); M.A. Nalls (Michael); P. Sharma (Pankaj); J. Terzic (Janos); M.V. Kranthi Kumar; M. Denniff (Matthew); E. Zukowska-Szczechowska (Ewa); L.E. Wagenknecht (Lynne); F. Gerald R. Fowkes; F.J. Charchar (Fadi); P.E.H. Schwarz (Peter); C. Hayward (Caroline); X. Guo (Xiuqing); C. Rotimi (Charles); M.L. Bots (Michiel); N.J. Samani (Nilesh); O. Polasek (Ozren); P.J. Talmud (Philippa); F. Nyberg (Fredrik); D. Kuh (Diana); M. Laan (Maris); K. Hveem (Kristian); Y.T. van der Schouw (Yvonne); J.P. Casas (Juan); K.L. Mohlke (Karen); P. Vineis (Paolo); O. Raitakari (Olli); S.K. Ganesh (Santhi); E. Shyong Tai; M. Laakso (Markku); D.C. Rao (Dabeeru C.); T.B. Harris (Tamara); R.W. Morris (Richard); A. Dominiczak (Anna); M. Kivimaki (Mika); M. Marmot (Michael); T. Miki (Tetsuro); D. Saleheen; G.R. Chandak (Giriraj); J. Coresh (Josef); G. Navis (Gerjan); V. Salomaa (Veikko); B.-G. Han; J.S. Kooner (Jaspal); O. Melander (Olle); P.M. Ridker (Paul); S. Bandinelli (Stefania); U. Gyllensten (Ulf); A.F. Wright (Alan); J.F. Wilson (James); L. Ferrucci (Luigi); M. Farrall (Martin); J. Tuomilehto (Jaakko); P.P. Pramstaller (Peter Paul); R. Elosua (Roberto); N. Soranzo (Nicole); E.J.G. Sijbrands (Eric); D. Altshuler (David); R.J.F. Loos (Ruth); A.R. Shuldiner (Alan); C. Gieger (Christian); P. Meneton (Pierre); A.G. Uitterlinden (André); N.J. Wareham (Nick); V. Gudnason (Vilmundur); J.I. Rotter (Jerome); R. Rettig (Rainer); M. Uda (Manuela); D.P. Strachan (David); J.C.M. Witteman (Jacqueline); A.L. Hartikainen; J.S. Beckmann (Jacques); E.A. Boerwinkle (Eric); J. Erdmann (Jeanette); R.S. Vasan (Ramachandran Srini); M. Boehnke (Michael); M.G. Larson (Martin); M.R. Järvelin; B.M. Psaty (Bruce); P. Tikka-Kleemola (Päivi); C. Newton-Cheh (Christopher); P. Elliott (Paul); D. Levy (Daniel); M. Caulfield (Mark); G.R. Abecasis (Gonçalo); L.S. Adair (Linda); S.J.L. Bakker (Stephan); I. Barroso (Inês)

    2011-01-01

    textabstractBlood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140mmg Hg systolic blood pressure ≥90mmg Hg diastolic blood pressure). Even small increments in blood pressure are

  7. Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk

    NARCIS (Netherlands)

    Ehret, Georg B.; Munroe, Patricia B.; Rice, Kenneth M.; Bochud, Murielle; Johnson, Andrew D.; Chasman, Daniel I.; Smith, Albert V.; Tobin, Martin D.; Verwoert, Germaine C.; Hwang, Shih-Jen; Pihur, Vasyl; Vollenweider, Peter; O'Reilly, Paul F.; Amin, Najaf; Bragg-Gresham, Jennifer L.; Teumer, Alexander; Glazer, Nicole L.; Launer, Lenore; Zhao, Jing Hua; Aulchenko, Yurii; Heath, Simon; Sober, Siim; Parsa, Afshin; Luan, Jian'an; Arora, Pankaj; Dehghan, Abbas; Zhang, Feng; Lucas, Gavin; Hicks, Andrew A.; Jackson, Anne U.; Peden, John F.; Tanaka, Toshiko; Wild, Sarah H.; Rudan, Igor; Igl, Wilmar; Milaneschi, Yuri; Parker, Alex N.; Fava, Cristiano; Chambers, John C.; Fox, Ervin R.; Kumari, Meena; Go, Min Jin; van der Harst, Pim; Kao, Wen Hong Linda; Sjogren, Marketa; Vinay, D. G.; Alexander, Myriam; Tabara, Yasuharu; Shaw-Hawkins, Sue; Whincup, Peter H.; Liu, Yongmei; Shi, Gang; Kuusisto, Johanna; Tayo, Bamidele; Seielstad, Mark; Sim, Xueling; Khanh-Dung Hoang Nguyen, [No Value; Lehtimaki, Terho; Matullo, Giuseppe; Wu, Ying; Gaunt, Tom R.; Onland-Moret, N. Charlotte; Cooper, Matthew N.; Platou, Carl G. P.; Org, Elin; Hardy, Rebecca; Dahgam, Santosh; Palmen, Jutta; Vitart, Veronique; Braund, Peter S.; Kuznetsova, Tatiana; Uiterwaal, Cuno S. P. M.; Adeyemo, Adebowale; Palmas, Walter; Campbell, Harry; Ludwig, Barbara; Tomaszewski, Maciej; Tzoulaki, Ioanna; Palmer, Nicholette D.; Aspelund, Thor; Garcia, Melissa; Chang, Yen-Pei C.; O'Connell, Jeffrey R.; Steinle, Nanette I.; Grobbee, Diederick E.; Arking, Dan E.; Kardia, Sharon L.; Morrison, Alanna C.; Hernandez, Dena; Najjar, Samer; McArdle, Wendy L.; Hadley, David; Brown, Morris J.; Connell, John M.; Hingorani, Aroon D.; Day, Ian N. M.; Lawlor, Debbie A.; Beilby, John P.; Lawrence, Robert W.; Clarke, Robert; Hopewell, Jemma C.; Ongen, Halit; Dreisbach, Albert W.; Li, Yali; Young, J. Hunter; Bis, Joshua C.; Kahonen, Mika; Viikari, Jorma; Adair, Linda S.; Lee, Nanette R.; Chen, Ming-Huei; Olden, Matthias; Pattaro, Cristian; Bolton, Judith A. Hoffman; Koettgen, Anna; Bergmann, Sven; Mooser, Vincent; Chaturvedi, Nish; Frayling, Timothy M.; Islam, Muhammad; Jafar, Tazeen H.; Erdmann, Jeanette; Kulkarni, Smita R.; Bornstein, Stefan R.; Graessler, Juergen; Groop, Leif; Voight, Benjamin F.; Kettunen, Johannes; Howard, Philip; Taylor, Andrew; Guarrera, Simonetta; Ricceri, Fulvio; Emilsson, Valur; Plump, Andrew; Barroso, Ine S.; Khaw, Kay-Tee; Weder, Alan B.; Hunt, Steven C.; Sun, Yan V.; Bergman, Richard N.; Collins, Francis S.; Bonnycastle, Lori L.; Scott, Laura J.; Stringham, Heather M.; Peltonen, Leena; Perola, Markus; Vartiainen, Erkki; Brand, Stefan-Martin; Staessen, Jan A.; Wang, Thomas J.; Burton, Paul R.; Artigas, Maria Soler; Dong, Yanbin; Snieder, Harold; Wang, Xiaoling; Zhu, Haidong; Lohman, Kurt K.; Rudock, Megan E.; Heckbert, Susan R.; Smith, Nicholas L.; Wiggins, Kerri L.; Doumatey, Ayo; Shriner, Daniel; Veldre, Gudrun; Viigimaa, Margus; Kinra, Sanjay; Prabhakaran, Dorairaj; Tripathy, Vikal; Langefeld, Carl D.; Rosengren, Annika; Thelle, Dag S.; Corsi, Anna Maria; Singleton, Andrew; Forrester, Terrence; Hilton, Gina; McKenzie, Colin A.; Salako, Tunde; Iwai, Naoharu; Kita, Yoshikuni; Ogihara, Toshio; Ohkubo, Takayoshi; Okamura, Tomonori; Ueshima, Hirotsugu; Umemura, Satoshi; Eyheramendy, Susana; Meitinger, Thomas; Wichmann, H. -Erich; Cho, Yoon Shin; Kim, Hyung-Lae; Lee, Jong-Young; Scott, James; Sehmi, Joban S.; Zhang, Weihua; Hedblad, Bo; Nilsson, Peter; Smith, George Davey; Wong, Andrew; Narisu, Narisu; Stancakova, Alena; Raffel, Leslie J.; Yao, Jie; Kathiresan, Sekar; O'Donnell, Christopher J.; Schwartz, Stephen M.; Ikram, M. Arfan; Longstreth, W. T.; Mosley, Thomas H.; Seshadri, Sudha; Shrine, Nick R. G.; Wain, Louise V.; Morken, Mario A.; Swift, Amy J.; Laitinen, Jaana; Prokopenko, Inga; Zitting, Paavo; Cooper, Jackie A.; Humphries, Steve E.; Danesh, John; Rasheed, Asif; Goel, Anuj; Hamsten, Anders; Watkins, Hugh; Bakker, Stephan J. L.; van Gilst, Wiek H.; Janipalli, Charles S.; Mani, K. Radha; Yajnik, Chittaranjan S.; Hofman, Albert; Mattace-Raso, Francesco U. S.; Oostra, Ben A.; Demirkan, Ayse; Isaacs, Aaron; Rivadeneira, Fernando; Lakatta, Edward G.; Orru, Marco; Scuteri, Angelo; Ala-Korpela, Mika; Kangas, Antti J.; Lyytikainen, Leo-Pekka; Soininen, Pasi; Tukiainen, Taru; Wurtz, Peter; Ong, Rick Twee-Hee; Doerr, Marcus; Kroemer, Heyo K.; Voelker, Uwe; Voelzke, Henry; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Zelenika, Diana; Deloukas, Panos; Mangino, Massimo; Spector, Tim D.; Zhai, Guangju; Meschia, James F.; Nalls, Michael A.; Sharma, Pankaj; Terzic, Janos; Kumar, M. V. Kranthi; Denniff, Matthew; Zukowska-Szczechowska, Ewa; Wagenknecht, Lynne E.; Fowkes, F. Gerald R.; Charchar, Fadi J.; Schwarz, Peter E. H.; Hayward, Caroline; Guo, Xiuqing; Rotimi, Charles; Bots, Michiel L.; Brand, Eva; Samani, Nilesh J.; Polasek, Ozren; Talmud, Philippa J.; Nyberg, Fredrik; Kuh, Diana; Laan, Maris; Hveem, Kristian; Palmer, Lyle J.; van der Schouw, Yvonne T.; Casas, Juan P.; Mohlke, Karen L.; Vineis, Paolo; Raitakari, Olli; Ganesh, Santhi K.; Wong, Tien Y.; Tai, E. Shyong; Cooper, Richard S.; Laakso, Markku; Rao, Dabeeru C.; Harris, Tamara B.; Morris, Richard W.; Dominiczak, Anna F.; Kivimaki, Mika; Marmot, Michael G.; Miki, Tetsuro; Saleheen, Danish; Chandak, Giriraj R.; Coresh, Josef; Navis, Gerjan; Salomaa, Veikko; Han, Bok-Ghee; Zhu, Xiaofeng; Kooner, Jaspal S.; Melander, Olle; Ridker, Paul M.; Bandinelli, Stefania; Gyllensten, Ulf B.; Wright, Alan F.; Wilson, James F.; Ferrucci, Luigi; Farrall, Martin; Tuomilehto, Jaakko; Pramstaller, Peter P.; Elosua, Roberto; Soranzo, Nicole; Sijbrands, Eric J. G.; Altshuler, David; Loos, Ruth J. F.; Shuldiner, Alan R.; Gieger, Christian; Meneton, Pierre; Uitterlinden, Andre G.; Wareham, Nicholas J.; Gudnason, Vilmundur; Rotter, Jerome I.; Rettig, Rainer; Uda, Manuela; Strachan, David P.; Witteman, Jacqueline C. M.; Hartikainen, Anna-Liisa; Beckmann, Jacques S.; Boerwinkle, Eric; Vasan, Ramachandran S.; Boehnke, Michael; Larson, Martin G.; Jarvelin, Marjo-Riitta; Psaty, Bruce M.; Abecasis, Goncalo R.; Chakravarti, Aravinda; Elliott, Paul; van Duijn, Cornelia M.; Newton-Cheh, Christopher; Levy, Daniel; Caulfield, Mark J.; Johnson, Toby

    2011-01-01

    Blood pressure is a heritable trait(1) influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (>= 140 mm Hg systolic blood pressure or >= 90 mm Hg diastolic blood pressure)(2). Even small increments in blood pressure are

  8. Wire-guided (Seldinger technique) intubation through a face mask in urgent, difficult and grossly distorted airways.

    Science.gov (United States)

    Heier, Jake M; Schroeder, Kristopher M; Galgon, Richard E; Arndt, George A

    2012-07-01

    We report two cases of successful urgent intubation using a Seldinger technique for airway management through an anesthesia facemask, while maintaining ventilation in patients with difficult airways and grossly distorted airway anatomy. In both cases, conventional airway management techniques were predicted to be difficult or impossible, and a high likelihood for a surgical airway was present. This technique was chosen as it allows tracheal tube placement through the nares during spontaneous ventilation with the airway stented open and oxygen delivery with either continuous positive airway pressure and/or pressure support ventilation. This unhurried technique may allow intubation when other techniques are unsuitable, while maintaining control of the airway.

  9. Wire-guided (Seldinger technique intubation through a face mask in urgent, difficult and grossly distorted airways

    Directory of Open Access Journals (Sweden)

    Jake M Heier

    2012-01-01

    Full Text Available We report two cases of successful urgent intubation using a Seldinger technique for airway management through an anesthesia facemask, while maintaining ventilation in patients with difficult airways and grossly distorted airway anatomy. In both cases, conventional airway management techniques were predicted to be difficult or impossible, and a high likelihood for a surgical airway was present. This technique was chosen as it allows tracheal tube placement through the nares during spontaneous ventilation with the airway stented open and oxygen delivery with either continuous positive airway pressure and/or pressure support ventilation. This unhurried technique may allow intubation when other techniques are unsuitable, while maintaining control of the airway.

  10. Ventilación con liberación de presión en la vía aérea, en neonatos con insuficiencia respiratoria aguda Airway pressure release ventilation in newborns

    Directory of Open Access Journals (Sweden)

    Emmanuel Jiménez-Castro

    2013-06-01

    Full Text Available La ventilación con liberación de presión en la vía aérea (APRVes una modalidad ventilatoria que utiliza presión positiva controlada en la vía aérea, con el fin de maximizar el reclutamiento alveolar, con tiempos inspiratorios prolongados, permitiendo la respiración espontánea durante ambas fases del ciclo respiratorio. Los autores describen su experiencia en una serie de 12 casos con pacientes neonatales con insuficiencia respiratoria aguda, que fueron tratados con la APRV ventilación con liberación de presión en la vía aérea, cuando la oxigenación no mejoró con la ventilación de control de presión. La edad media de los pacientes fue de 13± 16,5 días. La fracción inspirada de oxígeno disminuyó de 62,9±23,6 cm H2O para la ventilación de control de presión, a 44±14,0 cm H2O, para la APRV. El promedio de presión parcial de oxígenoaumentó de 54,6 ± 11,9mmHg a 92±32mmH; el promedio de presión parcial de CO2 disminuyó de 53,2±15,6 mmHg a 43,1±10mmHg, y la presión pico de la vía aérea se redujo de 16,8±5,9cm H2O a 16,6±5,3 cm de H2O, respectivamente. La ventilación con liberación de presión en la vía aérea, puede mejorar la oxigenación en pacientes pediátricos con insuficiencia respiratoria aguda, cuando la ventilación mecánica convencional falla.Airway pressure release ventilation is a mechanical ventilation method that uses a controlled positive airway pressure in order to maximize alveolar recruitment, with prolonged inspiratory times, therefore allowing spontaneous breathing during both phases of the respiratory cycle. The authors describe their experience in twelve cases of newborn patients with acute respiratory failure treated with airway pressure release ventilation when oxygenation did not improve with pressure control ventilation. The mean age of patients was 13 ± 16.5 days. The fractional concentration of oxygen (FiO2 decreased from 62.9 ± 23.6 cmH2O for pressure control ventilation to 44

  11. Airway management in trauma

    Directory of Open Access Journals (Sweden)

    Rashid M Khan

    2011-01-01

    Full Text Available Trauma has assumed epidemic proportion. 10% of global road accident deaths occur in India. Hypoxia and airway mismanagement are known to contribute up to 34% of pre-hospital deaths in these patients. A high degree of suspicion for actual or impending airway obstruction should be assumed in all trauma patients. Objective signs of airway compromise include agitation, obtundation, cyanosis, abnormal breath sound and deviated trachea. If time permits, one should carry out a brief airway assessment prior to undertaking definitive airway management in these patients. Simple techniques for establishing and maintaining airway patency include jaw thrust maneuver and/or use of oro- and nas-opharyngeal airways. All attempts must be made to perform definitive airway management whenever airway is compromised that is not amenable to simple strategies. The selection of airway device and route- oral or -nasal, for tracheal intubation should be based on nature of patient injury, experience and skill level.

  12. Continuous Positive Airway Pressure (CPAP)

    Science.gov (United States)

    ... heart disease, diabetes, and stroke. What Are the Disadvantages Of CPAP? The CPAP device needs to be ... able to advise you on the treatment options. Copyright © 2015 American Academy of Otolaryngology–Head and Neck ...

  13. Initial Treatment of Respiratory Distress Syndrome with Nasal Intermittent Mandatory Ventilation versus Nasal Continuous Positive Airway Pressure: A Randomized Controlled Trial

    Science.gov (United States)

    Armanian, Amir-Mohammad; Badiee, Zohreh; Heidari, Ghobad; Feizi, Awat; Salehimehr, Nima

    2014-01-01

    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 FIO2 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

  14. 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

  15. Effect of continuous positive airway pressure treatment on vascular endothelial function in patients with obstructive sleep apnea hypopnea syndrome and coronary artery disease

    Institute of Scientific and Technical Information of China (English)

    张希龙; 殷凯生; 毛辉; 王虹; 杨玉

    2004-01-01

    Background Continuous positive airway pressure (CPAP) treatment has been proven to be effective in improving the symptoms of coexisting coronary heart disease (CHD) in patients with obstructive sleep apnea hypopnea syndrome (OSAHS). However, it is still unclear whether such improvements are linked to changes in vascular endothelial function. This research was carried out to investigate the effects of CPAP treatment on vascular endothelial function in patients with OSAHS and CHD.Methods Thirty-six patients with moderate or severe OSAHS and CHD undergoing three months of CPAP treatment were recruited for this study. The changes in their morning plasma nitric oxide (NO) and endothelin (ET) levels, NO/ET ratio, total ischemic burden (TIB) of the myocardium, apnea hypopnea index (AHI), and minimal and mean pulse oxygen saturation (SpO2) were compared and analyzed before and during CPAP treatment. Results Compared with the plasma levels of ET [(51.39±11.69) ng/L] and NO [(36.67±11.86) μmol/L], NO/ET (0.71±0.14), AHI (32.4±7.9), minimal SpO2 [(68.9±11.4)%], and myocardial TIB [(66.29±16.37) mm*min] before treatment, there were significant decreases in ET [(33.41±10.03) ng/L] (P<0.05), increases in NO [(59.89±10.26) μmol/L] and NO/ET (1.79±0.38) (P<0.01), decreases in AHI (1.9±0.5), and increases in minimal SpO2 [(90.6±1.8) %] (all P<0.01) and myocardial TIB [(36.42±10.87) mm*min] (P<0.05) after three months of CPAP treatment.Conclusion CPAP treatment may play an important role in the improvement and protection of vascular endothelial dysfunction and myocardial ischemia in OSAHS patients with CHD.

  16. Effect of Continuous Positive Airway Pressure Therapy on Glycemic Excursions and Insulin Sensitivity in Patients with Obstructive Sleep Apnea-hypopnea Syndrome and Type 2 Diabetes

    Institute of Scientific and Technical Information of China (English)

    Li-Xin Guo; Xin Zhao; Qi Pan; Xue Sun; Hui Li; Xiao-Xia Wang; Li-Na Zhang

    2015-01-01

    Background:For patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) and type 2 diabetes mellitus (T2DM),the night sleep interruption and intermittent hypoxia due to apnea or hypopnea may induce glycemic excursions and reduce insulin sensitivity.This study aimed to investigate the effect of continuous positive airway pressure (CPAP) therapy in patients with OSAHS and T2DM.Methods:Continuous glucose monitoring system (CGMS) was used in 40 patients with T2DM and newly diagnosed OSAHS.The measurements were repeated after 30 days of CPAP treatment.Subsequently,insulin sensitivity and glycohemoglobin (HbA1c) were measured and compared to the pretreatment data.Results:After CPAP therapy,the CGMS indicators showed that the 24-h mean blood glucose (MBG) and the night time MBG were significantly reduced (P < 0.05 and P =0.03,respectively).The mean ambulatory glucose excursions (MAGEs) and the mean of daily differences were also significantly reduced (P < 0.05 and P =0.002,respectively) compared to pretreatment levels.During the night,MAGE also significantly decreased (P =0.049).The differences between the highest and lowest levels of blood glucose over 24 h and during the night were significantly lower than prior to CPAP treatment (P < 0.05 and P =0.024,respectively).The 24 h and night time durations of high blood glucose (>7.8 mmol/L and > 11.1 mmol/L) decreased (P < 0.05 and P < 0.05,respectively) after the treatment.Inaddition,HbA1c levels were also lower than those before treatment (P < 0.05),and the homeostasis model assessment index of insulin resistance was also significantly lower than before CPAP treatment (P =0.034).Conclusions:CPAP therapy may have a beneficial effect on improving not only blood glucose but also upon insulin sensitivity in T2DM patients with OSAHS.This suggests that CPAP may be an effective treatment for T2DM in addition to intensive diabetes management.

  17. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

    NARCIS (Netherlands)

    Wain, Louise V; Verwoert, Germaine C; O'Reilly, Paul F; Shi, Gang; Johnson, Toby; Johnson, Andrew D; Bochud, Murielle; Rice, Kenneth M; Henneman, Peter; Smith, Albert V; Ehret, Georg B; Amin, Najaf; Larson, Martin G; Mooser, Vincent; Hadley, David; Dörr, Marcus; Bis, Joshua C; Aspelund, Thor; Esko, Tõnu; Janssens, A Cecile J W; Zhao, Jing Hua; Heath, Simon; Laan, Maris; Fu, Jingyuan; Pistis, Giorgio; Luan, Jian'an; Arora, Pankaj; Lucas, Gavin; Pirastu, Nicola; Pichler, Irene; Jackson, Anne U; Webster, Rebecca J; Zhang, Feng; Peden, John F; Schmidt, Helena; Tanaka, Toshiko; Campbell, Harry; Igl, Wilmar; Milaneschi, Yuri; Hottenga, Jouke-Jan; Vitart, Veronique; Chasman, Daniel I; Trompet, Stella; Bragg-Gresham, Jennifer L; Alizadeh, Behrooz Z; Chambers, John C; Guo, Xiuqing; Lehtimäki, Terho; Kühnel, Brigitte; Lopez, Lorna M; Polašek, Ozren; Boban, Mladen; Nelson, Christopher P; Morrison, Alanna C; Pihur, Vasyl; Ganesh, Santhi K; Hofman, Albert; Kundu, Suman; Mattace-Raso, Francesco U S; Rivadeneira, Fernando; Sijbrands, Eric J G; Uitterlinden, Andre G; Hwang, Shih-Jen; Vasan, Ramachandran S; Wang, Thomas J; Bergmann, Sven; Vollenweider, Peter; Waeber, Gérard; Laitinen, Jaana; Pouta, Anneli; Zitting, Paavo; McArdle, Wendy L; Kroemer, Heyo K; Völker, Uwe; Völzke, Henry; Glazer, Nicole L; Taylor, Kent D; Harris, Tamara B; Alavere, Helene; Haller, Toomas; Keis, Aime; Tammesoo, Mari-Liis; Aulchenko, Yurii; Barroso, Inês; Khaw, Kay-Tee; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Eyheramendy, Susana; Org, Elin; Sõber, Siim; Lu, Xiaowen; Nolte, Ilja M; Penninx, Brenda W; Corre, Tanguy; Masciullo, Corrado; Sala, Cinzia; Groop, Leif; Voight, Benjamin F; Melander, Olle; O'Donnell, Christopher J; Salomaa, Veikko; d'Adamo, Adamo Pio; Fabretto, Antonella; Faletra, Flavio; Ulivi, Sheila; Del Greco, Fabiola M; Facheris, Maurizio; Collins, Francis S; Bergman, Richard N; Beilby, John P; Hung, Joseph; Musk, A William; Mangino, Massimo; Shin, So-Youn; Soranzo, Nicole; Watkins, Hugh; Goel, Anuj; Hamsten, Anders; Gider, Pierre; Loitfelder, Marisa; Zeginigg, Marion; Hernandez, Dena; Najjar, Samer S; Navarro, Pau; Wild, Sarah H; Corsi, Anna Maria; Singleton, Andrew; de Geus, Eco J C; Willemsen, Gonneke; Parker, Alex N; Rose, Lynda M; Buckley, Brendan; Stott, David; Orru, Marco; Uda, Manuela; van der Klauw, Melanie M; Zhang, Weihua; Li, Xinzhong; Scott, James; Chen, Yii-Der Ida; Burke, Gregory L; Kähönen, Mika; Viikari, Jorma; Döring, Angela; Meitinger, Thomas; Davies, Gail; Starr, John M; Emilsson, Valur; Plump, Andrew; Lindeman, Jan H; Hoen, Peter A C 't; König, Inke R; Felix, Janine F; Clarke, Robert; Hopewell, Jemma C; Ongen, Halit; Breteler, Monique; Debette, Stéphanie; Destefano, Anita L; Fornage, Myriam; Mitchell, Gary F; Smith, Nicholas L; Holm, Hilma; Stefansson, Kari; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Samani, Nilesh J; Preuss, Michael; Rudan, Igor; Hayward, Caroline; Deary, Ian J; Wichmann, H-Erich; Raitakari, Olli T; Palmas, Walter; Kooner, Jaspal S; Stolk, Ronald P; Jukema, J Wouter; Wright, Alan F; Boomsma, Dorret I; Bandinelli, Stefania; Gyllensten, Ulf B; Wilson, James F; Ferrucci, Luigi; Schmidt, Reinhold; Farrall, Martin; Spector, Tim D; Palmer, Lyle J; Tuomilehto, Jaakko; Pfeufer, Arne; Gasparini, Paolo; Siscovick, David; Altshuler, David; Loos, Ruth J F; Toniolo, Daniela; Snieder, Harold; Gieger, Christian; Meneton, Pierre; Wareham, Nicholas J; Oostra, Ben A; Metspalu, Andres; Launer, Lenore; Rettig, Rainer; Strachan, David P; Beckmann, Jacques S; Witteman, Jacqueline C M; Erdmann, Jeanette; van Dijk, Ko Willems; Boerwinkle, Eric; Boehnke, Michael; Ridker, Paul M; Jarvelin, Marjo-Riitta; Chakravarti, Aravinda; Abecasis, Goncalo R; Gudnason, Vilmundur; Newton-Cheh, Christopher; Levy, Daniel; Munroe, Patricia B; Psaty, Bruce M; Caulfield, Mark J; Rao, Dabeeru C; Tobin, Martin D; Elliott, Paul; van Duijn, Cornelia M

    2011-01-01

    Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we ident

  18. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

    NARCIS (Netherlands)

    Wain, Louise V.; Verwoert, Germaine C.; O'Reilly, Paul F.; Shi, Gang; Johnson, Toby; Johnson, Andrew D.; Bochud, Murielle; Rice, Kenneth M.; Henneman, Peter; Smith, Albert V.; Ehret, Georg B.; Amin, Najaf; Larson, Martin G.; Mooser, Vincent; Hadley, David; Doerr, Marcus; Bis, Joshua C.; Aspelund, Thor; Esko, Tonu; Janssens, A. Cecile J. W.; Zhao, Jing Hua; Heath, Simon; Laan, Maris; Fu, Jingyuan; Pistis, Giorgio; Luan, Jian'an; Arora, Pankaj; Lucas, Gavin; Pirastu, Nicola; Pichler, Irene; Jackson, Anne U.; Webster, Rebecca J.; Zhang, Feng; Peden, John F.; Schmidt, Helena; Tanaka, Toshiko; Campbell, Harry; Igl, Wilmar; Milaneschi, Yuri; Hottenga, Jouke-Jan; Vitart, Veronique; Chasman, Daniel I.; Trompet, Stella; Bragg-Gresham, Jennifer L.; Alizadeh, Behrooz Z.; Chambers, John C.; Guo, Xiuqing; Lehtimaki, Terho; Kuehnel, Brigitte; Lopez, Lorna M.; Polasek, Ozren; Boban, Mladen; Nelson, Christopher P.; Morrison, Alanna C.; Pihur, Vasyl; Ganesh, Santhi K.; Hofman, Albert; Kundu, Suman; Mattace-Raso, Francesco U. S.; Rivadeneira, Fernando; Sijbrands, Eric J. G.; Uitterlinden, Andre G.; Hwang, Shih-Jen; Vasan, Ramachandran S.; Wang, Thomas J.; Bergmann, Sven; Vollenweider, Peter; Waeber, Gerard; Laitinen, Jaana; Pouta, Anneli; Zitting, Paavo; McArdle, Wendy L.; Kroemer, Heyo K.; Voelker, Uwe; Voelzke, Henry; Glazer, Nicole L.; Taylor, Kent D.; Harris, Tamara B.; Alavere, Helene; Haller, Toomas; Keis, Aime; Tammesoo, Mari-Liis; Aulchenko, Yurii; Barroso, Ines; Khaw, Kay-Tee; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Eyheramendy, Susana; Org, Elin; Sober, Siim; Lu, Xiaowen; Nolte, Ilja M.; Penninx, Brenda W.; Corre, Tanguy; Masciullo, Corrado; Sala, Cinzia; Groop, Leif; Voight, Benjamin F.; Melander, Olle; O'Donnell, Christopher J.; Salomaa, Veikko; d'Adamo, Adamo Pio; Fabretto, Antonella; Faletra, Flavio; Ulivi, Sheila; Del Greco, Fabiola M.; Facheris, Maurizio; Collins, Francis S.; Bergman, Richard N.; Beilby, John P.; Hung, Joseph; Musk, A. William; Mangino, Massimo; Shin, So-Youn; Soranzo, Nicole; Watkins, Hugh; Goel, Anuj; Hamsten, Anders; Gider, Pierre; Loitfelder, Marisa; Zeginigg, Marion; Hernandez, Dena; Najjar, Samer S.; Navarro, Pau; Wild, Sarah H.; Corsi, Anna Maria; Singleton, Andrew; de Geus, Eco J. C.; Willemsen, Gonneke; Parker, Alex N.; Rose, Lynda M.; Buckley, Brendan; Stott, David; Orru, Marco; Uda, Manuela; van der Klauw, Melanie M.; Zhang, Weihua; Li, Xinzhong; Scott, James; Chen, Yii-Der Ida; Burke, Gregory L.; Kahonen, Mika; Viikari, Jorma; Doering, Angela; Meitinger, Thomas; Davies, Gail; Starr, John M.; Emilsson, Valur; Plump, Andrew; Lindeman, Jan H.; 't Hoen, Peter A. C.; Koenig, Inke R.; Felix, Janine F.; Clarke, Robert; Hopewell, Jemma C.; Ongen, Halit; Breteler, Monique; Debette, Stephanie; DeStefano, Anita L.; Fornage, Myriam; Mitchell, Gary F.; Smith, Nicholas L.; Holm, Hilma; Stefansson, Kari; Thorleifsson, Gudmar; Thorsteinsdottir, Unnur; Samani, Nilesh J.; Preuss, Michael; Rudan, Igor; Hayward, Caroline; Deary, Ian J.; Wichmann, H-Erich; Raitakari, Olli T.; Palmas, Walter; Kooner, Jaspal S.; Stolk, Ronald P.; Jukema, J. Wouter; Wright, Alan F.; Boomsma, Dorret I.; Bandinelli, Stefania; Gyllensten, Ulf B.; Wilson, James F.; Ferrucci, Luigi; Schmidt, Reinhold; Farrall, Martin; Spector, Tim D.; Palmer, Lyle J.; Tuomilehto, Jaakko; Pfeufer, Arne; Gasparini, Paolo; Siscovick, David; Altshuler, David; Loos, Ruth J. F.; Toniolo, Daniela; Snieder, Harold; Gieger, Christian; Meneton, Pierre; Wareham, Nicholas J.; Oostra, Ben A.; Metspalu, Andres; Launer, Lenore; Rettig, Rainer; Strachan, David P.; Beckmann, Jacques S.; Witteman, Jacqueline C. M.; Erdmann, Jeanette; van Dijk, Ko Willems; Boerwinkle, Eric; Boehnke, Michael; Ridker, Paul M.; Jarvelin, Marjo-Riitta; Chakravarti, Aravinda; Abecasis, Goncalo R.; Gudnason, Vilmundur; Newton-Cheh, Christopher; Levy, Daniel; Munroe, Patricia B.; Psaty, Bruce M.; Caulfield, Mark J.; Rao, Dabeeru C.; Tobin, Martin D.; Elliott, Paul; van Duijn, Cornelia M.

    2011-01-01

    Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans(1-3). We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we

  19. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

    NARCIS (Netherlands)

    L.V. Wain (Louise); G.C. Verwoert (Germaine); P.F. O'Reilly (Paul); G. Shi (Gang); T. Johnson (Toby); M. Bochud (Murielle); K. Rice (Kenneth); P. Henneman (Peter); A.V. Smith (Albert Vernon); G.B. Ehret (Georg); N. Amin (Najaf); M.G. Larson (Martin); V. Mooser (Vincent); D. Hadley (David); M. Dörr (Marcus); J.C. Bis (Joshua); T. Aspelund (Thor); T. Esko (Tõnu); A.C.J.W. Janssens (Cécile); J.H. Zhao; S.C. Heath (Simon); M. Laan (Maris); J. Fu (Jingyuan); G. Pistis (Giorgio); J. Luan; G. Lucas (Gavin); N. Pirastu (Nicola); I. Pichler (Irene); A.U. Jackson (Anne); R.J. Webster (Rebecca J.); F.F. Zhang; J. Peden (John); R. Schmidt (Reinhold); T. Tanaka (Toshiko); H. Campbell (Harry); W. Igl (Wilmar); Y. Milaneschi (Yuri); J.J. Hottenga (Jouke Jan); V. Vitart (Veronique); D.I. Chasman (Daniel); S. Trompet (Stella); J.L. Bragg-Gresham (Jennifer L.); B.Z. Alizadeh (Behrooz); J.C. Chambers (John); X. Guo (Xiuqing); T. Lehtimäki (Terho); B. Kuhnel (Brigitte); L.M. Lopez; O. Polasek (Ozren); M. Boban (Mladen); C.P. Nelson (Christopher P.); A.C. Morrison (Alanna); V. Pihur (Vasyl); S.K. Ganesh (Santhi); A. Hofman (Albert); S. Kundu (Suman); F.U.S. Mattace Raso (Francesco); F. Rivadeneira Ramirez (Fernando); E.J.G. Sijbrands (Eric); A.G. Uitterlinden (André); S.J. Hwang; R.S. Vasan (Ramachandran Srini); Y.A. Wang (Ying); S.M. Bergmann (Sven); P. Vollenweider (Peter); G. Waeber (Gérard); J. Laitinen (Jaana); A. Pouta (Anneli); P. Zitting (Paavo); W.L. McArdle (Wendy); H.K. Kroemer (Heyo); U. Völker (Uwe); H. Völzke (Henry); N.L. Glazer (Nicole); K.D. Taylor (Kent); T.B. Harris (Tamara); H. Alavere (Helene); T. Haller (Toomas); A. Keis (Aime); M.L. Tammesoo; Y.S. Aulchenko (Yurii); K-T. Khaw (Kay-Tee); P. Galan (Pilar); S. Hercberg (Serge); G.M. Lathrop (Mark); S. Eyheramendy (Susana); E. Org (Elin); S. Sõber (Siim); X. Lu (Xiaowen); I.M. Nolte (Ilja); B.W.J.H. Penninx (Brenda); T. Corre (Tanguy); C. Masciullo (Corrado); C. Sala (Cinzia); L. Groop (Leif); B.F. Voight (Benjamin); O. Melander (Olle); C.J. O'Donnell (Christopher); V. Salomaa (Veikko); P. d' Adamo (Pio); A. Fabretto (Antonella); F. Faletra (Flavio); S. Ulivi (Shelia); F. Del Greco M (Fabiola); M.F. Facheris (Maurizio); F.S. Collins (Francis); R.N. Bergman (Richard); J.P. Beilby (John); J. Hung (Judy); A.W. Musk (Arthur); M. Mangino (Massimo); S.Y. Shin (So Youn); N. Soranzo (Nicole); H. Watkins (Hugh); A. Goel (Anuj); A. Hamsten (Anders); P. Gider (Pierre); M. Loitfelder (Marisa); M. Zeginigg (Marion); D.G. Hernandez (Dena); S.S. Najjar (Samer); P. Navarro (Pau); S.H. Wild (Sarah); A.M. Corsi (Anna Maria); A. Singleton (Andrew); E.J.C. de Geus (Eco); G.A.H.M. Willemsen (Gonneke); A.N. Parker (Alex); L.M. Rose (Lynda); B.M. Buckley (Brendan M.); D.J. Stott (David. J.); M. Orrù (Marco); M. Uda (Manuela); M.M. van der Klauw (Melanie); X. Li (Xiaohui); J. Scott (James); Y.D.I. Chen (Yii-Der Ida); G.L. Burke (Greg); M. Kähönen (Mika); J. Viikari (Jorma); A. Döring (Angela); T. Meitinger (Thomas); G.S. Davis; J.M. Starr (John); V. Emilsson (Valur); A.S. Plump (Andrew); J.H. Lindeman (Jan H.); P.A.C. 't Hoen (Peter); I.R. König (Inke); J.F. Felix (Janine); R. Clarke; J. Hopewell; H. Ongen (Halit); M.M.B. Breteler (Monique); S. Debette (Stéphanie); A.L. DeStefano (Anita); M. Fornage (Myriam); G.F. Mitchell (Gary); H. Holm (Hilma); K. Stefansson (Kari); G. Thorleifsson (Gudmar); U. Thorsteinsdottir (Unnur); N.J. Samani (Nilesh); M. Preuss (Michael); I. Rudan (Igor); C. Hayward (Caroline); I.J. Deary (Ian); H.E. Wichmann (Heinz Erich); O. Raitakari (Olli); W. Palmas (Walter); J.S. Kooner (Jaspal); R.P. Stolk (Ronald); J.W. Jukema (Jan Wouter); A.F. Wright (Alan); D.I. Boomsma (Dorret); S. Bandinelli (Stefania); U. Gyllensten (Ulf); J.F. Wilson (James); L. Ferrucci (Luigi); M. Farrall (Martin); T.D. Spector (Timothy); L.J. Palmer; J. Tuomilehto (Jaakko); A. Pfeufer (Arne); P. Gasparini (Paolo); D.S. Siscovick (David); D. Altshuler (David); R.J.F. Loos (Ruth); D. Toniolo (Daniela); H. Snieder (Harold); C. Gieger (Christian); P. Meneton (Pierre); N.J. Wareham (Nick); B.A. Oostra (Ben); A. Metspalu (Andres); L.J. Launer (Lenore); R. Rettig (Rainer); D.P. Strachan (David); J.S. Beckmann (Jacques); J.C.M. Witteman (Jacqueline); J.A.P. Willems van Dijk (Ko); E.A. Boerwinkle (Eric); M. Boehnke (Michael); P.M. Ridker (Paul); M.R. Järvelin; A. Chakravarti (Aravinda); J. Erdmann (Jeanette); V. Gudnason (Vilmundur); C. Newton-Cheh (Christopher); D. Levy (Daniel); P. Arora (Pankaj); P. Munroe (Patricia); B.M. Psaty (Bruce); M. Caulfield (Mark); D.C. Rao (Dabeeru C.); P. Elliott (Paul); P. Tikka-Kleemola (Päivi); G.R. Abecasis (Gonçalo); I. Barroso (Inês)

    2011-01-01

    textabstractNumerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,60

  20. Influence of residual stresses on failure pressure of cylindrical pressure vessels

    Institute of Scientific and Technical Information of China (English)

    M. Jeyakumar; T. Christopher

    2013-01-01

    The utilization of pressure vessels in aerospace applications is manifold. In this work, finite element analysis (FEA) has been carried out using ANSYS software package with 2D axisym-metric model to access the failure pressure of cylindrical pressure vessel made of ASTM A36 carbon steel having weld-induced residual stresses. To find out the effect of residual stresses on failure pressure, first an elasto-plastic analysis is performed to find out the failure pressure of pressure vessel not having residual stresses. Then a thermo-mechanical finite element analysis is performed to assess the residual stresses developed in the pressure vessel during welding. Finally one more elasto-plastic analysis is performed to assess the effect of residual stresses on failure pressure of the pressure vessel having residual stresses. This analysis indicates reduction in the failure pressure due to unfavorable residual stresses.

  1. Pressure distension in leg vessels as influenced by prolonged bed rest and a pressure habituation regimen.

    Science.gov (United States)

    Eiken, Ola; Mekjavic, Igor B; Kounalakis, Stylianos N; Kölegård, Roger

    2016-06-15

    Bed rest increases pressure distension in arteries, arterioles, and veins of the leg. We hypothesized that bed-rest-induced deconditioning of leg vessels is governed by the removal of the local increments in transmural pressure induced by assuming erect posture and, therefore, can be counteracted by intermittently increasing local transmural pressure during the bed rest. Ten men underwent 5 wk of horizontal bed rest. A subatmospheric pressure (-90 mmHg) was intermittently applied to one lower leg [pressure habituation (PH) leg]. Vascular pressure distension was investigated before and after the bed rest, both in the PH and control (CN) leg by increasing local distending pressure, stepwise up to +200 mmHg. Vessel diameter and blood flow were measured in the posterior tibial artery and vessel diameter in the posterior tibial vein. In the CN leg, bed rest led to 5-fold and 2.7-fold increments (P pressure-distension and flow responses, respectively, and to a 2-fold increase in tibial vein pressure distension. In the PH leg, arterial pressure-distension and flow responses were unaffected by bed rest, whereas bed rest led to a 1.5-fold increase in venous pressure distension. It thus appears that bed-rest-induced deconditioning of leg arteries, arterioles, and veins is caused by removal of gravity-dependent local pressure loads and may be abolished or alleviated by a local pressure-habituation regimen.

  2. Do maternal and intrauterine factors influence blood pressure in childhood?

    OpenAIRE

    1992-01-01

    It has been proposed that maternal health and nutrition may be important in the development of adult cardiovascular risk, and that blood pressure may be an important intermediate step in this process. To examine the relevance of this hypothesis in contemporary British children, the relationships of several maternal factors to blood pressure were studied in 3360 children of European origin aged 5-7 years. Maternal age, height, and body mass index were all positively related to blood pressure i...

  3. Pressure Profiles in a Loop Heat Pipe under Gravity Influence

    Science.gov (United States)

    Ku, Jentung

    2015-01-01

    During the operation of a loop heat pipe (LHP), the viscous flow induces pressure drops in various elements of the loop. The total pressure drop is equal to the sum of pressure drops in vapor grooves, vapor line, condenser, liquid line and primary wick, and is sustained by menisci at liquid and vapor interfaces on the outer surface of the primary wick in the evaporator. The menisci will curve naturally so that the resulting capillary pressure matches the total pressure drop. In ground testing, an additional gravitational pressure head may be present and must be included in the total pressure drop when LHP components are placed in a non-planar configuration. Under gravity-neutral and anti-gravity conditions, the fluid circulation in the LHP is driven solely by the capillary force. With gravity assist, however, the flow circulation can be driven by the combination of capillary and gravitational forces, or by the gravitational force alone. For a gravity-assist LHP at a given elevation between the horizontal condenser and evaporator, there exists a threshold heat load below which the LHP operation is gravity driven and above which the LHP operation is capillary force and gravity co-driven. The gravitational pressure head can have profound effects on the LHP operation, and such effects depend on the elevation, evaporator heat load, and condenser sink temperature. This paper presents a theoretical study on LHP operations under gravity-neutral, anti-gravity, and gravity-assist modes using pressure diagrams to help understand the underlying physical processes. Effects of the condenser configuration on the gravitational pressure head and LHP operation are also discussed.

  4. Major influencing factors of water flooding in abnormally high-pressure carbonate reservoir

    Science.gov (United States)

    Qingying, Hou; Kaiyuan, Chen; Zifei, Fan; Libing, Fu; Yefei, Chen

    2017-01-01

    The higher pressure coefficient is the major characteristics of the abnormal high pressure carbonate reservoirs, which the pressure coefficient generally exceeds 1.2 and the initial formation pressure is higher than normal sandstone reservoirs. Due to the large pressure difference between initial formation and saturated pressure, oil wells are capable to production with high flow rate by the natural energy at early production stage. When the formation pressure drops to the saturation pressure, the water or gas is usually injected to stabilize the well productivity and sustain the formation pressure. Based on the characteristics of Kenkiak oilfield, a typical abnormal high pressure carbonate reservoir, a well group model is designed to simulate and analyze the influence factors on water flooding. The conclusion is that permeability, interlayer difference and reserve abundance are the main three factors on the water flooding development in these reservoirs.

  5. Influence of Casing Shoe Depth on Sustained Casing Pressure

    OpenAIRE

    2012-01-01

    In 2006 the Petroleum Safety Authority Norway (PSA) performed a well integrity survey. The survey indicated that about 20 % of wells on the Norwegian Continental shelf (NCS) may suffer from well integrity issues. Most of the problems were related to deficiency in annulus safety valve, tubing, cement and casing. Pressure build-up in annulus, i.e. sustained casing pressure, is one of the main indicators of a significant well integrity problem. Increased understanding on the field may help engin...

  6. Richtmyer-Meshkov unstable dynamics influenced by pressure fluctuations

    Science.gov (United States)

    Bhowmick, A. K.; Abarzhi, S. I.

    2016-11-01

    We theoretically study the effect of pressure fluctuations on the Richtmyer-Meshkov (RM) unstable interface in approximation of ideal incompressible immiscible fluids and two-dimensional flow. Pressure fluctuations are treated as an effective acceleration directed from the heavy to light fluid with inverse square time dependence. The group theory approach is applied to analyze large-scale coherent dynamics, solve the complete set of the governing equations, and find regular asymptotic solutions describing RM bubbles. A strong effect is found, for the first time to our knowledge, of pressure fluctuations on the interface morphology and dynamics. In the linear regime, a nearly flat bubble gets more curved, and its velocity increases for strong pressure fluctuations and decreases otherwise. In the nonlinear regime, solutions form a one-parameter family parameterized by the bubble front curvature. For the fastest stable solution in the family, the RM bubble is curved for strong pressure fluctuations and is flattened otherwise. The flow is characterized by the intense motion of the fluids in the vicinity of the interface, effectively no motion away from the interface, and presence of shear at the interface leading to formation of smaller scale vortical structures. Our theoretical results agree with and explain existing experiments and simulations and identify new qualitative and quantitative characteristics to evaluate the strength of pressure fluctuations in experiments and simulations.

  7. Pharmacology of airway afferent nerve activity

    Directory of Open Access Journals (Sweden)

    Carr Michael J

    2001-05-01

    Full Text Available Abstract Afferent nerves in the airways serve to regulate breathing pattern, cough, and airway autonomic neural tone. Pharmacologic agents that influence afferent nerve activity can be subclassified into compounds that modulate activity by indirect means (e.g. bronchial smooth muscle spasmogens and those that act directly on the nerves. Directly acting agents affect afferent nerve activity by interacting with various ion channels and receptors within the membrane of the afferent terminals. Whether by direct or indirect means, most compounds that enter the airspace will modify afferent nerve activity, and through this action alter airway physiology.

  8. Influence of ambient air pressure on impact pressure caused by breaking waves

    NARCIS (Netherlands)

    Moutzouris, C.

    1979-01-01

    Engineers are interested in the dynamics of the interface waterstructure. In case of breaking of water waves on a structure high positive and sometimes negative pressures of very short duration occur. Not only the maxima and minima of the pressures on the structure are important to a designing engin

  9. Compression Garments and Exercise: No Influence of Pressure Applied

    Science.gov (United States)

    Beliard, Samuel; Chauveau, Michel; Moscatiello, Timothée; Cros, François; Ecarnot, Fiona; Becker, François

    2015-01-01

    Compression garments on the lower limbs are increasingly popular among athletes who wish to improve performance, reduce exercise-induced discomfort, and reduce the risk of injury. However, the beneficial effects of compression garments have not been clearly established. We performed a review of the literature for prospective, randomized, controlled studies, using quantified lower limb compression in order to (1) describe the beneficial effects that have been identified with compression garments, and in which conditions; and (2) investigate whether there is a relation between the pressure applied and the reported effects. The pressure delivered were measured either in laboratory conditions on garments identical to those used in the studies, or derived from publication data. Twenty three original articles were selected for inclusion in this review. The effects of wearing compression garments during exercise are controversial, as most studies failed to demonstrate a beneficial effect on immediate or performance recovery, or on delayed onset of muscle soreness. There was a trend towards a beneficial effect of compression garments worn during recovery, with performance recovery found to be improved in the five studies in which this was investigated, and delayed-onset muscle soreness was reportedly reduced in three of these five studies. There is no apparent relation between the effects of compression garments worn during or after exercise and the pressures applied, since beneficial effects were obtained with both low and high pressures. Wearing compression garments during recovery from exercise seems to be beneficial for performance recovery and delayed-onset muscle soreness, but the factors explaining this efficacy remain to be elucidated. Key points We observed no relationship between the effects of compression and the pressures applied. The pressure applied at the level of the lower limb by compression garments destined for use by athletes varies widely between

  10. Influence of effective stress on swelling pressure of expansive soils

    Directory of Open Access Journals (Sweden)

    Baille Wiebke

    2016-01-01

    Full Text Available The volume change and shear strength behaviour of soils are controlled by the effective stress. Recent advances in unsaturated soil mechanics have shown that the effective stress as applicable to unsaturated soils is equal to the difference between the externally applied stress and the suction stress. The latter can be established based on the soil-water characteristic curve (SWCC of the soil. In the present study, the evolution of swelling pressure in compacted bentonite-sand mixtures was investigated. Comparisons were made between magnitudes of applied suction, suction stress, and swelling pressure.

  11. The laryngeal mask airway at altitude.

    Science.gov (United States)

    Wilson, Grant D; Sittig, Steven E; Schears, Gregory J

    2008-02-01

    The Laryngeal Mask Airway (LMA) is an accepted adjunct for airway management in emergency patients. There are a number of case reports describing its use in transport medicine for infant to adult patients, including during flight. Although studies of the effect altitude has on air-filled tracheal tubes exists, we were unable to find documentation of the effect of altitude on laryngeal mask airways. Our objective was to assess the effect of altitude on the LMA in both fixed wing and rotary wing models. We performed an in vitro study of the effect of altitude on the LMA cuff. Infant and adult airway trainer mannequins with properly sized and inserted LMA-Classic laryngeal mask airways were monitored for cuff pressure changes while flown at altitudes commonly encountered during air medical transport. Both models demonstrated that LMA cuff pressures may exceed manufacturer recommended levels for safe use even at the relatively low altitudes experienced during rotor wing flight. Properly inserted and inflated laryngeal mask airways at ground level may result in overinflated LMA cuffs when flown to altitudes commonly used for rotor and fixed wing medical transport unless monitored and corrected.

  12. Influence of caffeine on blood pressure and platelet aggregation

    Directory of Open Access Journals (Sweden)

    José Wilson S. Cavalcante

    2000-08-01

    Full Text Available OBJECTIVE: Studies have demonstrated that methylxanthines, such as caffeine, are A1 and A2 adenosine receptor antagonists found in the brain, heart, lungs, peripheral vessels, and platelets. Considering the high consumption of products with caffeine in their composition, in Brazil and throughout the rest of the world, the authors proposed to observe the effects of this substance on blood pressure and platelet aggregation. METHODS: Thirteen young adults, ranging from 21 to 27 years of age, participated in this study. Each individual took 750mg/day of caffeine (250mg tid, over a period of seven days. The effects on blood pressure were analyzed through the pressor test with handgrip, and platelet aggregation was analyzed using adenosine diphosphate, collagen, and adrenaline. RESULTS: Diastolic pressure showed a significant increase 24 hours after the first intake (p<0.05. This effect, however, disappeared in the subsequent days. The platelet aggregation tests did not reveal statistically significant alterations, at any time during the study. CONCLUSION: The data suggest that caffeine increases diastolic blood pressure at the beginning of caffeine intake. This hypertensive effect disappears with chronic use. The absence of alterations in platelet aggregation indicates the need for larger randomized studies.

  13. Influence of high injection pressure on fuel injection perfomances and diesel engine worcking process

    Directory of Open Access Journals (Sweden)

    Shatrov Mikhail G.

    2015-01-01

    Full Text Available In MADI, investigations are carried out in the field of diesel engine working process perfection for complying with prospective ecological standards such as Euro-6 and Tier-4. The article describes the results of the first stage of experimental research of the influence of injection pressure up to 3000 bar on working processes of diesel engine and its fuel system. Justification of the design of a Common Rail injector for fuel injection under 3000 bar pressure is presented. The influence of raising injection pressure (up to 3000 bar on the fuel spray propagation dynamics is demonstrated. The combined influence of injection pressure (up to 3000 bar and air boost pressure on fuel spray propagation dynamics is shown, including on engine emission and noise.

  14. The influence of low-permeability cap on capillary pressure during pumping in unconfined aquifer

    Institute of Scientific and Technical Information of China (English)

    黄辉; 钱家忠; 匡星星; 陈冰宇; 马雷; 吴亚楠

    2013-01-01

    The pumping test in an unconfined aquifer with and without a low-permeability soil was studied experimentally to reveal the influence of the negative air pressure (NP) caused by the upper layer on the water content(w), the water pressure(Pw), as well as on the capillary pressure(Pc). The study demonstrates that the NP generated in the vadose zone during pumping in the capper aquifer has a significant influence onw,wP andPc. ThecP obtained from the capped aquifer is smaller than that without the upper layer. After the NP reaches a peak, the influence of the NP onPc is gradually declined as the air inflows through the upper layer which makes the NP gradually return to zero. When the air pressure returns to the atmospheric pressure,Pc in the vadose zone is only correlated withPw, the same as the case with no upper layer.

  15. Insulin as a potential factor influencing blood pressure in amputees.

    Science.gov (United States)

    Rose, H G; Yalow, R S; Schweitzer, P; Schwartz, E

    1986-09-01

    War-injured, bilateral above-knee amputees are known to be at increased risk for cardiovascular mortality. To evaluate possible risk factors, we compared blood pressures and plasma glucose and insulin responses to orally administered glucose in 19 above-knee amputees from the Vietnam War (mean age, 36 +/- 1 years) with those of 12 age-matched unilateral below-elbow amputees. Body composition by densitometry and maximal oxygen consumption during arm or leg exercise were also determined. Nine of 19 leg amputees were hypertensive compared with one of 12 arm amputees. Their 3-hour average insulin responses were markedly increased (260 +/- 60 microU/ml) compared with those of normotensive leg (125 +/- 24 microU/ml) and arm amputees (101 +/- 20 microU/ml), and their mean body fat content (37.2%) also was elevated compared with that in both of these groups (23.2 and 22.6%, respectively). A unique finding was that both insulin response and body fat content were strongly and independently correlated with diastolic blood pressure (r = 0.55, p less than 0.01, and r = 0.62, p less than 0.01, respectively). We conclude that insulin may be a major factor in blood pressure regulation in the maturity-onset obesity that develops following traumatic leg amputation in young, healthy men.

  16. The Influence of Unidirectional Pressure on Electrical Conductivity of Carbon Black Filled Polyethylene

    Institute of Scientific and Technical Information of China (English)

    WANG Ke; ZHANG Guo; ZHAO Zhudi; PENG Yi; DI Weihua; DU Chuang

    2006-01-01

    High density polyethylene filled with conductive carbon black was prepared by conventional melt-mixing method. The effect of unidirectional pressure on the conductivity was studied. Wide angle X-ray diffraction (WAXD) was used to show the influence of pressure on the aggregate structure of the polymer filled with carbon black (CB) fillers. A model on the basis of the formation and destruction of conductive networks was proposed to explain the change in the conductivity with the application of pressure.

  17. Evaluation of short-term use of nocturnal nasal continuous positive airway pressure for a clinical profile and exercise capacity in adult patients with obstructive sleep apnea-hypopnea syndrome

    Directory of Open Access Journals (Sweden)

    Amrit K Goel

    2015-01-01

    Full Text Available Background and Aim: The obstructive sleep apnea-hypopnea syndrome (OSAHS is a common chronic respiratory disease, characterized by repetitive complete or partial collapse of the upper airway during sleep. The clinical spectrum extends between stoppage of breathing, snoring, daytime somnolence, and fatigue, to serious cardiovascular disease, stroke, metabolic syndrome, increased morbidity, and mortality. We aim to evaluate the short-term use of nasal continuous positive airway pressure (nCPAP therapy for the clinical profile and exercise capacity of patients with OSAHS. Patient Selection: Twenty patients diagnosed with moderate-to-severe OSAHS were enrolled in the study (study group - 15; clinically and PSG-matched control group - 5. Materials and Methods: Each patient was clinically evaluated for sleep-related symptoms, and also assessed with spirometry, the six-minute walk test (6MWT, and a symptom-limited incremental cardiopulmonary exercise test (CPET. The study group patients were administered nCPAP therapy for eight hours each night for four weeks, while the control group patients were just observed. They were re-assessed after four weeks and the data were statistically analyzed between the two groups. Results: The study group patients showed a significant (P- < 0.05 improvement in the OSAHS symptoms-the Epworth sleepiness score, six-minute walk distance; duration of exercise, power output, peak oxygen uptake, anaerobic threshold, diastolic blood pressure, dyspnea, and fatigue-in comparison with the control group patients. The improvement in exercise capacity following nCPAP therapy was attributed to the relief of disabling the OSAHS symptoms and improved cardiovascular, ventilator, and musculoskeletal functions. Conclusion: All OSAHS patients must be treated with nCPAP.

  18. Engineering Airway Epithelium

    Directory of Open Access Journals (Sweden)

    John P. Soleas

    2012-01-01

    Full Text Available Airway epithelium is constantly presented with injurious signals, yet under healthy circumstances, the epithelium maintains its innate immune barrier and mucociliary elevator function. This suggests that airway epithelium has regenerative potential (I. R. Telford and C. F. Bridgman, 1990. In practice, however, airway regeneration is problematic because of slow turnover and dedifferentiation of epithelium thereby hindering regeneration and increasing time necessary for full maturation and function. Based on the anatomy and biology of the airway epithelium, a variety of tissue engineering tools available could be utilized to overcome the barriers currently seen in airway epithelial generation. This paper describes the structure, function, and repair mechanisms in native epithelium and highlights specific and manipulatable tissue engineering signals that could be of great use in the creation of artificial airway epithelium.

  19. Influence of geomagnetic activity and atmospheric pressure on human arterial pressure during the solar cycle 24

    Science.gov (United States)

    Azcárate, T.; Mendoza, B.; Levi, J. R.

    2016-11-01

    We performed a study of the systolic (SBP) and diastolic (DBP) arterial blood pressure behavior under natural variables such as the atmospheric pressure (AtmP) and the horizontal geomagnetic field component (H). We worked with a sample of 304 healthy normotense volunteers, 152 men and 152 women, with ages between 18 and 84 years in Mexico City during the period 2008-2014, corresponding to the minimum, ascending and maximum phases of the solar cycle 24. The data was divided by gender, age and day/night cycle. We studied the time series using three methods: Correlations, bivariate and superposed epochs (within a window of three days around the day of occurrence of a geomagnetic storm) analysis, between the SBP and DBP and the natural variables (AtmP and H). The correlation analysis indicated correlation between the SBP and DBP and AtmP and H, being the largest during the night. Furthermore, the correlation and bivariate analysis showed that the largest correlations are between the SBP and DBP and the AtmP. The superposed epoch analysis found that the largest number of significant SBP and DBP changes occurred for women. Finally, the blood pressure changes are larger during the solar minimum and ascending solar cycle phases than during the solar maximum; the storms of the minimum were more intense than those of the maximum and this could be the reason of behavior of the blood pressure changes along the solar cycle.

  20. Novel method for conscious airway resistance and ventilation estimation in neonatal rodents using plethysmography and a mechanical lung.

    Science.gov (United States)

    Zhang, Boyang; McDonald, Fiona B; Cummings, Kevin J; Frappell, Peter B; Wilson, Richard J A

    2014-09-15

    In unrestrained whole body plethysmography, tidal volume is commonly determined using the barometric method, which assumes that temperature and humidity changes (the 'barometric component') are solely responsible for breathing-related chamber pressure fluctuations. However, in small animals chamber pressure is also influenced by a 'mechanical component' dependent on airway resistance and airflow. We devised a novel 'mechanical lung' capable of simulating neonatal mouse breathing in the absence of temperature or humidity changes. Using this device, we confirm that the chamber pressure fluctuations produced by breathing of neonatal mice are dominated by the mechanical component, precluding direct quantitative assessment of tidal volume. Recognizing the importance of airway resistance to the chamber pressure signal and the ability of our device to simulate neonatal breathing at different frequencies and tidal volumes, we invented a novel in vivo, non-invasive method for conscious airway resistance and ventilation estimation (CARVE) in neonatal rodents. This technique will allow evaluation of developmental, pathological and pharmaceutical effects on airway resistance.

  1. Influence of tip clearance on pressure fluctuations in an axial flow pump

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Jianjun; Luo, Xingqi; Guo, Pengcheng; Wu, Guangkuan [Xi' an University, Xi' an (China)

    2016-04-15

    Rotor-stator interaction in axial pumps can produce pressure fluctuations and further vibrations even damage to the pump system in some extreme case. In this paper, the influence of tip clearance on pressure fluctuations in an axial flow water pump has been investigated by numerical method. Three-dimensional unsteady flow in the axial flow water pump has been simulated with different tip clearances between the impeller blade tip and the casing wall. In addition to monitoring pressure fluctuations at some typical points, a new method based on pressure statistics was proposed to determine pressure fluctuations at all grid nodes inside the whole pump. The comparison shows that the existence of impeller tip clearance magnifies the pressure fluctuations in the impeller region, from the hub to shroud. However, the effect on pressure fluctuation in the diffuser region is not evident. Furthermore, the tip clearance vortex has also been examined under different tip clearances.

  2. Impact of airway morphological changes on pulmonary flows in scoliosis

    Science.gov (United States)

    Farrell, James; Garrido, Enrique; Valluri, Prashant

    2016-11-01

    The relationship between thoracic deformity in scoliosis and lung function is poorly understood. In a pilot study, we reviewed computed tomography (CT) routine scans of patients undergoing scoliosis surgery. The CT scans were processed to segment the anatomy of the airways, lung and spine. A three-dimensional model was created to study the anatomical relationship. Preliminary analysis showed significant airway morphological differences depending on the anterior position of the spine. A computational fluid dynamics (CFD) study was also conducted on the airway geometry using the inspiratory scans. The CFD model assuming non-compliant airway walls was capable of showing pressure drops in areas of high airway resistance, but was unable to predict regional ventilation differences. Our results indicate a dependence between the dynamic deformation of the airway during breathing and lung function. Dynamic structural deformation must therefore be incorporated within any modelling approaches to guide clinicians on the decision to perform surgical correction of the scoliosis.

  3. Influence of heat transfer rates on pressurization of liquid/slush hydrogen propellant tanks

    Science.gov (United States)

    Sasmal, G. P.; Hochstein, J. I.; Hardy, T. L.

    1993-01-01

    A multi-dimensional computational model of the pressurization process in liquid/slush hydrogen tank is developed and used to study the influence of heat flux rates at the ullage boundaries on the process. The new model computes these rates and performs an energy balance for the tank wall whereas previous multi-dimensional models required a priori specification of the boundary heat flux rates. Analyses of both liquid hydrogen and slush hydrogen pressurization were performed to expose differences between the two processes. Graphical displays are presented to establish the dependence of pressurization time, pressurant mass required, and other parameters of interest on ullage boundary heat flux rates and pressurant mass flow rate. Detailed velocity fields and temperature distributions are presented for selected cases to further illuminate the details of the pressurization process. It is demonstrated that ullage boundary heat flux rates do significantly effect the pressurization process and that minimizing heat loss from the ullage and maximizing pressurant flow rate minimizes the mass of pressurant gas required to pressurize the tank. It is further demonstrated that proper dimensionless scaling of pressure and time permit all the pressure histories examined during this study to be displayed as a single curve.

  4. Airway management in trauma

    Directory of Open Access Journals (Sweden)

    Rao B

    2004-01-01

    Full Text Available Airway Management for the victims of major trauma is the first priority in the care of the trauma victim and is a core skill in emergency medicine and critical care. Endotracheal intubation remains the gold standard for trauma airway management. Airway management in trauma patients is not just the capability to insert an oral/nasal airway or endotracheal tube beyond the vocal cords. The five components integral to modern, sophisticated airway management in trauma patients include equipment, pharmacologic adjuncts, manual techniques, physical circumstances, and patient profile. A trauma patient may require airway management in a variety of physical circumstances. Whereas, the commonly used airway management algorithms may not suffice in all these situations, the construction of a truly complete decision tree is also virtually impossible. There is consensus that it is not the intervention per se but rather the conditions, skills, and performance that might be the possible variables that affect outcome. Paramedics have only limited experience and on-the-job skills for invasive airway management. Difficult airway management is best left for the experienced physicians to handle.

  5. Randomized crossover comparison of the laryngeal mask airway classic with i-gel laryngeal mask airway in the management of difficult airway in post burn neck contracture patients

    Directory of Open Access Journals (Sweden)

    Jeevan Singh

    2012-01-01

    Full Text Available Purpose: The objective of the study was to compare the performance of i-gel supraglottic airway with cLMA in difficult airway management in post burn neck contracture patients and assess the feasibility of i-gel use for emergency airway management in difficult airway situation with reduced neck movement and limited mouth opening. Methods: Prospective, crossover, randomized controlled trial was performed amongst forty eight post burn neck contracture patients with limited mouth opening and neck movement. i-gel and cLMA were placed in random order in each patient. Primary outcome was overall success rate. Other measurements were time to successful ventilation, airway leak pressure, fiberoptic glottic view, visualization of square wave pattern. Results: Success rate for the i-gel was 91.7% versus 79.2% for the cLMA. i-gel required shorter insertion time (19.3 seconds vs. 23.5 seconds, P=0.000. Airway leak pressure difference was statistically significant (i-gel 21.2 cm H20; cLMA 16.9 cm H 2 0; P=0.00. Fiberoptic view through the i-gel showed there were less epiglottic downfolding and better fiberoptic view of the glottis than cLMA. Overall agreement in insertion outcome for i-gel was 22/24 (91.7% successes and 2/24(8.3% failure and for cLMA, 19/24 (79.16% successes and 5/24 (16.7% failure in the first attempt. Conclusion: The i-gel is cheap, effective airway device which is easier to insert and has better clinical performance in the difficult airway management of the airway in the post burn contracture of the neck. Our study shows that i-gel is feasible for emergency airway management in difficult airway situation with reduced neck movement and limited mouth opening in post burn neck.

  6. Influence of aerobic exercise training on post-exercise responses of aortic pulse pressure and augmentation pressure in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Nobuhiko eAkazawa

    2015-10-01

    Full Text Available Central arterial blood pressure (BP is more predictive of future cardiovascular events than is brachial BP because it reflects the BP load imposed on the left ventricle with greater accuracy. However, little is known about the effects of exercise training on central hemodynamic response to acute exercise. The purpose of the present study was to determine the influence of an aerobic exercise regimen on the response of aortic BP after a single aerobic exercise in postmenopausal women. Nine healthy postmenopausal women (age: 61 ± 2 years participated in a 12-week aerobic exercise training regimen. Before and after the training, each subjects performed a single bout of cycling at ventilatory thresholds for 30 min. We evaluated the post-exercise aortic BP response, which was estimated via the general transfer function from applanation tonometry. After the initial pre-training aerobic exercise session, aortic BP did not change significantly: however, aortic pulse pressure and augmentation pressure were significantly attenuated after the single aerobic exercise session following the 12-week training regimen. The present study demonstrated that a regular aerobic exercise training regimen induced the post-exercise reduction of aortic pulse pressure and augmentation pressure. Regular aerobic exercise training may enhance post-exercise reduction in aortic BP.

  7. Elective use of the Ventrain for upper airway obstruction during high-frequency jet ventilation.

    Science.gov (United States)

    Fearnley, Robert A; Badiger, Sheela; Oakley, Richard J; Ahmad, Imran

    2016-09-01

    The safety of high pressure source ventilation (jet ventilation) is dependent upon upper airway patency to facilitate adequate passive expiration and prevent increasing intrathoracic pressure and its associated deleterious sequelae. Distortions in airway anatomy may make passive expiration inadequate or impossible in some patients. We report the elective use of the Ventrain device to provide ventilation in a clinical setting of upper airway obstruction in a patient with post radiation fibrosis that had previously prevented passive expiration during attempted high pressure source ventilation.

  8. Influence of airway management strategy on "no-flow-time" during an "Advanced life support course" for intensive care nurses – A single rescuer resuscitation manikin study

    Directory of Open Access Journals (Sweden)

    Bahr Jan

    2008-04-01

    Full Text Available Abstract Background In 1999, the laryngeal tube (VBM Medizintechnik, Sulz, Germany was introduced as a new supraglottic airway. It was designed to allow either spontaneous breathing or controlled ventilation during anaesthesia; additionally it may serve as an alternative to endotracheal intubation, or bag-mask ventilation during resuscitation. Several variations of this supraglottic airway exist. In our study, we compared ventilation with the laryngeal tube suction for single use (LTS-D and a bag-mask device. One of the main points of the revised ERC 2005 guidelines is a low no-flow-time (NFT. The NFT is defined as the time during which no chest compression occurs. Traditionally during the first few minutes of resuscitation NFT is very high. We evaluated the hypothesis that utilization of the LTS-D could reduce the NFT compared to bag-mask ventilation (BMV during simulated cardiac arrest in a single rescuer manikin study. Methods Participants were studied during a one day advanced life support (ALS course. Two scenarios of arrhythmias requiring defibrillation were simulated in a manikin. One scenario required subjects to establish the airway with a LTS-D; alternatively, the second scenario required them to use BMV. The scenario duration was 430 seconds for the LTS-D scenario, and 420 seconds for the BMV scenario, respectively. Experienced ICU nurses were recruited as study subjects. Participants were randomly assigned to one of the two groups first (LTS-D and BMV to establish the airway. Endpoints were the total NFT during the scenario, the successful airway management using the respective device, and participants' preference of one of the two strategies for airway management. Results Utilization of the LTS-D reduced NFT significantly (p Conclusion In our manikin study, NFT was reduced significantly when using LTS-D compared to BMV. During cardiac arrest, the LTS-D might be a good alternative to BMV for providing and maintaining a patent airway

  9. Influence of Pressure on Stable Film Boiling of Subcooled Liquid

    Science.gov (United States)

    Zabirov, A. R.; Yagov, V. V.; Kaban'kov, O. N.; Leksin, M. A.; Kanin, P. K.

    2016-11-01

    Film boiling of subcooled liquids is an integral part of the hardening process. Understanding of the mechanisms underlying film boiling is important for modeling processes in atomic power engineering and cryogenic technology. Stationary processes of film boiling of subcooled liquids under conditions of their free motion near cylindrical heaters, just as subcooled liquid turbulent flow past high-temperature surfaces, represent quite a different type of process. In cooling metal spheres heated to a high temperature by a subcooled water, a special regime of film boiling is observed (microbubble boiling) distinguished by high intensity of heat transfer. Such a regime has not been revealed up to now for nonaqueous liquids. The paper presents new experimental data on heat transfer regimes in cooling nickel spheres in subcooled isopropanol and perfluorohexane at pressures of up to 1 MPa. It has been established that stable film boiling is the main regime of heat transfer that accounts for the larger part of the total time of cooling. The regimes of highly intensive film boiling heat transfer were not observed in the entire range of operational parameters even in the case of extreme subcoolings of liquid below their saturation temperature (to 170 K). The intensity of heat transfer in stable film boiling increases noticeably with subcooling of a chilling liquid.

  10. Indirect airway challenges

    NARCIS (Netherlands)

    Joos, GF; O'Connor, B; Anderson, SD; Chung, F; Cockcroft, DW; Dahlen, B; DiMaria, G; Foresi, A; Hargreave, FE; Holgate, ST; Inman, M; Lotvall, J; Magnussen, H; Polosa, R; Postma, DS; Riedler, J

    2003-01-01

    Indirect challenges act by causing the release of endogenous mediators that cause the airway smooth muscle to contract. This is in contrast to the direct challenges where agonists such as methacholine or histamine cause airflow limitation predominantly via a direct effect on airway smooth muscle. Di

  11. Pediatric airway nightmares.

    Science.gov (United States)

    D'Agostino, James

    2010-02-01

    Pediatric disorders that involve actual or potential airway compromise are among the most challenging cases that emergency department providers face. This article discusses the diagnosis and management of common and uncommon conditions in infants and children who may present with airway obstruction.

  12. Genes influencing circadian differences in blood pressure in hypertensive mice.

    Directory of Open Access Journals (Sweden)

    Francine Z Marques

    Full Text Available Essential hypertension is a common multifactorial heritable condition in which increased sympathetic outflow from the central nervous system is involved in the elevation in blood pressure (BP, as well as the exaggerated morning surge in BP that is a risk factor for myocardial infarction and stroke in hypertensive patients. The Schlager BPH/2J mouse is a genetic model of hypertension in which increased sympathetic outflow from the hypothalamus has an important etiological role in the elevation of BP. Schlager hypertensive mice exhibit a large variation in BP between the active and inactive periods of the day, and also show a morning surge in BP. To investigate the genes responsible for the circadian variation in BP in hypertension, hypothalamic tissue was collected from BPH/2J and normotensive BPN/3J mice at the 'peak' (n = 12 and 'trough' (n = 6 of diurnal BP. Using Affymetrix GeneChip® Mouse Gene 1.0 ST Arrays, validation by quantitative real-time PCR and a statistical method that adjusted for clock genes, we identified 212 hypothalamic genes whose expression differed between 'peak' and 'trough' BP in the hypertensive strain. These included genes with known roles in BP regulation, such as vasopressin, oxytocin and thyrotropin releasing hormone, as well as genes not recognized previously as regulators of BP, including chemokine (C-C motif ligand 19, hypocretin and zinc finger and BTB domain containing 16. Gene ontology analysis showed an enrichment of terms for inflammatory response, mitochondrial proton-transporting ATP synthase complex, structural constituent of ribosome, amongst others. In conclusion, we have identified genes whose expression differs between the peak and trough of 24-hour circadian BP in BPH/2J mice, pointing to mechanisms responsible for diurnal variation in BP. The findings may assist in the elucidation of the mechanism for the morning surge in BP in essential hypertension.

  13. Genes influencing circadian differences in blood pressure in hypertensive mice.

    Science.gov (United States)

    Marques, Francine Z; Campain, Anna E; Davern, Pamela J; Yang, Yee Hwa J; Head, Geoffrey A; Morris, Brian J

    2011-04-26

    Essential hypertension is a common multifactorial heritable condition in which increased sympathetic outflow from the central nervous system is involved in the elevation in blood pressure (BP), as well as the exaggerated morning surge in BP that is a risk factor for myocardial infarction and stroke in hypertensive patients. The Schlager BPH/2J mouse is a genetic model of hypertension in which increased sympathetic outflow from the hypothalamus has an important etiological role in the elevation of BP. Schlager hypertensive mice exhibit a large variation in BP between the active and inactive periods of the day, and also show a morning surge in BP. To investigate the genes responsible for the circadian variation in BP in hypertension, hypothalamic tissue was collected from BPH/2J and normotensive BPN/3J mice at the 'peak' (n = 12) and 'trough' (n = 6) of diurnal BP. Using Affymetrix GeneChip® Mouse Gene 1.0 ST Arrays, validation by quantitative real-time PCR and a statistical method that adjusted for clock genes, we identified 212 hypothalamic genes whose expression differed between 'peak' and 'trough' BP in the hypertensive strain. These included genes with known roles in BP regulation, such as vasopressin, oxytocin and thyrotropin releasing hormone, as well as genes not recognized previously as regulators of BP, including chemokine (C-C motif) ligand 19, hypocretin and zinc finger and BTB domain containing 16. Gene ontology analysis showed an enrichment of terms for inflammatory response, mitochondrial proton-transporting ATP synthase complex, structural constituent of ribosome, amongst others. In conclusion, we have identified genes whose expression differs between the peak and trough of 24-hour circadian BP in BPH/2J mice, pointing to mechanisms responsible for diurnal variation in BP. The findings may assist in the elucidation of the mechanism for the morning surge in BP in essential hypertension.

  14. Influence of air pressure on the performance of plasma synthetic jet actuator

    Science.gov (United States)

    Li, Yang; Jia, Min; Wu, Yun; Li, Ying-hong; Zong, Hao-hua; Song, Hui-min; Liang, Hua

    2016-09-01

    Plasma synthetic jet actuator (PSJA) has a wide application prospect in the high-speed flow control field for its high jet velocity. In this paper, the influence of the air pressure on the performance of a two-electrode PSJA is investigated by the schlieren method in a large range from 7 kPa to 100 kPa. The energy consumed by the PSJA is roughly the same for all the pressure levels. Traces of the precursor shock wave velocity and the jet front velocity vary a lot for different pressures. The precursor shock wave velocity first decreases gradually and then remains at 345 m/s as the air pressure increases. The peak jet front velocity always appears at the first appearance of a jet, and it decreases gradually with the increase of the air pressure. A maximum precursor shock wave velocity of 520 m/s and a maximum jet front velocity of 440 m/s are observed at the pressure of 7 kPa. The averaged jet velocity in one period ranges from 44 m/s to 54 m/s for all air pressures, and it drops with the rising of the air pressure. High velocities of the precursor shock wave and the jet front indicate that this type of PSJA can still be used to influence the high-speed flow field at 7 kPa. Project supported by the National Natural Science Foundation of China (Grant Nos. 51407197, 51522606, 51336011, 91541120, and 11472306).

  15. Upper airway resistance syndrome.

    Science.gov (United States)

    Montserrat, J M; Badia, J R

    1999-03-01

    This article reviews the clinical picture, diagnosis and management of the upper airway resistance syndrome (UARS). Presently, there is not enough data on key points like the frequency of UARS and the morbidity associated with this condition. Furthermore, the existence of LIARS as an independent sleep disorder and its relation with snoring and obstructive events is in debate. The diagnosis of UARS is still a controversial issue. The technical limitations of the classic approach to monitor airflow with thermistors and inductance plethysmography, as well as the lack of a precise definition of hypopnea, may have led to a misinterpretation of UARS as an independent diagnosis from the sleep apnea/hypopnea syndrome. The diagnosis of this syndrome can be missed using a conventional polysomnographic setting unless appropriate techniques are applied. The use of an esophageal balloon to monitor inspiratory effort is currently the gold standard. However, other sensitive methods such as the use of a pneumotachograph and, more recently, nasal cannula/pressure transducer systems or on-line monitoring of respiratory impedance with the forced oscillation technique may provide other interesting possibilities. Recognition and characterization of this subgroup of patients within sleep breathing disorders is important because they are symptomatic and may benefit from treatment. Management options to treat UARS comprise all those currently available for sleep apnea/hypopnea syndrome (SAHS). However, the subset of patients classically identified as LIARS that exhibit skeletal craneo-facial abnormalities might possibly obtain further benefit from maxillofacial surgery.

  16. Influences of Casting Pressure Conditions on the Quality and Properties of a Magnesium Cylinder Head Cover Die Casting

    Institute of Scientific and Technical Information of China (English)

    Wenhui LIU; Yangai LIU; Shoumei XIONG; Baicheng LIU; Y. Matsumoto; M. Murakami

    2005-01-01

    Casting pressure conditions have great influences on the casting defects, such as gas porosity, shrinkage porosity and gas holes. A Mg cylinder head cover die casting was used to experimentally study the influences of casting pressure,the loading time and the piston position of pressure intensification on the variation of pressure and the quality of casting. The results show that casting pressure, the loading time and the piston position of pressure intensification have great influences on the pressure variations in the mold, the quality and performance of casting. The external quality, the density and the tensile strength of casting were improved with the increase of casting pressure and the piston position of pressure intensification and the decrease of the loading time of pressure intensification.

  17. Influence of Pressure on SiNx:H Film by LF-PECVD

    Institute of Scientific and Technical Information of China (English)

    Zhen-li Wen; Xiao-ning Cao; Chun-lan Zhou; Wen-jing Wang

    2012-01-01

    Hydrogenated silicon nitride films as an effective antireflection and passivation coating of silicon solar cell were prepared on p-type polished silicon substrate (1.0 Ωcm) by direct LF-PECVD (low frequency plasma enhanced chemical vapor deposition) of Centrotherm.The preferable passivation effect was obtained and the refractive index was in the range of 2.017-2.082.The refractive index of the hydrogenated silicon nitride films became larger with the increase of the pressure. Fourier transform infrared spectroscopy was used to study the pressure influence on the film structural properties.The results highlighted high hydrogen bond and high Si-N bonds density in the film,which were greatly influenced by the pressure.The passivation effect of the films was influenced by the Si dangling bonds density.Finally the effective minority liftetime degradation with time was shown and discussed by considering the relationship between the structural properties and passivation.

  18. PILOT LEAKAGE'S INFLUENCES ON THE PERFORMANCES OF EXTRA HIGH PRESSURE PROPORTIONAL PNEUMATIC VALVE

    Institute of Scientific and Technical Information of China (English)

    Chen Yize; Wang Xuanyin; Xu Zhipeng; Tao Guoliang

    2005-01-01

    A mathematic model is built up to analyze the influences of a pilot valve's leakage on the performances of pneumatic pressure proportional valve, and the performances are simulated by using MATLAB. The results indicate that using slide pilot valve in the valve system is feasible, but the leakage's influences can not be neglected, especially it may induce instability in a low output pressure situation. A pilot valve using too large throttle window will cause the valve oscillate. To improve the working condition of pilot valve, a method adopting different widths of two throttle window is proposed. According to our simulation, this method balances the pressure drop between the two stage throttle ports, and reduces the influences of pilot valve's leakage.

  19. Competition among pressure groups for political influence over the determination of accounting standards

    OpenAIRE

    Klumpes, P J M

    1998-01-01

    This paper integrates prior studies of accounting policy choice and lobbying activities by testing the empirical implications of Becker''s (1983) theory of competition among pressure groups for political influence over the determination of accounting standards. The theory is applied to explain the nature and outcome of conflict among pressure groups representing financial intermediaries (suppliers) and pension fund members (users) over the development of conflicting Australian pension account...

  20. Influence of time and pressure of forming a pattern on mechanical properties

    Directory of Open Access Journals (Sweden)

    T. Pacyniak

    2011-07-01

    Full Text Available In this paper, the technology of forming patterns on a research station equipped with an autoclave A-600 of Polish company GROM is presented. This study was conducted to determine the influence of pressure and time of forming a pattern on the bending strength. Analysis of the results confirmed that bending strength increases with increasing the pressure. The time of forming a pattern has a similar effect.

  1. Influence of gas law on ultrasonic behaviour of porous media under pressure.

    Science.gov (United States)

    Griffiths, S; Ayrault, C

    2010-06-01

    This paper deals with the influence of gas law on ultrasonic behaviour of porous media when the saturating fluid is high pressured. Previous works have demonstrated that ultrasonic transmission through a porous sample with variations of the static pressure (up to 18 bars) of the saturating fluid allows the characterization of high damping materials. In these studies, the perfect gas law was used to link static pressure and density, which is disputable for high pressures. This paper compares the effects of real and perfect gas laws on modeled transmission coefficient for porous foams at these pressures. Direct simulations and a mechanical parameters estimation from minimization show that results are very similar in both cases. The real gas law is thus not necessary to describe the acoustic behaviour of porous media at low ultrasonic frequencies (100 kHz) up to 20 bars.

  2. Influence of coolant temperature and pressure on destructive forces at fuel failure in the NSRR experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kusagaya, Kazuyuki [Global Nuclear Fuel - Japan Co., Ltd., Yokosuka, Kanagawa (Japan); Sugiyama, Tomoyuki; Nakamura, Takehiko; Uetsuka, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-01-01

    In order to design a new experimental capsule to be used in the NSRR (Nuclear Safety Research Reactor) experiment with the temperature and pressure conditions in a typical commercial BWR, coolant temperature and pressure influence is estimated for destructive forces during fuel rod failure in the experiment simulating reactivity-initiated accident (RIA). Considering steam property dependence on temperature and pressure, it is qualitatively shown that the destructive forces in the BWR operation condition are smaller than those in the room temperature and atmospheric pressure condition. Water column velocity, which determines impact by water hammer, is further investigated quantitatively by modeling the experimental system and water hammer phenomenon. As a result, the maximum velocity of the water column in the BWR operation conditions is calculated to be only about 10% of that in the room temperature and atmospheric pressure condition. (author)

  3. Research on the Influence of Orthopaedic Inserts on Pressure Distribution in the Foot

    Directory of Open Access Journals (Sweden)

    Ignas Rutulys

    2011-02-01

    Full Text Available The article examines the influence of individual orthopaedic inserts on pressure distribution in the foot. Feet deformations, types of orthopaedic inserts, materials and pressure in the foot testing methods are discussed. Experimental computer measurements of pressure in the foot before and after the use of inserts have been done. During research, the inserts made of different kinds of materials selected according to human weight, pathology, skin sensitivity and many other reasons has been used. It has been determinated that orthopaedic inserts have a more noticeable impact on children whose feet is adjusted easier if compared with those of adults.Article in Lithuanian

  4. Effect of continuous positive airway pressure treatment on serum angiotensin converting enzyme levels in patients with obesity-associated obstructive sleep apnea syndrome%持续气道正压通气对阻塞性睡眠呼吸暂停综合征患者血清血管紧张素转换酶水平的影响

    Institute of Scientific and Technical Information of China (English)

    沈文富; 李红苗; 王强; 王骏; 蒋冬兰; 严锡祥

    2012-01-01

    目的:探讨持续气道正压通气(continuous positive air-way pressure,CPAP)对阻塞性睡眠呼吸暂停综合征(obstructive sleep apnea syndrome,OSAS)患者血清中血管紧张素转换酶(angiotensin converting enzyme,ACE)水平的影响.方法:根据睡眠期多导睡眠监测中的呼吸暂停低通气指数(apnea hypopnea index,AHI) 检查结果,选择43例符合OSAS诊断标准的患者作为研究对象(OSAS组),测定OSAS组实施CPAP治疗1个月前后ACE水平,与AHI正常者(正常组)比较,并分析OSAS组中ACE与睡眠呼吸紊乱指数的相关性.结果:OSAS组治疗前ACE浓度(23.35±15.62) U/L显著低于正常组(38.95±21.83) U/L (P0.05),相关性分析显示OSAS组中ACE浓度与AHI无明显相关性(r=-0.018,P>0.05).结论:OSAS患者血清中ACE水平与睡眠呼吸紊乱指数无明显相关性,与正常人相比,OSAS患者血清ACE显著降低,CPAP治疗不能影响ACE水平变化.%Objective: To investigate the influence of continuous positive airway pressure( CPAP )treatment on the serum angiotensin converting enzyme levels in patients with obstructive sleep apnea syndrome ( OSAS ). Methods: Based on apnea hypopnea index( AHI ) measured by polysomnography, 43 patients were diagnosed as OSAS( OSAS group ) and enrolled in this study. The serum ACE levels of OSAS group were measured and compared with the subjects without OSAS( normal groups ). In patients with OSAS, the relationship between levels of ACE and AHI were analyzed. Results: Compared with normal group[ ( 38. 95 ±21.83 ) U/L], serum ACE levels in OSAS group[ ( 23.35 ±15.62 ) U/L,P 0. 05 ). No relationship was observed in OSAS group between the ACE levels and AHI levels. Conclusion: The serum ACE levels in OSAS group was significantly higher than in normal group. The CPAP treatment cannot change the ACE level in OSAS patients. The serum ACE levels were not correlated with the AHI levels in OSAS patients.

  5. Compliance Measurements of the Upper Airway in Pediatric Down Syndrome Sleep Apnea Patients.

    Science.gov (United States)

    Subramaniam, Dhananjay Radhakrishnan; Mylavarapu, Goutham; McConnell, Keith; Fleck, Robert J; Shott, Sally R; Amin, Raouf S; Gutmark, Ephraim J

    2016-04-01

    Compliance of soft tissue and muscle supporting the upper airway are two of several factors contributing to pharyngeal airway collapse. We present a novel, minimally invasive method of estimating regional variations in pharyngeal elasticity. Magnetic resonance images for pediatric sleep apnea patients with Down syndrome [9.5 ± 4.3 years (mean age ± standard deviation)] were analyzed to segment airways corresponding to baseline (no mask pressure) and two positive pressures. A three dimensional map was created to evaluate axial and circumferential variation in radial displacements of the airway, dilated by the positive pressures. The displacements were then normalized with respect to the appropriate transmural pressure and radius of an equivalent circle to obtain a measure of airway compliance. The resulting elasticity maps indicated the least and most compliant regions of the pharynx. Airway stiffness of the most compliant region [403 ± 204 (mean ± standard deviation) Pa] decreased with severity of obstructive sleep apnea. The non-linear response of the airway wall to continuous positive airway pressure was patient specific and varied between anatomical locations. We identified two distinct elasticity phenotypes. Patient phenotyping based on airway elasticity can potentially assist clinical practitioners in decision making on the treatments needed to improve airway patency.

  6. Interaction between otorhinolaryngology and orthodontics: correlation between the nasopharyngeal airway and the craniofacial complex

    Science.gov (United States)

    Stellzig-Eisenhauer, Angelika; Meyer-Marcotty, Philipp

    2011-01-01

    In terms of pathophysiology, an anatomically narrow airway is a predisposing factor for obstruction of the upper respiratory tract. The correlation between the nasopharyngeal airway and the craniofacial structures is discussed in this context. Thus a mutual interaction between the pharynx and the mandibular position was demonstrated, whereby the transverse dimension of the nasopharynx was significantly larger in patients with prognathism than in patients with retrognathism. The influence of chronic obstruction of the nasal airway on craniofacial development was also discussed. The form-and-function interaction, which ought to explain the causal relationship between nasal obstruction and craniofacial growth, appears to be of a multifactorial rather than a one-dimensional, linear nature. It is not disputed, however, that expanding the maxilla improves not only nasal volume and nasal flow, but also the subjective sensation of patients, although it is not possible to make a prognostic statement about the extent of this improvement because of the differing reactions of individuals. Orthodontic appliances for advancing the mandible can also be successfully used in the treatment of mild obstructive sleep apnea syndrome. This treatment method should be considered particularly for patients who are unwilling to undergo or cannot tolerate CPAP (continuous positive airway pressure) treatment. PMID:22073108

  7. Influence of Barometric Pressure Changes on Ventilation Conditions in Deep Mines

    Science.gov (United States)

    Wasilewski, Stanisław

    2014-10-01

    Barometric air pressure and its changes have a critical impact on ventilation conditions in the underground workings of deep mines. Changes in pressure are particularly important because they are responsible for the transient states of ventilation conditions, therefore, assessing the scale of pressure change is essential. Unfortunately, previously for many years in the Polish mining industry barometric pressure was recorded only on tapes of mechanical barographs by the ventilation department on the surface and therefore such dependencies of methane concentration due to barometric pressure changes have not been properly documented. Today, after the implementation in mines of instruments enabling the monitoring of absolute pressure in the workings of mines (Wasilewski, 2009) the conditions have been created to study the influence of pressure changes on changes of air parameters in the mine workings. Barometric pressure changes were observed and recorded over a course of approximately two years using monitoring system that utilized high accuracy pressure sensors on the surface and in selected workings of an underground mine. This paper presents a statistical analysis of the data that we generated from assessing pressure changes on the surface and at selected underground points in the mine. In the article, which presents the results of the first part of the study, some examples of when significant changes in pressure prior to the tragic events, which were not accompanied by changes in the methane concentration in mine workings, will also be shown. Interestingly, we found that the relationship between methane ignitions and explosions in longwall gob mined via the cave-in method is associated with changes in the barometric pressure. Several instances of methane ignitions and explosions in the gob of cave-in longwalls in recent years were compared with background barometric pressure changes. Research carried out in within the strategic project "Improving work safety in

  8. How does multilevel upper airway surgery influence the lives of dogs with severe brachycephaly? Results of a structured pre- and postoperative owner questionnaire.

    Science.gov (United States)

    Pohl, Sabine; Roedler, Frauke S; Oechtering, Gerhard U

    2016-04-01

    Brachycephalic airway syndrome in dogs is typified by a variety of anatomical abnormalities causing a diverse spectrum of clinical signs of varying intensity. This variability makes the assessment of the surgical outcome after upper airway surgery difficult. Using a structured questionnaire, the present study investigated the dog owner-perceived severity and frequency of a broad spectrum of welfare-relevant impairments 2 weeks before and 6 months after brachycephalic dogs underwent a recently developed multi-level upper airway surgery. All dogs underwent surgical treatment of stenotic nares (ala-vestibuloplasty), the nasal cavity (laser-assisted turbinectomy, LATE), the pharynx (palatoplasty and tonsillotomy), and if indicated, laryngeal surgery (laser-assisted ablation of everted ventricles and partial cuneiformectomy). Owners of brachycephalic dogs (n = 102) referred for upper airway surgery were eligible to participate. Questionnaire data from owners of 37 Pugs and 25 French bulldogs were evaluated. In all dogs, the clinical signs associated with brachycephaly improved markedly after surgery. Most encouraging was the striking reduction in life-threatening events by 90% (choking fits decreased from 60% to 5% and collapse from 27% to 3%). The incidence of sleeping problems decreased from 55% to 3%, and the occurrence of breathing sounds declined by approximately 50%. There was a marked improvement in exercise tolerance and a modest improvement in heat tolerance. Dogs with severe brachycephaly benefitted substantially from multi-level surgery, and there were particular improvements in the incidences of severe impairment and life-threatening events. However, despite the marked improvement perceived by dog owners, these dogs remained clinically affected and continued to show welfare-relevant impairments caused by these hereditary disorders.

  9. Airway management in patients with deep neck infections

    Science.gov (United States)

    Cho, Soo Young; Woo, Jae Hee; Kim, Yoon Jin; Chun, Eun Hee; Han, Jong In; Kim, Dong Yeon; Baik, Hee Jung; Chung, Rack Kyung

    2016-01-01

    Abstract Securing the airway in patients undergoing surgical intervention to control a deep neck infection (DNI) is challenging for anesthesiologists due to the distorted airway anatomy, limited mouth opening, tissue edema, and immobility. It is critical to assess the risk of a potential difficult airway and prepare the most appropriate airway management method. We reviewed our anesthetic experiences managing patients with DNIs, focusing on the need for video-laryngoscope or awake fiberoptic intubation beyond a standard intubation from the anesthesiologist's perspective. When patients had infections in the masticatory space, mouth of floor, oropharyngeal mucosal space, or laryngopharynx, their airways tended to be managed using methods requiring more effort by the anesthesiologists, and more extensive equipment preparation, compared with use of a standard laryngoscope. The degree to which the main lesion influenced the airway anatomy, especially at the level of epiglottis and aryepiglottic fold was related to the airway management method selected. When managing the airways of patients undergoing surgery for DNIs under general anesthesia, anesthesiologists should use imaging with computed tomography to evaluate the preoperative airway status and a comprehensive understanding of radiological findings, comorbidities, and patients’ symptoms is needed. PMID:27399122

  10. Upper Airway Elasticity Estimation in Pediatric Down Syndrome Sleep Apnea Patients Using Collapsible Tube Theory.

    Science.gov (United States)

    Subramaniam, Dhananjay Radhakrishnan; Mylavarapu, Goutham; McConnell, Keith; Fleck, Robert J; Shott, Sally R; Amin, Raouf S; Gutmark, Ephraim J

    2016-05-01

    Elasticity of the soft tissues surrounding the upper airway lumen is one of the important factors contributing to upper airway disorders such as snoring and obstructive sleep apnea. The objective of this study is to calculate patient specific elasticity of the pharynx from magnetic resonance (MR) images using a 'tube law', i.e., the relationship between airway cross-sectional area and transmural pressure difference. MR imaging was performed under anesthesia in children with Down syndrome (DS) and obstructive sleep apnea (OSA). An airway segmentation algorithm was employed to evaluate changes in airway cross-sectional area dilated by continuous positive airway pressure (CPAP). A pressure-area relation was used to make localized estimates of airway wall stiffness for each patient. Optimized values of patient specific Young's modulus for tissue in the velopharynx and oropharynx, were estimated from finite element simulations of airway collapse. Patient specific deformation of the airway wall under CPAP was found to exhibit either a non-linear 'hardening' or 'softening' behavior. The localized airway and tissue elasticity were found to increase with increasing severity of OSA. Elasticity based patient phenotyping can potentially assist clinicians in decision making on CPAP and airway or tissue elasticity can supplement well-known clinical measures of OSA severity.

  11. The influence of preferential flow on pressure propagation and landslide triggering of the Rocca Pitigliana landslide

    Science.gov (United States)

    Shao, Wei; Bogaard, Thom; Bakker, Mark; Berti, Matteo

    2016-12-01

    The fast pore water pressure response to rain events is an important triggering factor for slope instability. The fast pressure response may be caused by preferential flow that bypasses the soil matrix. Currently, most of the hydro-mechanical models simulate pore water pressure using a single-permeability model, which cannot quantify the effects of preferential flow on pressure propagation and landslide triggering. Previous studies showed that a model based on the linear-diffusion equation can simulate the fast pressure propagation in near-saturated landslides such as the Rocca Pitigliana landslide. In such a model, the diffusion coefficient depends on the degree of saturation, which makes it difficult to use the model for predictions. In this study, the influence of preferential flow on pressure propagation and slope stability is investigated with a 1D dual-permeability model coupled with an infinite-slope stability approach. The dual-permeability model uses two modified Darcy-Richards equations to simultaneously simulate the matrix flow and preferential flow in hillslopes. The simulated pressure head is used in an infinite-slope stability analysis to identify the influence of preferential flow on the fast pressure response and landslide triggering. The dual-permeability model simulates the height and arrival of the pressure peak reasonably well. Performance of the dual-permeability model is as good as or better than the linear-diffusion model even though the dual-permeability model is calibrated for two single pulse rain events only, while the linear-diffusion model is calibrated for each rain event separately. In conclusion, the 1D dual-permeability model is a promising tool for landslides under similar conditions.

  12. Emergency airway puncture - slideshow

    Science.gov (United States)

    ... presentations/100113.htm Emergency airway puncture - series—Normal anatomy To ... larynx is a tubular structure in the neck, through which air passes to the lungs. The thryoid and cricoid cartilage form the narrowest ...

  13. Emergency airway puncture

    Science.gov (United States)

    ... inserted into the throat, just below the Adam's apple (cricoid cartilage), into the airway. In a hospital, ... Choking Browse the Encyclopedia A.D.A.M., Inc. is accredited by URAC, also known as the ...

  14. High Blood Pressure in Adults with Disabilities: Influence of Gender, Body Weight and Health Behaviors

    Science.gov (United States)

    Lin, Lan-Ping; Liu, Chien-Ting; Liou, Shih-Wen; Hsu, Shang-Wei; Lin, Jin-Ding

    2012-01-01

    The aims of this study were to explore the mean and distribution of systolic and diastolic blood pressure, and to examine the influence of gender, body weight and health behaviors on hypertension in adults with disabilities. We analyzed the 2010 annual community health examination chart of adults with disabilities in east Taiwan. The study samples…

  15. Pressure-Sensitive Adhesives under the Influence of Relative Humidity: Inner Structure and Failure Mechanisms.

    Science.gov (United States)

    Schindler, Markus; Koller, Manuel; Müller-Buschbaum, Peter

    2015-06-17

    Model pressure-sensitive adhesive (PSA) films of the statistical copolymer P(EHA-stat-20MMA), which comprises 80% ethylhexyl acrylate (EHA) and 20% methyl methacrylate (MMA), are studied. The PSA films are stored under different relative humidities from postproduction treatment, which also influence the tack performance. This finding is supported by tack measurements using punches with different roughness.

  16. Influence of Tip Clearance on Pressure Fluctuation in Low Specific Speed Mixed-Flow Pump Passage

    Directory of Open Access Journals (Sweden)

    Wenwu Zhang

    2017-01-01

    Full Text Available To explore the influence of tip clearance on pressure fluctuation in a low specific speed mixed-flow pump, tip clearances δ of 0.25 mm, 0.75 mm and 1.00 mm, along with no tip clearance, were selected. The reliability of the simulation was verified by comparison with the experimental data of external characteristics and fluctuation in the guide vane passage. Through ANSYS-CFX, MATLAB code and fast Fourier transform (FFT algorithm, pressure fluctuation characteristics in this pump were obtained. The results show that pressure fluctuation exists in all conditions due to the rotor-stator interaction. Under the no tip clearance and tip clearance conditions, the maximum fluctuation value was located near the guide inlet and impeller outlet, respectively. Clearance leakage had less influence on pressure fluctuation at the impeller inlet and central regions within a certain range of the clearance; beyond this range, fluctuations in the whole flow passage increased significantly, while the clearance variation had less effect on fluctuation in the guide vane. When the tip clearance value was 1.00 mm, pressure fluctuation of the shroud at the impeller inlet section suddenly increases, which was closely related to the obvious leakage vortexes and a larger low pressure area.

  17. Influence of physical characteristics and ingredients on the minimum burning pressure of ammonium nitrate emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, R.; Goldthorp, S.; Badeen, C.M.; Johnson, C.; Feng, H. [Natural Resources Canada, Ottawa, ON (Canada). Canadian Explosives Research Laboratory; Chan, S.K. [Orica Canada Inc., Brownsburg-Chatham, PQ (Canada)

    2009-05-15

    The sustained combustion of ammonium nitrate water-based explosives (AWEs) will not occur when pressures are kept below specific threshold values. The minimum burning pressure (MBP) is used to estimate safety operating pressures for the processing, manufacturing and handling of AWEs. MBP measurements were performed for various commercially available AWEs. The purpose of the study was to determine how common formulation changes may affect the MBP of AWEs and how changes in testing methodologies will influence obtained MBP values. The study examined how the testing geometries of products containing glass microspheres altered the combustion behaviour of the AWEs used in the test. The influence of temperature and initial viscosity on the MBP was also investigated. The study showed that re-solidified glass was found in the bottom cap of the cell during vertical testing geometries. It was concluded that slow decomposition events were eliminated when using a horizontal testing geometry. 12 refs., 8 figs.

  18. Airway management in trauma.

    Science.gov (United States)

    Langeron, O; Birenbaum, A; Amour, J

    2009-05-01

    Maintenance of a patent and prevention of aspiration are essential for the management of the trauma patient, that requires experienced physicians in airway control techniques. Difficulties of the airway control in the trauma setting are increased by the vital failures, the risk of aspiration, the potential cervical spine injury, the combative patient, and the obvious risk of difficult tracheal intubation related to specific injury related to the trauma. Endotracheal intubation remains the gold standard in trauma patient airway management and should be performed via the oral route with a rapid sequence induction and a manual in-line stabilization maneuver, to decrease the risks previously mentioned. Different techniques to control the airway in trauma patients are presented: improvement of the laryngoscopic vision, lighted stylet tracheal intubation, retrograde technique for orotracheal intubation, the laryngeal mask and the intubating laryngeal mask airways, the combitube and cricothyroidotomy. Management of the airway in trauma patients requires regular training in these techniques and the knowledge of complementary techniques allowing tracheal intubation or oxygenation to overcome difficult intubation and to prevent major complications as hypoxemia and aspiration.

  19. 持续正压通气在重症毛细支气管炎中的应用%The clinical application of continuous positive airway pressure in severe bronchiolitis

    Institute of Scientific and Technical Information of China (English)

    史瑞鹤; 刘恩梅

    2015-01-01

    毛细支气管炎是小婴儿最常见的下呼吸道感染性疾病,目前尚无特异性治疗,主要以对症支持治疗为主,近年来其治疗方法的探索一直是临床热点。持续正压通气(CPAP)作为一种安全、有效、无创的治疗方法,能有效缓解毛细支气管炎患儿的症状,改善预后,其临床应用越来越受到重视。文章对持续正压通气在重症毛细支气管炎患儿中的临床应用进行综述。%Bronchiolitis is the most common lower respiratory tract disease in infants. There is no speciifc treatment for it and the treatment is mainly supportive. The management of bronchiolitis is the clinical hotspot recently. Continuous positive airway pressure (CPAP) has gained more attention in clinical application as it is a safe, effective, and noninvasive method and can effectively relieve symptoms of bronchiolitis and improve prognosis. This paper reviews the clinical application of CPAP in infants with severe bronchiolitis.

  20. Influence of air pressure on mechanical effect of laser plasma shock wave

    Institute of Scientific and Technical Information of China (English)

    Zhang Yu-Zhu; Wang Guang-An; Zhu Jin-Rong; Shen Zhong-Hua; Ni Xiao-Wu; Lu Jian

    2007-01-01

    The influence of air pressure on mechanical effect of laser plasma shock wave in a vacuum chamber produced by a Nd:YAG laser has been studied. The laser pulses with pulse width of 10ns and pulse energy of about 320mJ at 1.06μm wavelength is focused on the aluminium target mounted on a ballistic pendulum, and the air pressure in the chamber changes from 2.8 × 103 to 1.01×105pa. The experimental results show that the impulse coupling coefficient changes as the air pressure and the distance of the target from focus change. The mechanical effects of the plasma shock wave on the target are analysed at different distances from focus and the air pressure.

  1. INFLUENCE OF STEAM PRESSURE ON CHEMICAL CHANGES OF HEAT-TREATED MONGOLIAN PINE WOOD

    Directory of Open Access Journals (Sweden)

    Tao Ding

    2011-04-01

    Full Text Available Properties of heat-treated wood have been studied extensively in recent years. However, study on wood that has been treated in pressurized steam is limited, as most wood heat treatments are carried out in atmospheric steam. The main purpose of this study was to explore the influence of steam pressure on chemical changes of heat-treated wood. Wet chemical analysis, elemental analysis, and FTIR analysis were performed to investigate the changes of cell wall components of Mongolian pine wood. Samples treated in pressurized steam had lower percentages of polysaccharides and higher percentages of lignin compared to those treated in atmospheric steam, indicating greater chemical changes during the treatment. It was also found that thermal degradation of both samples was modest at the treatment temperature of 205 °C. These results help to explain the better dimensional stability and limited strength deterioration of wood treated in pressurized steam.

  2. High-pressure processing of Gorgonzola cheese: influence on Listeria monocytogenes inactivation and on sensory characteristics.

    Science.gov (United States)

    Carminati, D; Gatti, M; Bonvini, B; Neviani, E; Mucchetti, G

    2004-08-01

    The presence of Listeria monocytogenes on the rind of Gorgonzola cheese is difficult to avoid. This contamination can easily occur as a consequence of handling during ripening. The aims of this study were to determine the efficiency of high-pressure processing (HPP) for inactivation of L. monocytogenes on cheese rind and to evaluate the influence of HPP treatments on sensory characteristics. Gorgonzola cheese rinds, after removal, were inoculated (about 7.0 log CFU/g) with L. monocytogenes strains previously isolated from other Gorgonzola cheeses. The inoculated cheese rinds were processed with an HPP apparatus under conditions of pressure and time ranging from 400 to 700 MPa for 1 to 15 min. Pressures higher than 600 MPa for 10 min or 700 MPa for 5 min reduced L. monocytogenes more than 99%. A reduction higher than 99.999% was achieved pressurizing cheese rinds at 700 MPa for 15 min. Lower pressure or time treatments were less effective and varied in effectiveness with the cheese sample. Changes in sensory properties possibly induced by the HPP were evaluated on four different Gorgonzola cheeses. A panel of 18 members judged the treated and untreated cheeses in a triangle test. Only one of the four pressurized cheeses was evaluated as different from the untreated sample. HPP was effective in the reduction of L. monocytogenes on Gorgonzola cheese rinds without significantly changing its sensory properties. High-pressure technology is a useful tool to improve the safety of this type of cheese.

  3. Properties of RF sputtered cadmium telluride (CdTe) thin films: Influence of deposition pressure

    Science.gov (United States)

    Kulkarni, R. R.; Pawbake, A. S.; Waykar, R. G.; Rondiya, S. R.; Jadhavar, A. A.; Pandharkar, S. M.; Karpe, S. D.; Diwate, K. D.; Jadkar, S. R.

    2016-04-01

    Influence of deposition pressure on structural, morphology, electrical and optical properties of CdTe thin films deposited at low substrate temperature (100°C) by RF magnetron sputtering was investigated. The formation of CdTe was confirmed by low angle XRD and Raman spectroscopy. The low angle XRD analysis revealed that the CdTe films have zinc blende (cubic) structure with crystallites having preferred orientation in (111) direction. Raman spectra show the longitudinal optical (LO) phonon mode peak ˜ 165.4 cm-1 suggesting high quality CdTe film were obtained over the entire range of deposition pressure studied. Scanning electron microscopy analysis showed that films are smooth, homogenous, and crack-free with no evidence of voids. The EDAX data revealed that CdTe films deposited at low deposition pressure are high-quality stoichiometric. However, for all deposition pressures, films are rich in Cd relative to Te. The UV-Visible spectroscopy analysis show the blue shift in absorption edge with increasing the deposition pressure while the band gap show decreasing trend. The highest electrical conductivity was obtained for the film deposited at deposition pressure 1 Pa which indicates that the optimized deposition pressure for our sputtering unit is 1 Pa. Based on the experimental results, these CdTe films can be useful for the application in the flexible solar cells and other opto-electronic devices.

  4. Airway Responsiveness to Psychological Processes in Asthma and Health

    Directory of Open Access Journals (Sweden)

    Thomas eRitz

    2012-09-01

    Full Text Available Psychosocial factors have been found to impact airway pathophysiology in respiratory disease with considerable consistency. Influences on airway mechanics have been studied particularly well. The goal of this article is to review the literature on airway responses to psychological stimulation, discuss potential pathways of influence, and present a well-established emotion-induction paradigm to study airway obstruction elicited by unpleasant stimuli. Observational studies have found systematic associations between lung function and daily mood changes. The laboratory –based paradigm of bronchoconstrictive suggestion has been used successfully to elicit airway obstruction in a substantial proportion of asthmatic individuals. Other studies have demonstrated an enhancement of airway responses to standard airway challenges with exercise, allergens, or methacholine. Standardized emotion-induction techniques have consistently shown airway constriction during unpleasant stimulation, with surgery, blood and injury stimuli being particularly powerful. Findings with various forms of stress induction have been more mixed. A number of methodological factors may account for variability across studies, such as choice of measurement technique, temporal association between stimulation and measurement, and the specific quality and intensity of the stimulus material, in particular the extent of implied action-orientation. Research has also begun to elucidate physiological processes associated with psychologically induced airway responses, with vagal excitation and ventilatory influences being the most likely candidate pathways, whereas the role of specific central nervous system pathways and inflammatory processes has been less studied. The technique of emotion-induction using films has the potential to become a standardized challenge paradigm for the further exploration of airway hyperresponsiveness mediated by central nervous system processes.

  5. Seasonal emanation of radon at Ghuttu, northwest Himalaya: Differentiation of atmospheric temperature and pressure influences.

    Science.gov (United States)

    Kamra, Leena

    2015-11-01

    Continuous monitoring of radon along with meteorological parameters has been carried out in a seismically active area of Garhwal region, northwest Himalaya, within the frame work of earthquake precursory research. Radon measurements are carried out by using a gamma ray detector installed in the air column at a depth of 10m in a 68m deep borehole. The analysis of long time series for 2006-2012 shows strong seasonal variability masked by diurnal and multi-day variations. Isolation of a seasonal cycle by minimising short-time by 31 day running average shows a strong seasonal variation with unambiguous dependence on atmospheric temperature and pressure. The seasonal characteristics of radon concentrations are positively correlated to atmospheric temperature (R=0.95) and negatively correlated to atmospheric pressure (R=-0.82). The temperature and pressure variation in their annual progressions are negatively correlated. The calculations of partial correlation coefficient permit us to conclude that atmospheric temperature plays a dominant role in controlling the variability of radon in borehole, 71% of the variability in radon arises from the variation in atmospheric temperature and about 6% of the variability is contributed by atmospheric pressure. The influence of pressure variations in an annual cycle appears to be a pseudo-effect, resulting from the negative correlation between temperature and pressure variations. Incorporation of these results explains the varying and even contradictory claims regarding the influence of the pressure variability on radon changes in the published literature. Temperature dependence, facilitated by the temperature gradient in the borehole, controls the transportation of radon from the deep interior to the surface.

  6. Modeling the dynamics of airway constriction: effects of agonist transport and binding.

    Science.gov (United States)

    Amin, Samir D; Majumdar, Arnab; Frey, Urs; Suki, Béla

    2010-08-01

    Recent advances have revealed that during exogenous airway challenge, airway diameters cannot be adequately predicted by their initial diameters. Furthermore, airway diameters can also vary greatly in time on scales shorter than a breath. To better understand these phenomena, we developed a multiscale model that allowed us to simulate aerosol challenge in the airways during ventilation. The model incorporates agonist-receptor binding kinetics to govern the temporal response of airway smooth muscle contraction on individual airway segments, which, together with airway wall mechanics, determines local airway caliber. Global agonist transport and deposition are coupled with pressure-driven flow, linking local airway constrictions with global flow dynamics. During the course of challenge, airway constriction alters the flow pattern, redistributing the agonist to less constricted regions. This results in a negative feedback that may be a protective property of the normal lung. As a consequence, repetitive challenge can cause spatial constriction patterns to evolve in time, resulting in a loss of predictability of airway diameters. Additionally, the model offers new insights into several phenomena including the intra- and interbreath dynamics of airway constriction throughout the tree structure.

  7. Wind interference between two high-rise building models: On the influence of shielding, channeling and buffeting on peak pressures

    NARCIS (Netherlands)

    Bronkhorst, A.J.; Geurts, C.P.W.; Bentum, C.A. van; Blocken, B.

    2014-01-01

    The influence of interference between two high-rise building models on the minimum peak pressures was investigated in an atmospheric boundary layer wind tunnel. Pressure measur€ments were performed on a square model with an aspect ratio of 1 to 4. The influence of an interfering model with the same

  8. Influence of pressure-relief insoles developed for loaded gait (backpackers and obese people) on plantar pressure distribution and ground reaction forces.

    Science.gov (United States)

    Peduzzi de Castro, Marcelo; Abreu, Sofia; Pinto, Viviana; Santos, Rubim; Machado, Leandro; Vaz, Mario; Vilas-Boas, João Paulo

    2014-07-01

    The aims of this study were to test the effects of two pressure relief insoles developed for backpackers and obese people on the ground reaction forces (GRF) and plantar pressure peaks during gait; and to compare the GRF and plantar pressures among normal-weight, backpackers, and obese participants. Based on GRF, plantar pressures, and finite element analysis two insoles were manufactured: flat cork-based insole with (i) corkgel in the rearfoot and forefoot (SLS1) and with (ii) poron foam in the great toe and lateral forefoot (SLS2). Gait data were recorded from 21 normal-weight/backpackers and 10 obese participants. The SLS1 did not influence the GRF, but it relieved the pressure peaks for both backpackers and obese participants. In SLS2 the load acceptance GRF peak was lower; however, it did not reduce the plantar pressure peaks. The GRF and plantar pressure gait pattern were different among the normal-weight, backpackers and obese participants.

  9. Influence of Pressure on Physical Property of Ammonia Borane and its Re-hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jiuhua [Florida Intl Univ., Miami, FL (United States)

    2015-08-14

    The project systematically studied the high pressure behavior of ammonia borane and its derivative lithium amidoborane. Phase transitions in these materials are investigated in the pressure range up to 20 GPa and temperature range from 80 K to 400K. A number of new phase transitions are discovered in this pressure and temperature range including a second order transformation at 5 GPa and a first order transformation at 12 GPa at room temperature, and four new transitions at high pressure and low temperatures. The Clapeyron slopes for both pressure-induce tetragonal (I4mm) phase to orthorhombic (Cmc21) phase and temperature-induce tetragonal (I4mm) phase to orthorhombic (Pmn21) phase are determined to be positive, indicating these phase transitions are exothermic. This result demonstrates that the high pressure orthorhombic phase of ammonia borane has lower enthalpy than that of tetragonal phase at ambient conditions. If we assume decomposition from the orthorhombic phase yields the same products as that from the tetragonal phase, the decomposition of the orthorhombic phase will be less exothermic. Therefore rehydrogenation from the decomposed product into the orthorhombic phase at high pressure may become easier. The project also studied the influences of nanoconfinement on the phase transitions. Comparative study using Raman spectroscopy indicates that the temperature induced I4mm to Pmn21 transition is suppressed from 217 K to 195 K when the sample is confined in SBA15 (7-9 nm pore size). When the pore size is reduced from 7-9 nm to 3-4 nm, this transition is totally suppressed in the temperature down to 80 K. A similar influence of the nanoconfiement on pressure induced phase transitions is also observed using Raman spectroscopy. The phase boundary between the I4mm phase and high pressure Cmc21 phase at ambient temperature shifts from 0.9 GPa to 0.5 GPa; and that between the Cmc21 phase and higher pressure P21 phase shifts from 10.2 GPa to 9.7 GPa.

  10. Integrated care pathways for airway diseases (AIRWAYS-ICPs)

    NARCIS (Netherlands)

    Bousquet, J.; Addis, A.; Adcock, I.; Agache, I.; Agusti, A.; Alonso, A.; Annesi-Maesano, I.; Anto, J. M.; Bachert, C.; Baena-Cagnani, C. E.; Bai, C.; Baigenzhin, A.; Barbara, C.; Barnes, P. J.; Bateman, E. D.; Beck, L.; Bedbrook, A.; Bel, E. H.; Benezet, O.; Bennoor, K. S.; Benson, M.; Bernabeu-Wittel, M.; Bewick, M.; Bindslev-Jensen, C.; Blain, H.; Blasi, F.; Bonini, M.; Bonini, S.; Boulet, L. P.; Bourdin, A.; Bourret, R.; Bousquet, P. J.; Brightling, C. E.; Briggs, A.; Brozek, J.; Buh, R.; Bush, A.; Caimmi, D.; Calderon, M.; Calverley, P.; Camargos, P. A.; Camuzat, T.; Canonica, G. W.; Carlsen, K. H.; Casale, T. B.; Cazzola, M.; Sarabia, A. M. Cepeda; Cesario, A.; Chen, Y. Z.; Chkhartishvili, E.; Chavannes, N. H.; Chiron, R.; Chuchalin, A.; Chung, K. F.; Cox, L.; Crooks, G.; Crooks, M. G.; Cruz, A. A.; Custovic, A.; Dahl, R.; Dahlen, S. E.; De Blay, F.; Dedeu, T.; Deleanu, D.; Demoly, P.; Devillier, P.; Didier, A.; Dinh-Xuan, A. T.; Djukanovic, R.; Dokic, D.; Douagui, H.; Dubakiene, R.; Eglin, S.; Elliot, F.; Emuzyte, R.; Fabbri, L.; Wagner, A. Fink; Fletcher, M.; Fokkens, W. J.; Fonseca, J.; Franco, A.; Frith, P.; Furber, A.; Gaga, M.; Garces, J.; Garcia-Aymerich, J.; Gamkrelidze, A.; Gonzales-Diaz, S.; Gouzi, F.; Guzman, M. A.; Haahtela, T.; Harrison, D.; Hayot, M.; Heaney, L. G.; Heinrich, J.; Hellings, P. W.; Hooper, J.; Humbert, M.; Hyland, M.; Iaccarino, G.; Jakovenko, D.; Jardim, J. R.; Jeandel, C.; Jenkins, C.; Johnston, S. L.; Jonquet, O.; Joos, G.; Jung, K. S.; Kalayci, O.; Karunanithi, S.; Keil, T.; Khaltaev, N.; Kolek, V.; Kowalski, M. L.; Kull, I.; Kuna, P.; Kvedariene, V.; Le, L. T.; Carlsen, K. C. Lodrup; Louis, R.; MacNee, W.; Mair, A.; Majer, I.; Manning, P.; Keenoy, E. de Manuel; Masjedi, M. R.; Meten, E.; Melo-Gomes, E.; Menzies-Gow, A.; Mercier, G.; Mercier, J.; Michel, J. P.; Miculinic, N.; Mihaltan, F.; Milenkovic, B.; Molimard, M.; Mamas, I.; Montilla-Santana, A.; Morais-Almeida, M.; Morgan, M.; N'Diaye, M.; Nafti, S.; Nekam, K.; Neou, A.; Nicod, L.; O'Hehir, R.; Ohta, K.; Paggiaro, P.; Palkonen, S.; Palmer, S.; Papadopoulos, N. G.; Papi, A.; Passalacqua, G.; Pavord, I.; Pigearias, B.; Plavec, D.; Postma, D. S.; Price, D.; Rabe, K. F.; Pontal, F. Radier; Redon, J.; Rennard, S.; Roberts, J.; Robine, J. M.; Roca, J.; Roche, N.; Rodenas, F.; Roggeri, A.; Rolland, C.; Rosado-Pinto, J.; Ryan, D.; Samolinski, B.; Sanchez-Borges, M.; Schunemann, H. J.; Sheikh, A.; Shields, M.; Siafakas, N.; Sibille, Y.; Similowski, T.; Small, I.; Sola-Morales, O.; Sooronbaev, T.; Stelmach, R.; Sterk, P. J.; Stiris, T.; Sud, P.; Tellier, V.; To, T.; Todo-Bom, A.; Triggiani, M.; Valenta, R.; Valero, A. L.; Valiulis, A.; Valovirta, E.; Van Ganse, E.; Vandenplas, O.; Vasankari, T.; Vestbo, J.; Vezzani, G.; Viegi, G.; Visier, L.; Vogelmeier, C.; Vontetsianos, T.; Wagstaff, R.; Wahn, U.; Wallaert, B.; Whalley, B.; Wickman, M.; Williams, D. M.; Wilson, N.; Yawn, B. P.; Yiallouros, P. K.; Yorgancioglu, A.; Yusuf, O. M.; Zar, H. J.; Zhong, N.; Zidarn, M.; Zuberbier, T.

    2014-01-01

    The objective of Integrated Care Pathways for Airway Diseases (AIRWAYS-ICPs) is to launch a collaboration to develop multi-sectoral care pathways for chronic respiratory diseases in European countries and regions. AIRWAYS-ICPs has strategic relevance to the European Union Health Strategy and will ad

  11. Comparison of Supreme Laryngeal Mask Airway and ProSeal Laryngeal Mask Airway during Cholecystectomy

    OpenAIRE

    2012-01-01

    Objective: This study compared the safety and efficacy of the Supreme Laryngeal Mask Airway (S-LMA) with that of the ProSeal-LMA (P-LMA) in laparoscopic cholecystectomy. Material and Methods: Sixty adults were randomly allocated. Following anaesthesia induction, experienced LMA users inserted the airway devices. Results: Oropharyngeal leak pressure was similar in groups (S-LMA, 27.8±2.9 cmH20; P-LMA, 27.0±4.7 cmH20; p=0.42) and did not change...

  12. Comparison of Supreme Laryngeal Mask Airway and ProSeal Laryngeal Mask Airway during Cholecystectomy

    OpenAIRE

    2012-01-01

    Objective: This study compared the safety and efficacy of the Supreme Laryngeal Mask Airway (S-LMA) with that of the ProSeal-LMA (P-LMA) in laparoscopic cholecystectomy.Material and Methods: Sixty adults were randomly allocated. Following anaesthesia induction, experienced LMA users inserted the airway devices. Results: Oropharyngeal leak pressure was similar in groups (S-LMA, 27.8±2.9 cmH20; P-LMA, 27.0±4.7 cmH20; p=0.42) and did not change during the induction of and throughout pneumoperit...

  13. Propagule pressure and stream characteristics influence introgression: Cutthroat and rainbow trout in British Columbia

    Science.gov (United States)

    Bennett, S.N.; Olson, J.R.; Kershner, J.L.; Corbett, P.

    2010-01-01

    Hybridization and introgression between introduced and native salmonids threaten the continued persistence of many inland cutthroat trout species. Environmental models have been developed to predict the spread of introgression, but few studies have assessed the role of propagule pressure. We used an extensive set of fish stocking records and geographic information system (GIS) data to produce a spatially explicit index of potential propagule pressure exerted by introduced rainbow trout in the Upper Kootenay River, British Columbia, Canada. We then used logistic regression and the information-theoretic approach to test the ability of a set of environmental and spatial variables to predict the level of introgression between native westslope cutthroat trout and introduced rainbow trout. Introgression was assessed using between four and seven co-dominant, diagnostic nuclear markers at 45 sites in 31 different streams. The best model for predicting introgression included our GIS propagule pressure index and an environmental variable that accounted for the biogeoclimatic zone of the site (r2 = 0.62). This model was 1.4 times more likely to explain introgression than the next-best model, which consisted of only the propagule pressure index variable. We created a composite model based on the model-averaged results of the seven top models that included environmental, spatial, and propagule pressure variables. The propagule pressure index had the highest importance weight (0.995) of all variables tested and was negatively related to sites with no introgression. This study used an index of propagule pressure and demonstrated that propagule pressure had the greatest influence on the level of introgression between a native and introduced trout in a human-induced hybrid zone. ?? 2010 by the Ecological Society of America.

  14. Influence of high glycemic index and glycemic load diets on blood pressure during adolescence.

    Science.gov (United States)

    Gopinath, Bamini; Flood, Victoria M; Rochtchina, Elena; Baur, Louise A; Smith, Wayne; Mitchell, Paul

    2012-06-01

    We aimed to prospectively examine the association between the glycemic index and glycemic load of foods consumed and the dietary intakes of carbohydrates, sugars, fiber, and principal carbohydrate-containing food groups (eg, breads, cereals, and sugary drinks) with changes in blood pressure during adolescence. A total of 858 students aged 12 years at baseline (422 girls and 436 boys) were examined from 2004-2005 to 2009-2011. Dietary data were assessed from validated semiquantitative food frequency questionnaires. Blood pressure was measured using a standard protocol. In girls, after adjusting for age, ethnicity, parental education, parental history of hypertension, baseline height, baseline blood pressure, change in body mass index, and time spent in physical and sedentary activities, each 1-SD (1-SD = 7.10 g/d) increase in baseline dietary intake of total fiber was associated with a 0.96-, 0.62-, and 0.75-mmHg decrease in mean systolic (P = 0.02), diastolic (P = 0.01), and arterial blood pressures (P = 0.002), respectively, 5 years later. In girls, each 1-SD increase in dietary glycemic index, glycemic load, carbohydrate, and fructose was concurrently related to increases of 1.81 (P = 0.001), 4.02 (P = 0.01), 4.74 (P = 0.01), and 1.80 mm Hg (P = 0.03) in systolic blood pressure, respectively, >5 years. Significant associations between carbohydrate nutrition variables and blood pressure were not observed among boys. Excessive dietary intake of carbohydrates, specifically from high glycemic index/glycemic load foods, could adversely influence blood pressure, particularly in girls, whereas fiber-rich diets may be protective against elevated blood pressure during adolescence.

  15. Regime change thresholds in flute-like instruments: influence of the mouth pressure dynamics

    CERN Document Server

    Terrien, Soizic; Vergez, Christophe; Fabre, Benoît

    2014-01-01

    Since they correspond to a jump from a given note to another one, the mouth pressure thresholds leading to regime changes are particularly important quantities in flute-like instruments. In this paper, a comparison of such thresholds between an artificial mouth, an experienced flutist and a non player is provided. It highlights the ability of the experienced player to considerabily shift regime change thresholds, and thus to enlarge its control in terms of nuances and spectrum. Based on recent works on other wind instruments and on the theory of dynamic bifurcations, the hypothe- sis is tested experimentally and numerically that the dynamics of the blowing pressure influences regime change thresholds. The results highlight the strong influence of this parameter on thresholds, suggesting its wide use by experienced musicians. Starting from these observations and from an analysis of a physical model of flute-like instruments, involving numerical continuation methods and Floquet stability analysis, a phenomenolo...

  16. Virtually simulated social pressure influences early visual processing more in low compared to high autonomous participants.

    Science.gov (United States)

    Trautmann-Lengsfeld, Sina Alexa; Herrmann, Christoph Siegfried

    2014-02-01

    In a previous study, we showed that virtually simulated social group pressure could influence early stages of perception after only 100  ms. In the present EEG study, we investigated the influence of social pressure on visual perception in participants with high (HA) and low (LA) levels of autonomy. Ten HA and ten LA individuals were asked to accomplish a visual discrimination task in an adapted paradigm of Solomon Asch. Results indicate that LA participants adapted to the incorrect group opinion more often than HA participants (42% vs. 30% of the trials, respectively). LA participants showed a larger posterior P1 component contralateral to targets presented in the right visual field when conforming to the correct compared to conforming to the incorrect group decision. In conclusion, our ERP data suggest that the group context can have early effects on our perception rather than on conscious decision processes in LA, but not HA participants.

  17. Simulation of the Influences of the Pressure Ratio and Cu Vapour on SF6 Arc Characteristics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian; JIA Shenli; LI Xingwen; SHI Zongqian; WANG Lijun

    2009-01-01

    The inlet and outlet pressure of the SF6 high voltage circuit-breaker nozzle are of importance in determining the thermal interruption capability of a breaker.Besides,electrode evaporation is inevitable during the arcing process,which may affect the SF6 arc behaviour significantly.In this study a numerical investigation on the arc characteristics of a supersonic nozzle is carried out,by considering the influence of the pressure ratio between the inlet and outlet,and the Cu vapour.It is demonstrated that a lower inlet pressure may result in a higher arc temperature,a lower arc voltage and a smaller mach number,and Cu vapour from electrode evaporation may cool the arc significantly.

  18. Experimental research on influence of emulsifier on crystallization quantity of emulsion explosives under dynamic pressure

    Institute of Scientific and Technical Information of China (English)

    HUANG Wen-yao; YAN Shi-long; WU Hong-bo; YUAN Sheng-fang

    2011-01-01

    Dynamic pressure was applied on emulsion explosive by using an underwater explosion measuring apparatus, and the crystallization quantity was measured by dissolution method after emulsion explosive was pressed; the influence of emulsi fier content and type was analyzed. The experimental results show that emulsifier content and type have an important effect on crystallization quantity of emulsion explosive. The crystallization quantity will reduce with Span-80 content from 2% to 4%, so the demulsification and crystallization will decrease if the emulsifier content improves appropriately and the dynamic pressure resistance will increase. For emulsion explosive emulsified by T-152 and Span-80, the crystallization quantity with T-152 is less than that of Span-80 under the same dynamic pressure. This shows that the emulsifying effect of T-152 is better than Span-80.

  19. Influence of fluid pore pressure on chaotic sliding of tectonic faults

    Science.gov (United States)

    Turuntaev, Sergey; Riga, Vasily

    2016-04-01

    The problem of permeable rock pore pressure variation influence on tectonic fault sliding and generation of seismic events was studied in the scope of rate-and-state friction model with two-parametric friction law. The coupled problem of pore-elasticity and fault sliding governed by two-parametric rate-and-state equation was studied numerically. The main modes of the fault sliding were found, and transitions from one mode to another due to the fluid pore pressure change were observed. The conditions for transition from stable to chaotic sliding (considered as an analog of seismic event generations) were found. It was shown, that chaotic sliding has features of Poincare stability and can be characterized by finite values of correlation integral and embedding dimension, which depend on critical shear stresses. Change of the effective critical stresses by the pore pressure variation will result in change of the tectonic fault sliding mode and consequently change of the seismic regime.

  20. Electrical Conductivity of Fine Crystalline Graphite under the Influence of the Hydrostatic Pressure

    Directory of Open Access Journals (Sweden)

    I.V. Ovsiienko

    2016-06-01

    Full Text Available It was investigated the influence of hydrostatic pressure on the electrical conductivity of crystalline graphite in temperature range (77-293 K. It was revealed that the reducing of electrical resistivity in specimens of fine crystalline graphite under the action of hydrostatic pressure is due to increasing of overlap between valence and conduction bands that leads to increase of the concentration of free charge carriers. The change of the overlap of valence and conduction bands was estimated. It is shown the decrease of the distance between the graphite layers under pressure is irreversible process, when load is remove the electric resistance increases slightly, but does not acquire the initial value.

  1. Influence of pore pressure to the development of a hydraulic fracture in poroelastic medium

    CERN Document Server

    Golovin, Sergey V

    2016-01-01

    In this paper we demonstrate the influence of the pore pressure to the development of a hydraulically-driven fracture in a poroelastic medium. We present a novel numerical model for propagation of a planar hydraulic fracture and prove its correctness by demonstration of the numerical convergence and by comparison with known solutions. The advantage of the algorithm is that it does not require the distinguishing of the fracture's tips and reconstruction of the numerical mesh according to the fracture propagation. Next, we perform a thorough analysis of the interplay of fluid filtration and redistribution of stresses near the fracture. We demonstrate that the fracture length decreases with the increase of the Biot's number (the parameter that determines the contribution of the pore pressure to the stress) and explain this effect by analysing the near-fracture pore pressure, rock deformation and stresses. We conclude, that the correct account for the fluid exchange between the fracture and the rock should be bas...

  2. Airway reconstruction in children

    Directory of Open Access Journals (Sweden)

    Rao Sanjay

    2009-01-01

    Full Text Available Aim/Background : Airway anomalies are infrequent but potentially life threatening in children. A program to care for these difficult children was set up at our institution, and this paper summarizes our experience. Methods: A total of 34 children were enrolled in the program over a period of three years. These children were evaluated as per the standard protocols. Treatment was individualized. Results: Of these 34 children, 28 had their airways restored and are doing well. Four children continue to remain on tracheostomy and two will require long term tracheostomy. There were two deaths. All children are under surveillance as there is a risk of recurrence. Conclusions: Airway anomalies are complex problems with significant morbidity and mortality. Current therapeutic modalities allow for good results. Most children were successfully decannulated and did well.

  3. Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure (letter)

    NARCIS (Netherlands)

    Wain, L.V.; Verwoert, G.C.; O'Reilly, P.F.; Shi, G.; Johnson, T.; Johnson, A.D.; Bochud, M.; Rice, K.M.; Henneman, P.; Smith, A.V.; Ehret, G.B.; Amin, N.; Larson, M.G.; Mooser, V.; Hadley, D.; Dorr, M.; Bis, J.C.; Aspelund, T.; Esko, T.; Janssens, A.C.J.W.; Zhao, J.H.; Heath, S.; Laan, M.; Fu, J.Y.; Pistis, G.; Luan, J.A.; Arora, P.; Lucas, G.; Pirastu, N.; Pichler, I.; Jackson, A.U.; Webster, R.J.; Zhang, F.; Peden, J.F.; Schmidt, H.; Tanaka, T.; Campbell, H.; Igl, W.; Milaneschi, Y.; Hottenga, J.J.; Vitart, V.; Chasman, D.I.; Trompet, S.; Bragg-Gresham, J.L.; Alizadeh, B.Z.; Chambers, J.C.; Guo, X.Q.; Lehtimaki, T.; Kuhnel, B.; Lopez, L.M.; Polasek, O.; Boban, M.; Nelson, C.P.; Morrison, A.C.; Pihur, V.; Ganesh, S.K.; Hofman, A.; Kundu, S.; Mattace-Raso, F.U.S.; Rivadeneira, F.; Sijbrands, E.J.G.; Uitterlinden, A.G.; Hwang, S.J.; Vasan, R.S.; Wang, T.J.; Bergmann, S.; Vollenweider, P.; Waeber, G.; Laitinen, J.; Pouta, A.; Zitting, P.; McArdle, W.L.; Kroemer, H.K.; Volker, U.; Volzke, H.; Glazer, N.L.; Taylor, K.D.; Harris, T.B.; Alavere, H.; Haller, T.; Keis, A.; Tammesoo, M.L.; Aulchenko, Y.; Barroso, I.; Khaw, K.T.; Galan, P.; Hercberg, S.; Lathrop, M.; Eyheramendy, S.; Org, E.; Sober, S.; Lu, X.W.; Nolte, I.M.; Penninx, B.W.; Corre, T.; Masciullo, C.; Sala, C.; Groop, L.; Voight, B.F.; Melander, O.; O'Donnell, C.J.; Salomaa, V.; d'Adamo, A.P.; Fabretto, A.; Faletra, F.; Ulivi, S.; Del Greco, M.F.; Facheris, M.; Collins, F.S.; Bergman, R.N.; Beilby, J.P.; Hung, J.; Musk, A.W.; Mangino, M.; Shin, S.Y.; Soranzo, N.; Watkins, H.; Goel, A.; Hamsten, A.; Gider, P.; Loitfelder, M.; Zeginigg, M.; Hernandez, D.; Najjar, S.S.; Navarro, P.; Wild, S.H.; Corsi, A.M.; Singleton, A.; de Geus, E.J.C.; Willemsen, G.; Parker, A.N.; Rose, L.M.; Buckley, B.; Stott, D.; Orru, M.; Uda, M.; van der Klauw, M.M.; Zhang, W.H.; Li, X.Z.; Scott, J.; Chen, Y.D.I.; Burke, G.L.; Kahonen, M.; Viikari, J.; Doring, A.; Meitinger, T.; Davies, G.; Starr, J.M.; Emilsson, V.; Plump, A.; Lindeman, J.H.; 'T Hoen, P.A.C.; Konig, I.R.; Felix, J.F.; Clarke, R.; Hopewell, J.C.; Ongen, H.; Breteler, M.; Debette, S.; DeStefano, A.L.; Fornage, M.; Mitchell, G.F.; Smith, N.L.; Holm, H.; Stefansson, K.; Thorleifsson, G.; Thorsteinsdottir, U.; Samani, N.J.; Preuss, M.; Rudan, I.; Hayward, C.; Deary, I.J.; Wichmann, H.E.; Raitakari, O.T.; Palmas, W.; Kooner, J.S.; Stolk, R.P.; Jukema, J.W.; Wright, A.F.; Boomsma, D.I.; Bandinelli, S.; Gyllensten, U.B.; Wilson, J.F.; Ferrucci, L.; Schmidt, R.; Farrall, M.; Spector, T.D.; Palmer, L.J.; Tuomilehto, J.; Pfeufer, A.; Gasparini, P.; Siscovick, D.; Altshuler, D.; Loos, R.J.F.; Toniolo, D.; Snieder, H.; Gieger, C.; Meneton, P.; Wareham, N.J.; Oostra, B.A.; Metspalu, A.; Launer, L.; Rettig, R.; Strachan, D.P.; Beckmann, J.S.; Witteman, J.C.M.; Erdmann, J.; van Dijk, K.W.; Boerwinkle, E.; Boehnke, M.; Ridker, P.M.; Jarvelin, M.R.; Chakravarti, A.; Abecasis, G.R.; Gudnason, V.; Newton-Cheh, C.; Levy, D.; Munroe, P.B.; Psaty, B.M.; Caulfield, M.J.; Rao, D.C.; Tobin, M.D.; Elliott, P.; van Duijn, C.M.

    2011-01-01

    Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans(1-3). We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we

  4. Influence of breastfeeding on maternal blood pressure at one month postpartum

    OpenAIRE

    Ebina S; Kashiwakura I

    2012-01-01

    Satoko Ebina,1 Ikuo Kashiwakura21Department of Disability and Health, 2Department of Radiological Life Sciences, Hirosaki University Graduate School of Health Sciences, Hirosaki, JapanBackground: The benefits of breastfeeding for improved health and developmental outcomes in mothers and their infants have been widely recognized. The purpose of the present study was to assess whether feeding modes influence maternal blood pressure at one month postpartum.Methods: The pregnancy charts of 407 wo...

  5. Paediatric airway management: basic aspects

    DEFF Research Database (Denmark)

    Holm-Knudsen, R J; Rasmussen, L S

    2009-01-01

    . Airway obstruction can be avoided by paying close attention to the positioning of the head of the child and by keeping the mouth of the child open during mask ventilation. The use of oral and nasopharyngeal airways, laryngeal mask airways, and cuffed endotracheal tubes is discussed with special reference...... to the circumstances in infants. A slightly different technique during laryngoscopy is suggested. The treatment of airway oedema and laryngospasm is described....

  6. Flow characteristics in the airways of a COPD patient with a saber-sheath trachea

    Science.gov (United States)

    Jin, Dohyun; Choi, Haecheon; Lee, Changhyun; Choi, Jiwoong; Kim, Kwanggi

    2016-11-01

    The chronic obstructive pulmonary disease (COPD) is a lung disease characterized by the irreversible airflow limitation caused by the damaged small airways and air sacs. Although COPD is not a disease of the trachea, many patients with COPD have saber-sheath tracheas. The effects of this morphological change in the trachea geometry on airflow are investigated in the present study. An unstructured finite volume method is used for the simulations during tidal breathing in normal and COPD airways, respectively. During inspiration, local large pressure drop is observed in the saber-sheath region of the COPD patient. During expiration, vortical structures are observed at the right main bronchus of the COPD airway, while the flow in the normal airway remains nearly laminar. High wall shear stress exists at convex regions of both airways during inspiration and expiration. However, due to the morphological changes in the COPD airway, relatively higher wall shear stress is observed in the patient airways.

  7. Humidified High Flow Nasal Cannula versus Nasal Continuous Positive Airway Pressure as an Initial Respiratory Support in Preterm Infants with Respiratory Distress: a Randomized, Controlled Non-Inferiority Trial.

    Science.gov (United States)

    Shin, Jeonghee; Park, Kyuhee; Lee, Eun Hee; Choi, Byung Min

    2017-04-01

    Heated, humidified, high-flow nasal cannula (HHFNC) is frequently used as a noninvasive respiratory support for preterm infants with respiratory distress. But there are limited studies that compares HHFNC with nasal continuous positive airway pressure (nCPAP) only as the initial treatment of respiratory distress in preterm infants immediately after birth. The aim of this study is to assess the effectiveness and safety of HHFNC compared to nCPAP for the initial treatment of preterm infants with respiratory distress. Preterm infants at between 30 and 35 weeks of gestational age were randomized to HHFNC or nCPAP when they showed respiratory distress in less than 24 hours of age postnatally. Preterm infants who needed invasive respiratory supports were excluded. Primary outcome was the incidence of treatment failure (defined as need for the intubation or mechanical ventilation). Eighty-five infants were analyzed. Sixteen of 42 infants randomized to HHFNC showed treatment failure compared to 9 of 43 infants using nCPAP (Risk difference 17.17 [-1.90-36.23]; P = 0.099). In terms of the reason for treatment failure, the frequency of hypoxia was significantly higher in the HHFNC group than in the nCPAP group (P = 0.020). There was no difference between the 2 groups in terms of respiratory and clinical outcomes and complications. Although HHFNC is safe compared to nCPAP, it is not certain that HHFNC is effective compared to nCPAP non-inferiorly as an initial respiratory support in preterm infants with respiratory distress.

  8. Oral appliance therapy versus nasal continuous positive airway pressure in obstructive sleep apnea syndrome: a randomized, placebo-controlled trial on self-reported symptoms of common sleep disorders and sleep-related problems.

    Science.gov (United States)

    Nikolopoulou, Maria; Byraki, Anna; Ahlberg, Jari; Heymans, Martijn W; Hamburger, H L; De Lange, Jan; Lobbezoo, Frank; Aarab, Ghizlane

    2017-03-10

    Obstructive sleep apnea syndrome (OSAS) is associated with several sleep disorders and sleep-related problems. Therefore, the aim of this study was to compare the effects of a mandibular advancement device (MAD) with those of nasal continuous positive airway pressure (nCPAP) on self-reported symptoms of common sleep disorders and sleep-related problems in mild and moderate OSAS patients. In this randomized placebo-controlled trial sixty-four OSAS patients (52.0± 9.6 years) were randomly assigned to an MAD, nCPAP or an intra-oral placebo appliance in a parallel design. All participants filled out the validated Dutch Sleep Disorders Questionnaire (SDQ) twice: one before treatment and one after six months of treatment. With 88 questions, thirteen scales were constructed, representing common sleep disorders and sleep-related problems. Linear mixed model analyses were performed to study differences between the groups for the different SDQ scales over time. The MAD group showed significant improvements over time in symptoms corresponding with "insomnia", "excessive daytime sleepiness", "psychiatric sleep disorder", "periodic limb movements", "sleep apnea", "sleep paralysis", "daytime dysfunction", "hypnagogic hallucinations/dreaming", "restless sleep", "negative conditioning", and "automatic behaviour" (range of P values: 0.000-0.014). These improvements in symptoms were, however, not significantly different from the improvements in symptoms observed in the nCPAP and placebo groups (range of P values: 0.090-0.897). It can be concluded that there is no significant difference between MAD and nCPAP in their positive effects on self-reported symptoms of common sleep disorders and sleep-related problems in mild and moderate OSAS patients. These beneficial effects may be a result of placebo effects. This article is protected by copyright. All rights reserved.

  9. Airway Clearance Devices for Cystic Fibrosis

    Science.gov (United States)

    2009-01-01

    Executive Summary Objective The purpose of this evidence-based analysis is to examine the safety and efficacy of airway clearance devices (ACDs) for cystic fibrosis and attempt to differentiate between devices, where possible, on grounds of clinical efficacy, quality of life, safety and/or patient preference. Background Cystic fibrosis (CF) is a common, inherited, life-limiting disease that affects multiple systems of the human body. Respiratory dysfunction is the primary complication and leading cause of death due to CF. CF causes abnormal mucus secretion in the airways, leading to airway obstruction and mucus plugging, which in turn can lead to bacterial infection and further mucous production. Over time, this almost cyclical process contributes to severe airway damage and loss of respiratory function. Removal of airway secretions, termed airway clearance, is thus an integral component of the management of CF. A variety of methods are available for airway clearance, some requiring mechanical devices, others physical manipulation of the body (e.g. physiotherapy). Conventional chest physiotherapy (CCPT), through the assistance of a caregiver, is the current standard of care for achieving airway clearance, particularly in young patients up to the ages of six or seven. CF patients are, however, living much longer now than in decades past. The median age of survival in Canada has risen to 37.0 years for the period of 1998-2002 (5-year window), up from 22.8 years for the 5-year window ending in 1977. The prevalence has also risen accordingly, last recorded as 3,453 in Canada in 2002, up from 1,630 in 1977. With individuals living longer, there is a greater need for independent methods of airway clearance. Airway Clearance Devices There are at least three classes of airway clearance devices: positive expiratory pressure devices (PEP), airway oscillating devices (AOD; either handheld or stationary) and high frequency chest compression (HFCC)/mechanical percussion (MP

  10. Influence of Resistance Training on Blood Pressure in Patients with Metabolic Syndrome and Menopause

    Directory of Open Access Journals (Sweden)

    Cardoso Glêbia Alexa

    2014-12-01

    Full Text Available This study investigated the chronic and acute influence of resistance exercise on blood pressure in women with metabolic syndrome before and after climacteric. Twenty sedentary women, nine non-menopausal (RNM and 11 menopausal (RM, performed training for 12 weeks. Meanwhile, 23 controls, 11 not menopausal (CNM and 12 menopausal (CM, remained sedentary. Blood pressure was measured before and after the training period in conditions of rest and after a session of exercise. Training promoted variations in blood pressure at rest from 116±13 to 118±10 mmHg (p=0.73 and from 128±12 mmHg to 120±11mmHg (p=0.12 in RNM and RM, respectively. CNM and CM varied from 115±11 to 116±12 mmHg (p=0.9 and from 115±14 mmHg to 116±13 mmHg (p=0.74. Blood pressure values in one acute session did not differ between groups (p>0.05. Resistance training did not improve blood pressure in women with metabolic syndrome, regardless of climacteric.

  11. Pathology influences blood pressure change following vagal stimulation in an animal intubation model.

    Directory of Open Access Journals (Sweden)

    Peter Jones

    Full Text Available PURPOSE: The haemodynamic response to critical care intubation is influenced by the use of sedation and relaxant drugs and the activation of the vagal reflex. It has been hypothesized that different disease states may have a contrasting effect on the cardiovascular response to vagal stimulation. Our objective was to determine whether the blood pressure response to vagal stimulation was modified by endotoxaemia or hypovolaemia. METHODS: New Zealand White rabbits were anaesthetised with urethane before tracheotomy. The exposed left Vagus nerve of randomised groups of control (n = 11, endotoxin (n = 11, 1 mg/kg, hypovolaemia 40% (n = 8 and hypovolaemia 20% (n = 8 rabbits were subjected to 10 Hz pulsed electrical stimulations of 25 s duration every 15 min. Haemodynamic parameters were recorded from a catheter in the right carotid artery connected to an iWorx monitor. Serum catecholamines were measured every 30 min using reverse-phase ion-pairing liquid chromatography. The change in blood pressure after vagal stimulation was compared to controls for one hour after the first death in the experimental groups. RESULTS: 29% of the rabbits died in the hypovolaemia 40% group and 27% in the endotoxin group. One rabbit died in the hypovolaemia 40% group before vagal stimulation and was excluded. Following electrical stimulation of the Vagus nerve there was a fall in blood pressure in control rabbits. Blood pressure was conserved in the hypovolaemic rabbits compared to controls (p<0.01. For the endotoxaemic rabbits, there was a non-significant trend for the mean blood pressure to decrease more than the controls. Serum catecholamines were significantly raised in both the hypovolaemic and endotoxaemic rabbits. CONCLUSIONS: Pathology may contribute to modifications in blood pressure when vagal activation occurs. Patients who are either already vasoconstricted, or not vasoplegic, may be less at risk from intubation-related vagally mediated

  12. Influence of cavity loss on an extrinsic Fabry-Perot cavity intensity-based pressure sensor.

    Science.gov (United States)

    Lű, Tao

    2015-09-01

    We present an extrinsic Fabry-Perot cavity intensity-based pressure sensor that mainly comprises a single-mode fiber end and an elastic monocrystalline silicon layer bonded to a silicon diaphragm. We investigated the influence of cavity loss on the performance indexes (PIS) of the intensity-based extrinsic Fabry-Perot cavity optical fiber pressure sensor. A buffer unit made of three incompressible oil cavities attenuated outside pressure and transformed pressure information into cavity length microchange information. Experimental results indicated that, under center quadrature-points within the linear regions of adjacent fringes, for an applied 40 kPa external pressure, cavity length was modulated by pressures of 69.9 kPa-109.9 kPa, 150.1 kPa-190 kPa, 220.1 kPa-259.9 kPa, and 279.9 kPa-319.9 kPa, output intensity ranges increased as 1 μW, 1.02 μW, 1.03 μW, and 1.05 μW, sensitivity increased as 0.01909 μW/kPa, 0.01986 μW/kPa, 0.02127 μW/kPa, and 0.02387 μW/kPa, but linearity degraded, as indicated by the standard deviation of linear fits of 0.02607, 0.02664, 0.02935, and 0.04879 due to cavity loss. Furthermore, the pressure ranges within the same quarter period decreased as 40 kPa, 37.45 kPa, 32.4 kPa, and 30.15 kPa. Consequently, the same lengths of linear regions within adjacent fringes of an approximately sinusoidal curve corresponded to different measurement ranges, linearities, and sensitivities. Initial cavity length must be chosen to optimize both signal strength and the PIS studied here in manufacturing this type sensor.

  13. Distinct PKA and Epac compartmentalization in airway function and plasticity

    NARCIS (Netherlands)

    Dekkers, Bart G. J.; Racke, Kurt; Schmidt, Martina

    2013-01-01

    Asthma and chronic obstructive pulmonary disease (COPD) are obstructive lung diseases characterized by airway obstruction, airway inflammation and airway remodelling. Next to inflammatory cells and airway epithelial cells, airway mesenchymal cells, including airway smooth muscle cells and (myo)fibro

  14. Social influences on young adults' alcohol consumption: norms, modeling, pressure, socializing, and conformity.

    Science.gov (United States)

    Oostveen, T; Knibbe, R; de Vries, H

    1996-01-01

    This study aims to assess which types of social influence are correlated with young people's (15-24 years) heavy drinking (six or more glasses) in public drinking places during the weekend. Drinking in public drinking places can be defined as a "timeout" situation. Therefore we assumed that situational factors (e.g., importance of socializing and direct pressures on drinking) would contribute more to the explained variance than variables indicating cognitive social influences (e.g., social norms and modeling). Stepwise regression analyses showed that in total 25% of the variance was explained by social norms of family and peers (15%), importance of socializing in drinking situations (7%), modeling (2%) and group size (1%). The results show that both a cognitive factor and a situational factor appear to be most strongly correlated with young people's frequency of heavy drinking in public drinking places. Within the category of situational influences those variables indicating direct social pressures were only weakly related or not significant. Studies focusing on measuring the impact of social influences may profit from including the concept of the importance of socializing and conformity as an additional factor.

  15. Severe upper airway obstruction during sleep.

    Science.gov (United States)

    Bonekat, H William; Hardin, Kimberly A

    2003-10-01

    Few disorders may manifest with predominantly sleep-related obstructive breathing. Obstructive sleep apnea (OSA) is a common disorder, varies in severity and is associated with significant cardiovascular and neurocognitive morbidity. It is estimated that between 8 and 18 million people in the United States have at least mild OSA. Although the exact mechanism of OSA is not well-delineated, multiple factors contribute to the development of upper airway obstruction and include anatomic, mechanical, neurologic, and inflammatory changes in the pharynx. OSA may occur concomitantly with asthma. Approximately 74% of asthmatics experience nocturnal symptoms of airflow obstruction secondary to reactive airways disease. Similar cytokine, chemokine, and histologic changes are seen in both disorders. Sleep deprivation, chronic upper airway edema, and inflammation associated with OSA may further exacerbate nocturnal asthma symptoms. Allergic rhinitis may contribute to both OSA and asthma. Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA. Treatment with CPAP therapy has also been shown to improve both daytime and nighttime peak expiratory flow rates in patients with concomitant OSA and asthma. It is important for allergists to be aware of how OSA may complicate diagnosis and treatment of asthma and allergic rhinitis. A thorough sleep history and high clinical suspicion for OSA is indicated, particularly in asthma patients who are refractory to standard medication treatments.

  16. Influence of CO{sup 2} on PVT properties of an oil crude at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Nilo Ricardo; Bonet, Euclides Jose [Centro de Estudos de Petroleo (CEPETRO/UNICAMP), SP (Brazil); Elias Junior, Antonio; Trevisan, Osvair Vidal [Universidade Estadual de Campinas (DEP/FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Engenharia de Petroleo

    2012-07-01

    The current oil frontier in Brazil is in Santos and Campos Basins, where huge oil accumulations were identified recently. Well tests have shown high values of pressure and concentration of carbon dioxide in these reservoirs. The characterization of the fluids existing in the pores of the reservoir rocks is a task for the exploitation of the hydrocarbons. The objective of this work is to present the experimental set up that was assembled to perform PVT analysis for oils at high pressure, moderate temperature and high CO{sub 2} content, oils analogous to that found in the new Brazilian pre-salt discoveries. Samples of dead oil and synthetic gas were received at the laboratory, where the recombination was carried out to obtain live oil, with twelve mole percent CO{sub 2}. The fluids were maintained inside special cylinders, with a floating piston, separating two compartments, one with the test fluid and the other with hydraulic fluid. Pressure was provided by a positive displacement pump connected to the bottles. The experiments achieved pressures up to 70 MPa at constant temperature, conditions expected for the reservoir. Starting at the high pressure, the fluid volume was increased by withdrawing the hydraulic fluid from the cylinder. Pressure and volume were recorded to determine the bubble point and compressibility of the system. The pressure drop continued until the mixture was in the two phase region, finishing the constant composition expansion process. After that, the sample was re-pressurized and the PVT bottle was agitated to reach the thermodynamic equilibrium, when the live oil was at single phase again. An aliquot of this mixture was transferred, keeping their pressure and temperature conditions, to a high pressure viscometer and to a densimeter. Another portion of live oil was flashed to a test tube and to a gasometer, to render the gas oil ratio. Afterwards, successive additions of carbon dioxide increased its concentration in live oil to 15, 20 and 35

  17. INFLUENCE OF SURFACTANT ON TWO-PHASE FLOW REGIME AND PRESSURE DROP IN UPWARD INCLINED PIPES

    Institute of Scientific and Technical Information of China (English)

    XIA Guo-dong; CHAI Lei

    2012-01-01

    The influence of a surfactant on the two-phase flow regime and the pressure drop in upward inclined pipes is investigated for various gas/liquid flow rates.The air/water and air/100 ppm sodium dodecyl sulphate aqueous solution are used as the working fluids.The influence of the surfactant on the two-phase flow regime in upward inclined pipes is investigated using the electrical tomographic technique.For 0°,2.5° and 5° pipe inclinations,the surfactant has obvious effect on the transition from the stratified wavy flow to the annular flow,and the range of the stratified smooth flow regime is also extended to higher gas velocities.For 10°pipe inclination,no stratified flow regime is observed in the air/water flow.In the air/surfactant solution system,however,the stratified flow regime can be found in the range of USG =10m/s-28m/s and USL =0.07 m/s-0.2 m/s.For all inclination angles,the changes of the pressure gradient characteristics are accompanied with the flow pattern transitions.Adding surfactant in a two-phase flow would reduce the pressure gradient significantly in the slug flow and annular flow regimes.In the annular flow regime,the pressure gradient gradually becomes free of the influence of the upward inclined angle,and is only dependent on the property of the two-phase flow.

  18. The influence of rowing-related postures upon respiratory muscle pressure and flow generating capacity.

    Science.gov (United States)

    Griffiths, Lisa A; McConnell, Alison K

    2012-12-01

    During the rowing stroke, the respiratory muscles are responsible for postural control, trunk stabilisation, generation/transmission of propulsive forces and ventilation (Bierstacker et al. in Int J Sports Med 7:73-79, 1986; Mahler et al. in Med Sci Sports Exerc 23:186-193, 1991). The challenge of these potentially competing requirements is exacerbated in certain parts of the rowing stroke due to flexed (stroke 'catch') and extended postures (stroke 'finish'). The purpose of this study was to assess the influence of the postural role of the trunk muscles upon pressure and flow generating capacity, by measuring maximal respiratory pressures, flows, and volumes in various seated postures relevant to rowing. Eleven male and five female participants took part in the study. Participants performed two separate testing sessions using two different testing protocols. Participants performed either maximal inspiratory or expiratory mouth pressure manoeuvres (Protocol 1), or maximal flow volume loops (MFVLs) (Protocol 2), whilst maintaining a variety of specified supported or unsupported static rowing-related postures. Starting lung volume was controlled by initiating the test breath in the upright position. Respiratory mouth pressures tended to be lower with recumbency, with a significant decrease in P (Emax) in unsupported recumbent postures (3-9 % compared to upright seated; P = 0.036). There was a significant decrease in function during dynamic manoeuvres, including PIF (5-9 %), FVC (4-7 %) and FEV(1) (4-6 %), in unsupported recumbent postures (p < 0.0125; Bonferroni corrected). Thus, respiratory pressure and flow generating capacity tended to decrease with recumbency; since lung volumes were standardised, this may have been, at least in part, influenced by the postural co-contraction of the trunk muscles.

  19. Influence of the external conditions on salt retention and pressure-induced electrical potential measured across a composite membrane

    DEFF Research Database (Denmark)

    Benavente, Juana; Jonsson, Gunnar Eigil

    1999-01-01

    Transport on single electrolyte solutions (NaCl and MgCl2) due to pressure gradients across a commercial reverse osmosis membrane was studied by measuring volume flux (J(v)), salt rejection (S) and pressure induced electrical potential (Delta E) in a crossflow cell. The influence on these paramet......Transport on single electrolyte solutions (NaCl and MgCl2) due to pressure gradients across a commercial reverse osmosis membrane was studied by measuring volume flux (J(v)), salt rejection (S) and pressure induced electrical potential (Delta E) in a crossflow cell. The influence...

  20. Advances in prehospital airway management.

    Science.gov (United States)

    Jacobs, Pe; Grabinsky, A

    2014-01-01

    Prehospital airway management is a key component of emergency responders and remains an important task of Emergency Medical Service (EMS) systems worldwide. The most advanced airway management techniques involving placement of oropharyngeal airways such as the Laryngeal Mask Airway or endotracheal tube. Endotracheal tube placement success is a common measure of out-of-hospital airway management quality. Regional variation in regard to training, education, and procedural exposure may be the major contributor to the findings in success and patient outcome. In studies demonstrating poor outcomes related to prehospital-attempted endotracheal intubation (ETI), both training and skill level of the provider are usually often low. Research supports a relationship between the number of intubation experiences and ETI success. National standards for certification of emergency medicine provider are in general too low to guarantee good success rate in emergency airway management by paramedics and physicians. Some paramedic training programs require more intense airway training above the national standard and some EMS systems in Europe staff their system with anesthesia providers instead. ETI remains the cornerstone of definitive prehospital airway management, However, ETI is not without risk and outcomes data remains controversial. Many systems may benefit from more input and guidance by the anesthesia department, which have higher volumes of airway management procedures and extensive training and experience not just with training of airway management but also with different airway management techniques and adjuncts.

  1. Parapharyngeal abscess following use of a laryngeal mask airway during open revision septorhinoplasty

    Directory of Open Access Journals (Sweden)

    Benjamin van der Woerd

    2015-01-01

    Conclusion: Laryngeal mask airways have a high rate of success and low rate of complications. In this reported case, pressure necrosis from over-inflation of the LMA is thought to have perforated the right pyriform fossa. The perforation created a communication into the parapharyngeal space causing infection. We report this case to highlight the importance of identifying possible complications associated with a routine method of airway management during shared airway surgeries.

  2. Study on the Influencing Factors of Blood Pressure Variability in Patients Undergoing Maintenance Hemodialysis

    Directory of Open Access Journals (Sweden)

    Xiao-hui BAI

    2016-09-01

    Full Text Available Objective: To investigate the influencing factors of blood pressure variability (BPV in patients with maintenance hemodialysis (MHD, so as to improve the patients’ prognosis.Methods: The clinical data of 107 MHD patients were retrospectively analyzed. According to intradialytic systolic pressure (SBP-BPV, the patients were assigned into high SBP-BPV group (n=52 and low SBP-BPV group (n=55. According to intradialytic diastolic pressure (DBP-BPV, they were divided into high DBP-BPV group (n=49 and low DBP-BPV group (n=58. The basic characteristics of patients in high and low SBP-BPV groups and DBP-BPV groups were compared, and the influencing factors of both SBP-BPV and DBP-BPV were also analyzed.Results: The differences were statistically significant between high and low SBP-BPV groups by comparison to the age, dry weight, body mass index (BMI, dialysis age, interdialysis weight gain (IDWG rate, pre-dialysis SBP, albumin (ALB, hemoglobin (Hb, total cholesterol (TC and calcium-phosphorus product (P<0.05 or P<0.01. The differences were also statistically significant between high and low DBP-BPV groups by comparison to the age, dry weight, BMI, IDWG rate, pre-dialysis SBP and DBP, Hb and calcium-phosphorus product (P<0.05 or P<0.01. Multiple linear regression analysis revealed that SBP-BPV was positively correlated with the age, IDWG rate and pre-dialysis SBP (P=0.002, P=0.001, P=0.006, while negatively with Hb (P=0.021. They were all regarded as independent influencing factors of SBP-BPV. Both IDWG rate and pre-dialysis DBP were positively correlated with DBP-BPV (P=0.019, P=0.004, and could be considered as independent influencing factors of DBP-BPV.Conclusion: Advanced age, increased IDWG%, pre-dialysis high SBP and decreased Hb are independent risk factors of SBP-BPV, and both increased IDWG rate and pre-dialysis high DBP are independent risk factors of DBP-BPV in intradialytic MHD patients. Pre-dialysis patients should positively control the

  3. On the influence of ram-pressure stripping on the star formation of simulated spiral galaxies

    CERN Document Server

    Kronberger, T; Ferrari, C; Unterguggenberger, S; Schindler, S

    2008-01-01

    We investigate the influence of ram-pressure stripping on the star formation and the mass distribution in simulated spiral galaxies. Special emphasis is put on the question where the newly formed stars are located. The stripping radius from the simulation is compared to analytical estimates. Disc galaxies are modelled in combined N-body/hydrodynamic simulations (GADGET-2) with prescriptions for cooling, star formation, stellar feedback, and galactic winds. These model galaxies move through a constant density and temperature gas, which has parameters comparable to the intra-cluster medium (ICM) in the outskirts of a galaxy cluster (T=3 keV ~3.6x10^7 K and rho=10^-28 g/cm^3). With this numerical setup we analyse the influence of ram-pressure stripping on the star formation rate of the model galaxy. We find that the star formation rate is significantly enhanced by the ram-pressure effect (up to a factor of 3). Stars form in the compressed central region of the galaxy as well as in the stripped gas behind the gal...

  4. An investigation of constant-pressure gas well testing influenced by high-velocity flow

    Energy Technology Data Exchange (ETDEWEB)

    Berumen, Sergio; Samaniego, Fernando; Cinco, Heber [PEMEX E and P and UNAM, Ciudad Universitaria, Coyoacan, Mexico (Mexico)

    1997-11-05

    This paper presents the results of a study of transient pressure analysis of gas flow under either constant bottom-hole pressure conditions or the constant wellhead pressure conditions. The effects of formation damage, wellbore storage and high-velocity flow are included in the model. The analysis of simulated well tests showed that the interpretation methods used for liquid flow are generally accurate when the m(p) is used. For these conditions, a graph of 1/q{sub D} vs. logt{sub D} presents gradually lower values of 1.1513 as the value of p{sub wf} decreases: for pressure buildup conditions, a graph of m{sub D}(1, {Delta}t{sub a{sub D}})/q{sub D}({Delta}t{sub a{sub D}}=0) vs. (t{sub a{sub D}}+{Delta}t{sub a{sub D}})/{Delta}t{sub a{sub D}} shows values of this slope within 1% of the 1.1513 value. However, when high-velocity flow influences constant pressure production tests, the slope can yield errors up to 13%. This upper limit occurs when the formation has a relatively `high` permeability (around 1 mD) and the rate performance test is affected by high-velocity flow. It was found that pressure buildup tests are superior to rate performance tests because high-velocity flow does not affect the slope of the straight line portion of the buildup curve. Derivative analysis of simulated buildup tests showed that the skin factor is considerably miscalculated when the high-velocity flow effect is significant. This problem could lead to errors in the calculation of the skin factor, s, up to 300%

  5. [Influence of treatment with olmesartan on ambulatory blood pressure monitoring parameters in patients with arterial hypertension].

    Science.gov (United States)

    Bregvadze, T R; Tseluĭko, V I; Mishchuk, N E

    2013-12-01

    Hypertension is the most common disease of the cardiovascular system. Active treatment of hypertension with adequate control of blood pressure (BP) can prevent complications, improve life quality and increase life expectancy. One of the interesting new antihypertensive agents, from the group of angiotensin receptor blockers is olmesartan. The obvious advantages of ambulatory blood pressure monitoring to traditional one-time measurements of BP make this method perspective for quality control of anti-hypertensive therapy. The aim of this study was to evaluate the influence of treatment with olmesartan on ambulatory blood pressure monitoring parameters in patients with hypertension. 38 out-patients with hypertension at the age of 25-84 years (mean 55,3±10,6) were studied. Patients received olmesartan 20 mg daily as monotherapy (20 patients (52,6%)) or in combination with other antihypertensive agents (18 patients (47,4%)). Treatment continued for 6 months. The complex examination included: measurement of office brachial BP, electrocardiography, echocardiography and ambulatory blood pressure monitoring (ABPM). As a result of treatment, office BP and diurnal BP, according to ABPM, significantly decreased; the favorable circadian BP profile dynamics were found: significantly less frequently observed lack of reduction in BP during night (daily index - non-dipper) - 18% vs. 64% (p treatment of hypertensive patients with olmesartan provides significant decline not only in office BP, but also in diurnal BP, normalizes BP of active and passive periods, also - daily index and reduces BP variability.

  6. Influence of thermal inhibitor position and temperature on vortex-shedding-driven pressure oscillations

    Institute of Scientific and Technical Information of China (English)

    Su Wanxing; Li Shipeng; Zhang Qiao; Li Junwei; Ye Qingqing; Wang Ningfei

    2013-01-01

    Vortex-acoustic coupling is one of the most important potential sources of combustion instability in solid rocket motors (SRMs).Based on the Von Karman Institute for Fluid Dynamics (VKI) experimental motor,the influence of the thermal inhibitor position and temperature on vortex-shedding-driven pressure oscillations is numerically studied via the large eddy simulation (LES)method.The simulation results demonstrate that vortex shedding is a periodic process and its accurate frequency can be numerically obtained.Acoustic modes could be easily excited by vortex shedding.The vortex shedding frequency and second acoustic frequency dominate the pressure oscillation characteristics in the chamber.Thermal inhibitor position and gas temperature have little effect on vortex shedding frequency,but have great impact on pressure oscillation amplitude.Pressure amplitude is much higher when the thermal inhibitor locates at the acoustic velocity anti-nodes.The farther the thermal inhibitor is to the nozzle head,the more vortex energy would be dissipated by the turbulence.Therefore,the vortex shedding amplitude at the second acoustic velocity antinode near 3/4L (L is chamber length) is larger than those of others.Besides,the natural acoustic frequencies increase with the gas temperature.As the vortex shedding frequency departs from the natural acoustic frequency,the vortex-acoustic feedback loop is decoupled.Consequently,both the vortex shedding and acoustic amplitudes decrease rapidly.

  7. Influence of External Pressure on the Performance of Quantum Dot Solar Cells.

    Science.gov (United States)

    Kim, Jaehoon; Jeong, Byeong Guk; Roh, Heebum; Song, Jiyun; Park, Myeongjin; Lee, Doh C; Bae, Wan Ki; Lee, Changhee

    2016-09-14

    We report the influence of post-treatment via the external pressure on the device performance of quantum dot (QD) solar cells. The structural analysis together with optical and electrical characterization on QD solids reveal that the external pressure compacts QD active layers by removing the mesoscopic voids and enhances the charge carrier transport along QD solids, leading to significant increase in JSC of QD solar cells. Increasing the external pressure, by contrast, accompanies reduction in FF and VOC, yielding the trade-off relationship among JSC and FF and VOC in PCE of devices. Optimization at the external pressure in the present study at 1.4-1.6 MPa enables us to achieve over 10% increase in PCE of QD solar cells. The approach and results show that the control over the organization of QDs is the key for the charge transport properties in ensemble and also offer simple yet effective mean to enhance the electrical performance of transistors and solar cells using QDs.

  8. Influence of Alignment Errors on Contact Pressure during Straight Bevel Gear Meshing Process

    Institute of Scientific and Technical Information of China (English)

    HAN Xinghui; HUA Lin; DENG Song; LUO Qiuping

    2015-01-01

    Straight bevel gears are widely applied in automotive, aerospace, chemical and many other fields as one of the most common type of gears. Currently, the researches on straight bevel gears have focused on the fields of fatigue, wear, noise and vibration, while little attention is paid to the effect of multiple alignment errors on the gear tooth wear. To study the influence of alignment errors on the gear tooth wear, a simulated model of a straight bevel gear pair is established. Then, the contact pressure on the tooth surface is analyzed under the various alignment errors according to the Archard wear relationship. The main combinations of alignment errors played vital roles on the tooth wear are investigated. The result shows that under the single alignment error, the contact pressure moves to the tooth heel and increases greatly at here whenDP=0.1 orDG=0.1; whenDE=–0.03, the contact pressure greatly increases at the tooth heel, but it obviously increases at the tooth toe whenDE=0.03; the alignment errorDγ=1 has little effect on the contact pressure on the tooth surface. Moreover, the combination ofDP,DG,DE<0 andDγ is the most dangerous type among the multiple alignment errors. This research provides valuable guidelines for predicting the tooth wear under various alignment errors.

  9. On the influence of ram-pressure stripping on interacting galaxies in clusters

    CERN Document Server

    Kapferer, W; Ferrari, C; Riser, T; Schindler, S

    2008-01-01

    We investigate the influence of ram pressure on the star-formation rate and the distribution of gas and stellar matter in interacting model galaxies in clusters. To simulate the baryonic and non-baryonic components of interacting disc galaxies moving through a hot, thin medium we use a combined N-body/hydrodynamic code GADGET2 with a description for star formation based on density thresholds. Two identical model spiral galaxies on a collision trajectory with three different configurations were investigated in detail. In the first configuration the galaxies collide without the presence of an ambient medium, in the second configurations the ram pressure acts face on on the interacting galaxies and in the third configuration the ram pressure acts edge on. The ambient medium is thin ($10^{-28}$ g/cm$^3$), hot (3 keV $\\approx 3.6\\times10^7$K) and has a relative velocity of 1000 km/s, to mimic an average low ram pressure in the outskirts of galaxy clusters. The interaction velocities are comparable to galaxy intera...

  10. ATMOSPHERIC PRESSURE AND ITS INFLUENCE ON TOURISTS AND TOURISM ACTIVITIES IN THE PRAHOVA CORRIDOR

    Directory of Open Access Journals (Sweden)

    HAVRIŞ LOREDANA-ELENA

    2014-03-01

    Full Text Available In the climate literature it is known that the atmospheric temperature directly and permanently acts on the all organisms and all geographical environment components, influencing the wellness of the weather sensitive persons and implicitly the wellness of tourists in this region. In the same time, its evolution is a good indicator in shaping the short and medium term meteorological forecast, considering that the region chosen for research is a very tripper one, especially during the winter season when the atmospheric pressure variation trend is much more pronounced. Within this framework, the present paper tries to develop a climatic diagnosis on the reference climate parameters (annual and monthly average pressure values, seasonal values, minimum and maximum absolute values and their emergence probability but also the non-periodic variability based on data recorded during 1961-2007 at Câmpina, Sinaia 1500, Predeal, Omu Peak and Braşov weather stations.

  11. Influence of pressure and temperature of deformation on phase composition of yttrium ceramics

    Science.gov (United States)

    Shishkova, N. V.; Malyshev, E. N.; Shepel, V. M.; Mikheenko, P. N.

    1994-07-01

    The influence of main flatting process parameters: pressure (P) and temperature (T), when obtaining conductors, on phase composition and critical properties of YBCO system ceramics placed into Al-bronze air-tight shell has been studied. It has been found that alongside with large decrease, due to plastic deformation, of the volume of superconducting (SC) phase there exist regions of the optimal combination of pressure and temperature where volume of SC phases can be ˜60...70% conserved as comparee to initial composition. The subsequent sintering of the deformed powder at 1250 K in the air-shell resulted in ˜90% restoring of the SC phase content. Zero resistance for different samples has been observed in the 80...86 K interval. Deformation scheme and power-temperature conditions as well as the material of hermetic shell used have shown the work to be perspective one in view of substitution of expensive silver for the Al-bronze.

  12. Influences of anisotropy and inhomogeneity on supporting pressure of tunnel face with kinematical approach

    Institute of Scientific and Technical Information of China (English)

    杨小礼; 李闻韬; 潘秋景

    2015-01-01

    Based on the active failure mechanism generated by a spatial discretization technique, the stability of tunnel face was studied. With the help of the spatial discretization technique, not only the anisotropy and inhomogeneity of the cohesion but also the inhomogeneity of the internal friction angle was taken into account in the analysis of the supporting forces. From the perspective of upper bound theorem, the upper bound solutions of supporting pressure were derived. The influence of the anisotropy and heterogeneity on the supporting forces as well as the failure mechanisms was discussed. The results show that the spatial discretization characteristics of cohesion and internal frictional angle impose a significant effect on the supporting pressure, which indicates that above factors should be considered in the actual engineering.

  13. The influence of high pressure on the properties of natural alumino-silicates

    Directory of Open Access Journals (Sweden)

    Šušić N.

    2002-01-01

    Full Text Available The effect of the application of high-pressure (up to 12 GPa on natural alumino-silicates has been studied. Chemical and mineral compositions and thermal behaviour have been analyzed of two samples of alumino-silicates. Results obtained indicate that the application of high pressure causes notable changes. A particularly significant one is the formation of amorphous phases on account of crystalline phases. An amorphous layer formed on particle surfaces with its diverse physical, mechanical, chemical, and other properties, especially over a long period of time, can influence the processes provoking or activating land slides or soil settlements. This enables derivation of many new materials with entirely new properties important for use in the ceramic and brick industries.

  14. Formwork pressure of self-consolidating concrete: Influence of flocculation mechanisms, structural rebuilding, thixotropy and rheology

    Science.gov (United States)

    Ferron, Raissa Patricia Douglas

    While self-consolidating concrete (SCC) may no longer be considered a "new concrete", there are still significant challenges to overcome before there is broader acceptance of SCC. One of these challenges concerns the formwork pressure exerted by SCC. A major advantage of SCC is the accelerated casting process due to the elimination of external vibration. However, faster casting rates may induce higher formwork pressure; this is a major concern for cast-in place applications, especially when casting tall elements. It has been reported that the formwork pressure of SCC can be less than hydrostatic pressure. This is due to the build-up of a three-dimensional structure when the concrete is left at rest. The development of this structure and the mechanisms behind it are of particular interest to users of SCC. The research presented in this manuscript was carried out at the Center for Advanced Cement-Based Materials at Northwestern University and the Universidad Complutense de Madrid. This dissertation focuses on the structural rebuilding SCC and its implications for formwork pressure. Special emphasis was given to the influence of flocculation mechanisms and the impact of material constituents. A rheological protocol to characterize structural rebuilding was developed. This protocol can be used to assess the contributions from irreversible structural build-up from hydration and reversible structural rebuilding from thixotropic effects. The impact of various mixture ingredients, including cement type, mineral admixtures, chemical admixtures and clays, on the structural rebuilding was examined. The results showed that the rheological properties of the paste matrix and its evolution over time can be used as an indication of the formwork pressure behavior. Formwork pressure is highly impacted by the structural rebuilding that occurs in the paste matrix, and the results showed that formwork pressure is related to the rate at which structural rebuilding occurs and the total

  15. Influence of the coupling between an atmospheric pressure ion mobility spectrometer and the low pressure ion inlet of a mass spectrometer on the mobility measurement

    Directory of Open Access Journals (Sweden)

    Gunzer Frank

    2016-01-01

    Full Text Available Ion mobility spectrometers (IMS are versatile gas analyzers. Due to their small size and robustness, combined with a very high sensitivity, they are often used in gas sensing applications such as environmental monitoring. In order to improve the selectivity, they are typically combined with a mass spectrometer (MS. Since IMS works at atmospheric pressure, and MS works at vacuum, a special interface reducing the pressure over normally two stages has to be used. In this paper the influence of this coupling of different pressure areas on the IMS signal will be analyzed with help of finite elements method simulations.

  16. Upper airway imaging and its role in preoperative airway evaluation

    Directory of Open Access Journals (Sweden)

    Jagadish G Sutagatti

    2016-01-01

    Full Text Available Ultrasonography (USG is well-known as a fast, safe, and noninvasive technique. Its application for imaging of the airway is now gaining momentum. The upper airway has a complex anatomy, and its assessment forms a vital part of every preanesthetic evaluation. Ultrasound (US imaging can help in upper airway assessment in the preoperative period. There are various approaches to upper airway USG. The technique has its own advantages, disadvantages, and limitations. This simple yet challenging imaging technique is all set to become an important part of routine preoperative airway evaluation. This article reviews the various approaches to upper airway US imaging, interpretation of the images, limitations, and disadvantages of the technique and its varied clinical applications in the preoperative period. The scientific material presented here was hand searched from textbooks and journals, electronically from PubMed, and Google scholar using text words.

  17. Relationship between airway pathophysiology and airway inflammation in older asthmatics

    DEFF Research Database (Denmark)

    Porsbjerg, Celeste M; Gibson, Peter G; Pretto, Jeffrey J;

    2013-01-01

    BACKGROUND AND OBJECTIVE: Asthma-related morbidity is greater in older compared with younger asthmatics. Airway closure is also greater in older asthmatics, an observation that may be explained by differences in airway inflammation. We hypothesized that in older adult patients with asthma......: Mean patient age was 67 years (confidence interval: 63-71) with a mean FEV1 of 78 % predicted (confidence interval: 70-85%). AHR correlated with sputum eosinophils (r = 0.68, P = 0.005) and eNO (r = 0.71, P ... or eNO. CONCLUSIONS: In older patients with asthma, airway inflammatory cells are linked to abnormal airway physiology. Eosinophilic airway inflammation is associated with AHR while neutrophilic inflammation may be an important determinant of airflow limitation at rest and airway closure during...

  18. Similar associations of parental prenatal smoking suggest child blood pressure is not influenced by intrauterine effects.

    Science.gov (United States)

    Brion, Marie-Jo A; Leary, Sam D; Smith, George Davey; Ness, Andy R

    2007-06-01

    Maternal smoking in pregnancy may be associated with higher offspring blood pressure; however, results of previous studies have been inconsistent and included varying confounder adjustments. We studied the association between maternal smoking in pregnancy and offspring blood pressure at 7 years in the Avon Longitudinal Study of Parents and Children, accounting for important social and environmental confounders and using partner smoking to investigate intrauterine effects. Analysis was carried out in 6509 children with maternal smoking data and 7149 children with partner smoking data. In models adjusting for child age and sex, modest differences in systolic blood pressure were observed between children of mothers who did and did not smoke during pregnancy (beta=0.64 mm Hg; 95% CI: 0.09 to 1.20; P=0.02). Adjusting for all of the confounders attenuated this difference toward the null (beta=0.05 mm Hg; 95% CI: -0.59 to 0.68; P=0.9), mostly because of adjustment for breastfeeding, maternal education, and family social class. Associations were similar between maternal and partner smoking with offspring systolic blood pressure (for partner smoking: beta=0.62 mm Hg; 95% CI: 0.17 to 1.07; P=0.07 minimally adjusted and beta=0.26 mm Hg; 95% CI: -0.36 to 0.87; P=0.4 fully adjusted), providing further evidence that differences in child blood pressure observed in minimally adjusted models are not because of a biological influence of maternal smoking on the intrauterine environment.

  19. Influence of dissociative recombination on the LTE of argon high-frequency plasmas at atmospheric pressure

    CERN Document Server

    Sainz, A; García, M C; Calzada, M D; Sainz, Abel; Margot, Joelle; Garcia, Maria Carmen; Calzada, Maria Dolores

    2004-01-01

    This work presents a few preliminary results from a collisional-radiative (CR) model intended to describe an argon microwave (2.45 GHz) plasma at atmospheric pressure. This model aims to investigate the influence of dissociative recombination products on the Saha-Boltzmann plasma equilibrium. The model is tested through comparison with experimental results obtained in an argon plasma column generated by a traveling electromagnetic surface-wave, which is suitable to perform a parametric investigation of the plasma. It is shown that dissociative recombination predominantly populates the 4s levels and the ground state. It is further observed that it strongly influences the population of the levels, specially those of lower energy. However, the higher levels (close to the ionization limit) appear to be in equilibrium whatever the plasma density. This allows assuming that the excitation temperature Texc determined from the upper levels in the atomic system in the Boltzmann-plot is equal to Te.

  20. Reliability and Validity of Self-rating Adverse Reaction Scale of Continuous Positive Airway Pressure among Patients with Obstructive Sleep Apnea Hypopnea Syndrome%阻塞性睡眠呼吸暂停低通气综合征患者持续正压通气治疗副作用自评量表的信度与效度研究

    Institute of Scientific and Technical Information of China (English)

    贾雯碧; 杨希; 曾继红; 余林

    2013-01-01

    目的:评价阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea hypopnea syndrome, OSAHS)患者持续正压通气(continuous positive airway pressure, CPAP)治疗副作用自评量表的信度与效度。方法根据相关文献和临床工作自制CPAP治疗副作用自评量表,采用内部一致性分析和重测信度法检测量表的信度;采用专家评议,选用副反应量表(Treatment Emergent Symptom Scale, TESS)、汉密尔顿焦虑量表(Hamilton Anxiety Scale, HAMA)、健康调查简表(the MOS 36-item Short-form Health Survey, SF-36)作为效标并结合因子分析法测量量表效度。结果量表内部一致性信度Cronbach’sα系数为0.825,重测信度为0.687;内容效度指数为0.870,量表与TESS、HAMA、SF-36显著相关(P0.4。结论 CPAP治疗副作用自评量表具有较好的信度与效度,可应用于OSAHS患者CPAP治疗副作用以及其对依从性影响的评估。%Objective To evaluate the reliability and validity of self-rating adverse reaction of continuous positive airway pressure (CPAP) scale among patients with obstructive sleep apnea hypopnea syndrome (OSAHS). Methods A self-rating adverse reaction of CPAP scale was developed based on literatures and clinical practice. The reliability of the scale was evaluated by internal consistency and test-retest reliability. Through expert review, taking Treatment Emergent Symptom Scale (TESS), Hamilton Anxiety Scale (HAMA) and the MOS 36-item Short-form Health Survey (SF-36) as criterion, the validity of the scale was evaluated with factor analysis. Results Cronbach’sαcoefficient was 0.825, ICC 0.687 and CVI 0.870. The scale was significantly related with TESS, HAMA and SF-36 (P<0.01) with the accumulative variance contribution rate of 77.271% and the load of every item on corresponding factor was higher than 0.4. Conclusion The self-rating adverse reaction of CPAP scale among OSAHS patients is with good reliability and

  1. The changes of cuff pressure in the endotracheal tube during laparoscopic surgery and influence on postoperative sore throat%妇科腹腔镜手术中气管导管套囊压力对患者术后咽喉痛的影响

    Institute of Scientific and Technical Information of China (English)

    胡静宜; 耿桂启; 李泓; 黄绍强

    2013-01-01

    Objective To investigate the changes of cuff pressure in the endotracheal tube during laparoscopic surgery and analyze the influence of cuff pressure on postoperative sore throat. Methods Fifty gynecologic patients receiving laparoscopic surgery(n=25) or open abdominal surgery (n=25) were recruited in this study. After anesthesia induction and tracheal intubation, the cuff pressure was set at 25 mmHg. The cuff pressure and airway pressure was recorded at 5 mins,15 mins,30 mins, 45rains and 60 mins after intubation. The patients' sore throat was measured at 2 hrs and 24 hrs after the surgery. Results The cuff pressure and airway pressure was stable during the surgery in patients receiving open abdominal surgery,while the cuff pressure and airway pressure was significantly increased during the surgery in patients receiving laparoscopic surgery. Moreover, there was positive correlation between the cuff pressure and airway pressure. The score of postoperative sore throat was significantly higher in the laparoscopic surgery group than in the open abdominal surgery group(P<0.01). Conclusion Pneumoperitoneum and the Trendelenburg position during laparoscopic surgery increase the airway pressure and cuff pressure, and may raise the incidence of postoperative sore throat.%目的 探讨妇科腹腔镜手术气管导管套囊压力变化,以及对术后咽喉痛的影响.方法 选择拟在气管插管全身麻醉下行腹腔镜手术或开腹手术的妇科患者各25例,进行全身麻醉诱导及气管插管后将套囊充气至25mmHg.分别于气管插管后5min、15min、30min、45min、60min记录套囊压力及气道峰压,于手术后2h及24h评估患者咽喉痛情况.结果 腹腔镜手术患者套囊压力及气道峰压在各时间点均明显增加.开腹手术患者气管插管后各时间点气管导管套囊压力及气道峰压未见明显变化.患者气管导管套囊压力与气道峰压具有显著相关性,同开腹手术患者相

  2. Integrated care pathways for airway diseases (AIRWAYS-ICPs)

    DEFF Research Database (Denmark)

    Bousquet, J; Addis, A; Adcock, I

    2014-01-01

    The objective of Integrated Care Pathways for Airway Diseases (AIRWAYS-ICPs) is to launch a collaboration to develop multi-sectoral care pathways for chronic respiratory diseases in European countries and regions. AIRWAYS-ICPs has strategic relevance to the European Union Health Strategy....... AIRWAYSICPs was initiated by Area 5 of the Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing. All stakeholders are involved (health and social care, patients, and policy makers)....

  3. Biomarkers in Airway Diseases

    Directory of Open Access Journals (Sweden)

    Janice M Leung

    2013-01-01

    Full Text Available The inherent limitations of spirometry and clinical history have prompted clinicians and scientists to search for surrogate markers of airway diseases. Although few biomarkers have been widely accepted into the clinical armamentarium, the authors explore three sources of biomarkers that have shown promise as indicators of disease severity and treatment response. In asthma, exhaled nitric oxide measurements can predict steroid responsiveness and sputum eosinophil counts have been used to titrate anti-inflammatory therapies. In chronic obstructive pulmonary disease, inflammatory plasma biomarkers, such as fibrinogen, club cell secretory protein-16 and surfactant protein D, can denote greater severity and predict the risk of exacerbations. While the multitude of disease phenotypes in respiratory medicine make biomarker development especially challenging, these three may soon play key roles in the diagnosis and management of airway diseases.

  4. 不同病因致急性呼吸衰竭患者行无创双水平气道正压通气治疗的临床价值探析%Clinical Value of Noninvasive Bi-level Positive Airway Pressure Ventilation in Patients With Acute Respiratory Failure Caused by Different Causes

    Institute of Scientific and Technical Information of China (English)

    李晓理

    2016-01-01

    目的:对不同病因致急性呼吸衰竭患者行无创双水平气道正压通气治疗的临床价值进行评价分析。方法对68例急性呼吸衰竭患者依据病因的不同分成心源性肺水肿组和重症肺炎组,接受无创双水平气道正压通气治疗,对比分析治疗效果。结果心源性肺水肿组患者治疗后动脉血气指标、症状缓解时间、治疗时间、住院时间与对照组比较差异有统计学意义(P <0.05)。结论无创双水平气道正压通气对不同病因引起的急性呼吸衰竭具有良好的治疗效果。%Objective The different causes in patients with acute respiratory failure and clinical value of noninvasive bi-level positive airway pressure ventilation in the treatment of evaluation and analysis. Methods 68 patients with acute respiratory failure were divided according to different causes of cardiogenic pulmonary edema and severe pneumonia group, accepted non-invasive bi-level positive airway pressure therapy, comparative analysis of the treatment effect. Results Cardiogenic pulmonary edema patients arterial blood gas treatment, remission time, treatment time, duration of hospitalization with the control group was significantly different (P<0.05). Conclusion Noninvasive bi-level positive airway pressure ventilation in acute respiratory failure caused by different causes have a good therapeutic effect.

  5. 节律性压力波对家犬气道黏蛋白分泌平衡的影响及其机制%Effect of rhythmic pressure waves on balancing airway basic mucus secretion in dogs

    Institute of Scientific and Technical Information of China (English)

    刘诗兰; 尤列·皮尔曼; 维克多·科罗索夫; 周向东

    2013-01-01

    目的:观察不同压力对家犬气道黏液层黏蛋白(MUC)分泌的影响,并初步探讨其参与机制。方法:24只健康家犬行双腔支气管导管插管,并随机分为4组(n=6)。A组家犬正常呼吸的频率及压力双侧通气(A1,A2);B组一侧不通气(B1),另一侧予以过量通气(B2);C组预先张力敏感性阳离子通道4(TRPV4)阻断剂钉红(RR)后按A组通气模式通气(C1,C2);D组预先TRPV4阻断剂RR处理后按B组通气模式通气(D1,D2)。通气12 h后,ELISA检测3组支气管灌洗液(BALF)中MUC(2,5AC和5B)蛋白含量;RT-PCR检测支气管肺组织匀浆中MUC(2,5AC和5B) mRNA转录水平。结果:与正常通气的A2组比较,过量通气的B2组家犬BALF中3种MUC蛋白含量显著升高,且以MUC5AC为主(P<0.05);与A1组比较,未通气的B1组则明显下降(P<0.05)。与A1,A2组比较,给予RR处理后的C1,C2组蛋白含量均明显降低(P<0.05)。与过量通气的B2组比较,给予TRPV4特异性阻断剂处理后再过量通气的D2组3种MUC蛋白含量亦明显下降(P<0.05)。与A2组比较过量通气的B2组肺组织MUC(2,5AC和5B) mRNA表达均明显上调(P<0.05);与A1,A2比较,给予RR处理后C1,C2组肺组织3种MUC mRNA转录水平显著下降(P<0.05);给予RR预处理后与B2组相比,D2组内MUC mRNA转录水平显著下调(P<0.05)。结论:节律性压力波参与维持家犬气道上皮黏液层黏蛋白分泌平衡调控,其机制主要通过TRPV4通道实现。%Objective:To investigate the effect of different pressure on mucin (MUC) secretion in dog airway mucus layer and explore the participation mechanisms. Methods:Totally 24 healthy dogs were randomly divided into 4 groups (n=6) after double-lumen endobronchial tube intubation. In group A the dogs were ventilated bilaterally with normal breathing frequency and pressure;In group B:one side of the dog lung did not ventilate, while the other side was excessively ventilated. In

  6. Infant flow biphasic nasal continuous positive airway pressure (BP- NCPAP vs. infant flow NCPAP for the facilitation of extubation in infants' ≤ 1,250 grams: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    O'Brien Karel

    2012-04-01

    Full Text Available Abstract Background The use of mechanical ventilation is associated with lung injury in preterm infants and therefore the goal is to avoid or minimize its use. To date there is very little consensus on what is considered the "best non-invasive ventilation mode" to be used post-extubation. The objective of this study was to compare the effectiveness of biphasic nasal continuous positive airway pressure (BP-NCPAP vs. NCPAP in facilitating sustained extubation in infants ≤ 1,250 grams. Methods We performed a randomized controlled trial of BP-NCPAP vs. NCPAP in infants ≤ 1,250 grams extubated for the first time following mechanical ventilation since birth. Infants were extubated using preset criteria or at the discretion of the attending neonatologist. The primary outcome was the incidence of sustained extubation for 7 days. Secondary outcomes included incidence of adverse events and short-term neonatal outcomes. Results Sixty-seven infants received BP-NCPAP and 69 NCPAP. Baseline characteristics were similar between groups. The trial was stopped early due to increased use of non-invasive ventilation from birth, falling short of our calculated sample size of 141 infants per group. The incidence of sustained extubation was not statistically different between the BP-NCPAP vs. NCPAP group (67% vs. 58%, P = 0.27. The incidence of adverse events and short-term neonatal outcomes were similar between the two groups (P > 0.05 except for retinopathy of prematurity which was noted to be higher (P = 0.02 in the BP-NCPAP group. Conclusions Biphasic NCPAP may be used to assist in weaning from mechanical ventilation. The effectiveness and safety of BP-NCPAP compared to NCPAP needs to be confirmed in a large multi-center trial as our study conclusions are limited by inadequate sample size. Clinical Trials Registration # NCT00308789 Source of support Grant # 06-06, Physicians Services Incorporated Foundation, Toronto, Canada. Summit technologies Inc. provided

  7. 早期联合应用NCPAP和PS治疗新生儿呼吸窘迫综合征%Early Nasal Continuous Positive Airway Pressure And Pulmonary Surfactant Therapy For Neonatal Respiratory Distress Syndrome

    Institute of Scientific and Technical Information of China (English)

    周媛; 杨静; 王岩岩; 王李敏

    2012-01-01

    目的 讨论经鼻持续气道正压通气(NCPAP)联合肺表面活性物质(PS)治疗新生儿呼吸窘迫综合征(NRDS)的治疗效果.方法 应用NCPAP联合PS治疗25例呼吸窘迫综合征的新生儿,并对其临床特点、动脉血气分析进行分析.结果 23例发绀和呼吸困难症状均有所减轻或消失.X线表现肺透亮度明显改善,或病变未进展,血气分析参数明显改善.2例因病情加重放弃治疗.结论 NCPAP联合PS能迅速有效地治疗新生儿呼吸窘迫综合征.用这种方法通过阻止呼吸窘迫综合征的进展,降低了以后应用呼吸机的需要.细致观察和正确的护理也是治疗成功的关键.%Objective To investigate the effects of nasal continuous positive airway pressure ( NCPAP ) early combined with pul-monary surfactant ( PS ) on newborn with respiratory distress syndrome ( RDS ). Methods 25 cases of newborn with respiratory distress syndrome were treated by Curosurf ( 100 ~ 200 mg/kg, every times ) and then they were given breath support by NCPAP. The clinical characteristics and results of blood gas analysis were evaluated. Results The symptoms of cyanosis and breathing difficulties disappeared or were reduced in 23 cases. The lung permeability showed by X-ray was obviously improved. Because the condition became more serious, two cases gave up. Conclusions Early NCPAP combined with PS have a good effect for newborn with respiratory distress syndrome, and improving the survival rate. It can decrease the requirement for respiratory machine by preventing respiratory distress syndrome. The cor-rect nursing is the key of successful treatment.

  8. Use of the i-gel™ supraglottic airway device in a patient with subglottic stenosis -a case report-.

    Science.gov (United States)

    Lee, Ki Hwa; Kang, Eun Su; Jung, Jae Wook; Park, Jae Hong; Choi, Young Gyun

    2013-09-01

    The airway management of patients with subglottic stenosis poses many challenges for the anesthesiologists. Many anesthesiologists use a narrow endotracheal tube for airway control. This, however, can lead to complications such as tracheal mucosal trauma, tracheal perforation or bleeding. The ASA difficult airway algorithm recommends the use of supraglottic airway devices in a failed intubation/ventilation scenario. In this report, we present a case of failed intubation in a patient with subglottic stenosis successfully managed during an i-gel™ supraglottic airway device. The device provided a good seal, and allowed for controlled mechanical ventilation with acceptable peak pressures while the patient was in the beach-chair position.

  9. Ultrasound of the airway

    Directory of Open Access Journals (Sweden)

    Pankaj Kundra

    2011-01-01

    Full Text Available Currently, the role of ultrasound (US in anaesthesia-related airway assessment and procedural interventions is encouraging, though it is still ill defined. US can visualise anatomical structures in the supraglottic, glottic and subglottic regions. The floor of the mouth can be visualised by both transcutaneous view of the neck and also by transoral or sublinguial views. However, imaging the epiglottis can be challenging as it is suspended in air. US may detect signs suggestive of difficult intubation, but the data are limited. Other possible applications in airway management include confirmation of correct endotracheal tube placement, prediction of post-extubation stridor, evaluation of soft tissue masses in the neck prior to intubation, assessment of subglottic diameter for determination of paediatric endotracheal tube size and percutaneous dilatational tracheostomy. With development of better probes, high-resolution imaging, real-time picture and clinical experience, US has become the potential first-line noninvasive airway assessment tool in anaesthesia and intensive care practice.

  10. The influence of revised high-heeled shoes on foot pressure and center of pressure during standing in young women.

    Science.gov (United States)

    Bae, Young-Hyeon; Ko, Mansoo; Lee, Suk Min

    2015-12-01

    [Purpose] Revised high-heeled shoes were developed to minimize foot deformities by reducing excessive load on the forefoot during walking or standing in adult females, who frequently wear standard high-heeled shoes. Specifically, this study aimed to investigate the effects of revised high-heeled shoes on foot pressure distribution and center of pressure distance during standing in adult females. [Subjects and Methods] Twelve healthy adult females were recruited to participate in this study. Foot pressures were obtained under 3 conditions: barefoot, in revised high-heeled shoes, and in standard 7-cm high-heeled shoes. Foot pressure was measured using the Tekscan HR mat scan system. One-way repeated analysis of variance was used to compare the foot pressure distribution and center of pressure distance under these 3 conditions. [Results] The center of pressure distance between the two lower limbs and the fore-rear distribution of foot pressure were significantly different for the 3 conditions. [Conclusion] Our findings support the premise that wearing revised high-heeled shoes seems to provide enhanced physiologic standing posture compared to wearing standard high-heeled shoes.

  11. 持续气道正压通气治疗重度阻塞型睡眠呼吸暂停综合征的探讨%Prediction of the Level of Continuous Positive Airway Pressure in the Managemert of Severe Obstrutive Sleep Apnea Syndrome

    Institute of Scientific and Technical Information of China (English)

    周建群; 郭兮恒; 胥振扬; 刘莉

    2002-01-01

    Objective To evaluate the effect of continuous positive airway pressure (CPAP) on the management ofsevere of obstructive sleep hypoxemia. Methods 25 patients with severe OSAS were enrolled in the study, the respiratorydisturbance index (RDI),the percentage of time spent at SaO2 below 90% (TS90),deoxygenation index (DOI) of both beforeand after the CPAP treatment. The actual level of CPAP (Pm) were calculated. Results RDI, TS90, DOI were improvedsignificantly after CPAP treatment, there was a close positive linear correlation between DOI and Pm. Conclusions It wassuggested that CPAP has a good effect on severe OSAS, DOI maybe valuable in predicting Pm in the management of severeOSAS.

  12. EEG reveals an early influence of social conformity on visual processing in group pressure situations.

    Science.gov (United States)

    Trautmann-Lengsfeld, Sina Alexa; Herrmann, Christoph Siegfried

    2013-01-01

    Humans are social beings and often have to perceive and perform within groups. In conflict situations, this puts them under pressure to either adhere to the group opinion or to risk controversy with the group. Psychological experiments have demonstrated that study participants adapt to erroneous group opinions in visual perception tasks, which they can easily solve correctly when performing on their own. Until this point, however, it is unclear whether this phenomenon of social conformity influences early stages of perception that might not even reach awareness or later stages of conscious decision-making. Using electroencephalography, this study has revealed that social conformity to the wrong group opinion resulted in a decrease of the posterior-lateral P1 in line with a decrease of the later centro-parietal P3. These results suggest that group pressure situations impact early unconscious visual perceptual processing, which results in a later diminished stimulus discrimination and an adaptation even to the wrong group opinion. These findings might have important implications for understanding social behavior in group settings and are discussed within the framework of social influence on eyewitness testimony.

  13. Influence of pressure gradient on streamwise skewness factor in turbulent boundary layer

    Science.gov (United States)

    Dróżdż, Artur

    2014-08-01

    The paper shows an effect of favourable and adverse pressure gradients on turbulent boundary layer. The skewness factor of streamwise velocity component was chosen as a measure of the pressure gradient impact. It appears that skewness factor is an indicator of convection velocity of coherent structures, which is not always equal to the average flow velocity. The analysis has been performed based upon velocity profiles measured with hot-wire technique in turbulent boundary layer with pressure gradient corresponding to turbomachinery conditions. The results show that the skewness factor decreases in the flow region subjected to FPG and increases in the APG conditions. The changes of convection velocity and skewness factor are caused by influence of large-scale motion through the mechanism called amplitude modulation. The large-scale motion is less active in FPG and more active in APG, therefore in FPG the production of vortices is random (there are no high and low speed regions), while in the APG the large-scale motion drives the production of vortices. Namely, the vortices appear only in the high-speed regions, therefore have convection velocity higher than local mean velocity. The convection velocity affects directly the turbulent sweep and ejection events. The more flow is dominated by large-scale motion the higher values takes both the convection velocity of small-scale structures and sweep events induced by them.

  14. Influence of patellofemoral pain syndrome on plantar pressure in the foot rollover process during gait

    Directory of Open Access Journals (Sweden)

    Sandra Aliberti

    2011-01-01

    Full Text Available BACKGROUND: Patellofemoral Pain Syndrome is one of the most common knee disorders among physically active young women. Despite its high incidence, the multifactorial etiology of this disorder is not fully understood. OBJECTIVES: To investigate the influence of Patellofemoral Pain Syndrome on plantar pressure distribution during the foot rollover process (i.e., the initial heel contact, midstance and propulsion phases of the gait. MATERIALS AND METHODS: Fifty-seven young adults, including 22 subjects with Patellofemoral Pain Syndrome (30 ± 7 years, 165 ± 9 cm, 63 ± 12 kg and 35 control subjects (29 ± 7 years, 164 ± 8 cm, 60 ± 11 kg, volunteered for the study. The contact area and peak pressure were evaluated using the Pedar-X system (Novel, Germany synchronized with ankle sagittal kinematics. RESULTS: Subjects with Patellofemoral Pain Syndrome showed a larger contact area over the medial (p = 0.004 and central (p = 0.002 rearfoot at the initial contact phase and a lower peak pressure over the medial forefoot (p = 0.033 during propulsion when compared with control subjects. CONCLUSIONS: Patellofemoral Pain Syndrome is related to a foot rollover pattern that is medially directed at the rearfoot during initial heel contact and laterally directed at the forefoot during propulsion. These detected alterations in the foot rollover process during gait may be used to develop clinical interventions using insoles, taping and therapeutic exercise to rehabilitate this dysfunction.

  15. Influence of an emulsifier on the pressure desensitization of emulsion explosives

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The desensitization degree of emulsion explosives (EE) was calculated with the peak pressure of explosion shock waves tested in water.To an explosive, the less the desensitization degree, the better the compression resistance, so the compression resistance of an explosive can be compared and analyzed quantificationally with the desensitization degree.The influence of an emulsifier on the pressure desensitization of EE was studied, including the content and category of emulsifiers.Three kinds of emulsifiers (Span-80,compound emulsifier, and T-152) were used in the tests.The experimental results show that both the content and category of emulsifiers make a great effect on the pressure desensitization of EE.The desensitization degree of EE reduces with the emulsifier content being increased, but there is an optimal content of an emulsifier for the compression resistance of EE.While the content of Span-80 reaches4wt%, the desensitization degree of EE becomes a minimal value, and augments somewhat if the emulsifier content is increased more.That is to say, the compression resistance of EE becomes the highest while the content of Span-80 is 4wt%, and the compression resistance will decline if the content of Span-80 is increased more.The compression resistance of the explosive emulsified by compound emulsifier is the highest among all the explosives, when the content of the whole components and manufacturing engineering are kept invariable.

  16. The predictable influence of soil temperature and barometric pressure changes on vapor intrusion

    Science.gov (United States)

    Barnes, David L.; McRae, Mary F.

    2017-02-01

    Intrusion of volatile organic compounds in the gas phase has impacted many buildings in many different locations. Various building and environmental factors such as buoyancy of heated air and changes in barometric pressure can influence indoor air concentrations due to vapor intrusion in these buildings resulting in seasonal and daily variability. One environmental factor that previous research has not adequately addressed is soil temperature. In this study we present two northern region study sites where the seasonal trends in indoor air VOC concentrations positively correlate with soil temperature, and short-term (days) variations are associated with barometric pressure changes. We present simple and multivariate linear relationships of indoor air concentrations as a function of soil temperature and barometric pressure. Results from this study show that small changes in soil temperature can result in relatively large changes in indoor air VOC concentrations where the gas phase VOCs are sourced from non-aqueous phase liquids contained in the soil. We use the results from this study to show that a five degree Celsius increase in soil temperature, a variation in soil temperature that is possible in many climatic regions, results in a two-fold increase in indoor air VOC concentrations. Additionally, analysis provides insight into how building ventilation, diffusion, and the relative rate of soil-gas flow across the slab both from the subsurface into the building and from the building into the subsurface impact short term variations in concentrations. With these results we are able to provide monitoring recommendations for practitioners.

  17. Research and Application of Influences of Lateral Pressure Coefficients on the Extension Angle of Coal Cracks

    Directory of Open Access Journals (Sweden)

    Cheng Liu

    2016-01-01

    Full Text Available Fluid-solid coupling seepage fields are ubiquitous in engineering practices. However, few investigations have been carried out on the rules of crack extension of solids under the effect of fluids. By using the RFPA2D (realistic failure process analysis in 2 dimensions, this research studied the influences of different lateral pressure coefficients on the extension direction and length of coal cracks. Also the result can be proved by fracture mechanics, stress intensity factor theory, and sliding crack theory. On this basis, aiming at a coal mine with the mining depth being over 700 m, the reliability of the above conclusion was further proved by testing the crustal stress at the positions with the buried depth varying from 750 m to 1,300 m. At the same time, in condition of meeting the water pressure required by the crack extension, permeability-increasing radius is selected preferably through AE energy index by simulation of hydraulic fracturing for coal seams under different lateral pressure coefficients, and the gas drainage achieves good effect in engineering practice.

  18. The influence of osmotic pressure on the lifespan of cellularly inspired energy-relevant materials

    Science.gov (United States)

    Kapania, Esha; Guillen, Katherine; Freeman, Eric; Philen, Michael

    2014-04-01

    Bimolecular unit cells have recently become a focus for biologically-inspired smart materials. This is largely due their ability to exhibit many of the same properties as the natural cell membrane. In this study, two lipid monolayers formed at a water/oil interface are brought together, creating a lipid bilayer at their interface with each droplet containing a different concentration of ions. This ionic concentration gradient leads to the development of a membrane potential across the bilayer as ions begin to passively diffuse across the membrane at varying rates, providing the proof of concept for energy storage through cellular mechanics. The focus of the study is to determine the influence of osmotic pressure on the lifespan of the lipid bilayer. We hypothesize that the greater osmotic pressure that develops from a greater ionic concentration gradient will prove to have a negative impact on the lifespan of the bilayer membrane, causing it to rupture sooner. This is due to the substantial amount of osmotic swelling that will occur to compensate for the ionic concentration gradient. This study will demonstrate how osmotic pressure will continue to be a limiting factor in the effectiveness and stability of cellularly-inspired energy relevant materials.

  19. Anticholinergic treatment in airways diseases.

    LENUS (Irish Health Repository)

    Flynn, Robert A

    2009-10-01

    The prevalence of chronic airways diseases such as chronic obstructive pulmonary disease and asthma is increasing. They lead to symptoms such as a cough and shortness of breath, partially through bronchoconstriction. Inhaled anticholinergics are one of a number of treatments designed to treat bronchoconstriction in airways disease. Both short-acting and long-acting agents are now available and this review highlights their efficacy and adverse event profile in chronic airways diseases.

  20. The Influence of Processing by Impulse Pressure on the Productivity of the Don Barley (Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    Pavlova Violetta Aleksandrovna

    2014-04-01

    Full Text Available Plant productivity is the important indicator, which determines the amount of yield. The productivity of plants depends on the number of bruchids per plant and on the weight of 1000 bruchids. The article studies the influence of impulse pressure of various magnitudes on plant productivity of Don barley (Hordeum vulgare L.. It was found that the pressure of 17 MPa was the most effective for increasing the productivity. Impulse pressure of other magnitudes also had influence on the productivity of Don barley.

  1. Airway epithelium is a predominant source of endogenous airway GABA and contributes to relaxation of airway smooth muscle tone

    OpenAIRE

    Gallos, George; Townsend, Elizabeth; Yim, Peter; Virag, Laszlo; Zhang, Yi; Xu, Dingbang; Bacchetta, Matthew; Emala, Charles W.

    2012-01-01

    Chronic obstructive pulmonary disease and asthma are characterized by hyperreactive airway responses that predispose patients to episodes of acute airway constriction. Recent studies suggest a complex paradigm of GABAergic signaling in airways that involves GABA-mediated relaxation of airway smooth muscle. However, the cellular source of airway GABA and mechanisms regulating its release remain unknown. We questioned whether epithelium is a major source of GABA in the airway and whether the ab...

  2. Experimental study on biopsy sampling using new flexible cryoprobes: influence of activation time, probe size, tissue consistency, and contact pressure of the probe on the size of the biopsy specimen.

    Science.gov (United States)

    Franke, Karl-Josef; Szyrach, Mara; Nilius, Georg; Hetzel, Jürgen; Hetzel, Martin; Ruehle, Karl-Heinz; Enderle, Markus D

    2009-08-01

    Cryoextraction is a procedure for recanalization of obstructed airways caused by exophytic growing tumors. Biopsy samples obtained with this method can be used for histological diagnosis. The objective of this study was to evaluate the parameters influencing the size of cryobiopsies in an in vitro animal model. New flexible cryoprobes with different diameters were used to extract biopsies from lung tissue. These biopsies were compared with forceps biopsy (gold standard) in terms of the biopsy size. Tissue dependency of the biopsy size was analyzed by comparing biopsies taken from the lung, the liver, and gastric mucosa. The effect of contact pressure exerted by the tip of the cryoprobe on the tissue was analyzed on liver tissue separately. Biopsy size was estimated by measuring the weight and the diameter. Weight and diameter of cryobiopsies correlated positively with longer activation times and larger diameters of the cryoprobe. The weight of the biopsies was tissue dependent: lung biopsy diameter. The biopsy size increased when the probe was pressed on the tissue during cooling. Cryobiopsies can be taken from different tissue types with flexible cryoprobes. The size of the samples depends on tissue type, probe diameter, application time, and pressure exerted by the probe on the tissue. Even the cryoprobe with the smallest diameter can provide larger biopsies than a forceps biopsy in lung. It can be expected that the same parameters influence the sample size of biopsies in vivo.

  3. THE INFLUENCE OF PRESSURE-DEPENDENT VISCOSITY ON THE THERMAL EVOLUTION OF SUPER-EARTHS

    Energy Technology Data Exchange (ETDEWEB)

    Stamenkovic, Vlada; Noack, Lena; Spohn, Tilman [Institute of Planetology, Westfaelische Wilhelms-Universitaet Muenster, Wilhelm-Klemm-Str. 10, 48149 Muenster (Germany); Breuer, Doris, E-mail: Vlada.Stamenkovic@dlr.de, E-mail: Lena.Noack@dlr.de, E-mail: Doris.Breuer@dlr.de, E-mail: Tilman.Spohn@dlr.de [Institute of Planetary Research, German Aerospace Center DLR, Rutherfordstrasse 2, 12489 Berlin (Germany)

    2012-03-20

    We study the thermal evolution of super-Earths with a one-dimensional (1D) parameterized convection model that has been adopted to account for a strong pressure dependence of the viscosity. A comparison with a 2D spherical convection model shows that the derived parameterization satisfactorily represents the main characteristics of the thermal evolution of massive rocky planets. We find that the pressure dependence of the viscosity strongly influences the thermal evolution of super-Earths-resulting in a highly sluggish convection regime in the lower mantles of those planets. Depending on the effective activation volume and for cooler initial conditions, we observe with growing planetary mass even the formation of a conductive lid above the core-mantle boundary (CMB), a so-called CMB-lid. For initially molten planets our results suggest no CMB-lids but instead a hot lower mantle and core as well as sluggish lower mantle convection. This implies that the initial interior temperatures, especially in the lower mantle, become crucial for the thermal evolution-the thermostat effect suggested to regulate the interior temperatures in terrestrial planets does not work for massive planets if the viscosity is strongly pressure dependent. The sluggish convection and the potential formation of the CMB-lid reduce the convective vigor throughout the mantle, thereby affecting convective stresses, lithospheric thicknesses, and heat fluxes. The pressure dependence of the viscosity may therefore also strongly affect the propensity of plate tectonics, volcanic activity, and the generation of a magnetic field of super-Earths.

  4. Influence of antibiotic pressure on bacterial bioluminescence, with emphasis on Staphylococcus aureus.

    Science.gov (United States)

    Daghighi, Seyedmojtaba; Sjollema, Jelmer; Harapanahalli, Akshay; Dijkstra, Rene J B; van der Mei, Henny C; Busscher, Henk J

    2015-12-01

    Bioluminescence imaging is used for longitudinal evaluation of bacteria in live animals. Clear relations exist between bacterial numbers and their bioluminescence. However, bioluminescence images of Staphylococcus aureus Xen29, S. aureus Xen36 and Escherichia coli Xen14 grown on tryptone soy agar in Etests demonstrated increased bioluminescence at sub-MICs of different antibiotics. This study aimed to further evaluate the influence of antibiotic pressure on bioluminescence in S. aureus Xen29. Bioluminescence of S. aureus Xen29, grown planktonically in tryptone soy broth, was quantified in the absence and presence of different concentrations of vancomycin, ciprofloxacin, erythromycin or chloramphenicol and was related to expression of the luxA gene under antibiotic pressure measured using real-time PCR. In the absence of antibiotics, staphylococcal bioluminescence increased over time until a maximum after ca. 6h of growth, and subsequently decreased to the detection threshold after 24h of growth owing to reduced bacterial metabolic activity. Up to MICs of the antibiotics, bioluminescence increased according to a similar pattern up to 6h of growth, but after 24h bioluminescence was higher than in the absence of antibiotics. Contrary to expectations, bioluminescence per organism (CFU) after different growth periods in the absence and at MICs of different antibiotics decreased with increasing expression of luxA. Summarising, antibiotic pressure impacts the relation between CFU and bioluminescence. Under antibiotic pressure, bioluminescence is not controlled by luxA expression but by co-factors impacting the bacterial metabolic activity. This conclusion is of utmost importance when evaluating antibiotic efficacy in live animals using bioluminescent bacterial strains.

  5. A THEORETICAL-MODEL FOR THE INFLUENCE OF GAS PROPERTIES AND PRESSURE ON SINGLE-BUBBLE FORMATION AT AN ORIFICE

    NARCIS (Netherlands)

    WILKINSON, PM; VANDIERENDONCK, LL

    1994-01-01

    A number of authors have on the basis of experiments determined that pressure and gas density can have an influence on bubble formation size. Usually this influence is attributed to the gas momentum force, generated by gas flowing into the bubble during its formation. In this article the theoretical

  6. Pharmacology of airway smooth muscle proliferation

    NARCIS (Netherlands)

    Gosens, Reinoud; Roscioni, Sara S.; Dekkers, Bart G. J.; Pera, Tonio; Schmidt, Martina; Schaafsma, Dedmer; Zaagsma, Johan; Meurs, Herman

    2008-01-01

    Airway smooth muscle thickening is a pathological feature that contributes significantly to airflow limitation and airway hyperresponsiveness in asthma. Ongoing research efforts aimed at identifying the mechanisms responsible for the increased airway smooth muscle mass have indicated that hyperplasi

  7. Cholinergic regulation of airway inflammation and remodelling

    NARCIS (Netherlands)

    Kolahian, Saeed; Gosens, Reinoud

    2012-01-01

    Acetylcholine is the predominant parasympathetic neurotransmitter in the airways that regulates bronchoconstriction and mucus secretion. Recent findings suggest that acetylcholine regulates additional functions in the airways, including inflammation and remodelling during inflammatory airway disease

  8. Inspecting the surface of implanted Si(111) during annealing by reflective second harmonic generation: The influence of chamber pressure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chung-Wei; Chang, Shoou-Jinn [Institute of Microelectronics and Department of Electrical Engineering and Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan (China); Liu, Chun-Chu [Department of Electrophysics, National Chia Yi University, Chia Yi 600, Taiwan (China); Lo, Kuang-Yao, E-mail: kuanglo@mail.ncyu.edu.tw [Department of Electrophysics, National Chia Yi University, Chia Yi 600, Taiwan (China); Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan (China)

    2013-02-01

    The present study used the reflective second harmonic generation (RSHG) method to analyze the quality of the surface layer of implanted Si(111) and to discuss the influence of chamber pressure during rapid thermal annealing. Under a lower chamber pressure, the recrystallization is better, and the defects are eliminated for a higher implanted dose because dopant phosphorus (P) atoms on the surface region more easily out-diffuse at lower chamber pressures. Thus, the occurrence of less out-diffusion makes more P atoms remain on the surface layer and causes larger defects, especially for higher implanted doses. Defects on the surface region are influenced by chamber pressure. In the current work, the RSHG results showed more detailed information by linking secondary ion mass spectrometry and sheet resistance measurement. - Highlights: ► Rapid thermal annealing (RTA) with different chamber pressures was performed. ► The quality of implanted Si was analyzed by reflective second harmonic generation. ► High-dose implanted Si is obviously influenced by the pressure in the RTA chamber. ► Pressure in the RTA chamber affects the generation of defects. ► Defect suppression is obvious at relatively low chamber pressure.

  9. 双水平呼吸道正压通气治疗重叠综合征的临床效果观察%Clinical observation of Bi-level positive airway pressure ventilation therapy treating overlap syndrome

    Institute of Scientific and Technical Information of China (English)

    刘晓丽; 刘芳勋; 张华; 刘芳; 牛志红; 黄秀清; 蒋延文

    2016-01-01

    Objective To discuss the therapeutic effect of Bi-Level positive airway pressure (Bi-PAP) ventilation therapy treating overlap syndrome.Methods Fifty patients with chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea hypopnea syndrome(OSAHS) from August 2013 to December 2014 in Beijing Shijitan Hospital,Capital Medical University were collected;according to the random number table method,all patients were divided into observation group and control group(25 cases in each group).The observation group was treated by Bi-PAP for 72 h and the control group was treated by continuous positive airway pressure (CPAP) for 72 h.pH value,arterial partial pressure of oxygen (PaO2),arterial partial pressure of carbon dioxide (PaCO2),arterial oxygen saturation (SaO2),serum C reactive protein (CRP) and tumor necrosis factor-α (TNF-α) levels before and after treatment in two groups were compared.After treatment,the apnea hypopnea index (AHI),the longest apnea duration,forced expiratory volume in one second (FEV1) and forced vital capacity(FVC) in two groups were compared.Results The pH value,PaO2,PaCO2,SaO2 had no statistical difference in two groups before treatment(P >0.05).After treatment,the pH value,PaO2 and SaO2 were significantly higher in observation group than those in control group;PaCO2 was significantly lower[(7.41 ±0.05) vs (7.31 ±0.04),(90 ±5)mmHg vs (76 ± 7) mmHg,(98.3 ± 1.2) % vs (95.7 ± 1.6) %,(45 ± 6) mmHg vs (57 ± 8) mmHg,P < 0.05].Serum CRP and TNF-α levels did not show significant difference before treatment in 2 groups(P >0.05);after treatment,those in the observation group were significantly lower than those of the control group[(4.9 ± 1.2) mg/L vs (7.6 ±1.1) mg/L,(44 ± 8) ng/L vs (53 ± 6) ng/L,P < 0.05].Mter treatment,the AHI and the longest apnea duration in observation group were significantly lower than those of the control group[(7.2 ±2.9) vs (15.6 ±3.2),(10 ±4)s vs (16 ±5)s,P <0.05].After treatment

  10. 改良Proseal喉罩与改良普通喉罩在无痛纤维支气管镜检查中的气道管理%Comparison of modified Proseal laryngeal mask and three-way laryngeal mask airway for painless fiberoptic bronchoscopy in airway management in effect

    Institute of Scientific and Technical Information of China (English)

    王绍林; 张进; 张鹏; 殷骏; 俞蕾; 何磊; 程庆余; 刘小彬

    2012-01-01

    Objective To compare the effects of airway management with modified Proseal laryngeal mask airway and modified laryngeal mask airway in painless fiberoptic bronchoscopy. Methods Forty patients who scheduled for painless fiheroptic bronechscopy were randomly divided into two groups (n = 20): Modified Proseal laryngeal mask airway group (group P) and modified laryngeal mask airway group (group L). After induction of general anesthesia were inserted with hands. BP, HR and SpO2 were measured respectively before anesthesia laryngeal mask airway (To), immediately after inserting laryngeal mask airway (T1 ) and 3 min (T2). The laryngeal mask airway insertion time, complications, the ventilated assessment, fiberoptic bronchoscopy assessed and airway sealing pressure were also simultaneously recorded. Results There was no significant difference in laryngeal mask airway insertion time, BP. HR and SpO2 at each point Airway sealing pressure in group P was significantly higher than that in group L (P<0. 01). The excellent rates of ventilated assessment and fiberoptic bronchoscopy scores were both 100% in group P, and were much higher than those in group L (85%, 80% respectively F<0. 01). Blood staining in group P was less than that in group L (1 vs. 7 cases, respectively P<0. 05). Conclusion The modified Proseal laryngeal mask is better than modified laryngeal mask airway at the aspects of gas-tightness, assessment of ventilation and fiberoptic bronchoscopy. but no effects on hemodynamics in two groups.Objective To compare the effects of airway management with modified Proseal laryngeal mask airway and modified laryngeal mask airway in painless fiberoptic bronchoscopy. Methods Forty patients who scheduled for painless fiheroptic bronechscopy were randomly divided into two groups (n = 20): Modified Proseal laryngeal mask airway group (group P) and modified laryngeal mask airway group (group L). After induction of general anesthesia were inserted with hands. BP, HR and SpO2 were

  11. Influence of temperature and pressure on quartz-water-CO₂ contact angle and CO₂-water interfacial tension.

    Science.gov (United States)

    Sarmadivaleh, Mohammad; Al-Yaseri, Ahmed Z; Iglauer, Stefan

    2015-03-01

    We measured water-CO2 contact angles on a smooth quartz surface (RMS surface roughness ∼40 nm) as a function of pressure and temperature. The advancing water contact angle θ was 0° at 0.1 MPa CO2 pressure and all temperatures tested (296-343 K); θ increased significantly with increasing pressure and temperature (θ=35° at 296 K and θ=56° at 343 K at 20 MPa). A larger θ implies less structural and residual trapping and thus lower CO2 storage capacities at higher pressures and temperatures. Furthermore we did not identify any significant influence of CO2-water equilibration on θ. Moreover, we measured the CO2-water interfacial tension γ and found that γ strongly decreased with increasing pressure up to ∼10 MPa, and then decreased with a smaller slope with further increasing pressure. γ also increased with increasing temperature.

  12. Hydroformylation of Cyclohexene with Carbon Dioxide and Hydrogen Using Ruthenium Carbonyl Catalyst: Influence of Pressures of Gaseous Components

    Directory of Open Access Journals (Sweden)

    Masahiko Arai

    2007-08-01

    Full Text Available Hydroformylation of cyclohexene was studied with a catalyst system ofRu3(CO12 and LiCl using H2 and CO2 instead of CO in NMP. The influence of H2 andCO2 pressures on the total conversion and the product distribution was examined. It wasshown that increasing total pressure of H2 and CO2 promoted the reverse water gas shiftreaction and increased the yield of cyclohexanecarboxaldehyde. Its hydrogenation tocyclohexanemethanol was promoted with increasing H2 pressure but suppressed withincreasing CO2 pressure. Cyclohexane was also formed along with those products and thisdirect hydrogenation was suppressed with increasing CO2 pressure. The roles of CO2 as apromoter as well as a reactant were further examined by phase behavior observations andhigh pressure FTIR measurements.

  13. Clinical value of upper airway pressure measurement and Friedman staging system in preoperative evaluation for obstructive sleep apnea hypopnea syndrome%上气道测压与Friedman分型在上气道阻塞平面判断中的相关性研究

    Institute of Scientific and Technical Information of China (English)

    田旭; 李五一; 霍红; 余蓉; 王剑

    2011-01-01

    Objective To evaluate the clinical value of localization of upper airway obstructive site with pressure measurements and Friedman staging system in preoperative upper airway reconstructive surgery for obstructive sleep apnea-hypopnea syndrome (OSAHS), and to evaluate the value of Friedman staging system in predicting the upper airway obstructive site. Methods One hundred and three patients with snoring, daytime sleepiness diagnosed as OSAHS by polysomnography were first classified using Friedman staging system, and then examined using whole night recording, including airway continuous pressure measurements (Apnea Graph, AG). AG transducer catheter containing two pressure and two temperature sensors used for obstruction site determination and detection of apnea events during sleep. Obstructive sites were divided into upper (retropalatal region) or lower level (retroglossal region). Using constituent ratio to reflect the obstructive proportion of different levels so as to find the correlation between Friedman staging system and localization of upper airway obstructive site with pressure measurements performed during sleep,and to evaluate the clinical value of Friedman staging system in predicting the severity of OSAHS. Results There was statistically significant difference in the constituent ratio of retroglossal obstruction determined by AG, according to Friedman staging system, Friedman tongue position (FTP) and tonsil size grading ( F =13. 876, 7. 655,10. 207 respectively, P <0. 05 ). The constituent ratio of retroglossal obstruction between stage Ⅳ and Ⅰ , Ⅱ, Ⅲ(P<0.01) was significantly different. With the increasing of Friedman staging,the constituent ratio of retroglossal obstruction had the tendency of increasing. The constituent ratio of retroglossal obstruction between FTP grade 2 and grade 3, grade 4 ( P < 0. 05 ) was significantly different.With the increasing of FTP grading, the constituent ratio of retroglossal obstruction had the tendency

  14. The Tax Pressure Influence on Underground Economy Size in Romania between 2001-2010

    Directory of Open Access Journals (Sweden)

    Rodica PRIPOAIE

    2011-11-01

    Full Text Available The aggressive extension of the level of underground economy, with a more and more organized developmental character, tends to place the phenomenon as a direct threat to the proper operation of State democratic institutions and, due to the generalized internationalization trend of the phenomenon, quantification and control of underground economy constitutes a problem considered by national governments and international bodies as well. The obvious growth and refinement trends of the methods used by the „practicants” of underground activities impose the need to know and to evaluate this phenomenon, to establish the possibe reaction ways of the public power, according to the cost and consequences forecast on the short term and, especially, on the long term, of the adopted measures. It is therefore necessary to analyze all pertinent factors that influence the level and structure of the underground economy and particularly the fiscal pressure.

  15. Viscosity bio reducer Influence in a non-Newtonian fluid horizontal pipeline pressure gradient

    Directory of Open Access Journals (Sweden)

    Edgardo Jonathan Suarez-Dominguez

    2014-03-01

    Full Text Available Due to increased production of heavy and extra heavy crude in Mexico, it has led to the necessity touse chemicals to facilitate the transport in the pipe of our country. Experimental study was conductedto analyze the influence of a viscosity reducer of biological origin (BRV, on the rheological behaviorof heavy oil in the northern region of Mexico, finding that it exhibits a non-Newtonian viscoelasticbehavior, where a concentration increase of BRV leads to a consistency decrease and an increasedflow order, where dilatant behavior was observed in high temperatures. From these results it wasestimated the pressure losses by friction in a horizontal pipe for single phase and two phase flow. Wefound that in all cases the increase in the concentration of BRV reduces these losses.

  16. Role of laryngeal mask airway in laparoscopic cholecystectomy

    Institute of Scientific and Technical Information of China (English)

    José; M; Bele?a; Ernesto; Josué; Ochoa; Mónica; Nú?ez; Carlos; Gilsanz; Alfonso; Vidal

    2015-01-01

    Laparoscopic cholecystectomy is one of the most commonly performed surgical procedures and the laryngeal mask airway(LMA) is the most common supraglottic airway device used by the anesthesiologists to manage airway during general anesthesia. Use of LMA has some advantages when compared to endotracheal intubation, such as quick and ease of placement, a lesser requirement for neuromuscular blockade and a lower incidence of postoperative morbididy. However, the use of the LMA in laparoscopy is controversial, based on a concern about increased risk of regurgitation and pulmonary aspiration. The ability of these devices to provide optimal ventilation during laparoscopic procedures has been also questioned. The most important parameter to secure an adequate ventilation and oxygenation for the LMA under pneumoperitoneum condition is its seal pressure of airway. A good sealing pressure, not only state correct patient ventilation, but it reduces the potential risk of aspiration due to the better seal of airway. In addition, the LMAs incorporating a gastric access, permitting a safe anesthesia based on these commented points. We did a literature search to clarify if the use of LMA in preference to intubation provides inadequate ventilation or increase the risk of aspiration in patients undergoing laparoscopic cholecystectomy. We found evidence stating that LMA with drain channel achieves adequate ventilation for these procedures. Limited evidence was found to consider these devices completely safe against aspiration. However, we observed that the incidence of regurgitation and aspiration associated with the use of the LMA in laparoscopic surgery is very low.

  17. Batch cooling crystallization and pressure filtration of sulphathiazole: the influence of solvent composition.

    Science.gov (United States)

    Häkkinen, Antti; Pöllänen, Kati; Karjalainen, Milja; Rantanen, Jukka; Louhi-Kultanen, Marjatta; Nyström, Lars

    2005-02-01

    Currently there is a great interest in new process analytical approaches to increase the process understanding of pharmaceutical unit operations. In the present study, the influence of the solvent composition on the material properties and, further, on the filtration characteristics, of different crystal suspensions obtained through an unseeded batch-cooling-crystallization process was studied. Sulphathiazole, which is an antibiotic agent with multiple polymorphic forms, was produced by performing laboratory-scale cooling crystallization experiments from five different mixtures of water and propan-1-ol (n-propanol). The size, shape and polymorphic composition of the crystals produced were characterized with a scanning electron microscope, with a novel automated image analyser and with an X-ray powder diffractometer. All of the monitored crystal properties were found to clearly differ between the samples obtained from different solvents. The crystals produced in the batch-cooling-crystallization experiments were separated from the crystallizing solvents using a batch-type pressure Nutsche filter, and the filtration characteristics of the suspensions were evaluated on the basis of average filter-cake porosities and average specific cake resistances, which were determined from the experimentally obtained filtration data. Comparison between the calculated filtration characteristics revealed that considerable differences existed between the different suspensions, and it could therefore be concluded that the pressure-filtration process was influenced by the composition of the crystallizing solvent. The filterability of all the studied sulphathiazole suspensions was considered to be rather good on the basis of the relatively low cake porosities (0.51-0.63), which were accompanied with low average specific cake resistances [(8.7 x 10(7))-(1.2 x 10(9)) m/kg].

  18. Sildenafil does not influence hepatic venous pressure gradient in patients with cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Jens Otto Clemmesen; Annamaria Giraldi; Peter Ott; Kim Dalhoff; Bent Adel Hansen; Fin Stolze Larsen

    2008-01-01

    AIM: To investigate if sildenafil increases splanchnic blood flow and changes the hepatic venous pressure gradient (HVPG) in patients with cirrhosis. Phosphodiesterase type-5 inhibitors are valuable in the treatment of erectile dysfunction and pulmonary hypertension in patients with end-stage liver disease. However, the effect of phosphodiesterase type-5 inhibitors on splanchnic blood flow and portal hypertension remains essentially unknown. METHODS: Ten patients with biopsy proven cirrhosis (five females/five males, mean age 54±8 years) and an HVPG above 12 mmHg were studied after informed consent. Measurement of splanchnic blood flow and the HVPG during liver vein catheterization were done before and 80 min after oral administration of 50 mg sildenafil. Blood flow was estimated by use of indocyanine green clearance technique and Fick's principle, with correction for non-steady state. RESULTS: The plasma concentration of sildenafil was 222±136 ng/mL 80 min after administration. Mean arterial blood pressure decreased from 77±7 mmHg to 66±12 mmHg, P=0.003, while the splanchnic blood flow and oxygen consumption remained unchanged at 1.14±0.71 L/min and 2.3±0.6 mmol/ min, respectively. Also the HVPG remained unchanged (18±2 mmHg vs 16±2 mmHg) with individual changes ranging from-8 mmHg to+2 mmHg. In seven patients, HVPG decreased and in three it increased. CONCLUSION: In spite of arterial blood pressure decreases 80 min after administration of the phosphodiesterase type-5 inhibitor sildenafil, the present study could not demonstrate any clinical relevant influence on splanichnic blood flow, oxygen consumption or the HVPG.

  19. Influence of dynamic pressure on deep underground soft rock roadway support and its application

    Institute of Scientific and Technical Information of China (English)

    Meng Qingbin; Han Lijun; Chen Yanlong; Fan Jiadong; Wen Shengyong; Yu Liyuan; Li Hao

    2016-01-01

    Due to high ground stress and mining disturbance, the deformation and failure of deep soft rock roadway is serious, and invalidation of the anchor net-anchor cable supporting structure occurs. The failure char-acteristics of roadways revealed with the help of the ground pressure monitoring. Theoretical analysis was adopted to analyze the influence of mining disturbance on stress distribution in surrounding rock, and the change of stress was also calculated. Considering the change of stress in surrounding rock of bot-tom extraction roadway, the displacement, plastic zone and distribution law of principal stress difference under different support schemes were studied by means of FLAC3D. The supporting scheme of U-shaped steel was proposed for bottom extraction roadway that underwent mining disturbance. We carried out a similarity model test to verify the effect of support in dynamic pressure. Monitoring results demonstrated the change rules of deformation and stress of surrounding rock in different supporting schemes. The supporting scheme of U-shaped steel had an effective control on deformation of surrounding rock. The scheme was successfully applied in underground engineering practice, and achieved good technical and economic benefits.

  20. Influence of gas pressure and substrate temperature on PIII nitrocarburizing process of AISI 304 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Abd El-Rahman, A.M. [Physics Department, Faculty of Science, South Valley University, Sohag Branch, Sohag (Egypt) and Institute of Ion Beam Physics and Material Research, FWII, Forschungszentrum Rossendorf, 01314 Dresden (Germany)]. E-mail: ahmedphys96@hotmail.com; El-Hossary, F.M. [Physics Department, Faculty of Science, South Valley University, Sohag Branch, Sohag (Egypt); Negm, N.Z. [Physics Department, Faculty of Science, South Valley University, Sohag Branch, Sohag (Egypt); Prokert, F. [Institute of Ion Beam Physics and Material Research, FWII, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Richter, E. [Institute of Ion Beam Physics and Material Research, FWII, Forschungszentrum Rossendorf, 01314 Dresden (Germany); Moeller, W. [Institute of Ion Beam Physics and Material Research, FWII, Forschungszentrum Rossendorf, 01314 Dresden (Germany)

    2004-12-01

    Plasma immersion ion implantation (PIII) has been used to modify the surface properties of 304 austenitic stainless steel (AISI). The influence of working gas pressure, 0.2-1.0 Pa, and substrate temperature, 300-500 deg. C, on the microstructure, treating rate, nitrogen/carbon concentration depth profile, and surface microhardness was investigated. A gas composition of 25% C{sub 2}H{sub 2}, 75% N{sub 2}, r.f. plasma power input of 350 W, and a negatively biased potential of 30 kV were fixed during the experiment. The experimental results show that the substrate temperature and the diffusion process of nitrogen and carbon depend on the gas pressure inside the plasma chamber. The thickness of the modified layer has been found to be more than 30 {mu}m for samples were treated in the plasma for 60 min. The results show also that the values of diffusion coefficient and surface microhardness of the treated samples are high to be 3.4 x 10{sup -1} {mu}m{sup 2}/s and 1880 kg/mm{sup 2}, respectively.

  1. Influence of gas pressure and substrate temperature on PIII nitrocarburizing process of AISI 304 stainless steel

    Science.gov (United States)

    Abd El-Rahman, A. M.; El-Hossary, F. M.; Negm, N. Z.; Prokert, F.; Richter, E.; Möller, W.

    2004-12-01

    Plasma immersion ion implantation (PIII) has been used to modify the surface properties of 304 austenitic stainless steel (AISI). The influence of working gas pressure, 0.2-1.0 Pa, and substrate temperature, 300-500 °C, on the microstructure, treating rate, nitrogen/carbon concentration depth profile, and surface microhardness was investigated. A gas composition of 25% C2H2, 75% N2, r.f. plasma power input of 350 W, and a negatively biased potential of 30 kV were fixed during the experiment. The experimental results show that the substrate temperature and the diffusion process of nitrogen and carbon depend on the gas pressure inside the plasma chamber. The thickness of the modified layer has been found to be more than 30 μm for samples were treated in the plasma for 60 min. The results show also that the values of diffusion coefficient and surface microhardness of the treated samples are high to be 3.4 × 10-1 μm2/s and 1880 kg/mm2, respectively.

  2. Influence of Attachment Pressure and Kinematic Configuration on pHRI with Wearable Robots

    Directory of Open Access Journals (Sweden)

    André Schiele

    2009-01-01

    Full Text Available The goal of this paper is to show the influence of exoskeleton attachment, such as the pressure on the fixation cuffs and alignment of the robot joint to the human joint, on subjective and objective performance metrics (i.e. comfort, mental load, interface forces, tracking error and available workspace during a typical physical human-robot interaction (pHRI experiment. A mathematical model of a single degree of freedom interaction between humans and a wearable robot is presented and used to explain the causes and characteristics of interface forces between the two. The pHRI model parameters (real joint offsets, attachment stiffness are estimated from experimental interface force measurements acquired during tests with 14 subjects. Insights gained by the model allow optimisation of the exoskeleton kinematics. This paper shows that offsets of more than ±10 cm exist between human and robot axes of rotation, even if a well-designed exoskeleton is aligned properly before motion. Such offsets can create interface loads of up to 200 N and 1.5 Nm in the absence of actuation. The optimal attachment pressure is determined to be 20 mmHg and the attachment stiffness is about 300 N/m. Inclusion of passive compensation joints in the exoskeleton is shown to lower the interaction forces significantly, which enables a more ergonomic pHRI.

  3. Influence of the oxygen partial pressure on the phase evolution during Bi-2212 wire melt processing

    CERN Document Server

    C. Scheuerlein; M.O. Rikel; J. Kadar; C. Doerrer; M. Di Michiel; A. Ballarino; L. Bottura; J. Jiang; F. Kametani; E.E. Hellstrom; D.C. Larbalestier; 10.1109/TASC.2016.2533574

    2016-01-01

    We have studied the influence of the oxygen partial pressure pO2 up to 5.5 bar on the phase changes that occur during melt processing of a state-of-the-art Bi-2212 multifilamentary wire. Phase changes have been monitored in situ by high energy synchrotron X-ray diffraction (XRD). We found that the stability of Bi-2212 phase is reduced with increasing pO2. For pO2>1 bar a significant amount of Bi-2212 phase decomposes upon heating in the range 400 to 650 °C. The extent of decomposition strongly increases with increasing pO2, and at pO2=5.5 bar Bi-2212 decomposes completely in the solid state. Textured Bi-2212 can be formed during solidification when pO2 is reduced to 0.45 bar when the precursor is molten. Since the formation of current limiting second phases is very sensitive to pO2 when it exceeds 1 bar, we recommend to reduce the oxygen partial pressure below the commonly used pO2=1 bar, in order to increase the pO2 margins and to make the overpressure process more robust.

  4. Airway obstruction and gas leak during mask ventilation of preterm infants in the delivery room.

    LENUS (Irish Health Repository)

    2011-07-01

    Preterm infants with inadequate breathing receive positive pressure ventilation (PPV) by mask with variable success. The authors examined recordings of PPV given to preterm infants in the delivery room for prevalence of mask leak and airway obstruction.

  5. Influence of pressure on the efficiency of a structured packing. Influencia de la presion sobre la eficacia de un relleno estructurado en destilacion en vacio

    Energy Technology Data Exchange (ETDEWEB)

    Rosello Segado, A.; Martin Aguilar, A.; Cota Galan, J. (Departamento de Ingeneria Quimica. Sevilla (Spain))

    1994-01-01

    The method to consider the influence of pressure on the efficiency of a structured packing is discussed, appointing the most suitable way to isolate that influence. Height of transfer unit data for different binary mixtures at constant composition and reduced pressures have been obtained. Results show a change of efficiency, but only when the change of pressure is very important. (Author) 17 refs.

  6. 经鼻持续气道正压给氧多中心临床试验研究%A multi-center clinical trial of oxygen administration with nasal continuous positive airway pressure

    Institute of Scientific and Technical Information of China (English)

    持续气道正压给氧临床试验协作组

    2008-01-01

    目的 评价经鼻持续气道正压(CPAP)给氧的效果.方法 2003年1月至2007年12月首都儿科研究所(牵头)和北京市9家郊区县医院对107例因肺部疾患导致低氧血症新生儿和婴幼儿进行多中心临床试验,通过脉搏血氧仪并结合临床观察对国产的CPAP氧疗仪和普通给氧方法 (面罩、头罩)在改善血氧饱和度的效果方面进行评价.结果 CPAP治疗组46例,普通给氧组61例.应用CPAP后新生儿组在给氧后0.5 h及2 h血氧饱和度为(88.6±7.9)%及(94.4±5.0)%,普通给氧组为(82.4±5.7)%及(90.3±4.5)%,两组间差异有显著性(P<0.05).婴幼儿组在CPAP给氧后1 h血氧饱和度为(95.7±2.6)%,普通给氧组为(87.3±15.8)%,两组间差异有显著性(P<0.05).给氧后紫绀和呼吸困难程度的改善,CPAP组优于普通给氧组.结论 经鼻CPAP氧疗仪是适用于基层、安全、有效、效果优于普通给氧方法 的给氧工具.%Objective To evaluate the effect of nasal continuous positive airway pressure (CPAP).Methods A randomized controlled multi-center clinical trial was conducted during January 2003 to December 2007 in 107 newborns and infants with hypoxemia due to pulmonary diseases.These patients were hospitalized in Capital Institute of Pediatrics and 9 local hospitals.The changes of arterial oxygen saturation and clinical signs were studied after CPAP treatment and conventional oxygen therapy.Results CPAP group recruited 46 cases,conventional oxygen therapy group included 61 cases.After CPAP treatment,oxygen saturation values in newborns at 0.5 and 2 hour were (88.6±7.9)% and (94.4±5.0)%,and there was significant difference as compared with those in conventional oxygen therapy group [(82.4±5.7)% and (90.3±4.5)%].Oxygen saturation value of infants with CPAP at 1 hour was (95.7±2.6)%,and there was significant difference as compared with that in conventional oxygen therapy group[(87.3±15.8)%].Oxygen therapy alleviated the severity of cyanosis and dyspnea

  7. Influence of ethylene glycol pretreatment on effectiveness of atmospheric pressure plasma treatment of polyethylene fibers

    Energy Technology Data Exchange (ETDEWEB)

    Wen Ying; Li Ranxing [Key Laboratory of Textile Science and Technology (Donghua University), Ministry of Education (China); Cai Fang [Key Laboratory of Eco-Textiles (Donghua University), Ministry of Education (China); Fu Kun; Peng Shujing; Jiang Qiuran; Yao Lan [Key Laboratory of Textile Science and Technology (Donghua University), Ministry of Education (China); Qiu Yiping, E-mail: ypqiu@dhu.edu.cn [Department of Textile Materials Science and Product Design, College of Textiles, Donghua University, Shanghai 201620 (China)

    2010-03-01

    For atmospheric pressure plasma treatments, the results of plasma treatments may be influenced by liquids adsorbed into the substrate. This paper studies the influence of ethylene glycol (EG) pretreatment on the effectiveness of atmospheric plasma jet (APPJ) treatment of ultrahigh molecular weight polyethylene (UHMWPE) fibers with 0.31% and 0.42% weight gain after soaked in EG/water solution with concentration of 0.15 and 0.3 mol/l for 24 h, respectively. Scanning electron microscopy (SEM) shows that the surface of fibers pretreated with EG/water solution does not have observable difference from that of the control group. The X-ray photoelectron spectroscopy (XPS) results show that the oxygen concentration on the surface of EG-pretreated fibers is increased less than the plasma directly treated fibers. The interfacial shear strength (IFSS) of plasma directly treated fibers to epoxy is increased almost 3 times compared with the control group while that of EG-pretreated fibers to epoxy does not change except for the fibers pretreated with lower EG concentration and longer plasma treatment time. EG pretreatment reduces the water contact angle of UHMWPE fibers. In conclusion, EG pretreatment can hamper the effect of plasma treatment of UHMWPE fibers and therefore longer plasma treatment duration is required for fibers pretreated with EG.

  8. The major influence of the atmosphere on intracranial pressure: an observational study

    Science.gov (United States)

    Herbowski, Leszek

    2017-01-01

    The impact of the atmosphere on human physiology has been studied widely within the last years. In practice, intracranial pressure is a pressure difference between intracranial compartments and the surrounding atmosphere. This means that gauge intracranial pressure uses atmospheric pressure as its zero point, and therefore, this method of pressure measurement excludes the effects of barometric pressure's fluctuation. The comparison of these two physical quantities can only take place through their absolute value relationship. The aim of this study is to investigate the direct effect of barometric pressure on the absolute intracranial pressure homeostasis. A prospective observational cross-sectional open study was conducted in Szczecin, Poland. In 28 neurosurgical patients with suspected normal-pressure hydrocephalus, intracranial intraventricular pressure was monitored in a sitting position. A total of 168 intracranial pressure and atmospheric pressure measurements were performed. Absolute atmospheric pressure was recorded directly. All values of intracranial gauge pressure were converted to absolute pressure (the sum of gauge intracranial pressure and local absolute atmospheric pressure). The average absolute mean intracranial pressure in the patients is 1006.6 hPa (95 % CI 1004.5 to 1008.8 hPa, SEM 1.1), and the mean absolute atmospheric pressure is 1007.9 hPa (95 % CI 1006.3 to 1009.6 hPa, SEM 0.8). The observed association between atmospheric and intracranial pressure is strongly significant (Spearman correlation r = 0.87, p < 0.05) and all the measurements are perfectly reliable (Bland-Altman coefficient is 4.8 %). It appears from this study that changes in absolute intracranial pressure are related to seasonal variation. Absolute intracranial pressure is shown to be impacted positively by atmospheric pressure.

  9. The major influence of the atmosphere on intracranial pressure: an observational study

    Science.gov (United States)

    Herbowski, Leszek

    2016-06-01

    The impact of the atmosphere on human physiology has been studied widely within the last years. In practice, intracranial pressure is a pressure difference between intracranial compartments and the surrounding atmosphere. This means that gauge intracranial pressure uses atmospheric pressure as its zero point, and therefore, this method of pressure measurement excludes the effects of barometric pressure's fluctuation. The comparison of these two physical quantities can only take place through their absolute value relationship. The aim of this study is to investigate the direct effect of barometric pressure on the absolute intracranial pressure homeostasis. A prospective observational cross-sectional open study was conducted in Szczecin, Poland. In 28 neurosurgical patients with suspected normal-pressure hydrocephalus, intracranial intraventricular pressure was monitored in a sitting position. A total of 168 intracranial pressure and atmospheric pressure measurements were performed. Absolute atmospheric pressure was recorded directly. All values of intracranial gauge pressure were converted to absolute pressure (the sum of gauge intracranial pressure and local absolute atmospheric pressure). The average absolute mean intracranial pressure in the patients is 1006.6 hPa (95 % CI 1004.5 to 1008.8 hPa, SEM 1.1), and the mean absolute atmospheric pressure is 1007.9 hPa (95 % CI 1006.3 to 1009.6 hPa, SEM 0.8). The observed association between atmospheric and intracranial pressure is strongly significant (Spearman correlation r = 0.87, p < 0.05) and all the measurements are perfectly reliable (Bland-Altman coefficient is 4.8 %). It appears from this study that changes in absolute intracranial pressure are related to seasonal variation. Absolute intracranial pressure is shown to be impacted positively by atmospheric pressure.

  10. Influence of harvesting pressure on demographic tactics: Implications for wildlife management

    Science.gov (United States)

    Servanty, S.; Gaillard, J.-M.; Ronchi, F.; Focardi, S.; Baubet, E.; Gimenez, O.

    2011-01-01

    Demographic tactics within animal populations are shaped by selective pressures. Exploitation exerts additional pressures so that differing demographic tactics might be expected among populations with differences in levels of exploitation. Yet little has been done so far to assess the possible consequences of exploitation on the demographic tactics of mammals, even though such information could influence the choice of effective management strategies. Compared with similar-sized ungulate species, wild boar Sus scrofa has high reproductive capabilities, which complicates population management. Using a perturbation analysis, we investigated how population growth rates (??) and critical life-history stages differed between two wild boar populations monitored for several years, one of which was heavily harvested and the other lightly harvested. Asymptotic ?? was 1??242 in the lightly hunted population and 1??115 in the heavily hunted population, while the ratio between the elasticity of adult survival and juvenile survival was 2??63 and 1??27, respectively. A comparative analysis including 21 other ungulate species showed that the elasticity ratio in the heavily hunted population was the lowest ever observed. Compared with expected generation times of similar-sized ungulates (more than 6years), wild boar has a fast life-history speed, especially when facing high hunting pressure. This is well illustrated by our results, where generation times were 3??6years in the lightly hunted population and only 2??3years in the heavily hunted population. High human-induced mortality combined with non-limiting food resources accounted for the accelerated life history of the hunted population because of earlier reproduction. Synthesis and applications. For wild boar, we show that when a population is facing a high hunting pressure, increasing the mortality in only one age-class (e.g. adults or juveniles) may not allow managers to limit population growth. We suggest that simulations of

  11. Hemodynamic responses and upper airway morbidity following tracheal intubation in patients with hypertension: conventional laryngoscopy versus an intubating laryngeal mask airway

    Directory of Open Access Journals (Sweden)

    Elif Bengi Sener

    2012-01-01

    Full Text Available OBJECTIVES: We compared hemodynamic responses and upper airway morbidity following tracheal intubation via conventional laryngoscopy or intubating laryngeal mask airway in hypertensive patients. METHODS: Forty-two hypertensive patients received a conventional laryngoscopy or were intubated with a intubating laryngeal mask airway. Anesthesia was induced with propofol, fentanyl, and cis-atracurium. Measurements of systolic and diastolic blood pressures, heart rate, rate pressure product, and ST segment changes were made at baseline, preintubation, and every minute for the first 5 min following intubation. The number of intubation attempts, the duration of intubation, and airway complications were recorded. RESULTS: The intubation time was shorter in the conventional laryngoscopy group than in the intubating laryngeal mask airway group (16.33 ± 10.8 vs. 43.04±19.8 s, respectively (p<0.001. The systolic and diastolic blood pressures in the intubating laryngeal mask airway group were higher than those in the conventional laryngoscopy group at 1 and 2 min following intubation (p<0.05. The rate pressure product values (heart rate x systolic blood pressure at 1 and 2 min following intubation in the intubating laryngeal mask airway group (15970.90 ± 3750 and 13936.76 ± 2729, respectively were higher than those in the conventional laryngoscopy group (13237.61 ± 3413 and 11937.52 ± 3160, respectively (p<0.05. There were no differences in ST depression or elevation between the groups. The maximum ST changes compared with baseline values were not significant between the groups (conventional laryngoscopy group: 0.328 mm versus intubating laryngeal mask airway group: 0.357 mm; p = 0.754. The number and type of airway complications were similar between the groups. CONCLUSION: The intense and repeated oropharyngeal and tracheal stimulation resulting from intubating laryngeal mask airway induces greater pressor responses than does stimulation resulting from

  12. Using optical coherence tomography (OCT) imaging in the evaluation of airway dynamics (Conference Presentation)

    Science.gov (United States)

    Szabari, Margit V.; Kelly, Vanessa J.; Applegate, Matthew B.; Chee, Chunmin; Tan, Khay M.; Hariri, Lida P.; Harris, R. Scott; Winkler, Tilo; Suter, Melissa J.

    2016-03-01

    Asthma is a chronic disease resulting in periodic attacks of coughing and wheezing due to temporarily constricted and clogged airways. The pathophysiology of asthma and the process of airway narrowing are not completely understood. Appropriate in vivo imaging modality with sufficient spatial and temporal resolution to dynamically assess the behavior of airways is missing. Optical coherence tomography (OCT) enables real-time evaluation of the airways during dynamic and static breathing maneuvers. Our aim was to visualize the structure and function of airways in healthy and Methacholine (MCh) challenged lung. Sheep (n=3) were anesthetized, mechanically ventilated and imaged with OCT in 4 dependent and 4 independent airways both pre- and post-MCh administration. The OCT system employed a 2.4 Fr (0.8 mm diameter) catheter and acquired circumferential cross-sectional images in excess of 100 frames per second during dynamic tidal breathing, 20 second static breath-holds at end-inspiration and expiration pressure, and in a response to a single deep inhalation. Markedly different airway behavior was found in dependent versus non-dependent airway segments before and after MCh injection. OCT is a non-ionizing light-based imaging modality, which may provide valuable insight into the complex dynamic behavior of airway structure and function in the normal and asthmatic lung.

  13. Potential role of the airway wall in the asthma of obesity.

    Science.gov (United States)

    Bates, Jason H T; Dixon, Anne E

    2015-01-01

    The pathogenesis of late-onset TH2-low asthma in obesity is thought to be related to weight-related decreases in lung volume, but why only a subset of individuals with obesity develop this condition is unknown. We tested the hypothesis that natural variations in both airway wall stiffness and airway wall thickness could lead to a subpopulation of hyperresponsive individuals exhibiting the symptoms of asthma in the setting of obesity. Increases in airway resistance (Raw) after airway smooth muscle stimulation were simulated using a computational model of an elastic airway embedded in elastic parenchyma. Using a range of randomly chosen values for both airway wall stiffness and thickness, we determined the resulting probability distributions of Raw responsiveness for a variety of different levels of transpulmonary pressure (Ptp). As Ptp decreased from 5 to 1 cmH2O, the resulting distributions of Raw moved toward progressively higher levels of responsiveness. With appropriate choices for the mean and standard deviation of the parameter that controls either airway wall stiffness or thickness, the model predicts a relationship between airway hyperresponsiveness and body mass index that is similar to that which has been reported in populations with obesity. We conclude that natural variations in airway wall mechanics and geometry between different individuals can potentially explain why an increasing percentage of the population exhibits the symptoms of asthma as the obesity of the population increases.

  14. Influence of an Optimized Thermoelectric Generator on the Back Pressure of the Subsequent Exhaust Gas System of a Vehicle

    Science.gov (United States)

    Kühn, Roland; Koeppen, Olaf; Kitte, Jens

    2014-06-01

    Numerous research projects in automotive engineering focus on the industrialization of the thermoelectric generator (TEG). The development and the implementation of thermoelectric systems into the vehicle environment are commonly supported by virtual design activities. In this paper a customized simulation architecture is presented that includes almost all vehicle parts which are influenced by the TEG (overall system simulation) but is nevertheless capable of real-time use. Moreover, an optimized planar TEG with minimum nominal power output of about 580 W and pressure loss at nominal conditions of 10 mbar, synthesized using the overall system simulation, and the overall system simulation itself are used to answer a generally neglected question: What influence does the position of a TEG have on the back pressure of the subsequent exhaust gas system of the vehicle? It is found that the influence of the TEG on the muffler is low, but the catalytic converter is strongly influenced. It is shown that the TEG can reduce the back pressure of an exhaust gas system so much that its overall back pressure is less than the back pressure of a standard exhaust gas system.

  15. High hydrostatic pressure influences the in vitro response to xenobiotics in Dicentrarchus labrax liver

    Energy Technology Data Exchange (ETDEWEB)

    Lemaire, Benjamin; Mignolet, Eric; Debier, Cathy [Institut des Sciences de la Vie, Université Catholique de Louvain, Croix du Sud 2, B-1348 Louvain-la-Neuve (Belgium); Calderon, Pedro Buc [Louvain Drug Research Institute, Université Catholique de Louvain, Avenue Mounier 73, B-1200 Woluwé-Saint-Lambert (Belgium); Thomé, Jean Pierre [Laboratoire d’Ecologie Animale et Ecotoxicologie, Université de Liège, Allée du 6 août 15, B-4000 Liège (Belgium); Rees, Jean François, E-mail: jf.rees@uclouvain.be [Institut des Sciences de la Vie, Université Catholique de Louvain, Croix du Sud 2, B-1348 Louvain-la-Neuve (Belgium)

    2016-04-15

    Highlights: • The methodology of precision-cut liver slices was applied to the European seabass. • Liver slices remained viable and functional in short-term co-exposure studies. • CYP1A induction was blocked in slices exposed to an AhR agonist at high pressure. • HSP70 induction was lower in slices exposed to an AhR agonist at high pressure. • Oxidative stress responses to tBHP were less pronounced at high pressure. - Abstract: Hydrostatic pressure (HP) increases by about 1 atmosphere (0.1 MPa) for each ten-meter depth increase in the water column. This thermodynamical parameter could well influence the response to and effects of xenobiotics in the deep-sea biota, but this possibility remains largely overlooked. To grasp the extent of HP adaptation in deep-sea fish, comparative studies with living cells of surface species exposed to chemicals at high HP are required. We initially conducted experiments with precision-cut liver slices of a deep-sea fish (Coryphaenoides rupestris), co-exposed for 15 h to the aryl hydrocarbon receptor (AhR) agonist 3-methylcholanthrene at HP levels representative of the surface (0.1 MPa) and deep-sea (5–15 MPa; i.e., 500–1500 m depth) environments. The transcript levels of a suite of stress-responsive genes, such as the AhR battery CYP1A, were subsequently measured (Lemaire et al., 2012; Environ. Sci. Technol. 46, 10310–10316). Strikingly, the AhR agonist-mediated increase of CYP1A mRNA content was pressure-dependently reduced in C. rupestris. Here, the same co-exposure scenario was applied for 6 or 15 h to liver slices of a surface fish, Dicentrarchus labrax, a coastal species presumably not adapted to high HP. Precision-cut liver slices of D. labrax were also used in 1 h co-exposure studies with the pro-oxidant tert-butylhydroperoxide (tBHP) as to investigate the pressure-dependence of the oxidative stress response (i.e., reactive oxygen production, glutathione and lipid peroxidation status). Liver cells remained

  16. Prognostic Effects of Obstructive Sleep Apnea Treated with Continuous Positive Airway Pressure or Upper Airway Surgery on Coronary Heart Disease: A Systematic Review%持续气道正压通气或上呼吸道手术治疗对合并阻塞性睡眠呼吸暂停冠心病患者预后影响的系统评价

    Institute of Scientific and Technical Information of China (English)

    王少丽; 史大卓; 王承龙

    2012-01-01

    Objective To evaluate prognostic impact of treatment with Continuous Positive Airway Pressure (CPAP) or upper airway surgery on the patients with obstructive sleep apnea (OSA) and coronary heart disease (CHD). Methods Database search in The Cochrane Library, PubMed, OVID and CBM (from establishment dates to October 2009) were conducted. Cohort studies and randomized controlled trials of OSA with CPAP or upper airway surgery in CHD patients were identified. We assessed the quality of the included trials and extracted the relevant data. Statistical analysis was performed using RevMan 4.3.2 software. Results A total of 4 cohort studies involving 945 participants were included. The results of meta-analysis were as follows: a) there were no significant differences in the rate of late lumen loss and 10-year mortality between CHD patients with OSA treated by CPAP and those without OSA (RR=1.84, 95%CI 0.73 to 4.68, P=0.20; RR=0.80, 95%CI 0.24 to 2.64, P=0.71). b) CPAP or uvulopalatopharyngoplasty used in the treatment of OSA on CHD patients after PCI had a significant decrease in the rate of 5-year cardiac death when compared with those untreated OSA patients (RR=0.34, 95%CI 0.14 to 0.82, P=0.02). But there were no differences in the rate of 5-year all-cause mortality, major adverse cardiac events (MACE) between the two groups respectively (RR=0.66,95%CI 0.39 to 1.10, P=0.11; RR=0.97, 95%CI 0.81 to 1.15, P=0.69). c) CPAP or upper airway surgery in treating OSA significantly reduced the risk of MACE occurrence during the 86.5±39 months follow-up period (RR=0.22, 95%CI 0.07 to 0.72, P=0.01). Conclusion Current evidence indicates that treating OSA with CPAP or upper airway surgery in CHD patients might be associ-ated with a decrease in the risk of cardiac death. But more studies are necessary to evaluate prognostic impact of treatment with CPAP or upper airway surgery on the patients with OSA and CHD. However, due to the limited quantity and quality of the included studies

  17. Influence and Utilisation of Pressure Propagation in Pipelines for Secondary Controlled Discrete Displacement Cylinders

    DEFF Research Database (Denmark)

    Hansen, Rico Hjerm; Hansen, Anders Hedegaard; Andersen, Torben Ole

    2012-01-01

    Efficient discrete force control of cylinders may be realised by having multi-chambered cylinders, where the pressure of the chambers are shifted between fixed pressure levels of a secondary controlled system. However, the pressure shifting on a volume where the dynamics of pressure propagation...

  18. Understanding the Influence of Pressure and Radial Loads on Stress and Displacement Response of a Rotating Body: The Automobile Wheel

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available This paper highlights the use of the finite element technique for analyzing stress and displacement distributions in wheels of automotive vehicles when subject to the conjoint influence of inflation pressure and radial load. The most commonly used considerations in the design of the rotating body are elucidated. A potentially viable technique for finite element modeling of radial wheel, subjected to loading, is highlighted. The extrinsic influence of inflation pressure on performance of the rotating body, that is, the wheel, is rationalized.

  19. Influence of growth pressure of a GaN buffer layer on the properties of MOCVD GaN

    Institute of Scientific and Technical Information of China (English)

    CHEN; Jun(陈俊); ZHANG; Shuming(张书明); ZHANG; Baoshun(张宝顺); ZHU; Jianjun(朱建军); FENG; Gan(冯淦); DUAN; Lihong(段俐宏); WANG; Yutian(王玉田); YANG; Hui(杨辉); ZHENG; Wenchen(郑文琛)

    2003-01-01

    The influence of growth pressure of GaN buffer layer on the properties of MOCVD GaN on α-Al2O3 has been investigated with the aid of a home-made in situ laser reflectometry measurement system. The results obtained with in situ measurements and scanning electron microscope show that with the increase in deposition pressure of buffer layer, the nuclei increase in size, which roughens the surface, and delays the coalescence of GaN nuclei. The optical and crystalline quality of GaN epilayer was improved when buffer layer was deposited at high pressure.

  20. 无创双水平气道正压通气治疗不同病因致急性呼吸衰竭的临床观察%The Clinical Observation of Noninvasive Bilevel Positive Airway Pressure Ventilation on Acute Respiratory Failure Caused by Different Etiology

    Institute of Scientific and Technical Information of China (English)

    温振杰; 陈军; 刘建凌

    2014-01-01

    目的:探讨无创双水平气道正压通气治疗不同病因致急性呼吸衰竭临床效果。方法选择急性呼吸衰竭患者共48例,根据不同病因分为观察组(心源性肺水肿)和对照组(重症肺炎)。两组均实施无创双水平气道正压通气治疗。观察两组治疗效果。结果观察组治疗后的动脉血气指标分别和对照组治疗6 h后的动脉血气指标比较,差异有统计学意义(P<0.05)。观察组患者症状缓解时间、无创双水平正压通气治疗时间、住院时间、气管插管发生分别和对照组比较,差异有统计学意义(P<0.05)。结论无创双水平气道正压通气对心源性肺水肿和重症肺炎所致急性呼吸衰竭均有显著治疗效果,但对心源性肺水肿所致急性呼吸衰竭效果更佳。%Objective To explore the effect of noninvasive bilevel positive airway pressure ventilation on acute respiratory failure caused by different etiology. Methods 48 cases with acute respiratory failure were divided into observation group (cardiogenic pulmonary edema) and control group (severe pneumonia) according to different causes. The two groups underwent noninvasive bilevel positive airway pressure ventilation. The therapeutic effect of two groups was observed . Results The arterial blood gas indexes in the observation group compared with those in control group after six hours treatment respectively,the difference was statistically significant (P<0.05).The symptoms time, noninvasive bilevel positive pressure ventilation time, hospitalization time, tracheal intubation occurred in the observation group compared with those in control group after treatment respectively, the difference was statistically significant (P<0.05).Conclusion The noninvasive bilevel positive airway pressure ventilation on acute respiratory failure caused by acute cardiogenic pulmonary edema or severe pneumonia has significant effect, but its efficacy in patients with

  1. [Acute pulmonary edema secondary to acute upper airway obstruction].

    Science.gov (United States)

    Sánchez-Ortega, J L; Carpintero-Moreno, F; Olivares-López, A; Borrás-Rubio, E; Alvarez-López, M J; García-Izquierdo, A

    1992-01-01

    We report a 72 years old woman with mild arterial hypertension and no other pathological history who presented an acute pulmonary edema due to acute obstruction of the upper airway secondary to vocal chord paralysis developing during the immediate postoperative phase of thyroidectomy. The acute pulmonary edema resolved after application of tracheal reintubation, mechanical ventilation controlled with end expiratory positive pressure, diuretics, morphine, and liquid restriction. We discuss the possible etiopathogenic possibilities of this infrequent clinical picture and we suggest that all patients who suffered and acute obstruction of the upper airways require a careful clinical surveillance in order to prevent the development of the pulmonary syndrome.

  2. Upper airway obstruction during midazolam sedation: modification by nasal CPAP.

    Science.gov (United States)

    Nozaki-Taguchi, N; Isono, S; Nishino, T; Numai, T; Taguchi, N

    1995-08-01

    We examined the depressant effect of midazolam on respiration in 21 healthy women undergoing lower abdominal surgery with spinal anaesthesia. Airway gas flow, airway pressure, and the sound of snoring were recorded together with arterial oxygen saturation (SpO2). After spinal anaesthesia was established, subjects were deeply sedated with pentazocine 15 mg followed by incremental doses of midazolam 1 mg i.v. up to 0.1 mg.kg-1. When SpO2 decreased to midazolam sedation for spinal anaesthesia.

  3. 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.

  4. Investigation of influencing factors of hot streaks migration in high pressure stage of a vaneless counter-rotating turbine

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Three-dimensional,viscous,and unsteady CFD simulations have been performed in order to reveal the influencing factors of hot streaks migration in high pressure stage of a vaneless counter-rotating turbine. Based on the numerical results,the comparison between the case with inlet hot streaks and case without inlet hot streaks is carried out,which shows that the effect of inlet hot streaks on the load distributions of high pressure turbine airfoils is not notable and the airfoil load distributions are directly related to the inlet pressure distributions. The predicted results also indicate that the circumferential and radial movements of the hot streaks were not observed in the high pressure turbine stator. This means that the combined effects of secondary flow and buoyancy are very weak in the high pres-sure turbine stator. The numerical results also prove that the circumferential flow angle effect at the inlet of the high pressure turbine rotor,secondary flow effect and buoyancy effect are the mainly influencing factors to directly affect the migration characteristics of the hot streaks in the high pressure turbine rotor.

  5. Vessel-guided Airway Tree Segmentation

    DEFF Research Database (Denmark)

    Lo, P.; Sporring, J.; Ashraf, H.;

    2010-01-01

    This paper presents a method for airway tree segmentation that uses a combination of a trained airway appearance model, vessel and airway orientation information, and region growing. We propose a voxel classification approach for the appearance model, which uses a classifier that is trained...... to differentiate between airway and non-airway voxels. This is in contrast to previous works that use either intensity alone or hand crafted models of airway appearance. We show that the appearance model can be trained with a set of easily acquired, incomplete, airway tree segmentations. A vessel orientation...

  6. Airway complications after lung transplantation.

    Science.gov (United States)

    Machuzak, Michael; Santacruz, Jose F; Gildea, Thomas; Murthy, Sudish C

    2015-01-01

    Airway complications after lung transplantation present a formidable challenge to the lung transplant team, ranging from mere unusual images to fatal events. The exact incidence of complications is wide-ranging depending on the type of event, and there is still evolution of a universal characterization of the airway findings. Management is also wide-ranging. Simple observation or simple balloon bronchoplasty is sufficient in many cases, but vigilance following more severe necrosis is required for late development of both anastomotic and nonanastomotic airway strictures. Furthermore, the impact of coexisting infection, rejection, and medical disease associated with high-level immunosuppression further complicates care.

  7. Airway vascular reactivity and vascularisation in human chronic airway disease

    NARCIS (Netherlands)

    Bailey, Simon R; Boustany, Sarah; Burgess, Janette K; Hirst, Stuart J; Sharma, Hari S; Simcock, David E; Suravaram, Padmini R; Weckmann, Markus

    2009-01-01

    Altered bronchial vascular reactivity and remodelling including angiogenesis are documented features of asthma and other chronic inflammatory airway diseases. Expansion of the bronchial vasculature under these conditions involves both functional (vasodilation, hyperperfusion, increased microvascular

  8. Influence of asphaltene aggregation and pressure on crude oil emulsion stability

    Energy Technology Data Exchange (ETDEWEB)

    Auflem, Inge Harald

    2002-07-01

    Water-in-crude oil emulsions stabilised by various surface-active components are one of the major problems in relation to petroleum production. This thesis presents results from high-pressure separation experiments on ''live'' crude oil and model oil emulsions, as well as studies of Interactions between various indigenous stabilising materials in crude oil. A high-pressure separation rig was used to study the influence of gas and gas bubbles on the separation of water-in-crude oil emulsions. The results were interpreted as a flotation effect from rising gas bubbles, which led to increased separation efficiency. The separation properties of a ''live'' crude oil were compared to crude oil samples recombined with various gases. The results showed that water-in-oil emulsions produced from the ''live'' crude oil samples, generally separated faster and more complete, than emulsions based on recombined samples of the same crude oil. Adsorption of asphaltenes and resins onto a hydrophilic surface from solutions with varying aromatic/aliphatic character was investigated by a quarts crystal microbalance. The results showed that asphaltenes adsorbed to a larger degree than the resins. The resins were unable to desorb pre-adsorbed asphaltenes from the surface, and neither did they adsorb onto the asphaltene-coated surface. In solutions of both of resins and asphaltenes the two constituents associated in bulk liquid and adsorbed to the surface in the form of mixed aggregates. Near infrared spectroscopy and pulsed field gradient spin echo nuclear magnetic resonance were used to study asphaltene aggregation and the influence of various amphiphiles on the asphaltene aggregate size. The results showed Interactions between the asphaltenes and various chemicals, which were proposed to be due to acid-base interactions. Among the chemicals used were various naphthenic acids. Synthesised monodisperse acids gave a reduction of

  9. Aging increases upper airway collapsibility in Fischer 344 rats.

    Science.gov (United States)

    Ray, Andrew D; Ogasa, Toshiyuki; Magalang, Ulysses J; Krasney, John A; Farkas, Gaspar A

    2008-11-01

    The upper airway muscles play an important role in maintaining upper airway collapsibility, and the incidence of sleep-disordered breathing increases with age. We hypothesize that the increase in airway collapsibility with increasing age can be linked to changes in upper airway muscle mechanics and structure. Eight young (Y: 6 mo) and eight old (O: 30 mo) Fischer 344 rats were anesthetized and mechanically ventilated, and the pharyngeal pressure associated with flow limitation (Pcrit) was measured 1) with the hypoglossal (cnXII) nerve intact, 2) following bilateral cnXII denervation, and 3) during cnXII stimulation. With the cnXII intact, the upper airways of older rats were more collapsible compared with their younger counterparts [Pcrit = -7.1 +/- 0.6 (SE) vs. -9.5 +/- 0.7 cmH2O, respectively; P = 0.033]. CnXII denervation resulted in an increase in Pcrit such that Pcrit became similar in both groups (O: -4.2 +/- 0.5 cmH2O; Y: -5.4 +/- 0.5 cmH2O). In all rats, cnXII stimulation decreased Pcrit (less collapsible) in both groups (O: -11.3 +/- 1.0 cmH2O; Y: -10.2 +/- 1.0 cmH2O). The myosin heavy chain composition of the genioglossus muscle demonstrated a decrease in the percentage of the IIb isoform (38.3 +/- 2.5 vs. 21.7 +/- 1.7%; P collapsible with age and that the increase in upper airway collapsibility with age is likely related to altered neural control rather than to primary alterations in upper airway muscle structure and function.

  10. Airway Epithelium Stimulates Smooth Muscle Proliferation

    OpenAIRE

    Malavia, Nikita K.; Raub, Christopher B.; Mahon, Sari B.; Brenner, Matthew; Reynold A Panettieri; George, Steven C.

    2009-01-01

    Communication between the airway epithelium and stroma is evident during embryogenesis, and both epithelial shedding and increased smooth muscle proliferation are features of airway remodeling. Hence, we hypothesized that after injury the airway epithelium could modulate airway smooth muscle proliferation. Fully differentiated primary normal human bronchial epithelial (NHBE) cells at an air–liquid interface were co-cultured with serum-deprived normal primary human airway smooth muscle cells (...

  11. Identifying the critical factors that influence intraocular pressure using an automated regression tree

    Directory of Open Access Journals (Sweden)

    Nishanee Rampersad

    2017-01-01

    Full Text Available Background: Assessment of intraocular pressure (IOP is an important test in glaucoma. In addition, anterior segment variables may be useful in screening for glaucoma risk. Studies have investigated the associations between IOP and anterior segment variables using traditional statistical methods. The classification and regression tree (CART method provides another dimension to detect important variables in a relationship automatically.Aim: To identify the critical factors that influence IOP using a regression tree.Methods: A quantitative cross-sectional research design was used. Anterior segment variables were measured in 700 participants using the iVue100 optical coherence tomographer, Oculus Keratograph and Nidek US-500 ultrasonographer. A Goldmann applanation tonometer was used to measure IOP. Data from only the right eyes were analysed because of high levels of interocular symmetry. A regression tree model was generated with the CART method and Pearson’s correlation coefficients were used to assess the relationships between the ocular variables.Results: The mean IOP for the entire sample was 14.63 mmHg ± 2.40 mmHg. The CART method selected three anterior segment variables in the regression tree model. Central corneal thickness was the most important variable with a cut-off value of 527 µm. The other important variables included average paracentral corneal thickness and axial anterior chamber depth. Corneal thickness measurements increased towards the periphery and were significantly correlated with IOP (r ≥ 0.50, p ≤ 0.001.Conclusion: The CART method identified the anterior segment variables that influenced IOP. Understanding the relationship between IOP and anterior segment variables may help to clinically identify patients with ocular risk factors associated with elevated IOPs.

  12. Bi level positive airway pressure ( Bipap ) treatment of overlap syndrome patients quality of life%双水平气道正压( Bipap)呼吸机治疗对重叠综合征患者生存质量的影响

    Institute of Scientific and Technical Information of China (English)

    田迎春; 代云红; 何建林

    2012-01-01

    Objective To investigate the effect of bi-level positive airway pressure ( Bipap ) treatment of overlap syndrome patients quality of life. Methods A random number method 103 patients with overlap syndrome were divided into the experimental group 55 cases and control group 48 cases. Two groups of patients were implemented in routine treatment, experimental group on the basis of with bi-level positive airway pressure ( Bipap) ventilator therapy. 24 weeks later, using the health status questionnaire ( Medical Oatcome Stady Short-forn36, Mos Sf-36 ) to evaluate the patient's quality of life. Results After treatment, the health status questionnaire ( Mos Sf-36 ) in physiological function, life skills, emotional role function, mental health score increased ( P < 0. 05). Conclusion Bi-level positive airway pressure ( Bipap ) ventilator treatment can improve the patients quality of life.%目的 探讨双水平气道正压(Bipap)呼吸机治疗对重叠综合征患者生存质量的影响.方法 采用随机数字法将103例重叠综合征患者分为试验组55例和对照组48例.两组患者均实施常规治疗,试验组在此基础上配合双水平气道正压(Bipap)呼吸机治疗.24周后,采用健康状况调查问卷(Medical Oatcome Stady Short-forn36,Mos Sf-36)评定患者的生存质量.结果 试验组经过治疗后,健康状况问卷( Mos Sf-36)中生理功能、生活能力、情绪角色功能、精神健康评分增加(P<0.05).结论 双水平气道正压(Bipap)呼吸机治疗可提高患者的生活质量

  13. 双水平气道正压通气在重症支气管哮喘治疗中的临床价值%The Clinical Value of Bi-level Positive Airway Pressure Ventilation in the Treatment of Severe Bronchial Asthma

    Institute of Scientific and Technical Information of China (English)

    林鸿浮

    2015-01-01

    Objective To study the clinical value of bi-level positive airway pressure ventilation in the treatment of severe bronchial asthma. Methods 62 patients admitted between January 2010 and December 2014 were divided into two groups, the observation group and the control group, with 32 cases in each by the treatment method. The observation group were treated by bi-level positive airway pressure ventilation, while the control group were treated by the conventional drugs. And the values of blood gas indexes before and after treatment and length of stay were compared between the two groups. Results After treatment, the value of PaO2, SaO2, PaCO2, length of stay was (95.6±5.6)mmHg, (92.8±4.6)%, (42.8±3.2)mmHg and (7.3±2.1)d, respectively in the observation group, and compared with the values of the above indexes in the control group, the differences were statistically significant (P<0.05). Conclusion Bi-level positive airway pressure ventilation has signifi-cant clinical effect in the treatment of severe bronchial asthma.%目的:研究双水平气道正压通气在重症支气管哮喘治疗中的临床价值。方法整群选取2010年1月-2014年12月收治的62例患者为研究对象,按治疗方法分为两组(各32例),观察组双水平气道正压通气,对照组常规药物,比较治疗前后血气指标变化状况和治疗后住院时间。结果观察组患者治疗后PaO2、SaO2、PaCO2和住院时间分别为(95.6±5.6)mmHg、(92.8±4.6)%、(42.8±3.2)mmHg、(7.3±2.1)d同对照组患者相比(P<0.05)。结论在治疗重症支气管哮喘临床上双水平气道正压通气获得显著效果。

  14. The Influence of Fundamental Frequency and Sound Pressure Level Range on Breathing Patterns in Female Classical Singing

    Science.gov (United States)

    Collyer, Sally; Thorpe, C. William; Callaghan, Jean; Davis, Pamela J.

    2008-01-01

    Purpose: This study investigated the influence of fundamental frequency (F0) and sound pressure level (SPL) range on respiratory behavior in classical singing. Method: Five trained female singers performed an 8-s messa di voce (a crescendo and decrescendo on one F0) across their musical F0 range. Lung volume (LV) change was estimated, and…

  15. Data analysis of the inactivation of foodborne microorganisms under high hydrostatic pressure to establish global kinetic parameters and influencing factors

    NARCIS (Netherlands)

    Santillana Farakos, S.M.; Zwietering, M.H.

    2011-01-01

    The inactivation rate of foodborne microorganisms under high hydrostatic pressure (HHP) is influenced by factors such as substrate, species, strain, temperature, pH, and stage of growth of the cell. In this study, 445 DP-values from previously published data were analyzed, including those from bacte

  16. The Influence of Perceived Parental Expectations and Pressures on Women's Academic Achievement during the First Year of College

    Science.gov (United States)

    Furry, Allyson N.; Sy, Susan R.

    2015-01-01

    Previous research has examined the relationship between parental expectations and student academic performance. However, less attention has been given to the role of different parental pressures in students' achievement during their first semester of college. The purpose of this study is to examine the influence of perceived parental expectations…

  17. Genetic and environmental influences on blood pressure and body mass index in Han Chinese : a twin study

    NARCIS (Netherlands)

    Wu, Ting; Snieder, Harold; Li, Liming; Cao, Weihua; Zhan, Siyan; Lv, Jun; Gao, Wenjing; Wang, Xiaoling; Ding, Xiuhua; Hu, Yonghua

    2011-01-01

    The familial aggregation of blood pressure (BP) may be partly due to the familial aggregation of obesity, caused by genetic and/or environmental factors that influence both. Gene-obesity interactions are expected to result in different heritability estimates for BP at different obesity levels. Howev

  18. Propagule pressure-invasibility relationships: testing the influence of soil fertility and disturbance with Lespedeza cuneata.

    Science.gov (United States)

    Houseman, Gregory R; Foster, Bryan L; Brassil, Chad E

    2014-02-01

    Although invasion risk is expected to increase with propagule pressure (PP), it is unclear whether PP-invasibility relationships follow an asymptotic or some other non-linear form and whether such relationships vary with underlying environmental conditions. Using manipulations of PP, soil fertility and disturbance, we tested how each influence PP-invasibility relationships for Lespedeza cuneata in a Kansas grassland and use recruitment curve models to determine how safe sites may contribute to plant invasions. After three growing seasons, we found that the PP-invasibility relationships best fit an asymptotic model of invasion reflecting a combination of density-independent and density-dependent processes and that seeds were aggregated within the plant community despite efforts to uniformly sow seeds. Consistent with some models, community invasibility decreased with enhanced soil fertility or reduced levels of disturbance in response to changes in the fraction of safe sites. Our results illustrate that disturbance and soil fertility can be a useful organizing principle for predicting community invasibility, asymptotic models are a reasonable starting point for modeling invasion, and new modeling techniques—coupled with classic experimental approaches—can enhance our understanding of the invasion process.

  19. Plasma polymers deposited in atmospheric pressure dielectric barrier discharges: Influence of process parameters on film properties

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Katja, E-mail: k.fricke@inp-greifswald.de [Leibniz Institute for Plasma Science and Technology e.V. (INP Greifswald), Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Girard-Lauriault, Pierre-Luc [Plasma Processing Laboratory, Department of Chemical Engineering, McGill University, 3610 rue University, Montreal, QC H3A 0C5 (Canada); Weltmann, Klaus-Dieter [Leibniz Institute for Plasma Science and Technology e.V. (INP Greifswald), Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany); Wertheimer, Michael R. [Department of Engineering Physics, École Polytechnique de Montréal, Box 6079, Station Centre-Ville, Montreal, QC H3C 3A7 (Canada)

    2016-03-31

    We present results on the deposition of plasma polymer (PP) films in a dielectric barrier discharge system fed with mixtures of argon or nitrogen carrier gas plus different hydrocarbon precursors, where the latter possess different carbon-to-hydrogen ratios: CH{sub 4} < C{sub 2}H{sub 6} < C{sub 2}H{sub 4} = C{sub 3}H{sub 6} < C{sub 2}H{sub 2}. The influence of precursor gas mixture and flow rate, excitation frequency, and absorbed power on PP film compositions and properties has been investigated. The discharge was characterized by electrical measurements, while the chemical compositions and structures of coatings were analysed by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, total combustion, and elastic recoil detection analyses, the latter two for determining carbon-to-hydrogen ratios. Scanning electron microscopy was used to study the coatings' morphology, and profilometry for evaluating deposition rates. - Highlights: • Atmospheric pressure DBD is used to deposit organic hydrocarbon films. • High deposition rates can be achieved by varying the power and/or gas mixture ratio. • Process parameters affect the films' surface chemical composition and morphology. • Deposited films are not soluble in aqueous environment. • No delamination of coatings produced from argon plasma.

  20. Airway management and morbid obesity

    DEFF Research Database (Denmark)

    Kristensen, Michael S

    2010-01-01

    Morbidly obese patients present with excess fatty tissue externally on the breast, neck, thoracic wall and abdomen and internally in the mouth, pharynx and abdomen. This excess tissue tends to make access (intubation, tracheostomy) to and patency (during sedation or mask ventilation) of the upper...... in morbidly obese patients and should be followed by actions to counteract atelectasis formation. The decision as to weather to use a rapid sequence induction, an awake intubation or a standard induction with hypnotics should depend on the thorough airway examination and comorbidity and should not be based...... solely on whether morbid obesity is present or not. It is important to ensure sufficient depth of anaesthesia before initiating manipulation of the airway because inadequate anaesthesia depth predisposes to aspiration if airway management becomes difficult. The intubating laryngeal mask airway is more...

  1. Some specifics of influence of pore pressure on physical properties of deformable rocks

    Science.gov (United States)

    Sobolev, G. A.; Stakhovskaya, Z. I.; Mikayelyan, A. O.

    1984-07-01

    A study was made of a range of problems related to the physical and mechanical properties of limestones from the region of the Ingura hydroelectric powerplant under hydrostatic pore pressure with additional axial pressure. The purpose was to estimate the significance and effect of pore pressure on physical properties in rocks as a function of the stressed state under conditions of hydrostatic pressure and hydrostatic pressure with additional axial loading. The P wave velocity, resistivity and longitudinal deformation were measured under pressure with specimens which had been carefully dried and saturated under vacuum conditions with a 2 n solution of NaCl. Cyclical variations of pore pressure were found to cause compaction of the rock. Cyclical variations of pore pressure under complex stress conditions facilitate fracture and strength loss of the rock.

  2. Do pressure ulcers influence length of hospital stay in surgical cardiothoracic patients? A prospective evaluation.

    NARCIS (Netherlands)

    Schuurman, J.P.; Schoonhoven, L.J.; Keller, B.P.; Ramshorst, B. van

    2009-01-01

    AIM AND OBJECTIVE: The aim and objective of this study was to determine whether the occurrence of pressure ulcers following cardiothoracic surgery increases the length of hospitalisation. BACKGROUND: Literature suggests that a pressure ulcer extends the length of hospital stay. The impact of pressur

  3. Loci influencing blood pressure identified using a cardiovascular gene-centric array

    NARCIS (Netherlands)

    Ganesh, Santhi K.; Tragante, Vinicius; Guo, Wei; Guo, Yiran; Lanktree, Matthew B.; Smith, Erin N.; Johnson, Toby; Castillo, Berta Almoguera; Barnard, John; Baumert, Jens; Chang, Yen-Pei Christy; Elbers, Clara C.; Farrall, Martin; Fischer, Mary E.; Franceschini, Nora; Gaunt, Tom R.; Gho, Johannes M. I. H.; Gieger, Christian; Gong, Yan; Isaacs, Aaron; Kleber, Marcus E.; Mateo Leach, Irene; McDonough, Caitrin W.; Meijs, Matthijs F. L.; Mellander, Olle; Molony, Cliona M.; Nolte, Ilja M.; Padmanabhan, Sandosh; Price, Tom S.; Rajagopalan, Ramakrishnan; Shaffer, Jonathan; Shah, Sonia; Shen, Haiqing; Soranzo, Nicole; van der Most, Peter; Van Iperen, Erik P. A.; Van Setten, Jessic A.; Vonk, Judith M.; Zhang, Li; Beitelshees, Amber L.; Berenson, Gerald S.; Bhatt, Deepak L.; Boer, Jolanda M. A.; Boerwinkle, Eric; Burkley, Ben; Burt, Amber; Chakravarti, Aravinda; Chen, Wei; Cooper-DeHoff, Rhonda M.; Curtis, Sean P.; Dreisbach, Albert; Duggan, David; Ehret, Georg B.; Fabsitz, Richard R.; Fornage, Myriam; Fox, Ervin; Furlong, Clement E.; Gansevoort, Ron T.; Hofker, Marten H.; Hovingh, G. Kees; Kirkland, Susan A.; Kottke-Marchant, Kandice; Kutlar, Abdullah; LaCroix, Andrea Z.; Langaee, Taimour Y.; Li, Yun R.; Lin, Honghuang; Liu, Kiang; Maiwald, Steffi; Malik, Rainer; Murugesan, Gurunathan; Newton-Cheh, Christopher; OConnell, Jeffery R.; Onland-Moret, N. Charlotte; Ouwehand, Willem H.; Palmas, Walter; Penninx, Brenda W.; Pepine, Carl J.; Pettinger, Mary; Polak, Joseph F.; Ramachandran, Vasan S.; Ranchalis, Jane; Redline, Susan; Ridker, Paul M.; Rose, Lynda M.; Scharnag, Hubert; Schork, Nicholas J.; Shimbo, Daichi; Shuldiner, Alan R.; Srinivasan, Sathanur R.; Stolk, Ronald P.; Taylor, Herman A.; Thorand, Barbara; Trip, Mieke D.; van Duijn, Cornelia M.; Verschuren, W. Monique; Wijmenga, Cisca; Winkelmann, Bernhard R.; Wyatt, Sharon; Young, J. Hunter; Boehm, Bernhard O.; Caulfield, Mark J.; Chasman, Daniel I.; Davidson, Karina W.; Doevendans, Pieter A.; FitzGerald, Garret A.; Gums, John G.; Hakonarson, Hakon; Hillege, Hans L.; Illig, Thomas; Jarvik, Gail P.; Johnson, Julie A.; Kastelein, John J. P.; Koenig, Wolfgang; Maerz, Winfried; Mitchell, Braxton D.; Murray, Sarah S.; Oldehinkel, Albertine J.; Rader, Daniel J.; Reilly, Muredach P.; Reiner, Alex P.; Schadt, Eric E.; Silverstein, Roy L.; Snieder, Harold; Stanton, Alice V.; Uitterlinden, Andre G.; van der Harst, Pim; van der Schouw, Yvonne T.; Samani, Nilesh J.; Johnson, Andrew D.; Munroe, Patricia B.; de Bakker, Paul I. W.; Zhu, Xiaofeng; Levy, Daniel; Keating, Brendan J.; Asselbergs, Folkert W.

    2013-01-01

    Blood pressure (BP) is a heritable determinant of risk for cardiovascular disease (CVD). To investigate genetic associations with systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP) and pulse pressure (PP), we genotyped 50 000 single-nucleotide polymorphisms (SNPs) that capture varia

  4. Influence of high-pressure-low-temperature treatment on the inactivation of Bacillus subtilis cells.

    NARCIS (Netherlands)

    T. Shen; G. Urrutia Benet; S. Brul; D. Knorr

    2005-01-01

    High pressure inactivation processes, especially at subzero temperatures, were performed on Bacillus subtilis vegetative cells at various pressure, temperature and time combinations. Whilst atmospheric pressure, lowering the temperature for various periods to as low as 45 -C was found to have minor

  5. LATERAL CEPHALOMETRIC RADIOGRAPHY FOR EVALUATION OF UPPER AIRWAY

    Directory of Open Access Journals (Sweden)

    Miesje Karmiati Purwanegara

    2015-06-01

    Full Text Available The influenced of respiration to dentocraniofacial growth and development is still controversial. The accurate radiologic examination is important factor for proper diagnosis. Deviation of upper airway (i.e. nasopharynx, oropharymx and nasal cavity could be evaluated by lateral and anteroposterior cephalometric projection technique. This paper explains several methods to evaluate upper respiratory tract by lateral radiograph.

  6. The influence of coughing on cerebrospinal fluid pressure in an in vitro syringomyelia model with spinal subarachnoid space stenosis

    Directory of Open Access Journals (Sweden)

    Martin Bryn A

    2009-12-01

    Full Text Available Abstract Background The influence of coughing, on the biomechanical environment in the spinal subarachnoid space (SAS in the presence of a cerebrospinal fluid flow stenosis, is thought to be an important etiological factor in craniospinal disorders, including syringomyelia (SM, Chiari I malformation, and hydrocephalus. The aim of this study was to investigate SAS and syrinx pressures during simulated coughing using in vitro models and to provide information for the understanding of the craniospinal fluid system dynamics to help develop better computational models. Methods Four in vitro models were constructed to be simplified representations of: 1 non-communicating SM with spinal SAS stenosis; 2 non-communicating SM due to spinal SAS stenosis with a distensible spinal column; 3 non-communicating SM post surgical removal of a spinal SAS stenosis; and 4 a spinal SAS stenosis due to spinal trauma. All of the models had a flexible spinal cord. To simulate coughing conditions, an abrupt CSF pressure pulse (~ 5 ms was imposed at the caudal end of the spinal SAS by a computer-controlled pump. Pressure measurements were obtained at 4 cm intervals along the spinal SAS and syrinx using catheter tip transducers. Results Pressure measurements during a simulated cough, showed that removal of the stenosis was a key factor in reducing pressure gradients in the spinal SAS. The presence of a stenosis resulted in a caudocranial pressure drop in the SAS, whereas pressure within the syrinx cavity varied little caudocranially. A stenosis in the SAS caused the syrinx to balloon outward at the rostral end and be compressed at the caudal end. A >90% SAS stenosis did not result in a significant Venturi effect. Increasing compliance of the spinal column reduced forces acting on the spinal cord. The presence of a syrinx in the cord when there was a stenosis in the SAS, reduced pressure forces in the SAS. Longitudinal pressure dissociation acted to suck fluid and tissue

  7. A new removable airway stent

    Directory of Open Access Journals (Sweden)

    Tore Amundsen

    2016-09-01

    Full Text Available Background: Malignant airway obstruction is a feared complication and will most probably occur more frequently in the future because of increasing cancer incidence and increased life expectancy in cancer patients. Minimal invasive treatment using airway stents represents a meaningful and life-saving palliation. We present a new removable airway stent for improved individualised treatment. Methods: To our knowledge, the new airway stent is the world's first knitted and uncovered self-expanding metal stent, which can unravel and be completely removed. In an in vivo model using two anaesthetised and spontaneously breathing pigs, we deployed and subsequently removed the stents by unravelling the device. The procedures were executed by flexible bronchoscopy in an acute and a chronic setting – a ‘proof-of-principle’ study. Results: The new stent was easily and accurately deployed in the central airways, and it remained fixed in its original position. It was easy to unravel and completely remove from the airways without clinically significant complications. During the presence of the stent in the chronic study, granulation tissue was induced. This tissue disappeared spontaneously with the removal. Conclusions: The new removable stent functioned according to its purpose and unravelled easily, and it was completely removed without significant technical or medical complications. Induced granulation tissue disappeared spontaneously. Further studies on animals and humans are needed to define its optimal indications and future use.

  8. Simultaneous influence of hydrostatic pressure and temperature on diamagnetic susceptibility of impurity doped quantum dots under the aegis of noise

    Science.gov (United States)

    Saha, Surajit; Ganguly, Jayanta; Bera, Aindrila; Ghosh, Manas

    2016-11-01

    We explore the diamagnetic susceptibility (DMS) of impurity doped quantum dot (QD) in presence of Gaussian white noise and under the combined influence of hydrostatic pressure (HP) and temperature (T). Presence of noise and also its mode of application discernibly affect the DMS profile. Application of HP and T invites greater delicacies in the observed DMS profiles. However, whereas the interplay between T and noise comes out to be extremely sensitive in fabricating the DMS profile, the pressure-noise interplay appears to be not that much noticeable. Under all conditions of temperature and pressure, the presence of multiplicative noise diminishes the value of DMS in comparison with that in presence of its additive analogue. The present study renders a deep insight into the remarkable role played by the interplay between noise, hydrostatic pressure and temperature in controlling the effective confinement imposed on the system which bears unquestionable relevance.

  9. Neuropeptides control the dynamic behavior of airway mucosal dendritic cells.

    Science.gov (United States)

    Voedisch, Sabrina; Rochlitzer, Sabine; Veres, Tibor Z; Spies, Emma; Braun, Armin

    2012-01-01

    The airway mucosal epithelium is permanently exposed to airborne particles. A network of immune cells patrols at this interface to the environment. The interplay of immune cells is orchestrated by different mediators. In the current study we investigated the impact of neuronal signals on key functions of dendritic cells (DC). Using two-photon microscopic time-lapse analysis of living lung sections from CD11c-EYFP transgenic mice we studied the influence of neuropeptides on airway DC motility. Additionally, using a confocal microscopic approach, the phagocytotic capacity of CD11c(+) cells after neuropeptide stimulation was determined. Electrical field stimulation (EFS) leads to an unspecific release of neuropeptides from nerves. After EFS and treatment with the neuropeptides vasoactive intestinal peptide (VIP) or calcitonin gene-related peptide (CGRP), airway DC in living lung slices showed an altered motility. Furthermore, the EFS-mediated effect could partially be blocked by pre-treatment with the receptor antagonist CGRP(8-37). Additionally, the phagocytotic capacity of bone marrow-derived and whole lung CD11c(+) cells could be inhibited by neuropeptides CGRP, VIP, and Substance P. We then cross-linked these data with the in vivo situation by analyzing DC motility in two different OVA asthma models. Both in the acute and prolonged OVA asthma model altered neuropeptide amounts and DC motility in the airways could be measured. In summary, our data suggest that neuropeptides modulate key features motility and phagocytosis of mouse airway DC. Therefore altered neuropeptide levels in airways during allergic inflammation have impact on regulation of airway immune mechanisms and therefore might contribute to the pathophysiology of asthma.

  10. Ozone production in parallel multichannel dielectric barrier discharge from oxygen and air: the influence of gas pressure

    Science.gov (United States)

    Yuan, Dingkun; Wang, Zhihua; Ding, Can; He, Yong; Whiddon, Ronald; Cen, Kefa

    2016-11-01

    This research aims to investigate the influence of gas pressure (0.1 Mpa-0.2 Mpa) on ozone generation in a parallel multichannel dielectric barrier discharge (DBD) reactor with a narrow gap (0.2 mm). In addition to determining ozone concentration and ozone yield characteristics with gas pressure variation, this paper examines the possible reasons leading to the inconsistency with previous reported results. All the experimental results are plotted on the basis of specific input energy (SIE) in order to conduct the comparison within identical power density. By reviewing the experimental results, the possible cause leading to the inconsistency concerning gas pressure dependences of ozone generation was found using different comparison bases. Results show that ozone generation is slightly suppressed with an increase of gas pressure with an initial increase in SIE. The results of the ozone yield show that an increase of gas pressure would have a favorable effect on ozone production efficiency with an SIE larger than 400 J l-1 in oxygen while ozone yield reaches the maximum at 0.14 Mpa with an SIE larger than 150 J l-1 in air. Increasing gas pressure would lead to a higher critical SIE value at which ozone yield firstly decreases with an increase of SIE both in oxygen and air. The results of nitrogen oxide byproducts show that both NO x byproducts emission and the discharge poisoning effect are suppressed by increasing gas pressure in air plasmas.

  11. Vessel-guided airway tree segmentation

    DEFF Research Database (Denmark)

    Lo, Pechin Chien Pau; Sporring, Jon; Ashraf, Haseem

    2010-01-01

    This paper presents a method for airway tree segmentation that uses a combination of a trained airway appearance model, vessel and airway orientation information, and region growing. We propose a voxel classification approach for the appearance model, which uses a classifier that is trained...... to differentiate between airway and non-airway voxels. This is in contrast to previous works that use either intensity alone or hand crafted models of airway appearance. We show that the appearance model can be trained with a set of easily acquired, incomplete, airway tree segmentations. A vessel orientation...... similarity measure is introduced, which indicates how similar the orientation of an airway candidate is to the orientation of the neighboring vessel. We use this vessel orientation similarity measure to overcome regions in the airway tree that have a low response from the appearance model. The proposed...

  12. [Upper airway obstruction caused by a floppy epiglottis--report of two cases of amyotrophic lateral sclerosis (ALS)].

    Science.gov (United States)

    Ito, Keiko; Chitose, Hiroko; Kobayashi, Asako

    2009-09-01

    The motor system is extensively affected in amyotrophic lateral sclerosis (ALS). Rapid disease progression almost certainly ensures that about half of thsese cases will experience respiratory muscle paralysis to breathe within about five years. We report two cases of ALS involving upper airway obstruction. Fiberoptic laryngoscopy showed floppy epiglottis, tilted posteriorly and horizontally and impacting against the posterior pharyngeal wall during inspiration. Several months later, airway obstruction grew exceedingly worse, and the tilted epiglottis did not return to its vertical resting position. Tracheostomy was conducted during this period. We found that laryngoscopy may be useful in the evaluation of upper airway obstruction, and it may be safer to avoid continuous positive airway pressure.

  13. On locating the obstruction in the human upper airway

    Science.gov (United States)

    Wang, Yong; Elghobashi, S.

    2013-11-01

    The fluid dynamical properties of the air flow in the human upper airway (UA) are not fully understood at present due to the three-dimensional, patient-specific complex geometry of the airway, flow transition from laminar to turbulent and flow-structure interaction during the breathing cycle. One of the major challenges to surgeons is determining the location of the UA obstruction before performing corrective surgeries. It is quite difficult at present to experimentally measure the instantaneous velocity and pressure at specific points in the human airway. On the other hand, direct numerical simulation (DNS) can predict all the flow properties and resolve all its relevant length- and time-scales. We developed a DNS solver with lattice Boltzmann method (LBM), and used it to investigate the flow in two patient-specific UAs reconstructed from CT scan data. Inspiration and expiration flows through these two airways are studied and compared. Pressure gradient-time signals at different locations in the UAs are used to determine the location of the obstruction. This work was supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH).

  14. Airway microbiota and acute respiratory infection in children.

    Science.gov (United States)

    Hasegawa, Kohei; Camargo, Carlos A

    2015-01-01

    Acute respiratory infections (ARIs), such as bronchiolitis and pneumonia, are the leading cause of hospitalization of infants in the US. While the incidence and severity of ARI can vary widely among children, the reasons for these differences are not fully explained by traditional risk factors (e.g., prematurity, viral pathogens). The recent advent of molecular diagnostic techniques has revealed the presence of highly functional communities of microbes inhabiting the human body (i.e., microbiota) that appear to influence development of local and systemic immune response. We propose a 'risk and resilience' model in which airway microbiota are associated with an increased (risk microbiota) or decreased (resilience microbiota) incidence and severity of ARI in children. We also propose that modulating airway microbiota (e.g., from risk to resilience microbiota) during early childhood will optimize airway immunity and, thereby, decrease ARI incidence and severity in children.

  15. Regional aerosol deposition in human upper airways. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Swift, D.L.

    1997-11-01

    During the award period, a number of studies have been carried out related to the overall objective of the project which is to elucidate important factors which influence the upper airway deposition and dose of particles in the size range 0.5 nm - 10 {mu}m, such as particle size, breathing conditions, age, airway geometry, and mode of breathing. These studies are listed below. (1) A high voltage electrospray system was constructed to generate polydispersed 1-10 {mu}m diameter di-ethylhexyl sebacate aerosol for particle deposition studies in nasal casts and in human subjects. (2) The effect of nostril dimensions, nasal passage geometry, and nasal resistance on particle deposition efficiency in forty healthy, nonsmoking adults at a constant flowrate were studied. (3) The effect of nostril dimensions, nasal passage dimensions and nasal resistance on the percentage of particle deposition in the anterior 3 cm of the nasal passage of spontaneously breathing humans were studied. (4) The region of deposition of monodispersed aerosols were studied using replicate casts. (5) Ultrafine aerosol deposition using simulated breath holding path and natural path was compared. (6) An experimental technique was proposed and tested to measure the oral deposition of inhaled ultrafine particles. (7) We have calculated the total deposition fraction of ultrafine aerosols from 5 to 200 n in the extrathoracic airways and in the lung. (8) The deposition fraction of radon progeny in the head airways was studied using several head airway models.

  16. Oxygenation, Ventilation, and Airway Management in Out-of-Hospital Cardiac Arrest: A Review

    Directory of Open Access Journals (Sweden)

    Tomas Henlin

    2014-01-01

    Full Text Available Recently published evidence has challenged some protocols related to oxygenation, ventilation, and airway management for out-of-hospital cardiac arrest. Interrupting chest compressions to attempt airway intervention in the early stages of OHCA in adults may worsen patient outcomes. The change of BLS algorithms from ABC to CAB was recommended by the AHA in 2010. Passive insufflation of oxygen into a patent airway may provide oxygenation in the early stages of cardiac arrest. Various alternatives to tracheal intubation or bag-mask ventilation have been trialled for prehospital airway management. Simple methods of airway management are associated with similar outcomes as tracheal intubation in patients with OHCA. The insertion of a laryngeal mask airway is probably associated with worse neurologically intact survival rates in comparison with other methods of airway management. Hyperoxemia following OHCA may have a deleterious effect on the neurological recovery of patients. Extracorporeal oxygenation techniques have been utilized by specialized centers, though their use in OHCA remains controversial. Chest hyperinflation and positive airway pressure may have a negative impact on hemodynamics during resuscitation and should be avoided. Dyscarbia in the postresuscitation period is relatively common, mainly in association with therapeutic hypothermia, and may worsen neurological outcome.

  17. Oxygenation, ventilation, and airway management in out-of-hospital cardiac arrest: a review.

    Science.gov (United States)

    Henlin, Tomas; Michalek, Pavel; Tyll, Tomas; Hinds, John D; Dobias, Milos

    2014-01-01

    Recently published evidence has challenged some protocols related to oxygenation, ventilation, and airway management for out-of-hospital cardiac arrest. Interrupting chest compressions to attempt airway intervention in the early stages of OHCA in adults may worsen patient outcomes. The change of BLS algorithms from ABC to CAB was recommended by the AHA in 2010. Passive insufflation of oxygen into a patent airway may provide oxygenation in the early stages of cardiac arrest. Various alternatives to tracheal intubation or bag-mask ventilation have been trialled for prehospital airway management. Simple methods of airway management are associated with similar outcomes as tracheal intubation in patients with OHCA. The insertion of a laryngeal mask airway is probably associated with worse neurologically intact survival rates in comparison with other methods of airway management. Hyperoxemia following OHCA may have a deleterious effect on the neurological recovery of patients. Extracorporeal oxygenation techniques have been utilized by specialized centers, though their use in OHCA remains controversial. Chest hyperinflation and positive airway pressure may have a negative impact on hemodynamics during resuscitation and should be avoided. Dyscarbia in the postresuscitation period is relatively common, mainly in association with therapeutic hypothermia, and may worsen neurological outcome.

  18. Influence of embedding parameters and noise in center of pressure recurrence quantification analysis.

    Science.gov (United States)

    Hasson, Christopher J; Van Emmerik, Richard E A; Caldwell, Graham E; Haddad, Jeffrey M; Gagnon, Jeff L; Hamill, Joseph

    2008-04-01

    Recurrence quantification analysis (RQA) can extract the dynamics of postural control from center of pressure (CoP) data by quantifying the system's repeatability, complexity, and local dynamic stability through several variables. Computation of these variables requires the selection of suitable embedding parameters for state space reconstruction (i.e. time delay and embedding dimension); however, it is unclear how the parameters influence RQA variables when examining noisy CoP data. This study evaluated the sensitivity of RQA variables to embedding parameter values and noise level, and assessed methods of selecting embedding parameters for CoP data. Five healthy male subjects maintained quiet stance for 30s while the anterior-posterior CoP was measured. The effect of noise was evaluated by adding uniform white noise of increasing amplitude to the raw CoP signal. The magnitude of all RQA variables decreased with increasing noise amplitude for all subjects. A sensitivity analysis was performed by systematically altering the embedding parameters for the raw data with and without a selected level of added noise. The key result was that, for all subjects, the RQA variables were sensitive to the embedding parameter values and the level of noise in the CoP data. Finally, the performance of false nearest neighbors and average displacement algorithms for choosing embedding parameters was evaluated. Both methods gave clear and consistent results for all subjects with either raw or noisy data. The results suggest that careful selection of embedding parameters is essential when using RQA to examine postural control based on noisy CoP data.

  19. Influence of layer charge and charge location on the swelling pressure of dioctahedral smectites

    Science.gov (United States)

    Sun, Linlin; Ling, Chian Ye; Lavikainen, Lasse P.; Hirvi, Janne T.; Kasa, Seppo; Pakkanen, Tapani A.

    2016-07-01

    Swelling pressure of dioctahedral smectites in the montmorillonite - beidellite series was investigated by molecular dynamics simulations. The pressure was found to correlate inversely with the magnitude of the layer charge in the range of -0.5 to -1.0 per unit cell. The beidellite type smectites were found to have lower swelling pressure than the montmorillonite type smectites. A clear effect of the type of interlayer cations on the swelling pressure was found. The sodium smectites sustained significant pressure even at longer interlayer distances, while in calcium smectites the pressure decreased soon after the initial swelling. The simulation results are in good agreement with experimental observations and provide a tool for predicting macroscopic swelling behavior in smectites.

  20. Airway management using a supraglottic airway device without endotracheal intubation for positive ventilation of anaesthetized rats.

    Science.gov (United States)

    Cheong, S H; Lee, J H; Kim, M H; Cho, K R; Lim, S H; Lee, K M; Park, M Y; Yang, Y I; Kim, D K; Choi, C S

    2013-04-01

    Endotracheal intubation is often necessary for positive pressure ventilation of rats during open thoracic surgery. Since endotracheal intubation in rats is technically difficult and is associated with numerous complications, many techniques using various devices have been described in the scientific literature. In this study, we compared the effectiveness of airway management of a home-made supraglottic airway device (SAD), which is cheap to fabricate and easy to place with that of an endotracheal intubation tube in enflurane-anaesthetized rats. Twenty male Sprague-Dawley rats (200-300 g) were randomly assigned to two equal groups for positive pressure mechanical ventilation using either the SAD or an endotracheal intubation tube. The carotid artery of each rat was cannulated for continuous blood pressure measurements and obtaining blood samples for determination of oxygen tension, carbon dioxide tension, and blood acidity before, during and after SAD placement or endotracheal intubation. Proper placement of the SAD was confirmed by observing chest wall movements that coincided with the operation of the mechanical ventilator. No complications and adverse events were encountered in the rats in which the SAD was placed, during SAD placement and immediate removal, during their mechanical ventilation through the SAD, and one week after SAD removal. From the results of blood gas analyses, we conclude that anaesthetized rats can be successfully ventilated using an SAD for open thoracic surgery.

  1. Influence of gas pressure state on the motion parameters of coal-gas flow in the outburst hole

    Institute of Scientific and Technical Information of China (English)

    SUN Dong-ling; LIANG Yun-pei; MIAO Fa-tian

    2007-01-01

    Carried on the one-dimensional analysis to the motion state of coal-gas flow in the outburst hole, and deduced the relational expression between the motion parameters (containing of velocity, flow rate and density etc.) of bursting coal-gas flow and gas pressure in the hole, then pointed out the critical state change of coal-gas flow under different pressure conditions which had the very tremendous influence on both stability and destructiveness of the entire coal and gas outburst system. The mathematical processing and results of one-dimensional flow under the perfect condition are simple and explicit in this paper, which has the certain practical significance.

  2. The Influence of Proximity to City Parks on Blood Pressure in Early Pregnancy

    OpenAIRE

    Grazuleviciene, Regina; Dedele, Audrius; Danileviciute, Asta; Vencloviene, Jone; Grazulevicius, Tomas; Andrusaityte, Sandra; Uzdanaviciute, Inga; Nieuwenhuijsen, Mark J.

    2014-01-01

    This study investigated the effect of proximity to city parks on blood pressure categories during the first trimester of pregnancy. This cross-sectional study included 3,416 female residents of the city of Kaunas, Lithuania, who were enrolled in the FP7 PHENOTYPE project study. The women were classified into four blood pressure categories: optimal, normal, high-normal blood pressure, and hypertension. Multinomial regression models were used to investigate the association between three women’s...

  3. The Influence of Proximity to City Parks on Blood Pressure in Early Pregnancy

    OpenAIRE

    2014-01-01

    This study investigated the effect of proximity to city parks on blood pressure categories during the first trimester of pregnancy. This cross-sectional study included 3,416 female residents of the city of Kaunas, Lithuania, who were enrolled in the FP7 PHENOTYPE project study. The women were classified into four blood pressure categories: optimal, normal, high-normal blood pressure, and hypertension. Multinomial regression models were used to investigate the association between three wome...

  4. Comparative Study of laryngeal mask airway Supreme and laryngeal mask airway Classic in paralyzed patients

    OpenAIRE

    2016-01-01

    Aim and Objectives: The present study was undertaken to compare the LMA Classic with LMA Supreme in assessing the ease of insertion, number of attempts, time for insertion, any unwanted responses, stability of device, peak airway pressure, leak volume and leak fraction and postoperative complications.Methods: A total of 274 patients of ASA grade 1 and 2 were included in the study and divided into two groups with 137 patients in each group: the LMA Classic group (group C) and LMA Supreme group...

  5. The Influence of Proximity to City Parks on Blood Pressure in Early Pregnancy

    Directory of Open Access Journals (Sweden)

    Regina Grazuleviciene

    2014-03-01

    Full Text Available This study investigated the effect of proximity to city parks on blood pressure categories during the first trimester of pregnancy. This cross-sectional study included 3,416 female residents of the city of Kaunas, Lithuania, who were enrolled in the FP7 PHENOTYPE project study. The women were classified into four blood pressure categories: optimal, normal, high-normal blood pressure, and hypertension. Multinomial regression models were used to investigate the association between three women’s groups with respect to the residence distances from city parks (300, >300–1,000, and >1,000 m and four blood pressure categories. When using the optimal blood pressure as the reference group, the crude and adjusted odds ratios (OR for normal blood pressure and for high-normal blood pressure proved to be statistically significantly higher after the inclusion of the selected covariates into the regression analysis. The probability of normal blood pressure increased by 9%, and that of high-normal blood pressure—by 14% for every 300 m increase in the distance to green spaces. The findings of this study suggest a beneficial impact of nearby city parks on blood pressure amongst 20- to 45-year-old women. This relationship has important implications for the prevention of hypertension and the reduction of hypertension-related morbidity.

  6. Simulation of turbulent airflow using a CT based upper airway model of a racehorse.

    Science.gov (United States)

    Rakesh, Vineet; Datta, Ashim K; Ducharme, Normand G; Pease, Anthony P

    2008-06-01

    Computational model for airflow through the upper airway of a horse was developed. Previous flow models for human airway do not hold true for horses due to significant differences in anatomy and the high Reynolds number of flow in the equine airway. Moreover, models that simulate the entire respiratory cycle and emphasize on pressures inside the airway in relation to various anatomical diseases are lacking. The geometry of the airway was created by reconstructing images obtained from computed tomography scans of a thoroughbred racehorse. Different geometries for inhalation and exhalation were used for the model based on the difference in the nasopharynx size during the two phases of respiration. The Reynolds averaged Navier-Stokes equations were solved for the isothermal flow with the standard k-epsilon model for turbulence. Transient pressure boundary conditions for the entire breathing cycle were obtained from past experimental studies on live horses. The flow equations were solved in a commercial finite volume solver. The flow rates, computed based on the applied pressure conditions, were compared to experimentally measured flow rates for model validation. Detailed analysis of velocity, pressure, and turbulence characteristics of the flow was done. Velocity magnitudes at various slices during inhalation were found to be higher than corresponding velocity magnitudes during exhalation. The front and middle parts of the nasopharynx were found to have minimum intraluminal pressure in the airway during inhalation. During exhalation, the pressures in the soft palate were higher compared to those in the larynx, epiglottis, and nasopharynx. Turbulent kinetic energy was found to be maximum at the entry to the airway and gradually decreased as the flow moved inside the airway. However, turbulent kinetic energy increased in regions of the airway with abrupt change in area. Based on the analysis of pressure distribution at different sections of the airway, it was concluded

  7. Numerical simulation of soft palate movement and airflow in human upper airway by fluid-structure interaction method

    Science.gov (United States)

    Sun, Xiuzhen; Yu, Chi; Wang, Yuefang; Liu, Yingxi

    2007-08-01

    In this paper, the authors present airflow field characteristics of human upper airway and soft palate movement attitude during breathing. On the basis of the data taken from the spiral computerized tomography images of a healthy person and a patient with Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS), three-dimensional models of upper airway cavity and soft palate are reconstructed by the method of surface rendering. Numerical simulation is performed for airflow in the upper airway and displacement of soft palate by fluid-structure interaction analysis. The reconstructed three-dimensional models precisely preserve the original configuration of upper airways and soft palate. The results of the pressure and velocity distributions in the airflow field are quantitatively determined, and the displacement of soft palate is presented. Pressure gradients of airway are lower for the healthy person and the airflow distribution is quite uniform in the case of free breathing. However, the OSAHS patient remarkably escalates both the pressure and velocity in the upper airway, and causes higher displacement of the soft palate. The present study is useful in revealing pathogenesis and quantitative mutual relationship between configuration and function of the upper airway as well as in diagnosing diseases related to anatomical structure and function of the upper airway.

  8. Numerical simulation of soft palate movement and airflow in human upper airway by fluid-structure interaction method

    Institute of Scientific and Technical Information of China (English)

    Xiuzhen Sun; Chi Yu; Yuefang Wang; Yingxi Liu

    2007-01-01

    In this paper, the authors present airflow field characteristics of human upper airway and soft palate move-ment attitude during breathing. On the basis of the data taken from the spiral computerized tomography images of a healthy person and a patient with Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS), three-dimensional models of upper air-way cavity and soft palate are reconstructed by the method of surface rendering. Numerical simulation is performed for airflow in the upper airway and displacement of soft palate by fluid-structure interaction analysis. The reconstructed three-dimensional models precisely preserve the original config-uration of upper airways and soft palate. The results of the pressure and velocity distributions in the airflow field are quantitatively determined, and the displacement of soft palate is presented. Pressure gradients of airway are lower for the healthy person and the airflow distribution is quite uniform in the case of free breathing. However, the OSAHS patient remarkably escalates both the pressure and velocity in the upper airway, and causes higher displacement of the soft palate. The present study is useful in revealing pathogenesis and quantitative mutual relationship between configuration and function of the upper airway as well as in diagnosing diseases related to anatomical structure and function of the upper airway.

  9. Influence of hydrostatic pressure on superconducting properties of niobium thin film

    Energy Technology Data Exchange (ETDEWEB)

    Pristáš, Gabriel; Gabáni, Slavomír; Gažo, Emil [Centre of Low Temperature Physics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Košice (Slovakia); Komanický, Vladimír; Orendáč, Matúš [Centre of Low Temperature Physics, Faculty of Science, P. J. Šafárik University, Park Angelinum 9, SK-04154 Košice (Slovakia); You, Hoydoo [Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2014-04-01

    We have studied superconducting properties of niobium thin films under hydrostatic pressures up to 3 GPa. The films with thickness of 100 nm were prepared in the high vacuum DC magnetron sputtering system (with critical temperature TC = 8.95 K at ambient pressure). The produced high quality films have been characterized using electrical resistivity and magnetization measurements, X-ray diffraction, and atomic force microscope imaging. We have observed increase of TC with increasing value of applied pressure (dTC/dp = 73 mK/GPa) up to 3 GPa. This observation is different to pressure effect observed on bulk sample of Nb. In this paper we are discussing the origin of this discrepancy. - Highlights: • We have studied superconducting properties of niobium thin films under pressure. • The 100 nm thick films were prepared in DC magnetron sputtering system. • We have observed different behavior of T{sub C} for thin film and for bulk sample.

  10. Influence of Post-treatment Methods on Pressure Change of Filter Bag

    Directory of Open Access Journals (Sweden)

    Yihua Yin

    2016-01-01

    Full Text Available The PPS needle-punched non-woven filters with different post-treatments were studied by filter testing system. The pressure drop was measured at various filtration velocity, dust deposition time and the temperature during the experiment; and the effect of dust-cleaning as the consequence of pressure of filter bag was measured. The results showed that post-treatments transformed the surfaces of filters, and the dust formation differed greatly. Excessively high filtration velocity decreased the peak pressure in the process of dust-cleaning. The pressure of filter bag was increased as the dust layers were thickened. The higher temperature in filtration rose the peak pressure of filter bag, but decreased the rate of rising.

  11. The influence of electrode configuration on light emission profiles and electrical characteristics of an atmospheric-pressure plasma jet

    Science.gov (United States)

    Maletić, Dejan; Puač, Nevena; Malović, Gordana; Đorđević, Antonije; Petrović, Zoran Lj

    2017-04-01

    In this paper we focus on the influence of the type of electrodes, their dimensions and inter-electrode gap on the formation of a helium plasma jet. Plasma emission profiles are recorded by an ICCD camera simultaneously with volt–ampere characteristics for three different copper electrode configurations. The delivered power was up to 6.5 W, but it may be set and controlled to 0.1 W. This study shows how the electrode configuration shapes and controls temporal and spatial plasma development as well as electrical characteristics of an atmospheric pressure plasma jet. It is shown that, in our system, the width of the grounded electrode has no significant influence on the formation and properties of pulsed atmospheric-pressure streamers (PAPS) outside the tube, while the width of the powered electrode is crucial in their formation.

  12. Influence of oxygen partial pressure on crystallization behaviour and high-temperature stability of stone wool fibres

    Energy Technology Data Exchange (ETDEWEB)

    Kaasgaard, M.; Jacobsen, P.A.L.; Yue Yuanzheng [Aalborg Univ. (Denmark). Section of Chemistry

    2005-04-01

    The influence of oxygen partial pressure on the redox state of the iron in stone wool is studied using thermogravimetry (TG). The thermal response of the stone wool is measured using differential scanning calorimetry (DSC). The high-temperature stability of stone wool depending on the oxygen partial pressure is observed using scanning electron microscopy (SEM). It is confirmed that the oxidation of Fe{sup 2+} to Fe{sup 3+} is responsible for the high-temperature stability of stone wool. Even a minor increase in oxygen partial pressure can considerably alter the crystallization behaviour and enhance the high-temperature stability of the stone wool. The origin for that is discussed. (orig.)

  13. Influence of the compaction pressure on the electrochemical impedance spectroscopy response of the AB{sub 5}-type electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.E.; Castro, E.B.; Visintin, A. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, UNLP, CCT La Plata-CONICET, CC 16, Suc. 4 (1900) La Plata (Argentina)

    2010-06-15

    AB5-type alloys are commercially used in electrodes for rechargeable batteries due to their high capacity, good kinetics for the hydriding/dehydriding reactions and long useful life (cycling resistance). The aim of this work is to study, using electrochemical impedance spectroscopy, the influence of the preparation compaction pressure, on the performance of the electrode. The results show the effect of increasing compaction pressure on the interfacial and active areas, and on the reduction of the contact resistance between particles. In this study a pressure range for optimal electrode behavior is determined. These results agree with behavior predicted by the proposed physicochemical model and with experimental results reported in previous works, using others electrochemical techniques. (author)

  14. A RANDOMIZED CROSSOVER COMPARISON OF THE LARYNGEAL MASK AIRWAY PROSEAL AND LARYNGEAL MASK AIRWAY SUPREME IN ANESTHETIZED ADULT PATIENTS

    Directory of Open Access Journals (Sweden)

    Vinayaka

    2015-10-01

    Full Text Available BACKGROUND : Newer supraglottic airway devices have been recently introduced, motivated by the need for a single use equivalent to the reusable LMA Proseal. LMA Supreme is a new single use laryngeal mask airway with gastric access providing an easy, reliable airway and good airway seal. The objectives of the present study were to compare LMA Proseal and LMA Supreme for ease of insertion, oropharyn geal leak pressure and fibre - optic position in anesthetized adult patients. MATERIAL AND METHODS : We conducted a prospective randomized study in 60 ASA grade I and II adult patients posted for elective surgeries under general anesthesia. Both devices were inserted into each patient in random order. Two attempts were allowed. Digital insertion was used for the first attempt and guided insertion for the second attempt. The ease of insertion, oropharyngeal leak pressure and fibre - optic position were determined . RESULTS : First attempt and overall success of insertion were similar (LMA Proseal 93.33% and 100%; LMA Supreme 96.66% and 100%. Guided insertion was always successful following failed digital insertion. There was no difference in the mean duration of insertion for both the devices (23.92±1.44 vs 23.44±1.72seconds. The mean oropharyngeal leak pressure was significantly higher for the LMA Proseal than the LMA Supreme (23.24 vs 19.37cm of H 2 O (p<0.05. The fibre - optic view of the glottis was similar for both the devices. CONCLUSION : In this study, the ease of insertion and fibre - optic position were similar for the LMA Proseal and LMA Supreme, but oropharyngeal leak pressure is higher for the LMA Proseal. The LMA Proseal provides a more effective seal tha n LMA Supreme for positive pressure ventilation.

  15. Treating asthma means treating airway smooth muscle cells

    NARCIS (Netherlands)

    Zuyderduyn, S; Sukkar, M B; Fust, A; Dhaliwal, S; Burgess, J K

    2008-01-01

    Asthma is characterised by airway hyperresponsiveness, airway inflammation and airway remodelling. Airway smooth muscle cells are known to be the main effector cells of airway narrowing. In the present paper, studies will be discussed that have led to a novel view of the role of airway smooth muscle

  16. A joint computational respiratory neural network-biomechanical model for breathing and airway defensive behaviors

    Directory of Open Access Journals (Sweden)

    Russell eO'Connor

    2012-07-01

    Full Text Available Data-driven computational neural network models have been used to study mechanisms for generating the motor patterns for breathing and breathing related behaviors such as coughing. These models have commonly been evaluated in open loop conditions or with feedback of lung volume simply represented as a filtered version of phrenic motor output. Limitations of these approaches preclude assessment of the influence of mechanical properties of the musculoskeletal system and motivated development of a biomechanical model of the respiratory muscles, airway, and lungs using published measures from human subjects. Here we describe the model and some aspects of its behavior when linked to a computational brainstem respiratory network model for breathing and airway defensive behavior composed of discrete integrate and fire populations. The network incorporated multiple circuit paths and operations for tuning inspiratory drive suggested by prior work. Results from neuromechanical system simulations included generation of a eupneic-like breathing pattern and the observation that increased respiratory drive and operating volume result in higher peak flow rates during cough, even when the expiratory drive is unchanged, or when the expiratory abdominal pressure is unchanged. Sequential elimination of the model’s sources of inspiratory drive during cough also suggested a role for disinhibitory regulation via tonic expiratory neurons, a result that was subsequently supported by an analysis of in vivo data. Comparisons with antecedent models, discrepancies with experimental results, and some model limitations are noted.

  17. Effects of feeding sunflower oil or seal blubber oil to horses with recurrent airway obstruction

    Science.gov (United States)

    Khol-Parisini, Annabella; van den Hoven, René; Leinker, Sandra; Hulan, Howard W.; Zentek, Juergen

    2007-01-01

    A crossover feeding trial was performed with 9 horses suffering from recurrent airway obstruction (RAO). The study aimed to determine whether ingestion of sunflower oil (SFO), rich in linoleic acid, or seal blubber oil (SBO), a source of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs), changes the fatty acid (FA) ratios in plasma and leukocyte membrane phospholipids (PLs) or the leukocyte numbers or proportions of cell types in the airways. We also investigated diet-related changes in respiratory rate, maximum change in pleural pressure (ΔPplmax), dynamic compliance (Cdyn), and pulmonary resistance (RL). Each animal was fed hay and oats supplemented with 320 mg/kg body weight (BW) of either SFO or SBO for 10 wk. Before and after the feeding periods, we performed FA analyses, cytologic testing of the pulmonary epithelial lining fluid (PELF), clinical scoring, and pulmonary function testing. The results demonstrated that supplementary FAs were readily ingested and incorporated into leukocyte cell membranes. The n-6:n-3 FA ratios in plasma and leukocyte PLs were reduced after SBO supplementation, as were the PELF leukocyte counts (P < 0.05). On the other hand, pulmonary function and clinical signs were not markedly changed by the different dietary FAs. These results indicate a possible influence of dietary n-3 PUFAs on the pulmonary inflammation of horses with RAO. Further studies are warranted to address effects on inflammatory mediators and clinical outcome. PMID:17193883

  18. 管道水击压力的影响因素%Influence factors of water hammer pressure in pipeline

    Institute of Scientific and Technical Information of China (English)

    张艳玲

    2015-01-01

    本文综合分析了流速变化和阀门的不同关闭特性对管道水击压力的影响,从而为水击防护措施提供了一定的理论依据。%This paper reviews the influence of flow-rate change and valve closing characteristics on water hammer pressure in pipeline to provide a theoretical basis for water hammer protection.

  19. The influence of patient's consciousness regarding high blood pressure and patient's attitude in face of disease controlling medicine intake

    Directory of Open Access Journals (Sweden)

    Maria Aparecida A Moura Strelec

    2003-10-01

    Full Text Available OBJECTIVE: To assess the relation between blood pressure control and the following: the Morisky-Green test, the patient's consciousness regarding high blood pressure, the patient's attitude in face of medicine intake, the patient's attendance at medical consultations, and the subjective physician's judgment. METHODS: We studied 130 hypertensive patients with the following characteristics: 73% females, 60±11 years, 58% married, 70% white, 45% retired, 45% with incomplete elementary schooling, 64% had a familial income of 1 to 3 minimum wages, body mass index of 30±7 kg/m², consciousness regarding the disease for a mean period of 11±9.5 years, and mean treatment duration of 8 ±7 years. RESULTS: Only 35% of the hypertensive individuals had blood pressure under control and a longer duration of treatment (10±7 vs 7±6.5 years; P<0.05. The retiree predominated. The result of the Morisky-Green test did not relate to blood pressure control. In evaluating the attitude in face of medicine intake, the controlled patients achieved significantly higher scores than did the noncontrolled patients (8±1.9 vs 7 ±2, P<0.05. The hypertensive patients had higher levels of consciousness regarding their disease and its treatment, and most (70% patients attended 3 or 4 medical consultations, which did not influence blood pressure control. The physicians attributed significantly higher scores regarding adherence to treatment to controlled patients (6±0.8 vs 5±1.2; P<0.05. CONCLUSION: Consciousness regarding the disease, the Morisky-Green test, and attendance to medical consultations did not influence blood pressure control.

  20. Curing Pressure Influence of Out-of-Autoclave Processing on Structural Composites for Commercial Aviation

    Directory of Open Access Journals (Sweden)

    Vasileios M. Drakonakis

    2013-01-01

    Full Text Available Autoclaving is a process that ensures the highest quality of carbon fiber reinforced polymer (CFRP composite structures used in aviation. During the autoclave process, consolidation of prepreg laminas through simultaneous elevated pressure and temperature results in a uniform high-end material system. This work focuses on analyzing in a fundamental way the applications of pressure and temperature separately during prepreg consolidation. A controlled pressure vessel (press-clave has been designed that applies pressure during the curing process while the temperature is being applied locally by heat blankets. This vessel gives the ability to design manufacturing processes with different pressures while applying temperature at desired regions of the composite. The pressure role on the curing extent and its effect on the interlayer region are also tested in order to evaluate the consolidation of prepregs to a completely uniform material. Such studies may also be used to provide insight into the morphology of interlayer reinforcement concepts, which are widely used in the featherweight composites. Specimens manufactured by press-clave, which separates pressure from heat, are analytically tested and compared to autoclaved specimens in order to demonstrate the suitability of the press-clave to manufacture high-quality composites with excessively reduced cost.

  1. Airway surface liquid volume expansion induces rapid changes in amiloride-sensitive Na+ transport across upper airway epithelium-Implications concerning the resolution of pulmonary edema

    Science.gov (United States)

    Azizi, Fouad; Arredouani, Abdelilah; Mohammad, Ramzi M

    2015-01-01

    During airway inflammation, airway surface liquid volume (ASLV) expansion may result from the movement of plasma proteins and excess liquid into the airway lumen due to extravasation and elevation of subepithelial hydrostatic pressure. We previously demonstrated that elevation of submucosal hydrostatic pressure increases airway epithelium permeability resulting in ASLV expansion by 500 μL cm−2 h−1. Liquid reabsorption by healthy airway epithelium is regulated by active Na+ transport at a rate of 5 μL cm−2 h−1. Thus, during inflammation the airway epithelium may be submerged by a large volume of luminal liquid. Here, we have investigated the mechanism by which ASLV expansion alters active epithelial Na+ transport, and we have characterized the time course of the change. We used primary cultures of tracheal airway epithelium maintained under air interface (basal ASLV, depth is 7 ± 0.5 μm). To mimic airway flooding, ASLV was expanded to a depth of 5 mm. On switching from basal to expanded ASLV conditions, short-circuit current (Isc, a measure of total transepithelial active ion transport) declined by 90% with a half-time (t1/2) of 1 h. 24 h after the switch, there was no significant change in ATP concentration nor in the number of functional sodium pumps as revealed by [3H]-ouabain binding. However, amiloride-sensitive uptake of 22Na+ was reduced by 70% upon ASLV expansion. This process is reversible since after returning cells back to air interface, Isc recovered with a t1/2 of 5–10 h. These results may have important clinical implications concerning the development of Na+ channels activators and resolution of pulmonary edema. PMID:26333829

  2. Multiscale Vessel-guided Airway Tree Segmentation

    DEFF Research Database (Denmark)

    Lo, Pechin Chien Pau; Sporring, Jon; de Bruijne, Marleen

    2009-01-01

    that is trained to differentiate between airway and non-airway voxels. Vessel and airway orientation information are used in the form of a vessel orientation similarity measure, which indicates how similar the orientation of the an airway candidate is to the orientation of the neighboring vessel. The method...... is evaluated within EXACT’09 on a diverse set of CT scans. Results show a favorable combination of a relatively large portion of the tree detected correctly with very few false positives....

  3. The influence of pressure on the intrinsic dissolution rate of amorphous indomethacin

    DEFF Research Database (Denmark)

    Löbmann, Korbinian; Flouda, Konstantina; Qiu, Danwen;

    2014-01-01

    of different compression pressures on the IDR was determined from powder compacts of amorphous (ball-milling) indomethacin (IND), a glass solution of IND and poly(vinylpyrrolidone) (PVP) and crystalline IND. Solid state properties were analyzed with X-ray powder diffraction (XRPD) and the final compacts were......, compression pressure had an impact on the IDR of pure amorphous IND compacts. Above a critical compression pressure, amorphous particles sintered to form a single compact with dissolution properties similar to quench-cooled disc and crystalline IND compacts. In such a case, the apparent dissolution advantage...

  4. Postural influence on intracranial and cerebral perfusion pressure in ambulatory neurosurgical patients

    DEFF Research Database (Denmark)

    Petersen, Lonnie Grove; Petersen, Johan Casper Grove; Andresen, Morten;

    2016-01-01

    We evaluated postural effects on intracranial pressure (ICP) and cerebral perfusion pressure (CPP: mean arterial pressure (MAP) - ICP) in neurosurgical patients undergoing 24-hour ICP monitoring as part of their diagnostic workup. We identified 9 patients (5 women, age 44±20 yrs.; mean±SD) who were...... "as normal as possible" i.e. without indication for neurosurgical intervention (e.g. focal lesions, global edema, abnormalities in ICP-profile or cerebrospinal fluid dynamics). ICP (tip-transducer probe, Raumedic) in the brain parenchyma (N=7) or in the lateral ventricles (N=2) and cardiovascular...

  5. Influence of Hot Plasma Pressure on Global Structure of Saturn's Magnetodisk

    CERN Document Server

    Achilleos, N; Arridge, C S; Sergis, N; Wilson, R J; Thomsen, M F; Coates, A J

    2010-01-01

    Using a model of force balance in Saturn's disk-like magnetosphere, we show that variations in hot plasma pressure can change the magnetic field configuration. This effect changes (i) the location of the magnetopause, even at fixed solar wind dynamic pressure, and (ii) the magnetic mapping between ionosphere and disk. The model uses equatorial observations as a boundary condition-we test its predictions over a wide latitude range by comparison with a Cassini high-inclination orbit of magnetic field and hot plasma pressure data. We find reasonable agreement over time scales larger than the period of Saturn kilometric radiation (also known as the camshaft period).

  6. Influence of hot plasma pressure on the global structure of Saturn’s magnetodisk

    Science.gov (United States)

    Achilleos, N.; Guio, P.; Arridge, C. S.; Sergis, N.; Wilson, R. J.; Thomsen, M. F.; Coates, A. J.

    2010-10-01

    Using a model of force balance in Saturn's disk-like magnetosphere, we show that variations in hot plasma pressure can change the magnetic field configuration. This effect changes (i) the location of the magnetopause, even at fixed solar wind dynamic pressure, and (ii) the magnetic mapping between ionosphere and disk. The model uses equatorial observations as a boundary condition—we test its predictions over a wide latitude range by comparison with a Cassini high-inclination orbit of magnetic field and hot plasma pressure data. We find reasonable agreement over time scales larger than the period of Saturn kilometric radiation (also known as the camshaft period).

  7. Mouth-opening increases upper-airway collapsibility without changing resistance during midazolam sedation.

    Science.gov (United States)

    Ayuse, T; Inazawa, T; Kurata, S; Okayasu, I; Sakamoto, E; Oi, K; Schneider, H; Schwartz, A R

    2004-09-01

    Sedative doses of anesthetic agents affect upper-airway function. Oral-maxillofacial surgery is frequently performed on sedated patients whose mouths must be as open as possible if the procedures are to be accomplished successfully. We examined upper-airway pressure-flow relationships in closed mouths, mouths opened moderately, and mouths opened maximally to test the hypothesis that mouth-opening compromises upper-airway patency during midazolam sedation. From these relationships, upper-airway critical pressure (Pcrit) and upstream resistance (Rua) were derived. Maximal mouth-opening increased Pcrit to -3.6 +/- 2.9 cm H2O compared with -8.7 +/- 2.8 (p = 0.002) for closed mouths and -7.2 +/- 4.1 (p = 0.038) for mouths opened moderately. In contrast, Rua was similar in all three conditions (18.4 +/- 6.6 vs. 17.7 +/- 7.6 vs. 21.5 +/- 11.6 cm H2O/L/sec). Moreover, maximum mouth-opening produced an inspiratory airflow limitation at atmosphere that was eliminated when nasal pressure was adjusted to 4.3 +/- 2.7 cm H2O. We conclude that maximal mouth-opening increases upper-airway collapsibility, which contributes to upper-airway obstruction at atmosphere during midazolam sedation.

  8. Pharmacogenetics, pharmacogenomics and airway disease

    Directory of Open Access Journals (Sweden)

    Hall Ian P

    2001-11-01

    Full Text Available Abstract The availability of a draft sequence for the human genome will revolutionise research into airway disease. This review deals with two of the most important areas impinging on the treatment of patients: pharmacogenetics and pharmacogenomics. Considerable inter-individual variation exists at the DNA level in targets for medication, and variability in response to treatment may, in part, be determined by this genetic variation. Increased knowledge about the human genome might also permit the identification of novel therapeutic targets by expression profiling at the RNA (genomics or protein (proteomics level. This review describes recent advances in pharmacogenetics and pharmacogenomics with regard to airway disease.

  9. Influence of headspace pressure on methane production in Biochemical Methane Potential (BMP) tests.

    Science.gov (United States)

    Valero, David; Montes, Jesús A; Rico, José Luis; Rico, Carlos

    2016-02-01

    The biochemical methane potential test is the most commonly applied method to determine methane production from organic wastes. One of the parameters measured is the volume of biogas produced which can be determined manometrically by keeping the volume constant and measuring increases in pressure. In the present study, the effect of pressure accumulation in the headspace of the reactors has been studied. Triplicate batch trials employing cocoa shell, waste coffee grounds and dairy manure as substrates have been performed under two headspace pressure conditions. The results obtained in the study showed that headspace overpressures higher than 600mbar affected methane production for waste coffee grounds. On the contrary, headspace overpressures within a range of 600-1000mbar did not affect methane production for cocoa shell and dairy manure. With the analyses performed in the present work it has not been possible to determine the reasons for the lower methane yield value obtained for the waste coffee grounds under high headspace pressures.

  10. Influence of Injection and Cavity Pressure on the Demoulding Force in Micro-Injection Moulding

    DEFF Research Database (Denmark)

    Griffiths, C.A.; Dimov, S.S.; Scholz, S.G.

    2014-01-01

    of four process parameters, melt temperature, mould temperature, holding pressure, and injection speed, employing the design of experiment approach. In addition, the results obtained using different combinations of process parameters were analyzed to identify the best processing conditions in regards...

  11. Insiders and Outsiders: The Politics of Pressure Group Influence on Bureaucracy

    Science.gov (United States)

    Peters, B. Guy

    1977-01-01

    Four categories of interaction between pressure groups and bureaucracy are developed, and the extent and types of effects of each on policy are examined. The four types of interaction are legitimate, clientela, parantela, and illegitimate. (Author/IRT)

  12. Influence of temporal pressure on anticipatory postural control of medio-lateral stability during rapid leg flexion.

    Science.gov (United States)

    Yiou, E; Hussein, T; Larue, J

    2012-03-01

    During leg flexion from erect posture, postural stability along the medio-lateral direction is organized in advance during "anticipatory postural adjustments" (APAs). This study aimed to investigate the influence of temporal pressure on this anticipatory postural control of medio-lateral stability. Eight young healthy participants performed series of leg flexions (1) as soon as possible in response to an acoustic signal (reaction-time condition; condition with temporal pressure) and (2) in a self-initiated condition (no temporal pressure). Results showed that APAs duration was shorter in the reaction-time condition as compared to the self-initiated condition; this shortening was compensated by an increase in the medio-lateral center-of-pressure displacement so that the dynamic stability reached at foot-off, as measured by the "extrapolated center-of-mass", remained unchanged. It is concluded that when a complex task is performed under temporal pressure, the central nervous system is able to modulate the spatio-temporal features of APAs in a way to both hasten the initiation of the voluntary movement and maintain optimal conditions of dynamic stability. In other words, it seems that the central nervous system does not "trade off optimal stability for speed of movement initiation under reaction-time condition", as it had been proposed in the literature.

  13. Influence of untreated chronic plastic iridocyclitis on intraocular pressure in leprosy patients.

    OpenAIRE

    Karaçorlu, M A; Cakiner, T; Saylan, T

    1991-01-01

    The intraocular pressures of a total of 286 eyes of patients with lepromatous and borderline lepromatous leprosy who never had regular ophthalmological care or local eye treatment were measured. The patients were categorised according to the type of leprosy they had, and the eyes were categorised as without or with chronic plastic iridocyclitis. In patients with lepromatous and borderline lepromatous types of leprosy the intraocular pressure was significantly lower in eyes with chronic plasti...

  14. Functional phenotype of airway myocytes from asthmatic airways

    NARCIS (Netherlands)

    Wright, David B.; Trian, Thomas; Siddiqui, Sana; Pascoe, Chris D.; Ojo, Oluwaseun O.; Johnson, Jill R.; Dekkers, Bart G. J.; Dakshinamurti, Shyamala; Bagchi, Rushita; Burgess, Janette K.; Kanabar, Varsha

    2013-01-01

    In asthma, the airway smooth muscle (ASM) cell plays a central role in disease pathogenesis through cellular changes which may impact on its microenvironment and alter ASM response and function. The answer to the long debated question of what makes a 'healthy' ASM cell become 'asthmatic' still remai

  15. Investigation of influence of coal properties on dense-phase pneumatic conveying at high pressure

    Institute of Scientific and Technical Information of China (English)

    Cai Liang; Xiaoxu Xie; Pan Xu; Xiaoping Chen; Changsui Zhao; Xin Wu

    2012-01-01

    Experiments of dense-phase pneumatic conveying of pulverized coal using nitrogen were carried out in a test facility at pressures of up to 3.7 MPa to study the effects of coal type,particle size and moisture content on flow characteristics.The Jenike shear test and scanning electron microscopy (SEM) were employed to provide a better understanding of effects of the material properties on flow characteristics.Two kinds of pulverized coals,Yanzhou and Datong,with similar particle size,moisture content and density,were used in the test.Pressure drop increases with increasing the particle size at similar solid-gas ratio,superficial velocity and pressure in the receiving hopper,and pressure drops through different test sections decrease firstly and then rise with increasing the conveying velocity for the same particle size,mass flow rate and pressure in the receiving hopper.The flowability of pulverized coal decreases with increasing the moisture content in the range from 3.24% to 8.18%.Unconfined yield strength (UYS) increases and flow function (FF) decreases with increasing the moisture content.Results of the shearing tests are consistent with the results of the conveying study.Pressure drops through different test sections are discussed and analyzed.

  16. Mode of Glucocorticoid Actions in Airway Disease

    Directory of Open Access Journals (Sweden)

    Kazuhiro Ito

    2006-01-01

    Full Text Available Synthetic glucocorticoids are the most potent anti-inflammatory agents used to treat chronic inflammatory disease, such as asthma. However, a small number (<5% of asthmatic patients and almost all patients with chronic obstructive pulmonary disease (COPD do not respond well, or at all, to glucocorticoid therapy. If the molecular mechanism of glucocorticoid insensitivity is uncovered, it may in turn provide insight into the key mechanism of glucocorticoid action and allow a rational way to implement treatment regimens that restore glucocorticoid sensitivity. Glucocorticoids exert their effects by binding to a cytoplasmic glucocorticoid receptor (GR, which is subjected to post-translational modifications. Receptor phosphorylation, acetylation, nitrosylation, ubiquitinylation, and other modifications influence hormone binding, nuclear translocation, and protein half-life. Analysis of GR interactions to other molecules, such as coactivators or corepressors, may explain the genetic specificity of GR action. Priming with inflammatory cytokine or oxidative/nitrative stress is a mechanism for the glucocorticoid resistance observed in chronic inflammatory airway disease via reduction of corepressors or GR modification. Therapies targeting these aspects of the GR activation pathway may reverse glucocorticoid resistance in patients with glucocorticoid-insensitive airway disease and some patients with other inflammatory diseases, such as rheumatoid arthritis and inflammatory bowel disease.

  17. Prolonged ozone exposure in an allergic airway disease model: Adaptation of airway responsiveness and airway remodeling

    Directory of Open Access Journals (Sweden)

    Park Chang-Soo

    2006-02-01

    Full Text Available Abstract Background Short-term exposure to high concentrations of ozone has been shown to increase airway hyper-responsiveness (AHR. Because the changes in AHR and airway inflammation and structure after chronic ozone exposure need to be determined, the goal of this study was to investigate these effects in a murine model of allergic airway disease. Methods We exposed BALB/c mice to 2 ppm ozone for 4, 8, and 12 weeks. We measured the enhanced pause (Penh to methacholine and performed cell differentials in bronchoalveolar lavage fluid. We quantified the levels of IL-4 and IFN-γ in the supernatants of the bronchoalveolar lavage fluids using enzyme immunoassays, and examined the airway architecture under light and electron microscopy. Results The groups exposed to ozone for 4, 8, and 12 weeks demonstrated decreased Penh at methacholine concentrations of 12.5, 25, and 50 mg/ml, with a dose-response curve to the right of that for the filtered-air group. Neutrophils and eosinophils increased in the group exposed to ozone for 4 weeks compared to those in the filtered-air group. The ratio of IL-4 to INF-γ increased significantly after exposure to ozone for 8 and 12 weeks compared to the ratio for the filtered-air group. The numbers of goblet cells, myofibroblasts, and smooth muscle cells showed time-dependent increases in lung tissue sections from the groups exposed to ozone for 4, 8, and 12 weeks. Conclusion These findings demonstrate that the increase in AHR associated with the allergic airway does not persist during chronic ozone exposure, indicating that airway remodeling and adaptation following repeated exposure to air pollutants can provide protection against AHR.

  18. The human airway epithelial basal cell transcriptome.

    Directory of Open Access Journals (Sweden)

    Neil R Hackett

    Full Text Available BACKGROUND: The human airway epithelium consists of 4 major cell types: ciliated, secretory, columnar and basal cells. During natural turnover and in response to injury, the airway basal cells function as stem/progenitor cells for the other airway cell types. The objective of this study is to better understand human airway epithelial basal cell biology by defining the gene expression signature of this cell population. METHODOLOGY/PRINCIPAL FINDINGS: Bronchial brushing was used to obtain airway epithelium from healthy nonsmokers. Microarrays were used to assess the transcriptome of basal cells purified from the airway epithelium in comparison to the transcriptome of the differentiated airway epithelium. This analysis identified the "human airway basal cell signature" as 1,161 unique genes with >5-fold higher expression level in basal cells compared to differentiated epithelium. The basal cell signature was suppressed when the basal cells differentiated into a ciliated airway epithelium in vitro. The basal cell signature displayed overlap with genes expressed in basal-like cells from other human tissues and with that of murine airway basal cells. Consistent with self-modulation as well as signaling to other airway cell types, the human airway basal cell signature was characterized by genes encoding extracellular matrix components, growth factors and growth factor receptors, including genes related to the EGF and VEGF pathways. Interestingly, while the basal cell signature overlaps that of basal-like cells of other organs, the human airway basal cell signature has features not previously associated with this cell type, including a unique pattern of genes encoding extracellular matrix components, G protein-coupled receptors, neuroactive ligands and receptors, and ion channels. CONCLUSION/SIGNIFICANCE: The human airway epithelial basal cell signature identified in the present study provides novel insights into the molecular phenotype and biology of

  19. Positive expiratory pressure and oscillatory positive expiratory pressure therapies.

    Science.gov (United States)

    Myers, Timothy R

    2007-10-01

    Airway clearance techniques, historically referred to as chest physical therapy, have traditionally consisted of a variety of breathing maneuvers or exercises and manual percussion and postural drainage. The methods and types of airway clearance techniques and devices have rapidly increased in an effort to find a more efficacious strategy that allows for self-therapy, better patient adherence and compliance, and more efficient durations of care. Mechanically applied pressure devices have migrated from European countries over the last several decades to clinical practice in the United States. I conducted a comprehensive MEDLINE search of two such devices: positive expiratory pressure (PEP) and oscillatory positive expiratory pressure (OPEP) and their role in airway clearance strategies. This was followed by a comprehensive search for cross-references in an attempt to identify additional studies. The results of that search are contained and reported in this review. From a methods standpoint, most of the studies of PEP and OPEP for airway clearance are limited by crossover designs and small sample sizes. While PEP and OPEP do not definitively prove superiority to other methods of airway clearance strategies, there is no clear evidence that they are inferior. Ultimately, the correct choice may be an airway clearance strategy that is clinically and cost effective, and is preferred by the patient so that adherence and compliance can be at the very least supported.

  20. Incidence of unanticipated difficult airway using an objective airway score versus a standard clinical airway assessment

    DEFF Research Database (Denmark)

    Nørskov, Anders Kehlet; Rosenstock, Charlotte Valentin; Wetterslev, Jørn

    2013-01-01

    the examination and registration of predictors for difficult mask ventilation with a non-specified clinical airway assessment on prediction of difficult mask ventilation.Method/Design: We cluster-randomized 28 Danish departments of anaesthesia to airway assessment either by the SARI or by usual non...... reduction equalling a number needed to treat of 180. Sample size estimation is adjusted for the study design and based on standards for randomization on cluster-level. With an average cluster size of 2,500 patients, 70,000 patients will be enrolled over a 1-year trial period. The database is programmed so...

  1. Estimation of influence of myofascial release techniques on esophageal pressure in patients after total laryngectomy.

    Science.gov (United States)

    Marszałek, Sławomir; Zebryk-Stopa, Anna; Kraśny, Jacek; Obrebowski, Andrzej; Golusiński, Wojciech

    2009-08-01

    In patients after total laryngectomy, increased tension in myofascial neck and arm areas might be observed. Via fascial continuity it has an adverse impact on the superior esophageal constrictor forming the "mouth of the oesophagus", which hinders learning of esophageal speech. The aim is to assess the effect of manual myofascial release techniques on esophageal pressure in patients after total laryngectomy. Forty patients (12 F, 28 M), aged 43-75 (mean 56.8 years), 9 months to 13 years (average 3 years) after total laryngectomy, 35 patients (87.5%) after neck lymph node resection, 38 patients (95%) after radiotherapy. Esophageal pressure was assessed using modified Seeman's method. Manual myofascial release techniques were applied within head, neck, arms, upper trunk and upper limb areas. Wilcoxon and Shapiro-Wilk's test was used for the purpose of statistical analysis. Statistically significant decrease of the mean esophageal pressure was observed after the physiotherapy treatment. The average pressure among the examined patients decreased from 37.9 to 26.6 mmHg. The application of myofascial manual techniques decreases esophageal pressure, thus allowing patients to learn esophagus speech at a faster pace.

  2. Vessel-guided Airway Tree Segmentation

    DEFF Research Database (Denmark)

    Lo, P.; Sporring, J.; Ashraf, H.;

    2010-01-01

    This paper presents a method for airway tree segmentation that uses a combination of a trained airway appearance model, vessel and airway orientation information, and region growing. We propose a voxel classification approach for the appearance model, which uses a classifier that is trained...... method is evaluated on 250 low dose computed tomography images from a lung cancer screening trial. Our experiments showed that applying the region growing algorithm on the airway appearance model produces more complete airway segmentations, leading to on average 20% longer trees, and 50% less leakage...

  3. Inflammatory bowel disease and airway diseases

    Science.gov (United States)

    Vutcovici, Maria; Brassard, Paul; Bitton, Alain

    2016-01-01

    Airway diseases are the most commonly described lung manifestations of inflammatory bowel disease (IBD). However, the similarities in disease pathogenesis and the sharing of important environmental risk factors and genetic susceptibility suggest that there is a complex interplay between IBD and airway diseases. Recent evidence of IBD occurrence among patients with airway diseases and the higher than estimated prevalence of subclinical airway injuries among IBD patients support the hypothes