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Sample records for airway pressure influences

  1. Influence of bilevel positive airway pressure on autonomic tone in hospitalized patients with decompensated heart failure.

    Science.gov (United States)

    Lacerda, Diego; Costa, Dirceu; Reis, Michel; Gomes, Evelim Leal de F Dantas; Costa, Ivan Peres; Borghi-Silva, Audrey; Marsico, Aline; Stirbulov, Roberto; Arena, Ross; Sampaio, Luciana Maria Malosá

    2016-01-01

    [Purpose] This study evaluated the effect of Bilevel Positive Airway (BiPAP) on the autonomic control of heart rate, assessed by heart rate variability (HRV), in patients hospitalized with decompensated heart failure. [Subjects and Methods] This prospective cross-sectional study included 20 subjects (age: 69±8 years, 12 male, left ventricular ejection fraction: 36 ±8%) diagnosed with heart failure who were admitted to a semi-intensive care unit with acute decompensation. Date was collected for HRV analysis during: 10 minutes spontaneous breathing in the resting supine position; 30 minutes breathing with BiPAP application (inspiratory pressure = 20 cmH2O and expiratory pressure = 10 cmH2O); and 10 minutes immediately after removal of BiPAP, during the return to spontaneous breathing. [Results] Significantly higher values for indices representative of increased parasympathetic activity were found in the time and frequency domains as well as in nonlinear Poincaré analysis during and after BiPAP in comparison to baseline. Linear HRV analysis: standard deviation of the average of all R-R intervals in milliseconds = 30.99±4.4 pre, 40.3±6.2 during, and 53.3±12.5 post BiPAP. Non-linear HRV analysis: standard deviations parallel in milliseconds = 8.31±4.3 pre, 12.9±5.8 during, and 22.8 ±6.3 post BiPAP. [Conclusion] The present findings demonstrate that BiPAP enhances vagal tone in patients with heart failure, which is beneficial for patients suffering from acute decompensation. PMID:26957719

  2. Nasal continuous positive airway pressure

    DEFF Research Database (Denmark)

    Scholze, Alexandra; Lamwers, Stephanie; Tepel, Martin; Sanner, Bernd M

    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 volume...... automated analysis. In patients with OSA and an apnoea/hypopnoea index (AHI) of >10 events · h(-1), a significant vasoconstriction was observed during the night (p<0.0001 by Friedman's test). A significant positive correlation existed between vasoconstriction and AHI (Spearman correlation, r = 0.27; p<0.......01; n = 94) and the arousal index (Spearman correlation, r = 0.21; p < 0.05; n = 94). After 6 months of nCPAP treatment, the AHI was significantly reduced from 27 ± 3 events · h(-1) to 4 ± 2 events · h(-1) (each n = 29; p<0.001) and vasoconstriction during the night was significantly reduced from 10 ± 3...

  3. Influence of bilevel positive airway pressure on autonomic tone in hospitalized patients with decompensated heart failure

    OpenAIRE

    Lacerda, Diego; Costa, Dirceu; Reis, Michel; Gomes, Evelim Leal de F. Dantas; Costa, Ivan Peres; Borghi-Silva, Audrey; Marsico, Aline; Stirbulov, Roberto; Arena, Ross; Sampaio, Luciana Maria Malosá

    2016-01-01

    [Purpose] This study evaluated the effect of Bilevel Positive Airway (BiPAP) on the autonomic control of heart rate, assessed by heart rate variability (HRV), in patients hospitalized with decompensated heart failure. [Subjects and Methods] This prospective cross-sectional study included 20 subjects (age: 69±8 years, 12 male, left ventricular ejection fraction: 36 ±8%) diagnosed with heart failure who were admitted to a semi-intensive care unit with acute decompensation. Date was collected fo...

  4. Nasal airway responses to nasal continuous positive airway pressure breathing: An in-vivo pilot study.

    Science.gov (United States)

    White, David E; Bartley, Jim; Shakeel, Muhammad; Nates, Roy J; Hankin, Robin K S

    2016-06-14

    The nasal cycle, through variation in nasal airflow partitioning, allows the upper airway to accommodate the contrasting demands of air conditioning and removal of entrapped air contaminants. The purpose of this study was to investigate the influence of nasal continuous positive airway pressure (nCPAP) breathing has on both nasal airflow partitioning and nasal geometry. Using a custom-made nasal mask, twenty healthy participants had the airflow in each naris measured during normal nasal breathing followed by nCPAP breathing. Eight participants also underwent magnetic resonance imaging (MRI) of the nasal region during spontaneous nasal breathing, and then nCPAP breathing over a range of air pressures. During nCPAP breathing, a simultaneous reduction in airflow through the patent airway together with a corresponding increase in airway flow within the congested nasal airway were observed in sixteen of the twenty participants. Nasal airflow resistance is inversely proportional to airway cross-sectional area. MRI data analysis during nCPAP breathing confirmed airway cross-sectional area reduced along the patent airway while the congested airway experienced an increase in this parameter. During awake breathing, nCPAP disturbs the normal inter-nasal airflow partitioning. This could partially explain the adverse nasal drying symptoms frequently reported by many users of this therapy. PMID:27173595

  5. 21 CFR 868.2600 - Airway pressure monitor.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2600 Airway pressure monitor. (a) Identification. An airway pressure monitor is a device used to measure the pressure in a patient's upper airway... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Airway pressure monitor. 868.2600 Section...

  6. 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; Pott, F C

    2007-01-01

    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...... 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 <0.......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...

  7. 食管引流型喉罩间歇正压通气时头前屈位对气道密封压的影响%Influence of head anteflexion on airway sealing pressure during intermittent positive pressure ventilation with ProSeal laryngeal mask airway with an esophageal vent

    Institute of Scientific and Technical Information of China (English)

    李成文; 薛富善; 刘鲲鹏

    2010-01-01

    Objective To evaluate the influence of head anteflexion on airway sealing pressure during intermittent positive pressure ventilation(IPPV) with ProSeal laryngeal mask airway (PLMA) with an esophageal vent.Methods Fifty ASA Ⅰ or Ⅱ patients (20 males and 30 females), aged 18-51 ye are, weighing 50-70 kg and scheduled for elective plastic surgery under general anesthesia, were enrolled in this study. Anesthesia was induced with fentanyl 2 μg/kg, propofol 2 μg/kg and vecuromium 0.1 mg/kg. PLMA with an esophageal vent was inserted at 2 min after intravenous vecuronium injection.The airway sealing pressure, the anatomic position of the cuff and the efficacy of positive pressure ventilation were checked in the neutral and anteflexed head positions with the cuff deflated and inflated to an intracuff pressure of 60 cm H2 O, respectively.Results The lungs were better ventilated in the head anteflexion position than in the head neutral position whether the cuff was deflated or inflated. There was no significant difference in the volume of air required to achieve an intracuff pressure of 60 cm H2O between the two head positions ( P> 0.05). The airway seating pressure increased from (27 ± 6) cm H2O in the head neutral position to (33 ± 6) cm H2O in the head anteflexion position, with no significant difference between them ( P> 0.05). The expired tidal volume and the peak inspiratory pressure during IPPV were (496 ± 81 ) ml and (14.3 ± 1.9) cm H2O respectively in the head neutral position and (496 ± 81 ) ml and ( 14.5 ± 2.1 )cm H2O respectively in the head anteflexion position.Conclusion Head anteflexion can significantly improve airway sealing but does not affect the anatomic position of the cuff.Appropriate head anteflexion is a simple and effective way to improve IPPV when the airway sealing pressure is inadequate in the head neutral position.

  8. Predictors of continuous positive airway pressure adherence

    OpenAIRE

    Catcheside, Peter G.

    2010-01-01

    Continuous positive airway pressure (CPAP) is the leading treatment for obstructive sleep apnoea (OSA), a prevalent disorder of breathing in sleep strongly associated with obesity. OSA has serious adverse health, social and community effects arising from disturbed breathing, loud snoring, poor quality sleep and cardiovascular sequelae. When used appropriately, CPAP treatment is highly effective in normalising breathing and sleep, improving symptoms and lowering adverse event risk. However, pa...

  9. 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.

  10. 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.

  11. Elephantoid eyelid edema associated with continuous positive airway pressure treatment.

    Science.gov (United States)

    Chiam, Patrick J T; Hubbard, Alan D

    2013-01-01

    A man with rosacea developed bilateral eyelid edema from wearing a continuous positive airway pressure nasal mask daily. The edema was refractory to steroid, diuretics, and lymphatic drainage massage. The effect may be related to cumulative venous congestion and lymphostasis due to the continuous positive airway pressure treatment. PMID:23128530

  12. Continuous positive airway pressure titration in infants with severe upper airway obstruction or bronchopulmonary dysplasia.

    OpenAIRE

    Khirani, Sonia; Ramirez, Adriana; Aloui, Sabrina; Leboulanger, Nicolas; Picard, Arnaud; Fauroux, Brigitte

    2013-01-01

    Abstracta Introduction Noninvasive continuous positive airway pressure (CPAP) is recognized as an effective treatment for severe airway obstruction in young children. The aim of the present study was to compare a clinical setting with a physiological setting of noninvasive CPAP in infants with nocturnal alveolar hypoventilation due to severe upper airway obstruction (UAO) or bronchopulmonary dysplasia (BPD). Methods The breathing pattern and respiratory muscle output of all consecutive infant...

  13. Biphasic positive airway pressure ventilation (PeV+) in children

    OpenAIRE

    Jaarsma, Anneke S; Knoester, Hennie; van Rooyen, Frank; Bos, Albert P.

    2001-01-01

    Background: Biphasic positive airway pressure (BIPAP) (also known as PeV+) is a mode of ventilation with cycling variations between two continuous positive airway pressure levels. In adults this mode of ventilation is effective and is being accepted with a decrease in need for sedatives because of the ability to breathe spontaneously during the entire breathing cycle. We studied the use of BIPAP in infants and children. Methods: We randomized 18 patients with respiratory failure for ventilati...

  14. Chronic continuous positive airway pressure (CPAP) reduces airway reactivity in vivo in an allergen-induced rabbit model of asthma

    OpenAIRE

    Xue, Z.; Yu, Y.; Gao, H.; Gunst, S.J.; Tepper, R.S.

    2011-01-01

    Previous studies have demonstrated that chronic mechanical strain produced by continuous positive airway pressure (CPAP) reduces in vivo airway reactivity in rabbits and ferrets. For CPAP to potentially have a therapeutic benefit for asthmatic subjects, the reduction in airway responsiveness would need to persist for 12–24 h after its discontinuation, require application for only part of the day, and be effective in the presence of atopic airway inflammation. In the present study, airway resp...

  15. Increased airway reactivity in a neonatal mouse model of Continuous Positive Airway Pressure (CPAP)

    OpenAIRE

    Mayer, Catherine A; Martin, Richard J.; MacFarlane, Peter M.

    2015-01-01

    Background Continuous positive airway pressure (CPAP) is a primary form of respiratory support used in the intensive care of preterm infants, but its long-term effects on airway (AW) function are unknown. Methods We developed a neonatal mouse model of CPAP treatment to determine whether it modifies later AW reactivity. Un-anesthetized spontaneously breathing mice were fitted with a mask to deliver CPAP (6cmH2O, 3hrs/day) for 7 consecutive days starting at postnatal day 1. Airway reactivity to...

  16. 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

  17. Automatic nasal continuous positive airway pressure titration in the laboratory: patient outcomes

    OpenAIRE

    Stradling, J. R.; Barbour, C.; Pitson, D. J.; Davies, R J

    1997-01-01

    BACKGROUND: Manual titration of nasal continuous positive airway pressure (NCPAP) treatment for obstructive sleep apnoea (OSA) is time consuming and expensive. There are now "intelligent" NCPAP machines that try to find the ideal pressure for a patient by monitoring a combination of apnoeas, hypopnoeas, inspiratory flow limitation, and snoring. Although these machines usually find similar pressures to skilled technicians, it is not clear if their use in the sleep laboratory influences s...

  18. Boussignac continuous positive airway pressure for weaning with tracheostomy tubes

    NARCIS (Netherlands)

    Dieperink, Willem; Aarts, Leon P. H. J.; Rodgers, Michael G. G.; Delwig, Hans; Nijsten, Maarten W. N.

    2008-01-01

    Background: In patients who are weaned with a tracheostomy tube ( TT), continuous positive airway pressure ( CPAP) is frequently used. Dedicated CPAP systems or ventilators with bulky tubing are usually applied. However, CPAP can also be effective without a ventilator by the disposable Bous-signac C

  19. Prolonged positive airway pressure for severe neonatal tracheobronchomalacia.

    OpenAIRE

    Pizer, B.L.; Freeland, A P; A R Wilkinson

    1986-01-01

    A very low birthweight preterm baby with respiratory distress at birth was found to have severe congenital tracheobronchomalacia. Continuous positive airway pressure was given through an endotracheal tube without tracheostomy for 15 weeks before unassisted respiration could be maintained. Diagnosis was made and progress monitored by laryngobronchoscopy on three occasions.

  20. Periorbital Edema Secondary to Positive Airway Pressure Therapy

    OpenAIRE

    Dandekar, F.; Camacho, M; J. Valerio; Ruoff, C.

    2015-01-01

    Two patients developed bilateral, periorbital edema after initiating positive airway pressure (PAP) therapy with a full face mask. The periorbital edema was more pronounced in the morning and would dissipate throughout the day. This phenomenon seemed to be correlated with the direct pressure of the full face mask, which may have impaired lymphatic and venous drainage. To test this hypothesis, each patient was changed to a nasal pillow interface with subsequent improvement in the periorbital e...

  1. 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

  2. Portable power supply options for positive airway pressure devices.

    OpenAIRE

    Riaz, M.; Certal, V; M. Camacho

    2015-01-01

    INTRODUCTION: Patients with obstructive sleep apnea (OSA) often face the challenge of how to power their positive airway pressure (PAP) devices when alternating current power supplies are not available in remote areas with lack of electricity or frequent power outages. This article elucidates portable power supply options for PAP devices with the aim to increase alternative power source awareness among medical providers. METHODS: A search of scientific databases (Medline, Scopus, Web...

  3. Compliance with Positive Airway Pressure Treatment for Obstructive Sleep Apnea

    OpenAIRE

    Kim, Ji Heui; Kwon, Min Su; Song, Hyung Min; Lee, Bong-Jae; Jang, Yong Ju; Chung, Yoo-Sam

    2009-01-01

    Objectives Positive airway pressure (PAP) is considered a standard treatment for moderate-to-severe obstructive sleep apnea (OSA) patients. However, compliance with PAP treatment is suboptimal because of several types of discomfort experienced by patients. This study investigated compliance with PAP therapy, and affecting factors for such compliance, in OSA patients. Methods We performed a survey on 69 patients who engaged in PAP therapy between December 2006 and November 2007. After diagnost...

  4. Type of Mask May Impact on Continuous Positive Airway Pressure Adherence in Apneic Patients

    OpenAIRE

    Borel, Jean Christian; Tamisier, Renaud; Dias-Domingos, Sonia; Sapene, Marc; Martin, Francis; Stach, Bruno; Grillet, Yves; Muir, Jean François; Levy, Patrick; Series, Frederic; Pepin, Jean-Louis; ,

    2013-01-01

    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 natio...

  5. Control system design for a Continuous Positive Airway Pressure ventilator.

    Science.gov (United States)

    Chen, Zheng-Long; Hu, Zhao-Yan; Dai, Hou-De

    2012-01-01

    Continuous Positive Airway Pressure (CPAP) ventilation remains a mainstay treatment for obstructive sleep apnea syndrome (OSAS). Good pressure stability and pressure reduction during exhalation are of major importance to ensure clinical efficacy and comfort of CPAP therapy. In this study an experimental CPAP ventilator was constructed using an application-specific CPAP blower/motor assembly and a microprocessor. To minimize pressure variations caused by spontaneous breathing as well as the uncomfortable feeling of exhaling against positive pressure, we developed a composite control approach including the feed forward compensator and feedback proportional-integral-derivative (PID) compensator to regulate the pressure delivered to OSAS patients. The Ziegler and Nichols method was used to tune PID controller parameters. And then we used a gas flow analyzer (VT PLUS HF) to test pressure curves, flow curves and pressure-volume loops for the proposed CPAP ventilator. The results showed that it met technical criteria for sleep apnea breathing therapy equipment. Finally, the study made a quantitative comparison of pressure stability between the experimental CPAP ventilator and commercially available CPAP devices. PMID:22296604

  6. Control system design for a continuous positive airway pressure ventilator

    Directory of Open Access Journals (Sweden)

    Chen Zheng-Long

    2012-02-01

    Full Text Available Abstract Continuous Positive Airway Pressure (CPAP ventilation remains a mainstay treatment for obstructive sleep apnea syndrome (OSAS. Good pressure stability and pressure reduction during exhalation are of major importance to ensure clinical efficacy and comfort of CPAP therapy. In this study an experimental CPAP ventilator was constructed using an application-specific CPAP blower/motor assembly and a microprocessor. To minimize pressure variations caused by spontaneous breathing as well as the uncomfortable feeling of exhaling against positive pressure, we developed a composite control approach including the feed forward compensator and feedback proportional-integral-derivative (PID compensator to regulate the pressure delivered to OSAS patients. The Ziegler and Nichols method was used to tune PID controller parameters. And then we used a gas flow analyzer (VT PLUS HF to test pressure curves, flow curves and pressure-volume loops for the proposed CPAP ventilator. The results showed that it met technical criteria for sleep apnea breathing therapy equipment. Finally, the study made a quantitative comparison of pressure stability between the experimental CPAP ventilator and commercially available CPAP devices.

  7. Non-invasive ventilation in acute respiratory failure: a randomised comparison of continuous positive airway pressure and bi-level positive airway pressure

    OpenAIRE

    Cross, A.; Cameron, P.; Kierce, M; Ragg, M; Kelly, A.

    2003-01-01

    Objectives: To determine whether there is a difference in required duration of non-invasive ventilation between continuous positive airway pressure (CPAP) and bi-level positive airway pressure (BiPAP) in the treatment of a heterogeneous group of emergency department (ED) patients suffering acute respiratory failure and the subgroup of patients with acute pulmonary oedema (APO). Secondary objectives were to compare complications, failure rate, disposition, length of stay parameters, and mortal...

  8. 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....

  9. 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.

  10. Hemodynamic effects of nasal continuous positive airway pressure in preterm infants with evolving chronic lung disease, a crossover randomized trial.

    Science.gov (United States)

    Beker, Friederike; Rogerson, Sheryle R; Hooper, Stuart B; Sehgal, Arvind; Davis, Peter G

    2015-02-01

    Previous studies suggest that high airway pressure may compromise cardiac output. We investigated the effect of 3 nasal continuous positive airway pressure levels on cardiac output in preterm infants with evolving chronic lung disease. We found that brief changes in continuous positive airway pressure did not affect cardiac output. PMID:25454930

  11. Regional lung aeration and ventilation during pressure support and biphasic positive airway pressure ventilation in experimental lung injury

    OpenAIRE

    Gama de Abreu, Marcelo; Cuevas, Maximiliano; Spieth, Peter M; Carvalho, Alysson R; Hietschold, Volker; Stroszczynski, Christian; Wiedemann, Bärbel; Koch, Thea; Pelosi, Paolo; Koch, Edmund

    2010-01-01

    Introduction There is an increasing interest in biphasic positive airway pressure with spontaneous breathing (BIPAP+SBmean), which is a combination of time-cycled controlled breaths at two levels of continuous positive airway pressure (BIPAP+SBcontrolled) and non-assisted spontaneous breathing (BIPAP+SBspont), in the early phase of acute lung injury (ALI). However, pressure support ventilation (PSV) remains the most commonly used mode of assisted ventilation. To date, the effects of BIPAP+SBm...

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

    OpenAIRE

    Marcelo Park; Geraldo Lorenzi-Filho; Maria Inês Feltrim; Paulo Ricardo Nazário Viecili; Márcia Cristina Sangean; Márcia Volpe; Paulo Ferreira Leite; Alfredo José Mansur

    2001-01-01

    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 noninvas...

  13. Tonic activity in inspiratory muscles during continuous negative airway pressure.

    Science.gov (United States)

    Meessen, N E; van der Grinten, C P; Folgering, H T; Luijendijk, S C

    1993-05-01

    We studied tonic inspiratory activity (TIA) induced by continuous negative airway pressure (CNAP) in anaesthetized, spontaneously breathing cats. TIA in the diaphragm and parasternal intercostal muscles (ICM) was quantified in response to tracheal pressure (PTR) = -0.3 to -1.2 kPa. To differentiate between reflexes from rapidly adapting receptors (RARs), slowly adapting receptors (SARs) and C-fiber endings different temperatures of the vagus nerves (TVG) were used between 4 and 37 degrees C. At PTR = -1.2 kPa mean TIA values were 41% and 62% of peak inspiratory EMG activity of control breaths for the diaphragm and ICM, respectively. After vagotomy and for TVG < 6 degrees C CNAP did not induce TIA anymore. Changes in inspiratory and expiratory time during vagal cooling down to 4 degrees C confirmed the selective block of conductance in vagal afferents of the three types of lung receptors. We conclude that CNAP-induced TIA results from stimulation of RARs. Our data strongly indicate that stimulation of SARs suppresses TIA, whereas C-fiber endings are not involved in TIA at all. The results suggest that part of the hyperinflation in bronchial asthma may be caused by TIA in response to mechanical stimulation of RARs. PMID:8327788

  14. The 30-year evolution of airway pressure release ventilation (APRV).

    Science.gov (United States)

    Jain, Sumeet V; Kollisch-Singule, Michaela; Sadowitz, Benjamin; Dombert, Luke; Satalin, Josh; Andrews, Penny; Gatto, Louis A; Nieman, Gary F; Habashi, Nader M

    2016-12-01

    Airway pressure release ventilation (APRV) was first described in 1987 and defined as continuous positive airway pressure (CPAP) with a brief release while allowing the patient to spontaneously breathe throughout the respiratory cycle. The current understanding of the optimal strategy to minimize ventilator-induced lung injury is to "open the lung and keep it open". APRV should be ideal for this strategy with the prolonged CPAP duration recruiting the lung and the minimal release duration preventing lung collapse. However, APRV is inconsistently defined with significant variation in the settings used in experimental studies and in clinical practice. The goal of this review was to analyze the published literature and determine APRV efficacy as a lung-protective strategy. We reviewed all original articles in which the authors stated that APRV was used. The primary analysis was to correlate APRV settings with physiologic and clinical outcomes. Results showed that there was tremendous variation in settings that were all defined as APRV, particularly CPAP and release phase duration and the parameters used to guide these settings. Thus, it was impossible to assess efficacy of a single strategy since almost none of the APRV settings were identical. Therefore, we divided all APRV studies divided into two basic categories: (1) fixed-setting APRV (F-APRV) in which the release phase is set and left constant; and (2) personalized-APRV (P-APRV) in which the release phase is set based on changes in lung mechanics using the slope of the expiratory flow curve. Results showed that in no study was there a statistically significant worse outcome with APRV, regardless of the settings (F-ARPV or P-APRV). Multiple studies demonstrated that P-APRV stabilizes alveoli and reduces the incidence of acute respiratory distress syndrome (ARDS) in clinically relevant animal models and in trauma patients. In conclusion, over the 30 years since the mode's inception there have been no strict

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

    OpenAIRE

    Stasche, Norbert

    2006-01-01

    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 PA...

  18. 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.

  19. The effects of posture, airway pressure and anesthesia on regulation of the regional ventilation and perfusion distribution in healthy humans

    OpenAIRE

    Nyrén, Sven

    2010-01-01

    Gas exchange has been observed to vary with posture in adult respiratory distress syndrome (ARDS) patients. In this thesis, the effect of posture on theregional distribution of ventilation (V) and perfusion (Q) in the lungs under normal breathing with and without continuous positive airway pressure (CPAP) and during general anesthesia with mechanical ventilation was studied. Additionally, endogenously produced nitric oxide (NO) may influence the effect of posture on the Q di...

  20. 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.

  1. Genes That Influence Blood Pressure

    Science.gov (United States)

    ... Research Matters NIH Research Matters September 26, 2011 Genes that Influence Blood Pressure In one of the ... 16 previously unknown variations. Six were found in genes already suspected of regulating blood pressure. The remaining ...

  2. The effects of heated humidifier in continuous positive airway pressure titration

    OpenAIRE

    Yu, Chung-Chieh; Luo, Cheng-Ming; Liu, Yu-Chih; Wu, Huang-Pin

    2012-01-01

    Background Previous studies have shown that routine heated humidifier (HH) do not provide any benefit during continuous positive airway pressure (CPAP) titration if there are no significant naso-pharyngeal symptoms. In clinical practice, nasal diseases and upper airway symptoms are very common. This study investigates the effects of HH during CPAP titration in subjects with or without naso-pharyngeal symptoms. Methods Fifty-two patients who received polysomnography with CPAP titration were ra...

  3. [Numerical simulation of the internal noise in the pressure generator of a continuous positive airway pressure ventilator].

    Science.gov (United States)

    Cheng, Yunzhang; Huang, Fangfang; Zhu, Lihua

    2013-04-01

    It is important to overcome the problem of noise for the research and development of ventilator technologies. Previous research of this subject showed that the pressure generator, produced by German EMB-PAPST Company and specially used for continuous positive airway pressure (CPAP) ventilator, created noise easily, due to local backflow in the volute, uneven velocity distribution in the impeller and local negative pressure in the inlet of the impeller. Based on the previous research, a combination of the computational fluid dynamics (CFD) software FLUENT and steady-state solution of noise source of Reynolds-Averaged Navier-Stokes (RANS) was used in this study. We combined equation of Lilley and Synthetic Turbulence to get the information about speed fluctuation of the pressure generator, which is used to finish noise prediction. After detailed analysis, it showed that noise source of different degrees spreaded around the inlet of the impeller and the volute, interface of blade edge and corner of the volute tongue, which influenced its overall performance to certain extent. Therefore, its structural design needs to be improved. PMID:23858754

  4. Simulated flying altitude and performance of continuous positive airway pressure devices

    OpenAIRE

    Sehlin, Maria; Brändström, Helge; Winsö, Ola; Haney, Michael; Wadell, Karin; Öhberg, Fredrik

    2014-01-01

    INTRODUCTION: Continuous positive airway pressure (CPAP) is used in air ambulances to treat patients with impaired oxygenation. Differences in mechanical principles between CPAP devices may affect their performance at different ambient air pressures as will occur in an air ambulance during flight. METHODS: Two different CPAP systems, a threshold resistor device and a flow resistor device, at settings 5 and 10 cm H2O were examined. Static pressure, static airflow and pressure during simulated ...

  5. Pressure-controlled inverse ratio ventilation using laryngeal mask airway in gynecological laparoscopy

    Directory of Open Access Journals (Sweden)

    Manju Sinha

    2012-01-01

    Full Text Available Background: It is well documented that pressure-controlled ventilation (PCV improves oxygenation and ventilation compared to volume-controlled ventilation and reduces peak airway pressure in gynecological laparoscopy. PCV with moderately inversed inspiratory-expiratory (I: E ratio can successfully recruit collapsed alveoli and has been proved to be beneficial in intensive care. We tested the hypothesis that altering the I: E ratio to 1.5:1 in PCV improves ventilation during gynecological laparoscopy using laryngeal mask airway (LMA. Objective: To study pressure-controlled inverse ratio ventilation (PCIRV with I: E ratio 1.5:1 as against PCV with I: E ratio 1:2 in gynecological laparoscopy with LMA using noninvasive parameters. Materials and Methods: Intraoperative hemodynamics and side-stream spirometry recordings were noted in 20 consecutive patients undergoing major gynecological laparoscopy with LMA. Flexible LMA or LMA supreme were used depending on normal body mass index (BMI or high BMI, respectively. Results: Reversing the I: E ratio to 1.5:1 increased the tidal volume, mean airway pressures, and dynamic lung compliance significantly, all indicating better oxygenation at comparable peak airway pressures as against PCV with I: E ratio 1:2. There was no change in the end-tidal carbon dioxide. There was no auto-positive end expiratory pressure (PEEP or change in the hemodynamics. Conclusion: Reversal of I: E ratio with PCV can be beneficially used with LMA in laparoscopy.

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

    Science.gov (United States)

    Tichanon, Promsrisuk; Sopida, Santamit; Orapin, Pasurivong; Watchara, Boonsawat; Banjamas, Intarapoka

    2016-01-01

    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. PMID:27445526

  7. Noninvasive Positive Pressure Ventilation or Conventional Mechanical Ventilation for Neonatal Continuous Positive Airway Pressure Failure

    Directory of Open Access Journals (Sweden)

    Zohreh Badiee

    2014-01-01

    Full Text Available Background: The aim of this study was to assess the success rate of nasal intermittent positive pressure ventilation (NIPPV for treatment of continuous positive airway pressure (CPAP failure and prevention of conventional ventilation (CV in preterm neonates. Methods: Since November 2012 to April 2013, a total number of 55 consecutive newborns with gestational ages of 26-35 weeks who had CPAP failure were randomly assigned to one of the two groups. The NIPPV group received NIPPV with the initial peak inspiratory pressure (PIP of 16-20 cmH 2 O and frequency of 40-60 breaths/min. The CV group received PIP of 12-20 cmH 2 O and frequency of 40-60 breaths/min. Results: About 74% of newborns who received NIPPV for management of CPAP failure responded to NIPPV and did not need intubation and mechanical ventilation. Newborns with lower postnatal age at entry to the study and lower 5 min Apgar score more likely had NIPPV failure. In addition, treatment failure was higher in newborns who needed more frequent doses of surfactant. Duration of oxygen therapy was 9.28 days in CV group and 7.77 days in NIPPV group (P = 0.050. Length of hospital stay in CV group and NIPPV groups were 48.7 and 41.7 days, respectively (P = 0.097. Conclusions: NIPPV could decrease the need for intubation and mechanical ventilation in preterm infants with CPAP failure.

  8. 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…

  9. 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

  10. Effects of pulmonary vascular pressures and flow on airway and parenchymal mechanics in isolated rat lungs

    OpenAIRE

    Petak, Ferenc; Habre, Walid; Hantos, Zoltán; Peter D Sly; Morel, Denis

    2002-01-01

    Changes in pulmonary hemodynamics have been shown to alter the mechanical properties of the lungs, but the exact mechanisms are not clear. We therefore investigated the effects of alterations in pulmonary vascular pressure and flow (Q(p)) on the mechanical properties of the airways and the parenchyma by varying these parameters independently in three groups of isolated perfused normal rat lungs. The pulmonary capillary pressure (Pc(est)), estimated from the pulmonary arterial (Ppa) and left a...

  11. Treatment of sleep-disordered breathing with positive airway pressure devices: technology update

    OpenAIRE

    Johnson KG; Johnson DC

    2015-01-01

    Karin Gardner Johnson, Douglas Clark Johnson Department of Medicine, Baystate Medical Center, Springfield, MA, USA Abstract: Many types of positive airway pressure (PAP) devices are used to treat sleep-disordered breathing including obstructive sleep apnea, central sleep apnea, and sleep-related hypoventilation. These include continuous PAP, autoadjusting CPAP, bilevel PAP, adaptive servoventilation, and volume-assured pressure support. Noninvasive PAP has significant leak by design, which t...

  12. Influence of airway wall compliance on epithelial cell injury and adhesion during interfacial flows

    Science.gov (United States)

    Higuita-Castro, Natalia; Mihai, Cosmin; Hansford, Derek J.

    2014-01-01

    Interfacial flows during cyclic airway reopening are an important source of ventilator-induced lung injury. However, it is not known how changes in airway wall compliance influence cell injury during airway reopening. We used an in vitro model of airway reopening in a compliant microchannel to investigate how airway wall stiffness influences epithelial cell injury. Epithelial cells were grown on gel substrates with different rigidities, and cellular responses to substrate stiffness were evaluated in terms of metabolic activity, mechanics, morphology, and adhesion. Repeated microbubble propagations were used to simulate cyclic airway reopening, and cell injury and detachment were quantified via live/dead staining. Although cells cultured on softer gels exhibited a reduced elastic modulus, these cells experienced less plasma membrane rupture/necrosis. Cells on rigid gels exhibited a minor, but statistically significant, increase in the power law exponent and also exhibited a significantly larger height-to-length aspect ratio. Previous studies indicate that this change in morphology amplifies interfacial stresses and, therefore, correlates with the increased necrosis observed during airway reopening. Although cells cultured on stiff substrates exhibited more plasma membrane rupture, these cells experienced significantly less detachment and monolayer disruption during airway reopening. Western blotting and immunofluorescence indicate that this protection from detachment and monolayer disruption correlates with increased focal adhesion kinase and phosphorylated paxillin expression. Therefore, changes in cell morphology and focal adhesion structure may govern injury responses during compliant airway reopening. In addition, these results indicate that changes in airway compliance, as occurs during fibrosis or emphysema, may significantly influence cell injury during mechanical ventilation. PMID:25213636

  13. Upper airway pressure-flow relationships and pharyngeal constrictor EMG activity during prolonged expiration in awake goats

    OpenAIRE

    O'Halloran, K. D.; Bisgard, G. E.

    2008-01-01

    We undertook the present investigation to establish whether narrowing/closure of the upper airway occurs during spontaneous and provoked respiratory rhythm disturbances and whether pharyngeal constrictor muscle recruitment occurs coincident with upper airway occlusion during prolonged expiratory periods. Upper airway pressure-flow relationships and middle pharyngeal constrictor (mPC) EMG activities were recorded in 11 adult female goats during spontaneous and provoked prolongations in expirat...

  14. Treatment of obstructive sleep-disordered breathing with positive airway pressure systems

    Directory of Open Access Journals (Sweden)

    D. Pevernagie

    2007-12-01

    Full Text Available Positive airway pressure systems are widely used to treat patients with moderate-to-severe obstructive sleep-disordered breathing. The application of stable continuous positive airway pressure (CPAP via the nose (nasal CPAP has been the mainstay of treatment since the early 1980s. For treatment to be effective, the pressure level must be fine-tuned to restore patency of the individual patient's upper airway. Currently, there is ongoing controversy concerning which outcomes to observe when adapting the pressure level, and which methods to use for pressure adaptation. Adjusting the pressure level to control apnoeas and hypopnoeas is one major objective, but may not be sufficient to restore normal sleep. Evidence is available that elimination of inspiratory flow limitation leads to better results. In recent years, it has become evident that the use of empirically set CPAP or automatic CPAP devices parallel the clinical results obtained with the classical approach of manual CPAP titration. A striking and still unexplained paradox lies in the fact that automatic CPAP devices perform very differently on the bench, but still yield satisfactory results on several clinical outcomes, e.g. control of sleep-related respiratory disturbances, restoration of good sleep quality and daytime alertness. Understanding the functioning of automatic CPAP devices can prove difficult, as the mode of operation is usually not disclosed by the manufacturers. At present, it is impossible to make any scientifically sound statement on the appropriateness of using automatic continuous positive airway pressure devices for the routine treatment of patients with obstructive sleep-disordered breathing. For this purpose, convincing results of phase I–III clinical trials are needed.

  15. 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.

  16. Biphasic positive airway pressure minimizes biological impact on lung tissue in mild acute lung injury independent of etiology

    OpenAIRE

    Saddy, Felipe; Moraes, Lillian; Santos, Cintia Lourenço; Oliveira, Gisele Pena; Cruz, Fernanda Ferreira; Morales, Marcelo Marcos; Capelozzi, Vera Luiza; de Abreu, Marcelo Gama; Baez Garcia, Cristiane Souza Nascimento; Pelosi, Paolo; Rocco, Patricia Rieken Macêdo

    2013-01-01

    Introduction Biphasic positive airway pressure (BIVENT) is a partial support mode that employs pressure-controlled, time-cycled ventilation set at two levels of continuous positive airway pressure with unrestricted spontaneous breathing. BIVENT can modulate inspiratory effort by modifying the frequency of controlled breaths. Nevertheless, the optimal amount of inspiratory effort to improve respiratory function while minimizing ventilator-associated lung injury during partial ventilatory assis...

  17. Nasal airway nitric oxide : Methodological aspects and influence of inflammation

    OpenAIRE

    Palm, Jörgen

    2004-01-01

    Nitric oxide (NO) is an endogenously formed free radical gas involved in numerous biological processes. In 1991 NO was discovered to be present in exhaled air of humans. Soon after, it was reported that the largest amounts of NO were found in the upper airways, and that the levels of NO were increased in the lower airways of patients with asthma. The high levels of NO in the nasal region are believed to be involved in functions as various as primary host defence, including k...

  18. Does early use of bilevel positive airway pressure (bipap) in cardiothoracic intensive care unit prevent reintubation?

    OpenAIRE

    Sağıroğlu, G; Baysal, A; Çopuroğlu, E; Gül, YG; Karamustafaoğlu, YA; Dogukan, M

    2014-01-01

    Introductıon: Non-invasive ventilation (NIV) is a preferred treatment in acute respiratory failure after operations. Our aim is to investigate the success of early use of bilevel positive airway pressure (BIPAP) after cardiac or thoracic surgeries to prevent reintubation. Methods: In a prospective randomized study, 254 patients were divided into two groups depending on the time period between extubation and the application of BIPAP. In Group 1 BIPAP was applied after extubation within 48 hour...

  19. Adherence to Continuous Positive Airway Pressure Treatment for Obstructive Sleep Apnea: Implications for Future Interventions

    OpenAIRE

    Weaver, Terri E; Sawyer, Amy M.

    2010-01-01

    Adherence to continuous positive airway pressure (CPAP) treatment for obstructive sleep apnea (OSA) is a critical problem with adherence rates ranging from 30–60%. Poor adherence to CPAP is widely recognized as a significant limiting factor in treating OSA, reducing the overall effectiveness of the treatment and leaving many OSA patients at heightened risk for comorbid conditions, impaired function and quality of life. The extant literature examining adherence to CPAP provides critical insigh...

  20. Randomised trial of elective continuous positive airway pressure (CPAP) compared with rescue CPAP after extubation

    OpenAIRE

    Robertson, N; Hamilton, P

    1998-01-01

    AIM—To determine if a weaning regimen on flow driver continuous positive airway pressure (CPAP) would decrease the number of ventilator days but increase the number of CPAP days when compared with a rescue regimen.
METHODS—Fifty eight babies of 24-32 weeks gestation with respiratory distress syndrome (RDS) were studied prospectively. After extubation they were randomly allocated to receive CPAP for 72 hours (n=29) according to a weaning regimen, or were placed in headbox ...

  1. Einflussfaktoren für die Entstehung von Nebenwirkungen unter Therapie mit Continuous Positive Airway Pressure

    OpenAIRE

    Donat, Tina

    2015-01-01

    Continuous positive airway pressure (CPAP) is a common therapy for newborns with respiratory distress syndrome. CPAP can be applied mononasal via nasopharyngeal tubes or binasal via prongs. In addition to mononasal CPAP, binasal CPAP was introduced to the neonatal intensive care unit of Charité Medical Center Berlin Campus Mitte (CCM) in 2003. Adverse effects to CPAP therapy include nasal erythema, skin erosions and necrosis, CPAP-Belly, infection and reintubation. We aimed to (a) investig...

  2. Application of indigenous continuous positive airway pressure during one lung ventilation for thoracic surgery

    OpenAIRE

    Rahul Yadav; Arvind Chaturvedi; Girija Prasad Rath; Keshav Goyal

    2011-01-01

    During one lung ventilation (OLV) hypoxemia may occur due to ventilation-perfusion mismatch. It can be prevented with application of ventilation strategy that prevents atelectasis while minimally impairing perfusion of the dependant lung. Here, two cases are reported who required OLV and in whom hypoxemia could be prevented with the application of continuous positive airway pressure to the deflated or non-dependant lung, using an indigenous technique. We suggest use of this technique which is...

  3. An authentic animal model of the very preterm infant on nasal continuous positive airway pressure

    OpenAIRE

    Dargaville, Peter A.; Lavizzari, Anna; Padoin, Priscila; Black, Don; Zonneveld, Elroy; Perkins, Elizabeth; Sourial, Magdy; Rajapaksa, Anushi E; Davis, Peter G.; Hooper, Stuart B.; Moss, Timothy JM; Polglase, Graeme R.; Tingay, David G.

    2015-01-01

    Background The surge in uptake of nasal continuous positive airway pressure (CPAP) for respiratory support in preterm infants has occurred in the absence of an authentic animal model. Such a model would allow investigation of research questions of physiological and therapeutic importance. We therefore aimed to develop a preterm lamb model of the non-intubated very preterm infant on CPAP. Methods After staged exteriorisation and instrumentation, preterm lambs were delivered from anaesthetised ...

  4. Continuous positive airway pressure increases haemoglobin O2 saturation after acute but not prolonged altitude exposure.

    OpenAIRE

    p. Agostoni, Caldara G, Bussotti M, Revera M, Valentini M, Gregorini F, Faini A, Lombardi C, Bilo G, Giuliano A, Veglia F, Savia G, P.A. Modesti, Mancia G, Parati G

    2010-01-01

    Abstract: It is unknown whether subclinical high-altitude pulmonary oedema reduces spontaneously after prolonged altitude exposure. Continuous positive airway pressure (CPAP) removes extravascular lung fluids and improves haemoglobin oxygen saturation in acute cardiogenic oedema. We evaluated the presence of pulmonary extravascular fluid increase by assessing CPAP effects on haemoglobin oxygen saturation under acute and prolonged altitude exposure. We applied 7 cm H2O CPAP for 30 min to he...

  5. Negative pressure pulmonary edema with laryngeal mask airway use: Recognition, pathophysiology and treatment modalities

    OpenAIRE

    Vandse, Rashmi; Kothari, Deven S; Tripathi, Ravi S; Lopez, Luis; Stawicki, Stanislaw P.A.; Papadimos, Thomas J

    2012-01-01

    Negative pressure pulmonary edema (NPPE) following the use of the laryngeal mask airway (LMA) is an uncommon and under-reported event. We present a case of a 58-year-old male, who developed NPPE following LMA use. After biting vigorously on his LMA, the patient developed stridor upon emergence, with concurrent appearance of blood-tinged, frothy sputum and pulmonary edema. He subsequently required three days of mechanical ventilation. After discontinuation of mechanical ventilation the patient...

  6. New Approaches to Positive Airway Pressure Treatment in Obstructive Sleep Apnea.

    Science.gov (United States)

    Kuźniar, Tomasz J

    2016-06-01

    Continuous positive airway pressure (CPAP) is a mainstay of therapy in patients with obstructive sleep apnea (OSA). This technology has gone through tremendous changes that resulted in devices that can recognize and differentiate sleep-disordered breathing events, adjust their output to these events, monitor usage, and communicate with the treatment team. This article discusses recent developments in treatment of OSA with PAP. PMID:27236053

  7. [Automatic positive airway pressure in titration and treatment of the obstructive sleep apnea syndrome].

    Science.gov (United States)

    Randerath, W J

    2007-04-01

    Although continuous airway pressure therapy (CPAP) represents the standard treatment for obstructive sleep apnea syndrome (OSAS) auto-adjusting CPAP (APAP) devices were developed which adapt the treatment pressure to the actual requirement of the patients. The aim of automatic CPAP therapy is to improve the patients' acceptance of positive pressure treatment. The devices react to respiratory flow, flattening of the inspiratory flow contour, snoring, generator speed or the upper airway impedance. In recent years several studies showed that auto CPAP effectively treats respiratory disturbances, improves sleep profile and the self-assessment of the patients equally as good as the gold standard constant CPAP. Moreover, APAP reduces the treatment pressure substantially. Although an improvement of the patient's compliance has not consistently been proven, most patients prefer APAP versus constant CPAP. APAP devices use different algorithms depending on the primary purpose of the application. Therefore, a clear distinction between automatic titration and treatment is of major relevance. While titration devices aim at the finding of one single pressure which is fixed to a constant CPAP device, automatic treatment means the chronic use of APAP at home for optimal adaptation of the treatment pressure to the actual requirements of the patient. A high constant CPAP level, huge pressure variability, insufficient compliance with constant CPAP may be indications for APAP treatment. The main reason for automatic titration is the standardisation of the initiation process. PMID:17455137

  8. 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.

  9. 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

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

    OpenAIRE

    C.B.F. Pantoni; L. Di Thommazo; R.G. Mendes; A.M. Catai; Luzzi, S.; O. Amaral Neto; A. Borghi-Silva

    2011-01-01

    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 a...

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

    Science.gov (United States)

    George, Lovya; Jain, Sunil K.

    2015-01-01

    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. PMID:26495158

  12. 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.

  13. Use of Biphasic Continuous Positive Airway Pressure in Premature Infant with Cleft Lip-Cleft Palate.

    Science.gov (United States)

    George, Lovya; Jain, Sunil K

    2015-10-01

    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. PMID:26495158

  14. Effect of continuous cuff pressure regulator in general anaesthesia with laryngeal mask airway.

    Science.gov (United States)

    Jeon, Y-S; Choi, J-W; Jung, H-S; Kim, Y-S; Kim, D-W; Kim, J-H; Lee, J-A

    2011-01-01

    Postoperative pharyngolaryngeal complications (PPLC) occur during anaesthesia due to increased cuff pressure following the insertion of laryngeal mask airways. The use of a pressure regulator to prevent PPLC was evaluated in a prospective, randomized study. Sixty patients scheduled to receive general anaesthesia were randomly assigned to two equal groups of 30, either with or without the regulator. The 'just seal' cuff pressure (JSCP), cuff pressure at 5-min intervals during anaesthesia, incidence of pharyngeal sore throat (PST), dysphagia, dysphonia and other complications were evaluated at 1 and 24 h postoperatively. The combined mean ± SD JSCP of both groups was 20.3 ± 3.2 mmHg. In the group with the regulator, cuff pressure was maintained at a constant level during anaesthesia. This study demonstrated that the regulator is a simple, functional device that can reduce the incidence of PST significantly at 1 h postoperatively, following general anaesthesia. PMID:22117992

  15. Effect of reduced expiratory pressure on pharyngeal size during nasal positive airway pressure in patients with sleep apnoea: evaluation by continuous computed tomography.

    OpenAIRE

    Gugger, M.; Vock, P

    1992-01-01

    BACKGROUND: This study aimed to determine whether reducing the expiratory pressure during nasal positive airway pressure for reasons of comfort causes a substantial decrease in the upper airway calibre. METHODS: Eight patients with obstructive sleep apnoea were studied. Continuous computed tomography (each run lasting 12 seconds) was used to measure minimum and maximum pharyngeal cross sectional areas at the velopharynx and the hypopharynx. Pharyngeal areas were measured while patients were a...

  16. Hemodynamic effects of pressures applied to the upper airway during sleep.

    Science.gov (United States)

    Eastwood, P R; Curran, A K; Smith, C A; Dempsey, J A

    2000-08-01

    The increase in systemic blood pressure after an obstructive apnea is due, in part, to sympathetically mediated vasoconstriction. We questioned whether upper airway (UA) receptors could contribute reflexly to this vasoconstriction. Four unanesthetized dogs were studied during wakefulness and non-rapid-eye-movement (NREM) sleep. The dogs breathed via a fenestrated tracheostomy tube sealed around the tracheal stoma. The snout was sealed with an airtight mask, thereby isolating the UA when the fenestration was closed and exposing the UA to negative inspiratory intrathoracic pressure when it was open. The blood pressure response to three UA perturbations was studied: 1) square-wave negative pressures sufficient to cause UA collapse with the fenestration closed during a mechanical hyperventilation-induced central apnea; 2) tracheal occlusion with the fenestration open vs. closed; and 3) high-frequency pressure oscillations (HFPO) with the fenestration closed. During NREM sleep, 1) blood pressure response to tracheal occlusion was similar with the fenestration open or closed; 2) collapsing the UA with negative pressures failed to alter blood pressure during a central apnea; and 3) application of HFPO to the UA during eupnea and resistive-loaded breaths increased heart rate and blood pressure. However, these changes were likely to be secondary to the effects of HFPO-induced reflex changes on prolonging expiratory time. These findings suggest that activation of UA pressure-sensitive receptors does not contribute directly to the pressor response associated with sleep-disordered breathing events. PMID:10926636

  17. Long-Term Continuous Positive Airway Pressure Therapy Normalizes High Exhaled Nitric Oxide Levels in Obstructive Sleep Apnea

    Science.gov (United States)

    Chua, Ai-Ping; Aboussouan, Loutfi S.; Minai, Omar A.; Paschke, Kelly; Laskowski, Daniel; Dweik, Raed A.

    2013-01-01

    Study Objectives: Upper airway inflammation and oxidative stress have been implicated in the pathogenesis of obstructive sleep apnea (OSA) and may be linked to cardiovascular consequences. We prospectively examined fraction of exhaled nitric oxide (FENO), a surrogate marker of upper airway inflammation using a portable nitric oxide analyzer (NIOX MINO). Design: In consecutive adult nonsmokers with suspected OSA, FENO was measured immediately before and after polysomnographic studies, and within 1-3 months following continuous positive airway pressure (CPAP) therapy. Measurement and Results: FENO levels were increased in the 75 patients with OSA compared to the 29 controls, both before sleep (13.4 ± 6.5 ppb vs. 6.5 ± 3.5; p Paschke K; Laskowski D; Dweik RA. Long-term continuous positive airway pressure therapy normalizes high exhaled nitric oxide levels in obstructive sleep apnea. J Clin Sleep Med 2013;9(6):529-535. PMID:23772184

  18. Clinical predictors of central sleep apnea evoked by positive airway pressure titration

    Science.gov (United States)

    Moro, Marilyn; Gannon, Karen; Lovell, Kathy; Merlino, Margaret; Mojica, James; Bianchi, Matt T

    2016-01-01

    Purpose Treatment-emergent central sleep apnea (TECSA), also called complex apnea, occurs in 5%–15% of sleep apnea patients during positive airway pressure (PAP) therapy, but the clinical predictors are not well understood. The goal of this study was to explore possible predictors in a clinical sleep laboratory cohort, which may highlight those at risk during clinical management. Methods We retrospectively analyzed 728 patients who underwent PAP titration (n=422 split-night; n=306 two-night). Demographics and self-reported medical comorbidities, medications, and behaviors as well as standard physiological parameters from the polysomnography (PSG) data were analyzed. We used regression analysis to assess predictors of binary presence or absence of central apnea index (CAI) ≥5 during split-night PSG (SN-PSG) versus full-night PSG (FN-PSG) titrations. Results CAI ≥5 was present in 24.2% of SN-PSG and 11.4% of FN-PSG patients during titration. Male sex, maximum continuous positive airway pressure, and use of bilevel positive airway pressure were predictors of TECSA, and rapid eye movement dominance was a negative predictor, for both SN-PSG and FN-PSG patients. Self-reported narcotics were a positive predictor of TECSA, and the time spent in stage N2 sleep was a negative predictor only for SN-PSG patients. Self-reported history of stroke and the CAI during the diagnostic recording predicted TECSA only for FN-PSG patients. Conclusion Clinical predictors of treatment-evoked central apnea spanned demographic, medical history, sleep physiology, and titration factors. Improved predictive models may be increasingly important as diagnostic and therapeutic modalities move away from the laboratory setting, even as PSG remains the gold standard for characterizing primary central apnea and TECSA. PMID:27555802

  19. Should Airway Pressure Release Ventilation Be the Primary Mode in ARDS?

    Science.gov (United States)

    Mireles-Cabodevila, Eduardo; Kacmarek, Robert M

    2016-06-01

    Airway pressure release ventilation (APRV) was originally described as a mode to treat lung-injured patients with the goal to maintain a level of airway pressure that would not depress the cardiac function, deliver mechanical breaths without excessive airway pressure, and to allow unrestricted spontaneous ventilation. Indeed, based on its design, APRV has technological features that serve the goals of safety and comfort. Animal studies suggest that APRV leads to alveolar stability and recruitment which result in less lung injury. These features are sought in patients at risk for lung injury or with ARDS. APRV allows unrestricted spontaneous ventilation, which is welcome in the era of less sedation and increased patient mobility (the effects in terms of lung injury remain to be explored). However, we must highlight that the performance of APRV is dependent on the operator-selected settings and the ventilator's performance. The clinician must select the appropriate settings in order to make effective the imputed benefits. This is a challenge when the ventilator's performance is not uniform, and the outcomes depend on high precision settings (very short expiratory time), where small variations can lead to undesired outcomes (de-recruitment or large tidal volumes leading to lung injury). Finally, we do not have evidence that APRV (as originally described) improves relevant clinical outcomes of patients with ARDS. For APRV to become the primary mode of ventilation for ARDS, it will require development of sound protocols and technological enhancements to ensure its performance and safety. For now, APRV does have a greater potential for adversely affecting patient outcome than improving it; unless definitive data are forthcoming demonstrating outcome benefits from the use of APRV in ARDS, there is no reason to consider this approach to ventilatory support. PMID:27235312

  20. Comparison of 3 titration methods of positive airway pressure for obstructive sleep apnea syndrome: a random, single-blind and self-control clinical study

    OpenAIRE

    LI Yan; Liu, Xin-Xin; Wan-er WANG; Wang, Yang; Gao, He

    2013-01-01

    Objective  To evaluate the efficacy and safety of polysomnography-manual continuous positive airway pressure titration (PSG-CPAP), polysomnography-automatic positive airway pressure titration (PSG-APAP), or automatic positive airway pressure titration (APAP) in patients with moderate or severe simple obstructive sleep apnea syndrome (OSAS). Methods  Twenty patients with moderate or severe OSAS sequentially underwent PSG-CPAP, PSG-APAP and APAP titration 3 days apart, and then 3 primary effica...

  1. 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

    OpenAIRE

    Sandeep Kumar Mishra; Mohammad Nawaz; Satyapraksh, M. V. S.; Satyen Parida; Prasanna Udupi Bidkar; Balachander Hemavathy; Pankaj Kundra

    2015-01-01

    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 l...

  2. Continuous positive airway pressure and ventilation are more effective with a nasal mask than a full face mask in unconscious subjects: a randomized controlled trial

    OpenAIRE

    Oto, Jun; Li, Qian; Kimball, William R; Wang, Jingping; Sabouri, Abdolnabi S; Harrell, Priscilla G.; Robert M Kacmarek; Jiang, Yandong

    2013-01-01

    Introduction Upper airway obstruction (UAO) is a major problem in unconscious subjects, making full face mask ventilation difficult. The mechanism of UAO in unconscious subjects shares many similarities with that of obstructive sleep apnea (OSA), especially the hypotonic upper airway seen during rapid eye movement sleep. Continuous positive airway pressure (CPAP) via nasal mask is more effective at maintaining airway patency than a full face mask in patients with OSA. We hypothesized that CPA...

  3. High Altitude, Continuous Positive Airway Pressure, and Obstructive Sleep Apnea: Subjective Observations and Objective Data

    OpenAIRE

    Ginosar, Yehuda; Malhotra, Atul; Schwartz, Eli

    2013-01-01

    Ginosar, Yehuda, Atul Malhotra, and Eli Schwartz. High altitude, continuous positive airway pressure, and obstructive sleep apnea: Subjective observations and objective data. High Alt Med Biol 14:186–189, 2013.—We report observations made by one of the authors who ascended to the Thorang La pass (5416 m) in the Nepal Himalaya in October 2010, despite moderate-severe obstructive sleep apnea. We report the first recorded use of nasal CPAP to treat high altitude pulmonary edema (progressively se...

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

    OpenAIRE

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

    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...

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

    DEFF Research Database (Denmark)

    Lamberts, M.; Nielsen, O. W.; Lip, G. Y. H.; Ruwald, M. H.; Christiansen, C. B.; Kristensen, S. L.; Torp-Pedersen, Christian; Hansen, M. L.; Gislason, G. 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. First-time......% men) of whom 44% received persistent CPAP therapy. Median time to initiation of CPAP therapy was 88 days (interquartile range 34-346). Patients with sleep apnoea had more comorbidities compared to the general population. Crude rates of MI and ischaemic stroke were increased for sleep apnoea patients...

  6. 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

  7. Effect of HFNC flow rate, cannula size, and nares diameter on generated airway pressures: an in vitro study.

    Science.gov (United States)

    Sivieri, Emidio M; Gerdes, Jeffrey S; Abbasi, Soraya

    2013-05-01

    Increased use of non-invasive forms of respiratory support such as CPAP and HFNC in premature infants has generated a need for further investigation of the pulmonary effects of such therapies. In a series of in vitro tests, we measured delivered proximal airway pressures from a HFNC system while varying both the cannula flow and the ratio of nasal prong to simulated nares diameters. Neonatal and infant sized nasal prongs (3.0 and 3.7 mm O.D.) were inserted into seven sizes of simulated nares (range: 3-7 mm I.D. from anatomical measurements in 1-3 kg infants) for nasal prong-to-nares ratios ranging from 0.43 to 1.06. The nares were connected to an active test lung set at: TV 10 ml, 60 breaths/min, Ti 0.35 sec, compliance 1.6 ml/cm H₂O and airway resistance 70 cm H₂O/(L/sec), simulating a 1-3 kg infant with moderately affected lungs. A Fisher & Paykel Healthcare HFNC system with integrated pressure relief valve was set to flow rates of 1-6 L/min while cannula and airway pressures and cannula and mouth leak flows were measured during simulated mouth open, partially closed and fully closed conditions. Airway pressure progressively increased with both increasing HFNC flow rate and nasal prong-to-nares ratio. At 6 L/min HFNC flow with mouth open, airway pressures remained 0.9 and 50% mouth leak, airway pressures rapidly increased to 18 cm H₂O at 2 L/min HFNC flow followed by a pressure relief valve limited increase to 24 cm H₂O at 6 L/min. Safe and effective use of HFNC requires careful selection of an appropriate nasal prong-to-nares ratio even with an integrated pressure relief valve. PMID:22825878

  8. 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.

  9. 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

  10. An investigation of the influence of cell topography on epithelial mechanical stresses during pulmonary airway reopening

    Science.gov (United States)

    Jacob, A. M.; Gaver, D. P.

    2005-03-01

    The goal of this study is to assess the local mechanical environment of the pulmonary epithelium in a computational model of airway reopening. To this end, the boundary element method (BEM) in conjunction with lubrication theory is implemented to assess the stationary-state behavior of a semi-infinite bubble traveling through a liquid-occluded parallel plate flow chamber lined with epithelial cells. The fluid occlusion is assumed to be Newtonian and inertia is neglected. The interactions between the microgeometry of the model airway's walls and the interfacial kinematics surrounding the bubble's tip result in a complex, spatially and temporally dependent stress distribution. The walls' nonplanar topography magnifies the normal and shear stresses and stress gradients. We find that decreasing the bubble's speed serves to increase the maximum normal stress and stress gradient but decrease the maximum shear stress and stress gradient. Our results give credence to the pressure-gradient-induced epithelial damage theory recently proposed by Bilek et al. [J. Appl. Physiol. 94, 770 (2003)] and Kay et al. [J. Appl. Physiol. 97, 269 (2004)]. We conclude that the amplified pressure gradients found in this study may be even more detrimental to the airway's cellular epithelium during airway reopening.

  11. The usage of the Boussignac continuous positive airway pressure system in acute respiratory failure.

    Science.gov (United States)

    Wong, D T; Tam, A D; Van Zundert, T C R V

    2013-05-01

    Traditionally, continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP) devices have been used to treat patients in acute respiratory failure. However they require an electric power source, are relatively large in size, and may be difficult to use in prehospital settings. The recently introduced Boussignac CPAP system is capable of delivering 10 cmH2O of CPAP, is compact, portable and requires only an oxygen source. This paper reviews the efficacy of using Boussignac CPAP as a treatment for acute respiratory failure in both prehospital and hospital settings. All studies mainly focused on patients treated for cardiogenic pulmonary edema. In the prehospital setting, Boussigac CPAP significantly improved respiratory parameters and oxygenation from baseline values. In the emergency department setting, Boussignac CPAP was more effective than standard oxygen delivery and just as effective as BiPAP in improving patient oxygenation and respiration. In one study, implementing Boussignac CPAP reduced intubation rate and hospital stay. Most hospital staff found Boussignac CPAP easy to use and complication rates were low. Boussigac CPAP is a useful device in the treatment of patients with acute respiratory failure, especially in the prehospital setting. PMID:23419338

  12. 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.

  13. Comparison of the effects of continuous positive airway pressure, oral appliance and exercise training in obstructive sleep apnea syndrome

    Directory of Open Access Journals (Sweden)

    Teresa Cristina Barros Schutz

    2013-01-01

    Full Text Available OBJECTIVE: There are several treatments for obstructive sleep apnea syndrome, such as weight loss, use of an oral appliance and continuous positive airway pressure, that can be used to reduce the signs and symptoms of obstructive sleep apnea syndrome. Few studies have evaluated the effectiveness of a physical training program compared with other treatments. The aim of this study was to assess the effects of physical exercise on subjective and objective sleep parameters, quality of life and mood in obstructive sleep apnea patients and to compare these effects with the effects of continuous positive airway pressure and oral appliance treatments. METHODS: Male patients with moderate to severe obstructive sleep apnea and body mass indices less than 30 kg/m2 were randomly assigned to three groups: continuous positive airway pressure (n = 9, oral appliance (n = 9 and physical exercise (n = 7. Polysomnographic recordings, blood samples and daytime sleepiness measurements were obtained prior to and after two months of physical exercise or treatment with continuous positive airway pressure or an oral appliance. Clinicaltrials.gov: NCT01289392 RESULTS: After treatment with continuous positive airway pressure or an oral appliance, the patients presented with a significant reduction in the apnea-hypopnea index. We did not observe changes in the sleep parameters studied in the physical exercise group. However, this group presented reductions in the following parameters: T leukocytes, very-low-density lipoprotein and triglycerides. Two months of exercise training also had a positive impact on subjective daytime sleepiness. CONCLUSIONS: Our results suggest that isolated physical exercise training was able to modify only subjective daytime sleepiness and some blood measures. Continuous positive airway pressure and oral appliances modified the apnea-hypopnea index.

  14. Histopathologic pulmonary changes from mechanical ventilation at high peak airway pressures.

    Science.gov (United States)

    Tsuno, K; Miura, K; Takeya, M; Kolobow, T; Morioka, T

    1991-05-01

    We investigated the histopathologic pulmonary changes induced by mechanical pulmonary ventilation (MV) with a high peak airway pressure and a large tidal volume in healthy baby pigs. Eleven animals were mechanically ventilated at a peak inspiratory pressure (PIP) of 40 cm H2O, a respiratory rate (RR) of 20 min-1, a positive end-expiratory pressure (PEEP) of 3 to 5 cm H2O, and an FIO2 of 0.4. High airway pressure MV was terminated in 22 +/- 11 h because of severe hypoxemia in the animals. Five of the baby pigs were killed for gross and light microscope studies. The pulmonary changes consisted of alveolar hemorrhage, alveolar neutrophil infiltration, alveolar macrophage and type II pneumocyte proliferation, interstitial congestion and thickening, interstitial lymphocyte infiltration, emphysematous change, and hyaline membrane formation. Those lesions were similar to that seen in the early stage of the adult respiratory distress syndrome (ARDS). The remaining six animals were treated for 3 to 6 days with conventional respiratory care with appropriate ventilator settings. Prominent organized alveolar exudate in addition to lesions was also found in the five animals. These findings were indistinguishable from the clinical late stage of ARDS. Six control animals were mechanically ventilated at a PIP of less than 18 cm H2O, a RR of 20 min-1, a PEEP of 3 to 5 cm H2O, and an FIO2 of 0.4 for 48 h. They showed no notable changes in lung functions and histopathologic findings. Aggressive MV with a high PIP is often applied to patients with respiratory distress to attain adequate pulmonary gas exchange.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2024823

  15. Treatment of sleep-disordered breathing with positive airway pressure devices: technology update

    Directory of Open Access Journals (Sweden)

    Johnson KG

    2015-10-01

    Full Text Available Karin Gardner Johnson, Douglas Clark Johnson Department of Medicine, Baystate Medical Center, Springfield, MA, USA Abstract: Many types of positive airway pressure (PAP devices are used to treat sleep-disordered breathing including obstructive sleep apnea, central sleep apnea, and sleep-related hypoventilation. These include continuous PAP, autoadjusting CPAP, bilevel PAP, adaptive servoventilation, and volume-assured pressure support. Noninvasive PAP has significant leak by design, which these devices adjust for in different manners. Algorithms to provide pressure, detect events, and respond to events vary greatly between the types of devices, and vary among the same category between companies and different models by the same company. Many devices include features designed to improve effectiveness and patient comfort. Data collection systems can track compliance, pressure, leak, and efficacy. Understanding how each device works allows the clinician to better select the best device and settings for a given patient. This paper reviews PAP devices, including their algorithms, settings, and features. Keywords: BiPAP, CPAP, iVAPS, AVAPS, ASV, positive pressure respiration, instrumentation, treatment algorithm

  16. Early Bubble Continuous Positive Airway Pressure: Investigating Interprofessional Best Practices for the NICU Team.

    Science.gov (United States)

    Casey, Jessica L; Newberry, Desi; Jnah, Amy

    2016-01-01

    Premature neonates delivered alveolar instability and collapse can cause decreased functional residual capacity, impaired oxygenation, and hypoxemia leading to respiratory distress syndrome. Supportive measures are indicated immediately after birth to establish physiologic stability including bubble continuous positive airway pressure (CPAP) or endotracheal intubation and mechanical ventilation. CPAP is a noninvasive, gentle mode of ventilation that can mitigate the effects of lung immaturity, but prolonged use can increase the risk for nasal breakdown. Strategies to mitigate this risk must be infused as best practices in the NICU environment. The purpose of this article is to propose an evidence-based best practice care bundle for the early initiation of CPAP in the delivery room and associated skin barrier protection strategies for premature neonates <32 weeks gestation and weighing <1,500 g. PMID:27194606

  17. Investigation of the hygienic safety of continuous positive airways pressure devices after reprocessing.

    Science.gov (United States)

    Steinhauer, K; Goroncy-Bermes, P

    2005-10-01

    With the widespread use of continuous positive airways pressure (CPAP) therapy, the safety of CPAP devices after reprocessing is the subject of debate. In this study, the contamination of CPAP devices and the effectiveness of disinfection was investigated. A total of 122 CPAP devices were examined including 50 CPAP devices used by patients, which were examined before and after reprocessing. Seventy-two new CPAP devices that had not been in contact with patients served as controls. The results of this study show that the microbial contamination of new and used CPAP devices is only minimal. Contaminating micro-organisms were predominantly micro-organisms reflecting the normal environmental microflora such as Penicillium spp., Aspergillus spp., Micrococcaceae and Bacillaceae. Gram-negative species could only be found in rare cases. The data obtained give no indication of poor disinfection of CPAP devices. PMID:16023258

  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...... unit length of stay, and intubation rate. We undertook a systematic review based on a search in the three databases: PubMed, EMBASE, and Cochrane. We included 12 studies in our review, but only four of these were of acceptable size and quality to conclude on our endpoints of interest. All four studies...... 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. Standardized weaning of infants <32 weeks of gestation from continuous positive airway pressure - a feasibility study.

    Science.gov (United States)

    Kidszun, André; Plate, Maren; Arnold, Christine; Winter, Julia; Gerhold-Ay, Aslihan; Mildenberger, Eva

    2016-10-01

    The practice of weaning premature infants from continuous positive airway pressure (CPAP) varies considerably and is usually performed without written standards. In this study, the feasibility of a standardized weaning approach was evaluated. In a quasi-experimental design, data from a prospective, post-intervention cohort (n=41) were compared to data from a pre-intervention cohort (n=36). Standardized weaning was feasible but no significant differences in short-term respiratory outcomes were observed. Weaning from CPAP was achieved at 32.1 ± 1.6 (post-intervention) versus 32.5 ± 2.3 weeks (pre-intervention) postmenstrual age. More rigorous, large-scale clinical trials are necessary before firm recommendations on distinct weaning regimens can be made. PMID:26552715

  20. Treatment of presumed acute cardiogenic pulmonary oedema in an ambulance system by nurses using Boussignac continuous positive airway pressure

    NARCIS (Netherlands)

    Dieperink, Willem; Weelink, E. E. M.; van der Horst, I. C. C.; de Vos, R.; Jaarsma, T.; Aarts, L. P. H. J.; Zijlstra, F.; Nijsten, M. W. N.

    2009-01-01

    Background: Early initiation of continuous positive airway pressure (CPAP) applied by face mask benefits patients with acute cardiogenic pulmonary oedema (ACPE). The simple disposable Boussignac CPAP (BCPAP) has been used in ambulances by physicians. In the Netherlands, ambulances are manned by nurs

  1. 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

  2. The relationship between early reversibility test and maximal inspiratory pressure in patients with airway obstruction

    Directory of Open Access Journals (Sweden)

    Ozkaya S

    2014-05-01

    Full Text Available Sevket Ozkaya,1 Adem Dirican,2 Sule Ozbay Kaya,3 Rabia C Karanfil,3 Merve G Bayrak,4 Ozgür Bostancı,5 Ferah Ece1 1Department of Pulmonary Medicine, Faculty of Medicine, Bahcesehir University, Istanbul, 2Department of Pulmonary Medicine, 3Department of Physical Therapy and Rehabilitation Clinic, Samsun Medicalpark Hospital, 4Department of Pulmonary Medicine, Samsun Chest Diseases and Thoracic Surgery Hospital, 5Academy of Sports, Ondokuzmayis University, Samsun, Turkey Abstract: Maximal inspiratory pressure (MIP is a marker for assessing the degree of respiratory muscle dysfunction. Muscle dysfunction represents a pathophysiological feature of chronic obstructive pulmonary disease. We aimed to determinate the MIP value in patients with airway obstruction, to evaluate the change in MIP with bronchodilator drug, and to show the relationship between the changes in MIP and disease characteristics. We evaluated 21 patients with airway obstruction at the Department of Pulmonary Medicine, Samsun Medicalpark Hospital, Samsun, Turkey. We performed pulmonary function tests, measurement of MIP values, and reversibility tests with salbutamol. The baseline spirometry results were: mean forced vital capacity (FVC, 3,017±1,020 mL and 75.8%±20.8%; mean forced expiratory volume in 1 second (FEV1, 1,892±701 mL and 59.2%±18.2%; FEV1/FVC, 62.9%±5.5%; peak expiratory flow, 53%±19%. The pre-bronchodilator MIP value was 62.1±36.9 cmH2O. The reversibility test was found to be positive in 61.9% of patients with salbutamol. The absolute change and percentage of change in FEV1 were 318±223 mL and 19.8%±16.7%, respectively. The MIP value was increased by 5.5 cmH2O (8.8% and was 67.7±30.3 cmH2O after bronchodilation. There was no significant relationship between age, FEV1, reversibility, and change in MIP with bronchodilator. However, the increase in MIP with bronchodilator drug was higher in patients with low body mass index (<25 kg/m2. We noted a 13.1% increase

  3. Die Ventilation mit biphasic positive airway pressure (BIPAP) im experimentellen akuten Lungenschaden : der Einfluß des transpulmonalen Drucks auf Gasaustausch und Hämodynamik

    OpenAIRE

    Hatam, Nima

    2009-01-01

    OBJECTIVE: We investigated whether improvement in ventilation perfusion distribution during mechanical ventilation using biphasic positive airway pressure (BIPAP) with spontaneous breathing may be attributed to an effectively increased transpulmonary pressure (PTP) and can also be achieved by increasing PTP during controlled ventilation. DESIGN: In 12 pigs with saline lavage-induced lung injury we compared the effects of BIPAP to pressure-controlled ventilation with equal airway pressure (PCV...

  4. 不同压力滴定技术对重度阻塞性睡眠呼吸暂停低通气综合征患者正压通气效果的影响%Influence of different methods of CPAP pressure titration on effect of serious obstructive sleep apnea hypopnea syndrome treated with continuous positive airway pressure

    Institute of Scientific and Technical Information of China (English)

    田松焕; 王凯

    2014-01-01

    目的 探讨不同压力滴定技术对重度阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea hypopnea syndrome,OSAHS)患者使用经鼻持续气道正压通气(continuous positive airway pressure,CPAP)治疗效果的影响.方法 将60例愿意接受CPAP治疗的重度OSAHS患者随机分为实验组和对照组各30例,实验组使用标准实验室手工压力滴定技术;对照组使用自动压力滴定技术.所有患者压力滴定前均进行CPAP治疗相关知识教育.两组接受CPAP治疗前和治疗后6个月进行SAQLI生活质量量表评分及嗜睡评分,并对比呼吸机使用情况及多导睡眠图(polysomnography,PSG)各项参数.结果 实验组生活质量改善程度明显高于对照组;实验组呼吸机使用天数、平均每天使用时间、呼吸暂停低通气指数(AHI)、最低血氧饱和度(LSAT)、<90%的氧减时间等各项参数较对照组明显改善(P<0.05).结论 标准实验室手工压力滴定技术可以显著提高重度阻塞性睡眠呼吸暂停低通气综合征患者持续气道正压通气治疗效果.

  5. Volume, flow, and timing of each breath during negative airway pressure in humans.

    Science.gov (United States)

    Hirsch, J A; Bishop, B

    1981-03-01

    We have analyzed the effects of 4-6 min of 5, 10 and 15 cmH2O continuous negative airway pressure breathing (NPB) on steady-state end-expiratory lung volume (delta VR) and breathing pattern. Fourteen healthy adults, seated in a full body box, breathed via a mouthpiece on a bag-in-box. Pressure in the body box was elevated to the desired pressure level. Inspiratory (TI) and expiratory (TE) durations, tidal volume (VT), minute ventilation (VI), mean inspiratory flow (VT/TI), and mean expiratory flow (VT/TE) were calculated from pneumotachometer recordings. The effects of NPB are decreases in delta VR, VT, and VT/TI and increases in VT/TE. The responses to NPB are an increase in breathing frequency, due to a shortened TE, and an increase in inspiratory activity. The decrease in delta VR and the increase in VT/TE are limited by an active retardation of expiratory flow. End-tidal CO2 and VI were not altered significantly during NPB, suggesting no alveolar hyperventilation. Thus multiple components of the human response to NPB are not all engaged at the same levels of NPB. The changes in the timing of respiratory events occur at -5 cmH2O, whereas VT compensation is not seen until -15 cmH2O. PMID:6788735

  6. Breathing pattern in humans: elevated CO2 or low O2 on positive airway pressure.

    Science.gov (United States)

    Hirsch, J A; Bishop, B

    1984-03-01

    The purpose of this study was to determine effects on breathing pattern of pressure breathing alone and in combination with chemical stimulation. We analyzed ventilatory responses to elevated airway pressures (positive-pressure breathing, PPB) in subjects breathing air, 12% O2, or elevated CO2. Each subject sat in a body box and breathed via mouth-piece from a bag-in-box. Responses to PPB on air were increased minute ventilation (VI), tidal volume (VT), frequency (f), mean inspiratory (VT/TI) and expiratory (VT/TE) flows, decreased expiratory duration (TE) and end-tidal CO2. If end-tidal CO2 were held constant, VI, VT, and VT/TI increased less. Responses greater than predicted from summing responses to either stimulus alone were observed for VT, f, VT/TI, and VT/TE during 3 and 5% CO2 and for VT, f, and VT/TE during isocapnic hypoxia. Responses to other combined stimuli were sums of responses to the individual stimuli. Thus ventilatory responses to combined PPB and chemical stimuli cannot be predicted simply from summating responses to each independently imposed stimulus, suggesting that sensory information arises from and is integrated at multiple sites. PMID:6423592

  7. Effect of upper airway negative pressure on inspiratory drive during sleep.

    Science.gov (United States)

    Eastwood, P R; Curran, A K; Smith, C A; Dempsey, J A

    1998-03-01

    To determine the effect of upper airway (UA) negative pressure and collapse during inspiration on regulation of breathing, we studied four unanesthetized female dogs during wakefulness and sleep while they breathed via a fenestrated tracheostomy tube, which was sealed around the permanent tracheal stoma. The snout was sealed with an airtight mask, thereby isolating the UA when the fenestration (Fen) was closed and exposing the UA to intrathoracic pressure changes, but not to flow changes, when Fen was open. During tracheal occlusion with Fen closed, inspiratory time (TI) increased during wakefulness, non-rapid-eye-movement (NREM) sleep and rapid-eye-movement (REM) sleep (155 +/- 8, 164 +/- 11, and 161 +/- 32%, respectively), reflecting the removal of inhibitory lung inflation reflexes. During tracheal occlusion with Fen open (vs. Fen closed): 1) the UA remained patent; 2) TI further increased during wakefulness and NREM (215 +/- 52 and 197 +/- 28%, respectively) but nonsignificantly during REM sleep (196 +/- 42%); 3) mean rate of rise of diaphragm EMG (EMGdi/TI) and rate of fall of tracheal pressure (Ptr/TI) were decreased, reflecting an additional inhibitory input from UA receptors; and 4) both EMGdi/TI and Ptr/TI were decreased proportionately more as inspiration proceeded, suggesting greater reflex inhibition later in the effort. Similar inhibitory effects of exposing the UA to negative pressure (via an open tracheal Fen) were seen when an inspiratory resistive load was applied over several breaths during wakefulness and sleep. These inhibitory effects persisted even in the face of rising chemical stimuli. This inhibition of inspiratory motor output is alinear within an inspiration and reflects the activation of UA pressure-sensitive receptors by UA distortion, with greater distortion possibly occurring later in the effort. PMID:9480970

  8. Continuous positive airway pressure therapy reduces oxidative stress markers and blood pressure in sleep apnea-hypopnea syndrome patients.

    Science.gov (United States)

    Murri, Mora; García-Delgado, Regina; Alcázar-Ramírez, José; Fernández de Rota, Luis; Fernández-Ramos, Ana; Cardona, Fernando; Tinahones, Francisco J

    2011-12-01

    Sleep apnea-hypopnea syndrome (SAHS) is characterized by recurrent episodes of hypoxia/reoxygenation, which seems to promote oxidative stress. SAHS patients experience increases in hypertension, obesity and insulin resistance (IR). The purpose was to evaluate in SAHS patients the effects of 1 month of treatment with continuous positive airway pressure (CPAP) on oxidative stress and the association between oxidative stress and insulin resistance and blood pressure (BP). Twenty-six SAHS patients requiring CPAP were enrolled. Measurements were recorded before and 1 month after treatment. Cellular oxidative stress parameters were notably decreased after CPAP. Intracellular glutathione and mitochondrial membrane potential increased significantly. Also, total antioxidant capacity and most of the plasma antioxidant activities increased significantly. Significant decreases were seen in BP. Negative correlations were observed between SAHS severity and markers of protection against oxidative stress. BP correlated with oxidative stress markers. In conclusion, we observed an obvious improvement in oxidative stress and found that it was accompanied by an evident decrease in BP with no modification in IR. Consequently, we believe that the decrease in oxidative stress after 1 month of CPAP treatment in these patients is not contributing much to IR genesis, though it could be related to the hypertension etiology. PMID:21286851

  9. 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.

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

    Science.gov (United States)

    Wakayama, Tadashi; Suzuki, Masaaki; Tanuma, Tadashi

    2016-01-01

    Objective 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. Methods 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. Results 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. Conclusion 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

  11. Effect of continuous positive airway pressure on blood pressure in hypertensive patients with coronary artery bypass grafting and obstructive sleep apnea

    OpenAIRE

    Dong, Yumei; Dai, Yingnan; Wei, Guoqian; Cha, Li; Li, Xueqi

    2014-01-01

    Background: Previous studies have documented that obstructive sleep apnea (OSA) increases the incidence of hypertension, respiratory failure and unexpected post-operative deaths during night in coronary artery bypass grafting (CABG) patients. We hypothesized that continuous positive airway pressure (CPAP) reduces blood pressure in these patients. Methods: We conducted a prospective, controlled study in 51 patients. The subjects received CPAP treatment were defined as CPAP group, whereas those...

  12. Lung recruitment can improve oxygenation in patients ventilated in continuous positive airway pressure/pressure support mode

    Directory of Open Access Journals (Sweden)

    András eLovas

    2015-04-01

    Full Text Available Background: Recruitment maneuvers are often used in critical care patients with hypoxemic respiratory failure. Although continuous positive airway pressure/pressure support (CPAP/PS ventilation is a frequently used approach, but whether lung recruitment also improves oxygenation in spontaneously breathing patients has not been investigated yet. The primary objective was to analyse the effect of recruitment maneuver on oxygenation in patients ventilated in CPAP/PS mode. Methods: Following baseline measurements PEEP was increased by 5 cmH2O. Recruitment maneuver was applied for 40 seconds with 40 cmH2O of PS. Measurements of the difference in PaO2/FiO2 and airway parameters measured by the ventilator were recorded immediately after recruitment then 15 and 30 minutes later. Thirty patients ventilated in CPAP/PS mode with a PEEP ≥ 5 cmH2O were enrolled in this prospective, observational study if their PaO2/FiO2 ratio was 0.5. Results: Following recruitment maneuver patients were considered as non-responders (NR, n=15 if difference of PaO2/FiO2 < 20 % and responders (R, n=15 if difference of PaO2/FiO2 ≥ 20 %. In the NR-group PaO2/FiO2 decreased non-significantly from baseline: median [interquartile], PaO2/FiO2 = 176 [120-186] vs. after recruitment: 169 [121-182] mmHg, P = .307 while in the R-group there was significant improvement: 139 [117-164] vs. 230 [211-323] mmHg, P = .01. At the same time points dead space to tidal volume ratio (Vds/Vte significantly increased in the NR-group Vds/Vte = 32 [27-37] vs. 36 [25-42] %, P = .013 but no significant change was observed in the R-group: 26 [22-34] vs. 27 [24-33] %, p = .386.Conclusion: Recruitment maneuver improved PaO2/FiO2 ratio by ≥ 20 % in 50 % of patients ventilated in CPAP/PS mode.

  13. 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.

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

    Science.gov (United States)

    Adeleye, Adetayo; Nettel-Aguirre, Alberto; Buchhalter, Jeffrey; Kirk, Valerie

    2016-01-01

    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.

  15. Compliance with continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea among privately paying patients- a cross sectional study

    OpenAIRE

    Hussain, Syed Fayyaz; Irfan, Muhammad; Waheed, Zeeshan; Alam, Naveen; Mansoor, Saba; Islam, Muhammad

    2014-01-01

    Background To evaluate the compliance, benefits and side effects associated with continuous positive airway pressure (CPAP) therapy among Pakistani patients treated for obstructive sleep apnea (OSA) in private sector. Methods Patients diagnosed to have OSA based on overnight study who were recommended for CPAP therapy, between 1998 and 2003, were evaluated by telephonic survey and review of hospital notes. Compliance, benefits and side effects associated with CPAP therapy were assessed. Resul...

  16. The Role of Continuous Positive Airway Pressure Therapy in the Management of Respiratory Distress in Extremely Premature Infants

    OpenAIRE

    Sekar, Kris

    2006-01-01

    The use of mechanical ventilation for the treatment of respiratory distress syndrome (RDS) in low birth weight infants may cause barotrauma, volutrauma, and chronic lung disease. Different continuous positive airway pressure (CPAP) delivery systems exist, each with its own practical and clinical advantages and disadvantages. CPAP can be used as either a primary or an adjunctive respiratory support for RDS. Research demonstrates that CPAP decreases the incidence of respiratory failure after ex...

  17. Comparison of volume-controlled and pressure-controlled ventilation using a laryngeal mask airway during gynecological laparoscopy

    OpenAIRE

    Jeon, Woo Jae; Cho, Sang Yun; Bang, Mi Rang; Ko, So-Young

    2011-01-01

    Background Several publications have reported the successful, safe use of Laryngeal Mask Airway (LMA)-Classic devices in patients undergoing laparoscopic surgery. However, there have been no studies that have examined the application of volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV) using a LMA during gynecological laparoscopy. The aim of this study is to compare how the VCV and PCV modes and using a LMA affect the pulmonary mechanics, the gas exchange and the ca...

  18. Daytime sleepiness, cognitive performance and mood after continuous positive airway pressure for the sleep apnoea/hypopnoea syndrome.

    OpenAIRE

    Engleman, H. M.; Cheshire, K. E.; Deary, I.J.; Douglas, N.J.

    1993-01-01

    BACKGROUND--Patients with the sleep apnoea/hypopnoea syndrome often receive continuous positive airway pressure to improve their symptoms and daytime performance, yet objective evidence of the effect of this treatment on cognitive performance is lacking. METHODS--A prospective parallel group study was performed comparing the change in objective daytime sleepiness as assessed by multiple sleep latency, cognitive function, and mood in 21 patients (mean (SE) number of apnoeas and hypopnoeas/hour...

  19. 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

  20. A comparison of continuous and bi-level positive airway pressure non-invasive ventilation in patients with acute cardiogenic pulmonary oedema: a meta-analysis

    OpenAIRE

    Ho, Kwok M.; Wong, Karen

    2006-01-01

    Introduction We conducted the present study to investigate the potential beneficial and adverse effects of continuous positive airway pressure (CPAP) compared with bi-level positive airway pressure (BiPAP) noninvasive ventilation in patients with cardiogenic pulmonary oedema. Method We included randomized controlled studies comparing CPAP and BiPAP treatment in patients with cardiogenic pulmonary oedema from the Cochrane Controlled Trials Register (2005 issue 3), and EMBASE and MEDLINE databa...

  1. Influence of Chronic Sinusitis and Nasal Polyp on the Lower Airway of Subjects Without Lower Airway Diseases

    OpenAIRE

    Lee, Suh-Young; Yoon, Soon Ho; Song, Woo-Jung; Lee, So-Hee; Kang, Hye-Ryun; Kim, Sun-Sin; Cho, Sang-Heon

    2014-01-01

    Purpose Upper and lower respiratory tract pathologies are believed to be interrelated; however, the impact of upper airway inflammation on lung function in subjects without lung disease has not been evaluated. This study investigated the association of CT finding suggesting chronic sinusitis and lung function in healthy subjects without lung disease. Methods This was a retrospective study of prospectively collected data from 284 subjects who underwent a pulmonary function test, bronchial prov...

  2. Moderately high frequency ventilation with a conventional ventilator allows reduction of tidal volume without increasing mean airway pressure

    OpenAIRE

    Cordioli, Ricardo Luiz; Park, Marcelo; Costa, Eduardo Leite Vieira; Gomes, Susimeire; Brochard, Laurent; Amato, Marcelo Britto Passos; Azevedo, Luciano Cesar Pontes

    2014-01-01

    Background The aim of this study was to explore if positive-pressure ventilation delivered by a conventional ICU ventilator at a moderately high frequency (HFPPV) allows a safe reduction of tidal volume (V T) below 6 mL/kg in a porcine model of severe acute respiratory distress syndrome (ARDS) and at a lower mean airway pressure than high-frequency oscillatory ventilation (HFOV). Methods This is a prospective study. In eight pigs (median weight 34 [29,36] kg), ARDS was induced by pulmonary la...

  3. 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.

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

    International Nuclear Information System (INIS)

    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.

  5. 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 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 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

  6. 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.

  7. Impact Of Nasal Continuous Positive Airway Pressure On Excessive Daytime Sleepiness In Obstructive Sleep Apnea Patients

    Directory of Open Access Journals (Sweden)

    Geetha Kandasamy

    2013-01-01

    Full Text Available Purpose: To study the impact of nasal continuous positive airway pressure (nCPAP on excessive daytime sleepiness in obstructive sleep apnea patients (OSA. Method: Patient’s data were collected through direct patient interview and polysomnographic reports. Excessive daytime sleepiness (EDS was assessed by using Epworth Sleepiness Scale (ESS at baseline and after six months of nCPAP treatment. Results: This prospective study was conducted from August 2008 to June 2012. A total of 141patients were diagnosed as OSA based on Apnea Hypopnea Index. The study group (n=141 was further categorized based on AHI as Mild, Moderate and Severe. AHI 17.71% (31 had mild OSA (AHI 5-14.9, 33.14% (24 had moderate (AHI 15-29.9 Events/hourand 49.14% (86 were found to have severe OSA (AHI≥30. Evaluation of demographic data revealed that among the 141 patients, 121 were male (85.81% and 20 were female (14.48% and the mean age was 51.82±11.77 years. The mean ESS Score for mild OSA, moderate OSA, and severe obstructive sleep apnea groups were 8.13±1.78, 13.45±3.14, 15.48±5.22 respectively. The ESS score was significantly higher in severe obstructive sleep apnea patients as compared to mild and moderate OSA. ESS scores at baseline were 12.48±3.12 and after nCPAP treatment were 6.42±2.92. Significantly improved after 6 months of nCPAP treatment. Conclusion: Nasal CPAP reduces daytime sleepiness, resulting in an increased daytime activity. Subjective sleepiness was also (Excessive daytime sleepiness significantly improved after 6 months of nCPAP treatment.

  8. Mean airway pressure and response to inhaled nitric oxide in neonatal and pediatric patients.

    Science.gov (United States)

    Hoffman, George M; Nelin, Leif D

    2005-01-01

    Inhaled nitric oxide (iNO) can improve oxygenation and ventilation-perfusion (V/Q) matching by reduction of shunt (Qs/Qt) in patients with hypoxemic lung disease. Because the improvement in V/Q matching must occur by redistribution of pulmonary blood flow, and because high airway pressure (Paw) increases physiologic dead space (Vd/Vt), we hypothesized that high Paw may limit the improvement in V/Q matching during iNO treatment. iNO 0-50 ppm was administered during mechanical ventilation. Mechanical ventilator settings were at the discretion of the attending physician. Qs/Qt and Vd/Vt were derived from a tripartite lung model with correction for shunt-induced dead space. Data from 62 patients during 153 trials were analyzed for effects of Paw and iNO on Qs/Qt and Vd/Vt. Baseline Qs/Qt was slightly increased at Paw 16-23 cmH2O (p < 0.05), while Vd/Vt increased progressively with higher Paw (p < 0.002). Therapy with iNO significantly reduced Qs/Qt (p < 0.001) at all levels of mean Paw, reaching a maximum reduction at 16-23 cmH2O (p < 0.05), such that Qs/Qt during iNO treatment was similar at all levels of Paw. During iNO treatment, a reduction in Vd/Vt occurred only at Paw of 8-15 cmH2O (p < 0.05), and the positive relationship between Vd/Vt and Paw was maintained. These differential effects on Qs/Qt and Vd/Vt suggest that both high and low Paw may limit improvement in gas exchange with iNO. Analysis of gas exchange using this corrected tripartite lung model may help optimize ventilatory strategies during iNO therapy. PMID:16465603

  9. Application of continuous positive airway pressure in the delivery room: a multicenter randomized clinical trial

    Directory of Open Access Journals (Sweden)

    W.A. Goncalves-Ferri

    2014-03-01

    Full Text Available This study evaluated whether the use of continuous positive airway pressure (CPAP in the delivery room alters the need for mechanical ventilation and surfactant during the first 5 days of life and modifies the incidence of respiratory morbidity and mortality during the hospital stay. The study was a multicenter randomized clinical trial conducted in five public university hospitals in Brazil, from June 2008 to December 2009. Participants were 197 infants with birth weight of 1000-1500 g and without major birth defects. They were treated according to the guidelines of the American Academy of Pediatrics (APP. Infants not intubated or extubated less than 15 min after birth were randomized for two treatments, routine or CPAP, and were followed until hospital discharge. The routine (n=99 and CPAP (n=98 infants studied presented no statistically significant differences regarding birth characteristics, complications during the prenatal period, the need for mechanical ventilation during the first 5 days of life (19.2 vs 23.4%, P=0.50, use of surfactant (18.2 vs 17.3% P=0.92, or respiratory morbidity and mortality until discharge. The CPAP group required a greater number of doses of surfactant (1.5 vs 1.0, P=0.02. When CPAP was applied to the routine group, it was installed within a median time of 30 min. We found that CPAP applied less than 15 min after birth was not able to reduce the need for ventilator support and was associated with a higher number of doses of surfactant when compared to CPAP applied as clinically indicated within a median time of 30 min.

  10. 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

  11. Influence of pressure on Leidenfrost effect

    OpenAIRE

    Buchmüller, Ilja

    2014-01-01

    The Leidenfrost effect influences substantially the contact of a liquid droplet with a hot surface. Contact between the liquid and solid is crucial for cooling applications such as fire-fighting, hot-mill steel rolling, thermal power plants and microprocessor cooling. In automotive or aerospace internal combustion engines, the combustion chamber is pressurized prior to ignition. Despite various effects of elevated pressure, the combustion process needs to be controlled. The rea...

  12. 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

    OpenAIRE

    Nobuto Onda; Shintaro Chiba; Hiroto Moriwaki; Rika Sawai; Akira Yoshigoe; Subaru Watanabe; Yuji Ando; Ryo Uchida; Takeshi Miyawaki; Kota Wada

    2015-01-01

    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...

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

    International Nuclear Information System (INIS)

    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

  15. Influence of prone-position combined with message on the feeding intolerance of premature infants with nasal continuous positive airway pressure%俯卧位联合抚触对鼻塞持续气道正压通气早产儿喂养不耐受的影响

    Institute of Scientific and Technical Information of China (English)

    曹雪宏; 汪盈; 余海英; 项旦丹

    2015-01-01

    Objective To discuss prone-position combined with massage impacted on the feeding intolerance of premature infant with nasal continuous positive airway pressure. Methods The objects of study were the 134 premature infants with nasal continuous positive airway pressure ( NCPAP) in Neonatal Intensive Care Unit ( NICU ) the Second Affiliated Hospital of Wenzhou Medical University from January to December 2013. According to the single-blinded and random number table, they were divided into 4 groups, namely prone position group ( 33 cases ) , supine position group ( 34 cases ) , prone-position combined massage group (32 cases) and supine-position combined massage group (35 cases). All these 4 groups were given NCPAP and relevant nursing treatment; the feeding effects of 4 groups were compared. Results With regard to feeding intolerance concerning vomit, abdominal distension and gastric retention in 4 groups, prone-position combined massage group was lower than the other groups with statistical significance (P<0. 05). The time of NCPAP, days of hospitalization, length of nasogastric tube indwelling, time of regaining birth weight and time of reaching full enteral nutrition existed differences in 4 groups, in which infants of prone-position combined with message used least time with statistical significance (P <0. 05). Conclusions The prone-position combined with massage group attributes to the gastrointastinal tract function and feeding intolerance condition of premature infant and reduces mechanical ventilation time and length of hospitalization.%目的:探讨俯卧位联合抚触对鼻塞持续气道正压通气( NCPAP)的早产儿喂养不耐受的影响。方法选择2013年1—12月温州医科大学附属第二医院新生儿重症监护室( NICU)收治的早产儿134例,按单盲随机化分组对照原则,采用随机数字法分为4组进行观察:仰卧位组(33例)、俯卧位组(34例)、仰卧位联合抚触组(32例)、俯卧位联合抚触组(35

  16. 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

  17. 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.

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

    International Nuclear Information System (INIS)

    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. (author)

  19. 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)

  20. Dose the oropharyngeal fat tissue influence the oropharyngeal airway in snorers? Dynamic CT study

    International Nuclear Information System (INIS)

    The aim of this study was to determine if snorers have a narrower oropharyngeal airway area because of fat infiltration, and an elevated body mass index. Ten control subjects and 19 patients that snored were evaluated. We obtained 2-mm-thick axial CT scan images every 0.6 seconds during expiration and inspiration at the same level of the oropharynx. We selected the largest and the smallest oropharyngeal airway areas and found the differences. From the slice that had the smallest oropharyngeal airway area, the thickness of the parapharyngeal and subcutaneous fat was measured. The measurements from the left and right side were added together and single values for parapharyngeal and subcutaneous fat tissue thickness were then found. The conventional measure of body mass index was significantly higher in the snorers (ρ 0.05). We concluded that the oropharyngeal fat deposition in snorers is not an important factor, and it does not predispose a person to the upper airway narrowing

  1. Effect of continuous positive airway pressure ventilation on prethrombotic state in patients with obstructive sleep apnea-hypopnea syndrome

    International Nuclear Information System (INIS)

    To investigate the prethrombotic state (PTS) in patients with obstructive sleep apnea syndrome (OS-AS) and the effect of continuous positive airway pressure ventilation (CPAP) on their PTS, the blood samples of 49 patients with OSAS were taken before treatment and on day 30 after treatment respectively. The platelet aggregation ( PAG), P-selections, endothdlin-1 (ET-1) and plasma vom willebrand factor (vWF) in 49 patients and 42 health controls were detected by radioimmunoassay and enzyme-immunoassay. The results showed that the PAG, P-selections, ET-1 and vWF in patients with OSAS before treatment were significantly higher than those after treatment and in control group (P0.05). The results indicate that there were PTS in most patients with OSAS before treatment. The activity of platelet could be corrected, and the function of endotheliocyte could be repaired after CPAP treatment. It had certain effect in lightening the clinical symptoms. (authors)

  2. Experience of nasal continuous positive airway pressure (cpap) by infant flow driver in a neonatal unit of a developing country

    International Nuclear Information System (INIS)

    Objective: To study the safety and efficacy of nasal continuous positive airways pressure by infant flow drivers in neonates admitted with respiratory problems. Study Design: Quasi-experimental study. Place and Duration of Study: This study was conducted at CMH Lahore from April 2012 to March 2013. Subjects and Methods: All infants who were treated with nasal continuous positive airway pressure (nCPAP) for various indications at neonatal intensive care unit (NICU) of CMH Lahore were evaluated for gestational, age, weight, gender, indications and duration on nCPAP, pre-defined outcomes, complications and length of hospital stay. Efficacy was defined as the ability to manage an infant on nCPAP alone thus avoiding the need for mechanical ventilation. Results: During the study period, 343 neonates were admitted in NICU, forty five neonates were placed on nCPAP. Mean gestational age was 33.85+ 3 weeks. Mean weight was 2043 + 770 grams. Main indications for applying nCPAP were respiratory distress syndrome (48.9%) and neonatal pneumonia (17.8%). Most common complication was abdominal distension (6.7%). Out of 45 infants placed on nCPAP, 32 (71.1%) were managed on nCPAP alone while 13 (28.9%) needed mechanical ventilation after nCPAP failure. Conclusion: Nasal CPAP by an infant flow driver is a useful method to manage respiratory distress in neonates. It reduces the need for mechanical ventilation and can be used as first line respiratory support before mechanical ventilation. (author)

  3. A Respiratory Airway-Inspired Low-Pressure, Self-Regulating Valve for Drip Irrigation

    Science.gov (United States)

    Wang, Ruo-Qian; Winter, Amos G.; GEAR Lab Team

    2015-11-01

    One of the most significant barriers to achieving large-scale dissemination of drip irrigation is the cost of the pump and power system. An effective means of reducing power consumption is by reducing pumping pressure. The principle source of pressure drop in a drip system is the high flow resistance in the self-regulating flow resistors installed at the outlets of the pips, which evenly distribute water over a field. Traditional architectures require a minimum pressure of ~1 bar to maintain a constant flow rate; our aim is to reduce this pressure by 90% and correspondingly lower pumping power to facilitate the creation of low-cost, off-grid drip irrigation systems. This study presents a new Starling resistor architecture that enables the adjustment of flow rate with a fixed minimum pressure demand of ~0.1 bar. A Starling resistor is a flexible tube subjected to a transmural pressure, which collapses the tube to restrict flow. Our design uses a single pressure source to drive flow through the flexible tube and apply a transmural pressure. Flow into the flexible tube is restricted with a needle valve, to increase the transmural pressure. Using this device, a series of experiments were conducted with different flexible tube diameters, lengths and wall thickness. We found that the resistance of the needle valve changes flow rate but not the minimum transmural pressure required to collapse the tube. A lumped-parameter model was developed to capture the relationships between valve openings, pressure, and flow rates.

  4. The effect of airway pressure and oscillation amplitude on ventilation in pre-term infants.

    Science.gov (United States)

    Miedema, Martijn; de Jongh, Frans H; Frerichs, Inez; van Veenendaal, Mariette B; van Kaam, Anton H

    2012-08-01

    We determined the effect of lung recruitment and oscillation amplitude on regional oscillation volume and functional residual capacity (FRC) in high-frequency oscillatory ventilation (HFOV) used in pre-term infants with respiratory distress syndrome (RDS). Changes in lung volume, oscillation volume and carbon dioxide levels were recorded in 10 infants during a stepwise recruitment procedure, and an increase in pressure amplitude of 5 cmH(2)O was measured using electrical impedance tomography and transcutaneous monitoring. The pressures at maximal respiratory system compliance, maximal oscillation volume and minimal carbon dioxide levels were determined. Impedance data were analysed for the chest cross-section and predefined regions of interest. Despite the fixed pressure amplitude, the oscillation volume changed during the incremental pressure steps following a parabolic pattern, with an inverse relationship to the carbon dioxide pressures. The pressures corresponding with maximal compliance, maximal oscillation volume and minimal carbon dioxide were similar and highly correlated. Regional analysis showed similar findings. The increase in pressure amplitude resulted in increased oscillation volumes and decreased carbon dioxide levels, while FRC remained unchanged. In HFV pre-term infants with RDS, oscillation volumes are closely related to the position of ventilation in the pressure-volume envelope and the applied pressure amplitude. Changes in pressure amplitude do not seem to affect FRC. PMID:22362852

  5. Application of positive airway pressure in restoring pulmonary function and thoracic mobility in the postoperative period of bariatric surgery: a randomized clinical trial

    OpenAIRE

    Patrícia Brigatto; Carbinatto, Jéssica C.; Costa, Carolina M.; Montebelo, Maria I. L.; Irineu Rasera-Júnior; Pazzianotto-Forti, Eli M.

    2014-01-01

    Objective: To evaluate whether the application of bilevel positive airway pressure in the postoperative period of bariatric surgery might be more effective in restoring lung volume and capacity and thoracic mobility than the separate application of expiratory and inspiratory positive pressure. Method: Sixty morbidly obese adult subjects who were hospitalized for bariatric surgery and met the predefined inclusion criteria were evaluated. The pulmonary function and thoracic mobility were preope...

  6. Notwendigkeit einer Druckveränderung bei Patienten mit CPAP (Continuous Positive Airway Pressure)-Therapie 2 - 3 Monate nach der Ersteinstellung

    OpenAIRE

    Hofmann, Markus

    2007-01-01

    Study objectives: To investigate the need for pressure change in a larger group of patients with sleep disordered breathing (SDB) several weeks after initial CPAP (continuous positive airway pressure)/Bilevel-CPAP and auto-CPAP titration. Design: Prospective cohort study of consecutive patients with sleep disordered breathing and CPAP/Bilevel-CPAP/auto-CPAP therapy. Setting: Sleep laboratory in a regional hospital. Patients: 905 patients (740 m, 165 f) with SDB confirmed by polysomno...

  7. 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

  8. 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...... 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 recently reported an association between abnormal bacterial colonization with M. catarrhalis, S. pneumoniae, H. influenzae of the upper airways of neonates and later development of asthma. This led to the hypothesis that the interaction between genetics and this microbiome in very early life...

  9. Mucin glycosylation and sulphation in airway epithelial cells is not influenced by cystic fibrosis transmembrane conductance regulator expression.

    Science.gov (United States)

    Leir, Shih-Hsing; Parry, Simon; Palmai-Pallag, Timea; Evans, Joanne; Morris, Howard R; Dell, Anne; Harris, Ann

    2005-05-01

    Abnormalities in mucus properties and clearance make a major contribution to the pathology of cystic fibrosis (CF). Our aim was to test the hypothesis that the defects in CF mucus are a direct result of mutations in the CF transmembrane conductance regulator (CFTR) protein. We evaluated a single mucin molecule MUC1F/5ACTR that carries tandem repeat sequence from MUC5AC, a major secreted airway mucin, in a MUC1 mucin vector. To establish whether the presence of mutant or normal CFTR directly influences the O-glycosylation and sulphation of mucins in airway epithelial cells, we used the CFT1-LC3 (DeltaF508 CFTR mutant) and CFT1-LCFSN (wild-type CFTR corrected) human airway epithelial cell lines. MUC1F/5ACTR mucin was immunoprecipitated, centricon purified, and O-glycosylation was evaluated by Matrix-assisted laser desorption ionization and electrospray tandem mass spectrometry to determine the composition of different carbohydrate structures. Mass spectrometry data showed the same O-glycans in both CFTR mutant and wild-type CFTR corrected cells. Metabolic labeling assays were performed to evaluate gross glycosylation and sulphation of the mucins and showed no significant difference in mucin synthesized in six independent clones of these cell lines. Our results show that the absence of functional CFTR protein causes neither an abnormality in mucin O-glycosylation nor an increase in mucin sulphation. PMID:15677769

  10. 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.

  11. 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.

  12. 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.

  13. Sex Steroids Influence Brain-Derived Neurotropic Factor Secretion From Human Airway Smooth Muscle Cells.

    Science.gov (United States)

    Wang, Sheng-Yu; Freeman, Michelle R; Sathish, Venkatachalem; Thompson, Michael A; Pabelick, Christina M; Prakash, Y S

    2016-07-01

    Brain derived neurotropic factor (BDNF) is emerging as an important player in airway inflammation, remodeling, and hyperreactivity. Separately, there is increasing evidence that sex hormones contribute to pathophysiology in the lung. BDNF and sex steroid signaling are thought to be intricately linked in the brain. There is currently little information on BDNF and sex steroid interactions in the airway but is relevant to understanding growth factor signaling in the context of asthma in men versus women. In this study, we assessed the effect of sex steroids on BDNF expression and secretion in human airway smooth muscle (ASM). Human ASM was treated with estrogen (E2 ) or testosterone (T, 10 nM each) and intracellular BDNF and secreted BDNF measured. E2 and T significantly reduced secretion of BDNF; effects prevented by estrogen and androgen receptor inhibitor, ICI 182,780 (1 μM), and flutamide (10 μM), respectively. Interestingly, no significant changes were observed in intracellular BDNF mRNA or protein expression. High affinity BDNF receptor, TrkB, was not altered by E2 or T. E2 (but not T) significantly increased intracellular cyclic AMP levels. Notably, Epac1 and Epac2 expression were significantly reduced by E2 and T. Furthermore, SNARE complex protein SNAP25 was decreased. Overall, these novel data suggest that physiologically relevant concentrations of E2 or T inhibit BDNF secretion in human ASM, suggesting a potential interaction of sex steroids with BDNF in the airway that is different from brain. The relevance of sex steroid-BDNF interactions may lie in their overall contribution to airway diseases such as asthma. J. Cell. Physiol. 231: 1586-1592, 2016. © 2015 Wiley Periodicals, Inc. PMID:26566264

  14. 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

  15. Methods of airway resistance assessment.

    Science.gov (United States)

    Urbankowski, Tomasz; Przybyłowski, Tadeusz

    2016-01-01

    Airway resistance is the ratio of driving pressure to the rate of the airflow in the airways. The most frequent methods used to measure airway resistance are whole-body plethysmography, the interrupter technique and the forced oscillation technique. All these methods allow to measure resistance during respiration at the level close to tidal volume, they do not require forced breathing manoeuvres or deep breathing during measurement. The most popular method for measuring airway resistance is whole-body plethysmography. The results of plethysmography include among others the following parameters: airway resistance (Raw), airway conductance (Gaw), specific airway resistance (sRaw) and specific airway conductance (sGaw). The interrupter technique is based on the assumption that at the moment of airway occlusion, air pressure in the mouth is equal to the alveolar pressure . In the forced oscillation technique (FOT), airway resistance is calculated basing on the changes in pressure and flow caused by air vibration. The methods for measurement of airway resistance that are described in the present paper seem to be a useful alternative to the most common lung function test - spirometry. The target group in which these methods may be widely used are particularly the patients who are unable to perform spirometry. PMID:27238174

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

    Science.gov (United States)

    Fatureto-Borges, Fernanda; Lorenzi-Filho, Geraldo; Drager, Luciano F

    2016-01-01

    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), non-ideal 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. PMID:27051313

  17. Significance of upper airway influence among patients of vocal cord dysfunction for its diagnosis: Role of impulse oscillometry

    Directory of Open Access Journals (Sweden)

    Hira H

    2009-01-01

    Full Text Available Background: To identify the patients of bronchial asthma (suspected or proven, not responding to optimal therapy, for the presence of vocal cord dysfunction (VCD and to compare the diagnostic ability of flow volume (FV loop and impulse oscillometry (IOS. Materials and Methods: Fifty one patients of suspected/proven bronchial asthma not responding to optimal therapy were included for the study. Each patient was subjected to both FV loop and IOS studies. Direct visualization of the vocal cords with flexible fiberoptic bronchoscope for the presence of inspiratory vocal cord adduction during quiet respiration, with speech, and while performing provocative maneuvers was carried out. All patients were subjected to simple pulmonary function tests and recording of FV loop. IOS was performed on each patient to look for the site of obstruction and upper airway influence. The observations of both FV loop and IO studies were compared. Results: Among 51 patients participated, 12 (23.53% had bronchoscopical evidence of VCD and were labeled as VCD-positive group and rest 39 were designated VCD negative. No statistically significant difference in pulmonary function test (prereversibility results between the VCD-positive and VCD-negative patients was found. Reversible airway obstruction was observed in 75% of the patients of VCD-positive group and 67.65% of the patients in the VCD-negative group. Only one patient in the VCD-positive and none in VCD-negative group had inspiratory limb flattening of FV loop. Upper airway influence was evident by IOS in 58.3% of patients in the VCD-positive group and in 15.4% of patients in the VCD-negative group. This difference was statistically significant (P < 0.005. Conclusion: VCD was a common finding in patients with symptoms suggestive of asthma and frequently coexists with asthma. IOS was found to be a useful screening test for VCD and was more sensitive than FV loop.

  18. Continuous positive airway pressure therapy is associated with improvement in overactive bladder symptoms in women with obstructive sleep apnea syndrome

    Science.gov (United States)

    Ipekci, Tumay; Cetintas, Gulgun; Celik, Orcun; Sarac, Sema; Tunckiran, Ahmet; Ilbey, Yusuf Ozlem

    2016-01-01

    Introduction To evaluate the impact of continuous positive airway pressure (CPAP) therapy on overactive bladder (OAB) symptoms in women with obstructive sleep apnea syndrome (OSAS). Material and methods One-hundred and fifty women underwent an overnight polysomnography study between May 2014 and September 2014. Their voiding symptoms were evaluated using the OAB symptom score (OABSS) and International Consultation on Incontinence Questionnaire Short-Form at OSAS diagnosis and approximately 3-months after CPAP therapy. OSAS severity was assessed according to the apnea-hypopnea-index. Results We evaluated 140 women and 111 of them (79.3%) reported symptoms consistent with OAB. There were no statistically significant differences between OSAS severity with a prevalence of OAB (p = 0.92). The prevalence of urinary incontinence (UI) was 35.7% (n = 50) and 39.6% (n = 44) in all patients and patients with OAB, respectively. There were no statistically significant differences between UI with OAB (p = 0.58). Baseline OABSS is comparable between OSAS severity (p = 0.143). After 3-months CPAP therapy, OABSS and ICIQ-SF sum scores were significantly decreased in patients with severe and moderate OSAS (p <0.01), however, change of OABSS sum score was insignificant in patients with mild OSAS (p = 0.44). Conclusions CPAP therapy improves the OAB, OABSS and ICIQ-SF scores in women with severe and moderate OSAS. OSAS-induced OAB may be alleviated following CPAP therapy. PMID:27123331

  19. 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.

  20. Effects of 12 Months Continuous Positive Airway Pressure on Sympathetic Activity Related Brainstem Function and Structure in Obstructive Sleep Apnea

    Science.gov (United States)

    Henderson, Luke A.; Fatouleh, Rania H.; Lundblad, Linda C.; McKenzie, David K.; Macefield, Vaughan G.

    2016-01-01

    Muscle sympathetic nerve activity (MSNA) is greatly elevated in patients with obstructive sleep apnea (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 OSA subjects before and after 6 and 12 months of continuous positive airway pressure (CPAP) treatment. We found that following 6 and 12 months of CPAP treatment, resting MSNA levels were significantly reduced in individuals with OSA. Furthermore, this MSNA reduction was associated with restoration of MSNA-related brainstem 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 MSNA likely due to its effects on restoring brainstem structure and function. PMID:27013952

  1. 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; Greisen, Gorm

    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...... expressed as the arterial/alveolar oxygen tension ratio (a/A pO2 ratio) on postnatal day 28. METHODS: Preterm infants (birth weight <1,500 g and gestational age, GA >26 + 0 weeks) stable on nCPAP between postnatal days 4 and 7 were randomized to nCPAP or low-flow O2 by nasal cannula (<0.2 liters/min). Study...... criteria defined how to wean/restart respiratory support or change from low-flow O2 to nCPAP and vice versa. Transcutaneous monitoring was used for the assessment of the a/A pO2 ratio on day 28 using a head box for all infants for accurate measurement and to eliminate possible effects from nCPAP or low...

  2. 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.

  3. 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.

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

    OpenAIRE

    Lovya George; Sunil K Jain

    2015-01-01

    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 co...

  5. Influence of short distance transportation on tracheal bacterial content and lower airway cytology in horses.

    Science.gov (United States)

    Allano, Marion; Labrecque, Olivia; Rodriguez Batista, Edisleidy; Beauchamp, Guy; Bédard, Christian; Lavoie, Jean-Pierre; Leclere, Mathilde

    2016-08-01

    The aim of this study was to determine the effects of short distance transportation on airway mucus, cytology and bacterial culture to identify potential biases in the diagnosis of airway diseases in referral centres. Eight healthy adult horses were studied using a prospective cross-over design. Mucus scores, tracheal wash (cytology, bacterial culture) and bronchoalveolar lavage fluid (BALF; cytology) were obtained while stabled and following 2.5 h transportation (with and without hay). Neutrophil counts, percentages and BALF neutrophilia frequency increased following transport without hay (P  0.05). BALF neutrophilia could develop solely as a result of transportation or due to interactions between repeated transports, ambient temperature, head position or other environmental factors. PMID:27387726

  6. Early versus delayed initiation of nasal continuous positive airway pressure for treatment of respiratory distress syndrome in premature newborns: A randomized clinical trial

    OpenAIRE

    Zohreh Badiee; Fatemeh Naseri; Alireza Sadeghnia

    2013-01-01

    Background: This prospective study was performed to identify whether the early use of nasal continuous positive airway pressure (n CPAP) would reduce the rate of endotracheal intubation, mechanical ventilation and surfactant administration. Materials and Methods: This study was conducted from June 2009 to September 2010 in the Shahid Beheshti University Hospital, Isfahan-Iran. A total of 72 preterm infants with 25-30 weeks gestation who needed respiratory support at 5 min after birth enter...

  7. Adolescents with Obstructive Sleep Apnea Adhere Poorly to Positive Airway Pressure (PAP), but PAP Users Show Improved Attention and School Performance

    OpenAIRE

    Beebe, Dean W; Byars, Kelly C.

    2011-01-01

    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 determi...

  8. Application of positive airway pressure in restoring pulmonary function and thoracic mobility in the postoperative period of bariatric surgery: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Patrícia Brigatto

    2014-12-01

    Full Text Available Objective: To evaluate whether the application of bilevel positive airway pressure in the postoperative period of bariatric surgery might be more effective in restoring lung volume and capacity and thoracic mobility than the separate application of expiratory and inspiratory positive pressure. Method: Sixty morbidly obese adult subjects who were hospitalized for bariatric surgery and met the predefined inclusion criteria were evaluated. The pulmonary function and thoracic mobility were preoperatively assessed by spirometry and cirtometry and reevaluated on the 1st postoperative day. After preoperative evaluation, the subjects were randomized and allocated into groups: EPAP Group (n=20, IPPB Group (n=20 and BIPAP Group (n=20, then received the corresponding intervention: positive expiratory pressure (EPAP, inspiratory positive pressure breathing (IPPB or bilevel inspiratory positive airway pressure (BIPAP, in 6 sets of 15 breaths or 30 minutes twice a day in the immediate postoperative period and on the 1st postoperative day, in addition to conventional physical therapy. Results: There was a significant postoperative reduction in spirometric variables (p0.05. Thoracic mobility was preserved only in group BIPAP (p>0.05, but no significant difference was found in the comparison among groups (p>0.05. Conclusion: The application of positive pressure does not seem to be effective in restoring lung function after bariatric surgery, but the use of bilevel positive pressure can preserve thoracic mobility, although this technique was not superior to the other techniques.

  9. Neurturin influences inflammatory responses and airway remodeling in different mouse asthma models.

    Science.gov (United States)

    Mauffray, Marion; Domingues, Olivia; Hentges, François; Zimmer, Jacques; Hanau, Daniel; Michel, Tatiana

    2015-02-15

    Neurturin (NTN) was previously described for its neuronal activities, but recently, we have shown that this factor is also involved in asthma physiopathology. However, the underlying mechanisms of NTN are unclear. The aim of this study was to investigate NTN involvement in acute bronchial Th2 responses, to analyze its interaction with airway structural cells, and to study its implication in remodeling during acute and chronic bronchial inflammation in C57BL/6 mice. We analyzed the features of allergic airway inflammation in wild-type and NTN(-/-) mice after sensitization with two different allergens, OVA and house dust mite. We showed that NTN(-/-) dendritic cells and T cells had a stronger tendency to activate the Th2 pathway in vitro than similar wild-type cells. Furthermore, NTN(-/-) mice had significantly increased markers of airway remodeling like collagen deposition. NTN(-/-) lung tissues showed higher levels of neutrophils, cytokine-induced neutrophil chemoattractant, matrix metalloproteinase 9, TNF-α, and IL-6. Finally, NTN had the capacity to decrease IL-6 and TNF-α production by immune and epithelial cells, showing a direct anti-inflammatory activity on these cells. Our findings support the hypothesis that NTN could modulate the allergic inflammation in different mouse asthma models. PMID:25595789

  10. Influence of bronchoalveolar lavage volume on cytological profiles and subsequent diagnosis of inflammatory airway disease in horses.

    Science.gov (United States)

    Orard, Marie; Depecker, Marianne; Hue, Erika; Pitel, Pierre-Hugues; Couroucé-Malblanc, Anne; Richard, Eric A

    2016-01-01

    The aim of the study was to determine whether instillation of either 250 mL or 500 mL of saline for bronchoalveolar lavage (BAL) would influence cytological confirmation of inflammatory airway disease (IAD). Thirty client-owned Standardbred racehorses were sampled via endoscopy with 250 mL of saline in one lung and 500 mL in the contralateral lung. The procedure was repeated 72 h later, reversing the volume per lung. The proportions of BAL fluid (BALF) recovered were significantly higher and neutrophil percentages significantly lower with the larger volume. A poor agreement was found between methodologies in terms of final diagnosis, when based on proportions of neutrophils (>10% from at least one lung). Within the recommended range (250–500 mL), the instilled volume significantly influenced cytological profiles. Establishing specific BALF reference values is warranted. PMID:27152385

  11. 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

  12. Issues of critical airway management (Which anesthesia; which surgical airway?

    Directory of Open Access Journals (Sweden)

    Fabrizio Giuseppe Bonanno

    2012-01-01

    Full Text Available Which anesthesia for patients with critical airway? Safe and effective analgesia and anesthesia in critical airway is a skilled task especially after severe maxillofacial injury combined with head injury and hemorrhagic shock. If on one side sedation is wanted, on the other hand it may worsen the airway and hemodynamic situation to a point where hypoventilation and decrease of blood pressure, common side-effect of many opioids, may prejudice the patient′s level of consciousness and hemodynamic compensation, compounding an already critical situation. What to do when endotracheal intubation fails and blood is trickling down the airways in an unconscious patient or when a conscious patient has to sit up to breathe? Which surgical airway in critical airway? Comparative studies among the various methods of emergency surgical airway would be unethical; furthermore, operator′s training and experience is relevant for indications and performance.

  13. Issues of critical airway management (Which anesthesia; which surgical airway?).

    Science.gov (United States)

    Bonanno, Fabrizio Giuseppe

    2012-10-01

    Which anesthesia for patients with critical airway? Safe and effective analgesia and anesthesia in critical airway is a skilled task especially after severe maxillofacial injury combined with head injury and hemorrhagic shock. If on one side sedation is wanted, on the other hand it may worsen the airway and hemodynamic situation to a point where hypoventilation and decrease of blood pressure, common side-effect of many opioids, may prejudice the patient's level of consciousness and hemodynamic compensation, compounding an already critical situation. What to do when endotracheal intubation fails and blood is trickling down the airways in an unconscious patient or when a conscious patient has to sit up to breathe? Which surgical airway in critical airway? Comparative studies among the various methods of emergency surgical airway would be unethical; furthermore, operator's training and experience is relevant for indications and performance. PMID:23248494

  14. 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.

  15. Effect of telemetric monitoring in the first 30 days of continuous positive airway pressure adaptation for obstructive sleep apnoea syndrome - a controlled pilot study.

    Science.gov (United States)

    Frasnelli, Matthias; Baty, Florent; Niedermann, Jolanda; Brutsche, Martin H; Schoch, Otto D

    2016-06-01

    Obstructive sleep apnoea syndrome (OSAS) is characterised by repetitive collapse of the upper airway during sleep. Continuous positive airway pressure (CPAP) applied via a mask is the standard treatment for OSAS. CPAP adherence is crucial in therapy to prevent the deleterious consequences of OSAS. We hypothesised that a combination of supervision by telemetry together with targeted telephone support in the first month of CPAP would increase CPAP adherence and treatment success. A total of 113 OSAS patients followed by telemetry-triggered interventions used the device for 5.3 h/night on 28/30 nights, significantly more than the 110 OSAS patients in the control group with 4.6 h/night and 27/30 nights. Telemetry-triggered interventions have a significant impact on adherence rate in early CPAP treatment. These results can be reached with an acceptable additional effort. PMID:26253747

  16. Recent advances in airway management in children

    OpenAIRE

    Veyckemans, Francis

    2009-01-01

    Recent anatomic findings, technological progress, and both in vitro and in vivo studies of the pressure generated in the cuff of endotracheal tubes and supraglottic airways should lead to modification of the way we control the pediatric upper airway.

  17. 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.

  18. Comparison of 3 titration methods of positive airway pressure for obstructive sleep apnea syndrome: a random, single-blind and self-control clinical study

    Directory of Open Access Journals (Sweden)

    Yan LI

    2013-05-01

    Full Text Available Objective  To evaluate the efficacy and safety of polysomnography-manual continuous positive airway pressure titration (PSG-CPAP, polysomnography-automatic positive airway pressure titration (PSG-APAP, or automatic positive airway pressure titration (APAP in patients with moderate or severe simple obstructive sleep apnea syndrome (OSAS. Methods  Twenty patients with moderate or severe OSAS sequentially underwent PSG-CPAP, PSG-APAP and APAP titration 3 days apart, and then 3 primary efficacy indicators (titration pressure, remaining respiratory event and state of sleep, and safety indicators (compression injury of face skin, the subjective evaluation on degree of comfort or any complaint during titration were compared. Results  The results of efficacy indicators revealed that all PSG-APAP, APAP and PSG-CPAP were effective. Compared with the optimal pressure of PSG-CPAP titration, PSG-APAP and APAP pressures were 3.05 and 2.55cmH2O higher, respectively, in 90% of occasion (P0.05. There was no statistically significant difference between the optimal pressure of PSG-CPAP and the mean pressures of PSG-APAP and APAP (P>0.05. There was no statistically significant difference between the 3 titration methods on residue apnea/hypopnea index (AHI, P>0.05. The oxygen desaturation index (ODI decreased significantly after titration treatment (P0.05. Both PSG-CPAP and PSG-APAP titrations showed the same effects in improving ODI. Compared with basic PSG, no obvious improvement was found in sleep efficiency (SE after PSG-CPAP and PSG-APAP titration (P>0.05, however, the arousal index (ArI decreased obviously (P0.05. The results of safety indicators showed that no face skin compression injury or severe adverse event related to the titration was found in all the patients during the study. The main complaints of the patients were sleep disturbance, dryness of eyes or mouth, headache, breath holding and abdominal distention. Conclusion  Both PSG-APAP and

  19. Issues of critical airway management (Which anesthesia; which surgical airway?)

    OpenAIRE

    Fabrizio Giuseppe Bonanno

    2012-01-01

    Which anesthesia for patients with critical airway? Safe and effective analgesia and anesthesia in critical airway is a skilled task especially after severe maxillofacial injury combined with head injury and hemorrhagic shock. If on one side sedation is wanted, on the other hand it may worsen the airway and hemodynamic situation to a point where hypoventilation and decrease of blood pressure, common side-effect of many opioids, may prejudice the patient′s level of consciousness and hemodynami...

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

    OpenAIRE

    Xiao Hui; Tao Hongsheng; Qiao Hongjun; Mu Jingfu; Dong Sha

    2015-01-01

    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 obser...

  1. DIFFICULT AIRWAY IN THYROID SURGERY

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    Cuello-Azcárate JJ

    2011-12-01

    Full Text Available Background: Thyroid surgery has been considered as a risk factor for the management of difficult airway.Method: We review the relevant literature related to the difficult airway and thyroid surgery.Comments: Endothoracic goiter, deformity of the airway, compression of the airway and thyroid cancer do not appear to have an influence on the difficulty for intubation.Classical parameters have a better predictive value: mouth opening less than 35 mm, Mallampati II-IV, short neck, neck movility less than 80 degrees, thyromental distance less than 60 mm, retrognathia, Cormack index III-IV, macroglossia, inability to protude the teeth and body mass index (BMI greater than 35 Kg/m2.Conclusions: According to the literature, thyroid disease does not increase the risk for a difficult airway (ventilation / intubation.The risk of an unexpected difficult airway (false negative cannot be eliminated.All patients must undergo an assessment of the airway

  2. Evaluation of an oral appliance in patients with mild to moderate obstructive sleep apnea syndrome intolerant to continuous positive airway pressure use: Preliminary results.

    Science.gov (United States)

    Cantore, S; Ballini, A; Farronato, D; Malcangi, G; Dipalma, G; Assandri, F; Garagiola, U; Inchingolo, F; De Vito, D; Cirulli, N

    2016-06-01

    Obstructive sleep apnea syndrome (OSAS) is a phenomenon of repeated, episodic reduction, or cessation of airflow (hypopnea/apnea) as a result of upper airways obstruction. First-line treatment in younger children is adenotonsillectomy, although other available treatment options in middle-aged adults include continuous positive airways pressure (CPAP) and airway adjuncts. Oral appliances (OA) are a viable treatment alternative in patients with OSAS.The objective of this study was to assess, in a 1-year follow-up study, an OA in OSAS patients. The participants were subjected to polysomnographic examination with a validated device (MicroMESAM). Eight participants were fitted with a Thornton Adjustable Positioner (TAP). The participants were asked to wear the test appliance for 7 nights, and in case of compliance, for 6 months. The selected patients record their usage of the appliance and any adverse effects in a treatment journal. The research focused on the following outcomes: sleep apnea (i.e. reduction in the apnea/hypopnea index) and the effect of oral appliances on daytime function.In conclusion, the results suggest that OA have a definite role in the treatment of snoring and sleep apnea. PMID:26684627

  3. 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...... 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]......Process monitoring of microinjection moulding (mu IM) is of crucial importance when analysing the effect of different parameter settings on the process and then in assessing its quality. Quality factors related to cavity pressure can provide valuable information about the process dynamics and also...

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

    International Nuclear Information System (INIS)

    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 cm3 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

  5. 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.

  6. Influence of genetic variance on sodium sensitivity of blood pressure.

    Science.gov (United States)

    Luft, F C; Miller, J Z; Weinberger, M H; Grim, C E; Daugherty, S A; Christian, J C

    1987-02-01

    To examine the effect of genetic variance on blood pressure, sodium homeostasis, and its regulatory determinants, we studied 37 pairs of monozygotic twins and 18 pairs of dizygotic twins under conditions of volume expansion and contraction. We found that, in addition to blood pressure and body size, sodium excretion in response to provocative maneuvers, glomerular filtration rate, the renin-angiotensin system, and the sympathetic nervous system are influenced by genetic variance. To elucidate the interaction of genetic factors and an environmental influence, namely, salt intake, we restricted dietary sodium in 44 families of twin children. In addition to a modest decrease in blood pressure, we found heterogeneous responses in blood pressure indicative of sodium sensitivity and resistance which were normally distributed. Strong parent-offspring resemblances were found in baseline blood pressures which persisted when adjustments were made for age and weight. Further, mother-offspring resemblances were observed in the change in blood pressure with sodium restriction. We conclude that the control of sodium homeostasis is heritable and that the change in blood pressure with sodium restriction is familial as well. These data speak to the interaction between the genetic susceptibility to hypertension and environmental influences which may result in its expression. PMID:3553721

  7. 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.

  8. 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.

  9. Effects of naloxone on upper airway collapsibility in normal sleeping subjects.

    OpenAIRE

    Meurice, J.C.; Marc, I; Sériès, F.

    1996-01-01

    BACKGROUND: To evaluate the possible influence of endorphin release on upper airway collapsibility the effects of naloxone, an opiate receptor antagonist, were measured. METHODS: The effects of naloxone on upper airway collapsibility were studied in five normal sleeping men in a pilot study. During a sleep fragmentation night the subjects received either naloxone or a volume matched saline placebo in a double blind crossover design. Critical pressure (Pcrit) was measured during a morning nap ...

  10. 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.

  11. 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. PMID:10894453

  12. The Influence of Peer Group Pressure Upon Adolescents' Learning.

    Science.gov (United States)

    Dilanian, Seta M.

    An adolescent's learning patterns are developed throughout the student's socialization process, suggesting that peer pressure may influence learning. Female college students (N=15) aged 19-21 participated in a pencil-maze learning task performed while blindfolded. The task was presented in three categories of stimuli conditions: (1) normal…

  13. 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.

  14. Meta-analysis of randomised controlled trials of oral mandibular advancement devices and continuous positive airway pressure for obstructive sleep apnoea-hypopnoea.

    Science.gov (United States)

    Sharples, Linda D; Clutterbuck-James, Abigail L; Glover, Matthew J; Bennett, Maxine S; Chadwick, Rebecca; Pittman, Marcus A; Quinnell, Timothy G

    2016-06-01

    Obstructive sleep apnoea-hypopnoea (OSAH) causes excessive daytime sleepiness, impairs quality-of-life, and increases cardiovascular disease and road traffic accident risks. Continuous positive airway pressure (CPAP) treatment and mandibular advancement devices (MAD) have been shown to be effective in individual trials but their effectiveness particularly relative to disease severity is unclear. A MEDLINE, Embase and Science Citation Index search updating two systematic reviews to August 2013 identified 77 RCTs in adult OSAH patients comparing: MAD with conservative management (CM); MAD with CPAP; or CPAP with CM. Overall MAD and CPAP significantly improved apnoea-hypopnoea index (AHI) (MAD -9.3/hr (p hr (p effective in the treatment of OSAH. Although CPAP has a greater treatment effect, MAD is an appropriate treatment for patients who are intolerant of CPAP and may be comparable to CPAP in mild disease. PMID:26163056

  15. 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; Kjellberg, Jakob

    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...... selected from the Danish National Patient Registry for the period 1999-2009. We used Cox proportional hazard function to evaluate the all-cause mortality from OSA in middle-aged and elderly males and females who were treated, or not, with CPAP. RESULTS: Female OSA patients had a lower mortality than males......, irrespective of whether they received CPAP treatment. CPAP treatment improved survival, as illustrated by the hazard ratio of 0.62 (P<0.001). This effect was dependent on gender: CPAP had no significant effect on 20- to 39-year-old males and females, but the overall mortality in this age group was small...

  16. 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. PMID:27236054

  17. Effect of Continuous Positive Airway Pressure Ventilation on Platelet-activating Factor and Blood Coagulation Function in Patients with Obstructive Sleep Apnea-hypopnea Syndrome

    International Nuclear Information System (INIS)

    To investigate the effect of continuous positive airway pressure ventilation (CPAP) on platelet-activating factor (PAF) expression and blood coagulation function in patients with obstructive sleep apnea-hypopnea syndrome (OSAS), the blood sample of 40 patients with OSAS were taken before treatment and on the day 30 after treatment respectively. PAF, thromboxane B2 (TXB2), prothrombin time (PT), activated partial thromboplastin time (APTT) and fibrin(FIB) in patients and 37 health controls were detected. The results showed that PAF, TXB2, FIB in OSAS patients before treatment were significantly higher than those of after treatment and control group (P0.05). There were abnormal expression of PAF and hypercoagulability in OSAS patients. CPAP could effectively decrease the expression of PAF, TXB2 and could also correct dysfunction of blood coagulation. It had certain effect in lightening the clinical symptoms in OSAS patients. (authors)

  18. 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.

  19. 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. PMID:25563675

  20. The Influence of Internal Tyre Pressure on Road Friction

    OpenAIRE

    Selig, Michael

    2014-01-01

    Road safety is a very important topic for research and development divisions in the automotive industry. As the tyre is the only link between road surface and vehicle, it plays a very significant role in accident mitigation and prevention. This thesis investigates the influence of internal tyre pressure on the brake distance both experimentally and theoretically. Brake tests were performed using a robotic system and a winch was used to pull a car with locked wheels. For both experiments,...

  1. 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.

  2. Modeling Upper Airway Collapse by a Finite Element Model with Regional Tissue Properties

    OpenAIRE

    Xu, Chun; Brennick, Michael J.; Dougherty, Lawrence; Wootton, David M.

    2009-01-01

    This study presents a new computational system for modeling the upper airway in rats that combines tagged magnetic resonance imaging (MRI) with tissue material properties to predict three-dimensional (3D) airway motion. The model is capable of predicting airway wall and tissue deformation under airway pressure loading up to airway collapse. The model demonstrates that oropharynx collapse pressure depends primarily on ventral wall (tongue muscle) elastic modulus and airway architecture. An ite...

  3. Effects of pentobarbital on upper airway patency during sleep

    OpenAIRE

    Eikermann, M.; Eckert, D.J.; Chamberlin, N.L.; Jordan, A S; Zaremba, S.; Smith, S.; Rosow, C.; Malhotra, A

    2009-01-01

    We hypothesised that pentobarbital would improve upper airway mechanics based on an increase in latency to arousal and amplitude of the phasic genioglossus electromyogram (EMG), and a decrease in the active upper airway critical closing pressure (Pcrit).

  4. Severe acute respiratory failure managed with continuous positive airway pressure and partial extracorporeal carbon dioxide removal by an artificial membrane lung. A controlled, randomized animal study.

    Science.gov (United States)

    Borelli, M; Kolobow, T; Spatola, R; Prato, P; Tsuno, K

    1988-12-01

    Using an animal model of acute respiratory failure (ARF), we evaluated two treatments: conventional mechanical pulmonary ventilation (MV) and continuous positive airway pressure (CPAP) with extracorporeal removal of CO2 by an artificial membrane lung. We developed a model of "mild" ARF and a model of "severe" ARF after ventilating healthy sheep at a peak inspiratory pressure of 50 cm H2O for various lengths of time. Sheep from either injury models were randomly assigned to one of the above treatment groups. All 16 sheep from the model with "severe" ARF died, with progressive deterioration in pulmonary function and multiorgan failure irrespective of the treatment. Of 11 sheep from the model with "mild" ARF treated by MV, only three survived, whereas all 11 sheep from the model with "mild" ARF treated with CPAP and extracorporeal removal of CO2 responded well, and nine sheep ultimately recovered. We conclude that CPAP with extracorporeal removal of CO2 provided a better environment for the recovery in our model with "mild" ARF than the conventional arrangement centered on MV alone. Our studies also suggest that lung injury can progress (i.e., model with "severe" ARF) to where neither of the two treatments can succeed. PMID:3144216

  5. Genioglossal inspiratory activation: central respiratory vs mechanoreceptive influences

    OpenAIRE

    Pillar, Giora; Fogel, Robert B.; Malhotra, Atul; Beauregard, Josée; Edwards, Jill K.; Shea, Steven A.; White, David P.

    2001-01-01

    Upper airway dilator muscles are phasically activated during respiration. We assessed the interaction between central respiratory drive and local (mechanoreceptive) influences upon genioglossal (GG) activity throughout inspiration. GGEMG and airway mechanics were measured in 16 awake subjects during baseline spontaneous breathing, increased central respiratory drive (inspiratory resistive loading; IRL), and decreased respiratory drive (hypocapnic negative pressure ventilation), both prior to ...

  6. The influence of heating rate on the pressure tube microstructure

    International Nuclear Information System (INIS)

    The aim of this paper is the study of the influence of heating rate on the microstructure morphology developed in pressure tube (Zr-2, 5% Nb alloy) at temperatures in the thermal transient conditions similar to LOCA (Loss of Coolant Agent) accident. The samples were tested using some thermal transient scenarios with different rates of heating. The thermal transients are performed at temperatures between 300 deg. C and 900 deg. C with the following heating rates: 5 deg. C/s, 10 deg. C/s and 20 deg. C/s. The average grain size and microhardness determination were performed in cross and longitudinal sections on the blank and tested samples. The analysis of microphotographs and data is presented as figures and diagrams. Some results of these experiments can be used in the study of degradation of the mechanical and micro-structural properties of the pressure tube materials in CANDU reactors. (authors)

  7. Obesity and upper airway control during sleep

    OpenAIRE

    Schwartz, Alan R.; Patil, Susheel P.; Squier, Samuel; Schneider, Hartmut; Kirkness, Jason P.; Smith, Philip L

    2009-01-01

    Mechanisms linking obesity with upper airway dysfunction in obstructive sleep apnea are reviewed. Obstructive sleep apnea is due to alterations in upper airway anatomy and neuromuscular control. Upper airway structural alterations in obesity are related to adipose deposition around the pharynx, which can increase its collapsibility or critical pressure (Pcrit). In addition, obesity and, particularly, central adiposity lead to reductions in resting lung volume, resulting in loss of caudal trac...

  8. Computational Flow Modeling of Human Upper Airway Breathing

    Science.gov (United States)

    Mylavarapu, Goutham

    Computational modeling of biological systems have gained a lot of interest in biomedical research, in the recent past. This thesis focuses on the application of computational simulations to study airflow dynamics in human upper respiratory tract. With advancements in medical imaging, patient specific geometries of anatomically accurate respiratory tracts can now be reconstructed from Magnetic Resonance Images (MRI) or Computed Tomography (CT) scans, with better and accurate details than traditional cadaver cast models. Computational studies using these individualized geometrical models have advantages of non-invasiveness, ease, minimum patient interaction, improved accuracy over experimental and clinical studies. Numerical simulations can provide detailed flow fields including velocities, flow rates, airway wall pressure, shear stresses, turbulence in an airway. Interpretation of these physical quantities will enable to develop efficient treatment procedures, medical devices, targeted drug delivery etc. The hypothesis for this research is that computational modeling can predict the outcomes of a surgical intervention or a treatment plan prior to its application and will guide the physician in providing better treatment to the patients. In the current work, three different computational approaches Computational Fluid Dynamics (CFD), Flow-Structure Interaction (FSI) and Particle Flow simulations were used to investigate flow in airway geometries. CFD approach assumes airway wall as rigid, and relatively easy to simulate, compared to the more challenging FSI approach, where interactions of airway wall deformations with flow are also accounted. The CFD methodology using different turbulence models is validated against experimental measurements in an airway phantom. Two case-studies using CFD, to quantify a pre and post-operative airway and another, to perform virtual surgery to determine the best possible surgery in a constricted airway is demonstrated. The unsteady

  9. 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.

  10. The effect of treating obstructive sleep apnea with positive airway pressure on depression and other subjective symptoms: A systematic review and meta-analysis.

    Science.gov (United States)

    Gupta, Madhulika A; Simpson, Fiona C; Lyons, Danika C A

    2016-08-01

    Patients with obstructive sleep apnea (OSA) frequently present with symptoms of depression and anxiety. The objective of this study is to determine if treatment with positive airway pressure (PAP) improves symptoms of depression and anxiety. A systematic review was conducted to identify clinical trials of PAP that contained a validated measure of depression severity. Meta-analysis was conducted for depression, anxiety, excessive daytime sleepiness (EDS), quality of life (QoL) and respiratory variables. The systematic review included 33 reports. Pre-post-test analysis of PAP showed a moderate effect size (Hedge's g, 95% CI) for depression 0.524 [0.401-0.647], but a low effect size compared to oral placebo (0.355 [0.187-0.524]) and no effect when compared to dental appliances (0.107 [-0.72-0.287]) and sham PAP (-0.049 [-0.292-0.194]). Anxiety, EDS, and QoL showed similar improvement in pre-post-test analysis, but a lack of superiority to dental appliances and sham PAP. PAP was superior to all comparators for respiratory variables. PAP has a moderate clinical effect on symptoms of depression and anxiety in OSA, but it is not superior to dental appliances or sham PAP. The improvement in subjective symptoms, such as depression and anxiety, may be mediated by patient expectations and contact with healthcare providers. PMID:26454823

  11. Upper airway resistance syndrome.

    Science.gov (United States)

    Hasan, N; Fletcher, E C

    1998-07-01

    Many clinicians are familiar with the clinical symptoms and signs of obstructive sleep apnea (OSA). In its most blatant form, OSA is complete airway obstruction with repetitive, prolonged pauses in breathing, arterial oxyhemoglobin desaturation; followed by arousal with resumption of breathing. Daytime symptoms of this disorder include excessive daytime somnolence, intellectual dysfunction, and cardiovascular effects such as systemic hypertension, angina, myocardial infarction, and stroke. It has been recently recognized that increased pharyngeal resistance with incomplete obstruction can lead to a constellation of symptoms identical to OSA called "upper airway resistance syndrome" (UARS). The typical findings of UARS on sleep study are: (1) repetitive arousals from EEG sleep coinciding with a (2) waxing and waning of the respiratory airflow pattern and (3) increased respiratory effort as measured by esophageal pressure monitoring. There may be few, if any, obvious apneas or hypopneas with desaturation, but snoring may be a very prominent finding. Treatment with nasal positive airway pressure (NCPAP) eliminates the symptoms and confirms the diagnosis. Herein we describe two typical cases of UARS. PMID:9676067

  12. All-cause mortality from obstructive sleep apnea in male and female patients with and without continuous positive airway pressure treatment: a registry study with 10 years of follow-up

    OpenAIRE

    Jennum P; Tønnesen P; Ibsen R; Kjellberg J

    2015-01-01

    Poul Jennum,1,2 Philip Tønnesen,1 Rikke Ibsen,3 Jakob Kjellberg4 1Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Glostrup Hospital, Copenhagen, Denmark; 2Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; 3itracks, Aarhus, Denmark, 4Danish National Institute for Local and Regional Government Research, Copenhagen, Denmark Background: More information is needed about the effect on mortality of continuous positive airway pressure (CPAP) ...

  13. Torasik cerrahi sonrası postoperatif pulmoner komplikasyonların önlenmesinde İnsentif spirometre ve Continous Positive Airway Pressure (CPAP)'ın karşılaştırılması

    OpenAIRE

    KOSTANOĞLU, Alis; TARAKCI, Ela; DAYIOĞLU, Enver; DEMİRCİ, Sabriye

    2014-01-01

    Abstrac Aim: Investigating effects of Incentive Spirometry and Continuous Positive Airway Pressure (CPAP) masks on postoperative pulmonary complications in patients who were undergone thoracicsurgery. Material and Methods: The study enrolled totally 30 patients, including 14 female and 16 male patients, who were hemodynamically stable following thoracic surgery. Following the extubation, patients were randomly divided into two groups. “Incentive Spirometry” studies were performed with g...

  14. Spontaneous breathing with airway pressure release ventilation favors ventilation in dependent lung regions and counters cyclic alveolar collapse in oleic-acid-induced lung injury: a randomized controlled computed tomography trial

    OpenAIRE

    Wrigge, Hermann; Zinserling, Jörg; Neumann, Peter; Muders, Thomas; Magnusson, Anders; Putensen, Christian; Hedenstierna, Göran

    2005-01-01

    Introduction Experimental and clinical studies have shown a reduction in intrapulmonary shunt with spontaneous breathing during airway pressure release ventilation (APRV) in acute lung injury. This reduction was related to reduced atelectasis and increased aeration. We hypothesized that spontaneous breathing will result in better ventilation and aeration of dependent lung areas and in less cyclic collapse during the tidal breath. Methods In this randomized controlled experimental trial, 22 pi...

  15. Influence of membrane galactolipids and surface pressure on plastoquinone behaviour.

    Science.gov (United States)

    Hoyo, Javier; Guaus, Ester; Torrent-Burgués, Juan

    2016-10-01

    In this work biomimetic monolayers of a MGDG, monogalactosyldiacylglycerol, and DGDG, digalactosyldiacylglycerol mixture (MD), in a ratio close to that of the thylakoid membranes of oxygenic photosynthetic organisms, have been prepared. The lipid mixture incorporates plastoquinone-9 (PQ), that is the electron and proton shuttle of the photosynthetic reaction centres. The MD:PQ mixtures have been firstly studied using surface pressure-area isotherms. Langmuir-Blodgett (LB) films of those mixtures have been transferred onto a substrate forming a monolayer that mimics one of the bilayer sides of the thylakoid membranes. These monolayers have been characterized topographically and electrochemically. The results show the influence of PQ in the MD matrix and its partial expulsion when increasing the surface pressure, obtaining two main PQ positions in the MD matrix. The calculated apparent electron transfer rate constants indicate a different kinetic control for the reduction and the oxidation of the PQ/PQH2 couple, being kRapp(I)=0.7·10(-6)s(-1), kRapp(II)=2.2·10(-9)s(-1), kOapp(I)=7.4·10(-4)s(-1) and kOapp(II)=5.2·10(-5)s(-1), respectively. The comparison of the different galactolipid:PQ systems that our group has studied is also presented, concluding that the PQ position in the galactolipid matrix can be tuned according to several controlled variables. PMID:27317998

  16. Emergency airway puncture

    Science.gov (United States)

    Emergency airway puncture is the placement of a hollow needle through the throat into the airway. It ... Emergency airway puncture is done in an emergency situation, when someone is choking and all other efforts ...

  17. 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. 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

  18. 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

  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. Continuous positive airway pressure ventilation during whole lung lavage for treatment of alveolar proteinosis -A case report and review of literature

    Directory of Open Access Journals (Sweden)

    Abdelazeem El-Dawlatly

    2011-01-01

    Full Text Available Pulmonary alveolar proteinosis (PAP is a rare disease that affects young population usually in the age group of 20-40 years, characterized by the deposition of lipoproteinacious material in the alveoli secondary to abnormal processing of surfactant by macrophages. We report a case of a 15-year-old female who had history of cough with sputum for 3 days along with fever. She was seen in another hospital and was treated as a case of pneumonia where she received antibiotic but with no improvement. Computerized tomography (CT chest showed diffuse interlobular septal thickening in the background of ground glass opacity giving a picture of crazy paving pattern which was consistent with the diagnosis of PAP. The patient was scheduled to undergo, first right-sided whole lung lavage (WLL under general anesthesia. Endobronchial intubation using left sided 37 Fr double lumen tube. Continuous positive airway pressure (CPAP as described in our previously published report was connected to the right lumen of the endobronchial tube. CPAP ventilation was used during the suctioning of lavage fluid phase in order to improve oxygenation. WLL was done using 5 L of warm heparinized saline (500 i.u/litre. The same procedure was repeated on the left side using 6 L of heparinized normal saline solution. In conclusion, anesthesia in alveolar proteinosis for patients undergoing WLL is challenging to the anesthesiologist. It requires meticulous preoperative preparation with antibiotics, mucolytics and chest physiotherapy. Also it requires careful intraoperative monitoring and proper oxygenation especially during the suctioning phase of the lavaged fluid. With this second case report of successful anesthetic management using the modified CPAP system we recommend with confidence the application of CPAP ventilation to improve oxygenation during WLL.

  1. 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

  2. Serum Levels of Vascular Endothelial Growth Factor and Insulin-like Growth Factor Binding Protein-3 in Obstructive Sleep Apnea Patients: Effect of Continuous Positive Airway Pressure Treatment

    Science.gov (United States)

    Archontogeorgis, Kostas; Nena, Evangelia; Papanas, Nikolaos; Xanthoudaki, Maria; Hatzizisi, Olga; Kyriazis, Georgios; Tsara, Venetia; Maltezos, Efstratios; Froudarakis, Marios; Steiropoulos, Paschalis

    2015-01-01

    Background and Aim: Hypoxia, a major feature of obstructive sleep apnea (OSA), modifies Vascular Endothelial Growth Factor (VEGF) and Insulin-like Growth Factor Binding Protein-3 (IGFBP-3) levels, which contribute to atherogenesis and occurrence of cardiovascular (CV) events. We assessed and compared serum levels of VEGF and IGFBP-3 in newly diagnosed OSA patients and controls, to explore associations with anthropometric and sleep parameters and to study the effect of continuous positive airway pressure (CPAP) treatment on these levels. Materials and Methods: Serum levels of VEGF and IGFBP-3 were measured in 65 OSA patients and 31 age- and body mass index- matched controls. In OSA patients, measurements were repeated after 6 months of CPAP therapy. All participants were non-smokers, without any comorbidities or systemic medication use. Results: At baseline, serum VEGF levels in OSA patients were higher compared with controls (p<0.001), while IGFBP-3 levels were lower (1.41±0.56 vs. 1.61±0.38 μg/ml, p=0.039). VEGF levels correlated with apnea-hypopnea index (r=0.336, p=0.001) and oxygen desaturation index (r=0.282, p=0.007). After 6 months on CPAP treatment, VEGF levels decreased in OSA patients (p<0.001), while IGFBP-3 levels increased (p<0.001). Conclusion: In newly diagnosed OSA patients, serum levels of VEGF are elevated, while IGFBP-3 levels are low. After 6 months of CPAP treatment these levels change. These results may reflect an increased CV risk in untreated OSA patients, which is ameliorated after CPAP therapy. PMID:27006717

  3. 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.

  4. Influence of low-density polyethylene addition on coking pressure

    OpenAIRE

    Melendi, Sonia; Barriocanal, C.; R. Alvarez; M.A. Diez

    2014-01-01

    Different amounts of low-density polyethylene (LDPE) were added to a bituminous coal used to produce metallurgical coke. The effect of the plastic waste on the carbonization process and more exactly, on the coking pressure were investigated. A movable wall oven at semi-pilot scale was used for measuring coking pressure generated. It was found that coking pressure increases for low LDPE addition levels (1-3 wt.%); however higher amounts of LDPE reduce coking pressure. To explain this behavior ...

  5. The influences of positive end expiratory pressure (PEEP) associated with physiotherapy intervention in phase I cardiac rehabilitation

    OpenAIRE

    Borghi-Silva Audrey; Mendes Renata Gonçalves; Costa Fernando de Souza Melo; Di Lorenzo Valéria Amorim Pires; Oliveira Claudio Ricardo de; Luzzi Sérgio

    2005-01-01

    PURPOSE: To evaluate the effects of positive end expiratory pressure and physiotherapy intervention during Phase I of cardiac rehabilitation on the behavior of pulmonary function and inspiratory muscle strength in postoperative cardiac surgery. METHODS: A prospective randomized study, in which 24 patients were divided in 2 groups: a group that performed respiratory exercises with positive airway expiratory pressure associated with physiotherapy intervention (GEP, n = 8) and a group that recei...

  6. 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.

  7. 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.

  8. 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.

  9. 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

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

    OpenAIRE

    Whincup, P H; Cook, D G; Papacosta, O

    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...

  11. 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

  12. 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 tibial artery 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. PMID:27079693

  13. 双水平正压通气在早产儿呼吸窘迫综合征治疗中的应用%A clinical trial of duo positive airway pressure ventilation versus nasal continuous positive airway pressure in treatment of preterm infant with neonatal respiratory distress syndrome after INSURE

    Institute of Scientific and Technical Information of China (English)

    戴立英; 张健; 王琍琍

    2014-01-01

    Objective To explore the efficacy of duo positive airway pressure ventilation in treating preterm infant with neonatal respiratory distress syndrome (RDS). Methods 65 preterm infants admitted to the neonatal intensive care unit from December 2012 to December 2013 were randomly divided into DuoPAP group (34 cases) or NCPAP (31 cases) group. Blood gas analysis(pH value, PaO2, PaCO2 and OI) at 1h, 12h, 24h, and 72h, and incidence of apnea, pulmonary air leak, repeated application of pulmonary surfactant and non-invasive ventilation failure at 72h in the two groups were measured and compared after using intubate surfactant extubate (INSURE). Results OI after non-invasive ventilation at 1h, 12h, and 24h was signiifcantly higherin DuoPAP group than that in NCPAP group P0.05)。结论 DuoPAP治疗NRDS与nCPAP相比能更快改善氧合,减少CO2潴留,减少有创机械通气比例。

  14. 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.

  15. Influence of Cylinder Bore Volume on Pressure Pulsations in a Hermetic Reciprocating Compressor

    OpenAIRE

    Novak, Keith Adam

    2014-01-01

    Suction pressure pulsations created when the suction valve opens are caused by unsteady mass flow through the valve exciting acoustic resonances in the suction plenum. These pressure pulsations influence valve dynamics, compressor performance and compressor noise. This paper will show the importance of including the cylinder bore volume in the flow path analysis in order to accurately calculate pressure pulsations. Pressure pulsations will be calculated using Finite Element Method (FEM) calcu...

  16. Noninvasive clearance of airway secretions.

    Science.gov (United States)

    Hardy, K A; Anderson, B D

    1996-06-01

    Airway clearance techniques are indicated for specific diseases that have known clearance abnormalities (Table 2). Murray and others have commented that such techniques are required only for patients with a daily sputum production of greater than 30 mL. The authors have observed that patients with diseases known to cause clearance abnormalities can have sputum clearance with some techniques, such as positive expiratory pressure, autogenic drainage, and active cycle of breathing techniques, when PDPV has not been effective. Hasani et al has shown that use of the forced exhalatory technique in patients with nonproductive cough still resulted in movement of secretions proximally from all regions of the lung in patients with airway obstruction. It is therefore reasonable to consider airway clearance techniques for any patient who has a disease known to alter mucous clearance, including CF, dyskinetic cilia syndromes, and bronchiectasis from any cause. Patients with atelectasis from mucous plugs and hypersecretory states, such as asthma and chronic bronchitis, patients with pain secondary to surgical procedures, and patients with neuromuscular disease, weak cough, and abnormal patency of the airway may also benefit from the application of airway clearance techniques. Infants and children up to 3 years of age with airway clearance problems need to be treated with PDPV. Manual percussion with hands alone or a flexible face mask or cup and small mechanical vibrator/percussors, such as the ultrasonic devices, can be used. The intrapulmonary percussive ventilator shows growing promise in this area. The high-frequency oscillator is not supplied with vests of appropriate sizes for tiny babies and has not been studied in this group. Young patients with neuromuscular disease may require assisted ventilation and airway oscillations can be applied. CPAP alone has been shown to improve achievable flow rates that will increase air-liquid interactions for patients with these diseases

  17. 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

  18. The UK General Practice Airways Group (GPIAG): its formation, development, and influence on the management of asthma and other respiratory diseases over the last twenty years.

    Science.gov (United States)

    Levy, Mark L; Stephenson, Paul; Barritt, Peter; Bellamy, David; Haughney, John; Hilton, Sean; Holmes, Steve; Jones, Kevin; Neville, Ron; Price, David; Ryan, Dermot; Smith, Anne

    2007-06-01

    This article describes the formation and development of the UK General Practice Airways Group (GPIAG), from its inception as a small respiratory special-interest group founded by six general practitioners in 1987 through to its transformation into the largest primary care specialist society in the UK. It highlights the historical context in which the GPIAG was founded - at a time when there was increasing concern about under-treatment and under-diagnosis of asthma in primary care - and describes the way in which its foundation was one of the major influences that led to profound innovation in the primary care management of respiratory disease as well as changes across the primary/secondary care interface. The GPIAG is now a registered charity, has an expanding membership, and has acquired a high profile both nationally and internationally as an advisory body on policy and strategy for the management of respiratory disease in primary care. This review is a 20th anniversary tribute not only to those who have contributed to the success of the GPIAG over the last twenty years, but also to its current membership who enable the GPIAG to continue working towards its charitable aim of "optimal respiratory care for all." PMID:17530149

  19. Upper airway test (image)

    Science.gov (United States)

    An upper airway biopsy is obtained by using a flexible scope called a bronchoscope. The scope is passed down through ... may be performed when an abnormality of the upper airway is suspected. It may also be performed as ...

  20. Response to Commentary on "The influence of lung airways branching structure and diffusion time on measurements and models of short-range 3He gas MR diffusion".

    Science.gov (United States)

    Parra-Robles, Juan; Wild, Jim M

    2014-02-01

    Our extensive investigation of the cylinder model theory through numerical modelling and purpose-designed experiments has demonstrated that it does produce inaccurate estimates of airway dimensions at all diffusion times currently used. This is due to a variety of effects: incomplete treatment of non-Gaussian effects, finite airway size, branching geometry, background susceptibility gradients and diffusion time dependence of the (3)He MR diffusion behaviour in acinar airways. The cylinder model is a good starting point for the development of a lung morphometry technique from (3)He diffusion MR but its limitations need to be understood and documented in the interest of reliable clinical interpretation. PMID:24342570

  1. The influence of hydrostatic pressure on tissue engineered bone development.

    Science.gov (United States)

    Neßler, K H L; Henstock, J R; El Haj, A J; Waters, S L; Whiteley, J P; Osborne, J M

    2016-04-01

    The hydrostatic pressure stimulation of an appropriately cell-seeded porous scaffold within a bioreactor is a promising method for engineering bone tissue external to the body. We propose a mathematical model, and employ a suite of candidate constitutive laws, to qualitatively describe the effect of applied hydrostatic pressure on the quantity of minerals deposited in such an experimental setup. By comparing data from numerical simulations with experimental observations under a number of stimulation protocols, we suggest that the response of bone cells to an applied pressure requires consideration of two components; (i) a component describing the cell memory of the applied stimulation, and (ii) a recovery component, capturing the time cells require to recover from high rates of mineralisation. PMID:26796221

  2. How does serum brain natriuretic peptide level change under nasal continuous positive airway pressure in obstructive sleep apnea-hypopnea syndrome?

    Science.gov (United States)

    Msaad, Sameh; Marrakchi, Rim; Grati, Malek; Gargouri, Rahma; Kammoun, Samy; Jammoussi, Kamel; Yangui, Ilhem

    2016-01-01

    Background Obstructive sleep apnea-hypopnea syndrome (OSAHS) is associated with cardiovascular morbidity and mortality, which can be improved by using continuous positive airway pressure (CPAP) therapy. However, the pathophysiological links between the two kinds of disease and the mechanism of the CPAP effect remain incompletely understood. We aimed to inquire into the myocardial involvement in this relationship. We suggested that serum brain natriuretic peptide (BNP) is sensitive enough to detect myocardial stress caused by OSAHS. Design and methods Sixty-four subjects without cardiovascular disease (21 controls, 24 normotensive OSAHS patients, and 19 hypertensive OSAHS patients) were analyzed for serum BNP at baseline and serially over 6 months. CPAP was applied to 23 patients with severe OSAHS. Results At baseline, the serum BNP levels were significantly higher (p=0.0001) in the OSAHS group (22.3±14.79 pg/ml) than in the control group (9.2±6.75 pg/ml). Increased serum BNP levels were significantly associated with mean transcutaneous oxygen saturation (SpO2) (psleep time spent with SpO2 lower than 90% (p=0.002). All patients with elevated BNP levels (≥37 pg/ml) had moderate or severe OSAHS (11/43 OSAHS patients). The more severe the OSAHS, the higher the BNP levels were. However, only the difference between severe and mild OSAHS was statistically significant (p=0.029). Hypertensive OSAHS patients had the highest baseline BNP levels (27.7±16.74 pg/ml). They were significantly higher (p=0.001) than in normotensive OSAHS patients (18±11.72 pg/ml) (p=0.039) and the controls (9.2±6.75 pg/ml). As compared with baseline, treatment with CPAP significantly decreased BNP levels in both hypertensive and normotensive OSAHS patients (respectively, from 36±16.10 to 29.7±14.29 pg/ml, p<0.001, and from 20±10.09 to 16±8.98 pg/ml, p<0.001). In contrast, the BNP levels slightly increased in the controls (from 9.2±6.75 to 9.5±7.02 pg/ml, p=0.029), but there was no

  3. Laryngeal mask airway: an alternative for the difficult airway.

    Science.gov (United States)

    Jones, J R

    1995-10-01

    The laryngeal mask airway (LMA) was invented by Dr. Archie Brain at the London Hospital, Whitechapel, in 1981. Dr. Brain's main objective for the LMA was that it would provide a better method of maintaining a patient's airway than by face mask. Also, the LMA would be less hemodynamically stressful than with insertion of an endotracheal tube. The LMA consists of a silicone rubber tube connected to a miniature silicone mask. The perimeter of the mask consists of an inflatable elliptical cuff, which forms a tip at the distal aspect of the LMA. The aperture bars in the dome of the mask lift the epiglottis away, so the lumen remains unobstructive. The LMA forms a low pressure seal around the larynx. The LMA is contraindicated in any situation where the patient is at risk for pulmonary aspiration. The LMA is not a substitute for a properly placed endotracheal tube in this situation. The American Society of Anesthesiologists' difficult airway algorithm recommends the insertion of an LMA when ventilation and/or intubation are difficult. The distal aperture of the LMA is in close approximation to the vocal cords, so a 6.0-mm internal diameter endotracheal tube can be passed over an intubating stylet or a pediatric fiberoptic bronchoscope to secure a patient's airway. PMID:7502644

  4. 双水平正压通气与持续呼吸道正压通气在早产儿呼吸窘迫综合征中的比较研究%Comparison of Bi-level positive airway pressure and continuous positive airway pressure in preterm infants with respiratory distress syndrome

    Institute of Scientific and Technical Information of China (English)

    白丽亚; 赵莉; 马玲彦; 王丹

    2015-01-01

    Objective:To compare the therapeutic effects for nasal bi-level positive airway pressure (BiPAP) and nasal continuous positive airway pressure (NCPAP) combined with pulmonary surfactant in preterm infants with respiratory distress syndrome (RDS) and to determine whether can reduce the need for intubation and mechanical ventilation.Methods: In this single-center, randomized controlled trial, preterm infants (gestational ages were 28-34+6weeks) with RDS were randomly assigned to BiPAP group (24 cases) and NCPAP group(25 cases). If the 2 noninvasive ventilation were not effective, intubation was administered as rescue therapy. The primary outcome was the need for mechanical ventilation within the first 24 hours, 48 hours, 78 hours of life. The secondary outcomes were incidence of pneumothorax, incidence of necrotizing enterocolitis, incidence of intraventricular hemorrhage(grade 3 and grade 4).Results: Rates of intubation in the first 24 hours did not differ significantly between the BiPAP group and NCPAP group, however, significantly more infants in the BiPAP group remained extubated compared with those in the NCPAP group within 48 hours, 72 hours (x2=4.056,x2=4.325;P<0.05). No significant differences were noted between the 2 treatment groups for the secondary outcomes.Conclusion: BiPAP can decrease the need for mechanical ventilation compared with NCPAP after 24 hours.%目的:比较双水平正压通气(BiPAP)和持续呼吸道正压通气(NCPAP)联合肺表面活性物质(PS)在早产儿呼吸窘迫综合征(RDS)中的应用效果,探讨是否可以降低气管插管有创呼吸支持率。方法:将胎龄在28~34周(+6 d)的RDS早产儿随机分为BiPAP组(24例)和NCPAP组(25例),常规使用PS进行替代治疗,若这两种方式不能维持患儿生命体征则使用气管内插管,接呼吸机辅助呼吸。主要观察指标为出生24 h、48 h及72 h插管有创呼吸支持率,次要观察指标为气胸发病率、坏死性小肠结肠炎

  5. Comparison of different continuous positive airway pressure titration methods for obstructive sleep apnea hypopnea syndrome%正压通气治疗中手动及自动压力滴定模式比较

    Institute of Scientific and Technical Information of China (English)

    李京京; 叶京英; 张鹏; 亢丹; 曹鑫; 张玉焕; 丁秀; 郑莉; 李鸿光

    2014-01-01

    Objective To explore whether there were differences between the results of automatic titration and the results of manual titration for positive airway pressure treatment in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and its influencing factors,the results might provide a theoretical basis for the rational use of two pressure titration methods.Methods Sixty one patients with OSAHS were included in this study.All patients underwent a manual titration and an automatic titration within one week.The clinical informations,polysomnography data,and the results of both two titration of all patients were obtained for analysis.Results The overall apnea/hypopnea index was (63.1 ± 17.7)/h,with a range of 14.9/h to l10.4/h.The treatment pressure of manual titration was (8.4 ± 2.1)cmH2O,which was significantly lower than the treatment pressure of automatic titration,(11.5 ± 2.7) cmH2O (t =-9.797,P<0.001).After using a △P of 3 cmH2O for the cutoff value (△p was defined as the difference of automatic titration and manual titration),it was found that the pressure of automatic titration was significantly higher in patients with a △P > 3 cmH2O than in patients with a △P≤3 cmH2O,which was (13.3±2.3)cmH2O vs (10.0 ±2.0)cmH2O (t =-6.159,P<0.001).However,there were no differences for the pressure of manual titration between these two groups,which was (8.6 ± 2.4) cmH2O vs (8.3 ± 2.0) cmH2O (P > 0.05).There was no significant difference in age,body mass index,neck circumference,abdomen circumference,apnea hypopnea index,and arterial oxygen saturation between these two groups.Conclusions The treatment pressure of automatic titration is usually higher than that of manual titration.For patients with a high treatment pressure which is derived from automatic titration,a suggestion about manual titration could be given to decrease the potential treatment pressure of continuous positive airway pressure,which may be helpful in improving the

  6. Influence of pressure on the Fermi surface of niobium

    International Nuclear Information System (INIS)

    The effects of pressure on selected de Haas--van Alphen frequencies in niobium have been measured. The frequency shifts, including a relatively large negative shift for the jungle-gym arms, can be explained by a model which uses a Slater-Koster interpolation of augmented-plane-wave Xα bands which had been calculated for two lattice spacings

  7. 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.

  8. Effects of age and gender on upper airway, lower airway and upper lip growth

    Directory of Open Access Journals (Sweden)

    Renata de Cassia Gonçalves

    2011-06-01

    Full Text Available The aim of the present retrospective study was to evaluate the influence of age and gender on upper and lower airway width and upper lip length. In this study, 390 lateral cephalograms were divided into 13 age groups (ranging from 6 to 18 years and were analyzed. The intergroup differences were analyzed using a MANOVA (Multivariate Analysis of the Variance, and the intragroup differences were analyzed using an ANOVA (Analysis of the Variance and Tukey's test. The results of the present study indicated that although the airway width and the upper lip length increased with age, the lower airway width exhibited variable growth between the ages of six and eighteen years. The airway width was significantly greater in females than males, whereas the upper airway width was similar between these two genders. The lip length was significantly shorter in females than males. The lower airway width and upper lip length were significantly different between males and females, whereas the upper airway width was similar for the genders. The upper airway width and upper lip exhibited incremental growth between the ages of six and eighteen years. The upper lip closely followed the growth pattern of the upper airway width; the growth plateaued between the ages of 6 and 9 years, increased from 9 to 16 years and plateaued from 16 to 18 years.

  9. Influence of negative pressurization on airborne microbial and radon levels

    Energy Technology Data Exchange (ETDEWEB)

    Kalliokoski, P.; Korhonen, P.; Kokotti, H.; Pasanen, A.L.; Rautiala, S.; Rantamaeki, J.

    1999-07-01

    The negative pressure inside a building is the main driving force for the entry of both radon and fungal spores. This study was conducted to test the suitability of depressurization to facilitate simultaneously the detection of fungal growth within the lower parts of building envelope and the risk of radon entry. Pressure difference was increased in three steps to 24--28 Pa in two wooden buildings known to suffer from long-term water damages. At the end, pulses of negative pressure were generated. Airborne viable fungal counts, radon and particle counts were followed during the tests together with the ventilation rate and particle count. The absolute concentrations of the impurities studied did not increase significantly or even decreased during the tests due to enhanced ventilation. However, when the increase in the ventilation rate was taken into consideration it was found that the entry rate of all the contaminants increased. The changes were larger in the tighter building where the radon entry rate increased systematically with the pressure difference reaching finally 13.8-fold level compared to the initial value. In the less tight building, the corresponding highest radon entry rate ratio was 9.5. Very large increases, up to 42-fold, were observed in the viable spore count ratio in the tighter building during the tests. In the leaky building, the changes were again considerably smaller; the maximum ratio was 4.2. Increases in particle emissions were smaller than those observed in fungal counts. The pulses were less effective than continuous depressurization. The results show that negative pressurization can be used to increase the release of fungal spores in order to detect hidden fungal growth. This kind of test is especially effective if there are no major leaks in the clean part of the building envelope. The method allows simultaneous rapid checking of need for radon mitigation.

  10. Airways disorders and the swimming pool.

    Science.gov (United States)

    Bougault, Valérie; Boulet, Louis-Philippe

    2013-08-01

    Concerns have been expressed about the possible detrimental effects of chlorine derivatives in indoor swimming pool environments. Indeed, a controversy has arisen regarding the possibility that chlorine commonly used worldwide as a disinfectant favors the development of asthma and allergic diseases. The effects of swimming in indoor chlorinated pools on the airways in recreational and elite swimmers are presented. Recent studies on the influence of swimming on airway inflammation and remodeling in competitive swimmers, and the phenotypic characteristics of asthma in this population are reviewed. Preventative measures that could potentially reduce the untoward effects of pool environment on airways of swimmers are discussed. PMID:23830132

  11. 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.

  12. Influence of caffeine on blood pressure and platelet aggregation

    OpenAIRE

    2000-01-01

    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, par...

  13. The influence of social pressure and nationality on individual decisions: evidence from the behaviour of referees

    OpenAIRE

    Peter Dawson; Stephen Dobson

    2008-01-01

    This study considers the influences on agents’ decisions in an international context. Using data from five seasons of European cup football matches it is found that referees favour home teams when awarding yellow and red cards. Previous research on referee decisions in national leagues has identified social pressure as a key reason for favouritism. While social pressure is also found to be an important influence in this study, the international setting shows that nationality is another import...

  14. Radial Body Forces Influence on FGM and Non-FGM Cylindrical Pressure Vessels

    OpenAIRE

    Jacob Nagler

    2016-01-01

    This study deals with the influence of radial body forces on FGM and non-FGM pressure vessels. It contains an extended overview of pressure vessels made from both kinds of material. Furthermore, full mathematical development of stress-strain field for both kinds of cylindrical vessels while being influenced by body forces has been performed. In addition, a new power law model for FGM materials was suggested and discussed. Finally, tables of composed plastic-elastic states are discussed.

  15. Influence of the initial pressure in bubble media on the detonation wave parameters

    Science.gov (United States)

    Sychev, A. I.

    2015-04-01

    The influence of the initial pressure in bubble media on the initiation, structure, velocity, and pressure of detonation waves in single-component bubble media is studied. The test medium (bubbles of a stoichiometric acetylene-oxygen mixture in a hydroglyceric solution) falls under the category of "chemically inactive liquid—bubbles of a chemically active gas." It is found that one can effectively control the parameters of bubble detonation waves by varying the initial pressure in the bubble medium.

  16. Neuromechanical control of the isolated upper airway of mice

    OpenAIRE

    Liu, Audrey; Pichard, Luis; Schneider, Hartmut; Patil, Susheel P.; Smith, Philip L; Polotsky, Vsevolod; Schwartz, Alan R.

    2008-01-01

    We characterized the passive structural and active neuromuscular control of pharyngeal collapsibility in mice and hypothesized that pharyngeal collapsibility, which is elevated by anatomic loads, is reduced by active neuromuscular responses to airflow obstruction. To address this hypothesis, we examined the dynamic control of upper airway function in the isolated upper airway of anesthetized C57BL/6J mice. Pressures were lowered downstream and upstream to the upper airway to induce inspirator...

  17. The Physiologically Difficult Airway

    Directory of Open Access Journals (Sweden)

    Jarrod M. Mosier

    2015-12-01

    Full Text Available Airway management in critically ill patients involves the identification and management of the potentially difficult airway in order to avoid untoward complications. This focus on difficult airway management has traditionally referred to identifying anatomic characteristics of the patient that make either visualizing the glottic opening or placement of the tracheal tube through the vocal cords difficult. This paper will describe the physiologically difficult airway, in which physiologic derangements of the patient increase the risk of cardiovascular collapse from airway management. The four physiologically difficult airways described include hypoxemia, hypotension, severe metabolic acidosis, and right ventricular failure. The emergency physician should account for these physiologic derangements with airway management in critically ill patients regardless of the predicted anatomic difficulty of the intubation.

  18. Influence of pressure and humidity on ethanol distillery power production

    International Nuclear Information System (INIS)

    A distillery for the Generation of Renewable Energy Integrated to Food Production (GERIPA), that produces 125 000 L/day of ethanol, presents advantages in comparison with the traditional distilleries. In this paper the available thermal energy in sugar cane and sorghum, bagasse and straw, and also in biogas are calculated. This energy produces vapor for the process and electricity, using a boiler with 88 % of efficiency and a two stages with intermediate extraction turbine. The dependence of electric power surplus with vapor pressure is evaluated, finding that between 60 and 100 MPa, the electric power surplus reaches 7.15 to 7.82 MW. This electricity can be send to the electro-energetic system. The effective efficiency is calculated for 6 to 10 MPa finding values lower than 25 %. It is shown that a bagasse dryer can be used to increase the efficiency. (author)

  19. Influences of oxygen partial pressure on YBCO grain growth by a zone melting method

    International Nuclear Information System (INIS)

    This study reports investigation on influences of Y endash Ba endash Cu endash O compounds solidification under different oxygen partial pressures by a zone melting method. In Y endash Ba endash Cu endash O system, P(O2) ranged from 0.02 to 1 atm, following reaction occurred during heating: YBa2Cu3O6+δ(Y123)→Y2BaCuO5(Y211)+L. With an increase of oxygen partial pressure or decrease of pulling rate, the morphology of solidified interface changed from mushy to equiaxed, cellular, and planar. The continuous Y123 grains were readily obtained under high oxygen partial pressure. Based on the constitutional supercooling theory and combining the result of the yttrium solubility limit for different oxygen partial pressures, the influences of oxygen partial pressure on Y123 morphological evolution were clarified. copyright 1996 Materials Research Society

  20. The influence of gouge defects on failure pressure of steel pipes

    International Nuclear Information System (INIS)

    Failure pressure of API X42 steel pipes with gouge defects was estimated through a nonlinear finite element (FE) analysis. The effect of gouge length on failure pressure of different pipe diameters was investigated. Stress modified critical strain (SMCS) model was applied as in predicting the failure of the pipe. The model uses strain based criteria to predict the failure. For validation of the model, the FE results were compared to experimental data in literature showing overall good agreement. The results show that the gouge length has significant influence on failure pressure. A smaller pipe diameter gives highest value of failure pressure

  1. 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.

  2. Baby cuff as a reason for laryngeal mask airway cuff malfunction during airway management for anesthesia

    OpenAIRE

    Jafar Rahimi Panahi; Ata Mahmoodpoor; Golzari, Samad E. J.; Hassan Soleimanpour

    2014-01-01

    Placement of laryngeal mask airway (LMA) is a blind procedure without requiring laryngoscopy. The reported success rate for LMA insertion at the first attempt is almost 95%; however, many functioning LMAs may not be in an ideal anatomic place. It seems that disposable LMAs have more stable cuff pressure compared to reusable LMAs; therefore, Anesthesiologists should bear in mind this fact when using reusable LMAs to achieve a proper sealing and safe airway management. In this report, we introd...

  3. The influence of atmospheric pressure on landfill methane emissions

    International Nuclear Information System (INIS)

    Landfills are the largest source of anthropogenic methane (CH4) emissions to the atmosphere in the United States. However, few measurements of whole landfill CH4 emissions have been reported. Here, we present the results of a multi-season study of whole landfill CH4 emissions using atmospheric tracer methods at the Nashua, New Hampshire Municipal landfill in the northeastern United States. The measurement data include 12 individual emission tests, each test consisting of 5-8 plume measurements. Measured emissions were negatively correlated with surface atmospheric pressure and ranged from 7.3 to 26.5 m3 CH4 min-1. A simple regression model of our results was used to calculate an annual emission rate of 8.4x106 m3 CH4 year-1. These data, along with CH4 oxidation estimates based on emitted landfill gas isotopic characteristics and gas collection data, were used to estimate annual CH4 generation at this landfill. A reported gas collection rate of 7.1x106 m3 CH4 year-1 and an estimated annual rate of CH4 oxidation by cover soils of 1.2x106 m3 CH4 year-1 resulted in a calculated annual CH4 generation rate of 16.7x106 m3 CH4 year-1. These results underscore the necessity of understanding a landfill's dynamic environment before assessing long-term emissions potential

  4. Mechanisms Influencing Circadian Blood Pressure Patterns Among Individuals with HIV.

    Science.gov (United States)

    Kent, Shia T; Burkholder, Greer A; Tajeu, Gabriel S; Overton, E Turner; Muntner, Paul

    2015-11-01

    HIV+ individuals have an increased risk for cardiovascular disease (CVD), but the mechanisms behind this association are poorly understood. While hypertension is a well-established CVD risk factor, clinic-based blood pressure (BP) assessment by itself cannot identify several important BP patterns, including white coat hypertension, masked hypertension, nighttime hypertension, and nighttime BP dipping. These BP patterns can be identified over a 24-h period by ambulatory BP monitoring (ABPM). In this review, we provide an overview of the potential value of conducting ABPM in HIV+ individuals. ABPM phenotypes associated with increased CVD risk include masked hypertension (i.e., elevated out-of-clinic BP despite non-elevated clinic BP), nighttime hypertension, and a non-dipping BP pattern (i.e., a drop in BP of sleep disturbance, and autonomic dysfunction have been commonly reported in HIV+ persons. Additionally, although antiretroviral therapy (ART) is associated with lower AIDS-related morbidity and CVD risk, the mitochondrial toxicity, oxidative stress, lipodystrophy, and insulin resistance associated with long-term ART use potentially lead to adverse ABPM phenotypes. Existing data on ABPM phenotypes in the setting of HIV are limited, but suggest an increased prevalence of a non-dipping BP pattern. In conclusion, identifying ABPM phenotypes may provide crucial information regarding the mechanisms underlying the excess CVD risk in HIV+ individuals. PMID:26429228

  5. 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.

  6. 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.

  7. Influence of oxygen partial pressure on growth morphologies in unidirectionally solidified YBCO-Ag superconducting composites

    International Nuclear Information System (INIS)

    YBCO/Ag superconducting composites were fabricated by the unidirectional solidification method under various oxygen partial pressures. The effect of oxygen partial pressure on the growth interface stability and the morphology of Y1Ba2Cu3Ox (Y123)-Ag composite was investigated. The growth interface changed from planar to not planar with decreasing oxygen partial pressure. This phenomenon indicated that the interface stability was dominantly affected by the slope of liquidus, which is a significant function of the oxygen partial pressure. The morphology of the Y123-Ag composite was also strongly influenced by the oxygen partial pressure. In the case of 0.21 atm oxygen partial pressure (Po2), rod-like silver particles elongated along the growth direction were formed around the bottom of the facet crystal. On the other hand, spherical silver droplets were entrapped at the grain boundaries in the case of Po2 = 1atm. (author)

  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. 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

    2011-01-01

    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. PMID:21541337

  10. 21 CFR 868.5115 - Device to relieve acute upper airway obstruction.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Device to relieve acute upper airway obstruction... relieve acute upper airway obstruction. (a) Identification. The device is a raised, rounded pad that, in... expulsion pressure to remove the obstruction to relieve acute upper airway obstruction. (b)...

  11. Engineering Airway Epithelium

    OpenAIRE

    John P. Soleas; Paz, Ana; Marcus, Paula; McGuigan, Alison; Waddell, Thomas K.

    2012-01-01

    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 fun...

  12. Conquering the difficult airway.

    Science.gov (United States)

    Gandy, William E

    2008-01-01

    Every medic should practice regularly for the inevitable difficult airway case. Practice should include review of the causes of difficult airways, as well as skill practice. Having a preassembled airway kit can make your response to an unexpected difficult situation easier. Of all the devices mentioned, the bougie is the airway practitioner's best friend. Using the BURP technique, if not contraindicated, together with the bougie will enable you to intubate many difficult patients with confidence. Remember, "If your patient cannot breathe, nothing else matters. PMID:18251307

  13. The influence of pressure on the photoluminescence properties of a terbium-adipate framework

    International Nuclear Information System (INIS)

    The influence of pressure (over the 0–4.7 GPa range) on the photoluminescence emissions and crystal structure of the known 3D terbium-adipate metal-organic framework material Tb-GWMOF6 has been evaluated by high-pressure single-crystal X-ray diffraction and spectroscopic techniques. The results from this study show that this complex lanthanide framework structure undergoes three phase transitions within the 0–4 GPa pressure range that involve alterations in the number of symmetry independent Tb3+ ion sites within the crystal lattice. These pressure induced modifications to the structure of Tb-GWMOF6 lead to pronounced changes in the profiles of the 5D4→7F5 emission spectra of this complex. - Graphical abstract: The influence of pressure on the structure and photoluminescence emissions of a 3D terbium-adipate framework. - Highlights: • High-pressure luminescence spectra for a Tb framework were collected. • High-pressure single-crystal XRD experiments were conducted with the Tb Framework. • The framework undergoes two pressure-induced phase transitions. • The three phases of the material show different photoluminescence behaviour

  14. 无创气道正压通气联合生脉注射液治疗心力衰竭的临床研究%Clinical research of non-invasive positive airway pressure ventilation combined with Shengmai injection ;in the treatment of chronic heart failure

    Institute of Scientific and Technical Information of China (English)

    林能波; 郑炜华; 张妙华

    2015-01-01

    目的:探讨无创气道正压通气联合生脉注射液对慢性心力衰竭(CHF)患者心功能以及心率的影响。方法80例慢性心力衰竭患者随机分为治疗组和对照组,各40例。对照组采用常规治疗,治疗组在对照组治疗基础上,给予无创气道正压通气联合生脉注射液治疗,记录治疗前后患者的症状、心脏功能指标[左室射血分数(LVEF)、心输出量(CO)、心搏出量(SV)]、血气指标[血氧饱和度(SaO2)、氧分压(PO2)、二氧化碳分压(PCO2)]情况。结果两组患者治疗后临床症状和SaO2、PO2、PCO2均有所改善, CO、SV、LVEF均明显增高,且治疗组的效果明显优于对照组(P<0.05)。结论与传统治疗相比,无创气道正压通气联合生脉注射液治疗且能明显改善慢性心力衰竭患者心功能及心率。%Objective To investigate influence of non-invasive positive airway pressure ventilation combined with Shengmai injection on cardiac function and heart rate in chronic heart failure (CHF) patients. Methods A total of 80 chronic heart failure patients were randomly divided into treatment group and control group, with 40 cases in each group. The control group received conventional treatment, and the treatment group received additional non-invasive positive airway pressure ventilation combined with Shengmai injection. Records were made on symptoms, cardiac function indexes [left ventricular ejection fraction (LVEF), cardiac output (CO), stroke volume (SV)], and blood gas indexes [oxyhemoglobin saturation (SaO2), partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2)] before and after treatment. Results Both groups had improved clinical symptoms, SaO2, PO2, and PCO2, and their CO, SV, and LVEF were all obviously increased. The treatment group had much better effects than the control group (P<0.05). Conclusion Compared with traditional treatment, non-invasive positive airway pressure ventilation combined with

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. Influence of Negative-Pressure Wound Therapy on Tissue Oxygenation of the Foot

    OpenAIRE

    Shon, Yoo-Seok; Lee, Ye-Na; Jeong, Seong-Ho; Dhong, Eun-Sang; Han, Seung-Kyu

    2014-01-01

    Background Negative-pressure wound therapy (NPWT) is believed to accelerate wound healing by altering wound microvascular blood flow. Although many studies using laser Doppler have found that NPWT increases perfusion, recent work using other modalities has demonstrated that perfusion is reduced. The purpose of this study was to investigate the influence of NPWT on tissue oxygenation of the foot, which is the most sensitive region of the body to ischemia. Methods Transcutaneous partial pressur...

  20. Numerical Study on Crack Propagation in Brittle Jointed Rock Mass Influenced by Fracture Water Pressure

    OpenAIRE

    Yong Li; Hao Zhou; Weishen Zhu; Shucai Li; Jian Liu

    2015-01-01

    The initiation, propagation, coalescence and failure mode of brittle jointed rock mass influenced by fissure water pressure have always been studied as a hot issue in the society of rock mechanics and engineering. In order to analyze the damage evolution process of jointed rock mass under fracture water pressure, a novel numerical model on the basis of secondary development in fast Lagrangian analysis of continua (FLAC3D) is proposed to simulate the fracture development of jointed rock mass u...

  1. Measure Method of Submarine Pressure Hull Radial Initial Deflection Influenced By Different Selection of Common Point

    Directory of Open Access Journals (Sweden)

    Peng Fei

    2015-01-01

    Full Text Available While using Electronic Total Station to measure the deflection of the pressure hull, the measurement error was influenced by different selection of common points. To solve this problem, the coordinate values of pressure hull profiles were established at two different coordinate measuring stations. Selecting different position and number of common points to solve the analog circle initial deflection, we obtained the variation of the initial deflection calculation affected by analyzing the initial deflection and middle error of the measure point. The Simulation results show that the common point should be evenly distributed on the pressure hull, and the number of common points should be controlled at 4-7.

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

    Science.gov (United States)

    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; Sõber, 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; Sjögren, 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; Nguyen, Khanh-Dung Hoang; Lehtimäki, 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; Kähönen, Mika; Viikari, Jorma; Adair, Linda S; Lee, Nanette R; Chen, Ming-Huei; Olden, Matthias; Pattaro, Cristian; Bolton, Judith A Hoffman; Köttgen, Anna; Bergmann, Sven; Mooser, Vincent; Chaturvedi, Nish; Frayling, Timothy M; Islam, Muhammad; Jafar, Tazeen H; Erdmann, Jeanette; Kulkarni, Smita R; Bornstein, Stefan R; Grässler, Jürgen; Groop, Leif; Voight, Benjamin F; Kettunen, Johannes; Howard, Philip; Taylor, Andrew; Guarrera, Simonetta; Ricceri, Fulvio; Emilsson, Valur; Plump, Andrew; Barroso, Inês; 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; Soler Artigas, Maria; 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; Stančáková, 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; Lyytikäinen, Leo-Pekka; Soininen, Pasi; Tukiainen, Taru; Würtz, Peter; Ong, Rick Twee-Hee; Dörr, Marcus; Kroemer, Heyo K; Völker, Uwe; Völzke, 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; Järvelin, Marjo-Riitta; Psaty, Bruce M; Abecasis, Gonçalo R; Chakravarti, Aravinda; Elliott, Paul; van Duijn, Cornelia M; Newton-Cheh, Christopher; Levy, Daniel; Caulfield, Mark J; Johnson, Toby

    2011-10-01

    Blood pressure is a heritable trait 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). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention. PMID:21909115

  3. Influence of ambient air pressure on the energy conversion of laser-breakdown induced blast waves

    International Nuclear Information System (INIS)

    Influence of ambient pressure on energy conversion efficiency from a Nd : glass laser pulse (λ = 1.053 µm) to a laser-induced blast wave was investigated at reduced pressure. Temporal incident and transmission power histories were measured using sets of energy meters and photodetectors. A half-shadowgraph half-self-emission method was applied to visualize laser absorption waves. Results show that the blast energy conversion efficiency ηbw decreased monotonically with the decrease in ambient pressure. The decrease was small, from 40% to 38%, for the pressure change from 101 kPa to 50 kPa, but the decrease was considerable, to 24%, when the pressure was reduced to 30 kPa. Compared with a TEA-CO2-laser-induced blast wave (λ = 10.6 µm), higher fraction absorption in the laser supported detonation regime ηLSD of 90% was observed, which is influenced slightly by the reduction of ambient pressure. The conversion fraction ηbw/ηLSD≈90% was achieved at pressure >50 kPa, which is significantly higher than that in a CO2 laser case. (paper)

  4. Hemodynamic responses and upper airway morbidity following tracheal intubation in patients with hypertension: Conventional laryngoscopy versus an intubating laryngeal mask airway

    OpenAIRE

    Elif Bengi Sener; Emre Ustun; Burcu Ustun; Binnur Sarihasan

    2012-01-01

    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...

  5. Airway distensibility in Chronic Obstructive Airway Disease

    DEFF Research Database (Denmark)

    Winkler Wille, Mathilde Marie; Pedersen, Jesper Holst; Dirksen, Asger; Petersen, Jens; De Bruijne, Marleen

    2013-01-01

    airway distensibility, defined as the ratio of relative change in lumen diameter to the relative change in total lung volume (TLV) divided by predicted total lung capacity (pTLC) . Methods – We included 1900 participants from the Danish Lung Cancer Screening Trial (DLCST); all randomized to annual low......-dose CT for a period of 5 years (table 1). Images were reconstructed both with high contrast resolution (3 mm, kernel C) for emphysema analysis and with high spatial resolution (1 mm, kernel D) for airway analysis. Images were analysed by in-house developed software designed to segment lungs and localize......), 10-20% (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...

  6. 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…

  7. Dynamics of Surfactant Liquid Plugs at Bifurcating Lung Airway Models

    Science.gov (United States)

    Tavana, Hossein

    2013-11-01

    A surfactant liquid plug forms in the trachea during surfactant replacement therapy (SRT) of premature babies. Under air pressure, the plug propagates downstream and continuously divides into smaller daughter plugs at continuously branching lung airways. Propagating plugs deposit a thin film on airway walls to reduce surface tension and facilitate breathing. The effectiveness of SRT greatly depends on the final distribution of instilled surfactant within airways. To understand this process, we investigate dynamics of splitting of surfactant plugs in engineered bifurcating airway models. A liquid plug is instilled in the parent tube to propagate and split at the bifurcation. A split ratio, R, is defined as the ratio of daughter plug lengths in the top and bottom daughter airway tubes and studied as a function of the 3D orientation of airways and different flow conditions. For a given Capillary number (Ca), orienting airways farther away from a horizontal position reduced R due to the flow of a larger volume into the gravitationally favored daughter airway. At each orientation, R increased with 0.0005 surfactant distribution in airways and develop effective SRT strategies.

  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. PMID:26897434

  9. Investigation of mucus transport in an idealized lung airway model using multiphase CFD analysis

    Science.gov (United States)

    Rajendran, Rahul; Banerjee, Arindam

    2015-11-01

    Mucus, a Bingham fluid is transported in the pulmonary airways by consistent beating of the cilia and exhibits a wide range of physical properties in response to the core air flow and various pathological conditions. A better understanding of the interfacial instability is required as it plays a crucial role in gas transport, mixing, mucus clearance and drug delivery. In the current study, mucus is modelled as a Newtonian fluid and the two phase gas-liquid flow in the airways is investigated using an inhomogeneous Eulerian-Eulerian approach. The complex interface between the phases is tracked using the conventional VOF (Volume of Fluid) method. Results from our CFD simulations which are performed in idealized single and double bifurcation geometries will be presented and the influence of airflow rate, mucus layer thickness, mucus viscosity, airway geometry (branching & diameter) and surface tension on mucus flow behavior will be discussed. Mean mucus layer thickness, pressure drop due to momentum transfer & increased airway resistance, mucus transport speed and the flow morphology will be compared to existing experimental and theoretical data.

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

    Directory of Open Access Journals (Sweden)

    Stellzig-Eisenhauer, Angelika

    2010-01-01

    Full Text Available 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.

  11. Dynamic testing of concrete under high confined pressure. Influence of saturation ratio and aggregate size

    Science.gov (United States)

    Forquin, P.; Piotrowska, E.; Gary, G.

    2015-09-01

    Concrete structures can be exposed to intense pressure loadings such as projectile-impact or detonation near a concrete structural element. To investigate the mechanical behaviour of concrete under high confining pressure, dynamic quasi-oedometric compression tests have been performed with a large diameter (80 mm) Split Hopkinson Pressure Bar apparatus. The concrete sample is placed within a steel confining ring and compressed along its axial direction. Hydrostatic pressures as high as 800 MPa and axial strain of about - 10% are reached during the tests. In the present work, experiments have been conducted on two types of concrete: MB50 microconcrete with a maximum grain size of 2 mm and R30A7 ordinary concrete of maximum grain size about 8 mm. Both concretes are tested in dry or saturated conditions. According to these dynamic experiments it is noted that grain size has a small influence whereas water content has a strong effect on the confined behaviour of concrete.

  12. The influence of back pressure on operation and blowdown of safety relief valves

    International Nuclear Information System (INIS)

    The article acquaints such researching procedure by the help of which the operating method of safety relief valve at back pressure is analysable and evaluable. There is a presentation of a new measuring apparatus supplied with electronic data processing device and computer on which at the safety relief valves the influence of the built-up and superimposed back pressure is examinable. The authors inform in the case of a selected valve type the correlations between the valve lift and the pressures acting on the valve. They analyse the relation between the flow force acting on the valve disc and the spring force. They introduce the relations among the discharge coefficient, the valve lift, and the back pressure. (orig.)

  13. How male sound pressure level influences phonotaxis in virgin female Jamaican field crickets (Gryllus assimilis

    Directory of Open Access Journals (Sweden)

    Karen Pacheco

    2014-06-01

    Full Text Available Understanding female mate preference is important for determining the strength and direction of sexual trait evolution. The sound pressure level (SPL acoustic signalers use is often an important predictor of mating success because higher sound pressure levels are detectable at greater distances. If females are more attracted to signals produced at higher sound pressure levels, then the potential fitness impacts of signalling at higher sound pressure levels should be elevated beyond what would be expected from detection distance alone. Here we manipulated the sound pressure level of cricket mate attraction signals to determine how female phonotaxis was influenced. We examined female phonotaxis using two common experimental methods: spherical treadmills and open arenas. Both methods showed similar results, with females exhibiting greatest phonotaxis towards loud sound pressure levels relative to the standard signal (69 vs. 60 dB SPL but showing reduced phonotaxis towards very loud sound pressure level signals relative to the standard (77 vs. 60 dB SPL. Reduced female phonotaxis towards supernormal stimuli may signify an acoustic startle response, an absence of other required sensory cues, or perceived increases in predation risk.

  14. 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.

  15. 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. PMID:26314989

  16. Experimental and computational investigations of surfactant physicochemical behavior during conditions emulating the opening of pulmonary airways

    Science.gov (United States)

    Ghadiali, Samir Nuruddin

    2000-10-01

    We have investigated the mechanical influence of surfactant physicochemical properties on the progression of a semi-infinite air bubble in a fluid filled rigid capillary. This system mimics the continual interfacial expansion dynamics that occur during the opening of collapsed pulmonary airways. The goal of this study is to ascertain the surfactant physicochemical properties that are responsible for reducing airway reopening pressures that may damage lung epithelial cells. To accomplish this goal, we have developed experimental and computational models of this system. The experimental model is used to measure the ability of various surfactants to alter the reopening pressure. The non-physiologic surfactant, SDS, is capable of reducing the interfacial stresses that elevate the reopening pressure, the main component of pulmonary surfactant, L-alpha-dipalmitoyl phosphatidylcholine (DPPC), exhibits large stresses, and the clinically relevant surfactant, Infasurf, reduces the reopening pressure but maintains a surface shear or Marangoni stress. Infasurf's behavior suggests that optimal surfactant properties will reduce the reopening pressures that may damage airway epithelial cells while maintaining the Marangoni stress that enhances airway stability. Analysis of the experimental data is based on a modification of previous theoretical models which can not simulate non-equilibrium conditions near the bubble tip. Therefore, we have developed a theoretical model of surfactant effects that is capable of simulating these non-equilibrium dynamics. The coupled governing equations for fluid mechanics, molecular transport, and interfacial dynamics, are solved using a combined boundary element, dual reciprocity boundary element, and finite difference scheme. Scaling of the governing equations yields dimensionless parameters that identify the relative importance of surfactant physicochemical properties. Independent parameter variation studies are used to investigate how individual

  17. Influence of high temperature on water content, permeability and pore pressures in concrete

    International Nuclear Information System (INIS)

    The influence of temperatures to 600degC on the performance of containment vessel concrete is studied in relation to pore pressures; moisture migration causing drying and physically saturated zones; and permeability for various types of cure and post-cure treatments. It is concluded that pore pressures to 10 MN/m2 can exist in non-uniformly heated concrete; water migration and driving take place rapidly during the first hour of heating; and permeability values may vary by more than seven orders of magnitude. (author)

  18. Blockage of upper airway

    Science.gov (United States)

    ... is made through the neck into the airway ( tracheostomy or cricothyrotomy). If the obstruction is due to ... team. Related MedlinePlus Health Topics Choking Throat Disorders Tracheal Disorders Browse the Encyclopedia A.D.A.M., Inc. ...

  19. Equine recurrent airway obstruction

    OpenAIRE

    Artur Niedźwiedź

    2014-01-01

    Equine Recurrent Airway Obstruction (RAO), also known as heaves or broken wind, is one of the most common disease in middle-aged horses. Inflammation of the airway is inducted by organic dust exposure. This disease is characterized by neutrophilic inflammation, bronchospasm, excessive mucus production and pathologic changes in the bronchiolar walls. Clinical signs are resolved in 3-4 weeks after environmental changes. Horses suffering from RAO are susceptible to allergens throughout their liv...

  20. Influence of sputtering gas pressure on properties of transparent conducting Si-doped zinc oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Hua; Liu, Hunfa; Lei, Chengxin [Shandong Univ. of Technology, Zibo (China). Dept. of Sciences

    2013-10-15

    Si-doped zinc oxide (SZO, Si 3%) thin films were deposited on glass substrates by means of direct current magnetron sputtering under different pressures. The influence of sputtering pressure on structure, morphology, optical and electrical properties of SZO thin films was investigated. The results reveal that the sputtering pressures have a significant impact on the growth rate, crystal quality and electrical properties of the films, but have little impact on the optical properties of the films. SZO thin film samples grown on glasses are polycrystalline with a hexagonal wurtzite structure and have a preferred orientation along the c-axis perpendicular to the substrate. When the sputtering pressure increases from 2 to 8 Pa, the film surface becomes compact and smooth, the degree of crystallization of the films increases, and the resistivity of films decreases. However, when the sputtering pressure continues to increase from 8 to 10 Pa, the degree of crystallization of the films decreases, the grain size decreases, and the resistivity of the films increases. SZO(3%) thin film deposited at a sputtering pressure of 8 Pa shows the largest carrier concentration, the largest mobility, the lowest resistivity of 3.0 x 10{sup -4} {Omega} cm and a high overall transmission of 93.3% in the visible range. (orig.)

  1. Influence of hydrostatic pressure on the thermal properties of polymers at low temperatures

    Science.gov (United States)

    Jäckel, Manfred; Weise, Frank; Opitz, Jörg; Geilenkeuser, Rolf

    The thermal conductivity λ of polycarbonate (PC) has been measured in the temperature range 3-150 K under hydrostatic pressure up to 1.3 GPa [Geilenkeuser, R., Weise, F. and Jäckel, M., Czech. J. Physics, 1996, 46, 2251 ( Proc. LT 21, Prag, August 1996)]. A strong influence of pressure on λ has been observed over the entire temperature range. Additional measurements of the pressure dependence of the density showed that the density of PC, polystyrene (PS), epoxy resin and PTFE (Teflon) increased considerably with pressure (Jäckel, M., Weise, F. and Geilenkeuser, R. In Proc. ICEC16/ICMC, Kitakyushu, May 1996, in press). At a pressure of 1.3 GPa the relative increase of the density amounts to 25%. The thermal conductivity data were corrected for the changes of density, sample geometry and sound velocity. The corrected data show an increase of λ with pressure only in the plateau region of thermal conductivity. Similar results were measured for vitreous silica (Jäckel, M., Wagner, K. and Hegenbarth, E., Physica B, 1996, 219&220, 308) and epoxy resin (Grace, J.M. and Anderson, A.C., Phys. Rev. B, 1989, 40, 1901).

  2. Influence of the Pressure Difference and Door Swing on Heavy Contaminants Migration between Rooms.

    Directory of Open Access Journals (Sweden)

    Jacek Hendiger

    Full Text Available This paper presents the results of investigations whose aim was to describe the influence of the pressure difference level on the ability of contaminants migration between neighbouring rooms in dynamic conditions associated with door swing. The analysis was based on airflow visualization made with cold smoke, which simulated the heavy contaminants. The test room was pressurized to a specific level and then the door was opened to observe the trail of the smoke plume in the plane of the door. The door was opened in both directions: to the positively and negatively pressurized room. This study focuses on the visualization of smoke plume discharge and an uncertainty analysis is not applicable. Unlike other studies which focus on the analysis of pressure difference, the present study looks at the contaminants which are heavier than air and on "pumping out" the contaminants by means of door swing. Setting the proper level of pressure difference between the contaminated room and the neighbouring rooms can prove instrumental in ensuring protection against toxic contaminants migration. This study helped to establish the threshold of pressure difference necessary to reduce migration of heavy contaminants to neighbouring rooms.

  3. Influence of the Pressure Difference and Door Swing on Heavy Contaminants Migration between Rooms

    Science.gov (United States)

    Hendiger, Jacek; Chludzińska, Marta; Ziętek, Piotr

    2016-01-01

    This paper presents the results of investigations whose aim was to describe the influence of the pressure difference level on the ability of contaminants migration between neighbouring rooms in dynamic conditions associated with door swing. The analysis was based on airflow visualization made with cold smoke, which simulated the heavy contaminants. The test room was pressurized to a specific level and then the door was opened to observe the trail of the smoke plume in the plane of the door. The door was opened in both directions: to the positively and negatively pressurized room. This study focuses on the visualization of smoke plume discharge and an uncertainty analysis is not applicable. Unlike other studies which focus on the analysis of pressure difference, the present study looks at the contaminants which are heavier than air and on “pumping out” the contaminants by means of door swing. Setting the proper level of pressure difference between the contaminated room and the neighbouring rooms can prove instrumental in ensuring protection against toxic contaminants migration. This study helped to establish the threshold of pressure difference necessary to reduce migration of heavy contaminants to neighbouring rooms. PMID:27171260

  4. 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.

  5. FEM Simulation of Influence of Protective Encapsulation on MEMS Pressure Sensor

    DEFF Research Database (Denmark)

    Yao, Qingshan; Janting, Jakob; Branebjerg, Jens

    2003-01-01

    to the substrate. Thermal related conclusion remarks:• For the currently selected polymer encapsulation material with a thermal expansion coefficient of 5·10-5, the temperature-induced deformation has significant influence on the sensitivity. A temperature change of 15 °C will give a signal as a pressure of 40...... compared to the conventionally exposed sensor. 2) Stress concentration calculations are performed to investigate if the encapsulation could lead to increased stress concentration in the silicon structure. The reliability of the adhesion of the metallic encapsulating membrane is assessed by investigating...... whether the metallic membrane / coating will peel off when applying the maximum pressure, which is 4000 bar leading to high shear stress between the metallic membrane and the polymer encapsulation material.3) Thermal calculations are made to evaluate the influence of the environment on the packaged sensor...

  6. 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...

  7. Effect of continuous positive airway pressure on fluid absorption among patients with pleural effusion due to tuberculosis Efeito da pressão positiva nas vias aéreas sobre a absorção do derrame pleural em pacientes devido à tuberculose

    OpenAIRE

    Juliana F. Oliveira; Mello, Fernanda C. Q.; Rosana S. Rodrigues; Ana L. Boechat; Conde, Marcus B.; Sara L. S. Menezes

    2010-01-01

    BACKGROUND: Tuberculosis (TB) remains as an important public health problem worldwide. The most common type is pulmonary TB, and the most prevalent form of extra-pulmonary disease among HIV-negative patients is pleural disease. OBJECTIVE: The objective of the present study was to determine the effect of continuous positive airway pressure (CPAP) on fluid absorption among patients with pleural effusion due to TB. METHODS: Twenty patients were randomized into two groups. The interventional grou...

  8. 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...

  9. Influence of the pressure holding time on strain generation in fuel injection lines

    Energy Technology Data Exchange (ETDEWEB)

    Basara, Adis, E-mail: adis.basara@evonik.com [Process Technology and Engineering, Evonik Degussa GmbH, Rodenbacher Chaussee 4, 63457 Hanau-Wolfgang (Germany); Alt, Nicolas; Schluecker, Eberhard [Institute for Process Technology and Machinery, Friedrich-Alexander University Erlangen-Nuremberg, Cauerstrasse 4, 91058 Erlangen (Germany)

    2011-04-15

    An influence of the pressure holding time on residual strain generation during the autofrettage process was studied experimentally for the first time in the present work. It is the state of the art that fuel injection lines are held at the autofrettage pressure for only a few seconds in an industrial production. In doing so, it is assumed that a desirable residual stress-strain pattern is generated. However, the results of the experimental investigations outlined in this work indicated that completion of the plastic deformation caused by the autofrettage process and generation of the desirable stress-strain pattern require a much longer period. As shown, a third-order polynomial equation best described the interdependence between the time required for the completion of the process, the corresponding autofrettage pressure and the generated strain state. The method presented can be used as a tool for the determination of the optimal autofrettage process parameters in industrial production of fuel injection lines.

  10. 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.

  11. Influence of stimulus frequency, amplitude and blood pressure on signal change in fMRI

    International Nuclear Information System (INIS)

    Purpose: To examine the influence of frequency and amplitude of a stimulus and the effect of blood pressure on signal intensity changes in functional MRI. Methods: Somatosensory stimulation of five (normotonic/hypotonic) anesthetized rats was performed with different stimulus frequencies and amplitudes. Measurements were performed with a 2.4 Tesla experimental scanner using a gradient-echo (GE) echo-planar imaging (EPI) sequence. Results: The highest signal change was found at a frequency of 3 Hz and a stimulation amplitude of ten times the threshold value. A decrease of blood pressure to half the normotonic value gave rise to a decrease of the neuronal response of about 17%. Conclusion: Optimization of the stimulation frequency and stimulation amplitude maximizes signal changes in functional MRI of the somatosensory cortex. Even with a standardized paradigm, variations in measured neuronal activity may occur when blood pressure changes cannot be compensated by autoregulation. (orig.)

  12. Influence of belt speed, grit sizes and pressure on the sanding of Eucalyptus grandis wood

    OpenAIRE

    Alexandre Jorge Duarte de Souza; Luis Fernando Frezzatti Santiago; Marcos Tadeu Tiburcio Gonçalves; Manoel Cléber de Sampaio Alves; Francisco Mateus Faria de Almeida Varasquim

    2012-01-01

    The sanding process is important to the quality of wood products. Sanding reduces imperfections in wood surfaces and it is important to the final product and application of paints or varnishes. There are few studies about sanding in the literature and finding out the relationship between the input parameters (i.e., species of wood, grit size, abrasive) on the output parameters (i.e., roughness, force, pressure) will help to improve this process. This study analyzed the influence of input para...

  13. Influences of brain tissue poroelastic constants on intracranial pressure (ICP) during constant-rate infusion.

    Science.gov (United States)

    Li, Xiaogai; von Holst, Hans; Kleiven, Svein

    2013-01-01

    A 3D finite element (FE) model has been developed to study the mean intracranial pressure (ICP) response during constant-rate infusion using linear poroelasticity. Due to the uncertainties in the poroelastic constants for brain tissue, the influence of each of the main parameters on the transient ICP infusion curve was studied. As a prerequisite for transient analysis, steady-state simulations were performed first. The simulated steady-state pressure distribution in the brain tissue for a normal cerebrospinal fluid (CSF) circulation system showed good correlation with experiments from the literature. Furthermore, steady-state ICP closely followed the infusion experiments at different infusion rates. The verified steady-state models then served as a baseline for the subsequent transient models. For transient analysis, the simulated ICP shows a similar tendency to that found in the experiments, however, different values of the poroelastic constants have a significant effect on the infusion curve. The influence of the main poroelastic parameters including the Biot coefficient α, Skempton coefficient B, drained Young's modulus E, Poisson's ratio ν, permeability κ, CSF absorption conductance C(b) and external venous pressure p(b) was studied to investigate the influence on the pressure response. It was found that the value of the specific storage term S(ε) is the dominant factor that influences the infusion curve, and the drained Young's modulus E was identified as the dominant parameter second to S(ε). Based on the simulated infusion curves from the FE model, artificial neural network (ANN) was used to find an optimised parameter set that best fit the experimental curve. The infusion curves from both the FE simulation and using ANN confirmed the limitation of linear poroelasticity in modelling the transient constant-rate infusion. PMID:22452461

  14. The Influence of Hatha Yoga Exercise on Arterial Pressure and Pulse

    OpenAIRE

    Piekorz, Zuzanna; Bułatowicz, Irena; Radzimińska, Agnieszka; Lewandowski, Andrzej; Piekorz, Szymon; Grabarczyk, Grzegorz; Ciesielska, Monika

    2013-01-01

    Introduction. Hypertension constitutes a great problem in modern medicine. Due to it being widespread in the society, it seems justified to introduce complex treatment and prevent from this disease. Hypotensive qualities of yoga exercise described in literature constitute an interest as an alternative form of cardiological rehabilitation. Material and methods. In order to evaluate its influence on the values of blood pressure and pulse, a group of people attending hatha yoga classes was studi...

  15. Influence of the yaw angle on heat transfer and pressure drop of helical type heat exchangers

    International Nuclear Information System (INIS)

    The influence of the flow angle φ between the tube axis and the flow direction on heat transfer and pressure drop has been studied at 15 deg. ≤ φ ≤ 90 deg. (cross flow). The Reynolds number was varied in the range 2.103 ≤ Re ≤ 105. Experimental data are given for a number of tube banks of straight tubes as well as a helical type heat exchanger with a large thread pitch of the tubes. (author)

  16. Influence of Attachment Pressure and Kinematic Configuration on pHRI with Wearable Robots

    OpenAIRE

    André Schiele; van der Helm, Frans C. T.

    2009-01-01

    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...

  17. Destructive attraction: factors that influence hunting pressure on the Blue Bird-of-paradise Paradisaea rudolphi

    OpenAIRE

    Bergh, van den, H.; Kusters, Koen; Dietz, A.J.

    2013-01-01

    The Blue Bird-of-paradise Paradisaea rudolphi (BBOP) is a globally threatened species restricted to the montane rainforest of Papua New Guinea (PNG). Local inhabitants hunt the BBOP for its feathers, which is one of the main reasons for its population decline. The feathers are used for both traditional and commercial purposes. So far virtually nothing is known about which factors enhance or decrease hunting pressure, and how this is influenced by ongoing market integration of local communitie...

  18. 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...

  19. Therapeutic effect of nasal continuous positive airway pressure ventilation on treatment of neonates with severe respiratory disease and hypoxaemia%鼻塞持续气道正压通气治疗新生儿危重呼吸病低氧血症的效果观察

    Institute of Scientific and Technical Information of China (English)

    张磊; 公静; 张丽微

    2015-01-01

    Objective To explore the effect of nasal continuous positive airway pressure ventilation on severe respiratory disease and hypoxaemia. Methods In 30 neonates with severe respiratory disease-induced hypoxemia were managed with nasal continuous positive airway pressure, and corresponding nursing. Nasal continuous positive airway pressure before and after treatment, 24h arterial partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (PCO2), PaO2/FiO2 and pH value in children were observed. Result After nasal continuous positive airway pressure ventilation, the levels of PaO2, post-PCO2, PaO2/FiO2 and pH value of children were better than the positive pressure ventilation before treatment and positive pressure ventilation (P < 0.05). Conclusions Nasal continuous positive airway pressure ventilation has good therapeutic effect on severe respiratory disease in children with neonatal hypoxemia. Good ventilation pressure regulation, skin and mucosa protection, prevention of vomiting in children with nursing to ensure the positive significance of continuous positive airway pressure therapy.%目的:了解鼻塞持续气道正压通气治疗新生儿危重呼吸病低氧血症的效果,并总结其护理经验。方法对30例危重呼吸病低氧血症新生儿采用鼻塞持续气道正压通气治疗,并实施相应的护理。观察鼻塞持续气道正压通气治疗前和治疗24 h后患儿动脉血氧分压(arterial partial pressure of oxygen,PaO2),二氧化碳分压(partial pressure of carbon dioxide,PCO2),氧合指数(carterial oxygen tension, PaO2/FiO2)和pH值。结果鼻塞持续气道正压通气治疗后新生儿PaO2、PCO2、PaO2/FiO2和pH值均优于正压通气治疗前,治疗前后比较,差异均有统计学意义(P<0.05)。结论鼻塞持续气道正压通气对新生儿危重呼吸病低氧血症具有良好的治疗效果。做好通气压力调节,新生儿鼻部皮肤及黏膜的保护,预

  20. 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. PMID:8730520

  1. Influence of decontamination of the WWER-440 primary circuit equipment on pressure drop in the reactor

    International Nuclear Information System (INIS)

    Over 40 reactor cycles at four WWER-440 type reactors have been analyzed in order to explain the increase of the pressure drop under certain combination of conditions. It is shown that the staff radiation exposure and the dose rate at first circuit segments are inversely correlated with the value of the pressure drop at the reactor, which is connected with the mechanism of redistribution of deposits and radioactive nuclides between the reactor and the rest part of the circuit. The influence of pHT on the formation of the dose rate from equipment and the change of pressure drop in the reactor WWER-440 is studied. The optimal range of pHT values for these parameters is determined to be 6.95-7.05 and these values are within the range of the water chemistry standards. The correlation between the changes of pressure drop and the number of decontaminated steam generators is established. This correlation shows that the pressure drop at the reactor grows with the increase of steam generators decontaminated during a preventive maintenance

  2. Influence of oxygen partial pressure on the properties of pulsed laser deposited nanocrystalline zirconia thin films

    International Nuclear Information System (INIS)

    ZrO2 thin films were deposited at various oxygen partial pressures (2.0 x 10-5-3.5 x 10-1 mbar) at 973 K on (1 0 0) silicon and quartz substrates by pulsed laser deposition. The influence of oxygen partial pressure on structure, surface morphology and optical properties of the films were investigated. X-ray diffraction results indicated that the films are polycrystalline containing both monoclinic and tetragonal phases. The films prepared in the oxygen partial pressures range 2.0 x 10-5-3.5 x 10-1 mbar contain nanocrystals of sizes in the range 54-31 nm for tetragonal phase. The peak intensity of the tetragonal phase decreases with the increase of oxygen partial pressures. Surface morphology of the films examined by AFM shows the formation of nanostructures. The RMS surface roughness of the film prepared at 2.0 x 10-5 mbar is 1.3 nm while it is 3.2 nm at 3.5 x 10-1 mbar. The optical properties of the films were investigated using UV-visible spectroscopy technique in the wavelength range of 200-800 nm. The refractive index is found to decrease from 2.26 to 1.87 as the oxygen partial pressure increases from 2.0 x 10-5 to 3.5 x 10-1 mbar. The optical studies show two different absorption edges corresponding to monoclinic and tetragonal phases.

  3. Influence of the Oxygen Partial Pressure on the Oxidation of Inconel 617 Alloy at High Temperature

    International Nuclear Information System (INIS)

    Ni-based superalloy Inconel 617 (IN617) is one of the main candidate structural materials for high temperature components (heat exchanger) of the gas-cooled fast reactor (GFR), a possible candidate for generation IV nuclear reactor. The material in operating conditions will be exposed to impure He at a temperature of around 850 C. The impurities are expected to be oxidizing (such as O2, H2O) but since no feedback experience is available for this type of reactor, the level of impurities is completely unknown. Hence, an attempt has been made to understand the influence of oxygen partial pressure on oxide composition and on the oxidation mechanisms of IN617 at 850 C. To achieve this, oxidation tests were performed at 3 different range of partial pressure: 10-5, 0. 2 and 200 mbar. Tests were performed from 1 h to 28 days and the obtained oxide layers were characterized using MEB, EDX, XPS, XRD and GD-OES. The oxide layers were mainly composed of chromia containing TiO2 and thickening with time. Aluminium oxide formed internally. Other oxides were detected in the scale, such as NiO, CoO, MoO3 and MnO2, except for the lowest oxygen partial pressure experiments, where a selective oxidation took place. The scale-growth mechanism was cationic for low and medium oxygen partial pressure conditions. A growth following a transient oxidation mechanism was observed for high oxygen partial pressure. (authors)

  4. [The Influence of Deposition Pressure on the Properties of Hydrogenated Amorphous Silicon Thin Films].

    Science.gov (United States)

    Yuan, Jun-bao; Yang, Wen; Chen, Xiao-bo; Yang, Pei-zhi; Song, Zhao-ning

    2016-02-01

    Hydrogenated amorphous silicon (a-Si:H) thin films on soda-lime glass substrates were deposited by plasma enhanced chemical vapor deposition (PECVD) using disilane and hydrogen as source gases. To study the influence of deposition pressure on the deposition rate, optical band gap and structure factor, a surface profilometer, an ultraviolet-visible spectrometer, a Fourier transform infrared (FTIR) spectrometer and a scanning electron microscopy (SEM) were used to characterize the deposited thin films. It is found that the deposition rate firstly increased and then decreased and the optical band gap monotonically decreased with the increasing deposition pressure. Moreover, the formation of SiH bond was preferable to the formation of SH₂ or SiH₃ bond when the deposition pressure was less than 210 Pa, while it was opposite when the deposition pressure is higher than 210 Pa. Finally, the deposition pressure in the range of 110~210 Pa was found to be more suitable for the preparation of high quality a-Si:H thin films. PMID:27209724

  5. 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......, neutrophil airway inflammation increases airway closure during bronchoconstriction, while eosinophil airway inflammation increases airway hyperresponsiveness (AHR). METHODS: Asthmatic subjects (n = 26), aged ≥55 years (68% female), were studied, and AHR to 4.5% saline challenge was measured by the response......-dose ratio (%fall in forced expiratory volume in 1 s (FEV1 )/mg saline). Airway closure was assessed during bronchoconstriction percent change in forced vital capacity (FVC)/percent change in FEV1 (i.e. Closing Index). Airway inflammation was assessed by induced sputum and exhaled nitric oxide (eNO). RESULTS...

  6. Role of upper airway ultrasound in airway management.

    Science.gov (United States)

    Osman, Adi; Sum, Kok Meng

    2016-01-01

    Upper airway ultrasound is a valuable, non-invasive, simple, and portable point of care ultrasound (POCUS) for evaluation of airway management even in anatomy distorted by pathology or trauma. Ultrasound enables us to identify important sonoanatomy of the upper airway such as thyroid cartilage, epiglottis, cricoid cartilage, cricothyroid membrane, tracheal cartilages, and esophagus. Understanding this applied sonoanatomy facilitates clinician to use ultrasound in assessment of airway anatomy for difficult intubation, ETT and LMA placement and depth, assessment of airway size, ultrasound-guided invasive procedures such as percutaneous needle cricothyroidotomy and tracheostomy, prediction of postextubation stridor and left double-lumen bronchial tube size, and detecting upper airway pathologies. Widespread POCUS awareness, better technological advancements, portability, and availability of ultrasound in most critical areas facilitate upper airway ultrasound to become the potential first-line non-invasive airway assessment tool in the future. PMID:27529028

  7. The Influence of Pressure on the Intrinsic Dissolution Rate of Amorphous Indomethacin

    Directory of Open Access Journals (Sweden)

    Korbinian Löbmann

    2014-08-01

    Full Text Available New drug candidates increasingly tend to be poorly water soluble. One approach to increase their solubility is to convert the crystalline form of a drug into the amorphous form. Intrinsic dissolution testing is an efficient standard method to determine the intrinsic dissolution rate (IDR of a drug and to test the potential dissolution advantage of the amorphous form. However, neither the United States Pharmacopeia (USP nor the European Pharmacopeia (Ph.Eur state specific limitations for the compression pressure in order to obtain compacts for the IDR determination. In this study, the influence 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 visually observed to study the effects of compaction pressure on their surface properties. It was found that there is no significant correlation between IDR and compression pressure for crystalline IND and IND–PVP. This was in line with the observation of similar surface properties of the compacts. However, 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 of the amorphous form might be underestimated. It is thus suggested that for a reasonable interpretation of the IDR, surface properties of the different analyzed samples should be investigated and for amorphous samples the IDR should be measured also as a function of the compression pressure used to prepare the solid sample for IDR testing.

  8. 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

  9. Upper airway radiographs in infants with upper airway insufficiency.

    OpenAIRE

    Tonkin, S L; Davis, S.L.; Gunn, T R

    1994-01-01

    Upper airway measurements in nine infants considered to be at risk of upper airway insufficiency, six of whom presented after an apnoeic episode, were compared with measurements taken in two age groups of healthy infants. Paired, inspiratory and expiratory, lateral upper airway radiographs were obtained while the infants were awake and breathing quietly. The radiographs of all nine infants demonstrated narrowing in the oropharyngeal portion of the airway during inspiration and in six infants ...

  10. 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.

  11. 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

  12. On the correlation of buoyancy-influenced turbulent convective heat transfer to fluids at supercritical pressure

    International Nuclear Information System (INIS)

    This paper is concerned with buoyancy-influenced turbulent convective heat transfer in vertical tubes for conditions where the physical properties vary strongly with temperature as in fluids at supercritical pressure in the pseudocritical temperature region. An extended physically-based, semi-empirical model is described which has been developed to account for the extreme non-uniformity of properties which can be present in such fluids and lead to strong influences of buoyancy which cause the mean flow and turbulence fields to be modified in such a manner that has a very profound effect on heat transfer. Data for both upward and downward flow from experiments using carbon dioxide at supercritical pressure (8.80, MPa, p/pc=1.19) in a uniformly heated tube of internal diameter 2 mm and length 290 mm, obtained under conditions of strong non-uniformity of fluid properties, are being correlated and fitted using an approach based on the model. It provides a framework for describing the complex heat transfer behaviour which can be encountered in such experiments by means of an equation of simple form. Buoyancy-induced impairment and enhancement of heat transfer is successfully reproduced by the model. Similar studies are in progress using experimental data for both carbon dioxide and water from other sources. The aim is to obtain an in-depth understanding of the mechanisms by which deterioration of heat transfer might arise in sensitive applications involving supercritical pressure fluids, such as high pressure, water-cooled reactors operating above the critical pressure. (authors)

  13. On the correlation of buoyancy-influenced turbulent convective heat transfer to fluids at supercritical pressure

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, J. D. [Univ. of Manchester, Manchester (United Kingdom); Jiang, P. X.; Liu, B. [Tsinghua Univ., Thermal Engineering Dept., Beijing (China)

    2012-07-01

    This paper is concerned with buoyancy-influenced turbulent convective heat transfer in vertical tubes for conditions where the physical properties vary strongly with temperature as in fluids at supercritical pressure in the pseudocritical temperature region. An extended physically-based, semi-empirical model is described which has been developed to account for the extreme non-uniformity of properties which can be present in such fluids and lead to strong influences of buoyancy which cause the mean flow and turbulence fields to be modified in such a manner that has a very profound effect on heat transfer. Data for both upward and downward flow from experiments using carbon dioxide at supercritical pressure (8.80, MPa, p/pc=1.19) in a uniformly heated tube of internal diameter 2 mm and length 290 mm, obtained under conditions of strong non-uniformity of fluid properties, are being correlated and fitted using an approach based on the model. It provides a framework for describing the complex heat transfer behaviour which can be encountered in such experiments by means of an equation of simple form. Buoyancy-induced impairment and enhancement of heat transfer is successfully reproduced by the model. Similar studies are in progress using experimental data for both carbon dioxide and water from other sources. The aim is to obtain an in-depth understanding of the mechanisms by which deterioration of heat transfer might arise in sensitive applications involving supercritical pressure fluids, such as high pressure, water-cooled reactors operating above the critical pressure. (authors)

  14. Influence of pore pressure on the successive failures of intact slopes

    Science.gov (United States)

    Voulgari, Chrysoula; Utili, Stefano

    2016-04-01

    The presence of water can significantly change the stability of a slope and as a result the evolution of a slope in time. In this paper the influence of pore water pressure on the morphological evolution of natural cliffs subject to progressive retreat is investigated. The upper bound theorem of limit analysis is employed to evaluate the stability number and the failure mechanism of successive failures of uniform c, φ slopes with the presence of water. This model extends the existing analytical framework on the evolution of slopes subjected to weathering by accounting for the presence of water. Pore-water pressure is considered in the model by using the coefficient ru, a description of the pore-water pressure distribution that is approximate, but is commonly used in slope stability analyses. To account for the influence of the pore pressure, the work of pore-water pressure on the deformation of the soil along the failure surface had to be included in the model leading to modified analytical expressions of the energy balance equation (the balance between external work and dissipated energy) and as a consequence, of the function whose minimum provides the solution in terms of failure mechanisms and associated values of soil strength. With this model it is possible to relate the evolution of natural slopes with the presence of water by a sequence of rotational sliding block failures to the degradation of material strength properties. Computations were carried out for a wide range of parameters (friction angle φ and initial slope inclination β) and a set of normalized solutions is presented for different values of ru coefficient.

  15. 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 and will...

  16. Intraoperative endobronchial rupture of pulmonary hydatid cyst: An airway catastrophe

    Directory of Open Access Journals (Sweden)

    Richa Gupta

    2013-01-01

    Full Text Available Hydatid cyst disease of lungs may not be symptomatic. It may present as spontaneous rupture in pleura or a bronchus. During spontaneous breathing, cyst content of endobronchially ruptured pulmonary hydatid cyst is mostly evacuated by coughing. However, during positive pressure ventilation such extruded fragments may lodge into smaller airway leading to an airway catastrophe. We present such accidental endobronchial rupture of pulmonary hydatid cyst during surgery, its prompt detection, and management by rigid bronchoscopy.

  17. Influence of crack depth on the fracture toughness of reactor pressure vessel steel

    International Nuclear Information System (INIS)

    The Heavy Section Steel Technology Program (HSST) at Oak Ridge National Laboratory (ORNL) is investigating the influence of flaw depth on the fracture toughness of reactor pressure vessel (RPV) steel. Recently, it has been shown that, in notched beam testing, shallow cracks tend to exhibit an elevated toughness as a result of a loss of constraint at the crack tip. The loss of constraint takes place when interaction occurs between the elastic-plastic crack-tip stress field and the specimen surface nearest the crack tip. An increased shallow-crack fracture toughness is of interest to the nuclear industry because probabilistic fracture-mechanics evaluations show that shallow flaws play a dominant role in the probability of vessel failure during postulated pressurized-thermal-shock (PTS) events. Tests have been performed on beam specimens loaded in 3-point bending using unirradiated reactor pressure vessel material (A533 B). Testing has been conducted using specimens with a constant beam depth (W = 94 mm) and within the lower transition region of the toughness curve for A533 B. Test results indicate a significantly higher fracture toughness associated with the shallow flaw specimens compared to the fracture toughness determined using deep-crack (a/W = 0.5) specimens. Test data also show little influence of thickness on the fracture toughness for the current test temperature (-60 degree C). 21 refs., 5 figs., 3 tabs

  18. Experimental evidence of imperfection influence on the buckling of thin cylindrical shell under uniform external pressure

    International Nuclear Information System (INIS)

    The load carrying behaviour of cylindrical thin-walled shell structures under pressure load is strongly dependent on the nature and magnitude of the imperfections invariably caused by various manufacturing processes. The present paper examines instabilities of long homogeneous and isotropic thin elastic tubes, characterized by geometric imperfections like eccentricity or oval shape, on the buckling behaviour in conditions for which, at present, a complete theoretical analysis was not found in literature. Moreover, the additional aspect of the influence of the welded joint geometry and position is investigated over a wide range of diameter to thickness ratio, extending the findings of previous works. The experiments were conducted on test specimens with different materials, e.g. A-316 ASTM (with and without seam weld) and Inconel, as well as different loading conditions (lateral and hydrostatic external pressure). A validation of numerical evaluations by comparison with test results is also performed. A good agreement has been observed between the experimental data and the elasto-plastic finite element analyses results, highlighting also the different influence of the mentioned imperfections on the buckling loads. For all 3 tube families tested, the oval form was found to reduce the collapse pressure quite significantly. The local thickness variation along the longitudinal welding and the interaction between neighbouring imperfections have been shown to be important factors governing buckling

  19. 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.

  20. NCPAP联合PS治疗早产儿肺透明膜病的临床效果研究%Effect of nasal continuous positive airway pressure and pulmonary surfactant on hyaline membrane disease in premuture infant

    Institute of Scientific and Technical Information of China (English)

    郑莉

    2013-01-01

    Objective To discuss the clinical effects of nasal continuous positive airway pressure and pulmonary surfactant on hyaline membrane disease in premuture infant. Methods 108 premature infant with hyaline membrane disease were selected from Janauary 2010 to March 2013 in our hospital. And they were randomly divided into three group,A group were received NCPAP and PS , B group were just received NCPAP,C group were only recived PS.Breath,heart rate,blood pressure and blood gas were analyzed. Results Premature infants in all groups showed significantly therapeutically effect on breath,heart rate,blood pressure and blood gas analysis after therapy(P<0.05). While premature infants in A group showed significantly therapeutically effect on breath, heart rate,PaO2, PaCO2 and SaO2 than other groups(P < 0.05). Conclusion NCPAP and PS presented significant therapeutically effect,and improved life quality and reduce adverse effect,which should be worth to extend in clinical.%  目的探讨NCPAP联合PS治疗早产儿肺透明膜病的临床效果。方法收集我院2010年1月~2013年3月治疗的肺透明膜病早产儿108例,随机分为三组,A组给予鼻塞持续气道正压通气(NCPAP)、肺表明活性物质(PS)治疗,B组给予NCPAP治疗,C组给予肺表面活性物质(PS)治疗。观察各组患儿治疗前后呼吸、心率、血压及血气分析等。结果各组患儿治疗后的呼吸、心率、PaO2均与治疗前比较,差异有统计学意义(P<0.05)。其中A组患儿治疗后呼吸、心率及PaO2、PaCO2、SaO2与C组治疗后比较,差异有统计学意义(P<0.05)。结论NCPAP联合PS具有较好的临床治疗效果,提高患儿生存质量,减少不良反应的发生,值得临床广泛推广。

  1. What does airway resistance tell us about lung function?

    Science.gov (United States)

    Kaminsky, David A

    2012-01-01

    Spirometry is considered the primary method to detect the air flow limitation associated with obstructive lung disease. However, air flow limitation is the end-result of many factors that contribute to obstructive lung disease. One of these factors is increased airway resistance. Airway resistance is traditionally measured by relating air flow and driving pressure using body plethysmography, thus deriving airway resistance (R(aw)), specific airway resistance (sR(aw)), and specific airway conductance (sG(aw)). Other methods to measure airway resistance include the forced oscillation technique (FOT), which allows calculation of respiratory system resistance (R(RS)) and reactance (X(RS)), and the interrupter technique, which allows calculation of interrupter resistance (R(int)). An advantage of these other methods is that they may be easier to perform than spirometry, making them particularly suited to patients who cannot perform spirometry, such as young children, patients with neuromuscular disorders, or patients on mechanical ventilation. Since spirometry also requires a deep inhalation, which can alter airway resistance, these alternative methods may provide more sensitive measures of airway resistance. Furthermore, the FOT provides unique information about lung mechanics that is not available from analysis using spirometry, body plethysmography, or the interrupter technique. However, it is unclear whether any of these measures of airway resistance contribute clinically important information to the traditional measures derived from spirometry (FEV(1), FVC, and FEV(1)/FVC). The purpose of this paper is to review the physiology and methodology of these measures of airway resistance, and then focus on their clinical utility in relation to each other and to spirometry. PMID:22222128

  2. Equine recurrent airway obstruction

    Directory of Open Access Journals (Sweden)

    Artur Niedźwiedź

    2014-10-01

    Full Text Available Equine Recurrent Airway Obstruction (RAO, also known as heaves or broken wind, is one of the most common disease in middle-aged horses. Inflammation of the airway is inducted by organic dust exposure. This disease is characterized by neutrophilic inflammation, bronchospasm, excessive mucus production and pathologic changes in the bronchiolar walls. Clinical signs are resolved in 3-4 weeks after environmental changes. Horses suffering from RAO are susceptible to allergens throughout their lives, therefore they should be properly managed. In therapy the most importanthing is to eliminate dustexposure, administration of corticosteroids and use bronchodilators to improve pulmonary function.

  3. Influence of pressure and silane depletion on microcrystalline silicon material quality and solar cell performance

    International Nuclear Information System (INIS)

    Hydrogenated microcrystalline silicon growth by very high frequency plasma-enhanced chemical vapor deposition is investigated in an industrial-type parallel plate R and D KAI reactor to study the influence of pressure and silane depletion on material quality. Single junction solar cells with intrinsic layers prepared at high pressures and in high silane depletion conditions exhibit remarkable improvements, reaching 8.2% efficiency. Further analyses show that better cell performances are linked to a significant reduction of the bulk defect density in intrinsic layers. These results can be partly attributed to lower ion bombardment energies due to higher pressures and silane depletion conditions, improving the microcrystalline material quality. Layer amorphization with increasing power density is observed at low pressure and in low silane depletion conditions. A simple model for the average ion energy shows that ion energy estimates are consistent with the amorphization process observed experimentally. Finally, the material quality of a novel regime for high rate deposition is reviewed on the basis of these findings

  4. Dynamic testing of concrete under high confined pressure. Influence of saturation ratio and aggregate size

    Directory of Open Access Journals (Sweden)

    Forquin P.

    2015-01-01

    Full Text Available Concrete structures can be exposed to intense pressure loadings such as projectile-impact or detonation near a concrete structural element. To investigate the mechanical behaviour of concrete under high confining pressure, dynamic quasi-oedometric compression tests have been performed with a large diameter (80 mm Split Hopkinson Pressure Bar apparatus. The concrete sample is placed within a steel confining ring and compressed along its axial direction. Hydrostatic pressures as high as 800 MPa and axial strain of about − 10% are reached during the tests. In the present work, experiments have been conducted on two types of concrete: MB50 microconcrete with a maximum grain size of 2 mm and R30A7 ordinary concrete of maximum grain size about 8 mm. Both concretes are tested in dry or saturated conditions. According to these dynamic experiments it is noted that grain size has a small influence whereas water content has a strong effect on the confined behaviour of concrete.

  5. 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.

  6. Chemical vapour deposition of praseodymium oxide films on silicon: influence of temperature and oxygen pressure

    International Nuclear Information System (INIS)

    Metal-organic chemical vapour deposition (MOCVD) of various phases in PrOx system has been studied in relation with deposition temperature (450-750 deg. C) and oxygen partial pressure (0.027-100 Pa or 0.2-750 mTorr). Depositions were carried out by pulsed liquid injection MOCVD using Pr(thd)3 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) precursor dissolved in toluene or monoglyme. By varying deposition temperature and oxygen partial pressure amorphous films or various crystalline PrOx phases (Pr2O3, Pr7O12, Pr6O11) and their mixtures can be grown. The pure crystalline Pr2O3 phase grows only in a narrow range of partial oxygen pressure and temperature, while high oxygen pressure (40-100 Pa) always leads to the most stable Pr6O11 phase. The influence of annealing under vacuum at 750 deg. C on film phase composition was also studied. Near 90% step coverage conformity was achieved for PrOx films on structured silicon substrates with aspect ratio 1:10. In air degradation of Pr2O3 films with transformation to Pr(OH)3 was observed in contrast to Pr6O11 films

  7. The influence of chemical composition on the saturated vapor pressure in biological motor fuels

    Directory of Open Access Journals (Sweden)

    Є.В. Полункін

    2010-01-01

    Full Text Available  Volatility fuels fraction of the estimated parameters and letkosti. Volatility characterizes the ability to switch fuels in vaporous state. Selecting indicators to assess the volatility depends on the chemical composition of fuel. The main measure letkosti etanolnogo fuel is vapor pressure. The most simple and cost-effective to improve cold start is putting in fuel lehkoletyuchyh components: butane, izopentanu, gas and other petroleum. It was investigated the influence of DEE on alcohol-gasoline blend, the results show that DEE positive impact on increasing vapor pressure to the desired minimum for starting the engine. But because the ether to 19%, then at such high levels can actively formed peroxide compounds, which is undesirable. Very promising is the use of propane-butane gas mixture as lehkoletyuchoyi gaseous component. Butanizovani spirit-petrol mixture can be recommended for use as alternative fuel vehicles after further study of their stability and himmotolohichnyh characteristics.

  8. 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.

  9. Dark current measurements in humid SF6: influence of electrode roughness, relative humidity and pressure

    International Nuclear Information System (INIS)

    The measurement of ‘dark current’ in pressurized SF6 at high electric field is performed using electrodes with a coaxial geometry. To identify the main mechanisms involved in measured currents, the influences of electrode roughness, gas pressure and relative humidity have been investigated. The experimental results reveal that charge injection from the electrode constitute the predominant process responsible for the dark current. The latter is nearly identical in positive and negative polarities, and shows an exponential increase versus the relative humidity and the electric field. The analysis of results shows that under high electric field, the emission of charged water clusters from the water films adsorbed on electrodes probably constitutes the main mechanism of charge emission. (paper)

  10. Dark current measurements in humid SF6: influence of electrode roughness, relative humidity and pressure

    Science.gov (United States)

    Zavattoni, L.; Hanna, R.; Lesaint, O.; Gallot-Lavallée, O.

    2015-09-01

    The measurement of ‘dark current’ in pressurized SF6 at high electric field is performed using electrodes with a coaxial geometry. To identify the main mechanisms involved in measured currents, the influences of electrode roughness, gas pressure and relative humidity have been investigated. The experimental results reveal that charge injection from the electrode constitute the predominant process responsible for the dark current. The latter is nearly identical in positive and negative polarities, and shows an exponential increase versus the relative humidity and the electric field. The analysis of results shows that under high electric field, the emission of charged water clusters from the water films adsorbed on electrodes probably constitutes the main mechanism of charge emission.

  11. Influence of pressurizer relief valves on success of ''feed and bleed'' procedure

    International Nuclear Information System (INIS)

    The RELAP5/MOD3.1 analysis of the accident with total loss of secondary heat sink was performed for Krsko nuclear power plant which is a two loop Westinghouse PWR power plant of 1,876 MW thermal power. In the study of ''feed and bleed'' accident managing the particular attention was given to the emergency operating procedures foreseen operator actions. This paper deals with the modeling of saturated liquid and two-phase mixture critical discharge through the pressurizer power operated relief valves and aims to evaluate its influence on the simulation of other thermal-hydraulic processes in the reactor coolant system. The time evolution of simulated accident and the determination of the longest allowed operator response time for the successful accident managing were shown to be much dependent on the prediction of critical flow through the pressurizer relief valves

  12. The influence of peak shock stress on the high pressure phase transformation in Zr

    International Nuclear Information System (INIS)

    At high pressures zirconium is known to undergo a phase transformation from the hexagonal close packed (HCP) alpha phase to the simple hexagonal omega phase. Under conditions of shock loading, a significant volume fraction of high-pressure omega phase is retained upon release. However, the hysteresis in this transformation is not well represented by equilibrium phase diagrams and the multi-phase plasticity under shock conditions is not well understood. For these reasons, the influence of peak shock stress and temperature on the retention of omega phase in Zr has been explored. VISAR and PDV measurements along with post-mortem metallographic and neutron diffraction characterization of soft recovered specimens have been utilized to quantify the volume fraction of retained omega phase and qualitatively understand the kinetics of this transformation. In turn, soft recovered specimens with varying volume fractions of retained omega phase have been utilized to understand the contribution of omega and alpha phases to strength in shock loaded Zr.

  13. All-cause mortality from obstructive sleep apnea in male and female patients with and without continuous positive airway pressure treatment: a registry study with 10 years of follow-up

    Directory of Open Access Journals (Sweden)

    Jennum P

    2015-04-01

    Full Text Available Poul Jennum,1,2 Philip Tønnesen,1 Rikke Ibsen,3 Jakob Kjellberg4 1Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Glostrup Hospital, Copenhagen, Denmark; 2Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; 3itracks, Aarhus, Denmark, 4Danish National Institute for Local and Regional Government Research, Copenhagen, Denmark 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 selected from the Danish National Patient Registry for the period 1999–2009. We used Cox proportional hazard function to evaluate the all-cause mortality from OSA in middle-aged and elderly males and females who were treated, or not, with CPAP. Results: Female OSA patients had a lower mortality than males, irrespective of whether they received CPAP treatment. CPAP treatment improved survival, as illustrated by the hazard ratio of 0.62 (P<0.001. This effect was dependent on gender: CPAP had no significant effect on 20- to 39-year-old males and females, but the overall mortality in this age group was small. Survival was increased by CPAP in 40- to 59-year-old and ≥60-year-old males, but no such effect was observed in females. Positive predictors of survival were young age, female gender, higher educational level, and low 3-year prior comorbidity as estimated by the Charlson Comorbidity Index. Negative predictors for survival were male gender, age ≥60 years, no CPAP treatment, prior comorbidity, and low educational level. Conclusion: CPAP therapy is associated with reduced all-cause mortality in middle-aged and elderly males, but no significant effect was found in females. Keywords: middle age, elderly, gender, mortality

  14. Overnight urinary uric acid: creatinine ratio for detection of sleep hypoxemia. Validation study in chronic obstructive pulmonary disease and obstructive sleep apnea before and after treatment with nasal continuous positive airway pressure.

    Science.gov (United States)

    Braghiroli, A; Sacco, C; Erbetta, M; Ruga, V; Donner, C F

    1993-07-01

    During hypoxia ATP degradation to uric acid is increased in animal models and humans. To assess the reliability of an overnight increase in uric acid excretion as a marker of nocturnal hypoxemia, we selected 10 normal volunteers (7 males and 3 females), 29 COPD patients (26 males and 3 females), and 49 subjects with obstructive sleep apnea (OSA) (43 males and 6 females). The patients underwent standard polysomnography, which was repeated in 14 subjects with nasal continuous positive airway pressure (CPAP), and were subdivided into two groups: Group D included desaturating subjects who spent at least 1 h at SaO2 < 90% and 15 min below 85%, and Group ND were nondesaturating subjects. The overnight change in the uric acid:creatinine ratio (delta UA:Cr) was negative in normal subjects (-27.5 +/- 9.1 [mean +/- SD]) and ND groups: -19.7 +/- 14.3 in COPD, -16.1 +/- 13.0 in OSA. In both COPD and OSA Group D, the ratio was usually positive: delta UA:Cr was 17.9 +/- 31.4 in Group D COPD (p < 0.001 versus ND) and 10.1 +/- 30.7 in Group D OSA (p < 0.001 versus ND and versus normal subjects) despite 4 of 15 false negative results in COPD and 8 of 20 in OSA. CPAP effective treatment induced a marked reduction ((p = 0.0024) in delta UA:Cr, leading to a negative value. We conclude that delta UA:Cr seems to be a promising index of significant nocturnal tissue hypoxia, with good specificity but poor sensitivity (about 30% false negative), which might be useful for the long-term follow-up of outpatients on nasal CPAP with a positive ratio at baseline. PMID:8317794

  15. Analysing the influence of preferential flow on pressure transmission and landslide triggering

    Science.gov (United States)

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

    2015-04-01

    Rainfall-induced shallow landslides are the most frequent natural hazards in mountainous areas. As a result of rainfall, an increase in pore water pressure reduces the effective stress and shear strength of a slope, which could further trigger the occurrence of slope failure. Recognizably, such landslides are characterized by thresholds of rainfall magnitude and intensity, which are commonly evaluated in hydro-mechanical models via integration of a hydrological and a soil mechanics model. Mechanisms of slope instability and water pressure transmission in a natural subsurface hydrological system are very complex, because the soil hydraulic behaviours in the saturated and the unsaturated zones are rather different. Regarding the pressure transmission mechanism, in the saturated zone the pressure wave propagation is nearly instant, while, in the unsaturated zone the pressure fluctuates due to the variability of soil moisture content and the existence of preferential flow. However, the diffusion wave model has been derived to quantify the celerity of pressure waves in a near-saturated soil and also been applied in the landslide triggering analysis. Yet, the functionality of the preferential flow in landslide-triggering mechanisms under the high-intensity rainstorm is rarely quantified, and its role in pressure wave propagation is not well studied. The pore water pressure is still calculated based on a single-permeability assumption in most hydro-mechanical models. The dual-permeability approach, however, couples the matrix flow and preferential flow with two Richards equations, which has a great potential to investigate the influence of preferential flow on pressure transmission and slope stability in a heterogeneous hillslope. In this study, a hydro-mechanical model was developed that couples a 1D dual-permeability model with an infinite slope stability analysis. A series of synthetic experiments simulates and quantifies the rainfall amount, intensity, and duration

  16. The influence of chemicals on water quality in a high pressure separation rig

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, Einar E.; Hemmingsen, Paal V.; Mediaas, Heidi; Svarstad, May Britt E.; Westvik, Arild

    2006-03-15

    In the research laboratory of Statoil at Rotvoll, Trondheim, a high pressure experimental rig used for separation and foaming studies has been developed. There have been several studies to ensure that the high pressure separation rig produces reliable and consistent results with regard to the water-in-oil and oil-in-water contents. The results are consistent with available field data and, just as important, consistent when changing variables like temperature, pressure drop and water cut. The results are also consistent when changing hydrodynamic variables like flow velocity and mixing point (using different choke valves) and when using oil with and without gas saturation. At equal experimental conditions, the high pressure separation rig is able to differentiate between separation characteristics of oil and water from different fields and from different wells at the same field. The high pressure separation and foam rig can be used from -10 deg C to 175 deg C and at pressures up to 200 bar. Crude oil and water are studied under relevant process conditions with respect to temperature, pressure, shear, water cut and separation time. In the present work the influence of chemicals on the oil and water quality has been studied. Chemicals have been mixed into the oil and/or water beforehand or added in situ (on-stream; simulated well stream). The amount of oil in the water after a given residence time in the separation cell has been measured. The results from the high pressure rig show that some demulsifiers, with their primary purpose of giving less water in oil, also have influence on the water quality. Improvement of water quality has been observed as well as no effect or aggravation. The experimental results have been compared to results from bottle tests at the field. The results from the bottle tests and from the laboratory are not corresponding, and only a full-scale field test can tell which of them are the correct results, if any. (Experience from corresponding

  17. Influences of Models on the Unsteady Pressure Characteristics of the NASA National Transonic Facility

    Science.gov (United States)

    Jones, Gregory; Balakrishna, Sundareswara; DeMoss, Joshua; Goodliff, Scott; Bailey, Matthew

    2015-01-01

    Pressure fluctuations have been measured over the course of several tests in the National Transonic Facility to study unsteady phenomenon both with and without the influence of a model. Broadband spectral analysis will be used to characterize the length scales of the tunnel. Special attention will be given to the large-scale, low frequency data that influences the Mach number and force and moment variability. This paper will also discuss the significance of the vorticity and sound fields that can be related to the Common Research Model and will also highlight the comparisons to an empty tunnel configuration. The effectiveness of vortex generators placed at the interface of the test section and wind tunnel diffuser showed promise in reducing the empty tunnel unsteadiness, however, the vortex generators were ineffective in the presence of a model.

  18. The temperature and oxygen pressure influence on the iron secondary ion emission

    International Nuclear Information System (INIS)

    Investigations of secondary ion composition, ejected from the iron surface by an Ar+ beam with E=2keV and current density 5 x 10-7A/cm2, were carried out. The influence of the target temperature and oxygen partial pressure value near its surface on the composition and quantitative ratio of flow values of secondary ions ejected from the target is shown. A strong effect of bulk admixtures (C.S.P) on the temperature dependences of mass line intensities of secondary ions of oxides, carbides, sulphides and phosphides of iron in the high temperature ranges is discovered. The influence of two mechanisms of carbon diffusion on coverage size of the target surface by iron carbides is observed. (Auth.)

  19. Influence of longitudinal argon flow on DC glow discharge at atmospheric pressure

    Science.gov (United States)

    Zhu, Sha; Jiang, Weiman; Tang, Jie; Xu, Yonggang; Wang, Yishan; Zhao, Wei; Duan, Yixiang

    2016-05-01

    A one-dimensional self-consistent fluid model was employed to investigate the influence of longitudinal argon flow on the DC glow discharge at atmospheric pressure. It is found that the charges exhibit distinct dynamic behaviors at different argon flow velocities, accompanied by a considerable change in the discharge structure. The positive argon flow allows for the reduction of charge densities in the positive column and negative glow regions, and even leads to the disappearance of negative glow. The negative argon flow gives rise to the enhancement of charge densities in the positive column and negative glow regions. These observations are attributed to the fact that the gas flow convection influences the transport of charges through different manners by comparing the argon flow velocity with the ion drift velocity. The findings are important for improving the chemical activity and work efficiency of the plasma source by controlling the gas flow in practical applications.

  20. 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.

  1. The influences of positive end expiratory pressure (PEEP associated with physiotherapy intervention in phase I cardiac rehabilitation

    Directory of Open Access Journals (Sweden)

    Borghi-Silva Audrey

    2005-01-01

    Full Text Available PURPOSE: To evaluate the effects of positive end expiratory pressure and physiotherapy intervention during Phase I of cardiac rehabilitation on the behavior of pulmonary function and inspiratory muscle strength in postoperative cardiac surgery. METHODS: A prospective randomized study, in which 24 patients were divided in 2 groups: a group that performed respiratory exercises with positive airway expiratory pressure associated with physiotherapy intervention (GEP, n = 8 and a group that received only the physiotherapy intervention (GPI, n = 16. Pulmonary function was evaluated by spirometry on the preoperative and on the fifth postoperative days; inspiratory muscle strength was measured by maximal inspiratory pressure on the same days. RESULTS: Spirometric variables were significantly reduced from the preoperative to the fifth postoperative day for the GPI, while the GEP had a significant reduction only for vital capacity (P < .05. When the treatments were compared, smaller values were observed in the GPI for peak flow on the fifth postoperative day. Significant reductions of maximal inspiratory pressure from preoperative to the first postoperative day were found in both groups. However, the reduction in maximal inspiratory pressure from the preoperative to the fifth postoperative day was significant only in the GPI (P < .05. CONCLUSIONS: These data suggest that cardiac surgery produces a reduction in inspiratory muscle strength, pulmonary volume, and flow. The association of positive expiratory pressure with physiotherapy intervention was more efficient in minimizing these changes, in comparison to the physiotherapy intervention alone. However, in both groups, the pulmonary volumes were not completely reestablished by the fifth postoperative day, and it was necessary to continue the treatment after hospital convalescence.

  2. Surface pretreatment of plastics with an atmospheric pressure plasma jet - Influence of generator power and kinematics

    International Nuclear Information System (INIS)

    The industrial use of atmospheric pressure plasmas in the plastics processing industry has increased significantly in recent years. Users of this treatment process have the possibility to influence the target values (e.g. bond strength or surface energy) with the help of kinematic and electrical parameters. Until now, systematic procedures have been used with which the parameters can be adapted to the process or product requirements but only by very time-consuming methods. For this reason, the relationship between influencing values and target values will be examined based on the example of a pretreatment in the bonding process with the help of statistical experimental design. Because of the large number of parameters involved, the analysis is restricted to the kinematic and electrical parameters. In the experimental tests, the following factors are taken as parameters: gap between nozzle and substrate, treatment velocity (kinematic data), voltage and duty cycle (electrical data). The statistical evaluation shows significant relationships between the parameters and surface energy in the case of polypropylene. An increase in the voltage and duty cycle increases the polar proportion of the surface energy, while a larger gap and higher velocity leads to lower energy levels. The bond strength of the overlapping bond is also significantly influenced by the voltage, velocity and gap. The direction of their effects is identical with those of the surface energy. In addition to the kinematic influences of the motion of an atmospheric pressure plasma jet, it is therefore especially important that the parameters for the plasma production are taken into account when designing the pretreatment processes

  3. Surface pretreatment of plastics with an atmospheric pressure plasma jet - Influence of generator power and kinematics

    Science.gov (United States)

    Moritzer, E.; Leister, C.

    2014-05-01

    The industrial use of atmospheric pressure plasmas in the plastics processing industry has increased significantly in recent years. Users of this treatment process have the possibility to influence the target values (e.g. bond strength or surface energy) with the help of kinematic and electrical parameters. Until now, systematic procedures have been used with which the parameters can be adapted to the process or product requirements but only by very time-consuming methods. For this reason, the relationship between influencing values and target values will be examined based on the example of a pretreatment in the bonding process with the help of statistical experimental design. Because of the large number of parameters involved, the analysis is restricted to the kinematic and electrical parameters. In the experimental tests, the following factors are taken as parameters: gap between nozzle and substrate, treatment velocity (kinematic data), voltage and duty cycle (electrical data). The statistical evaluation shows significant relationships between the parameters and surface energy in the case of polypropylene. An increase in the voltage and duty cycle increases the polar proportion of the surface energy, while a larger gap and higher velocity leads to lower energy levels. The bond strength of the overlapping bond is also significantly influenced by the voltage, velocity and gap. The direction of their effects is identical with those of the surface energy. In addition to the kinematic influences of the motion of an atmospheric pressure plasma jet, it is therefore especially important that the parameters for the plasma production are taken into account when designing the pretreatment processes.

  4. Upper airway evaluation

    International Nuclear Information System (INIS)

    The authors are evaluating upper-airway sleep disorders with magnetic resonance (MR) imaging and x-ray cine computed tomography (CT). Fixed structural anatomy is visualized with multisection spin-echo MR imaging, the dynamic component with cine CT. Unique aspects of the study are described in this paper

  5. The influence of the radial pressure gradient on the blade root loss in an annular subsonic nozzle cascade

    Science.gov (United States)

    Meng, D.; Weng, Z.; Xiang, Y.

    1985-09-01

    This paper presents a method for predicting the blade root loss in an annular nozzle cascade in which consideration is given to the influence of the radial pressure gradient (RPG) on it. The variation of blade root losses under different RPG is obtained experimentally, and finite element method is used to calculate the pressure distribution in the blade passage.

  6. 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...

  7. Stress-intensity-factor influence coefficients for axial and circumferential flaws in reactor pressure vessels

    International Nuclear Information System (INIS)

    Weight-function techniques in linear elastic fracture mechanics utilize stress-intensity-factor influence coefficients K* and superposition principles to compute stress intensity factors. This paper presents influence coefficients for two flaw geometries often employed in fracture analyses of reactor pressure vessels: (1) infinitely long, axial, inside-surface flaws and (2) 360 degrees, circumferential, inside-surface flaws. Calculations were performed using ABAQUS, a nuclear quality assurance (NQA-1) certified finite-element program which employs a highly accurate crack extension technique for the computation of theJ-integral. Influence coefficients are computed for flaw depths in the range 0.01 ≤ a/T ≤ 0.9 with particular emphasis on shallow flaws (a/T ≤ 0. 1). This study addresses vessels having R/T = 10 which is appropriate for most PWRs in USA. The influence coefficients have been implemented in the FAVOR fracture-mechanics code currently being developed under the NRC-funded HSST Program at ORNL

  8. Compensatory responses to upper airway obstruction in obese apneic men and women

    OpenAIRE

    Chin, Chien-Hung; Kirkness, Jason P.; Patil, Susheel P.; McGinley, Brian M.; Smith, Philip L.; Schwartz, Alan R.; Schneider, Hartmut

    2011-01-01

    Defective structural and neural upper airway properties both play a pivotal role in the pathogenesis of obstructive sleep apnea. A more favorable structural upper airway property [pharyngeal critical pressure under hypotonic conditions (passive Pcrit)] has been documented for women. However, the role of sex-related modulation in compensatory responses to upper airway obstruction (UAO), independent of the passive Pcrit, remains unclear. Obese apneic men and women underwent a standard polysomno...

  9. Supraglottic airway devices in children

    Science.gov (United States)

    Ramesh, S; Jayanthi, R

    2011-01-01

    Modern anaesthesia practice in children was made possible by the invention of the endotracheal tube (ET), which made lengthy and complex surgical procedures feasible without the disastrous complications of airway obstruction, aspiration of gastric contents or asphyxia. For decades, endotracheal intubation or bag-and-mask ventilation were the mainstays of airway management. In 1983, this changed with the invention of the laryngeal mask airway (LMA), the first supraglottic airway device that blended features of the facemask with those of the ET, providing ease of placement and hands-free maintenance along with a relatively secure airway. The invention and development of the LMA by Dr. Archie Brain has had a significant impact on the practice of anaesthesia, management of the difficult airway and cardiopulmonary resuscitation in children and neonates. This review article will be a brief about the clinical applications of supraglottic airways in children. PMID:22174464

  10. The influence of water on the Peierls stress of olivine at high pressures

    Science.gov (United States)

    Mei, S.; Suzuki, A. M.; Xu, L.; Kohlstedt, D. L.; Dixon, N. A.; Durham, W. B.

    2012-04-01

    To investigate the influence of water on the low-temperature plasticity of olivine under lithospheric conditions, we carried out a series of creep experiments on polycrystalline olivine at high pressures (~6 GPa), relatively low temperatures (873 ≤ T ≤ 1173 K), and hydrous conditions using a deformation-DIA. Samples were fabricated from fine powdered San Carlos olivine under hydrous conditions. In the experiments, a sample column composed of a sample and alumina pistons was assembled with a talc sleeve and graphite resistance heater into a 6.2-mm edge length cubic pressure medium. Experiments were carried out at the National Synchrotron Light Source at Brookhaven National Laboratory. In a run, differential stress and sample displacement were monitored in-situ using synchrotron x-ray diffraction and radiography, respectively. The low-temperature plasticity of olivine under hydrous conditions is constrained by our data with a Peierls stress of 4.2 ± 0.3 GPa. This value is much lower than those reported the Peierls stress for olivine under anhydrous conditions (~ 6 - 15 GPa, Evans and Goetze, 1979; Raterron et al., 2004; Mei at al., 2010), indicating a significant influence of water on the low-temperature plasticity of olivine. The low-temperature flow behavior of olivine under hydrous conditions quantified in this study provides a necessary constraint for modeling the dynamic activities occurring within lithospheric mantle especially for those regions with the presence of water such as beneath a mid-ocean ridge and along a subducting slab.

  11. Management of the Traumatized Airway.

    Science.gov (United States)

    Jain, Uday; McCunn, Maureen; Smith, Charles E; Pittet, Jean-Francois

    2016-01-01

    There is a lack of evidence-based approach regarding the best practice for airway management in patients with a traumatized airway. General recommendations for the management of the traumatized airway are summarized in table 5. Airway trauma may not be readily apparent, and its evaluation requires a high level of suspicion for airway disruption and compression. For patients with facial trauma, control of the airway may be significantly impacted by edema, bleeding, inability to clear secretions, loss of bony support, and difficulty with face mask ventilation. With the airway compression from neck swelling or hematoma, intubation attempts can further compromise the airway due to expanding hematoma. For patients with airway disruption, the goal is to pass the tube across the injured area without disrupting it or to insert the airway distal to the injury using a surgical approach. If airway injury is extensive, a surgical airway distal to the site of injury may be the best initial approach. Alternatively, if orotracheal intubation is chosen, spontaneous ventilation may be maintained or RSI may be performed. RSI is a common approach. Thus, some of the patients intubated may subsequently require tracheostomy. A stable patient with limited injuries may not require intubation but should be watched carefully for at least several hours. Because of a paucity of evidence-based data, the choice between these approaches and the techniques utilized is a clinical decision depending on the patient's condition, clinical setting, injuries to airway and other organs, and available personnel, expertise, and equipment. Inability to obtain a definitive airway is always an absolute indication for an emergency cricothyroidotomy or surgical tracheostomy. PMID:26517857

  12. Influence of flow rate on aerosol particle size distributions from pressurized and breath-actuated inhalers.

    Science.gov (United States)

    Smith, K J; Chan, H K; Brown, K F

    1998-01-01

    Particle size distribution of delivered aerosols and the total mass of drug delivered from the inhaler are important determinants of pulmonary deposition and response to inhalation therapy. Inhalation flow rate may vary between patients and from dose to dose. The Andersen Sampler (AS) cascade impactor operated at flow rates of 30 and 55 L/min and the Marple-Miller Impactor (MMI) operated at flow rates of 30, 55, and 80 L/min were used in this study to investigate the influence of airflow rate on the particle size distributions of inhalation products. Total mass of drug delivered from the inhaler, fine particle mass, fine particle fraction, percentage of nonrespirable particles, and amount of formulation retained within the inhaler were determined by ultraviolet spectrophotometry for several commercial bronchodilator products purchased in the marketplace, including a pressurized metered-dose inhaler (pMDI), breath-actuated pressurized inhaler (BAMDI), and three dry powder inhalers (DPIs), two containing salbutamol sulphate and the other containing terbutaline sulphate. Varying the flow rate through the cascade impactor produced no significant change in performance of the pressurized inhalers. Increasing the flow rate produced a greater mass of drug delivered and an increase in respirable particle mass and fraction from all DPIs tested. PMID:10346666

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

    International Nuclear Information System (INIS)

    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 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.

  15. 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

  16. 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.

  17. Deposition of inhalated radionuclides in computer topographically reconstructed human airways

    International Nuclear Information System (INIS)

    Health effects of inhaled radio aerosols highly depend on their deposition patterns within the respiratory system. In addition, several pulmonary health diseases are characteristic to the tracheobronchial tree and most of them are provoked by inhaled aerosols. Local features of particle deposition are strongly influenced by the applied computational model in order to describe airway morphology. Current aerosol deposition models apply strongly idealised geometries of the airways for the description of aerosol deposition. They approximate the surface of the tracheo-bronchial airways with circular cross-section bifurcation units and cylinders. Medical endoscopic, post-mortem and other examinations show that the geometry of the real tracheo-bronchial tree is much more complex. The surface of the conducting airways is not perfectly smooth, especially in case of a diseased lung when even the mucus production excess is not negligible. Furthermore, the morphology of the airways constantly changes during at in vivo circumstances. In summary, the exact numerical description of the complex surface of the human airways is impossible, but a quite realistic approach can be achieved by applying medical imaging techniques to describe the geometry of the airways

  18. The influence of the equivalent hydraulic diameter on the pressure drop prediction of annular test section

    Science.gov (United States)

    Al-Kayiem, A. H. H.; Ibrahim, M. A.

    2015-12-01

    The flow behaviour and the pressure drop throughout an annular flow test section was investigated in order to evaluate and justify the reliability of experimental flow loop for wax deposition studies. The specific objective of the present paper is to assess and highlight the influence of the equivalent diameter method on the analysis of the hydrodynamic behaviour of the flow and the pressure drop throughout the annular test section. The test section has annular shape of 3 m length with three flow passages, namely; outer thermal control jacket, oil annular flow and inner pipe flow of a coolant. The oil annular flow has internal and external diameters of 0.0422 m and 0.0801 m, respectively. Oil was re-circulated in the annular passage while a cold water-glycol mixture was re-circulated in the inner pipe counter currently to the oil flow. The experiments were carried out at oil Reynolds number range of 2000 to 17000, covering laminar, transition and turbulent flow regimes. Four different methods of equivalent diameter of the annulus have been considered in this hydraulic analysis. The correction factor model for frictional pressure drop was also considered in the investigations. All methods addressed the high deviation of the prediction from the experimental data, which justified the need of a suitable pressure prediction correlation for the annular test section. The conventional hydraulic diameter method is a convenient substitute for characterizing physical dimension of a non-circular duct, and it leads to fairly good correlation between turbulent fluid flow and heat transfer characteristic of annular ducts.

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

    International Nuclear Information System (INIS)

    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.

  20. 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.

  1. The influence of pressure-dependent variation of the elastic constants on tunnelling systems in amorphous solids

    Science.gov (United States)

    Eggert, Th.; Geilenkeuser, R.; Jäckel, M.

    2000-07-01

    We have measured the dielectric response ε( ω) and the thermal conductivity κ of polystyrene (PS) and of polycarbonate (PC) under high hydrostatic pressure (0.1 MPapressure influence on the minimum temperature of Δ ε‧/ ε‧ and on κ. With the pressure dependence of the density and sound velocity of PC and PS the influence of pressure on the tunnelling constant Ci can be determined. These results show that the product P¯γ l,t2 of the standard tunnelling model (STM) scales with the pressure-dependent elastic constants c11 and c44.

  2. Influence of upstream stator on rotor flutter stability in a low pressure steam turbine stage

    Energy Technology Data Exchange (ETDEWEB)

    Huang, X.; He, L. [University of Durham (United Kingdom). School of Engineering; Bell, D. [ALSTOM Power Ltd., Rugby (United Kingdom)

    2006-07-01

    Conventional blade flutter prediction is normally based on an isolated blade row model, however, little is known about the influence of adjacent blade rows. In this article, an investigation is presented into the influence of the upstream stator row on the aero-elastic stability of rotor blades in the last stage of a low pressure (LP) steam turbine. The influence of the upstream blade row is computed directly by a time-marching, unsteady, Navier-Stokes flow solver in a stator-rotor coupled computational domain. The three-dimensional flutter solution is obtained, with adequate mesh resolution, in a single passage domain through application of the Fourier-Transform based Shape-Correction method. The capability of this single-passage method is examined through comparison with predictions obtained from a complete annulus model, and the results demonstrate a good level of accuracy, while achieving a speed up factor of 25. The present work shows that the upstream stator blade row can significantly change the aero-elastic behaviour of an LP steam turbine rotor. Caution is, therefore, advised when using an isolated blade row model for blade flutter prediction. The results presented also indicated that the intra-row interaction is of a strong three-dimensional nature. (author)

  3. Air-Q intubating laryngeal airway: A study of the second generation supraglottic airway device

    Science.gov (United States)

    Attarde, Viren Bhaskar; Kotekar, Nalini; Shetty, Sarika M

    2016-01-01

    Background and Aims: Air-Q intubating laryngeal mask airway (ILA) is used as a supraglottic airway device and as a conduit for endotracheal intubation. This study aims to assess the efficacy of the Air-Q ILA regarding ease of insertion, adequacy of ventilation, rate of successful intubation, haemodynamic response and airway morbidity. Methods: Sixty patients presenting for elective surgery at our Medical College Hospital were selected. Following adequate premedication, baseline vital parameters, pulse rate and blood pressure were recorded. Air-Q size 3.5 for patients 50-70 kg and size 4.5 for 70-100 kg was selected. After achieving adequate intubating conditions, Air-Q ILA was introduced. Confirming adequate ventilation, appropriate sized endotracheal tube was advanced through the Air-Q blindly to intubate the trachea. Placement of the endotracheal tube in trachea was confirmed. Results: Air-Q ILA was successfully inserted in 88.3% of patients in first attempt and 11.7% patients in second attempt. Ventilation was adequate in 100% of patients. Intubation was successful in 76.7% of patients with Air-Q ILA. 23.3% of patients were intubated by direct laryngoscopy following failure with two attempts using Air-Q ILA. Post-intubation the change in heart rate was statistically significant (P < 0.0001). 10% of patients were noted to have a sore throat and 5% of patients had mild airway trauma. Conclusion: Air-Q ILA is a reliable device as a supraglottic airway ensuring adequate ventilation as well as a conduit for endotracheal intubation. It benefits the patient by avoiding the stress of direct laryngoscopy and is also superior alternative device for use in a difficult airway. PMID:27212722

  4. Airways Disease: Phenotyping Heterogeneity Using Measures of Airway Inflammation

    OpenAIRE

    Siddiqui Salman; Brightling Christopher E

    2007-01-01

    Despite asthma and chronic obstructive pulmonary disease being widely regarded as heterogeneous diseases, a consensus for an accurate system of classification has not been agreed. Recent studies have suggested that the recognition of subphenotypes of airway disease based on the pattern of airway inflammation may be particularly useful in increasing our understanding of the disease. The use of non-invasive markers of airway inflammation has suggested the presence of four distinct phenotypes: ...

  5. 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.

  6. Upper airway collapsibility, dilator muscle activation and resistance in sleep apnoea

    OpenAIRE

    Pierce, R.; White, D.; Malhotra, A; Edwards, J. K.; Kleverlaan, D.; Palmer, L.; J. Trinder

    2007-01-01

    The calibre of the upper airway is thought to be dependant upon its passive anatomy/collapsibility and the activation of pharyngeal dilator muscles. During awake periods, the more collapsible upper airway in obstructive sleep apnoea (OSA) increases the dilator muscle activity through a negative-pressure reflex.

  7. Brachycephalic airway syndrome.

    Science.gov (United States)

    Meola, Stacy D

    2013-08-01

    Brachycephalic airway syndrome is a common finding in brachycephalic breeds. A combination of primary and secondary changes can progress to life-threatening laryngeal collapse. Early recognition of primary anatomic abnormalities that include stenotic nares, elongated soft palate, and hypoplastic trachea would allow the clinician to make early recommendations for medical and surgical management, which can improve the quality of life in affected animals. PMID:24182996

  8. Influence of pressure derivative of partition function on thermodynamic properties of non-local thermodynamic equilibrium thermal plasma

    Science.gov (United States)

    Singh, Gurpreet; Sharma, Rohit; Singh, Kuldip

    2015-09-01

    Thermodynamic properties (compressibility coefficient Z γ , specific heat at constant volume c v , adiabatic coefficient γ a , isentropic coefficient γ i s e n , and sound speed c s ) of non-local thermodynamic equilibrium hydrogen thermal plasma have been investigated for different values of pressure and non-equilibrium parameter θ (=Te/Th) in the electron temperature range from 6000 K to 60 000 K. In order to estimate the influence of pressure derivative of partition function on thermodynamic properties, two cases have been considered: (a) in which pressure derivative of partition function is taken into account in the expressions and (b) without pressure derivative of partition function in their expressions. Here, the case (b) represents expressions already available in literature. It has been observed that the temperature from which pressure derivative of partition function starts influencing a given thermodynamic property increases with increase of pressure and non-equilibrium parameter θ. Thermodynamic property in the case (a) is always greater than its value in the case (b) for compressibility coefficient and specific heat at constant volume, whereas for adiabatic coefficient, isentropic coefficient, and sound speed, its value in the case (a) is always less than its value in the case (b). For a given value of θ, the relationship of compressibility coefficient with degree of ionization depends upon pressure in the case (a), whereas it is independent of pressure in the case (b). Relative deviation between the two cases shows that the influence of pressure derivative of partition function is significantly large and increases with the augmentation of pressure and θ for compressibility coefficient, specific heat at constant volume, and adiabatic coefficient, whereas for isentropic coefficient and sound speed, it is marginal even at high values of pressure and non-equilibrium parameter θ.

  9. Efeitos da aplicação da EPAP (Expiratory Positive Airway Pressure sobre a tolerância ao esforço em pacientes portadores de insuficiência cardíaca

    Directory of Open Access Journals (Sweden)

    Claudia Thofehrn

    2013-04-01

    Full Text Available INTRODUÇÃO: Novas abordagens terapêuticas que objetivam melhorar a sensação de dispneia e fadiga em pacientes com insuficiência cardíaca, como a aplicação de pressão positiva expiratória nas vias aéreas (EPAP, podem ser aplicadas na tentativa de melhorar a capacidade funcional e a qualidade de vida. OBJETIVO: Avaliar os efeitos da utilização da EPAP ( Expiratory Positive Airway Pressure durante o esforço em indivíduos portadores de IC classe funcional II e III (NYHA. MÉTODOS: Dos 390 pacientes, foram selecionados 28 com FEVE < 40%. O Teste de Caminhada de seis minutos (TC6' foi realizado três vezes: o primeiro para a familiarização, um com a máscara e o outro sem a máscara de EPAP, sendo válido os dois últimos. A comparação entre os dados obtidos foi realizada por meio de teste t de Student pareado ou teste de Wilcoxon, conforme a normalidade dos dados. RESULTADOS: a percepção de esforço foi maior após a caminhada com a utilização da máscara quando comparado na ausência da máscara. Houve elevação significativa na saturação de oxigênio quando os pacientes estavam usando a máscara de EPAP. CONCLUSÃO: O uso da máscara de EPAP aumenta a percepção de esforço e o trabalho ventilatório, porém, não aumentou a distância percorrida no TC6, sendo sua aplicabilidade questionável em programas de reabilitação cardiovascular.

  10. Lipids in airway secretions

    International Nuclear Information System (INIS)

    Lipids form a significant portion of airway mucus yet they have not received the same attention that epithelial glycoproteins have. We have analysed, by thin layer chromatography, lipids present in airway mucus under 'normal' and hypersecretory (pathological) conditions.The 'normals' included (1) bronchial lavage obtained from healthy human volunteers and from dogs and (2) secretions produced ''in vitro'' by human (bronchial) and canine (tracheal) explants. Hypersecretory mucus samples included (1) lavage from dogs made bronchitic by exposure to SO2, (2) bronchial aspirates from acute and chronic tracheostomy patients, (3) sputum from patients with cystic fibrosis and chronic bronchitis and (4) postmortem secretions from patients who died from sudden infant death syndrome (SIDS) or from status asthmaticus. Cholesterol was found to be the predominant lipid in 'normal' mucus with lesser amounts of phospholipids. No glycolipids were detected. In the hypersecretory mucus, in addition to neutral and phospholipids, glycolipids were present in appreciable amounts, often the predominant species, suggesting that these may be useful as markers of disease. Radioactive precursors 14C acetate and 14C palmitate were incorporated into lipids secreted ''in vitro'' by canine tracheal explants indicating that they are synthesised by the airway. (author)

  11. Lipids in airway secretions

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskar, K.R.; DeFeudis O' Sullivan, D.; Opaskar-Hincman, H.; Reid, L.M.

    1987-01-01

    Lipids form a significant portion of airway mucus yet they have not received the same attention that epithelial glycoproteins have. We have analysed, by thin layer chromatography, lipids present in airway mucus under 'normal' and hypersecretory (pathological) conditions.The 'normals' included (1) bronchial lavage obtained from healthy human volunteers and from dogs and (2) secretions produced ''in vitro'' by human (bronchial) and canine (tracheal) explants. Hypersecretory mucus samples included (1) lavage from dogs made bronchitic by exposure to SO/sub 2/, (2) bronchial aspirates from acute and chronic tracheostomy patients, (3) sputum from patients with cystic fibrosis and chronic bronchitis and (4) postmortem secretions from patients who died from sudden infant death syndrome (SIDS) or from status asthmaticus. Cholesterol was found to be the predominant lipid in 'normal' mucus with lesser amounts of phospholipids. No glycolipids were detected. In the hypersecretory mucus, in addition to neutral and phospholipids, glycolipids were present in appreciable amounts, often the predominant species, suggesting that these may be useful as markers of disease. Radioactive precursors /sup 14/C acetate and /sup 14/C palmitate were incorporated into lipids secreted ''in vitro'' by canine tracheal explants indicating that they are synthesised by the airway.

  12. Influence of processing parameters on atmospheric pressure plasma etching of polyamide 6 films

    Energy Technology Data Exchange (ETDEWEB)

    Gao Zhiqiang; Peng Shujing; Sun Jie; Yao Lan [Key Laboratory of Textile Science and Technology, Ministry of Education (China); College of Textiles, Donghua University, Shanghai 201620 (China); Qiu Yiping, E-mail: ypqiu@dhu.edu.cn [Key Laboratory of Textile Science and Technology, Ministry of Education (China); College of Textiles, Donghua University, Shanghai 201620 (China)

    2009-06-15

    This study is designed to systematically investigate how various factors, such as treatment duration, output power, oxygen gas flux, jet to substrate distance, and moisture regain, influence atmospheric pressure plasma etching rate of polyamide 6 (PA 6) films. The etching rate increased as the output power, oxygen gas flux, and moisture regain increased. As the treatment time increased, the etching rate increased first and then decreased. When the substrate was too close or too far from the nozzle, the etching rate was almost not measurable. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) show an increased surface roughness after the plasma treatment. X-ray photoelectron spectroscopy (XPS) shows a decreased carbon content and an increased oxygen content after the plasma treatment. T-peel strength shows an improved bonding strength between the PA 6 films and an adhesive tape after the plasma treatment.

  13. Influence of processing parameters on atmospheric pressure plasma etching of polyamide 6 films

    International Nuclear Information System (INIS)

    This study is designed to systematically investigate how various factors, such as treatment duration, output power, oxygen gas flux, jet to substrate distance, and moisture regain, influence atmospheric pressure plasma etching rate of polyamide 6 (PA 6) films. The etching rate increased as the output power, oxygen gas flux, and moisture regain increased. As the treatment time increased, the etching rate increased first and then decreased. When the substrate was too close or too far from the nozzle, the etching rate was almost not measurable. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) show an increased surface roughness after the plasma treatment. X-ray photoelectron spectroscopy (XPS) shows a decreased carbon content and an increased oxygen content after the plasma treatment. T-peel strength shows an improved bonding strength between the PA 6 films and an adhesive tape after the plasma treatment.

  14. Influence of oxygen traces on an atmospheric-pressure radio-frequency capacitive argon plasma discharge

    International Nuclear Information System (INIS)

    An atmospheric-pressure capacitive discharge source driven by radio-frequency power supply at 13.56 MHz has been developed experimentally that is capable of producing a homogeneous and cold glow discharge in O2/Ar. With respect to the influence of oxygen component when diluted into argon plasma discharge on the discharge characteristics, the measurements of the electrical parameters (impedance, phase angle, resistance, and reactance) are made systematically and the densities of the metastable and resonant state of argon are determined by means of optical emission spectroscopy (OES). It is shown that the admixture of oxygen into argon plasma not only changes the electric characteristics but also alters the optical emission spectra greatly due to strong interaction between the oxygen content and the argon in the plasma environment.

  15. 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.

  16. Experimental evidence of imperfection influence on the buckling of thin cylindrical shell under uniform external pressure

    International Nuclear Information System (INIS)

    The load carrying behaviour of cylindrical thin-walled shell structures under pressure load is strongly dependent on the nature and magnitude of the imperfections invariably caused by various manufacturing processes. The present paper examines instabilities of long homogeneous and isotropic thin elastic tubes, characterized by geometric imperfections like eccentricity or ovality, on the buckling behaviour in conditions for which, at present, a complete theoretical analysis was not found in literature. Moreover, the additional aspect of the influence of the welded joint geometry and position is investigated over a wide range of diameter to thickness ratio, extending the findings of previous works. The problem of buckling for variable load conditions is relevant in the context of NPP applications as, for instance the optimisation of an integrated and innovative LWR Steam Generator (SG) tubes, according to the updated ASME rules. To the purpose, at Pisa University a rather intense research activity is being carried out on the buckling of thin walled metal specimens in the dimensional range suitable for the above mentioned application. Therefore a test equipment (with the necessary data acquisition facility), suitable for carrying out test series on this issue, as well as numerical models implemented on the MARC FEM code, were set up. The experiments were conducted on test specimens with different materials, e.g. A-316 ASTM (with and without seam weld) and Inconel 690 TT, as well as different loading conditions (lateral and hydrostatic external pressure). A validation of numerical evaluations by comparison with test results is also performed. A good agreement has been observed between the experimental data and the elasto-plastic finite element analyses results, highlighting also the different influence of the mentioned imperfections on the buckling loads

  17. Influence of the wetting state of a heated surface on heat transfer and pressure loss in an evaporator tube

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, W; Hein, D

    1986-09-01

    The influence of the wetting state of a heated surface on heat transfer and pressure loss in an evaporator tube was investigated for a parameter range occurring in fossil-fired steam generators. Included in the analysis are quantities which determine the wetting state in steady and transient flow. The experimental work consists of the following: Occurrence of critical heat flux (CHF) and post-CHF heat transfer in a vertical upflow evaporator tube; influence of pressure and enthalpy transients on heat transfer in the unwetted region; influence of pipe orientation on heat transfer; and two phase flow pressure loss in wetted and unwetted region. Based on these experiments a method of predicting CHF for a vertical upflow evaporator tube was developed. The heat transfer in the unwetted region was newly formulated taking into account thermal nonequilibrium between the water and steam phases. Wall temperature excursions during pressure and enthalpy transients are interpreted with the help of the boiling curve and the Leidenfrost phenomenon. A method is developed by means of which it is possible to determine the influence of the pipe orientation on the location of the boiling crisis as well as on the heat transfer in the unwetted region. The influence of the wetting state of the heated surface on the two phase flow pressure loss is interpreted as ''Wall effect'' and is calculated using a simplified computer model. 68 refs., 83 figs.

  18. Eosinophilic airway inflammation in COPD

    OpenAIRE

    Saha, Shironjit; Brightling, Christopher E.

    2006-01-01

    Chronic obstructive pulmonary disease is a common condition and a major cause of mortality. COPD is characterized by irreversible airflow obstruction. The physiological abnormalities observed in COPD are due to a combination of emphysema and obliteration of the small airways in association with airway inflammation. The predominant cells involved in this inflammatory response are CD8+ lymphocytes, neutrophils, and macrophages. Although eosinophilic airway inflammation is usually considered a f...

  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. Influence of effluent organic matter on copper speciation and bioavailability in rivers under strong urban pressure.

    Science.gov (United States)

    Matar, Z; Soares Pereira, C; Chebbo, G; Uher, E; Troupel, M; Boudahmane, L; Saad, M; Gourlay-France, C; Rocher, V; Varrault, Gilles

    2015-12-01

    This study focuses on spatiotemporal variations in the type of dissolved organic matter (DOM) and copper binding ability both upstream and downstream of Paris. It also compares the relative influence of both natural DOM upstream of Paris and effluent dissolved organic matter (EfDOM) output from a wastewater treatment plant (WWTP) on trace metal speciation and bioavailability in aquatic systems. In addition to the typical high- and low-affinity binding sites, a third family of very high-affinity binding sites has been highlighted for EfDOM. In receiving waters downstream of Paris during low-flow periods, the percentage of high- and very high-affinity sites originating from EfDOM reaches nearly 60 %. According to the speciation computation, the free copper concentration upstream of Paris exceeds the downstream Paris concentration by a factor of 2 to 4. As regards copper bioavailability, the highest EC50tot values were observed for EfDOM and downstream DOM, with a very low aromaticity and low UV absorbance. This finding suggests that specific ultraviolet absorbance (SUVA) is unlikely to be useful in assessing metal speciation and toxicity in aquatic systems subject to strong urban pressures. These results also highlight that the copper speciation computation for surface water exposed to considerable human pressures should include not only the humic and/or fulvic part of dissolved organic carbon but more hydrophilic fractions as well, originating for example from EfDOM. PMID:26257119

  1. Influence of high pressure hydrogen pre-exposure on crack growth under monotonic and cyclic loading

    International Nuclear Information System (INIS)

    Low alloy steels exposed to gaseous hydrogen atmospheres at high temperatures and pressures are prone to a mode of environmental degradation known as hydrogen attack, which occurs when carbon within the steel reacts with ingressed hydrogen to nucleate methane bubbles. In the present study, the role of such damage in influencing crack initiation/crack growth toughness and fatigue crack propagation behavior is examined in a highly susceptible Mn-Mi-Ni pressure vessel steel. It is shown that , whereas the fracture toughness and tearing modulus are severely degraded, even during the incubation stages of hydrogen attack, fatigue crack propagation rates are relatively unaffected. Such results are interpreted in terms of a mutual competition between microstructural damage generated by the grain boundary voids, which promotes crack growth, and the resulting tortuous crack paths and decarburization-induced softening, which can retard crack growth under cyclic loading. The degradation in toughness is related to changes in fracture ductility through consideration of a simple stress-modified critical strain model for microvoid coalescence. Fatigue behavior, conversely, is modeled in terms of the role of crack tip shielding in reducing the effective stress intensity range, locally experienced at the crack tip. Quantitative estimates of the magnitude of such shielding are derived using two dimensional models of crack deflection and roughness-induced crack closure

  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. Modeling the influence of the pulmonary pressure-volume curve on gas exchange.

    Science.gov (United States)

    Smith, Bram; Rees, Stephen; Tvorup, Jan; Christensen, Casper; Andreassen, Steen

    2005-01-01

    Current models of lung mechanics and gas exchange act independently to simulate variations in pressure-volume (PV) and ventilation-perfusion (V/Q) properties in the lungs respectively. However, changes in ventilator pressures can cause alveoli recruitment, collapse or over-distension causing V/Q changes in the lungs that are unaccounted for in these models. A compartmental model of the lungs is presented that is based on a physiological interpretation of lung function and simulates each alveolus individually. By combining this model with currently available lung mechanics and gas exchange models, the effect of changing ventilator settings on gas exchange could be simulated. The model is shown to simulate experimentally measured static PV data from an ARDS patient with an accuracy equivalent to that achieved by the sigmoid function. It could enable quantification of variations in V/Q in the lungs and also gives estimates of other physiological lung properties such as lung density and alveoli compliance. The alveoli model offers a physiologically relevant method of simulating the PV relationship in the lungs and its influence of gas exchange. PMID:17282708

  4. 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.

  5. Influence of dielectric materials on radial uniformity in non-equilibrium atmospheric pressure helium plasma

    Science.gov (United States)

    Oda, Akinori; Komori, Kyohei

    2015-09-01

    Non-equilibrium atmospheric pressure plasma has been utilized for various technological applications such as surface treatment, materials processing, bio-medical and bio-logical applications. For optimum control of the plasma for the above applications, numerous experimental and theoretical investigations on the plasma have been reported. Especially, controlling radial uniformity of the plasma are very important for utilizing materials processing. In this paper, an axially-symmetric three-dimensional fluid model, which is composed of the continuity equation for charged and neutral species, the Poisson equation, and the energy conservation equation for electrons, of non-equilibrium atmospheric pressure helium plasma has been developed. Then, influence of dielectric properties (e.g. relative permittivity, secondary electron emission coefficient, etc.) of dielectric materials on radial plasma uniformity (i.e. radial distributions of electron density, ion density, electric field in the plasma) was examined. This work was partly supported by KAKENHI (No. 26420247), and a ``Grant for Advanced Industrial Technology Development (No. 11B06004d)'' in 2011 from the New Energy and Industrial Technology Development Organization (NEDO) of Japan.

  6. Predictors of Airway Hyperresponsiveness in Elite Athletes

    DEFF Research Database (Denmark)

    Toennesen, Louise L; Porsbjerg, Celeste; Pedersen, Lars;

    2015-01-01

    INTRODUCTION: Elite athletes frequently experience asthma and airway hyperresponsiveness (AHR). We aimed to investigate predictors of airway pathophysiology in a group of unselected elite summer-sport athletes, training for the summer 2008 Olympic Games, including markers of airway inflammation...

  7. Influence of ethylene glycol pretreatment on effectiveness of atmospheric pressure plasma treatment of polyethylene fibers

    International Nuclear Information System (INIS)

    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. 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.

  9. Water permeability in human airway epithelium

    DEFF Research Database (Denmark)

    Pedersen, Peter Steen; Procida, Kristina; Larsen, Per Leganger;

    2005-01-01

    Osmotic water permeability (P(f)) was studied in spheroid-shaped human airway epithelia explants derived from nasal polyps by the use of a new improved tissue collection and isolation procedure. The fluid-filled spheroids were lined with a single cell layer with the ciliated apical cell membrane......(f), determined by the changes of the apical solution osmolarity, was not influenced by the presence of glucose, Na(+), or Na(+)/glucose-cotransport inhibitors in the bath, but was sensitive to the aquaporin (AQP) inhibitor HgCl(2). The measured P(f) levels and the values of activation energy were in the range...... of those seen in AQP-associated water transport. Together, these results indicate the presence of an AQP in the apical membrane of the spheroids. Notably, identical values for P(f) were found in CF and non-CF airway preparations, as was the case also for the calculated spontaneous fluid absorption rates....

  10. Influences of deposition rate and oxygen partial pressure on residual stress and microstructure of YSZ thin films

    International Nuclear Information System (INIS)

    Yttria-Stabilized Zirconia (YSZ) thin films were deposited on borosilicate crown glass substrates using electron beam evaporation technique and controlling technological parameters: deposition rate and oxygen partial pressure. Spectrophotometry, optical interferometry and X-ray diffraction were used to investigate how the thin film optical properties, residual stresses, and structure depend on these parameters. The results showed that the deposition rate had a significant influence on the increase of the refractive index of YSZ thin films while the oxygen partial pressure had less influence on it. In all samples, the tensile stress increased with the increasing of deposition rate and the decreasing of oxygen partial pressure. Meanwhile, all deposited films were poly-crystallizations, while crystallite size and preferential orientation of YSZ thin films changed as a function of deposition rate and oxygen partial pressure. The variations of the optical spectra and residual stress corresponded to the evolution of the film structures induced by the deposition parameters.

  11. 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

  12. 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 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.

  13. Where do winds come from? A new theory on how water vapor condensation influences atmospheric pressure and dynamics

    OpenAIRE

    Makarieva, A. M.; V. G. Gorshkov; D. Sheil; A. D. Nobre; B.-L. Li

    2013-01-01

    Phase transitions of atmospheric water play a ubiquitous role in the Earth's climate system, but their direct impact on atmospheric dynamics has escaped wide attention. Here we examine and advance a theory as to how condensation influences atmospheric pressure through the mass removal of water from the gas phase with a simultaneous account of the latent heat release. Building from fundamental physical principles we show that condensation is associated with a decline in air pressure in t...

  14. Where do winds come from? A new theory on how water vapor condensation influences atmospheric pressure and dynamics

    OpenAIRE

    Makarieva, A. M.; V. G. Gorshkov; D. Sheil; A. D. Nobre; B.-L. Li

    2010-01-01

    Phase transitions of atmospheric water play a ubiquitous role in the Earth's climate system, but their direct impact on atmospheric dynamics has escaped wide attention. Here we examine and advance a theory as to how condensation influences atmospheric pressure through the mass removal of water from the gas phase with a simultaneous account of the latent heat release. Building from fundamental physical principles we show that condensation is associated with a decline in air pressure in t...

  15. Airways Disease: Phenotyping Heterogeneity Using Measures of Airway Inflammation

    Directory of Open Access Journals (Sweden)

    Siddiqui Salman

    2007-06-01

    Full Text Available Despite asthma and chronic obstructive pulmonary disease being widely regarded as heterogeneous diseases, a consensus for an accurate system of classification has not been agreed. Recent studies have suggested that the recognition of subphenotypes of airway disease based on the pattern of airway inflammation may be particularly useful in increasing our understanding of the disease. The use of non-invasive markers of airway inflammation has suggested the presence of four distinct phenotypes: eosinophilic, neutrophilic, mixed inflammatory and paucigranulocytic asthma. Recent studies suggest that these subgroups may differ in their etiology, immunopathology and response to treatment. Importantly, novel treatment approaches targeted at specific patterns of airway inflammation are emerging, making an appreciation of subphenotypes particularly relevant. New developments in phenotyping inflammation and other facets of airway disease mean that we are entering an era where careful phenotyping will lead to targeted therapy.

  16. The phenomenon of social influence on the football pitch: Social pressure from the crowd on referees’ decisions

    OpenAIRE

    Di Corrado, Donatella; Pellarin, Elena; Agostini, Tiziano Alessandro

    2011-01-01

    In most areas of society, the phenomenon of social pressure on the behaviour of individuals has always played a critical role and affects the outcome of important events. One of the environments in which the phenomenon of social influence and pressure is most evident is sport: the preferences of a particular group, the crowd at a football match, can in fact greatly influence the referee’s behaviour and decisions. In this paper, we will report a brief summary of the literature about the social...

  17. 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.

  18. Hydroformylation of Cyclohexene with Carbon Dioxide and Hydrogen Using Ruthenium Carbonyl Catalyst: Influence of Pressures of Gaseous Components

    OpenAIRE

    Masahiko Arai; Yoshinari Akiyama; Shuhei Okamura; Shin-ichiro Fujita

    2007-01-01

    Hydroformylation of cyclohexene was studied with a catalyst system of Ru3(CO)12 and LiCl using H2 and CO2 instead of CO in NMP. The influence of H2 and CO2 pressures on the total conversion and the product distribution was examined. It was shown that increasing total pressure of H2 and CO2 promoted the reverse water gas shift reaction and increased the yield of cyclohexanecarboxaldehyde. Its hydrogenation to cyclohexanemethanol was promoted with increasing H2 pressure but suppressed with incr...

  19. Influence of Oxygen Partial Pressure on the Fermi Level of ZnO Films Investigated by Kelvin Probe Force Microscopy

    International Nuclear Information System (INIS)

    The influence of oxygen partial pressure on the Fermi level of ZnO films prepared by pulsed laser deposition is investigated. The contact potential difference of the ZnO films fabricated under various oxygen partial pressures is studied systematically using Kelvin probe force microscopy. The Fermi level shifted by 0.35 eV as oxygen partial pressure increased. This indicates a significant change in the electronic structure and energy balance in ZnO films. This fact provides a consistent explanation that the changes in carrier concentration, resistivity and mobility of ZnO films are attributed to oxygen vacancy induced shift of the Fermi level

  20. Influence of Oxygen Partial Pressure on the Fermi Level of ZnO Films Investigated by Kelvin Probe Force Microscopy

    Science.gov (United States)

    Su, Ting; Zhang, Hai-Feng

    2012-12-01

    The influence of oxygen partial pressure on the Fermi level of ZnO films prepared by pulsed laser deposition is investigated. The contact potential difference of the ZnO films fabricated under various oxygen partial pressures is studied systematically using Kelvin probe force microscopy. The Fermi level shifted by 0.35 eV as oxygen partial pressure increased. This indicates a significant change in the electronic structure and energy balance in ZnO films. This fact provides a consistent explanation that the changes in carrier concentration, resistivity and mobility of ZnO films are attributed to oxygen vacancy induced shift of the Fermi level.

  1. Airway emergencies in cancer

    Directory of Open Access Journals (Sweden)

    Patil Vijaya

    2007-01-01

    Full Text Available Management of airway obstruction is always challenging but more so in cancer setting, as obstruction can lie at any level right from pyriform fossa to low down in medistinum. Morbidity is significant but if not managed properly leads to frightful death by suffocation. These cases need to be evaluated, diagnosed and managed with care, skill, speed and appropriate intervention. With the advent of technology, it has become much easier to manage such situations with a team of specialists involving anesthetist, thoracic surgeon and intensivist.

  2. 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.

  3. Paediatric airway management: basic aspects

    DEFF Research Database (Denmark)

    Holm-Knudsen, R J; Rasmussen, L S

    2009-01-01

    children. This paper aims at providing the non-paediatric anaesthesiologist with a set of safe and simple principles for basic paediatric airway management. In contrast to adults, most children with difficult airways are recognised before induction of anaesthesia but problems may arise in all children...

  4. The influence of self-owned home blood pressure monitoring (HBPM) on primary care patients with hypertension: A qualitative study

    OpenAIRE

    Abdullah Adina; Othman Sajaratulnisah

    2011-01-01

    Abstract Background Home blood pressure monitoring (HBPM) is gaining popularity among hypertensive patients. This study aimed to explore the influence of self-initiated HBPM on primary care patients with hypertension. Methods Six in-depth interviews and two focus group discussions were conducted, taking into consideration the experiences of 24 primary care patients with hypertension. These patients had been using HBPM as part of their hypertension management. The overriding influences were gr...

  5. Research of radiation pressure and Poynting–Robertson effect influence on geodesic artificial satellites and space debris motion.

    OpenAIRE

    Nikolay A. Sorokin; Elena N. Kablova

    2013-01-01

    During space colonization it will be inevitably precision navigation using, that requires non-gravitational effects precise accounting. One of these effects mathematical description - radiation pressure with concomitant Poynting–Robertson effect influence on space objects as artificial satellites and space debris - is examined in this article. Satellite motion is accompanied by the Sun illuminance, with short-time operations in the Earth penumbra and umbra, that influence satellites orbit e...

  6. Influence of atmospheric pressure plasma treatment on surface properties of PBO fiber

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ruiyun; Pan Xianlin [Key Laboratory of Textile Science and Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620 (China); Jiang Muwen [Key Laboratory of Science and Technology of Eco-Textile, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620 (China); Peng Shujing [Key Laboratory of Textile Science and Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620 (China); Qiu Yiping, E-mail: ypqiu@dhu.edu.cn [Key Laboratory of Science and Technology of Eco-Textile, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer PBO fibers were treated with atmospheric pressure plasmas. Black-Right-Pointing-Pointer When 1% of oxygen was added to the plasma, IFSS increased 130%. Black-Right-Pointing-Pointer Increased moisture regain could enhance plasma treatment effect on improving IFSS with long treatment time. - Abstract: In order to improve the interfacial adhesion property between PBO fiber and epoxy, the surface modification effects of PBO fiber treated by atmospheric pressure plasma jet (APPJ) in different time, atmosphere and moisture regain (MR) were investigated. The fiber surface morphology, functional groups, surface wettability for control and plasma treated samples were analyzed by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements, respectively. Meanwhile, the fiber interfacial shear strength (IFSS), representing adhesion property in epoxy, was tested using micro-bond pull-out test, and single fiber tensile strength was also tested to evaluate the mechanical performance loss of fibers caused by plasma treatment. The results indicated that the fiber surface was etched during the plasma treatments, the fiber surface wettability and the IFSS between fiber and epoxy had much improvement due to the increasing of surface energy after plasma treatment, the contact angle decreased with the treatment time increasing, and the IFSS was improved by about 130%. The processing atmosphere could influence IFSS significantly, and moisture regains (MR) of fibers also played a positive role on improving IFSS but not so markedly. XPS analysis showed that the oxygen content on fiber surface increased after treatment, and C=O, O-C=O groups were introduced on fiber surface. On the other hand, the observed loss of fiber tensile strength caused by plasma treatment was not so remarkable to affect the overall performance of composite materials.

  7. Influence of atmospheric pressure plasma treatment on surface properties of PBO fiber

    International Nuclear Information System (INIS)

    Highlights: ► PBO fibers were treated with atmospheric pressure plasmas. ► When 1% of oxygen was added to the plasma, IFSS increased 130%. ► Increased moisture regain could enhance plasma treatment effect on improving IFSS with long treatment time. - Abstract: In order to improve the interfacial adhesion property between PBO fiber and epoxy, the surface modification effects of PBO fiber treated by atmospheric pressure plasma jet (APPJ) in different time, atmosphere and moisture regain (MR) were investigated. The fiber surface morphology, functional groups, surface wettability for control and plasma treated samples were analyzed by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements, respectively. Meanwhile, the fiber interfacial shear strength (IFSS), representing adhesion property in epoxy, was tested using micro-bond pull-out test, and single fiber tensile strength was also tested to evaluate the mechanical performance loss of fibers caused by plasma treatment. The results indicated that the fiber surface was etched during the plasma treatments, the fiber surface wettability and the IFSS between fiber and epoxy had much improvement due to the increasing of surface energy after plasma treatment, the contact angle decreased with the treatment time increasing, and the IFSS was improved by about 130%. The processing atmosphere could influence IFSS significantly, and moisture regains (MR) of fibers also played a positive role on improving IFSS but not so markedly. XPS analysis showed that the oxygen content on fiber surface increased after treatment, and C=O, O-C=O groups were introduced on fiber surface. On the other hand, the observed loss of fiber tensile strength caused by plasma treatment was not so remarkable to affect the overall performance of composite materials.

  8. The prevalence and influence factors of inter-ankle systolic blood pressure difference in community population.

    Directory of Open Access Journals (Sweden)

    Zhihong Zhang

    Full Text Available AIM: The aim of this study was to investigate the prevalence of interankle systolic blood pressure difference (sIAND and its influencing factors in community population. METHODS: This study included 2849 (65.1±9.4 y subjects. Blood pressure (BPs of four limbs was simultaneously measured with 4 electronic sphygmomanometers after 10 min rest in supine position. The difference of systolic BP (SBP between two ankles was calculated as DETASBP. The criterion for abnormal sIAND was ≥10 mmHg of absolute DeltaSBP, in which the criterion for 1o sIAND was 10-19 mmHg and for 2o sIAND was ≥20 mmHg. Age, gender, smoking, hypertension, family histories of hypertension and diabetes were recorded. Fasting blood glucose and lipids, circumference of hip and waist, and body mass index (BMI were measured. RESULTS: The SBP was higher in the right ankle than in the left ankle (158.9±21.8 vs 157.3±21.6 mmHg, P<0.05 and mean DeltaSBP was 6.08±6.26 mmHg. Similar difference was found in both genders. The prevalence of abnormal was 18.5%, in which, the prevalence 1o sIAND was 15.3% and that of 2o sIAND was 3.1%. Multivariate regression analysis showed that age, waist circumference and blood glucose level were the positive factors for DeltaSBP. The normal upper limit for DeltaSBP was 16.7 mmHg in this population, the prevalence of sIAND by≥16 mmHg was 5.8%. CONCLUSION: Aging, hypertension, obesity and abnormal glucose metabolism are positive factors for inter-ankle SBP difference.

  9. Compactation pressure influence on the thermophysical properties of uranium dioxide fuel pellets produced with kernels

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Ricardo Alberto Neto; Andrade, Antonio Santos; Miranda, Odair; Grossi, Pablo Andrade; Camarano, Denise das Merces; Migliorini, Fabricio Lima; Silva, Egonn Hendrigo Carvalho; Andrade, Roberto Marcio de [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)], e-mail: ranf@cdtn.br, e-mail: antdrade@gmail.com, e-mail: odairm@cdtn.br, e-mail: pabloag@cdtn.br, e-mail: dmc@cdtn.br, e-mail: flmigliorini@hotmail.com, e-mail: egonn@ufmg.br

    2009-07-01

    Under compaction pressures ranging from 300 MPa up to 500 MPa, fuel pellets of uranium dioxide were manufactured by the pressing of kernels. These were produced by the sol-gel process developed in Germany by NUKEM for using in high temperature gas cooled reactors, which were absorbed, transferred and implanted at CDTN-Centro de Desenvolvimento da Tecnologia Nuclear. The sintering was performed at 1700 deg C for two hours under argon with 4% hydrogen atmosphere, resulting sintered densities ranging from 9.33 g{center_dot}cm{sup -3} up to 10.08 g{center_dot}cm{sup -3}, determined by the xylol penetration-immersion method. Using the flash laser method, the thermophysical properties of the pellets were determined and thermal diffusivity ranging from 2.58 x 10{sup -6}m{sup 2}{center_dot}s{sup -1} up to 2.78 x 10{sup -6}m{sup 2}{center_dot}s{sup -1} and thermal conductivity from 6.22 m{sup -1}{center_dot}K{sup -1} up to 7.24 W{center_dot}m{sup -1}{center_dot}K{sup -1}, corresponding to a decreasing of the porosity from 14.88% to 8.05%. The methodology is described and the influence of the compaction pressure on the pellet properties is also analyzed. The thermal conductivity results of this study will be very valuable to a project in development at CDTN, in which uranium dioxide pellets will be produced by the pressing of kernels, with beryllium oxide filling the voids between the kernels in order to enhance the thermal conductivity of the fuel and consequently, the thermal performance of the fuel rod, as required in extended burnup conditions. They will be used as reference to compare and calculate the favorable increase of the thermal conductivity, caused by the addition of beryllium oxide. (au0010th.

  10. Compactation pressure influence on the thermophysical properties of uranium dioxide fuel pellets produced with kernels

    International Nuclear Information System (INIS)

    Under compaction pressures ranging from 300 MPa up to 500 MPa, fuel pellets of uranium dioxide were manufactured by the pressing of kernels. These were produced by the sol-gel process developed in Germany by NUKEM for using in high temperature gas cooled reactors, which were absorbed, transferred and implanted at CDTN-Centro de Desenvolvimento da Tecnologia Nuclear. The sintering was performed at 1700 deg C for two hours under argon with 4% hydrogen atmosphere, resulting sintered densities ranging from 9.33 g·cm-3 up to 10.08 g·cm-3, determined by the xylol penetration-immersion method. Using the flash laser method, the thermophysical properties of the pellets were determined and thermal diffusivity ranging from 2.58 x 10-6m2·s-1 up to 2.78 x 10-6m2·s-1 and thermal conductivity from 6.22 m-1·K-1 up to 7.24 W·m-1·K-1, corresponding to a decreasing of the porosity from 14.88% to 8.05%. The methodology is described and the influence of the compaction pressure on the pellet properties is also analyzed. The thermal conductivity results of this study will be very valuable to a project in development at CDTN, in which uranium dioxide pellets will be produced by the pressing of kernels, with beryllium oxide filling the voids between the kernels in order to enhance the thermal conductivity of the fuel and consequently, the thermal performance of the fuel rod, as required in extended burnup conditions. They will be used as reference to compare and calculate the favorable increase of the thermal conductivity, caused by the addition of beryllium oxide. (author)

  11. 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.

  12. 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

  13. Airway Strain during Mechanical Ventilation in an Intact Animal Model

    OpenAIRE

    Sinclair, Scott E.; Molthen, Robert C.; Haworth, Steve T.; Dawson, Christopher A.; Waters, Christopher M.

    2007-01-01

    Rationale: Mechanical ventilation with large tidal volumes causes ventilator-induced lung injury in animal models. Little direct evidence exists regarding the deformation of airways in vivo during mechanical ventilation, or in the presence of positive end-expiratory pressure (PEEP).

  14. Effects of age and gender on upper airway, lower airway and upper lip growth

    OpenAIRE

    Renata de Cassia Gonçalves; Dirceu Barnabé Raveli; Ary dos Santos Pinto

    2011-01-01

    The aim of the present retrospective study was to evaluate the influence of age and gender on upper and lower airway width and upper lip length. In this study, 390 lateral cephalograms were divided into 13 age groups (ranging from 6 to 18 years) and were analyzed. The intergroup differences were analyzed using a MANOVA (Multivariate Analysis of the Variance), and the intragroup differences were analyzed using an ANOVA (Analysis of the Variance) and Tukey's test. The results of the present stu...

  15. 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

  16. The influence of various pressures in pneumatic tyre on braking process of car with anti-lock braking system

    Directory of Open Access Journals (Sweden)

    Damian HADRYŚ

    2008-01-01

    Full Text Available In this article has been presented the influence of various pressures inpneumatic tyre of passenger car Fiat Panda 1.3 JTD with anti-lock braking system on chosen parameters of braking process: course of braking deceleration, maximum value of deceleration, braking distances.

  17. Intraocular pressure and influencing systemic health parameters in a Korean population

    Directory of Open Access Journals (Sweden)

    Young Sang Han

    2014-01-01

    Full Text Available Aim: To evaluate the relationship between intraocular pressure (IOP and systemic health parameters such as age, gender, body mass index (BMI, total cholesterol, high density lipoprotein (HDL, and triglyceride (TG in a Korean population. Materials and Methods: A total of 30,893 healthy subjects underwent automated multiphasic tests, including non-contact tonometry, automated perimetry, fundus photography, and blood samplings for total cholesterol, HDL, and TG. Seven age groups were divided by decades ranging from 20 to 29 years to 80 + years. The association between IOP and BMI, plasma lipid profiles was examined using cross-sectional analysis. Results: The mean age of subjects was 47.7 years. The mean IOP of subjects was 15.4 ± 3.2 mmHg for both eyes. The mean IOP of men was significantly higher than women ( P = 0.000. By multiple linear regression analysis, IOP was positively associated with gender (male, BMI, total cholesterol, and TG and negatively associated with age ( P = 0.000. BMI, total cholesterol, and TG had significantly positive correlations with IOP after adjusting for age, gender, and other variables which can influence the IOP ( P = 0.000. Conclusions: In a Korean population, the mean IOP, total cholesterol, TG, and BMI values of men were higher than women. IOP was found to increase with total cholesterol, TG, BMI, and to decrease with only age regardless of sex.

  18. Neutral interstellar hydrogen in the inner heliosphere under influence of wavelength-dependent solar radiation pressure

    CERN Document Server

    Tarnopolski, S

    2007-01-01

    We study the influence of the non-flat shape of the solar Lyman-alpha line on the distribution of neutral interstellar hydrogen in the inner heliosphere, assess importance of this effect for interpretation of heliospheric measurements. Based on available data, we construct a model of evolution of the solar Lyman-alpha line profile with solar activity. Modify existing test-particle code calculating distribution of neutral interstellar hydrogen in the inner heliosphere to take into account the dependence of radiation pressure on radial velocity. Discrepancies between the classical and Doppler models appear at ~ 10 AU and increase towards the Sun from a few percent to a factor of 2 at 1 AU. The classical model overestimates density everywhere except a ~ 60 deg cone around the downwind direction, where a density deficit appears. The magnitude of discrepancies depends appreciably on the phase of solar cycle, but only weakly on the parameters of the gas at the termination shock. The intensity of backscatter radiati...

  19. Influence of ethanol-amine injection on flow accelerated corrosion rate in pressurized water reactor

    International Nuclear Information System (INIS)

    Some pressurized water reactor (PWR) plants have introduced ethanol-amine (ETA) injection for the purpose of decreasing iron transfer in steam generator (SG). The ETA injection is supposed to decrease flow accelerated corrosion (FAC) rate, because of secondary system pH increase. But the water chemistry in the secondary system is very complicated. So water chemistry following ETA injection and the effect of ETA injection on FAC rate have not been studied systematically. To assess the influence of ETA injection on FAC rate, it is assumed that the model of FAC rate is proportional to the concentration gradient of magnetite. Then chemical concentration and magnetite solubility of the secondary system are calculated and the change of FAC rate is evaluated in the outline. It has been clarified that the effect of ETA injection reduces the FAC rate to about 1/3-1/22 of that of ammonia. In some portions of the secondary system, the effects of ETA injection have been measured experimentally by rotary disk test. The FAC rate of ETA injection is larger than that of ammonia at high temperature. And the FAC rate peaks at about 180degC in the case of ammonia, but the peak seems to shift to higher temperatures in the case of ETA. (author)

  20. Influence of ethanol-amine injection on flow accelerated corrosion rate in pressurized water reactor

    International Nuclear Information System (INIS)

    Some pressurized water reactor (PWR) plants have introduced ethanol-amine (ETA) injection for the purpose of decreasing iron transfer in the steam generator (SG). The ETA injection is supposed to decrease the rate of flow accelerated corrosion (FAC) by increasing the pH of the secondary system. However, the water chemistry in the secondary system is very complicated and so water chemistry following ETA injection and the effect of ETA injection on FAC rate have not been studied systematically. To assess the influence of ETA injection on FAC rate, we use a model that assumes the FAC rate is proportional to the concentration gradient of magnetite. We then calculate the chemical concentration and magnetite solubility of the secondary system and approximately evaluate the change of FAC rate. It is shown that ETA injection reduces the FAC rate to about 1/3 - 1/22 of that of ammonia. In some portions of the secondary system, we also measured the effects of ETA injection experimentally by rotating disk test, and found that the FAC rate decreases under ETA conditions. The peak FAC rate shifted to a higher temperature after ETA injection. At 274degC, the FAC rates are nearly the same under the conditions of high pH of ETA and low pH of ammonia. (author)

  1. [The influence of low partial oxygen pressure on the biolodical process of mesenchymal stromal cells].

    Science.gov (United States)

    Berezovskyĭ, V Ia; Plotnikova, L M; Vesel'skyĭ, S P; Litovka, I H

    2014-01-01

    The influence of low partial oxygen pressure (Po2) on the amino acid composition in culture medium of human mesenchymal stromal cell (MSC) lines 4BL has been studied. At 23 mm Hg (3% oxygen), a significant decrease (by 31%) in the concentration of proline and hydroxyproline was registered. Under these conditions, the concentration of serine and aspartic acid decreased by 45% compared to the control. Maximum consumption of free amino acids from the culture medium required for the synthesis of collagen (proline and hydroxyproline by 42%, serine and aspartic acid by 62%) was observed at a gas-phase Po2 of 38 mm Hg (5% O2). At Po2 76 mm Hg (10% O2), a lack of amino acids proline and hydroxyproline was only 21%, while that of glutamine and alanine amounted 12% compared to the control. This intensity ratio of consumption of amino acids may indicate that the maximum of MSC vital functions occurs at Po2 38 mm Hg. PMID:25095672

  2. Influence of phosphorus content of coconut oil on deposit and performance of plant oil pressure stoves

    Energy Technology Data Exchange (ETDEWEB)

    Kratzeisen, M.; Mueller, J. [Institut fuer Agrartechnik, Universitaet Hohenheim (440e), Garbenstrasse 9, D-70593 Stuttgart (Germany)

    2010-11-15

    Influence of phosphorus lipids on formation of deposits and performance of plant oil pressure stoves was investigated. Refined coconut oil with an original phosphorous content of 5.9 mg/kg was used as base for fuel blends by adding lecithin to adjust increased phosphorous concentrations of 32.2, 51.6 and 63.0 mg/kg. The fuel blends were analysed for acid value, iodine value, total contamination, ash content and Conradson carbon residue according to standard methods. In burning trials, the specific fuel consumption, the required frequency of nozzle cleaning and the amount of deposits in the vaporizer were measured. Results showed an exponential increase of deposits in the vaporizer when phosphorous content was increased: deposits amounted to 0.12 g/kg of consumed fuel for unblended coconut oil and 0.92 g/kg for the blend with the highest phosphorous content. Furthermore, increased phosphorous content caused higher fuel consumption of 0.375 kg/h compared to 0.316 kg/h for the control. (author)

  3. Pressures at larger spatial scales strongly influence the ecological status of heavily modified river water bodies in Germany.

    Science.gov (United States)

    Kail, Jochem; Wolter, Christian

    2013-06-01

    River biota are influenced by anthropogenic pressures that operate at different spatial scales. Understanding which pressures at which spatial scales affect biota is essential to manage and restore degraded rivers. In Europe, many river reaches were designated as Heavily Modified Water Bodies (HMWB) according to the European Water Framework Directive (WFD), where the ecological potential might mainly be determined by pressures at larger spatial scales outside the HMWB (e.g. hydromorphological alterations at the river network and land use at the catchment scale). In Germany, hydromorphological alterations and diffuse pollution were the main pressures. Therefore, the three objectives of this study were to (i) identify the hydromorphological pressures at the site, reach, and river network scale, and land use categories at the catchment scale which significantly affect the ecological status of HMWB in Germany, (ii) quantify the relative importance of these pressures at different spatial scales, and (iii) analyse the differences in response between fish and macroinvertebrates. The results indicated that: (i) At the reach scale, fish were most strongly influenced by channel-bank conditions whilst the naturalness of channel-planform was the best proxy for the ecological status of macroinvertebrates. At the catchment scale, urbanization was the most detrimental land use. (ii) The pressures at larger spatial scales (catchment land use and hydromorphological alterations in the river network) generally were more important than hydromorphological alterations at the reach scale. (iii) Fish were affected equally by both, hydromorphological alterations at the reach scale and large-scale pressures whereas the latter were far more important for the ecological status of macroinvertebrates. In conclusion, these results indicated that large-scale pressures may often limit the efficiency of reach-scale restoration, especially for macroinvertebrates, even in the absence of saprobic

  4. 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.

  5. Computed tomography dose and variability of airway dimension measurements: how low can we go?

    International Nuclear Information System (INIS)

    Quantitative CT shows promise as an outcome measure for cystic fibrosis (CF) lung disease in infancy, but must be accomplished at a dose as low as reasonably achievable. To determine the feasibility of ultra-low-dose CT for quantitative measurements of airway dimensions. Two juvenile pigs were anesthetized and their lungs scanned at 25 cm H2O face-mask pressure in apnoea using beam currents of 5, 10, 20, 40 and 100 mAs. The lumen diameters and wall thicknesses of matched airways (n=22) at each dose were measured by two observers using validated software. Measurement variability at each dose was compared to that at 100 mAs (reference dose) for large and small airways (lumen diameter <2.5 mm). Lowering CT dose (mAs) affected measurement variability for lumen diameter of small and large airways (P<0.001) and for wall thickness of small (P<0.001), but not large (P=0.63), airways. To obtain the same measurement variability at 5 mAs as at 100 mAs, four to six small airways or one to three large airways have to be measured and averaged. Quantitative airway measurements are feasible on images obtained at as low as 5 mAs, but more airways need to be measured to compensate for greater measurement variability. (orig.)

  6. Relationship between upper airway obstruction and gastroesophageal reflux in a dog model.

    Science.gov (United States)

    Boesch, Richard Paul; Shah, Prashant; Vaynblat, Mikhail; Marcus, Michael; Pagala, Murali; Narwal, Shivinder; Kazachkov, Mikhail

    2005-01-01

    The association between gastroesophageal reflux (GER) and upper airway obstruction in children is recognized but not well understood. Our objective was to determine if the creation of a model of upper airway obstruction in dogs would cause GER and to determine if the GER is related to intrathoracic pressure changes. Five dogs underwent evaluation with esophageal manometry and pH probe at baseline and 1 week after creation of an upper airway obstruction. Airway obstruction was created by placement of a fenestrated cuffed tracheostomy tube, which was then capped and the cuff was inflated, requiring the animals to breathe via the fenestrations. The negative inspiratory pressure (Pes) (+/- SD) increased from 11.8 +/- 4.8 cm H(2)O at baseline to 17.6 +/- 4.9 cm H(2)O 1 week after creation of an airway obstruction (p = .029). None of the dogs had GER at baseline with a reflux index (RI) value of 0.0; however, 1 week after creation of airway obstruction, three out of five dogs had GER, with a mean RI value of 21.2 +/- 21.2. There was a significant (p = .023) correlation (r = .928) of the changes in Pes and RI values following airway obstruction. Upper airway obstruction (UAO) does cause GER in this canine model. Severity of GER is significantly correlated with Pes changes. PMID:16249167

  7. Influence of the homogenization pressure on the ice cream mix quality

    OpenAIRE

    Iva Murgić; Rajka Božanić

    2008-01-01

    In this paper the suitability of different homogenization pressures on appearance and quality of ice cream mix was determined. The ice cream mix were taken from ageing tank, and depending on the source of fat in ice cream mix (butter, vegetable fat or cream) they were homogenized under different pressures. Afterwards, by microscope with scalar, fat globule size was determined. The homogenization pressures reduce the fat globule size to 1-2 μm without clumping and these pressures have been cha...

  8. How male sound pressure level influences phonotaxis in virgin female Jamaican field crickets (Gryllus assimilis)

    OpenAIRE

    Karen Pacheco; Bertram, Susan M.

    2014-01-01

    Understanding female mate preference is important for determining the strength and direction of sexual trait evolution. The sound pressure level (SPL) acoustic signalers use is often an important predictor of mating success because higher sound pressure levels are detectable at greater distances. If females are more attracted to signals produced at higher sound pressure levels, then the potential fitness impacts of signalling at higher sound pressure levels should be elevated beyond what woul...

  9. Plethysmographic measurements of specific airway resistance in young children

    DEFF Research Database (Denmark)

    Bisgaard, Hans; Nielsen, Kim G

    2005-01-01

    Validated methods for lung function measurements in young children are lacking. Plethysmographic measurement of specific airway resistance (sRaw) provides such a method applicable from 2 years of age. sRaw gauges airway resistance from the measurements of the pressure changes driving the airflow...... also been documented by this technique, and sRaw has recently been used in longitudinal studies of young children with chronic pulmonary diseases. Future developments should provide improved algorithms for thermal correction of the respired volumes and adapt the equipment to the special needs of young...

  10. Neutrophils mediate airway hyperresponsiveness after chlorine-induced airway injury in the mouse.

    Science.gov (United States)

    McGovern, Toby K; Goldberger, Madison; Allard, Benoit; Farahnak, Soroor; Hamamoto, Yoichiro; O'Sullivan, Michael; Hirota, Nobuaki; Martel, Guy; Rousseau, Simon; Martin, James G

    2015-04-01

    Chlorine gas (Cl2) inhalation causes oxidative stress, airway epithelial damage, airway hyperresponsiveness (AHR), and neutrophilia. We evaluated the effect of neutrophil depletion on Cl2-induced AHR and its effect on the endogenous antioxidant response, and if eosinophils or macrophages influence Cl2-induced AHR. We exposed male Balb/C mice to 100 ppm Cl2 for 5 minutes. We quantified inflammatory cell populations in bronchoalveolar lavage (BAL), the antioxidant response in lung tissue by quantitative PCR, and nuclear factor (erythroid-derived 2)-like 2 (NRF2) nuclear translocation by immunofluorescence. In vitro, NRF2 nuclear translocation in response to exogenous hypochlorite was assessed using a luciferase assay. Anti-granulocyte receptor-1 antibody or anti-Ly6G was used to deplete neutrophils. The effects of neutrophil depletion on IL-13 and IL-17 were measured by ELISA. Eosinophils and macrophages were depleted using TRFK5 or clodronate-loaded liposomes, respectively. AHR was evaluated with the constant-phase model in response to inhaled aerosolized methacholine. Our results show that Cl2 exposure induced neutrophilia and increased expression of NRF2 mRNA, superoxide dismutase-1, and heme-oxygenase 1. Neutrophil depletion abolished Cl2-induced AHR in large conducting airways and prevented increases in antioxidant gene expression and NRF2 nuclear translocation. Exogenous hypochlorite administration resulted in increased NRF2 nuclear translocation in vitro. After Cl2 exposure, neutrophils occupied 22 ± 7% of the luminal space in large airways. IL-17 in BAL was increased after Cl2, although this effect was not prevented by neutrophil depletion. Neither depletion of eosinophils nor macrophages prevented Cl2-induced AHR. Our data suggest the ability of neutrophils to promote Cl2-induced AHR is dependent on increases in oxidative stress and occupation of luminal space in large airways. PMID:25192041

  11. Airway and lung parenchyma morphology during the respiratory cycle

    OpenAIRE

    Escolar Castellón, J.de D.; Escolar, M.A.; Blasco, J; Ros, L.H.

    2007-01-01

    Objective: Describe the morphological changes that take place in the lung parenchyma and in the airways during the respiratory cycle with a view to establishing a relationship between them. Subjects: Adult Wistar rats. Interventions: The lungs were fixed at seven different points in the respiratory cycle: Inflation, 10 and 20 cm. transpulmonary pressure, total lung capacity. Deflation, 20, 15, 10 and 0 cm transpulmonary pressure. Measurements: The lungs were pr...

  12. 持续正压呼吸机压力发生器内部流场的数值模拟%The Numerical Simulation of the Internal Flow Field inside the Pressure Generator of a Continuous Positive Airway Pressure Ventilator

    Institute of Scientific and Technical Information of China (English)

    程云章; 朱莉花; 张伟国; 吴文权

    2011-01-01

    呼吸机的噪声问题一直是呼吸机发展至今重点研究的课题.众多资料表明,在呼吸机的噪声控制上,国内与国外先进水平相比仍有较大差距.本文与上海医疗设备股份有限公司合作,应用专业的计算流体动力学(CFD)软件FLUENT,选取标准k-ε湍流方程模型和SIMPLE算法,对家用持续气道正压(CPAP)呼吸机的压力发生器内部流场进行数值模拟,并对模拟结果进行分析讨论.结果表明,该CPAP呼吸机压力发生器蜗壳部分有局部回流现象,叶轮部分流场速度出现局部不均匀,叶轮进口处存在局部负压,易导致噪声产生,影响整机性能,因此其设计有待改进.%The problem of noise in ventilator has always been an important topic to study in the development of the ventilator. A great number of data are showing that there are still large gaps of research and application levels in noise control of the ventilator between China and some more advanced foreign countries. In this study, with cooperation of the Shanghai Medical Equipment Limited Liability Company, we used the computational fluid dynamics (CFD), software FLUENT, adopted the standard k-e turbulence model and the SIMPLE algorithm to simulate the inner flow field of the continuous positive airway pressure (CPAP) ventilator's pressure generator. After a detailed analysis, we figured out that there are several deficiencies in this ventilator, like local reflow in volute, uneven velocity distribution and local negative pressure in inlet of the impeller, which easily lead to noise and affect the ventilator' s performances. So. It needs to be improved to a certain extent.

  13. Numerical simulation of the influence of distributor pitch diameter on performance and pressure fluctuations in a pump-turbine

    International Nuclear Information System (INIS)

    In order to analyse the influence of distributor pitch diameter on performance and pressure fluctuations in a pump turbine, a numerical model based on a pumped storage power station was built to develop the numerical simulation. Steady and unsteady flows were simulated using the SST k-ω turbulence model and SIMPLEC Pressure-Velocity coupling scheme. The performance, inner flow and pressure fluctuations between runner blades and guide vanes of both turbine and pump mode was contrasted in different distributor pitch diameters. The result shows there was a maximum total efficiency in a given distributor pitch diameter instead of the design diameter. Amplitudes and frequencies of pressure fluctuations on this diameter and design diameter were analysed, minor differences were observed. This position can be considered to help improving the flow of the pump turbine.

  14. Numerical simulation of the influence of distributor pitch diameter on performance and pressure fluctuations in a pump-turbine

    Science.gov (United States)

    Sun, Y. K.; Zuo, Z. G.; Liu, S. H.; Wu, Y. L.; Liu, J. T.

    2012-11-01

    In order to analyse the influence of distributor pitch diameter on performance and pressure fluctuations in a pump turbine, a numerical model based on a pumped storage power station was built to develop the numerical simulation. Steady and unsteady flows were simulated using the SST k-ω turbulence model and SIMPLEC Pressure-Velocity coupling scheme. The performance, inner flow and pressure fluctuations between runner blades and guide vanes of both turbine and pump mode was contrasted in different distributor pitch diameters. The result shows there was a maximum total efficiency in a given distributor pitch diameter instead of the design diameter. Amplitudes and frequencies of pressure fluctuations on this diameter and design diameter were analysed, minor differences were observed. This position can be considered to help improving the flow of the pump turbine.

  15. Where do winds come from? A new theory on how water vapor condensation influences atmospheric pressure and dynamics

    CERN Document Server

    Makarieva, A M; Sheil, D; Nobre, A D; Li, B -L

    2010-01-01

    Phase transitions of atmospheric water play a ubiquitous role in the Earth's climate system, but their direct impact on atmospheric dynamics has escaped wide attention. Here we examine and advance a theory as to how condensation influences atmospheric pressure through the mass removal of water from the gas phase with a simultaneous account of the latent heat release. Building from the fundamental physical principles we show that condensation is associated with a decline in air pressure in the lower atmosphere. This decline occurs up to a certain height, which ranges from 3 to 4 km for surface temperatures from 10 to 30 deg C. We then estimate the horizontal pressure differences associated with water vapor condensation and find that these are comparable in magnitude with the pressure differences driving observed circulation patterns. The water vapor delivered to the atmosphere via evaporation represents a store of potential energy available to accelerate air and thus drive winds. Our estimates suggest that the...

  16. Behavior of vascular resistance undergoing various pressure insufflation and perfusion on decellularized lungs.

    Science.gov (United States)

    da Palma, Renata Kelly; Nonaka, Paula Naomi; Campillo, Noelia; Uriarte, Juan J; Urbano, Jessica Julioti; Navajas, Daniel; Farré, Ramon; Oliveira, Luis V F

    2016-05-01

    Bioengineering of functional lung tissue by using whole lung scaffolds has been proposed as a potential alternative for patients awaiting lung transplant. Previous studies have demonstrated that vascular resistance (Rv) could be altered to optimize the process of obtaining suitable lung scaffolds. Therefore, this work was aimed at determining how lung inflation (tracheal pressure) and perfusion (pulmonary arterial pressure) affect vascular resistance. This study was carried out using the lungs excised from 5 healthy male Sprague-Dawley rats. The trachea was cannulated and connected to a continuous positive airway pressure (CPAP) device to provide a tracheal pressure ranging from 0 to 15cmH2O. The pulmonary artery was cannulated and connected to a controlled perfusion system with continuous pressure (gravimetric level) ranging from 5 to 30cmH2O. Effective Rv was calculated by ratio of pulmonary artery pressure (PPA) by pulmonary artery flow (V'PA). Rv in the decellularized lungs scaffolds decreased at increasing V'PA, stabilizing at a pulmonary arterial pressure greater than 20cmH2O. On the other hand, CPAP had no influence on vascular resistance in the lung scaffolds after being subjected to pulmonary artery pressure of 5cmH2O. In conclusion, compared to positive airway pressure, arterial lung pressure markedly influences the mechanics of vascular resistance in decellularized lungs. PMID:26949099

  17. Influence of albuminuria and glomerular filtration rate on blood pressure response to antihypertensive drug therapy

    Directory of Open Access Journals (Sweden)

    John M Flack

    2008-01-01

    Full Text Available John M Flack1, Karl Duncan2, Suzanne E Ohmit3, Ruth Quah1, Xuefeng Liu1, Preeti Ramappa1, Sandra Norris1, Lowell Hedquist1, Amanda Dudley1, Samar A Nasser11Division of Translational Research and Clinical Epidemiology, Department of Internal Medicine, Wayne State University, Detroit, MI, USA; 2Department of Interventional Cardiology, Harper University Hospital, Detroit Medical Center, Detroit, MI, USA; 3School of Public Health, University of Michigan, Ann Arbor, MI, USABackground: Albuminuria and glomerular filtration rate (GFR, two factors linked to kidney and vascular function, may influence longitudinal blood pressure (BP responses to complex antihypertensive drug regimens.Methods: We reviewed the clinic records of 459 patients with hypertension in an urban, academic practice.Results: Mean patient age was 57-years, 89% of patients were African American, and 69% were women. Mean patient systolic/diastolic BP (SBP/DBP at baseline was 171/98 mmHg while taking an average of 3.3 antihypertensive medications. At baseline, 27% of patients had estimated (eGFR <60 ml/min/1.732, 28% had micro-albuminuria (30–300 mg/g and 16% had macro-albuminuria (300 mg/g. The average longitudinal BP decline over the observation period (mean 7.2 visits was 25/12 mmHg. In adjusted regression models, macro-albuminuria predicted a 10.3 mmHg lesser longitudinal SBP reduction (p < 0.001 and a 7.9 mmHg lesser longitudinal DBP reduction (p < 0.001; similarly eGFR <60 ml/min/1.732 predicted an 8.4 mmHg lesser longitudinal SBP reduction (p < 0.001 and a 4.5 lesser longitudinal DBP reduction (p < 0.001. Presence of either micro- or macro-albuminuria, or lower eGFR, also significantly delayed the time to attainment of goal BP.Conclusions: These data suggest that an attenuated decline in BP in drug-treated hypertensives, resulting in higher average BP levels over the long-term, may mediate a portion of the increased risk of cardiovascular-renal disease linked to elevated

  18. Influence of oxygen at high pressure on the induction of damage in barley seeds by gamma radiation

    International Nuclear Information System (INIS)

    The influence of oxygen pressure prior to, during, and after irradiation on the induction of radiation damage was investigated using Himalaya (C.I. 620) barley seeds. Seeds were adjusted to water contents of 2 to 14% and then irradiated with 60Co gamma rays in vacuo or under various oxygen tensions. After irradiation, the seeds were rehydrated at approximately 00C in water continuously bubbled with oxygen or nitrogen. Biological effects of the treatments were recorded as M1 seedling injury. Seeds irradiated in oxygen pressure sustained two or three times more damage than those irradiated in vacuo followed by rehydrating in oxygenated water. Greater damage occurred when seeds were (a) exposed to oxygen pressure and the pressure released before irradiation, (b) irradiated under oxygen pressure, or (c) irradiated in vacuo and then exposed to oxygen pressure than when irradiated in vacuo and rehydrated in oxygenated water. These results suggest that seeds can be saturated with oxygen before irradiation and also that the radiation-induced sites (presumably free radicals) which react with the oxygen are somewhat stable in very dry seeds. That the reaction probably occurs before the seeds are rehydrated was demonstrated by the failure to remove the effect of oxygen pressure between high oxygen pressure treatment and irradiation. The results indicate that placing the seeds under oxygen pressure may increase the rate and extent of the reactions occurring during post-radiation storage of seeds in the presence of oxygen. The increase in damage associated with aerobic rehydration is partially lost during aerobic storage and is largely pre-empted when seeds are placed under oxygen pressure. The decrease in damage associated with aerobic rehydration is accompanied by an increase in damage occurring with anaerobic rehydration, suggesting that the reaction which leads to damage was initiated before rehydration and to the same oxygen sensitive sites

  19. 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

  20. Increased airway glucose increases airway bacterial load in hyperglycaemia.

    Science.gov (United States)

    Gill, Simren K; Hui, Kailyn; Farne, Hugo; Garnett, James P; Baines, Deborah L; Moore, Luke S P; Holmes, Alison H; Filloux, Alain; Tregoning, John S

    2016-01-01

    Diabetes is associated with increased frequency of hospitalization due to bacterial lung infection. We hypothesize that increased airway glucose caused by hyperglycaemia leads to increased bacterial loads. In critical care patients, we observed that respiratory tract bacterial colonisation is significantly more likely when blood glucose is high. We engineered mutants in genes affecting glucose uptake and metabolism (oprB, gltK, gtrS and glk) in Pseudomonas aeruginosa, strain PAO1. These mutants displayed attenuated growth in minimal medium supplemented with glucose as the sole carbon source. The effect of glucose on growth in vivo was tested using streptozocin-induced, hyperglycaemic mice, which have significantly greater airway glucose. Bacterial burden in hyperglycaemic animals was greater than control animals when infected with wild type but not mutant PAO1. Metformin pre-treatment of hyperglycaemic animals reduced both airway glucose and bacterial load. These data support airway glucose as a critical determinant of increased bacterial load during diabetes. PMID:27273266

  1. Rare Upper Airway Anomalies.

    Science.gov (United States)

    Windsor, Alanna; Clemmens, Clarice; Jacobs, Ian N

    2016-01-01

    A broad spectrum of congenital upper airway anomalies can occur as a result of errors during embryologic development. In this review, we will describe the clinical presentation, diagnosis, and management strategies for a few select, rare congenital malformations of this system. The diagnostic tools used in workup of these disorders range from prenatal tests to radiological imaging, swallowing evaluations, indirect or direct laryngoscopy, and rigid bronchoscopy. While these congenital defects can occur in isolation, they are often associated with disorders of other organ systems or may present as part of a syndrome. Therefore workup and treatment planning for patients with these disorders often involves a team of multiple specialists, including paediatricians, otolaryngologists, pulmonologists, speech pathologists, gastroenterologists, and geneticists. PMID:26277452

  2. Eddy measurements on CANDU pressure tubes (I). The influence of the metallurgical states

    International Nuclear Information System (INIS)

    The experimental results, concerning the hydrogen content into the CANDU pressure tube by eddy current measurements, are described.The absorption and precipitation of hydrogen in zirconium alloys are affected by the macroscopic conditions (temperature, mechanical stresses etc.) and by the microstructural characteristics of alloy (grains structure, oxygen content etc.). The experimental study of electrical conductivity of Zr-2.5%Nb depending on the hydrogen content, include the influence of other processes, which affected the metallurgical state of samples. Consequently, the experimental study consists of the electrical conductivity measurements on the samples with the following characteristics: samples as received (CH0 = 9 ppm; CO0 = 1000 ppm), hydride samples by gas-metal reaction at thermodynamic equilibrium (CHmax = 155 ppm), oxidized samples (COmax = 1200 ppm), recrystallized samples by heating in gauge in the temperature range from 3000 deg. C to 8000 deg. C and in the time interval from 4 hours to 56.5 hours.The rectangular channel with axial orientation on the internal surface of the samples (reference defects) was processed for all the samples. The reference defects were dimensionally characterized before and after thermal treatments. No dimensional modification of the defects was observed. The influences of the metallurgical state on the defect signals are determined by electrical conductivity changes of samples. The values determined by eddy current method were compared with the electrical conductivity determined by four-probes method. The hydriding process induced decreases of the resistivity with Δρ≅8μΩ·cm. These results were obtained by both methods. For the oxidized samples, the results are the same for the eddy current and four-probes methods, but these are in contradiction with other results reported in the literature. It is possible that another effects associated with thermal treatments could induce the decrease of the electrical

  3. Nonlinear equilibrium structure of thin currents sheets: influence of electron pressure anisotropy

    Directory of Open Access Journals (Sweden)

    L. M. Zelenyi

    2004-01-01

    Full Text Available Thin current sheets represent important and puzzling sites of magnetic energy storage and subsequent fast release. Such structures are observed in planetary magnetospheres, solar atmosphere and are expected to be widespread in nature. The thin current sheet structure resembles a collapsing MHD solution with a plane singularity. Being potential sites of effective energy accumulation, these structures have received a good deal of attention during the last decade, especially after the launch of the multiprobe CLUSTER mission which is capable of resolving their 3D features. Many theoretical models of thin current sheet dynamics, including the well-known current sheet bifurcation, have been developed recently. A self-consistent 1D analytical model of thin current sheets in which the tension of the magnetic field lines is balanced by the ion inertia rather than by the plasma pressure gradients was developed earlier. The influence of the anisotropic electron population and of the corresponding electrostatic field that acts to restore quasi-neutrality of the plasma is taken into account. It is assumed that the electron motion is fluid-like in the direction perpendicular to the magnetic field and fast enough to support quasi-equilibrium Boltzmann distribution along the field lines. Electrostatic effects lead to an interesting feature of the current density profile inside the current sheet, i.e. a narrow sharp peak of electron current in the very center of the sheet due to fast curvature drift of the particles in this region. The corresponding magnetic field profile becomes much steeper near the neutral plane although the total cross-tail current is in all cases dominated by the ion contribution. The dependence of electrostatic effects on the ion to electron temperature ratio, the curvature of the magnetic field lines, and the average electron magnetic moment is also analyzed. The implications of these effects on the fine structure of thin current sheets

  4. Arterial pressure measurement: Is the envelope curve of the oscillometric method influenced by arterial stiffness?

    Energy Technology Data Exchange (ETDEWEB)

    Gelido, G [Electronic department, Universidad Tecnologica Nacional FRBA, Bs. As. (Argentina); Angiletta, S [Electronic department, Universidad Tecnologica Nacional FRBA, Bs. As. (Argentina); Pujalte, A [Electronic department, Universidad Tecnologica Nacional FRBA, Bs. As. (Argentina); Quiroga, P [Electronic department, Universidad Favaloro FICEN, Bs. As. (Argentina); Cornes, P [Electronic department, Universidad Favaloro FICEN, Bs. As. (Argentina); Craiem, D [Electronic department, Universidad Favaloro FICEN, Bs. As. (Argentina)

    2007-11-15

    Measurement of peripheral arterial pressure using the oscillometric method is commonly used by professionals as well as by patients in their homes. This non invasive automatic method is fast, efficient and the required equipment is affordable with a low cost. The measurement method consists of obtaining parameters from a calibrated decreasing curve that is modulated by heart beats witch appear when arterial pressure reaches the cuff pressure. Diastolic, mean and systolic pressures are obtained calculating particular instants from the heart beats envelope curve. In this article we analyze the envelope of this amplified curve to find out if its morphology is related to arterial stiffness in patients. We found, in 33 volunteers, that the envelope waveform width correlates to systolic pressure (r=0.4, p<0.05), to pulse pressure (r=0.6, p<0.05) and to pulse pressure normalized to systolic pressure (r=0.6, p<0.05). We believe that the morphology of the heart beats envelope curve obtained with the oscillometric method for peripheral pressure measurement depends on arterial stiffness and can be used to enhance pressure measurements.

  5. Arterial pressure measurement: Is the envelope curve of the oscillometric method influenced by arterial stiffness?

    International Nuclear Information System (INIS)

    Measurement of peripheral arterial pressure using the oscillometric method is commonly used by professionals as well as by patients in their homes. This non invasive automatic method is fast, efficient and the required equipment is affordable with a low cost. The measurement method consists of obtaining parameters from a calibrated decreasing curve that is modulated by heart beats witch appear when arterial pressure reaches the cuff pressure. Diastolic, mean and systolic pressures are obtained calculating particular instants from the heart beats envelope curve. In this article we analyze the envelope of this amplified curve to find out if its morphology is related to arterial stiffness in patients. We found, in 33 volunteers, that the envelope waveform width correlates to systolic pressure (r=0.4, p<0.05), to pulse pressure (r=0.6, p<0.05) and to pulse pressure normalized to systolic pressure (r=0.6, p<0.05). We believe that the morphology of the heart beats envelope curve obtained with the oscillometric method for peripheral pressure measurement depends on arterial stiffness and can be used to enhance pressure measurements

  6. 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.

  7. Evaluation of the upper respiratory tract in the horse during treadmill exercise - A review Part ll: Measurement of upper airway flow mechanics

    OpenAIRE

    Kästner, Sabine Beate Rita; Weishaupt, Michael A; Townsend, Hugh G.G.

    1998-01-01

    Literature pertaining to the evaluation of the upper respiratory tract of the horse during exercise was reviewed. Articles were found by searching two databases. Videoendoscopy of the upper airways during exercise is presented in part I of this review. Part II describes upper airway pressure and airflow measurements for objective assessement of the prescence of a respiratory limitation. Different measurement techniques and definitions of upper airway pressure as well as airflow measurement te...

  8. 肺泡表面活性物质联合气道正压通气治疗新生儿呼吸窘迫综合症的相关护理%The nursing care effects of pulmonary surfactant combined with continuous positive airway pressure in the treatment of NRDS

    Institute of Scientific and Technical Information of China (English)

    袁春梅

    2014-01-01

    目的:探讨肺泡表面活性物质联合气道正压通气治疗新生儿呼吸窘迫综合症的相关护理。方法选择我院100例患有新生儿呼吸窘迫综合症(NRDS)的早产儿,予患儿肺表面活性物理联合气道正压通气(NCPAP)进行治疗。在患儿治疗期间,注意药物的用法用量,病情监测,患儿的保暖,呼吸道管理等综合护理措施。结果经过治疗后36例患儿症状与体征有明显改善。患儿治疗后6h PaO2明显上升(P<0.05),PaCO2明显下降(P<0.05)。结论肺泡表面活性物质联合气道正压通气治疗新生儿呼吸窘迫综合症临床疗效显著,有效降低并发症的发病率,改善了患儿预后情况。%Objective: To explore the nursing care effect of pulmonary surfactant combined with continuous positive airway pressure in the treatment of NRDS. Methods: 100 premature infants enroled in this study were treated with pulmonary surfactant and continuous positive airway pressure. And during the treatment,be aware of the medicine use,monitoring the infants ‘condition and etc. Results: The infants’ condition were greatly improved after the combined treatment. The 6h PaO2 were increased with PaCO2 decreasing. Conclusion:Pulmonary surfactant combined with continuous positive airway pressure have a significant effect in the treatment of NRDS.

  9. 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...... 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...

  10. The Virtual Pediatric Airways Workbench.

    Science.gov (United States)

    Quammen, Cory W; Taylor Ii, Russell M; Krajcevski, Pavel; Mitran, Sorin; Enquobahrie, Andinet; Superfine, Richard; Davis, Brad; Davis, Stephanie; Zdanski, Carlton

    2016-01-01

    The Virtual Pediatric Airways Workbench (VPAW) is a patient-centered surgical planning software system targeted to pediatric patients with airway obstruction. VPAW provides an intuitive surgical planning interface for clinicians and supports quantitative analysis regarding prospective surgeries to aid clinicians deciding on potential surgical intervention. VPAW enables a full surgical planning pipeline, including importing DICOM images, segmenting the airway, interactive 3D editing of airway geometries to express potential surgical treatment planning options, and creating input files for offline geometric analysis and computational fluid dynamics simulations for evaluation of surgical outcomes. In this paper, we describe the VPAW system and its use in one case study with a clinician to successfully describe an intended surgery outcome. PMID:27046595

  11. Simultaneous ultrasonic velocities, porosity and pressure measurements at upper to lower crustal pressures using piston-cylinder apparatus: Influence of microcracks on the elastic properties of crustal rocks

    Science.gov (United States)

    Saito, S.; Ishikawa, M.; Arima, M.; Tatsumi, Y.

    2009-12-01

    Earthquakes must be preceded by the formation and growth of microcracks in rocks. In order to estimate the distribution of microcracks in earthquake source areas, it is important to assess the influence of microcracks on the elastic properties of rocks. Multiple techniques measuring ultrasonic compressional (Vp) and shear wave velocities (Vs), elastic moduli using ultrasonic interferometry, sample volume using inversion of the determined elastic moduli, the cell pressure using ultrasonic interferometry were adapted simultaneously to a piston-cylinder type high-pressure apparatus, allowing measurements of Vp and Vs at upper to lower crustal pressures (0.2-1.0GPa). Combined analysis of the ultrasonic velocities and volume data enables us to determine influence of microcracks on Vp, Vs, Vp/Vs and Poisson’s ratio for crustal rocks. Furthermore, cell pressure can be directly calculated using the in situ monitoring of elastic data of buffer rod, providing a means to calibrate the cell pressure in a piston-cylinder apparatus at low pressures. In this study, we present the experimental procedures and results on a gabbro sample to 1.0GPa at room temperature. Using the data obtained, we discuss the influence of microcracks on the Vp, Vs, Vp/Vs and Poisson’s ratio. We used a gabbro sample collected from Wadi Bani Umar area in the Oman Ophiolite for the experiment. The sample is homogeneous and isotropic rock consisting of plagioclase (58vol%), clinopyroxene (23vol%), orthopyroxene (8vol%), olivine (8vol%), serpentine (2vol%) and magnetite (1vol%). We measured elastic velocities at 0.05GPa intervals from 0.2GPa to 1.0GPa. The determined Vp, Vs, Vp/Vs, and Poisson’s ratio increase rapidly from 0.2GPa to 0.4GPa, and gradually increase from 0.45GPa to 1.0GPa. This result is attributed to the closure of open microcracks at high pressure (>0.45GPa). At 1.0GPa, the Vp, Vs, Vp/Vs, and Poisson’s ratio were 7.13km/s, 3.85km/s, 1.85, and 0.294, respectively. Extrapolation of

  12. WWER-1000 core loading characteristic influence on irradiation conditions of surveillance specimens and reactor pressure vessel

    International Nuclear Information System (INIS)

    Irradiation conditions of WWER-1000 surveillance specimens and reactor pressure vessel are comparative analyzed for various core loadings. It is proved that the fluences onto specimens don't correlate with ones onto pressure vessel. It is shown that the reconstruction technique using to surveillance specimens of the standard program implemented at the most of the power units with WWER-1000 allows obtaining reliable information on the reactor pressure vessel metal states

  13. Airway Inflammation and Structural Changes in Airway Hyper-Responsiveness and Asthma: An Overview

    OpenAIRE

    Louis-Philippe Boulet; Jamila Chakir; Jean Dubé; Catherine Laprise; Michel Boutet; Michel Laviolette

    1998-01-01

    Asthma treatment has moved from bronchodilator therapy to an emphasis on anti-inflammatory therapy. Airway inflammation is believed to induce airway hyper-responsiveness (AHR) through the release of mediators that increase the airway response to agonists. However, the exact contribution of airway inflammation in the physiology of airway hyper-responsiveness remains undefined. Structural modifications in airways resulting from inflammation may contribute to the development and persistence of A...

  14. Pressure Regulators as Valves for Saving Compressed Air and their Influence on System Dynamics

    Directory of Open Access Journals (Sweden)

    Dvořák Lukáš

    2015-01-01

    Full Text Available Pressure regulators in the field of pneumatic mechanisms can be used as valves for saving compressed air. For example it can be used to reduce the pressure when the piston rod is retracting unloaded and thus it is possible to save some energy. However the problem is that saving valve can significantly affect the dynamics of the pneumatic system. The lower pressure in the piston rod chamber causes extension of time for retraction of the piston rod. This article compare the air consumption experimentally determined and calculated, measured curves of pressure in cylinder chambers and piston speed when saving valve is set up differently.

  15. Pressure Regulators as Valves for Saving Compressed Air and their Influence on System Dynamics

    Science.gov (United States)

    Dvořák, Lukáš; Fojtášek, Kamil

    2015-05-01

    Pressure regulators in the field of pneumatic mechanisms can be used as valves for saving compressed air. For example it can be used to reduce the pressure when the piston rod is retracting unloaded and thus it is possible to save some energy. However the problem is that saving valve can significantly affect the dynamics of the pneumatic system. The lower pressure in the piston rod chamber causes extension of time for retraction of the piston rod. This article compare the air consumption experimentally determined and calculated, measured curves of pressure in cylinder chambers and piston speed when saving valve is set up differently.

  16. Influence of the homogenization pressure on the ice cream mix quality

    Directory of Open Access Journals (Sweden)

    Iva Murgić

    2008-08-01

    Full Text Available In this paper the suitability of different homogenization pressures on appearance and quality of ice cream mix was determined. The ice cream mix were taken from ageing tank, and depending on the source of fat in ice cream mix (butter, vegetable fat or cream they were homogenized under different pressures. Afterwards, by microscope with scalar, fat globule size was determined. The homogenization pressures reduce the fat globule size to 1-2 μm without clumping and these pressures have been characterized as adequate pressures for specific type of fat and specific portion of fat in the ice cream mixture. The higher the fat in the mixture, the lower the pressure should be. The optimal pressure for ice cream mixture containing 2% vegetable fat was 200 bars, for 6% 190-200 bars, and for 8% 170 bars. The optimal pressure for ice cream mixture that contained 8% butter was 190-200 bars, for 10% 150, and for 12% 135 bars. For ice cream mixture containing 8% of cream, optimal pressure was 200 bars, 10% cream was 190, 12% cream was 125 bars and 14% cream was 90 bars.

  17. 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.

  18. TRP channels and temperature in airway disease—clinical significance

    Science.gov (United States)

    Millqvist, Eva

    2015-01-01

    Temperatures above and below what is generally regarded as “comfortable” for the human being have long been known to induce various airway symptoms, especially in combination with exercise in cold climate with temperatures below 0°C, which is naturally since exercise is followed by enhanced ventilation and thus greater amounts of inhaled cold air. The aim was to highlight the knowledge we have today on symptoms from the airways (here also including the eyes) arisen from various temperatures; the mechanisms, the pathophysiology and their clinical significance. The most common eye and airway conditions related to temperature changes are dry eye disease, rhinitis, laryngeal dysfunction, asthma, chronic obstructive pulmonary disease and chronic cough. Transient receptor potential (TRP) ion channels are probably involved in all temperature induced airway symptoms but via different pathways, which are now beginning to be mapped out. In asthma, the most persuasive hypothesis today is that cold-induced asthmatic bronchoconstriction is induced by dehydration of the airway mucosa, from which it follows that provocations with osmotic stimuli like hypertonic saline and mannitol can be used as a surrogate for exercise provocation as well as dry air inhalation. In chronic unexplained cough there seems to be a direct influence of cold air on the TRP ion channels followed by coughing and increased cough sensitivity to inhaled capsaicin. Revelations in the last decades of the ability of several airway TRP ion channels to sense and react to ambient air temperature have opened new windows for the understanding of the pathogenesis in a diversity of airway reactions appearing in many common respiratory diseases. PMID:27227021

  19. The influence of endotracheal tube cuff pressures to PEEP values in mechanical ventilated patients%机械通气患者套囊压力的监测

    Institute of Scientific and Technical Information of China (English)

    仇成秀; 刘志梅; 钟琼

    2011-01-01

    目的 讨论机械通气患者气管插管导管、气管切开套管的套囊压力和注气量是否合适,提供正确给套囊注气的科学依据.方法 对35例气管插管、气管切开进行机械通气患者的气管套管套囊压力和注气量的实际值和理想值进行准确测量.结果 65%的患者气管套管套囊实际压力和注气量过高,大于理想值.其中套囊实际注气量大于理想注气量2~4ml,套囊压力超过理想压力2~26 cm H2O.结论 临床上大部分气管套管套囊压力和注气量偏高,因此,应对人工气道患者采用专用套囊测压仪指导套囊注气量及控制囊内压,最大限度地避免气道黏膜的损伤.%Objective In cases of tracheal intubation of patients with a mechanical ventilation tube,measure trachootomy tube cuff pressure and the injection of gas whether it was providing appropriate pressure under the conditions of the use of gas injection basis.Methods In 35 cases of tracheal intubation,measure the endotracheal tube cuff pressure of mechanical ventilation patients with tracheotomy and note the actual value and the ideal gas value of accurate measurement.Results About 65% of patients with tracheal tube cuff pressure and the actual injection gas were too high,greater than the ideal value.One cuff was greater than the actual injection gas ideal gas injection rate 2 ~4 ml,the pressure cuff pressure above the ideal of 2 ~ 26 cm H2 O.Conclusion Most of the clinical tracheal tube cuff pressure indicates too high gas injection,so doctors should use a dedicated artificial airway cuff pressure measuring instrument to guide and control cuff intracystic injection gas pressure in order to avoid possible damage of airway mucosa.

  20. Surfactant and allergic airway inflammation.

    Science.gov (United States)

    Winkler, Carla; Hohlfeld, Jens M

    2013-01-01

    Pulmonary surfactant is a complex mixture of unique proteins and lipids that covers the airway lumen. Surfactant prevents alveolar collapse and maintains airway patency by reducing surface tension at the air-liquid interface. Furthermore, it provides a defence against antigen uptake by binding foreign particles and enhancing cellular immune responses. Allergic asthma is associated with chronic airway inflammation and presents with episodes of airway narrowing. The pulmonary inflammation and bronchoconstriction can be triggered by exposure to allergens or pathogens present in the inhaled air. Pulmonary surfactant has the potential to interact with various immune cells which orchestrate allergen- or pathogen-driven episodes of airway inflammation. The complex nature of surfactant allows multiple sites of interaction, but also makes it susceptible to external alterations, which potentially impair its function. This duality of modulating airway physiology and immunology during inflammatory conditions, while at the same time being prone to alterations accompanied by restricted function, has stimulated numerous studies in recent decades, which are reviewed in this article. PMID:23896983

  1. Influence of buoyancy forces on the flow of gases through packed beds at elevated pressures

    NARCIS (Netherlands)

    Benneker, A.H.; Kronberg, A.E.; Westerterp, K.R.

    1998-01-01

    The flow of gases through packed-bed columns at elevated pressures was investigated by displacement experiments with a stepwise change in the tracer concentration. The experiments with different tracers, flow rates, pressures, particle sizes, tube diameters, and flow directions were used to illustra

  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 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...... 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. 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.......4±4.2 mmHg when standing up (P<0.05). Concordant changes in MAP maintained CPP at 77±7 mmHg regardless of body position (P=0.95). During head-down tilt, the increase in ICP corresponded to a hydrostatic pressure gradient with reference just below the heart, likely reflecting the venous hydrostatic...... veins may protect the brain from being exposed to a large negative pressure when upright. Despite positional changes in ICP, MAP keeps CPP tightly regulated....

  4. 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.

  5. Influence of hydrostatic pressure on superconducting properties of niobium thin film

    International Nuclear Information System (INIS)

    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 TC for thin film and for bulk sample

  6. Border control! Capillary pressure / saturation relationships in a diphasic flow in a random medium: Influence of the boundary conditions

    Science.gov (United States)

    Fiorentino, Eve-Agnès; Toussaint, Renaud; Moura, Marcel; Jankov, Mihailo; Schäfer, Gerhard; Jørgen Måløy, Knut

    2013-04-01

    Solving problems involving biphasic flows in porous media, at a scale larger than the pore one, normally requires the use of relationships between pressure and saturation. These allow the closure of generalized Darcy flow models for two phases, commonly used in hydrology or large scale problems of diphasic flow in porous media. There are mathematical models which approximate experimental records with curve-fitting equations. The two most common models are the Brooks-Corey and van Genüchten ones, they are used to complete a system of generalized Darcy equations. The purpose of the current study is the influence of the boundary conditions on the relationship between pressure and saturation. We perform numerical simulations of drainage experiments. Water is the wetting fluid and air is the non wetting fluid. The results highlight the fact that a filter which allows only water to flow at the exit face of the system modifies both the shape of the curve and the value of the residual saturation. The pressure of the models that are commonly used does not match with the pressure of real flows since there is no filter to cross, to flow from an elementary volume to another. Experiments performed in transparent Hele-Shaw cells exhibit the same features, showing the influence of the semi permeable boundary conditions on the pressure-saturation measures obtained. This effect corresponding to the formation of localized plugging clusters at the boundaries, is obtained in slow flow conditions, and is independent of any dynamic fingering, also known to affect such relations (1,2,3). Modeling flows in open media thus would require to use the central part of the curves pressure saturation where the effect of the boundaries is the least important, or to modify properly these relationships to extract the behavior unaffected by boundaries. References: (1) Two-phase flow: structure, upscaling, and consequences for macroscopic transport properties Renaud Toussaint ; Knut Jørgen M

  7. Influence of xanthan gum on the structural characteristics of myofibrillar proteins treated by high pressure.

    Science.gov (United States)

    Villamonte, Gina; Jury, Vanessa; Jung, Stéphanie; de Lamballerie, Marie

    2015-03-01

    The effects of xanthan gum on the structural modifications of myofibrillar proteins (0.3 M NaCl, pH 6) induced by high pressure (200, 400, and 600 MPa, 6 min) were investigated. The changes in the secondary and tertiary structures of myofibrillar proteins were analyzed by circular dichroism. The protein denaturation was also evaluated by differential scanning calorimetry. Likewise, the protein surface hydrophobicity and the solubility of myofibrillar proteins were measured. High pressure (600 MPa) induced the loss of α-helix structures and an increase of β-sheet structures. However, the presence of xanthan gum hindered the former mechanism of protein denaturation by high pressure. In fact, changes in the secondary (600 MPa) and the tertiary structure fingerprint of high-pressure-treated myofibrillar proteins (400 to 600 MPa) were observed in the presence of xanthan gum. These modifications were confirmed by the thermal analysis, the thermal transitions of high-pressure (400 to 600 MPa)-treated myofibrillar proteins were modified in systems containing xanthan gum. As consequence, the high-pressure-treated myofibrillar proteins with xanthan gum showed increased solubility from 400 MPa, in contrast to high-pressure treatment (600 MPa) without xanthan gum. Moreover, the surface hydrophobicity of high-pressure-treated myofibrillar proteins was enhanced in the presence of xanthan gum. These effects could be due to the unfolding of myofibrillar proteins at high-pressure levels, which exposed sites that most likely interacted with the anionic polysaccharide. This study suggests that the role of food additives could be considered for the development of meat products produced by high-pressure processing. PMID:25656483

  8. 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.

  9. Genetic and environmental influences on blood pressure and physical activity: a study of nuclear families from Muzambinho, Brazil

    OpenAIRE

    Forjaz, C.L.M.; Bartholomeu, T.; J.A.S. Rezende; J. A. de Oliveira; Basso, L.; Tani, G.; A. Prista; Maia, J.A.R.

    2012-01-01

    Blood pressure (BP) and physical activity (PA) levels are inversely associated. Since genetic factors account for the observed variation in each of these traits, it is possible that part of their association may be related to common genetic and/or environmental influences. Thus, this study was designed to estimate the genetic and environmental correlations of BP and PA phenotypes in nuclear families from Muzambinho, Brazil. Families including 236 offspring (6 to 24 years) and their 82 fathers...

  10. Continuous estimates of dynamic cerebral autoregulation: influence of non-invasive arterial blood pressure measurements

    International Nuclear Information System (INIS)

    Temporal variability of parameters which describe dynamic cerebral autoregulation (CA), usually quantified by the short-term relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), could result from continuous adjustments in physiological regulatory mechanisms or could be the result of artefacts in methods of measurement, such as the use of non-invasive measurements of BP in the finger. In 27 subjects (61 ± 11 years old) undergoing coronary artery angioplasty, BP was continuously recorded at rest with the Finapres device and in the ascending aorta (Millar catheter, BPAO), together with bilateral transcranial Doppler ultrasound in the middle cerebral artery, surface ECG and transcutaneous CO2. Dynamic CA was expressed by the autoregulation index (ARI), ranging from 0 (absence of CA) to 9 (best CA). Time-varying, continuous estimates of ARI (ARI(t)) were obtained with an autoregressive moving-average (ARMA) model applied to a 60 s sliding data window. No significant differences were observed in the accuracy and precision of ARI(t) between estimates derived from the Finapres and BPAO. Highly significant correlations were obtained between ARI(t) estimates from the right and left middle cerebral artery (MCA) (Finapres r = 0.60 ± 0.20; BPAO r = 0.56 ± 0.22) and also between the ARI(t) estimates from the Finapres and BPAO (right MCA r = 0.70 ± 0.22; left MCA r = 0.74 ± 0.22). Surrogate data showed that ARI(t) was highly sensitive to the presence of noise in the CBFV signal, with both the bias and dispersion of estimates increasing for lower values of ARI(t). This effect could explain the sudden drops of ARI(t) to zero as reported previously. Simulated sudden changes in ARI(t) can be detected by the Finapres, but the bias and variability of estimates also increase for lower values of ARI. In summary, the Finapres does not distort time-varying estimates of dynamic CA obtained with a sliding window combined with an ARMA model, but

  11. Adaptação do Bird Mark 7 para oferta de pressão positiva contínua nas vias aéreas em ventilação não-invasiva: estudo em modelo mecânico Adapting the Bird Mark 7 to deliver noninvasive continuous positive airway pressure: a bench study

    OpenAIRE

    Beatriz Mayumi Kikuti; Karen Utsunomia; Renata Potonyacz Colaneri; Carlos Roberto Ribeiro Carvalho; Pedro Caruso

    2008-01-01

    OBJETIVO: Testar a eficiência da adaptação do ventilador Bird Mark 7 para oferecer pressão positiva contínua nas vias aéreas, conhecida como continuous positive airway pressure (CPAP) em inglês, em ventilação não-invasiva. MÉTODOS: Estudo experimental utilizando um modelo mecânico do sistema respiratório. O Bird Mark 7 foi alimentado com 400 e 500 kPa e foi testado em CPAP de 5, 10 e 15 cmH2O. Para avaliar a eficiência da adaptação foram analisados os seguintes variáveis: diferença entre a CP...

  12. Influence of different substrates on the performance of a two-stage high pressure anaerobic digestion system.

    Science.gov (United States)

    Lemmer, A; Chen, Y; Lindner, J; Wonneberger, A M; Zielonka, S; Oechsner, H; Jungbluth, T

    2015-02-01

    The two-stage autogenerative high-pressure digestion technique is a novel and promising approach for the production of gaseous fuels or upgraded biogas. This new technique is described in the patent DE 10 2011 015415 A1 and integrates biogas production, its upgrading and pressure boosting in one process. Anaerobic digestion under elevated pressure conditions leads to decreasing pH-values in the digestate due to the augmented formation of carboxylic acid. Model calculations carried out to evaluate the two-stage design showed that the pH-value in the pressurized anaerobic filter has a major influence on the methane content of the biogas produced. Within this study, the influence of the nitrogen content as one of the most important buffering substances on the performance of the system has been tested. The results show that higher NH4 contents lead to higher pH-values in the digester and as a consequence to higher methane contents. PMID:25451774

  13. Blood pressure in patients with primary aldosteronism is influenced by bradykinin B(2) receptor and alpha-adducin gene polymorphisms.

    Science.gov (United States)

    Mulatero, Paolo; Williams, Tracy A; Milan, Alberto; Paglieri, Cristina; Rabbia, Franco; Fallo, Francesco; Veglio, Franco

    2002-07-01

    Primary aldosteronism (PA) is the most common cause of endocrine hypertension. PA is most frequently presented as moderate to severe hypertension, but the clinical and biochemical features vary widely. The aim of our study was to identify genetic variants that influence the phenotype of patients with PA. We hypothesized that genetic variants potentially affecting aldosterone production (aldosterone synthase, CYP11B2), renal proximal tubule reabsorption (alpha-adducin), or the mechanisms of counterbalance leading to vasodilatation and sodium excretion (bradykinin B(2)-receptor, B(2)R) could influence the clinical and biochemical characteristics of patients with PA. We studied three polymorphisms of these genes (C-344T of CYP11B2, G460W of alpha-adducin, and C-58T of B(2)R) in 167 primary aldosteronism patients (56 with aldosterone-producing adenoma and 111 with idiopathic hyperaldosteronism). B(2)R and alpha-adducin genotypes were strong independent predictors of both systolic and diastolic blood pressure levels; plasma renin activity and aldosterone also play a marginal role on BP levels. Body mass index, age, sex, and CYP11B2 genotype displayed no significant effect on the clinical parameters of our population. In particular, alpha-adducin and B(2)R polymorphisms accounted for 13.2% and 11.0% of the systolic and diastolic blood pressure variance, respectively. These data suggest that genetic variants of alpha-adducin and the bradykinin B(2)-R influence the blood pressure levels in patients with primary aldosteronism. PMID:12107246

  14. 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).

  15. Influence of filling on left ventricular diastolic pressure-volume curve during pacing ischemia in dogs.

    Science.gov (United States)

    Shintani, H; Glantz, S A

    1994-04-01

    The reversible upward shift of the diastolic pressure-volume curve that occurs during pacing-induced ischemia has not been fully explained by increases in passive chamber stiffness or reductions in relaxation rate. We measured the fully relaxed pressure-volume relation defined by both filling and nonfilling beats and the isovolumic relaxation time constant in nonfilling beats before and during demand ischemia using our in situ left ventricular volume clamping technique in 10 dogs. Pacing-induced ischemia shifted the diastolic pressure-volume curves in filling beats upward compared with the end-diastolic pressure-volume relation of the normally perfused heart. In contrast, the end-diastolic points for nonfilling beats during pacing-induced ischemia fell on the fully relaxed pressure-volume relation defined by the normally perfused heart. Left ventricular filling per se was necessary for the upward shift of the diastolic pressure-volume curve observed during pacing-induced ischemia. We speculate that active force developed during diastole induced by stretch activation or, perhaps, length-dependent changes in calcium sensitivity of the myofilaments in the ischemic myocardium due to stretch of the myocardium during rapid diastolic filling may contribute to the upward shift of the diastolic pressure-volume curve observed during pacing-induced ischemia. PMID:8184915

  16. A model of surfactant-induced surface tension effects on the parenchymal tethering of pulmonary airways.

    Science.gov (United States)

    Fujioka, Hideki; Halpern, David; Gaver, Donald P

    2013-01-18

    We developed a computational model of lung parenchyma, which is comprised of individual alveolar chamber models. Each alveolus is modeled by a truncated octahedron. Considering the force balance between the elastin and collagen fibers laying on the alveolar membrane and the pressures acting on the membrane, we computed the deformations of the parenchyma with a finite element method. We focused on the effect of surfactant on the force of parenchymal tethering an airway. As the lung inflates, the parenchyma becomes stiffer and the tethering force becomes stronger. As the alveolar surfactant concentration is reduced, the lung volume at a fixed alveolar pressure decreases, and thus, the tethering force becomes weaker. The distortion of parenchyma caused by the deformation of an airway extends widely around the airway. The displacement of parenchyma decays with distance from the airway wall, but deviates from the prediction based on a theory for a continuum material. Using results obtained from the present lung parenchyma model, we also developed a simple 1-dimensional model for parenchyma tethering force on an airway, which could be utilized for the analysis of liquid/gas transports in an axis-symmetric elastic airway. The effective shear modulus was calculated from the pressure-volume relation of parenchyma. By manipulating the pressure-volume curve, this simple model may be used to predict the parenchyma tethering force in diseased lungs. PMID:23235110

  17. A Microfluidic Model of Biomimetically Breathing Pulmonary Acinar Airways.

    Science.gov (United States)

    Fishler, Rami; Sznitman, Josué

    2016-01-01

    Quantifying respiratory flow characteristics in the pulmonary acinar depths and how they influence inhaled aerosol transport is critical towards optimizing drug inhalation techniques as well as predicting deposition patterns of potentially toxic airborne particles in the pulmonary alveoli. Here, soft-lithography techniques are used to fabricate complex acinar-like airway structures at the truthful anatomical length-scales that reproduce physiological acinar flow phenomena in an optically accessible system. The microfluidic device features 5 generations of bifurcating alveolated ducts with periodically expanding and contracting walls. Wall actuation is achieved by altering the pressure inside water-filled chambers surrounding the thin PDMS acinar channel walls both from the sides and the top of the device. In contrast to common multilayer microfluidic devices, where the stacking of several PDMS molds is required, a simple method is presented to fabricate the top chamber by embedding the barrel section of a syringe into the PDMS mold. This novel microfluidic setup delivers physiological breathing motions which in turn give rise to characteristic acinar air-flows. In the current study, micro particle image velocimetry (µPIV) with liquid suspended particles was used to quantify such air flows based on hydrodynamic similarity matching. The good agreement between µPIV results and expected acinar flow phenomena suggest that the microfluidic platform may serve in the near future as an attractive in vitro tool to investigate directly airborne representative particle transport and deposition in the acinar regions of the lungs. PMID:27214269

  18. Pressure Regulators as Valves for Saving Compressed Air and their Influence on System Dynamics

    OpenAIRE

    Dvořák Lukáš; Fojtášek Kamil

    2015-01-01

    Pressure regulators in the field of pneumatic mechanisms can be used as valves for saving compressed air. For example it can be used to reduce the pressure when the piston rod is retracting unloaded and thus it is possible to save some energy. However the problem is that saving valve can significantly affect the dynamics of the pneumatic system. The lower pressure in the piston rod chamber causes extension of time for retraction of the piston rod. This article compare the air consumption expe...

  19. 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).

  20. Role of Small Airways in Asthma.

    Science.gov (United States)

    Finkas, Lindsay K; Martin, Richard

    2016-08-01

    Asthma is an inflammatory condition of both the small and large airways. Recently the small airways have gained attention as studies have shown significant inflammation in the small airways in all severities of asthma. This inflammation has correlated with peripheral airway resistance and as a result, noninvasive methods to reliably measure small airways have been pursued. In addition, recent changes in asthma inhalers have led to alterations in drug formulations and the development of extrafine particle inhalers that improve delivery to the distal airways. PMID:27401620