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Sample records for airway pressure map

  1. Airway obstruction with cricoid pressure.

    PubMed

    Hartsilver, E L; Vanner, R G

    2000-03-01

    Cricoid pressure may cause airway obstruction. We investigated whether this is related to the force applied and to the technique of application. We recorded expired tidal volumes and inflation pressures during ventilation via a face-mask and oral airway in 52 female patients who were anaesthetised and about to undergo elective surgery. An inspired tidal volume of 900 ml was delivered using a ventilator. Ventilation was assessed under five different conditions: no cricoid pressure, backwards cricoid pressure applied with a force of 30 N, cricoid pressure applied in an upward and backward direction with a force of 30 N, backwards cricoid pressure with a force of 44 N and through a tracheal tube. An expired tidal volume of < 200 ml was taken to indicate airway obstruction. Airway obstruction did not occur without cricoid pressure, but did occur in one patient (2%) with cricoid pressure at 30 N, in 29 patients (56%) with 30 N applied in an upward and backward direction and in 18 (35%) patients with cricoid pressure at 44 N. Cricoid pressure applied with a force of 44 N can cause airway obstruction but if cricoid pressure is applied with a force of 30 N, airway obstruction occurs less frequently (p = 0.0001) unless the force is applied in an upward and backward direction. PMID:10671836

  2. 21 CFR 868.2600 - Airway pressure monitor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) 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...

  3. 21 CFR 868.2600 - Airway pressure monitor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) 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...

  4. 21 CFR 868.2600 - Airway pressure monitor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) 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...

  5. 21 CFR 868.2600 - Airway pressure monitor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Airway pressure monitor. 868.2600 Section 868.2600...) 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...

  6. 21 CFR 868.1780 - Inspiratory airway pressure meter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Inspiratory airway pressure meter. 868.1780... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1780 Inspiratory airway pressure meter. (a) Identification. An inspiratory airway pressure meter is a device used to measure the...

  7. 21 CFR 868.1780 - Inspiratory airway pressure meter.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Inspiratory airway pressure meter. 868.1780... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1780 Inspiratory airway pressure meter. (a) Identification. An inspiratory airway pressure meter is a device used to measure the...

  8. 21 CFR 868.1780 - Inspiratory airway pressure meter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Inspiratory airway pressure meter. 868.1780... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1780 Inspiratory airway pressure meter. (a) Identification. An inspiratory airway pressure meter is a device used to measure the...

  9. 21 CFR 868.1780 - Inspiratory airway pressure meter.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Inspiratory airway pressure meter. 868.1780... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1780 Inspiratory airway pressure meter. (a) Identification. An inspiratory airway pressure meter is a device used to measure the...

  10. 21 CFR 868.2600 - Airway pressure monitor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Airway pressure monitor. 868.2600 Section 868.2600 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Monitoring Devices § 868.2600 Airway pressure monitor....

  11. 21 CFR 868.1780 - Inspiratory airway pressure meter.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Inspiratory airway pressure meter. 868.1780 Section 868.1780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... meter. (a) Identification. An inspiratory airway pressure meter is a device used to measure the...

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

    PubMed

    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

  13. Influence of lung volume dependence of upper airway resistance during continuous negative airway pressure.

    PubMed

    Sériès, F; Marc, I

    1994-08-01

    To quantify the contribution of lung volume dependence of upper airway (UA) on continuous negative airway pressure (CNAP)-induced increase in upper airway resistance, we compared the changes in supralaryngeal resistance during an isolated decrease in lung volume and during CNAP in eight normal awake subjects. Inspiratory supralaryngeal resistance was measured at isoflow during four trials, during two CNAP trials where the pressure in a nasal mask was progressively decreased in 3- to 5-cmH2O steps and during two continuous positive extrathoracic pressure (CPEP) trials where the pressure around the chest (in an iron lung) was increased in similar steps. The CNAP and CPEP trials were done in random order. During the CPEP trial, the neck was covered by a rigid collar to prevent compression by the cervical seal of the iron lung. In each subject, resistance progressively increased during the experiments. The increase was linearily correlated with the pressure increase in the iron lung and with the square of the mask pressure during CNAP. There was a highly significant correlation between the rate of rise in resistance between CNAP and CPEP: the steeper the increase in resistance with decreasing lung volume, the steeper the increase in resistance with decreasing airway pressure. Lung volume dependence in UA resistance can account for 61% of the CNAP-induced increase in resistance. We conclude that in normal awake subjects the changes in supralaryngeal resistance induced by CNAP can partly be explained by the lung volume dependence of this resistance. PMID:8002537

  14. Use of continuous positive airway pressure reduces airway reactivity in adults with asthma

    PubMed Central

    Busk, Michael; Busk, Nancy; Puntenney, Paula; Hutchins, Janet; Yu, Zhangsheng; Gunst, Susan J.; Tepper, Robert S.

    2015-01-01

    Asthma is characterised by airway hyperreactivity, which is primarily treated with β-adrenergic bronchodilators and anti-inflammatory agents. However, mechanical strain during breathing is an important modulator of airway responsiveness and we have previously demonstrated in animal models that continuous positive airway pressure (CPAP) resulted in lower in vivo airway reactivity. We now evaluated whether using nocturnal CPAP decreased airway reactivity in clinically-stable adults with asthma. Adults with stable asthma and normal spirometry used nocturnal CPAP (8–10 cmH2O) or sham treatment (0–2 cmH2O) for 7 days. Spirometry and bronchial challenges were obtained before and after treatment. The primary outcome was the provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 s (PC20). The CPAP group (n=16) had a significant decrease in airway reactivity (change in (Δ)logPC20 0.406, p<0.0017) while the sham group (n=9) had no significant change in airway reactivity (ΔlogPC20 0.003, p=0.9850). There was a significant difference in the change in airway reactivity for the CPAP versus the sham group (ΔlogPC20 0.41, p<0.043). Our findings indicate that chronic mechanical strain of the lungs produced using nocturnal CPAP for 7 days reduced airway reactivity in clinically stable asthmatics. Future studies of longer duration are required to determine whether CPAP can also decrease asthma symptoms and/or medication usage. PMID:22835615

  15. Detection of Upper Airway Status and Respiratory Events by a Current Generation Positive Airway Pressure Device

    PubMed Central

    Li, Qing Yun; Berry, Richard B.; Goetting, Mark G.; Staley, Bethany; Soto-Calderon, Haideliza; Tsai, Sheila C.; Jasko, Jeffrey G.; Pack, Allan I.; Kuna, Samuel T.

    2015-01-01

    Study Objectives: To compare a positive airway pressure (PAP) device's detection of respiratory events and airway status during device-detected apneas with events scored on simultaneous polysomnography (PSG). Design: Prospective PSGs of patients with sleep apnea using a new-generation PAP device. Settings: Four clinical and academic sleep centers. Patients: Forty-five patients with obstructive sleep apnea (OSA) and complex sleep apnea (Comp SA) performed a PSG on PAP levels adjusted to induce respiratory events. Interventions: None. Measurements and Results: PAP device data identifying the type of respiratory event and whether the airway during a device-detected apnea was open or obstructed were compared to time-synced, manually scored respiratory events on simultaneous PSG recording. Intraclass correlation coefficients between device-detected and PSG scored events were 0.854 for apnea-hypopnea index (AHI), 0.783 for apnea index, 0.252 for hypopnea index, and 0.098 for respiratory event-related arousals index. At a device AHI (AHIFlow) of 10 events/h, area under the receiver operating characteristic curve was 0.98, with sensitivity 0.92 and specificity 0.84. AHIFlow tended to overestimate AHI on PSG at values less than 10 events/h. The device detected that the airway was obstructed in 87.4% of manually scored obstructive apneas. Of the device-detected apneas with clear airway, a minority (15.8%) were manually scored as obstructive apneas. Conclusions: A device-detected apnea-hypopnea index (AHIFlow) < 10 events/h on a positive airway pressure device is strong evidence of good treatment efficacy. Device-detected airway status agrees closely with the presumed airway status during polysomnography scored events, but should not be equated with a specific type of respiratory event. Citation: Li QY, Berry RB, Goetting MG, Staley B, Soto-Calderon H, Tsai SC, Jasko JG, Pack AI, Kuna ST. Detection of upper airway status and respiratory events by a current generation positive

  16. Duration of continuous positive airway pressure in premature infants.

    PubMed

    Bamat, Nicolas; Jensen, Erik A; Kirpalani, Haresh

    2016-06-01

    Continuous positive airway pressure (CPAP) has been used for respiratory support in premature infants for more than 40 years and is now a cornerstone of modern neonatal care. Clinical research on CPAP has primarily focused on understanding which devices and pressure sources best implement this therapy. In contrast, less research has examined the optimal duration over which CPAP is administered. We review this aspect of CPAP therapy. PMID:26948885

  17. Airway dynamics, oesophageal pressure and cough.

    PubMed

    Lavietes, M H; Smeltzer, S C; Cook, S D; Modak, R M; Smaldone, G C

    1998-01-01

    This study hypothesizes that: peak supramaximal airflow during cough reflects expiratory muscle effort, and that expiratory muscle function during cough might be assessed from the airflow signal alone. We monitored airflow and oesophageal pressure (Poes) in normal subjects during cough generated under two conditions: 1) voluntarily from functional residual capacity (FRC); and 2) involuntarily after inhalation of citric acid (CA). Maximal expiratory cough flow was quantified as the quotient of maximal flow during a given cough divided by maximal flow at the matched volume of thoracic gas (Vtg) as identified on the maximal expiratory flow-volume curve. We found: flow ratios correlated poorly with Poes; the variance of flow ratios associated with a series of voluntary coughs was poorly explained by Poes. During CA inhalation, when the Vtg compressed during cough could not be controlled, correlation of Poes with flow ratio remained poor. We conclude that to study the motor limb of the cough reflex, measurements of both airflow and oesophageal pressure are required. PMID:9543286

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

    PubMed Central

    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 infants due to start CPAP in our noninvasive ventilation unit were retrospectively analysed. CPAP set on clinical noninvasive parameters (clinical CPAP) was compared to CPAP set on the normalization or the maximal reduction of the oesophageal pressure (Poes) and transdiaphragmatic pressure (Pdi) swings (physiological CPAP). Expiratory gastric pressure (Pgas) swing was measured. Results The data of 12 infants (mean age 10 ± 8 mo) with UAO (n = 7) or BPD (n = 5) were gathered. The mean clinical CPAP (8 ± 2 cmH2O) was associated with a significant decrease in Poes and Pdi swings. Indeed, Poes swing decreased from 31 ± 15 cmH2O during spontaneous breathing to 21 ± 10 cmH2O during CPAP (P < 0.05). The mean physiological CPAP level was 2 ± 2 cmH2O higher than the mean clinical CPAP level and was associated with a significantly greater improvement in all indices of respiratory effort (Poes swing 11 ± 5 cm H2O; P < 0.05 compared to clinical CPAP). Expiratory abdominal activity was present during the clinical CPAP and decreased during physiological CPAP. Conclusions A physiological setting of noninvasive CPAP, based on the recording of Poes and Pgas, is superior to a clinical setting, based on clinical noninvasive parameters. Expiratory abdominal activity was present during spontaneous breathing and decreased in the physiological CPAP setting. PMID:23889768

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

    PubMed Central

    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 methacholine was assessed using the in vitro living lung slice preparation. Results One week of CPAP increased AW responsiveness to methacholine in male, but not female mice, compared to untreated control animals. The AW hyper-reactivity of male mice persisted for 2 weeks (at P21) after CPAP treatment ended. 4 days of CPAP, however, did not significantly increase AW reactivity. Females also exhibited AW hyper-reactivity at P21, suggesting a delayed response to early (7 days) CPAP treatment. The effects of 7 days of CPAP on hyper-reactivity to methacholine were unique to smaller AWs whereas larger ones were relatively unaffected. Conclusion These data may be important to our understanding of the potential long-term consequences of neonatal CPAP therapy used in the intensive care of preterm infants. PMID:25950451

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

    PubMed

    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

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

    PubMed Central

    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

  2. Advances in Positive Airway Pressure Treatment Modalities for Hypoventilation Syndromes

    PubMed Central

    Combs, Dan; Shetty, Safal; Parthasarathy, Sairam

    2014-01-01

    SYNOPSIS Rationale Positive airway pressure therapy for hypoventilation syndromes can significantly improve health-related quality of life (HR-QOL), healthcare costs, and even mortality. The sleep-disordered breathing in such individuals are quite complex and require sophisticated devices with algorithms that are designed to accurately detect and effectively treat respiratory events that includes hypoventilation, upper airway obstruction, lower airway obstruction, central apneas and central hypopneas and reduce the work of breathing while maintaining breathing comfort. Objectives The therapeutic physiological rationale for the various advanced PAP modalities and the details about the principles of operation and technology implementation are provided here. Conclusions The physiological rationale for advanced PAP modalities is sound considering the complexity of sleep-disordered breathing in patients with hypoventilation syndromes. Although such devices are increasingly used in clinical practice, the supporting clinical evidence – specifically comparative-effectiveness studies in real-life conditions -- needs to be performed. Moreover, there is much opportunity for further refining these devices that include the ability of the device to reliably monitor gas-exchange, sleep-wakefulness state, and for reducing variability in device efficacy due to provider-selected device-settings. PMID:25346650

  3. Continuous positive airway pressure: Physiology and comparison of devices.

    PubMed

    Gupta, Samir; Donn, Steven M

    2016-06-01

    Nasal continuous positive airway pressure (CPAP) is increasingly used for respiratory support in preterm babies at birth and after extubation from mechanical ventilation. Various CPAP devices are available for use that can be broadly grouped into continuous flow and variable flow. There are potential physiologic differences between these CPAP systems and the choice of a CPAP device is too often guided by individual expertise and experience rather than by evidence. When interpreting the evidence clinicians should take into account the pressure generation sources, nasal interface, and the factors affecting the delivery of pressure, such as mouth position and respiratory drive. With increasing use of these devices, better monitoring techniques are required to assess the efficacy and early recognition of babies who are failing and in need of escalated support. PMID:26948884

  4. Vascular tracers alter hemodynamics and airway pressure in anesthetized sheep

    SciTech Connect

    Albertine, K.H.; Staub, N.C.

    1986-11-01

    The technique of vascular labeling was developed to mark sites of increased microvascular permeability. We used the vascular labeling technique in anesthetized sheep and found that hemodynamics and airway pressure were adversely affected by intraarterial infusions of two vascular tracers. Monastral blue (nine sheep) immediately caused systemic arterial hypotension, pulmonary arterial hypertension, and bronchoconstriction. All three physiological responses were partially blocked by a cyclooxygenase inhibitor (indomethacin) but not by an H1-antihistamine (chlorpheniramine). Colloidal gold (nine sheep) caused immediate, but less dramatic, pulmonary arterial hypertension which was not attenuated by the blocking agents. We conclude that these two vascular tracers caused detrimental physiological side effects in sheep at the usual doses used to label injured microvessels in other species.

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

    PubMed

    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

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

    PubMed

    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

  7. Strategies for the prevention of continuous positive airway pressure failure.

    PubMed

    Sahni, Rakesh; Schiaratura, Maria; Polin, Richard A

    2016-06-01

    Progress in neonatal intensive care is closely linked to improvements in the management of respiratory failure in preterm infants. Current modalities of respiratory support range from the more benign continuous positive airway pressure (CPAP) to various modes of mechanical ventilation. Data from recent randomized control trials suggest that the use of nasal (n)CPAP as the initial mode of respiratory support in critically ill very low birth weight infants is associated with a lower incidence of chronic lung disease. The practice of early initiation of nasal-prong CPAP in all spontaneously breathing infants at Columbia University has resulted in very low rates of chronic lung disease for decades. Many institutions have attempted to replicate the practices and results at Columbia University. However, success rates with nCPAP are highly variable, which may in part be attributable to how well it is utilized. With recent renewed interest in non-invasive respiratory support, particularly bubble nCPAP, it is essential to evaluate strategies for the prevention of CPAP failure. This review discusses strategies that address these issues and shares the practical aspects for replicating success with bubble nCPAP. In addition, it reviews desirable features, major components, and physiological consequences of various bubble CPAP systems along with clinical experience of CPAP use. PMID:26936186

  8. Use of nasal continuous positive airway pressure during neonatal transfers

    PubMed Central

    Bomont, R K; Cheema, I U

    2006-01-01

    Objective To review all cases in which nasal continuous positive airway pressure (CPAP) was used as a means of respiratory support during land based ambulance transfers by a regional neonatal transport service. Design Retrospective study based on review of transport records. Results A total of 1175 transfer requests were received over the 21 month period. The infant in 163 of these cases was receiving nasal CPAP. Ninety two referrals were accepted by the doctor/nurse practitioner led team. Of these, 84 were transported while receiving nasal CPAP. Intervention during transport was required in three of these cases. Fifty five referrals were accepted by the nurse led team. Of these, 16 were transported while receiving nasal CPAP. Intervention was required in two cases. Conclusion There is a small but significant demand for transferring infants who are receiving nasal CPAP. Nasal CPAP appears to be a safe method of respiratory support for a carefully selected group of infants during land based ambulance transfers. PMID:16204357

  9. Submental negative pressure application decreases collapsibility of the passive pharyngeal airway in nonobese women.

    PubMed

    Kato, Shinichiro; Isono, Shiroh; Amemiya, Megumi; Sato, Shin; Ikeda, Aya; Okazaki, Junko; Sato, Yumi; Ishikawa, Teruhiko

    2015-04-01

    The pharyngeal airway is surrounded by soft tissues that are also enclosed by bony structures such as the mandible, maxilla, and cervical spine. The passive pharyngeal airway is therefore structurally analogous to a collapsible tube within a rigid box. Cross-sectional area of the tube is determined by transmural pressure, the pressure difference between intraluminal and extraluminal pressures. Due to a lack of knowledge on the influence of extraluminal soft tissue pressure on the human pharyngeal airway patency, we hypothesized that application of negative external pressure to the submental region decreases collapsibility of the passive pharynx, and that obese individuals have less response to the intervention than nonobese individuals. Static mechanical properties of the passive pharynx were compared before and during application of submental negative pressure in 10 obese and 10 nonobese adult women under general anesthesia and paralysis. Negative pressure was applied through use of a silicone collar covering the entire submental region and a vacuum pump. In nonobese subjects, application of submental negative pressure (-25 and -50 cmH2O) significantly decreased closing pressures at the retropalatal airway by 2.3 ± 3.2 cmH2O and 2.0 ± 3.0 cmH2O, respectively, and at the retroglossal airway by 2.9 ± 2.7 cmH2O and 3.7 ± 2.6 cmH2O, respectively, and the intervention stiffened the retroglossal pharyngeal airway wall. No significant mechanical changes were observed during application of submental negative pressure in obese subjects. Conclusively, application of submental negative pressure was found to decreases collapsibility of the passive pharyngeal airway in nonobese Japanese women. PMID:25614595

  10. A system to generate simultaneous forced oscillation and continuous positive airway pressure.

    PubMed

    Farré, R; Rotger, M; Montserrat, J M; Navajas, D

    1997-06-01

    Assessment of airway obstruction in patients with obstructive sleep apnoea (OSA) subjected to continuous positive airway pressure (CPAP) may be carried out using the forced oscillation technique (FOT). To facilitate routine application of forced oscillation (FO) in sleep studies, our aim was to design a system capable of generating CPAP and applying FOT simultaneously. We constructed a prototype CPAP + FO generator by connecting a specially designed electromagnetic valve in parallel with a conventional blower. The capacity of the prototype to generate forced oscillation (5 Hz +/- 1 hPa) was tested by connecting it to a model simulating spontaneous breathing. The response of the prototype for target CPAPs of 5, 10 and 15 hPa and imposed sinusoidal breathing with peak flow up to 0.75 L x s(-1) was excellent when compared with that reported for commercially available CPAP generators. The applicability of the prototype was tested by applying it to assess airway obstruction in four patients with OSA during sleep. We conclude that the generator designed is able to apply continuous positive airway pressure and forced oscillation simultaneously. The system could be useful for automatic and noninvasive assessment of airway obstruction in patients with obstructive sleep apnoea subjected to continuous positive airway pressure. Future development of the generator may be helpful in implementing a set-up for automatic titration of continuous positive airway pressure. PMID:9192942

  11. Nasal high-flow therapy delivers low level positive airway pressure

    PubMed Central

    Parke, R.; McGuinness, S.; Eccleston, M.

    2009-01-01

    Background The aim of this prospective study was to determine whether a level of positive airway pressure was generated in participants receiving nasal high flow (NHF) delivered by the Optiflow™ system (Fisher and Paykel Healthcare Ltd, Auckland, New Zealand) in a cardiothoracic and vascular intensive care unit (ICU). Methods Nasopharyngeal airway pressure was measured in 15 postoperative cardiac surgery adult patients who received both NHF and standard facemask therapy at a flow rate of 35 litre min−1. Measurements were repeated in the open mouth and closed mouth positions. Mean airway pressure was determined by averaging the pressures at the peak of inspiration of each breath within a 1 min period, allowing the entire pressure profile of each breath to be included within the calculation. Results Low level positive pressure was demonstrated with NHF at 35 litre min−1 with mouth closed when compared with a facemask. NHF generated a mean nasopharyngeal airway pressure of mean (sd) 2.7 (1.04) cm H2O with the mouth closed. Airway pressure was significantly higher when breathing with mouth closed compared with mouth open (P≤0.0001). Conclusions This study demonstrated that a low level of positive pressure was generated with NHF at 35 litre min−1 of gas flow. This is consistent with results obtained in healthy volunteers. Australian Clinical Trials Registry www.actr.org.au ACTRN012606000139572. PMID:19846404

  12. [Invasive ventilation. Classification, technique and clinical experiences with BiPAP/APRV (Biphasic Positive Airway Pressure/Airway Pressure Release Ventilation)].

    PubMed

    Antonsen, K; Jacobsen, E; Pedersen, J E; Porsborg, P A; Bonde, J

    1996-01-22

    BiPAP (bilevel or biphasic positive airway pressure) and APRV (airway pressure release ventilation) are new, and from a technical viewpoint closely related techniques recently introduced to the field of invasive ventilatory support. BiPAP/APRV can be described as a pressure controlled continuous high flow positive airway pressure system with a time-cycled change between a high inspiratory pressure level and a lower expiratory pressure level. Due to highly sensitive valves placed in the inspiratory and expiratory part of the system, unrestricted spontaneous breathing is possible at any moment of the mechanically supported ventilatory cycle. During invasive ventilation BiPAP offers potential advantages by allowing unrestricted spontaneous breathing thus reducing the need for sedation and facilitating weaning. APRV has primarily been investigated in conditions of moderate to severe acute lung injury and it seems that APRV is associated with less detrimental effects on the cardiopulmonary system compared to conventional ventilatory strategies. Apart from a review of the literature the article gives a classification and a technical description of the systems and focuses on the practical approach to BiPAP/APRV, e.g. the initiation and adjustment of respiratory support and the weaning from ventilatory support when applying these techniques. PMID:8638300

  13. 3D mapping of airway wall thickening in asthma with MSCT: a level set approach

    NASA Astrophysics Data System (ADS)

    Fetita, Catalin; Brillet, Pierre-Yves; Hartley, Ruth; Grenier, Philippe A.; Brightling, Christopher

    2014-03-01

    Assessing the airway wall thickness in multi slice computed tomography (MSCT) as image marker for airway disease phenotyping such asthma and COPD is a current trend and challenge for the scientific community working in lung imaging. This paper addresses the same problem from a different point of view: considering the expected wall thickness-to-lumen-radius ratio for a normal subject as known and constant throughout the whole airway tree, the aim is to build up a 3D map of airway wall regions of larger thickness and to define an overall score able to highlight a pathological status. In this respect, the local dimension (caliber) of the previously segmented airway lumen is obtained on each point by exploiting the granulometry morphological operator. A level set function is defined based on this caliber information and on the expected wall thickness ratio, which allows obtaining a good estimate of the airway wall throughout all segmented lumen generations. Next, the vascular (or mediastinal dense tissue) contact regions are automatically detected and excluded from analysis. For the remaining airway wall border points, the real wall thickness is estimated based on the tissue density analysis in the airway radial direction; thick wall points are highlighted on a 3D representation of the airways and several quantification scores are defined. The proposed approach is fully automatic and was evaluated (proof of concept) on a patient selection coming from different databases including mild, severe asthmatics and normal cases. This preliminary evaluation confirms the discriminative power of the proposed approach regarding different phenotypes and is currently extending to larger cohorts.

  14. Effect of geometric variations on pressure loss for a model bifurcation of the human lung airway.

    PubMed

    Kang, Min-Yeong; Hwang, Jeongeun; Lee, Jin-Won

    2011-04-01

    Characteristics of pressure loss (ΔP) in human lung airways were numerically investigated using a realistic model bifurcation. Flow equations were numerically solved for the steady inspiratory condition with the tube length, the branching angle and flow velocity being varied over a wide range. In general, the ΔP coefficient K showed a power-law dependence on Reynolds number (Re) and length-to-diameter ratio with a different exponent for Re≥100 than for Re<100. The effect of different branching angles on pressure loss was very weak in the smooth-branching airways. PMID:21354574

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

    PubMed Central

    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

  16. Effects of upper airway pressure on abdominal muscle activity in conscious dogs.

    PubMed

    Plowman, L; Lauff, D C; McNamara, F; Berthon-Jones, M; Sullivan, C E

    1991-12-01

    We have examined arousal and abdominal muscle electromyogram (EMGabd) responses to upper airway pressure stimuli during physiological sleep in four dogs with permanent side-hole tracheal stomata. The dogs were trained to sleep with a tightly fitting snout mask, hermetically sealed in place, while breathing through a cuffed endotracheal tube inserted through the tracheostomy. Sleep stage was determined by behavioral and electroencephalographic criteria. EMGabd activity was measured using bipolar fine-wire electrodes inserted into the abdominal muscle layers. Static increases or decreases in upper airway pressure (+/- 6 cmH2O), when applied at the snout mask or larynx (upper trachea), caused an immediate decrease in EMGabd on the first two to three breaths; EMGabd usually returned to control levels within the 1-min test interval. In contrast, oscillatory pressure waves at 30 Hz and +/- 3 cmH2O amplitude (or -2 to -8 cmH2O amplitude) produced an immediate and sustained reduction in IMGabd in all sleep states. Inhibition of EMGabd could be maintained over many minutes when the oscillatory pressure stimulus was pulsed by using a cycle of 0.5 s on and 0.5 s off. Oscillatory upper airway pressures were also found to be powerful arousal-promoting stimuli, producing arousal in 94% of tests in drowsiness and 66% of tests in slowwave sleep. The results demonstrate the presence of breath-by-breath upper airway control of abdominal muscle activity. PMID:1778951

  17. Simultaneous Luminescence Pressure and Temperature Mapping

    NASA Technical Reports Server (NTRS)

    Buck, Gregory M. (Inventor)

    1998-01-01

    A simultaneous luminescence pressure and temperature mapping system is developed including improved dye application techniques for surface temperature and pressure measurements from 5 torr to 1000 torr with possible upgrade to from 0.5 torr to several atmospheres with improved camera resolution. Adsorbed perylene dye on slip-cast silica is pressure (oxygen) sensitive and reusable to relatively high temperatures (-150 C). Adsorbed luminescence has an approximately linear color shift with temperature, which can be used for independent temperature mapping and brightness pressure calibration with temperature.

  18. Simultaneous Luminescence Pressure and Temperature Mapping System

    NASA Technical Reports Server (NTRS)

    Buck, Gregory M. (Inventor)

    1995-01-01

    A simultaneous luminescence pressure and temperature mapping system is developed including improved dye application techniques for surface temperature and pressure measurements from 5 torr to 1000 torr with possible upgrade to from 0.5 torr to several atmospheres with improved camera resolution. Adsorbed perylene dye on slip-cast silica is pressure (oxygen) sensitive and reusable to relatively high temperatures (approximately 150 C). Adsorbed luminescence has an approximately linear color shift with temperature, which can be used for independent temperature mapping and brightness pressure calibration with temperature.

  19. Characteristics of the upper airway pressure-flow relationship during sleep.

    PubMed

    Hudgel, D W; Hendricks, C; Hamilton, H B

    1988-05-01

    In examining the mechanical properties of the respiratory system during sleep in healthy humans, we observed that the inspiratory pressure-flow relationship of the upper airway was often flow limited and too curvilinear to be predicted by the Rohrer equation. The purposes of this study were 1) to describe a mathematical model that would better define the inspiratory pressure-flow relationship of the upper airway during sleep and 2) to identify the segment of airway responsible for the sleep-related flow limitation. We measured nasal and total supralaryngeal pressure and flow during wakefulness and stage 2 sleep in five healthy male subjects lying supine. A right rectangular hyperbolic equation, V = (alpha P)/(beta + P), where V is flow, P is pressure, alpha is an asymptote for peak flow, and beta is pressure at a flow of alpha/2, was used in its linear form, P/V = (beta/alpha) + (P/alpha). The goodness of fit of the new equation was compared with that for the linearized Rohrer equation P/V = K1 + K2V. During wakefulness the fit of the hyperbolic equation to the actual pressure-flow data was equivalent to or significantly better than that for the Rohrer equation. During sleep the fit of the hyperbolic equation was superior to that for the Rohrer equation. For the whole supralaryngeal airway during sleep, the correlation coefficient for the hyperbolic equation was 0.90 +/- 0.50, and for the Rohrer equation it was 0.49 +/- 0.25. The flow-limiting segment was located within the pharyngeal airway, not in the nose.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3391893

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

    ERIC Educational Resources Information Center

    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…

  1. Hurler's syndrome with cor pulmonale secondary to obstructive sleep apnoea treated by continuous positive airway pressure.

    PubMed

    Chan, D; Li, A M; Yam, M C; Li, C K; Fok, T F

    2003-01-01

    A 6-year-old boy with Hurler's syndrome presented with right heart failure and pulmonary hypertension secondary to severe obstructive sleep apnoea. Both his sleep apnoea and cor pulmonale were effectively controlled with continuous positive airway pressure therapy. PMID:12969215

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

    PubMed Central

    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 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 PAP device

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

    PubMed

    Vérin, E; Similowski, T; Sériès, F

    2003-01-01

    Continuous positive airway pressure (CPAP) is the main treatment of the obstructive sleep apnoea syndrome (OSAS). We assessed its effects on the upper airway (UA) dynamics in response to bilateral anterior magnetic phrenic nerve stimulation (BAMPS) in 17 awake untreated OSAS patients (15 males; 52 +/- 7 years) whose effective CPAP (P(eff)) had been determined beforehand by a conventional titration sleep study. All twitch-related inspirations were flow-limited, flow first rising to a maximum (V(Imax)), then decreasing to a minimum (V(Imin)), and then increasing again (M-shaped pattern). Up to V(Imin), the relationship between driving pressure (P(d)) and flow (V) could adequately be fitted to a polynomial regression model (V = k(1)P(d) + k(2)P(d)(2); r(2) = 0.71-0.98, P < 0.0001). At atmospheric pressure V(Imax) was 700 +/- 377 ml s(-1), V(Imin) was 458 +/- 306 ml s(-1), k(1) was 154.5 +/- 63.9 ml s(-1) (cmH(2)O)(-1), and k(2) was 10.7 +/- 7.3 ml s(-1) (cmH(2)O)(-1). CPAP significantly increased V(Imax) and V(Imin) (peak values 1007 +/- 332 ml and 837 +/- 264 ml s(-1), respectively) as well as k(1) and k(2) (peak values 300.9 +/- 178.2 ml s(-1) (cmH(2)O)(-1) and 55.2 +/- 65.3 ml s(-1) (cmH(2)O)(-1), respectively). With increasing CPAP, k(1)/k(2) increased up to a peak value before decreasing. We defined as P(eff,stim) the CPAP value corresponding to the highest k(1)/k(2) value. P(eff,stim) was correlated with P(eff) (P(eff) = 7.0 +/- 2.0; P(eff,stim) = 6.4 +/- 2.6 cmH(2)O; r = 0.886; 95 % CI 0.696-0.960, P < 0.001). We conclude that CPAP improves UA dynamics in OSAS and that the therapeutic CPAP to apply can be predicted during wakefulness using BAMPS. PMID:12509495

  4. New developments in the use of positive airway pressure for obstructive sleep apnea

    PubMed Central

    Boeder, Schafer; Malhotra, Atul; Patel, Sanjay R.

    2015-01-01

    Obstructive sleep apnea (OSA) is a disorder which afflicts a large number of individuals around the world. OSA causes sleepiness and is a major cardiovascular risk factor. Since its inception in the early 1980’s, continuous positive airway pressure (CPAP) has emerged as the major treatment of OSA, and it has been shown to improve sleepiness, hypertension, and a number of cardiovascular indices. Despite its successes, adherence with treatment remains a major limitation. Herein we will review the evidence behind the use of positive airway pressure (PAP) therapy, its various modes, and the methods employed to improve adherence. We will also discuss the future of PAP therapy in OSA and personalization of care. PMID:26380760

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

    PubMed

    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

  6. Effect of epithelium ATP release on cyclic pressure-induced airway mucus secretion

    PubMed Central

    Tong, Jin; Zhou, Xiang-dong; Perelman, Juliy M.; Kolosov, Victor P.

    2013-01-01

    The cyclic mechanical effect of airflow during breathing creates the optimal airway hydration state. MUC (mucin) 5AC is an important component of the airway mucus. The formation of MUC5AC is related to ATP and intracellular calcium in the epithelial cells. In this study, we evaluated the effect of ATP release from intracellular calcium in epithelial cells on cyclic pressure-induced mucus secretion in the airway. 16HBE (human bronchial epithelial cells) were cultured in vitro on cyclically tilted cultured plates and divided into five groups: control, tilt, tilt and BAPTA–AM (1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid–acetoxymethyl ester), tilt and EGTA and tilt and RB-2 (reactive blue-2). The shear stress and compressive stress were induced by the surface tension of the liquid, atmospheric pressure and liquid gravity. Cell activity, MUC5AC mRNA expression level, MUC5AC protein expression level and ATP release and intracellular calcium changes were measured with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay, RT–PCR (reverse transcription–PCR), HPLC and inverted fluorescence microscope, respectively. We detected that cyclic pressure significantly increased MUC5AC secretion and ATP release. The enhanced ATP release could be inhibited by both BAPTA–AM and RB-2, while EGTA did not have a suppressive effect. BAPTA–AM, EGTA and RB-2 did not obviously inhibit MUC5AC mRNA expression. Cyclic pressure did not induce MUC5AC secretion in the airway mucus epithelium via Ca2+-dependent ATP release, and nearly all Ca2+ was provided by stored intracellular Ca2+. PMID:24329423

  7. Effect of epithelium ATP release on cyclic pressure-induced airway mucus secretion.

    PubMed

    Tong, Jin; Zhou, Xiang-Dong; Perelman, Juliy M; Kolosov, Victor P

    2013-12-16

    The cyclic mechanical effect of airflow during breathing creates the optimal airway hydration state. Mucin (MUC) 5AC is an impotent component of the airway mucus. The formation of MUC5AC is related to adenosine triphosphate (ATP) and intracellular calciumin the epithelial cells. In this study, we evaluated the effect of ATP release from and intracellular calcium in epithelial cells on cyclic pressure-induced mucus secretion in the airway. Human bronchial epithelial cells (16HBE) were cultured in vitro on cyclically tilted cultured plates and divided into 5 groups: control, tilt, tilt and BAPTA-AM, tilt and EGTA, and tilt and RB-2. The shear stress and compressive stress were induced by the surface tension of the liquid, atmospheric pressure and liquid gravity. Cell activity, MUC5AC mRNA expression level, MUC5AC protein expression level and ATP release, and intracellular calcium changes were measured with the MTT assay, RT-PCR, high performance liquid chromatography (HPLC) and inverted fluorescence microscope, respectively. We detected that cyclic pressure significantly increased MUC5AC secretion and ATP release. The enhanced ATP release could be inhibited by both BAPTA-AM and RB-2, while EGTA did not have a suppressive effect. BAPTA-AM, EGTA, and RB-2 did not obviously inhibit MUC5AC mRNA expression.Cyclic pressure did not induce MUC5AC secretion in the airway mucus epithelium via Ca2+-dependent ATP release, and nearly all Ca2+ was provided by stored intracellular Ca2+. PMID:24329423

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

    PubMed

    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

  9. Negative Expiratory Pressure Technique: An Awake Test to Measure Upper Airway Collapsibility in Adolescents

    PubMed Central

    Carrera, Helena Larramona; Marcus, Carole L.; McDonough, Joseph M.; Morera, Joan C. Oliva; Huang, Jingtao; Farre, Ramon; Montserrat, Josep M.

    2015-01-01

    Study Objectives: Upper airway (UA) collapsibility is a major pathophysiologic feature of the obstructive sleep apnea syndrome (OSAS). In adolescents, it is measured by obtaining the slope of pressure-flow relationship (SPF) while applying negative nasal pressure during sleep. An easier technique to assess UA collapsibility, consisting of application of negative expiratory pressure (NEP) during wakefulness, has demonstrated differences between control and OSAS subjects. We hypothesized that the NEP technique would correlate with SPF as a measurement of UA collapsibility in adolescents. Design: During wakefulness, NEP of −5 cm H2O in the seated and supine position was applied during the first second of expiration. The area under the expiratory flow-volume curve during NEP was compared to tidal breathing (RatioNEP). In addition, adolescents underwent SPF measurements during sleep. Two SPF techniques were performed to measure the activated and relatively hypotonic UA. Setting: Pediatric sleep laboratory. Participants: Seven adolescents with OSAS and 20 controls. Results: In the seated position, there was a correlation between RatioNEP and both hypotonic SPF (r = −0.39, P = 0.04) and activated SPF (r = −0.62, P = 0.001). In the supine position, there was a correlation between RatioNEP and activated SPF (r = −0.43, P = 0.03) and a trend for hypotonic SPF (r = −0.38, P = 0.06). Conclusions: The negative expiratory pressure (NEP) technique correlates with the hypotonic and activated slope of pressure-flow relationship measurements. The seated position showed the strongest correlation. The NEP technique can be used as an alternative method to evaluate upper airway collapsibility in adolescents. Citation: Carrera HL, Marcus CL, McDonough JM, Morera JC, Huang J, Farre R, Montserrat JM. Negative expiratory pressure technique: an awake test to measure upper airway collapsibility in adolescents. SLEEP 2015;38(11):1783–1791. PMID:26158888

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

    PubMed

    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

  11. [BiPAP (Biphasic Positive Airway Pressure)--an apparatus for non-invasive respiratory support].

    PubMed

    Nørregaard, F O; Vindelev, P O; Juhl, B

    1996-01-22

    Ventilatory support to patients suffering from respiratory insufficiency using a non-invasive technique has gained increasing popularity during the last few years. BiPAP (biphasic positive airway pressure) (Respiconics) offers inspiratory support and expiratory resistance to this group of patients both in the hospital and, in particular, in the home. The apparatus has proven to be effective as for instance a long term support device for patients suffering from neuromuscular diseases, sleep apnoeas and during the postoperative period. It works without pressurized air and is portable. PMID:8638299

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

    PubMed Central

    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

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

    PubMed

    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

  14. Impact of Continuous Positive Airway Pressure on Cardiovascular Risk Factors in High-Risk Patients.

    PubMed

    Zhao, Ying Y; Redline, Susan

    2015-11-01

    Cardiovascular disease remains the leading cause of morbidity and mortality in developed countries. Obstructive sleep apnea is a highly prevalent condition characterized by repetitive upper airway collapse during sleep. A large body of evidence suggests that obstructive sleep apnea is associated with the development of cardiovascular disease and increased cardiovascular morbidity and mortality. Continuous positive airway pressure (CPAP) is the current gold standard for the treatment of obstructive sleep apnea. CPAP devices maintain upper airway patency using a pneumatic splint, thereby ameliorating the repetitive deoxygenation and reoxygenation characteristic of sleep in obstructive sleep apnea patients. Accumulating evidence suggests that CPAP treatment may lead to a reduction in blood pressure. Limited evidence also suggests that CPAP therapy may modulate glucose metabolism, serum cholesterol levels, and inflammatory biomarkers. Thus, CPAP treatment may be associated with cardiovascular risk factor modification in patients with obstructive sleep apnea, who are often obese and at an increased risk of developing cardiovascular disease. This review updates the knowledge on the effects of CPAP on cardiovascular risk factors from recently published randomized trials. PMID:26370408

  15. Bubble Continuous Positive Airway Pressure Enhances Lung Volume and Gas Exchange in Preterm Lambs

    PubMed Central

    Pillow, J. Jane; Hillman, Noah; Moss, Timothy J. M.; Polglase, Graeme; Bold, Geoff; Beaumont, Chris; Ikegami, Machiko; Jobe, Alan H.

    2007-01-01

    Rationale: The technique used to provide continuous positive airway pressure (CPAP) to the newborn may influence lung function and breathing efficiency. Objectives: To compare differences in gas exchange physiology and lung injury resulting from treatment of respiratory distress with either bubble or constant pressure CPAP and to determine if the applied flow influences short-term outcomes. Methods: Lambs (133 d gestation; term is 150 d) born via cesarean section were weighed, intubated, and treated with CPAP for 3 hours. Two groups were treated with 8 L/minute applied flow using the bubble (n = 12) or the constant pressure (n = 12) technique. A third group (n = 10) received the bubble method with 12 L/minute bias flow. Measurements at study completion included arterial blood gases, oxygraphy, capnography, tidal flow, multiple breath washout, lung mechanics, static pressure–volume curves, and bronchoalveolar lavage fluid protein. Measurements and Main Results: Birth weight and arterial gas variables at 15 minutes were comparable. Flow (8 or 12 L/min) did not influence the 3-hour outcomes in the bubble group. Bubble technique was associated with a higher pH, PaO2, oxygen uptake, and area under the flow–volume curve, and a decreased alveolar protein, respiratory quotient, PaCO2, and ventilation inhomogeneity compared with the constant pressure group. Conclusions: Compared with constant pressure technique, bubble CPAP promotes enhanced airway patency during treatment of acute postnatal respiratory disease in preterm lambs and may offer protection against lung injury. PMID:17431223

  16. Surface pressure field mapping using luminescent coatings

    NASA Technical Reports Server (NTRS)

    Mclachlan, B. G.; Kavandi, J. L.; Callis, J. B.; Gouterman, M.; Green, E.; Khalil, G.; Burns, D.

    1993-01-01

    In recent experiments we demonstrated the feasibility of using the oxygen dependence of luminescent molecules for surface pressure measurement in aerodynamic testing. This technique is based on the observation that for many luminescent molecules the light emitted increases as the oxygen partial pressure, and thus the air pressure, the molecules see decreases. In practice the surface to be observed is coated with an oxygen permeable polymer containing a luminescent molecule and illuminated with ultraviolet radiation. The airflow induced surface pressure field is seen as a luminescence intensity distribution which can be measured using quantitative video techniques. Computer processing converts the video data into a map of the surface pressure field. The experiments consisted of evaluating a trial luminescent coating in measuring the static surface pressure field over a two-dimensional NACA-0012 section model airfoil for Mach numbers ranging from 0.3 and 0.66. Comparison of the luminescent coating derived pressures were made to those obtained from conventional pressure taps. The method along with the experiment and its results will be described.

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

    PubMed

    Johnson, Karin Gardner; Johnson, Douglas Clark

    2015-01-01

    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. PMID:26604837

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

    PubMed Central

    Johnson, Karin Gardner; Johnson, Douglas Clark

    2015-01-01

    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. PMID:26604837

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

    PubMed

    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

  20. Effects of the components of positive airway pressure on work of breathing during bronchospasm

    PubMed Central

    Miro, Adelaida M; Pinsky, Michael R; Rogers, Paul L

    2004-01-01

    Introduction Partial assist ventilation reduces work of breathing in patients with bronchospasm; however, it is not clear which components of the ventilatory cycle contribute to this process. Theoretically, expiratory positive airway pressure (EPAP), by reducing expiratory breaking, may be as important as inspiratory positive airway pressure (IPAP) in reducing work of breathing during acute bronchospasm. Method We compared the effects of 10 cmH2O of IPAP, EPAP, and continuous positive airwaypressure (CPAP) on inspiratory work of breathing and end-expiratory lung volume (EELV) in a canine model of methacholine-induced bronchospasm. Results Methacholine infusion increased airway resistance and work of breathing. During bronchospasm IPAP and CPAP reduced work of breathing primarily through reductions in transdiaphragmatic pressure per tidal volume (from 69.4 ± 10.8 cmH2O/l to 45.6 ± 5.9 cmH2O/l and to 36.9 ± 4.6 cmH2O/l, respectively; P < 0.05) and in diaphragmatic pressure–time product (from 306 ± 31 to 268 ± 25 and to 224 ± 23, respectively; P < 0.05). Pleural pressure indices of work of breathing were not reduced by IPAP and CPAP. EPAP significantly increased all pleural and transdiaphragmatic work of breathing indices. CPAP and EPAP similarly increased EELV above control by 93 ± 16 ml and 69 ± 12 ml, respectively. The increase in EELV by IPAP of 48 ± 8 ml (P < 0.01) was significantly less than that by CPAP and EPAP. Conclusion The reduction in work of breathing during bronchospasm is primarily induced by the IPAP component, and that for the same reduction in work of breathing by CPAP, EELV increases more. PMID:15025781

  1. [The numerical simulation of the internal flow field inside the pressure generator of a continuous positive airway pressure ventilator].

    PubMed

    Cheng, Yunzhang; Zhu, Lihua; Zhang, Weiguo; Wu, Wenquan

    2011-12-01

    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-epsilon 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. PMID:22295700

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

    PubMed

    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

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

    PubMed Central

    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

  4. Behavioral training for increasing preschool children's adherence with positive airway pressure: a preliminary study.

    PubMed

    Slifer, Keith J; Kruglak, Deborah; Benore, Ethan; Bellipanni, Kimberly; Falk, Lroi; Halbower, Ann C; Amari, Adrianna; Beck, Melissa

    2007-01-01

    Behavioral training was implemented to increase adherence with positive airway pressure (PAP) in 4 preschool children. The training employed distraction, counterconditioning, graduated exposure, differential reinforcement, and escape extinction. A non-concurrent multiple baseline experimental design was used to demonstrate program effects. Initially, the children displayed distress and escape-avoidance behavior when PAP was attempted. With training, all 4 children tolerated PAP while sleeping for age appropriate durations. For the 3 children with home follow-up data, the parents maintained benefits. The results are discussed in relation to behavior principles, child health, and common barriers to PAP adherence. PMID:17441784

  5. Prolonged respiratory illness after single overnight continuous positive airway pressure humidification: endotoxin as the suspect.

    PubMed

    Raymond, Lawrence W; Barkley, John E; Langley, Ricky; Sautter, Robert

    2009-12-01

    A patient developed a prolonged respiratory illness after a single overnight use of tap water to humidify air supplied by a constant positive airway pressure (CPAP) device, which she had previously used for six years without difficulty. During those years, she used only distilled water for this purpose, as instructed by her sleep specialist. Analysis of the well water supplying her home showed no microorganisms, metals or other analytes likely to have caused her illness, but endotoxin was found at concentrations well above that recommended by the U.S. Pharmacopeia, as a maximum in water which may be inhaled as an aerosol. PMID:20016436

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

    PubMed

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

    2016-09-01

    Excessive daytime sleepiness (EDS) is common in obstructive sleep apnea (OSA), but it is also common in the general population. When sleepiness remains after continuous positive airway pressure (CPAP) treatment of OSA, comorbid conditions or permanent brain injury before CPAP therapy may be the cause of the residual sleepiness. There is currently no broad approach to treating residual EDS in patients with OSA. Individual assessment must be made of comorbid conditions and medications, and of lifestyle factors that may be contributing to the sleepiness. Modafinil and armodafinil are the only pharmacologic agents indicated for residual sleepiness in these patients. PMID:27542881

  7. Early airway pressure release ventilation prevents ARDS-a novel preventive approach to lung injury.

    PubMed

    Roy, Shreyas; Habashi, Nader; Sadowitz, Benjamin; Andrews, Penny; Ge, Lin; Wang, Guirong; Roy, Preyas; Ghosh, Auyon; Kuhn, Michael; Satalin, Joshua; Gatto, Louis A; Lin, Xin; Dean, David A; Vodovotz, Yoram; Nieman, Gary

    2013-01-01

    Acute respiratory distress syndrome (ARDS) afflicts 200,000 patients annually with a mortality rate of 30% to 60% despite wide use of low tidal volume (LTV) ventilation, the present standard of care. High-permeability alveolar edema and instability occur early in the development of ARDS, before clinical signs of lung injury, and represent potential targets for therapy. We hypothesize that early application of a protective ventilation strategy (airway pressure release ventilation [APRV]) will stabilize alveoli and reduce alveolar edema, preventing the development of ARDS. Yorkshire pigs (30-40 kg) were anesthetized and subjected to two-hit injury: (a) intestinal ischemia-reperfusion, (b) peritoneal sepsis, or sham surgery. Following surgery, pigs were randomized into APRV (n = 4), according to current published guidelines for APRV; LTV ventilation (n = 3), using the current published ARDS Network guidelines (6 mL/kg); or sham (n = 5). The clinical care of all pigs was administered per the Surviving Sepsis Campaign guidelines. Animals were killed, and necropsy performed at 48 h. Arterial blood gases were measured to assess for the development of clinical lung injury. Lung tissue epithelial cadherin (E-cadherin) was measured to assess alveolar permeability. Bronchoalveolar lavage fluid (BALF) surfactant protein A was measured to assess alveolar stability. Lung edema content and histopathology were analyzed at 48 h. Airway pressure release ventilation pigs did not develop ARDS. In contrast, pigs in the LTV ventilation met ARDS criteria (PaO2/FIO2 ratio) (APRV: baseline = 471 ± 16; 48 h = 392 ± 8; vs. LTV ventilation: baseline = 551 ± 28; 48 h = 138 ± 88; P < 0.001). Airway pressure release ventilation preserved alveolar epithelial integrity demonstrated by higher levels of E-cadherin in lung tissue as compared with LTV ventilation (P < 0.05). Surfactant protein A levels were higher in BALF from the APRV group, suggesting APRV preserved alveolar stability

  8. Bubble continuous positive airway pressure in a human immunodeficiency virus-infected infant

    PubMed Central

    McCollum, E. D.; Smith, A.; Golitko, C. L.

    2014-01-01

    SUMMARY World Health Organization-classified very severe pneumonia due to Pneumocystis jirovecii infection is recognized as a life-threatening condition in human immunodeficiency virus (HIV) infected infants. We recount the use of nasal bubble continuous positive airway pressure (BCPAP) in an HIV-infected African infant with very severe pneumonia and treatment failure due to suspected infection with P. jirovecii. We also examine the potential implications of BCPAP use in resource-poor settings with a high case index of acute respiratory failure due to HIV-related pneumonia, but limited access to mechanical ventilation. PMID:21396221

  9. Computer simulations of pressure and velocity fields in a human upper airway during sneezing.

    PubMed

    Rahiminejad, Mohammad; Haghighi, Abdalrahman; Dastan, Alireza; Abouali, Omid; Farid, Mehrdad; Ahmadi, Goodarz

    2016-04-01

    In this paper, the airflow field including the velocity, pressure and turbulence intensity distributions during sneezing of a female subject was simulated using a computational fluid dynamics model of realistic upper airways including both oral and nasal cavities. The effects of variation of reaction of the subject during sneezing were also investigated. That is, the impacts of holding the nose or closing the mouth during sneezing on the pressure and velocity distributions were studied. Few works have studied the sneeze and therefore different aspects of this phenomenon have remained unknown. To cover more possibilities about the inlet condition of trachea in different sneeze scenarios, it was assumed that the suppressed sneeze happens with either the same inlet pressure or the same flow rate as the normal sneeze. The simulation results showed that during a normal sneeze, the pressure in the trachea reaches about 7000Pa, which is much higher than the pressure level of about 200Pa during the high activity exhalation. In addition, the results showed that, suppressing the sneeze by holding the nose or mouth leads to a noticeable increase in pressure difference in the tract. This increase was about 5 to 24 times of that during a normal sneeze. This significant rise in the pressure can justify some reported damage due to suppressing a sneeze. PMID:26914240

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

    PubMed Central

    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

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

    PubMed

    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. Nasal airway positive pressure in patients with occlusive sleep apnea. Methods and feasibility.

    PubMed

    Remmers, J E; Sterling, J A; Thorarinsson, B; Kuna, S T

    1984-12-01

    Nasal airway positive pressure (NAPP) effectively eliminates obstructive sleep apnea. This report describes construction and evaluation of a convenient NAPP apparatus used successfully in 15 patients with obstructive sleep apnea. An impeller blower with high flow, low pressure characteristics delivers room air to a flow divider and then to an injector attached to a custom-fitted nose mask. Of the total naris pressure supplied by the system, a large fraction derives from the kinetic energy of the air stream delivered to the naris by the injectors. This, together with the high flow rate of the system, promotes a constant naris pressure. Naris pressure is determined by the size of the flow divider and the aperture of the exhaust port(s) of the injector. A series of 10 flow divider-injector combinations are described that provide a variety of naris pressures between 2.5 and 13.6 cm H2O. Fourteen of 15 patients found the NAPP apparatus acceptable and effective. No maintenance or repair appears to be required. PMID:6391309

  13. [Continuous positive airway pressure treatment in sleep-related respiratory disorders in children].

    PubMed

    Estivill Sancho, Eduard; Miró, Núria Roure

    2010-12-01

    Continuous positive airway pressure (CPAP) is the first choice in the treatment of apnea-hypopnea syndrome in adults and, in recent years, is considered the second option after surgery in children. CPAP is the best option in children if apnea-hypopnea syndrome persists after surgery. For many professionals in the field, the use of CPAP in all ages of children and adolescents is safe, effective and well tolerated. Follow-up visits are required every 6-12 months, since the mask pressure and size requirements will change depending on children's growth and development. The success of the use of CPAP is closely related to children's tolerance of the CPAP mask. Many professionals have described strategies to improve this tolerance. One of these strategies is to use behavioral therapy, which has been shown be effective in increasing tolerance and performance of the CPAP. PMID:21354498

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

    PubMed Central

    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 57 (6)) who received continuous positive airway pressure for three months and 16 patients (49(6) apnoeas and hypopnoeas/hour) who received conservative treatment for a similar period. RESULTS--Both groups showed significant within group changes in cognitive function between baseline and three months, but when comparisons were made between groups the only significant difference was a greater improvement in multiple sleep latency with continuous positive airway pressure. However, the improvement in sleep latency with continuous positive airway pressure was relatively small (3.5 (0.5) to 5.6 (0.7) min). The group treated with continuous positive airway pressure was divided into those who complied well with treatment (> 4.5 hours/night) and those who did not. Those who complied well (n = 14) showed significant improvement in mean sleep latency and also in depression score compared with the controls but no greater improvement in cognitive function. CONCLUSION--This study confirms significant improvements in objective sleepiness and mood with continuous positive airway pressure, but shows no evidence of major improvements in cognitive function. PMID:8236074

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

    PubMed Central

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

    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 < 0.01) 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 cmH2O 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

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

    PubMed

    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

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

    PubMed Central

    Petersen, Rebecca Y.; Royse, Emily; Kemp, Matthew W.; Miura, Yuichiro; Noe, Andres; Jobe, Alan H.; Hillman, Noah H.

    2016-01-01

    Background Mechanical ventilation at birth causes airway injury and lung inflammation in preterm sheep. Continuous positive airway pressure (CPAP) is being increasingly used clinically to transition preterm infants at birth. Objective To test if distending pressures will activate acute phase reactants and inflammatory changes in the airways of fetal, preterm lambs. Methods The head and chest of fetal lambs at 128±1 day GA were surgically exteriorized. With placental circulation intact, fetal lambs were then randomized to one of five 15 minute interventions: PEEP of 0, 4, 8, 12, or 16 cmH2O. Recruitment volumes were recorded. Fetal lambs remained on placental support for 30 min after the intervention. The twins of each 0 cmH2O animal served as controls. Fetal lung fluid (FLF), bronchoalveolar lavage fluid (BAL), right mainstem bronchi and peripheral lung tissue were evaluated for inflammation. Results Recruitment volume increased from 0.4±0.04 mL/kg at 4 cmH2O to 2.4±0.3 mL/kg at 16 cmH2O. The lambs were surfactant deficient, and all pressures were below the opening inflection pressure on pressure-volume curve. mRNA expression of early response genes and pro-inflammatory cytokines did not increase in airway tissue or lung tissue at any pressure compared to controls. FLF and BAL also did not have increases in early response proteins. No histologic changes or Egr-1 activation was present at the pressures used. Conclusion Distending pressures as high as 16 cmH2O did not recruit lung volume at birth and did not increase markers of injury in the lung or airways in non-breathing preterm fetal sheep. PMID:27463520

  18. Safety and effectiveness of bubble continuous positive airway pressure in preterm neonates with respiratory distress

    PubMed Central

    Mathai, S.S.; Rajeev, A.; Adhikari, K.M.

    2014-01-01

    Background Studies on Bubble Continuous Positive Airway Pressure (B-CPAP) as respiratory support for neonates are few. The aim of our study was to determine the efficacy and safety of B-CPAP in preterm neonates requiring respiratory support. Methods A prospective observation study was done on 50 preterm babies requiring respiratory support for mild to moderate respiratory distress. Support was given with short, nasal cannulae. Surfactant was administered when indicated. Monitoring was done clinically, with pulse oximeter, radiologically and with blood gases. Staff members were also asked their views. Follow-up was done for 3 months. Results The mean gestational age was 32.46 (+3.23) weeks and mean birth weight 1454.4 (+487.42) g. Respiratory Distress Syndrome was the commonest indication (30/50). The mean maximum pressure was 6.04 cm H2O and mean maximum FiO2 was 72.16%. Mean maximum paO2, paCO2 and mean minimum paCO2 were 92.93 mm Hg (+16.97), 52.36 mm Hg (+ 7.78) and 36.46 mm Hg (+ 4.95) respectively. Early initiation resulted in lesser duration of support. Failure rate was 30%. Apnoea, >1 dose surfactant and late initiation had a statistically higher incidence of failure. Main complications were skin abrasions (30%), feed intolerance (26%) and gastric distension (26%). Survival rate was 94%. 68% of staff felt that it was as easy to use and 88% felt it was more reliable than standard CPAP. Conclusions Bubble Continuous Positive Airway Pressure is safe, efficacious and easy to use in preterm neonates with mild to moderate respiratory distress. PMID:25382905

  19. Impact of Treatment with Continuous Positive Airway Pressure (CPAP) on Weight in Obstructive Sleep Apnea

    PubMed Central

    Quan, Stuart F.; Budhiraja, Rohit; Clarke, Denise P.; Goodwin, James L.; Gottlieb, Daniel J.; Nichols, Deborah A.; Simon, Richard D.; Smith, Terry W.; Walsh, James K.; Kushida, Clete A.

    2013-01-01

    Study Objective: To determine the impact of continuous positive airway pressure (CPAP) on weight change in persons with obstructive sleep apnea (OSA). Design, Setting, and Participants: The Apnea Positive Pressure Long-term Efficacy Study (APPLES) was a 6-month, randomized, double-blinded sham-controlled multicenter clinical trial conducted at 5 sites in the United States. Of 1,105 participants with an apnea hypopnea index ≥ 10 events/ hour initially randomized, 812 had body weight measured at baseline and after 6 months of study. Intervention: CPAP or Sham CPAP. Measurements: Body weight, height, hours of CPAP or Sham CPAP use, Epworth Sleepiness Scale score. Results: Participants randomized to CPAP gained 0.35 ± 5.01 kg, whereas those on Sham CPAP lost 0.70 ± 4.03 kg (mean ± SD, p = 0.001). Amount of weight gain with CPAP was related to hours of device adherence, with each hour per night of use predicting a 0.42 kg increase in weight. This association was not noted in the Sham CPAP group. CPAP participants who used their device ≥ 4 h per night on ≥ 70% of nights gained the most weight over 6 months in comparison to non-adherent CPAP participants (1.0 ± 5.3 vs. -0.3 ± 5.0 kg, p = 0.014). Conclusions: OSA patients using CPAP may gain a modest amount of weight with the greatest weight gain found in those most compliant with CPAP. Commentary: A commentary on this article appears in this issue on page 995. Citation: Quan SF; Budhiraja R; Clarke DP; Goodwin JL; Gottlieb DJ; Nichols DA; Simon RD; Smith TW; Walsh JK; Kushida CA. Impact of treatment with continuous positive airway pressure (CPAP) on weight in obstructive sleep apnea. J Clin Sleep Med 2013;9(10):989-993. PMID:24127141

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

    PubMed

    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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

    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

  3. Standardized weaning of infants <32 weeks of gestation from continuous positive airway pressure - a feasibility study.

    PubMed

    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

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

    PubMed

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

    2016-01-01

    Premature neonates delivered <32 completed weeks gestation are unprepared to handle the physiologic demands of extrauterine life. Within the respiratory system, 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

  5. Continuous Positive Airway Pressure Compliance in Patients with Obstructive Sleep Apnea

    PubMed Central

    Afsharpaiman, Shahla; Vahedi, Encieh; Aqaee, Hossein

    2016-01-01

    Background: Obstructive sleep apnea (OSA) is a common condition in adults. In most cases, first-line therapy includes treatment with positive airway pressure devices. However, because of discomfort, continuous positive airway pressure (CPAP) compliance is often poor. To determine the willingness of patients to use CPAP device, the relationship of demographic and polysomnographic variables with tolerance and the willingness to use CPAP, was evaluated. Materials and Methods: In this cross-sectional study, 120 OSA patients who were treated with CPAP in Baqiyatallah Hospital, Tehran, Iran, were selected by convenience sampling. Polysomnographic variables, willingness to use CPAP for short and long periods of time and possible complications were evaluated. Results: One hundred-twenty cases with a mean age of 53±10.3 years were assessed. The mean Epworth Sleepiness Scale (ESS) score was 11.9 ± 6.2 in CPAP users versus 11.8±6.1 in patients who did not use CPAP. The willingness to use CPAP for short-term was significantly different between the two groups (P=0.008). The average minimum oxygen saturation rate of patients was 75.21% in CPAP users versus 71.63% in non CPAP users. Also, the average desaturation index was higher in CPAP users (54.5 vs. 44.98). The mean ESS was 14.03 ± 6.19 in those who accepted long-term treatment versus 8.85 ± 4.89 (P=0.003). Skin wounds and rhinitis were reported in 4.1% and 4.1% of patients, respectively. Conclusion: It is concluded that high CPAP compliance rates are achievable through comprehensive CPAP therapy.

  6. Does smooth muscle in an intact airway undergo length adaptation during a sustained change in transmural pressure?

    PubMed

    Ansell, Thomas K; McFawn, Peter K; McLaughlin, Robert A; Sampson, David D; Eastwood, Peter R; Hillman, David R; Mitchell, Howard W; Noble, Peter B

    2015-03-01

    In isolated airway smooth muscle (ASM) strips, an increase or decrease in ASM length away from its current optimum length causes an immediate reduction in force production followed by a gradual time-dependent recovery in force, a phenomenon termed length adaptation. In situ, length adaptation may be initiated by a change in transmural pressure (Ptm), which is a primary physiological determinant of ASM length. The present study sought to determine the effect of sustained changes in Ptm and therefore, ASM perimeter, on airway function. We measured contractile responses in whole porcine bronchial segments in vitro before and after a sustained inflation from a baseline Ptm of 5 cmH2O to 25 cmH2O, or deflation to -5 cmH2O, for ∼50 min in each case. In one group of airways, lumen narrowing and stiffening in response to electrical field stimulation (EFS) were assessed from volume and pressure signals using a servo-controlled syringe pump with pressure feedback. In a second group of airways, lumen narrowing and the perimeter of the ASM in situ were determined by anatomical optical coherence tomography. In a third group of airways, active tension was determined under isovolumic conditions. Both inflation and deflation reduced the contractile response to EFS. Sustained Ptm change resulted in a further decrease in contractile response, which returned to baseline levels upon return to the baseline Ptm. These findings reaffirm the importance of Ptm in regulating airway narrowing. However, they do not support a role for ASM length adaptation in situ under physiological levels of ASM lengthening and shortening. PMID:25729015

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

    PubMed Central

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

    2016-01-01

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

  8. Use of a home positive airway pressure device during intraoperative monitored anesthesia care for outpatient surgery.

    PubMed

    Borg, Lindsay; Walters, Tessa L; Siegel, Lawrence C; Dazols, John; Mariano, Edward R

    2016-08-01

    Perioperative positive airway pressure (PAP) is recommended by the American Society of Anesthesiologists for patients with obstructive sleep apnea, but a readily available and personalized intraoperative delivery system does not exist. We present the successful use of a patient's own nasal PAP machine in the operating room during outpatient foot surgery which required addition of a straight adaptor for oxygen delivery and careful positioning of the gas sampling line to permit end-tidal carbox dioxide monitoring. Home PAP machines may provide a potential alternative to more invasive methods of airway management for patients with obstructive sleep apnea under moderate sedation. PMID:27169990

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

    PubMed

    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

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

    PubMed

    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 <1.7 cm H₂O for all ratios; and <10 cm H₂O with mouth closed for ratios <0.9. For ratios >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

  11. Quantifying the Amount of Bleeding and Associated Changes in Intra-Abdominal Pressure and Mean Airway Pressure in Patients Undergoing Lumbar Fixation Surgeries: A Comparison of Three Positioning Systems

    PubMed Central

    Gupta, Vikas; Abraham, Mary; Punetha, Pankaj; Bundela, Yashpal

    2016-01-01

    Study Design Prospective, randomised controlled, single centre study of 45 patients posted for two level lumbar fixation surgery in the prone position. Purpose To compare intra-abdominal pressure (IAP), mean airway pressure mean airway pressure and blood loss during the spine surgery in prone position using three different positioning systems. Overview of Literature Studies have correlated IAP with the amount of perioperative bleeding. However, IAP and airway pressures while assessing the bleeding comparing two or more prone positioning systems are unclear. Methods This prospective study was conducted on a cohort of 45 patients scheduled for two-level lumbar fixation. Patients were randomly allocated to a spine table, Wilson's frame, and thermomodulated pads. Bladder pressure as an indicator of IAP, mean and peak airway pressures, and blood loss were monitored. Results IAP increased whenever patient position was changed to prone .The increase in pressure was more in the Wilson's frame group but was statistically significant only on prolonged positioning. Adopting the prone position always increased the mean airway pressure, but the increased was significant only in the Wilson's frame group. Mean airway pressure decreased in the spine table group and was statistically significant. The blood loss in the spine table group was significantly less as compared to the other groups. Conclusions Positioning on a spine table results in less blood loss and low mean airway pressure. The Wilson's frame results in high IAP, increased mean airway pressure, and more blood loss. The thermomodulated frame increases mean airway pressure and produces a moderate increase in IAP and airway pressure. PMID:27114757

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

    PubMed

    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

  13. Paradoxical responses to positive end-expiratory pressure in patients with airway obstruction during controlled ventilation*

    PubMed Central

    Caramez, Maria Paula; Borges, Joao B.; Tucci, Mauro R.; Okamoto, Valdelis N.; Carvalho, Carlos R. R.; Kacmarek, Robert M.; Malhotra, Atul; Velasco, Irineu Tadeu; Amato, Marcelo B. P.

    2008-01-01

    Objective To reevaluate the clinical impact of external positive end-expiratory pressure (external-PEEP) application in patients with severe airway obstruction during controlled mechanical ventilation. The controversial occurrence of a paradoxic lung deflation promoted by PEEP was scrutinized. Design External-PEEP was applied stepwise (2 cm H2O, 5-min steps) from zero-PEEP to 150% of intrinsic-PEEP in patients already submitted to ventilatory settings minimizing overinflation. Two commonly used frequencies during permissive hypercapnia (6 and 9/min), combined with two different tidal volumes (VT: 6 and 9 mL/kg), were tested. Setting A hospital intensive care unit. Patients Eight patients were enrolled after confirmation of an obstructive lung disease (inspiratory resistance, >20 cm H2O/L per sec) and the presence of intrinsic-PEEP (≥5 cm H2O) despite the use of very low minute ventilation. Interventions All patients were continuously monitored for intra-arterial blood gas values, cardiac output, lung mechanics, and lung volume with plethysmography. Measurements and Main Results Three different responses to external-PEEP were observed, which were independent of ventilatory settings. In the biphasic response, isovolume-expiratory flows and lung volumes remained constant during progressive PEEP steps until a threshold, beyond which overinflation ensued. In the classic overinflation response, any increment of external-PEEP caused a decrease in isovolume-expiratory flows, with evident overinflation. In the paradoxic response, a drop in functional residual capacity during external-PEEP application (when compared to zero-external-PEEP) was commonly accompanied by decreased plateau pressures and total-PEEP, with increased isovolume-expiratory flows. The paradoxic response was observed in five of the eight patients (three with asthma and two with chronic obstructive pulmonary disease) during at least one ventilator pattern. Conclusions External-PEEP application may

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

    PubMed Central

    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

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

    PubMed Central

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

    2015-01-01

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

  16. A systematic review of continuous positive airway pressure for obstructive sleep apnoea-hypopnoea syndrome.

    PubMed

    McDaid, Catriona; Durée, Kate H; Griffin, Susan C; Weatherly, Helen L A; Stradling, John R; Davies, Robert J O; Sculpher, Mark J; Westwood, Marie E

    2009-12-01

    We conducted a systematic review of current evidence on the effectiveness of continuous positive airway pressure (CPAP) for treatment of obstructive sleep apnoea-hypopnoea syndrome (OSAHS). The primary outcomes were subjective sleepiness, using Epworth Sleepiness Scale (ESS) and objective sleepiness using Maintenance of Wakefulness Test (MWT) and Multiple Sleep Latency Test (MSLT). Mean difference (MD) in endpoints was used to compare CPAP to usual care, placebo and dental devices. The analysis was stratified by symptom and disease severity at baseline. CPAP significantly reduced ESS score compared to control (MD -2.7, 95% CI -3.45, -1.96). The benefit was greatest in patients whose symptoms were severe at baseline: severely symptomatic population (MD -5.0, -6.5, -3.5); moderate (MD -2.3, -3.0, -1.6); mild (MD -1.1, -1.8, -0.3). CPAP significantly improved MWT score compared to control (MD 3.3, 1.3, 5.3) but not on the MSLT. There was no statistically significant difference between CPAP and dental devices on the ESS, MWT or MSLT, in a population with moderate symptoms. There was some evidence of benefit for blood pressure with CPAP compared to control. CPAP is an effective treatment for OSAHS in moderate to severe symptomatic patients and there may be benefits for mild symptoms. Dental devices may be a treatment option for moderate symptoms. PMID:19362029

  17. Accuracy and Linearity of Positive Airway Pressure Devices: A Technical Bench Testing Study

    PubMed Central

    Torre-Bouscoulet, Luis; López-Escárcega, Elodia; Carrillo-Alduenda, José Luis; Arredondo-del-Bosque, Fernando; Reyes-Zúñiga, Margarita; Castorena-Maldonado, Armando

    2010-01-01

    Study Objectives: To analyze the accuracy and linearity of different CPAP devices outside of the manufacturers' own quality control environment. Methods: Accuracy (how well readings agree with the gold standard) and linearity were evaluated by comparing programmed pressure to measured CPAP pressure using an instrument established as the gold standard. Comparisons were made centimeter-by-centimeter (linearity) throughout the entire programming spectrum of each device (from 4 to 20 cm H2O). Results: A total of 108 CPAP devices were tested (1836 measurements); mean use of the devices was 956 hours. Twenty-two of them were new. The intra-class correlation coefficient (ICC) decreased from 0.97 at pressures programmed between 4 and 10 cm H2O, to 0.84 at pressures of 16 to 20 cm H2O. Despite this high ICC, the 95% agreement limit oscillated between −1 and 1 cm H2O. This same behavior was observed in relation to hours of use: the ICC for readings taken on devices with < 2,000 hours of use was 0.99, while that of the 50 measurements made on devices with > 6,000 hours was 0.97 (the agreement limit oscillated between −1.3 and 2.5 cm H2O). “Adequate adjustments” were documented in 97% of measurements when the definition was ± 1 cm H2O of the programmed pressure, but this index of adequate adjustment readings decreased to 85% when the ± 0.5 cm H2O criterion was applied. Conclusions: In general, the CPAP devices were accurate and linear throughout the spectrum of programmable pressures; however, strategies to assure short- and long-term equipment reliability are required in conditions of routine use. Citation: Torre-Bouscoulet L; López-Escárcega E; Carrillo-Alduenda JL; Arredondo-del-Bosque F; Reyes-Zúñiga M; Castorena-Maldonado A. Accuracy and linearity of positive airway pressure devices: a technical bench testing study. J Clin Sleep Med 2010;6(4):369-373. PMID:20726286

  18. Effectiveness of applying continuous positive airway pressure in a patient with paradoxical vocal fold movement after endotracheal extubation: a case report.

    PubMed

    Shin, Yeun Hee; Song, Keu La Me; Ko, Dong Chan; Pin, Jung Woo; Ryu, Kyong Ho; Kim, Hyun Soo

    2016-02-01

    Paradoxical vocal fold movement (PVFM) is an uncommon upper airway disorder defined as paradoxical adduction of the vocal folds during inspiration. The etiology and treatment of PVFM are unclear. The physician should manage this condition because of the possibility of near complete airway obstruction in severe case of PVFM. We report a case of successful airway management in a patient with PVFM by applying continuous positive airway pressure (CPAP). In this case, PVFM was detected after removing an endotracheal tube from a 67-year-old male who underwent excision of a laryngeal mass. The patient recovered without complications in 1 day with support by CPAP. PMID:26885309

  19. Effectiveness of applying continuous positive airway pressure in a patient with paradoxical vocal fold movement after endotracheal extubation: a case report

    PubMed Central

    Song, Keu La Me; Ko, Dong Chan; Pin, Jung Woo; Ryu, Kyong Ho; Kim, Hyun Soo

    2016-01-01

    Paradoxical vocal fold movement (PVFM) is an uncommon upper airway disorder defined as paradoxical adduction of the vocal folds during inspiration. The etiology and treatment of PVFM are unclear. The physician should manage this condition because of the possibility of near complete airway obstruction in severe case of PVFM. We report a case of successful airway management in a patient with PVFM by applying continuous positive airway pressure (CPAP). In this case, PVFM was detected after removing an endotracheal tube from a 67-year-old male who underwent excision of a laryngeal mass. The patient recovered without complications in 1 day with support by CPAP. PMID:26885309

  20. Dynamic airway pressure-time curve profile (Stress Index): a systematic review.

    PubMed

    Terragni, Pierpaolo; Bussone, Guido; Mascia, Luciana

    2016-01-01

    The assessment of respiratory mechanics at the bedside is necessary in order to identify the most protective ventilatory strategy. Indeed in the last 20 years, adverse effects of positive ventilation to the lung structures have led to a reappraisal of the objectives of mechanical ventilation. The ventilator setting requires repeated readjustment over the period of mechanical ventilation dependency and careful respiratory monitoring to minimize the risks, preventing further injury and permitting the lung and airways healing. Among the different methods that have been proposed and validated, the analysis of dynamic P-t curve (named Stress Index, SI) represents an adequate tool available at the bedside, repeatable and, therefore, able to identify the amount of overdistension occurring in the daily clinical practice, when modifying positive end-expiratory pressure. In this review we will analyze the evidence that supports respiratory mechanics assessment at the bedside and the application of the dynamic P/t curve profile (SI) to optimize protective ventilation in patients with acute respiratory failure. PMID:25786405

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

    PubMed Central

    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. PMID:27445563

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

    PubMed Central

    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 hours after surgery following fulfilling of acute respiratory failure criterias whereas, in Group 2, BIPAP was applied one hour after extubation for two episodes of 20 minute duration and 3 hours apart. Arterial blood gas values (pH, PaO2, PaCO2) at first and fourth hour after BIPAP were collected. Results: In comparison between groups, no significant differences were observed for arterial blood gas values of pH and PaCO2 at baseline, one and four hours after BIPAP (p > 0.05) however, the PaO2 values at one and four hours after BIPAP were significantly better in Group 1 in comparison to Group 2 (p < 0.001, p < 0.001; respectively). Reintubation rate was 14 patients (11%) in Group 1 and 7 patients (5.5%) in Group 2 (p = 0.103). Conclusıons: The early and prophylactic use of BIPAP after cardiac or thoracic operations did not provide diminished rates in the postoperative complications such as reintubation. PMID:25419380

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

    PubMed Central

    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 insight to measuring adherence outcomes, defining optimal adherence levels, and predicting CPAP adherence. This research has revealed salient factors that are associated with or predict CPAP adherence and may guide the development of interventions to promote CPAP adherence. Over the past 10 years, intervention studies to promote CPAP adherence have incorporated a multitude of strategies including education, support, cognitive behavioral approaches, and mixed strategies. This review of the current state of science of CPAP adherence will (1) synthesize the extant literature with regard to measuring, defining, and predicting CPAP adherence, (2) review published intervention studies aimed at promoting CPAP adherence, and (3) suggest directions for future empiric study of adherence to CPAP that will have implications for translational science. Our current understanding of CPAP adherence suggests that adherence is a multi-factorial, complex clinical problem that requires similarly designed approaches to effectively address poor CPAP adherence in the OSA population. PMID:20308750

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

    PubMed

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

    2016-04-01

    Positive airway pressure (PAP) treatment has been shown to have a modest effect on ambulatory blood pressure (BP) in patients with obstructive sleep apnea (OSA). However, there is a paucity of data on the effect of PAP therapy on rapid, yet significant, BP swings during sleep, particularly in obesity hypoventilation syndrome (OHS). The present study hypothesizes that PAP therapy will improve nocturnal BP on the first treatment night (titration PAP) in OHS patients with underlying OSA, and that these improvements will become more significant with 6 wk of PAP therapy. Seventeen adults (7 men, 10 women; age 50.4 ± 10.7 years, BMI 49.3 ± 2.4 kg/m(2)) with OHS and clinically diagnosed OSA participated in three overnight laboratory visits that included polysomnography and beat-to-beat BP monitoring via finger plethysmography. Six weeks of PAP therapy, but not titration PAP, lowered mean nocturnal BP. In contrast, when nocturnal beat-to-beat BPs were aggregated into bins consisting of at least three consecutive cardiac cycles with a >10 mmHg BP surge (i.e., Δ10-20, Δ20-30, Δ30-40, and Δ>40 mmHg), titration, and 6-wk PAP reduced the number of BP surges per hour (time × bin,P< 0.05). PAP adherence over the 6-wk period was significantly correlated to reductions in nocturnal systolic (r= 0.713,P= 0.001) and diastolic (r= 0.497,P= 0.043) BP surges. Despite these PAP-induced improvements in nocturnal beat-to-beat BP surges, 6 wk of PAP therapy did not alter daytime BP. In conclusion, PAP treatment reduces nocturnal beat-to-beat BP surges in OHS patients with underlying OSA, and this improvement in nocturnal BP regulation was greater in patients with higher PAP adherence. PMID:26818059

  5. Analysis of heart rate variability in individuals subjected to different positive end expiratory pressure levels using expiratory positive airway pressure

    PubMed Central

    Pinto, Thiago Lorentz; Costa, Ivan Peres; Kawaguchi, Leandro Yukio Alves; de Carvalho, Flávio Aimbire Soares; de Carvalho, Regiane Albertini

    2013-01-01

    Introduction The increase in the number of studies has led to greater security in the application of this method and the determination of its effectiveness in adults.. The purpose of the present study was to evaluate heart rate variability in healthy individuals submitted to different levels of positive expiratory pressure using an expiratory positive airway pressure (EPAP) device. Material and methods The study involved 27 healthy male individuals ranging in age from 20 to 35 years. Patient histories were taken and the subjects were submitted to a physical examination. The volunteers were monitored using the Polar 810s® and submitted to the EPAP experiment. Analyses were performed on variables of the frequency domain. Sympathetic and parasympathetic bands and their relationship with sympathovagal response were also analyzed. Results The mean value of this variable was 526.89 (55.50) ms2 in the first period, 2811.0 (721.10) ms2 in the fourth period and 726.52 (123.41) ms2 in the fifth period. Regarding the parasympathetic area, significant differences were detected when Periods 1 and 5 (no load) were compared with periods in which the individuals were subjected to the use of the therapy. Sympathetic and parasympathetic areas together, a significant difference was detected regarding the sympathetic/parasympathetic ratio in the comparison between Periods 1 and 4 (p < 0.01) as well as Periods 2 and 4 (p < 0.05). Conclusions The findings of the present study suggest that the therapeutic use of EPAP significantly alters the parameters of heart rate variability in the frequency domain, highlighting the importance of monitoring and care during the practice of EPAP. PMID:24049524

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

    PubMed

    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

  7. High Flow Nasal Cannula as a Method for Rapid Weaning From Nasal Continuous Positive Airway Pressure

    PubMed Central

    Badiee, Zohreh; Eshghi, Alireza; Mohammadizadeh, Majid

    2015-01-01

    Background: To compare two methods of weaning premature infants from nasal continuous positive airway pressure (NCPAP). Methods: Between March and November 2012, 88 preterm infants who were stable on NCPAP of 5 cmH2O with FIO2 <30% for a minimum of 6 h were randomly allocated to one of two groups. The high flow nasal cannula (HFNC) group received HFNC with flow of 2 L/min and FIO2 = 0.3 and then stepwise reduction of FIO2 and then flow. The non-HFNC group was maintained on NCPAP of 5 cmH2O and gradual reduction of oxygen until they were on FIO2 = 0.21 for 6 h, and we had weaned them directly from NCPAP (with pressure of 5 cmH2O) to room air. Results: No significant differences were found between 2 study groups with regards to gestational age, birth weight, Apgar score at 1 and 5 min after birth, patent ductus arteriosus and use of xanthines. The mean duration of oxygen therapy after randomization was significantly lower in HFNC group compared to non-HFNC group (20.6 ± 16.8 h vs. 49.6 ± 25.3 h, P < 0.001). Also, the mean length of hospital stay was significantly lower in HFNC group compared to non-HFNC group (11.3 ± 7.8 days vs. 14.8 ± 8.6 days, P = 0.04). The rate of successful weaning was not statistically different between two groups. Conclusions: Weaning from NCPAP to HFNC could decrease the duration of oxygen therapy and length of hospitalization in preterm infants. PMID:25949783

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

    PubMed Central

    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

  9. Cosmic Pressure Fronts Mapped by Chandra

    NASA Astrophysics Data System (ADS)

    2000-03-01

    A colossal cosmic "weather system" produced by the collision of two giant clusters of galaxies has been imaged by NASA's Chandra X-ray Observatory. For the first time, the pressure fronts in the system can be traced in detail, and they show a bright, but relatively cool 50 million degree Celsius central region embedded in large elongated cloud of 70 million degree Celsius gas, all of which is roiling in a faint "atmosphere"of 100 million degree Celsius gas. "We can compare this to an intergalactic cold front," said Maxim Markevitch of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. and leader of the international team involved in the analysis of the observations. "A major difference is that in this case, cold means 70 million degree Celsius." The gas clouds are in the core of a galaxy cluster known as Abell 2142. The cluster is six million light years across and contains hundreds of galaxies and enough gas to make a thousand more. It is one of the most massive objects in the universe. Galaxy clusters grow to vast sizes as smaller clusters are pulled inward under the influence of gravity. They collide and merge over the course of billions of years, releasing tremendous amounts of energy that heats the cluster gas to 100 million degrees Celsius. The Chandra data provides the first detailed look at the late stages of this merger process. Previously, scientists had used the German-US Roentgensatellite to produce a broad brush picture of the cluster. The elongated shape of the bright cloud suggested that two clouds were in the process of coalescing into one, but the details remained unclear. Chandra is able to measure variations of temperature, density, and pressure with unprecedented resolution. "Now we can begin to understand the physics of these mergers, which are among the most energetic events in the universe," said Markevitch. "The pressure and density maps of the cluster show a sharp boundary that can only exist in the moving environment of a

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

    PubMed Central

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

    2016-01-01

    Background: Stress index at post-recruitment maneuvers could be a method of positive end-expiratory pressure (PEEP) titration in acute respiratory distress syndrome (ARDS) patients. However, airway pressure (Paw) stress index may not reflect lung mechanics in the patients with high chest wall elastance. This study was to evaluate the Paw stress index on lung mechanics and the correlation between Paw stress index and transpulmonary pressure (PL) stress index in acute respiratory failure (ARF) patients. Methods: Twenty-four ARF patients with mechanical ventilation (MV) were consecutively recruited from July 2011 to April 2013 in Zhongda Hospital, Nanjing, China and Ospedale S. Giovanni Battista-Molinette Hospital, Turin, Italy. All patients underwent MV with volume control (tidal volume 6 ml/kg) for 20 min. PEEP was set according to the ARDSnet study protocol. The patients were divided into two groups according to the chest wall elastance/respiratory system elastance ratio. The high elastance group (H group, n = 14) had a ratio ≥30%, and the low elastance group (L group, n = 10) had a ratio <30%. Respiratory elastance, gas-exchange, Paw stress index, and PL stress index were measured. Student's t-test, regression analysis, and Bland–Altman analysis were used for statistical analysis. Results: Pneumonia was the major cause of respiratory failure (71.0%). Compared with the L group, PEEP was lower in the H group (5.7 ± 1.7 cmH2O vs. 9.0 ± 2.3 cmH2O, P < 0.01). Compared with the H group, lung elastance was higher (20.0 ± 7.8 cmH2O/L vs. 11.6 ± 3.6 cmH2O/L, P < 0.01), and stress was higher in the L group (7.0 ± 1.9 vs. 4.9 ± 1.9, P = 0.02). A linear relationship was observed between the Paw stress index and the PL stress index in H group (R2= 0.56, P < 0.01) and L group (R2= 0.85, P < 0.01). Conclusion: In the ARF patients with MV, Paw stress index can substitute for PL to guide ventilator settings. Trial Registration: ClinicalTrials.gov NCT02196870 (https

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

    PubMed

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

    2016-04-01

    Compliance of soft tissue and muscle supporting the upper airway are two of several factors contributing to pharyngeal airway collapse. We present a novel, minimally invasive method of estimating regional variations in pharyngeal elasticity. Magnetic resonance images for pediatric sleep apnea patients with Down syndrome [9.5 ± 4.3 years (mean age ± standard deviation)] were analyzed to segment airways corresponding to baseline (no mask pressure) and two positive pressures. A three dimensional map was created to evaluate axial and circumferential variation in radial displacements of the airway, dilated by the positive pressures. The displacements were then normalized with respect to the appropriate transmural pressure and radius of an equivalent circle to obtain a measure of airway compliance. The resulting elasticity maps indicated the least and most compliant regions of the pharynx. Airway stiffness of the most compliant region [403 ± 204 (mean ± standard deviation) Pa] decreased with severity of obstructive sleep apnea. The non-linear response of the airway wall to continuous positive airway pressure was patient specific and varied between anatomical locations. We identified two distinct elasticity phenotypes. Patient phenotyping based on airway elasticity can potentially assist clinical practitioners in decision making on the treatments needed to improve airway patency. PMID:26215306

  12. Established vascular effects of continuous positive airway pressure therapy in patients with obstructive sleep apnoea—an update

    PubMed Central

    Wons, Annette Marie

    2015-01-01

    The aim of this review was to summarize the current data from randomised controlled trials (RCTs) on vascular effects of continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnoea (OSA). There is good evidence from RCTs that CPAP lowers blood pressure (BP) to a clinically significant amount. The effect seems to be dependent on the hours of nightly CPAP usage. Data from RCTs have also proven a beneficial effect of CPAP on measures of vascular function such as endothelial function and arterial stiffness. However, there is still a lack of evidence from RCTs proving that CPAP reduces vascular events and mortality. PMID:26101649

  13. A survey of airway responsiveness in 36 inbred mouse strains facilitates gene mapping studies and identification of quantitative trait loci

    PubMed Central

    Leme, Adriana S.; Williams, Laura K.; Tsaih, Shirng-Wern; Szatkiewicz, Jin P.; Verdugo, Ricardo; Paigen, Beverly; Shapiro, Steven D.

    2010-01-01

    Airway hyper-responsiveness (AHR) is a critical phenotype of human asthma and animal models of asthma. Other studies have measured AHR in nine mouse strains, but only six strains have been used to identify genetic loci underlying AHR. Our goals were to increase the genetic diversity of available strains by surveying 27 additional strains, to apply haplotype association mapping to the 36-strain survey, and to identify new genetic determinants for AHR. We derived AHR from the increase in airway resistance in females subjected to increasing levels of methacholine concentrations. We used haplotype association mapping to identify associations between AHR and haplotypes on chromosomes 3, 5, 8, 12, 13, and 14. And we used bioinformatics techniques to narrow the identified region on chromosome 13, reducing the region to 29 candidate genes, with 11 of considerable interest. Our combined use of haplotype association mapping with bioinformatics tools is the first study of its kind for AHR on these 36 strains of mice. Our analyses have narrowed the possible QTL genes and will facilitate the discovery of novel genes that regulate AHR in mice. PMID:20143096

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

    PubMed Central

    Gonçalves-Ferri, W.A.; Martinez, F.E.; Caldas, J.P.S.; Marba, S.T.M.; Fekete, S.; Rugolo, L.; Tanuri, C.; Leone, C.; Sancho, G.A.; Almeida, M.F.B.; Guinsburg, R.

    2014-01-01

    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. PMID:24554040

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

    PubMed Central

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

    2015-01-01

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

  16. Reversibility of albuminuria and continuous positive airway pressure compliance in patients of obstructive sleep apnea syndrome.

    PubMed

    Chen, Ning-Hung; Chou, Yu-Ting; Lee, Pei-Hsien; Lin, Shih-Wei; Chuang, Li-Pang; Lin, Yu-Sheng; Yang, Cheng-Ta

    2016-06-01

    A positive correlation between albuminuria and severity of obstructive sleep apnea syndrome (OSAS) has been demonstrated, as indexed by urine albumin-to-creatinine ratios (UACRs). However, the effect of continuous positive airway pressure (CPAP) treatment on albuminuria in OSAS patients has not been established.Sixty subjects, with apnea-hypopnea indices >15 events per hour and no other diagnoses associated with albuminuria, underwent overnight polysomnography for sleep apnea and were examined for UACR at baseline and after 6 months of CPAP therapy. CPAP compliance rates were also recorded.Significant improvement in UACR was found in OSAS patients with good compliance to CPAP treatment after 6 months of therapy (baseline vs 6-month follow-up, 32.0 ± 9.5 vs 19.2 ± 6.5 mg/g, respectively, P = 0.007), whereas slight worsening in UACRs was noted in patients with poor compliance to CPAP treatment (baseline vs 6-month follow-up, respectively, 16.7 ± 4.4 vs 19.1 ± 6.3 mg/g, respectively, P = 0.39). Change in UACR was significant between poor compliance versus good compliance groups (2.4 ± 2.7 vs -12.8 ± 4.4 mg/g, respectively, t = 2.9, P = 0.005). A significant correlation between improvement in UACR and CPAP compliance rates was also noted (Spearman's correlation coefficient: -0.37, P = 0.007). Baseline UACR, good CPAP compliance, and body mass index were independent predictors of changes in UACR.Adequate CPAP treatment improves albuminuria in OSAS patients. In addition to monitoring CPAP adherence and subjective sleepiness, UACR may offer an objective physiological index of CPAP therapeutic effectiveness. PMID:27368036

  17. Reversibility of albuminuria and continuous positive airway pressure compliance in patients of obstructive sleep apnea syndrome

    PubMed Central

    Chen, Ning-Hung; Chou, Yu-Ting; Lee, Pei-Hsien; Lin, Shih-Wei; Chuang, Li-Pang; Lin, Yu-Sheng; Yang, Cheng-Ta

    2016-01-01

    Abstract A positive correlation between albuminuria and severity of obstructive sleep apnea syndrome (OSAS) has been demonstrated, as indexed by urine albumin-to-creatinine ratios (UACRs). However, the effect of continuous positive airway pressure (CPAP) treatment on albuminuria in OSAS patients has not been established. Sixty subjects, with apnea-hypopnea indices >15 events per hour and no other diagnoses associated with albuminuria, underwent overnight polysomnography for sleep apnea and were examined for UACR at baseline and after 6 months of CPAP therapy. CPAP compliance rates were also recorded. Significant improvement in UACR was found in OSAS patients with good compliance to CPAP treatment after 6 months of therapy (baseline vs 6-month follow-up, 32.0 ± 9.5 vs 19.2 ± 6.5 mg/g, respectively, P = 0.007), whereas slight worsening in UACRs was noted in patients with poor compliance to CPAP treatment (baseline vs 6-month follow-up, respectively, 16.7 ± 4.4 vs 19.1 ± 6.3 mg/g, respectively, P = 0.39). Change in UACR was significant between poor compliance versus good compliance groups (2.4 ± 2.7 vs −12.8 ± 4.4 mg/g, respectively, t = 2.9, P = 0.005). A significant correlation between improvement in UACR and CPAP compliance rates was also noted (Spearman's correlation coefficient: −0.37, P = 0.007). Baseline UACR, good CPAP compliance, and body mass index were independent predictors of changes in UACR. Adequate CPAP treatment improves albuminuria in OSAS patients. In addition to monitoring CPAP adherence and subjective sleepiness, UACR may offer an objective physiological index of CPAP therapeutic effectiveness. PMID:27368036

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

    PubMed

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

    2015-01-01

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

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

    PubMed

    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

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

    PubMed Central

    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 < 0.001) and after sleep (19.0 ± 7.7 ppb vs. 6.9 ± 3.7; p < 0.001). Furthermore, in patients with OSA, FENO levels were significantly higher post-sleep than pre-sleep (19.0 ± 7.7 ppb vs. 13.4 ± 6.5; p < 0.001), while there was no significant overnight change in patients without OSA. The rise in FENO correlated with the apnea-hypopnea index (r = 0.65, p < 0.001), nadir oxygen saturation (r = 0.54, p < 0.001), and arousal index (r = 0.52, p < 0.001). Thirty-seven of these patients underwent CPAP titration and treatment. Successful titration was associated with a lower overnight increase in FENO (7.2 ± 3.3 vs. 11.0 ± 4.3, p = 0.02). FENO levels declined after 1-3 months of CPAP therapy (11.7 ± 4.4 ppb, p < 0.001). Conclusions: FENO levels are elevated in OSA, correlate with severity, and decrease after positive pressure therapy. This study supports the role of upper airway inflammation in OSA pathogenesis and a possible role for FENO in monitoring CPAP therapy. Citation: Chua AP; Aboussouan LS; Minai OA; 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

  1. Bi-level positive airway pressure (BiPAP) and acute cardiogenic pulmonary oedema (ACPO) in the emergency department.

    PubMed

    Murray, Sarah

    2002-05-01

    Patients in acute respiratory failure (ARF) frequently present to the emergency department (ED). Traditionally management has involved mechanical ventilation via endotracheal intubation. Such invasive forms of treatment, however, correlate with a higher incidence of infection, mortality, length of stay and contribute to the costs of intensive care. Non-invasive positive pressure ventilation (NIPPV) such as bi-level positive airway pressure (BiPAP) may therefore provide an alternative and preferable form of treatment. Whilst contemporary literature supports the use of BiPAP in hypercapnic ARF, its role in acute hypoxaemic presentations remains elusive. Specifically, the efficacy and safety of BiPAP in the treatment of acute cardiogenic pulmonary oedema (ACPO) remains a contentious issue. The aim of this paper is to explore the physiological rationale for treatment of ACPO with BiPAP. Particular attention will focus on the comparative theoretical advantages of BiPAP in relation to continuous positive airway pressure (CPAP), and a review of recent research. Discussion will incorporate timeliness in the application of BiPAP, indicators of successful treatment, appropriate manipulation of pressure settings, nursing workload and management of patients beyond the ED. Whilst the theoretical advantages of BiPAP ventilation are acknowledged, larger randomised controlled research studies are recommended in order to clearly ensure its safe and effective application in the treatment of ACPO. PMID:12154698

  2. Modafinil Increases Awake EEG Activation and Improves Performance in Obstructive Sleep Apnea during Continuous Positive Airway Pressure Withdrawal

    PubMed Central

    Wang, David; Bai, Xiao Xue; Williams, Shaun C.; Hua, Shu Cheng; Kim, Jong-Won; Marshall, Nathaniel S.; D'Rozario, Angela; Grunstein, Ronald R.

    2015-01-01

    Objectives: We examined the changes in waking electroencephalography (EEG) biomarkers with modafinil during continuous positive airway pressure (CPAP) withdrawal in patients with obstructive sleep apnea (OSA) to investigate neurophysiological evidence for potential neurocognitive improvements. Design: Randomized double-blind placebo-controlled crossover study. CPAP was used for the first night and then withdrawn for 2 subsequent nights. Each morning after the 2 CPAP withdrawal nights, patients received either 200 mg modafinil or placebo. After a 5-w washout, the procedure repeated with the crossover drug. Setting: University teaching hospital. Participants: Stable CPAP users (n = 23 men with OSA) Measurement and Results: Karolinska Drowsiness Test (KDT) (awake EEG measurement with eyes open and closed), Psychomotor Vigilance Task (PVT), and driving simulator Performance were assessed bihourly during the 3 testing days following CPAP treatment and CPAP withdrawal nights. Compared to placebo, modafinil significantly increased awake EEG activation (faster EEG frequency) with increased alpha/delta (A/D) ratio (P < 0.0001) and fast ratio = (alpha+beta)/(delta+theta) (P < 0.0001) across the 2 days of CPAP withdrawal. The A/D ratio significantly correlated with the driving simulator response time (P = 0.015), steering variation (P = 0.002), and PVT reaction time (P = 0.006). In contrast, individual EEG band power of alpha, beta, theta, and delta did not correlate with any neurocognitive performance. Conclusions: Modafinil administration during continuous positive airway pressure (CPAP) withdrawal increased awake EEG activation, which correlated to improved performance. This study provides supporting neurophysiological evidence that modafinil is a potential short-term treatment option during acute CPAP withdrawal. Citation: Wang D, Bai XX, Williams SC, Hua SC, Kim JW, Marshall NS, D'Rozario A, Grunstein RR. Modafinil increases awake EEG activation and improves performance

  3. Continuous positive airway pressure for bronchiolitis in a general paediatric ward; a feasibility study

    PubMed Central

    2014-01-01

    Background Continuous positive airway pressure (CPAP) is commonly used to relieve respiratory distress in infants with bronchiolitis, but has mostly been studied in an intensive care setting. Our prime aim was to evaluate the feasibility of CPAP for infants with bronchiolitis in a general paediatric ward, and secondary to assess capillary PCO2 (cPCO2) levels before and during treatment. Methods From May 1st 2008 to April 30th 2012, infants with bronchiolitis at Stavanger University Hospital were treated with CPAP in a general paediatric ward, but could be referred to an intensive care unit (ICU) when needed, according to in-house guidelines. Levels of cPCO2 were prospectively registered before the start of CPAP and at approximately 4, 12, 24 and 48 hours of treatment as long as CPAP was given. We had a continuous updating program for the nurses and physicians caring for the infants with CPAP. The study was population based. Results 672 infants (3.4%) were hospitalized with bronchiolitis. CPAP was initiated in 53 infants (0.3%; 7.9% of infants with bronchiolitis), and was well tolerated in all but three infants. 46 infants were included in the study, the majority of these (n = 33) were treated in the general ward only. These infants had lower cPCO2 before treatment (8.0; 7.7, 8.6)(median; quartiles) than those treated at the ICU (n = 13) (9.3;8.5, 9.9) (p < 0.001). The level of cPCO2 was significantly reduced after 4 h in both groups; 1.1 kPa (paediatric ward) (p < 0.001) and 1.3 kPa (ICU) (p = 0.002). Two infants on the ICU did not respond to CPAP (increasing cPCO2 and severe apnoe) and were given mechanical ventilation, otherwise no side effects were observed in either group treated with CPAP. Conclusion Treatment with CPAP for infants with bronchiolitis may be feasible in a general paediatric ward, providing sufficient staffing and training, and the possibility of referral to an ICU when needed. PMID:24886569

  4. Cost-effectiveness of Out-of-Hospital Continuous Positive Airway Pressure for Acute Respiratory Failure

    PubMed Central

    Thokala, Praveen; Goodacre, Steve; Ward, Matt; Penn-Ashman, Jerry; Perkins, Gavin D.

    2015-01-01

    Study objective We determine the cost-effectiveness of out-of-hospital continuous positive airway pressure (CPAP) compared with standard care for adults presenting to emergency medical services with acute respiratory failure. Methods We developed an economic model using a United Kingdom health care system perspective to compare the costs and health outcomes of out-of-hospital CPAP to standard care (inhospital noninvasive ventilation) when applied to a hypothetical cohort of patients with acute respiratory failure. The model assigned each patient a probability of intubation or death, depending on the patient’s characteristics and whether he or she had out-of-hospital CPAP or standard care. The patients who survived accrued lifetime quality-adjusted life-years (QALYs) and health care costs according to their age and sex. Costs were accrued through intervention and hospital treatment costs, which depended on patient outcomes. All results were converted into US dollars, using the Organisation for Economic Co-operation and Development purchasing power parities rates. Results Out-of-hospital CPAP was more effective than standard care but was also more expensive, with an incremental cost-effectiveness ratio of £20,514 per QALY ($29,720/QALY) and a 49.5% probability of being cost-effective at the £20,000 per QALY ($29,000/QALY) threshold. The probability of out-of-hospital CPAP’s being cost-effective at the £20,000 per QALY ($29,000/QALY) threshold depended on the incidence of eligible patients and varied from 35.4% when a low estimate of incidence was used to 93.8% with a high estimate. Variation in the incidence of eligible patients also had a marked influence on the expected value of sample information for a future randomized trial. Conclusion The cost-effectiveness of out-of-hospital CPAP is uncertain. The incidence of patients eligible for out-of-hospital CPAP appears to be the key determinant of cost-effectiveness. PMID:25737210

  5. Prototype development and comparative evaluation of wheelchair pressure mapping system.

    PubMed

    Ferguson-Pell, M; Cardi, M D

    1993-01-01

    Wheelchair pressure mapping devices used in the prescription of seat cushions and postural supports have been limited in durability, data presentation, and/or clinical efficiency. This project sought to establish the ideal specifications for clinically useful pressure mapping systems, and to use these specifications to influence the design of an innovative wheelchair pressure mapping system (Tekscan "Seat"). Technology, previously developed for measurement of forces of dental occlusion and of the foot during gait, was applied to wheelchair seat mapping. Tests were designed to compare the performance of three pressure mapping systems: the Tekscan system, the FSA system, and the Talley TPM3. Bench tests were done to measure reproducibility, hysteresis, and creep of each of the pressure mapping systems. A contoured loader gauge was developed to test for the influence of hammocking. Tests were also performed using spinal cord-injured subjects to demonstrate the relative performance of the pressure mapping systems in a clinical setting. A focus group session was conducted with seating specialists to review the strengths and weakness of the systems for routine clinical use. The TPM3 was found to be the most accurate, stable, and reproducible but limited in ease of use, speed, and data presentation. FSA was rated well in clinical application and data management but demonstrated a pronounced hysteresis (+/-19%) and creep (4%). The Tekscan system also showed substantial hysteresis (+/-20%) and creep (19%) but was preferred by clinicians for its real-time display capabilities, resolution, and display options. Some trends in system performance on varied support surfaces were identified and can be a valuable guide to interpretation of measurements and prescription decision making in the clinic. Problems identified with the accuracy and stability of the Tekscan and FSA systems may be amenable to resolution with software correction and changes in fabrication. With these

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

    PubMed

    Hevener, Bretton; Hevener, William

    2016-09-01

    Sleep apnea is a form of sleep-disordered breathing that is associated with an increase in disease comorbidities, mortality risks, health care costs, and traffic accidents. Sleep apnea is most commonly treated with positive airway pressure (PAP). PAP can be difficult for patients to tolerate. This leads to initial and long-term noncompliance. Most insurance companies require compliance with PAP treatment to cover ongoing reimbursements for the device and related disposable supplies. Therefore, there are both clinical and financial incentives to a sleep apneic patient's compliance with PAP therapy. PMID:27542878

  7. Three-Dimensional Mapping of Ozone-Induced Injury in the Nasal Airways of Monkeys Using Magnetic Resonance Imaging and Morphometric Techniques

    SciTech Connect

    Carey, Stephen A.; Minard, Kevin R.; Trease, Lynn L.; Wagner, James G.; Garcia, Guilherme M.; Ballinger, Carol A.; Kimbell, Julia; Plopper, Charles G.; Corley, Rick A.; Postlewait, Ed; Harkema, Jack R.

    2007-03-01

    ABSTRACT Age-related changes in gross and microscopic structure of the nasal cavity can alter local tissue susceptibility as well as the dose of inhaled toxicant delivered to susceptible sites. This article describes a novel method for the use of magnetic resonance imaging, 3-dimensional airway modeling, and morphometric techniques to characterize the distribution and magnitude of ozone-induced nasal injury in infant monkeys. Using this method, we are able to generate age-specific, 3-dimensional, epithelial maps of the nasal airways of infant Rhesus macaques. The principal nasal lesions observed in this primate model of ozone-induced nasal toxicology were neutrophilic rhinitis, along with necrosis and exfoliation of the epithelium lining the anterior maxilloturbinate. These lesions, induced by acute or cyclic (episodic) exposures, were examined by light microscopy, quantified by morphometric techniques, and mapped on 3-dimensional models of the nasal airways. Here, we describe the histopathologic, imaging, and computational biology methods developed to efficiently characterize, localize, quantify, and map these nasal lesions. By combining these techniques, the location and severity of the nasal epithelial injury were correlated with epithelial type, nasal airway geometry, and local biochemical and molecular changes on an individual animal basis. These correlations are critical for accurate predictive modeling of exposure-dose-response relationships in the nasal airways, and subsequent extrapolation of nasal findings in animals to humans for developing risk assessment.

  8. Effects of nasal continuous positive airway pressure and oxygen supplementation on norepinephrine kinetics and cardiovascular responses in obstructive sleep apnea.

    PubMed

    Mills, Paul J; Kennedy, Brian P; Loredo, Jose S; Dimsdale, Joel E; Ziegler, Michael G

    2006-01-01

    Obstructive sleep apnea (OSA) is characterized by noradrenergic activation. Nasal continuous positive airway pressure (CPAP) is the treatment of choice and has been shown to effectively reduce elevated norepinephrine (NE) levels. This study examined whether the reduction in NE after CPAP is due to an increase in NE clearance and/or a decrease of NE release rate. Fifty CPAP-naive OSA patients with an apnea-hypopnea index >15 were studied. NE clearance and release rates, circulating NE levels, urinary NE excretion, and blood pressure and heart rate were determined before and after 14 days of CPAP, placebo CPAP (CPAP administered at ineffective pressure), or oxygen supplementation. CPAP led to a significant increase in NE clearance (P < or = 0.01), as well as decreases in plasma NE levels (P < or = 0.018) and daytime (P < 0.001) and nighttime (P < 0.05) NE excretion. NE release rate was unchanged with treatment. Systolic (P < or = 0.013) and diastolic (P < or = 0.026) blood pressure and heart rate (P < or = 0.014) were decreased in response to CPAP but not in response to oxygen or placebo CPAP treatment. Posttreatment systolic blood pressure was best predicted by pretreatment systolic blood pressure and posttreatment NE clearance and release rate (P < 0.01). The findings indicate that one of the mechanisms through which CPAP reduces NE levels is through an increase in the clearance of NE from the circulation. PMID:16357087

  9. Use of volume-targeted non-invasive bilevel positive airway pressure ventilation in a patient with amyotrophic lateral sclerosis*,**

    PubMed Central

    Diaz-Abad, Montserrat; Brown, John Edward

    2014-01-01

    Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease in which most patients die of respiratory failure. Although volume-targeted non-invasive bilevel positive airway pressure (BPAP) ventilation has been studied in patients with chronic respiratory failure of various etiologies, its use in ALS has not been reported. We present the case of a 66-year-old woman with ALS and respiratory failure treated with volume-targeted BPAP ventilation for 15 weeks. Weekly data downloads showed that disease progression was associated with increased respiratory muscle weakness, decreased spontaneous breathing, and increased use of non-invasive positive pressure ventilation, whereas tidal volume and minute ventilation remained relatively constant. PMID:25210968

  10. Increased airway pressure due to superior mediastinal hematoma during endovascular coiling by transcarotid approach.

    PubMed

    Gupta, Priyanka; Rath, Girija Prasad; Banik, Sujoy; Mahajan, Charu

    2016-05-01

    An elderly woman with subarachanoid hemorrhage presented to our interventional neuroradiology suite for coil embolization of multiple intracranial aneurysms. The patient had difficult vascular access for the passage of microcatheter; hence, the embolization procedure was carried out with direct puncture of the left common carotid artery. During the procedure, the patient developed thromboembolism which was treated by administration of an antiplatelet agent, abciximab. At the end of procedure, she developed airway compromise due to extension of a local neck hematoma into the superior mediastinum. The management issues in such a scenario have been discussed. PMID:27041267

  11. Evaluation of carbon dioxide rebreathing during pressure support ventilation with airway management system (BiPAP) devices.

    PubMed

    Lofaso, F; Brochard, L; Touchard, D; Hang, T; Harf, A; Isabey, D

    1995-09-01

    The purpose of this study was to evaluate whether carbon dioxide (CO2) rebreathing occurs in acute respiratory failure patients ventilated using the standard airway management system (BiPAP pressure support ventilator; Respironics; Murrysville, Pa) with positive inspiratory airway pressure and a minimal level of positive end-expiratory pressure (PEEP) and whether any CO2 rebreathing may be efficiently prevented by the addition of a nonrebreathing valve to the BiPAP system circuit. In the first part of the study, the standard device was tested on a lung model with a nonrebreathing valve (BiPAP-NRV) and with the usual Whisper Swivel connector (BiPAP-uc). With the BiPAP-uc device, the resident volume of expired air in the inspiratory circuit at the end of expiration (RVEA) was 55% of the tidal volume (VT) when the inspiratory pressure was 10 cm H2O and the frequency was at 15 cycles per minute. The BiPAP-NRV device efficiently prevented CO2 rebreathing but resulted in a slight decrease in VT, which was due to a significant increase in external PEEP (2.4 vs 1.3 cm H2O) caused by the additional expiratory valve resistance. For similar reasons, both the pressure swing necessary to trigger pressure support and the imposed expiratory work were increased in the lung model when the nonrebreathing valve was used. In the second part of the study, seven patients weaned from mechanical ventilation were investigated using a randomized crossover design to compare three situations: pressure support ventilation with a conventional intensive care ventilator (CIPS), BiPAP system use, and BiPAP-NRV. When we compared the BiPAP system use with the other two systems, we observed no significant effect on blood gases but found significant increases in VT, minute ventilation, and work of breathing. These findings are experimental and are clinical evidence that significant CO2 rebreathing occurs with the standard BiPAP system. This drawback can be overcome by using a non-rebreathing valve

  12. Pilot Study of Nasal Expiratory Positive Airway Pressure Devices for the Treatment of Childhood Obstructive Sleep Apnea Syndrome

    PubMed Central

    Kureshi, Suraiya A.; Gallagher, Paul R.; McDonough, Joseph M.; Cornaglia, Mary Anne; Maggs, Jill; Samuel, John; Traylor, Joel; Marcus, Carole L.

    2014-01-01

    Study Objectives: Alternative therapies for childhood obstructive sleep apnea syndrome (OSAS) are needed as OSAS may persist despite adenotonsillectomy, and continuous positive airway pressure (CPAP) adherence is low. Nasal expiratory positive airway pressure (NEPAP) devices have not been studied in children. We hypothesized that NEPAP would result in polysomnographic improvement. Further, we aimed to determine NEPAP adherence, effects on sleepiness, behavior, and quality of life. Methods: A randomized, double-blind, placebo-controlled, crossover pilot study was performed. CPAP candidates, 8-16 years old, underwent NEPAP and placebo polysomnograms. Subjects with ≥ 50% reduction in the apnea hypopnea index (AHI) from placebo to NEPAP night or AHI < 5/h on NEPAP night wore NEPAP at home for 30 days. Adherence was assessed by daily phone calls/emails and collecting used devices. Results: Fourteen subjects (age 13.4 ± 1.9 years, BMI z-scores 2.2 ± 1 [mean ± SD]) were studied. There was significant improvement in the obstructive apnea index with NEPAP vs. placebo: 0.6 (0-21.1)/h vs. 4.2 (0-41.9)/h (median [range], p = 0.010) and trends for improvement in other polysomnographic parameters. However, responses were variable, with 3 subjects not improving and 2 worsening. Older children and those with less hypercapnia had a better response. Eight subjects were sent home with devices; one was lost to follow-up, and adherence in the remainder was 83% of nights; these subjects had a significant improvement in sleepiness and quality of life. Conclusions: NEPAP devices are a potential alternative therapy for OSAS in a small subset of children. Due to variability in individual responses, efficacy of NEPAP should be evaluated with polysomnography. Clinical Trial Registration: www.clinicaltrials.gov, identifier: NCT01768065 Citation: Kureshi SA, Gallagher PR, McDonough JM, Cornaglia MA, Maggs J, Samuel J, Traylor J, Marcus CL. Pilot study of nasal expiratory positive airway

  13. Pressure mapping at orthopaedic joint interfaces with fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Mohanty, Lipi; Tjin, Swee Chuan

    2006-02-01

    We present the concept of a fiber-optic sensor that can be used for pressure mapping at the prosthetic knee joint, in vitro and in vivo. An embedded array of fiber Bragg gratings is used to measure the load on the tibial spacer. The sensor gives the magnitude and the location of the applied load. The effect of material properties on the sensitivity of each subgrating is presented. The wavelength-shift maps show the malalignment of implants and demonstrate the potential of this sensor for use during total knee arthroplasty.

  14. Effects of Nocturnal Continuous Positive Airway Pressure Therapy in Patients with Resistant Hypertension and Obstructive Sleep Apnea

    PubMed Central

    Dernaika, Tarek A.; Kinasewitz, Gary T.; Tawk, Maroun M.

    2009-01-01

    Study Objective: To examine the long-term effects of continuous positive airway pressure (CPAP) therapy on blood pressure (BP) in patients with obstructive sleep apnea and resistant hypertension. Methods: Study subjects were 98 patients with obstructive sleep apnea syndrome and hypertension who had 3 or more documented daytime BP measurements taken within 3 months of enrollment and every 3 months after CPAP initiation for 1 year. Resistant hypertension was defined as daytime BP of at least 140 mm Hg systolic or 90 mm Hg diastolic, despite the use of 3 or more antihypertensive medications. Patients in the resistant hypertension group (n = 42) were compared with subjects with controlled hypertension (n = 56). Results: Mean difference in mean arterial pressure was −5.6 (95% confidence interval [CI] −2.0 to −8.7 mm Hg; p = 0.03) in the resistant group and −0.8 mm Hg (95% CI −2.9 to 3.3 mm Hg; p = 0.53) in patients with controlled BP at the end of follow up period. CPAP permitted de-escalation of antihypertensive treatment in 71% of subjects with resistant hypertension but did not significantly alter the antihypertensive regimen in the controlled group. Multivariate regression analysis showed that baseline BP (odds ratio 5.4, 95% CI 2.3 to 8.9; p = 0.01) and diuretic therapy (odds ratio = 3.2, 95% CI 1.8 to 6.1; p = 0.02), but not apnea-hypopnea index or hours of CPAP use, were independently associated with a decrease in mean arterial pressure after 12 months of CPAP therapy. Conclusion: In this observational study, CPAP was associated with different effects on blood pressure control in hypertensive patients with sleep apnea. A beneficial response to CPAP therapy was found mainly in subjects with the most severe hypertensive disease. Citation: Dernaika TA; Kinasewitz GT; Tawk MM. Effects of nocturnal continuous positive airway pressure therapy in patients with resistant hypertension and obstructive sleep apnea. J Clin Sleep Med 2009;5(2):103–107. PMID

  15. Computation of flow pressure fields from magnetic resonance velocity mapping.

    PubMed

    Yang, G Z; Kilner, P J; Wood, N B; Underwood, S R; Firmin, D N

    1996-10-01

    Magnetic resonance phase velocity mapping has unrivalled capacities for acquiring in vivo multi-directional blood flow information. In this study, the authors set out to derive both spatial and temporal components of acceleration, and hence differences of pressure in a flow field using cine magnetic resonance velocity data. An efficient numerical algorithm based on the Navier-Stokes equations for incompressible Newtonian fluid was used. The computational approach was validated with in vitro flow phantoms. This work aims to contribute to a better understanding of cardiovascular dynamics and to serve as a basis for investigating pulsatile pressure/flow relationships associated with normal and impaired cardiovascular function. PMID:8892202

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

    PubMed Central

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

    2013-01-01

    Introduction Results from a previous study showed that sexuality was negatively affected in females with untreated obstructive sleep apnea (OSA). Data are sparse on the long-term effects of nocturnal continuous positive airway pressure (CPAP) treatment on sexual difficulties and sexual distress in female patients with OSA. Aim The aim of the present study was to investigate the effects after 1 year of CPAP treatment on sexual difficulties, sexual distress, and manifest sexual dysfunction in female patients with OSA. The effect of CPAP on life satisfaction was also investigated. Methods Fifty-four therapy-compliant, female patients (age 22–71) received a survey before and after 1 year of nocturnal CPAP treatment. The questions on this survey were drawn from three self-administered questionnaires: two on sexuality and one on life satisfaction. The results were compared with a population sample. The Epworth Sleepiness Scale was used for assessment of daytime sleepiness. Main Outcome Measures The Female Sexual Function Index, Female Sexual Distress Scale, Manifest Female Sexual Dysfunction, four questions from Life Satisfaction 11, and the Epworth Sleepiness Scale were all used to measure outcome. Results In total, 44 patients responded to the survey (81% response rate). The results were a significant, positive change in manifest female sexual dysfunction, but no significant changes in isolated sexual difficulties or sexual distress. Daytime sleepiness significantly decreased after 1 year. The results from the Life Satisfaction 11 questionnaire remained unchanged after 1 year. Conclusions After 1 year of CPAP treatment, female patients with OSA reported reduced manifest sexual dysfunction. However, it cannot be concluded if this result is due to CPAP treatment alone. Furthermore, reduced daytime tiredness was found in the surveyed population. CPAP treatment, per se, does not seem to affect partner relationships. Petersen M, Kristensen E, Berg S, and Midgren B. Long

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

    NASA Astrophysics Data System (ADS)

    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.

  18. The effect of obstructive sleep apnea and treatment with continuous positive airway pressure on stroke rehabilitation: rationale, design and methods of the TOROS study

    PubMed Central

    2014-01-01

    Background Obstructive sleep apnea is a common sleep disorder in stroke patients. Obstructive sleep apnea is associated with stroke severity and poor functional outcome. Continuous positive airway pressure seems to improve functional recovery in stroke rehabilitation. To date, the effect of continuous positive airway pressure on cognitive functioning in stroke patients is not well established. The current study will investigate the effectiveness of continuous positive airway pressure on both cognitive and functional outcomes in stroke patients with obstructive sleep apnea. Methods/Design A randomized controlled trial will be conducted on the neurorehabilitation unit of Heliomare, a rehabilitation center in the Netherlands. Seventy stroke patients with obstructive sleep apnea will be randomly allocated to an intervention or control group (n = 2×35). The intervention will consist of four weeks of continuous positive airway pressure treatment. Patients allocated to the control group will receive four weeks of treatment as usual. Outcomes will be assessed at baseline, immediately after the intervention and at two-month follow-up. In a supplementary study, these 70 patients with obstructive sleep apnea will be compared to 70 stroke patients without obstructive sleep apnea with respect to cognitive and functional status at rehabilitation admission. Additionally, the societal participation of both groups will be assessed at six months and one year after inclusion. Discussion This study will provide novel information on the effects of obstructive sleep apnea and its treatment with continuous positive airway pressure on rehabilitation outcomes after stroke. Trial registration Trial registration number: Dutch Trial Register NTR3412 PMID:24568360

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

    PubMed

    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

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

    PubMed Central

    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 assistance has not been determined. Furthermore, it is unclear whether the effects of partial ventilatory support depend on acute lung injury (ALI) etiology. This study aimed to investigate the impact of spontaneous and time-cycled control breaths during BIVENT on the lung and diaphragm in experimental pulmonary (p) and extrapulmonary (exp) ALI. Methods This was a prospective, randomized, controlled experimental study of 60 adult male Wistar rats. Mild ALI was induced by Escherichia coli lipopolysaccharide either intratracheally (ALIp) or intraperitoneally (ALIexp). After 24 hours, animals were anesthetized and further randomized as follows: (1) pressure-controlled ventilation (PCV) with tidal volume (Vt) = 6 ml/kg, respiratory rate = 100 breaths/min, PEEP = 5 cmH2O, and inspiratory-to-expiratory ratio (I:E) = 1:2; or (2) BIVENT with three spontaneous and time-cycled control breath modes (100, 75, and 50 breaths/min). BIVENT was set with two levels of CPAP (Phigh = 10 cmH2O and Plow = 5 cmH2O). Inspiratory time was kept constant (Thigh = 0.3 s). Results BIVENT was associated with reduced markers of inflammation, apoptosis, fibrogenesis, and epithelial and endothelial cell damage in lung tissue in both ALI models when compared to PCV. The inspiratory effort during spontaneous breaths increased during BIVENT-50 in both ALI models. In ALIp, alveolar collapse was higher in BIVENT-100 than PCV, but decreased during BIVENT-50, and diaphragmatic injury was lower during BIVENT-50 compared

  1. Pressure Mapping Mat for Tele-Home Care Applications

    PubMed Central

    Saenz-Cogollo, Jose Francisco; Pau, Massimiliano; Fraboni, Beatrice; Bonfiglio, Annalisa

    2016-01-01

    In this paper we present the development of a mat-like pressure mapping system based on a single layer textile sensor and intended to be used in home environments for monitoring the physical condition of persons with limited mobility. The sensor is fabricated by embroidering silver-coated yarns on a light cotton fabric and creating pressure-sensitive resistive elements by stamping the conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) at the crossing points of conductive stitches. A battery-operated mat prototype was developed and includes the scanning circuitry and a wireless communication module. A functional description of the system is presented together with a preliminary experimental evaluation of the mat prototype in the extraction of plantar pressure parameters. PMID:26978369

  2. Upper Airway Collapsibility During Wakefulness in Children with Sleep Disordered Breathing, as Determined by the Negative Expiratory Pressure Technique

    PubMed Central

    Carrera, Helena Larramona; McDonough, Joseph M.; Gallagher, Paul R.; Pinto, Swaroop; Samuel, John; DiFeo, Natalie; Marcus, Carole L.

    2011-01-01

    Study Objectives: Upper airway (UA) collapsibility is a major factor in the pathophysiology of sleep disordered breathing (SDB). We hypothesized that the negative expiratory pressure (NEP) technique could distinguish between normal children and children with SDB even during wakefulness. Design: During wakefulness, NEP of −5 and −10 cm H2O was applied during expiration in seated and supine positions. UA muscle activity (EMG) was measured using intra-oral electrodes. Setting: Sleep laboratory. Participants: Twenty children with snoring, 20 with obstructive sleep apnea syndrome (OSAS), and 20 controls. Measurements and Results: The ratio of the area under the expiratory flow-volume curve during NEP compared to tidal breathing (RatioNEP) was calculated. Similarly, EMG area under the curve during NEP as a ratio of baseline was measured (RatioEMG). There were significant differences in RatioNEP between controls and snorers and controls and OSAS, at both pressures, in both the seated and supine positions; P < 0.0001 for all (e.g., RatioNEP at −5 cm H2O, seated: 1.8 ± 0.5, 2.1 ± 0.4, and 3.0 ± 0.6 for OSAS, snorers, and controls, respectively). However, no significant differences were found between snorers and OSAS. For RatioEMG, no significant differences were found between groups. Conclusions: RatioNEP distinguishes between normal children and children with SDB, be it snoring or OSAS, indicating that these children have a more collapsible UA even during wakefulness. However, it does not differentiate between snorers and OSAS, highlighting the important role of UA muscle activity during sleep. NEP technique does not elicit a different UA muscle activity response between controls and children with SDB. Citation: Carrera HL; McDonough JM; Gallagher PR; Pinto S; Samuel J; DiFeo N; Marcus CL. Upper airway collapsibility during wakefulness in children with sleep disordered breathing, as determined by the negative expiratory pressure technique. SLEEP 2011

  3. Pressure mapping with textile sensors for compression therapy monitoring.

    PubMed

    Baldoli, Ilaria; Mazzocchi, Tommaso; Paoletti, Clara; Ricotti, Leonardo; Salvo, Pietro; Dini, Valentina; Laschi, Cecilia; Francesco, Fabio Di; Menciassi, Arianna

    2016-08-01

    Compression therapy is the cornerstone of treatment in the case of venous leg ulcers. The therapy outcome is strictly dependent on the pressure distribution produced by bandages along the lower limb length. To date, pressure monitoring has been carried out using sensors that present considerable drawbacks, such as single point instead of distributed sensing, no shape conformability, bulkiness and constraints on patient's movements. In this work, matrix textile sensing technologies were explored in terms of their ability to measure the sub-bandage pressure with a suitable temporal and spatial resolution. A multilayered textile matrix based on a piezoresistive sensing principle was developed, calibrated and tested with human subjects, with the aim of assessing real-time distributed pressure sensing at the skin/bandage interface. Experimental tests were carried out on three healthy volunteers, using two different bandage types, from among those most commonly used. Such tests allowed the trends of pressure distribution to be evaluated over time, both at rest and during daily life activities. Results revealed that the proposed device enables the dynamic assessment of compression mapping, with a suitable spatial and temporal resolution (20 mm and 10 Hz, respectively). In addition, the sensor is flexible and conformable, thus well accepted by the patient. Overall, this study demonstrates the adequacy of the proposed piezoresistive textile sensor for the real-time monitoring of bandage-based therapeutic treatments. PMID:27334110

  4. Higher effective oronasal versus nasal continuous positive airway pressure in obstructive sleep apnea: Effect of mandibular stabilization

    PubMed Central

    Kaminska, M; Montpetit, A; Mathieu, A; Jobin, V; Morisson, F; Mayer, P

    2014-01-01

    BACKGROUND: In some individuals with obstructive sleep apnea (OSA), oronasal continuous positive airway pressure (CPAP) leads to poorer OSA correction than nasal CPAP. The authors hypothesized that this results from posterior mandibular displacement caused by the oronasal mask. OBJECTIVE: To test this hypothesis using a mandibular advancement device (MAD) for mandibular stabilization. METHODS: Subjects whose OSA was not adequately corrected by oronasal CPAP at pressures for which nasal CPAP was effective were identified. These subjects underwent polysomnography (PSG) CPAP titration with each nasal and oronasal mask consecutively, with esophageal pressure and leak monitoring, to obtain the effective pressure (Peff) of CPAP for correcting obstructive events with each mask (maximum 20 cmH2O). PSG titration was repeated using a MAD in the neutral position. Cephalometry was performed. RESULTS: Six subjects with mean (± SD) nasal Peff 10.4±3.0 cmH2O were studied. Oronasal Peff was greater than nasal Peff in all subjects, with obstructive events persisting at 20 cmH2O by oronasal mask in four cases. This was not due to excessive leak. With the MAD, oronasal Peff was reduced in three subjects, and Peff <20 cmH2O could be obtained in two of the four subjects with Peff >20 cmH2O by oronasal mask alone. Subjects’ cephalometric variables were similar to published norms. CONCLUSION: In subjects with OSA with higher oronasal than nasal Peff, this is partially explained by posterior mandibular displacement caused by the oronasal mask. Combination treatment with oronasal mask and MAD may be useful in some individuals if a nasal mask is not tolerated. PMID:24791252

  5. Effects of Continuous Positive Airway Pressure on Neurocognitive Function in Obstructive Sleep Apnea Patients: The Apnea Positive Pressure Long-term Efficacy Study (APPLES)

    PubMed Central

    Kushida, Clete A.; Nichols, Deborah A.; Holmes, Tyson H.; Quan, Stuart F.; Walsh, James K.; Gottlieb, Daniel J.; Simon, Richard D.; Guilleminault, Christian; White, David P.; Goodwin, James L.; Schweitzer, Paula K.; Leary, Eileen B.; Hyde, Pamela R.; Hirshkowitz, Max; Green, Sylvan; McEvoy, Linda K.; Chan, Cynthia; Gevins, Alan; Kay, Gary G.; Bloch, Daniel A.; Crabtree, Tami; Dement, William C.

    2012-01-01

    Study Objective: To determine the neurocognitive effects of continuous positive airway pressure (CPAP) therapy on patients with obstructive sleep apnea (OSA). Design, Setting, and Participants: The Apnea Positive Pressure Long-term Efficacy Study (APPLES) was a 6-month, randomized, double-blind, 2-arm, sham-controlled, multicenter trial conducted at 5 U.S. university, hospital, or private practices. Of 1,516 participants enrolled, 1,105 were randomized, and 1,098 participants diagnosed with OSA contributed to the analysis of the primary outcome measures. Intervention: Active or sham CPAP Measurements: Three neurocognitive variables, each representing a neurocognitive domain: Pathfinder Number Test-Total Time (attention and psychomotor function [A/P]), Buschke Selective Reminding Test-Sum Recall (learning and memory [L/M]), and Sustained Working Memory Test-Overall Mid-Day Score (executive and frontal-lobe function [E/F]) Results: The primary neurocognitive analyses showed a difference between groups for only the E/F variable at the 2 month CPAP visit, but no difference at the 6 month CPAP visit or for the A/P or L/M variables at either the 2 or 6 month visits. When stratified by measures of OSA severity (AHI or oxygen saturation parameters), the primary E/F variable and one secondary E/F neurocognitive variable revealed transient differences between study arms for those with the most severe OSA. Participants in the active CPAP group had a significantly greater ability to remain awake whether measured subjectively by the Epworth Sleepiness Scale or objectively by the maintenance of wakefulness test. Conclusions: CPAP treatment improved both subjectively and objectively measured sleepiness, especially in individuals with severe OSA (AHI > 30). CPAP use resulted in mild, transient improvement in the most sensitive measures of executive and frontal-lobe function for those with severe disease, which suggests the existence of a complex OSA-neurocognitive relationship

  6. Use of bilevel positive airway pressure (BIPAP) in end-stage patients with cystic fibrosis awaiting lung transplantation.

    PubMed

    Caronia, C G; Silver, P; Nimkoff, L; Gorvoy, J; Quinn, C; Sagy, M

    1998-09-01

    Nine consecutive end-stage patients with cystic fibrosis (CF) awaiting lung transplantation were admitted to the pediatric intensive care unit (PICU) in respiratory decompensation. They all received noninvasive bilevel positive airway pressure (BIPAP) support and were evaluated to determine whether or not it improved their oxygenation and provided them with long-term respiratory stability. BIPAP was applied to all patients after a brief period of assessment of their respiratory status. Inspiratory and expiratory positive airway pressures (IPAP, EPAP) were initially set at 8 and 4 cm H2O respectively. IPAP was increased by increments of 2 cm H2O and EPAP was increased by 1 cm H2O increments until respiratory comfort was achieved and substantiated by noninvasive monitoring. Patients were observed in the PICU for 48 to 72 hours and then discharged to home with instructions to apply BIPAP during night sleep and whenever subjectively required. Regular follow-up visits were scheduled through the hospital-based CF clinic. The patients' final IPAP and EPAP settings ranged from 14 to 18 cm H2O and 4 to 8 cm H2O, respectively. All nine patients showed a marked improvement in their respiratory status with nocturnal use of BIPAP at the time of discharge from the PICU. Their oxygen requirement dropped from a mean of 4.6 +/- 1.1 L/min to 2.3 +/- 1.5 L/min (P < 0.05). Their mean respiratory rate decreased from 34 +/- 4 to 28 +/- 5 breaths per minute (P < 0.05). The oxygen saturation of hemoglobin measured by pulse oximetry, significantly increased from a mean of 80% +/- 15% to 91% +/- 5% (P < 0.05). The patients have been followed up for a period of 2 to 43 months and have all tolerated the use of home nocturnal BIPAP without any reported discomfort. Six patients underwent successful lung transplantation after having utilized nocturnal BIPAP for 2, 6, 14, 15, 26, and 43 months, respectively. Three patients have utilized home BIPAP support for 2, 3, and 19 months, respectively

  7. Sleep Apnea Related Risk of Motor Vehicle Accidents is Reduced by Continuous Positive Airway Pressure: Swedish Traffic Accident Registry Data

    PubMed Central

    Karimi, Mahssa; Hedner, Jan; Häbel, Henrike; Nerman, Olle; Grote, Ludger

    2015-01-01

    Study Objectives: Obstructive sleep apnea (OSA) is associated with an increased risk of motor vehicle accidents (MVAs). The rate of MVAs in patients suspected of having OSA was determined and the effect of continuous positive airway pressure (CPAP) was investigated. Design: MVA rate in patients referred for OSA was compared to the rate in the general population using data from the Swedish Traffic Accident Registry (STRADA), stratified for age and calendar year. The risk factors for MVAs, using demographic and polygraphy data, and MVA rate before and after CPAP were evaluated in the patient group. Setting: Clinical sleep laboratory and population based control (n = 635,786). Patients: There were 1,478 patients, male sex 70.4%, mean age 53.6 (12.8) y. Interventions: CPAP. Measurements and Results: The number of accidents (n = 74) among patients was compared with the expected number (n = 30) from a control population (STRADA). An increased MVA risk ratio of 2.45 was found among patients compared with controls (P < 0.001). Estimated excess accident risk was most prominent in the elderly patients (65–80 y, seven versus two MVAs). In patients, driving distance (km/y), EDS (Epworth Sleepiness score ≥ 16), short habitual sleep time (≤ 5 h/night), and use of hypnotics were associated with increased MVA risk (odds ratios 1.2, 2.1, 2.7 and 2.1, all P ≤ 0.03). CPAP use ≥ 4 h/night was associated with a reduction of MVA incidence (7.6 to 2.5 accidents/1,000 drivers/y). Conclusions: The motor vehicle accident risk in this large cohort of unselected patients with obstructive sleep apnea suggests a need for accurate tools to identify individuals at risk. Sleep apnea severity (e.g., apnea-hypopnea index) failed to identify patients at risk. Citation: Karimi M, Hedner J, Häbel H, Nerman O, Grote L. Sleep apnea related risk of motor vehicle accidents is reduced by continuous positive airway pressure: Swedish traffic accident registry data. SLEEP 2015;38(3):341–349. PMID

  8. Methods of airway resistance assessment.

    PubMed

    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

  9. Airway occlusion pressure and diaphragm global electromyogram analysis for evaluation of inspiratory muscle drive and neuromechanical coupling in cattle.

    PubMed

    Desmecht, D J; Linden, A S; Rollin, F A; Lekeux, P M

    1994-06-01

    Although healthy and diseased bovine respiratory tracts have been intensively studied during the last years, to the authors' knowledge, there have been no attempts to objectively examine the inspiratory drive from the brain to the nerves and muscles and its transformation in pressure. Such technique would be useful in assessing the possibility of altered ventilatory drive or inspiratory muscle fatigue in the context of an animal with ventilatory failure. The relation among ventilation, airway opening occlusion pressure generated 100 milliseconds after onset of inspiration (Pawo100ms) and 6 indexes describing diaphragmatic electromyographic activity (EMGdi) recorded via implanted fishhooks was evaluated during free and impeded CO2 rebreathing in 6 young bulls. The best significant linear correlations (r > 0.8) with inspiratory center afferent stimulation, as judged by end-tidal CO2 concentration in expired air, were found for Pawo100ms, peak moving time average or variance EMGdi, and mean integrated EMGdi, whatever had been the respiratory impedance. However, with an inspiratory load, Pawo100ms responses systematically had greater increase for a given change in the driving EMGdi, implying dependence of the former not only on neural input, but also on configurational factors that determine inspiratory muscle excitation-pressure generation couplings. The reproducibility of EMGdi absolute values and changes was satisfactory up to 10 hours, but could not be repeated from one day to the other. It was concluded that, provided the constancy of the electrical coupling of the recording system to the tissue being studied is ensured, specific EMGdi and Pawo100ms values correlate reliably with amount of CO2 during free and loaded breathing.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7944009

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

    PubMed Central

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

    2014-01-01

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

  11. The Impact of Obstructive Sleep Apnoea and Nasal Continuous Positive Airway Pressure on Circulating Ischaemia-Modified Albumin Concentrations

    PubMed Central

    Uygur, Firat; Tanriverdi, Hakan; Can, Murat; Ornek, Tacettin; Erboy, Fatma; Altinsoy, Bulent; Atalay, Figen; Damar, Murat; Kokturk, Furuzan; Tor, Meltem

    2016-01-01

    The aim of the present study was to evaluate the impact of obstructive sleep apnoea syndrome (OSAS) and the effects of nasal continuous positive airway pressure (CPAP) on circulating ischaemia-modified albumin (IMA) concentrations. The study included 97 newly diagnosed OSAS patients and 30 nonapnoeic controls. Blood samples were obtained in the morning after polysomnography. After 3 months of CPAP treatment, 31 patients with moderate-severe OSAS were reassessed for serum IMA concentrations. Significantly higher serum IMA concentrations were measured in the OSAS group than in the control group [0.518 ± 0.091 absorbance units (ABSU), 0.415 ± 0.068 ABSU, P < 0.001]. Serum IMA concentrations correlated significantly with the apnoea-hypopnoea index, mean SaO2, desaturation index, and C-reactive protein concentrations. Multiple logistic regression analyses showed that OSAS increased the serum IMA concentration independent of age, sex, body mass index, smoking habit, and cardiovascular disease. After 3 months of treatment with CPAP, OSAS patients had significantly lower serum IMA concentrations (0.555 ± 0.062 ABSU to 0.431 ± 0.063 ABSU, P < 0.001). The results showed that OSAS is associated with elevated concentrations of IMA, which can be reversed by effective CPAP treatment. PMID:26903714

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

    PubMed Central

    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

  13. Bi-level positive airway pressure (BiPAP) ventilation in an infant with central hypoventilation syndrome.

    PubMed

    Villa, M P; Dotta, A; Castello, D; Piro, S; Pagani, J; Palamides, S; Ronchetti, R

    1997-07-01

    A 4-month-old baby girl, after a period of apparent good health, began to have aphonia, dyspnea, difficulties with swallowing, cyanosis, apnea, and hypopnea during sleep that resulted in admission to an intensive care unit for intubation and mechanical ventilation. At the age of 9 months she was admitted to our hospital with a possible diagnosis of central hypoventilation syndrome. A polysomnographic study showed apnea and hypopnea (apnea + hypopnea index = 47.1), hypercapnia (mean end-tidal PCO2 89 +/- 15.0 mmHg), and arterial desaturation (mean SaO2 91 +/- 1.7%; lowest SaO2 < 50%; 68% of total sleep time at SaO2 below 93%); the study also showed an absent ventilatory response to CO2, absent cardiac responses to apnea during sleep, and right ventricular hypertrophy. Nocturnal nasal bi-level positive airway pressure (BIPAP), applied initially at 6 cmH2O and gradually increased to 16 cmH2O, caused the sleep-related abnormal respiratory events to disappear. End-tidal PCO2 decreased to 39 mmHg, and SaO2 increased to 94%. After 6 months of nocturnal BiPAP ventricular right hypertrophy reversed and arrested growth and hypotonia normalized. The child has tolerated and has remained on BiPAP support up to her current age of 3 years and continues to use this form of ventilatory assistance without difficulties. PMID:9261857

  14. Auto-adjusting positive airway pressure in children with sickle cell anemia: results of a phase I randomized controlled trial.

    PubMed

    Marshall, Melanie J; Bucks, Romola S; Hogan, Alexandra M; Hambleton, Ian R; Height, Susan E; Dick, Moira C; Kirkham, Fenella J; Rees, David C

    2009-07-01

    Low nocturnal oxygen saturation (SpO(2)) is implicated in complications of Sickle Cell Anemia (SCA). Twenty-four children with SCA were randomized to receive overnight auto-adjusting continuous positive airway pressure (auto-CPAP) with supplemental oxygen, if required, to maintain SpO(2) >or=94% or as controls. We assessed adherence, safety, sleep parameters, cognition and pain. Twelve participants randomized to auto-CPAP (3 with oxygen) showed improvement in Apnea/Hypopnea Index (p<0.001), average desaturation events >3%/hour (p=0.02), mean nocturnal SpO(2) (p=0.02) and cognition. Primary efficacy endpoint (Processing Speed Index) showed no group differences (p=0.67), but a second measure of processing speed and attention (Cancellation) improved in those receiving treatment (p=0.01). No bone marrow suppression, rebound pain or serious adverse event resulting from auto-CPAP use was observed. Six weeks of auto-CPAP therapy is feasible and safe in children with SCA, significantly improving sleep-related breathing disorders and at least one aspect of cognition. PMID:19570752

  15. Rhythmic Pressure Waves Induce Mucin5AC Expression via an EGFR-Mediated Signaling Pathway in Human Airway Epithelial Cells

    PubMed Central

    Liu, Chunyi; Li, Qi; Kolosov, Victor P.; Perelman, Juliy M.

    2013-01-01

    Rhythmic pressure waves (RPW), mimicking the mechanical forces generated during normal breathing, play a key role in airway surface liquid (ASL) homeostasis. As a major component of ASL, we speculated that the mucin5AC (MUC5AC) expression must also be regulated by RPW. However, fewer researches have focused on this question. Therefore, our aim was to test the effect and mechanism of RPW on MUC5AC expression in cultured human bronchial epithelial cells. Compared with the relevant controls, the transcriptional level of MUC5AC and the protein expressions of MUC5AC, the phospho-epidermal growth factor receptor (p-EGFR), phospho-extracellular signal-related kinase (p-ERK), and phospho-Akt (p-Akt) were all significantly increased after mechanical stimulation. However, this effect could be significantly attenuated by transfecting with EGFR-siRNA. Similarly, pretreating with the inhibitor of ERK or phosphatidylinositol 3-kinases (PI3K)/Akt separately or jointly also significantly reduced MUC5AC expression. Collectively, these results indicate that RPW modulate MUC5AC expression via the EGFR-PI3K-Akt/ERK-signaling pathway in human bronchial epithelial cells. PMID:23768102

  16. Continuous Positive Airway Pressure versus Mechanical Ventilation on the First Day of Life in Very Low-Birth-Weight Infants.

    PubMed

    Flannery, Dustin D; O'Donnell, Elizabeth; Kornhauser, Mike; Dysart, Kevin; Greenspan, Jay; Aghai, Zubair H

    2016-08-01

    Objective The objective of this study was to determine differences in the incidence of bronchopulmonary dysplasia (BPD) or death in very low-birth-weight (VLBW) infants managed successfully on continuous positive airway pressure (CPAP) versus mechanical ventilation on the first day of life (DOL). Study Design This is a retrospective analysis of the Alere neonatal database for infants born between January 2009 and December 2014, weighing ≤ 1,500 g. Baseline demographics, clinical characteristics, and outcomes were compared between the two groups. Multivariable regression analysis was performed to control the variables that differ in bivariate analysis. Results In this study, 4,629 infants (birth weight 1,034 ± 290 g, gestational age 28.1 ± 2.5 weeks) met the inclusion criteria. The successful use of early CPAP was associated with a significant reduction in BPD or death (p < 0.001), as well as days to room air, decreased oxygen use at discharge, lower risk for severe intraventricular hemorrhage, and patent ductus arteriosus requiring surgical ligation (p < 0.001 for all outcomes). Conclusion Successful use of early CPAP on the first DOL in VLBW infants is associated with a reduced risk of BPD or death. PMID:27057767

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

    PubMed

    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

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

    PubMed Central

    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

  19. Oxidative stress and quality of life in elderly patients with obstructive sleep apnea syndrome: are there differences after six months of Continuous Positive Airway Pressure treatment?

    PubMed Central

    Yagihara, Fabiana; Lucchesi, Ligia Mendonça; D'Almeida, Vânia; de Mello, Marco Túlio; Tufik, Sergio; Bittencourt, Lia Rita Azeredo

    2012-01-01

    OBJECTIVES: This study evaluated the effect of Continuous Positive Airway Pressure treatment on oxidative stress parameters and the quality of life of elderly patients with obstructive sleep apnea syndrome. METHODS: In total, 30 obstructive sleep apnea syndrome patients and 27 subjects without obstructive sleep apnea syndrome were included in this study. Both groups underwent quality of life and oxidative stress evaluations at baseline and after six months. Polysomnography was performed in both groups at baseline and a second time in the obstructive sleep apnea syndrome group after six months of Continuous Positive Airway Pressure treatment. All of the variables were compared between the control and obstructive sleep apnea syndrome groups in this prospective case-control study. RESULTS: The baseline concentrations of the antioxidant enzyme catalase were higher in the obstructive sleep apnea syndrome group than the control group. After Continuous Positive Airway Pressure treatment, the obstructive sleep apnea syndrome group exhibited a reduction in the level of oxidative stress, as indicated by a decrease in the level of lipid peroxidation measured by the malondialdehyde (MDA) concentration [pre: 2.7 nmol malondialdehyde/mL (95% 1.6-3.7) vs. post: 1.3 nmol MDA/mL (0.7-1.9), p<0.01]. Additionally, improvements were observed in two domains covered by the SF-36 questionnaire: functional capacity [pre: 77.4 (69.2-85.5) vs. post: 83.4 (76.9-89.9), p = 0.002] and pain [pre: 65.4 (52.8-78.1) vs. post: 77.8 (67.2-88.3), p = 0.004]. CONCLUSION: Our study demonstrated that the use of Continuous Positive Airway Pressure to treat obstructive sleep apnea syndrome in elderly patients reduced oxidative stress and improved the quality of life. PMID:22760893

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

    PubMed Central

    Brigatto, Patrícia; Carbinatto, Jéssica C.; Costa, Carolina M.; Montebelo, Maria I. L.; Rasera-Júnior, Irineu; 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 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 (p<0.05), regardless of the technique used, with no significant difference among the techniques (p>0.05). 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. PMID:25590448

  1. Airway Pressure Release Ventilation and High-Frequency Oscillatory Ventilation: Potential Strategies to Treat Severe Hypoxemia and Prevent Ventilator-Induced Lung Injury.

    PubMed

    Facchin, Francesca; Fan, Eddy

    2015-10-01

    Although lifesaving, mechanical ventilation can itself be responsible for damage to lung parenchyma. This ventilator-induced lung injury is especially observed in already injured lungs of patients with ARDS. New ventilatory approaches are needed to safely treat patients with ARDS, and recent studies have suggested the potential utility of open-lung strategies. Airway pressure release ventilation (APRV) and high-frequency oscillatory ventilation (HFOV) are 2 different open-lung strategies that have been proposed to treat refractory hypoxemic respiratory failure while preventing ventilator-induced lung injury. APRV provides increased airway pressure as a potential recruitment mechanism and allows spontaneous breathing, with the potential benefits of decreased sedation, shorter duration of mechanical ventilation, and improvement in cardiac performance. HFOV delivers very small tidal volumes, to prevent volutrauma, at a constant (relatively high) mean airway pressure, thus avoiding atelectrauma. Despite their theoretical benefits, the utility of APRV and HFOV remains unproven and controversial for the routine treatment of ARDS in adult patients. This review is focused on the theoretical and practical aspects of APRV and HFOV, provides an overview of the current evidence, and addresses their possible use in the treatment of ARDS. PMID:26405188

  2. Computational simulation of human upper airway collapse using a pressure-/state-dependent model of genioglossal muscle contraction under laminar flow conditions

    PubMed Central

    Huang, Yaqi; Malhotra, Atul; White, David P.

    2012-01-01

    A three-element, pressure- and state (sleep and wake) -dependent contraction model of the genioglossal muscle was developed based on the microstructure of skeletal muscle and the cross-bridge theory. This model establishes a direct connection between the contractile forces generated in muscle fibers and the measured electromyogram signals during various upper airway conditions. This effectively avoids the difficulty of determining muscle shortening velocity during complex pharyngeal conditions when modeling the muscle’s contractile behaviors. The activation of the genioglossal muscle under different conditions was then simulated. A sensitivity analysis was performed to determine the effects of varying each modeled parameter on the muscle’s contractile behaviors. This muscle contraction model was then incorporated into our anatomically correct, two-dimensional computational model of the pharyngeal airway to perform a finite-element analysis of air flow, tissue deformation, and airway collapse. The model-predicted muscle deformations are consistent with previous observations regarding upper airway behavior in normal subjects. PMID:15831800

  3. A Comparison of the Effect of Nasal bi-level Positive Airway Pressure and Sigh-positive Airway Pressure on the Treatment of the Preterm Newborns Weighing Less than 1500 g Affiliated with Respiratory Distress Syndrome

    PubMed Central

    Sadeghnia, Alireza; Danaei, Navid; Barkatein, Behzad

    2016-01-01

    Background: Nowadays, administering noninvasive positive airway pressure (PAP) is considered as the building block for the management of respiratory distress syndrome (RDS). Since nasal continuous PAP (n-CPAP) established its roots as an interventional approach to treat RDS, there have always been concerns related to the increased work of breathing in newborns treated with this intervention. Therefore, respiratory support systems such as nasal bi-level PAP (N-BiPAP) and sigh-PAP (SiPAP) have been developed during the last decade. In this study, two respiratory support systems which, unlike n-CPAP, are categorized as cycled noninvasive ventilation, are studied. Methods: This study was a randomized clinical trial done on 74 newborns weighing 1500 g or less affiliated with RDS hospitalized in NICU at Al-Zahra Hospital from October 2012 to March 2014. Patients were randomly assigned to two respiratory support groups of N-BiPAP and SiPAP. Each group contained 37 newborns who were compared, according to their demographic characteristics, duration of noninvasive ventilation, the need to administer surfactant, apnea incidence, the need for mechanical ventilation, pneumothorax, intraventricular hemorrhage (IVH), patent ductus arteriosus (PDA), the duration of oxygen supplement administration, and chronic lung disease (CLD). Results: The average duration of noninvasive respiratory support, and the average duration of the need for oxygen supplement had no significant difference between the groups. Moreover, apnea incidence, the need for mechanical ventilation, pneumothorax, IVH, PDA, CLD, the need for the second dose of surfactant, and the death rate showed no significant difference in two groups. Conclusions: In this study, SiPAP showed no significant clinical preference over N-BiPAP in the treatment of the newborns with RDS weighing <1500 g. PMID:26941922

  4. Predictors of Long-Term Adherence to Continuous Positive Airway Pressure Therapy in Patients with Obstructive Sleep Apnea and Cardiovascular Disease in the SAVE Study

    PubMed Central

    Chai-Coetzer, Ching Li; Luo, Yuan-Ming; Antic, Nick A.; Zhang, Xi-Long; Chen, Bao-Yuan; He, Quan-Ying; Heeley, Emma; Huang, Shao-Guang; Anderson, Craig; Zhong, Nan-Shan; McEvoy, R. Doug

    2013-01-01

    Study Objectives: To determine the clinical variables that best predict long- term continuous positive airway pressure (CPAP) adherence among patients with cardiovascular disease who have obstructive sleep apnea (OSA). Design: 12-mo prospective within-trial observational study. Setting: Centers in China, Australia, and New Zealand participating in the Sleep Apnea cardioVascular Endpoints (SAVE) study. Patients: There were 275 patients age 45-70 y with cardiovascular disease (i.e., previously documented transient ischemic attack, stroke, or coronary artery disease) and OSA (4% oxygen desaturation index (ODI) > 12) who were randomized into the CPAP arm of the SAVE trial prior to July 1, 2010. Methods: Age, sex, country of residence, type of cardiovascular disease, baseline ODI, severity of sleepiness, and Hospital Anxiety and Depression Scale (HADS) scores plus CPAP side effects and adherence at 1 mo were entered in univariate analyses in an attempt to identify factors predictive of CPAP adherence at 12 mo. Variables with P < 0.2 were then included in a multivariate analysis using a linear mixed model with sites as a random effect and 12-mo CPAP use as the dependent outcome variable. Measurements and Results: CPAP adherence at 1, 6, and 12 mo was (mean ± standard deviation) 4.4 ± 2.0, 3.8 ± 2.3, and 3.3 ± 2.4 h/night, respectively. CPAP use at 1 mo (effect estimate ± standard error, 0.65 ± 0.07 per h increase, P < 0.001) and side effects at 1 mo (-0.24 ± 0.092 per additional side effect, P = 0.009) were the only independent predictors of 12- mo CPAP adherence. Conclusion: Continuous positive airway pressure use in patients with coexisting cardiovascular disease and moderate to severe obstructive sleep apnea decreases significantly over 12 months. This decline can be predicted by early patient experiences with continuous positive airway pressure (i.e., adherence and side effects at 1 month), raising the possibility that intensive early interventions could

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

    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

  7. Patients with obstructive sleep apnea exhibit genioglossus dysfunction that is normalized after treatment with continuous positive airway pressure.

    PubMed

    Carrera, M; Barbé, F; Sauleda, J; Tomás, M; Gómez, C; Agustí, A G

    1999-06-01

    Obstructive sleep apnea syndrome (OSAS) is characterized by repetitive episodes of pharyngeal closure during sleep. The pathogenesis of OSAS is unclear. We hypothesized that the genioglossus (GG), the most important pharyngeal dilator muscle, would be abnormal in patients with OSAS. Further, because treatment with continuous positive airway pressure (CPAP) is very effective clinically in these patients, we investigated the effects of CPAP upon the structure and function of the GG. We studied 16 patients with OSAS (nine of them at diagnosis and seven after having been under treatment with CPAP for at least 1 yr) and 11 control subjects in whom OSAS was excluded clinically. A biopsy of the GG was obtained in each subject, mounted in a tissue bath, and stimulated through platinum electrodes. The following measurements were obtained: maximal twitch tension, contraction time, half-relaxation time, the force-frequency relationship, and the response to a fatiguing protocol. The percentage of type I ("slow twitch") and type II ("fast twitch") fibers was also quantified. Patients with OSAS showed a greater GG fatigability than did control subjects (ANOVA, p < 0.001). Interestingly, this abnormality was entirely corrected by CPAP. Likewise, the percentage of type II fibers was significantly higher in patients with OSAS (59 +/- 4%) than in control subjects (39 +/- 4%, p < 0.001) and, again, these structural changes were corrected by CPAP (40 +/- 3%, p < 0.001). These results show that the function and structure of the GG is abnormal in patients with OSAS. Because these abnormalities are corrected by CPAP, we suggest that they are likely a consequence, not a cause, of the disease. PMID:10351945

  8. Restoring the salivary cortisol awakening response through nasal continuous positive airway pressure therapy in obstructive sleep apnea.

    PubMed

    Ghiciuc, Cristina Mihaela; Dima Cozma, Lucia Corina; Bercea, Raluca Mihaela; Lupusoru, Catalina Elena; Mihaescu, Traian; Szalontay, Andreea; Gianfreda, Angela; Patacchioli, Francesca Romana

    2013-10-01

    Partial and largely conflicting data are currently available on the interplay between obstructive sleep apnea (OSA) and hypothalamus-pituitary-adrenal axis (HPA) activity in adult obese men. This study was performed to evaluate the daily trajectories of salivary cortisol, specifically with respect to the salivary cortisol awakening response (CAR), a common method used to assess HPA axis activity. The main findings of this study were that adult male obese subjects who were newly diagnosed with severe OSA showed the following: (1) a flattening of the CAR; (2) levels of cortisol at awakening that were lower than those of the controls; and (3) maintenance of the physiological circadian activity of the HPA axis, with the highest hormone concentrations produced in the morning and the lowest in the evening. This study was also designed to investigate the effects of 3 and 6 mos of treatment with continuous airways positive pressure (CPAP). CPAP use resulted in a significant recovery of the sleep patterns disrupted by OSA; moreover, mild neuropsychological signs of depression and anxiety in severe OSA patients were concomitantly progressively improved by CPAP treatment. Furthermore, this study reports that 3 and 6 mos of CPAP therapy restored the presence of CAR and was able to significantly reduce the difference in the morning cortisol levels between the OSA and control groups. In conclusion, we report here that compared with obese nonapneic matched controls, OSA patients present a dysregulation of HPA axis activity, as shown by the flattening of the diurnal pattern of cortisol production in response to repeated challenge due to hypoxia and sleep fragmentation. This dysregulation was especially detectable in the first hour after awakening and restored after 3 and 6 mos of treatment with CPAP. PMID:23859257

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

    PubMed

    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

  10. Management of the artificial airway.

    PubMed

    Branson, Richard D; Gomaa, Dina; Rodriquez, Dario

    2014-06-01

    Management of the artificial airway includes securing the tube to prevent dislodgement or migration as well as removal of secretions. Preventive measures include adequate humidification and appropriate airway suctioning. Monitoring airway patency and removing obstruction are potentially life-saving components of airway management. Cuff pressure management is important for preventing aspiration and mucosal damage as well as assuring adequate ventilation. A number of new monitoring techniques have been introduced, and automated cuff pressure control is becoming more common. The respiratory therapist should be adept with all these devices and understand the appropriate application and management. PMID:24891202

  11. Sex differences of continuous positive airway pressure treatment on flow-mediated dilation in patients with obstructive sleep apnea syndrome

    PubMed Central

    Kallianos, Anastasios; Panoutsopoulos, Athanasios; Mermigkis, Christoforos; Kostopoulos, Konstantinos; Papamichail, Chrysanthi; Kokkonouzis, Ioannis; Kostopoulos, Christoforos; Nikolopoulos, Ioannis; Papaiwannou, Antonis; Lampaki, Sofia; Organtzis, John; Pitsiou, Georgia; Zarogoulidis, Paul; Trakada, Georgia

    2015-01-01

    Introduction There is growing research evidence suggesting the presence of endothelial dysfunction and systemic inflammation in patients with obstructive sleep apnea syndrome (OSAS). Continuous positive airway pressure (CPAP) is the most effective method for treating OSAS; nonetheless, the effects of CPAP on the aforementioned pathophysiologic pathways as well as on the systemic disease that result or coexist with the OSAS remain elusive. Aim To assess the effect of 3-month CPAP therapy on endothelial-dependent dilation, plasma levels of inflammatory markers, blood pressure (BP), and glucose control on male and female patients with OSAS. Methods Our study group consisted of 40 (24 males and 16 females) patients with no prior history of cardiovascular disease, with an apnea–hypopnea index ≥15, who were assigned to receive CPAP treatment. Measurements of flow-mediated dilation (FMD), 24-hour ambulatory BP, and blood analysis were performed at baseline and 3 months after CPAP therapy. Results Baseline FMD values were negatively correlated with the apnea–hypopnea index (r=−0.55, P=0.001). After 3 months of CPAP, there was an increase in the FMD values (5.40%±2.91% vs 3.13%±3.15%, P<0.05) and a significant reduction in the patients’ 24-hour systolic BP (122.82±11.88 mmHg vs 130.24±16.75 mmHg, P<0.05), diastolic BP (75.44±9.14 mmHg vs 79.68±11.09 mmHg, P<0.05), and pulse pressure (47.38±9.77 mmHg vs 52.72±11.38 mmHg, P<0.05); daytime systolic BP (125.76±12.69 mmHg vs 132.55±17.00 mmHg, P<0.05) and diastolic BP (77.88±10.39 mmHg vs 82.25±11.01 mmHg, P<0.05); nighttime systolic BP (118.17±13.16 mmHg vs 126.22±17.42 mmHg, P<0.05) and pulse pressure (46.61±10.76 mmHg vs 52.66±11.86 mmHg, P<0.05); and C-reactive protein and HbA1c levels (0.40 [0.40–0.70] mg/L vs 0.60 [0.40–0.84] mg/L and 5.45%±0.70% vs 5.95%±1.08%, respectively; P<0.05). When divided by sex, only male patients produced similar statistically significant results, while female

  12. Surgical Airway

    PubMed Central

    Patel, Sapna A; Meyer, Tanya K

    2014-01-01

    Close to 3% of all intubation attempts are considered difficult airways, for which a plan for a surgical airway should be considered. Our article provides an overview of the different types of surgical airways. This article provides a comprehensive review of the main types of surgical airways, relevant anatomy, necessary equipment, indications and contraindications, preparation and positioning, technique, complications, and tips for management. It is important to remember that the placement of a surgical airway is a lifesaving procedure and should be considered in any setting when one “cannot intubate, cannot ventilate”. PMID:24741501

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

    PubMed

    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

  14. Eszopiclone Improves Overnight Polysomnography and Continuous Positive Airway Pressure Titration: A Prospective, Randomized, Placebo-Controlled Trial

    PubMed Central

    Lettieri, Christopher J.; Quast, Timothy N.; Eliasson, Arn H.; Andrada, Teotimo

    2008-01-01

    for polysomnography and the need to improve efficiency, the routine use of nonbenzodiazepines as premedication for polysomnography should be considered. Citation: Lettieri CJ; Quast TN; Eliasson AH; Andrada T. Eszopiclone improves overnight polysomnography and continuous positive airway pressure titration: a prospective, randomized, placebo-controlled trial. SLEEP 2008;31(9):1310-1316. PMID:18788656

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

    SciTech Connect

    Goldstein, Jeffrey D.; Lawrence, Yaacov R.; 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; Segel, Michael J.; Peled, Nir; Symon, Zvi

    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.

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

    PubMed

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

    2016-01-01

    In this study, the prevalence of erectile dysfunction (ED) and serum sexual hormone levels were evaluated in men with obstructive sleep apnea (OSA). In these patients, the efficacy of continuous positive airway pressure (CPAP) was determined. The 207 men (mean age 44.0 ± 11.1 years) enrolled in the study were stratified within four groups based on their apnea-hypopnea index score: simple snoring (n = 32), mild OSA (n = 29), moderate OSA (n = 38), and severe OSA (n = 108). The International Index of Erectile Dysfunction-5 (IIEF-5) score was obtained from each patient, and blood samples for the analysis of sexual hormones (prolactin, luteotropin, follicle-stimulating hormone, estradiol, progestin, and testosterone) were drawn in the morning after polysomnography. The IIEF-5 test and serum sexual hormone measurements were repeated after 3 months of CPAP treatment in 53 men with severe OSA. The prevalence of ED was 60.6 % in OSA patients overall and 72.2 % in those with severe OSA. Compared with the simple snoring group, patients with severe OSA had significantly lower testosterone levels (14.06 ± 5.62 vs. 17.02 ± 4.68, p = .018) and lower IIEF-5 scores (16.33 ± 6.50 vs. 24.09 ± 1.94, p = .001). The differences in the other sexual hormones between groups were not significant. After 3 months of CPAP treatment, there were no significant changes in sexual hormone levels, but the IIEF-5 score had improved significantly (18.21 ± 4.05 vs. 19.21 ± 3.86, p = .001). Severe OSA patients have low testosterone concentration and high ED prevalence. IIEF-5 scores increased significantly after CPAP treatment, but there was no effect on serum testosterone levels. PMID:26370402

  17. Sustainable use of continuous positive airway pressure in extremely preterm infants during the first week after delivery

    PubMed Central

    Booth, C; Premkumar, M H; Yannoulis, A; Thomson, M; Harrison, M; Edwards, A D

    2006-01-01

    Background Early use of nasal continuous positive airway pressure (nCPAP) may reduce lung damage, but it is not clear how many extremely preterm infants can be cared for without mechanical ventilation on the first days after delivery. Objectives To describe our experience of nCPAP in infants born at <27 weeks' gestation and to determine the chance of reintubation of this group of extremely preterm infants. Methods A retrospective, observational study examined the period from November 2002 to October 2003, when efforts were made to extubate infants to nCPAP at the earliest opportunity. Data were collected on all infants born at <27 weeks' and gestation admitted to The Neonatal Intensive Care Unit, Queen Charlotte's and Chelsea Hospital, London, UK. The chance of an individual infant requiring reintubation within 48 h of delivery was estimated, calculating the predictive probability using a Bayesian approach, and oxygen requirements at 36 weeks' postmenstrual age were examined. Results 60 infants, 34 inborn and 26 ex utero transfers, were admitted; 7 infants admitted 24 h after birth were excluded and 5 died within 48 h. The mean birth weight was 788 g and the gestational age was 25.3 weeks. Extubation was attempted on day 1 in 21 of 52 infants on ventilators and was successful in 14; and on day 2 in 14 of 35 and successful in 10 of infants extubated within 48 h of delivery survived to discharge. 5 of 23 infants on mechanical ventilation at 48 h of age were on air at 36 weeks postmenstrual age, and 12 of 26 of those were on nCPAP at 48 h of age. The probability of an individual baby remaining on nCPAP was 66% (95% CI 46% to 86%) on day 1 and 80% (95% CI 60% to 99%) on day 2. The smallest infant to be successfully extubated was 660 g and the youngest gestational age was 23.8 weeks. Conclusions Extremely preterm infants can be extubated to nCPAP soon after delivery, with a reasonable probability of not requiring immediate reintubation. PMID

  18. The effect of bi-level positive airway pressure on postoperative pulmonary function following gastric surgery for obesity.

    PubMed

    Ebeo, C T; Benotti, P N; Byrd, R P; Elmaghraby, Z; Lui, J

    2002-09-01

    The severely obese patient has varying degrees of intrinsic reduction of expiratory flow rates and lung volumes. Thus, the severely obese patient is predisposed to postoperative atelectasis, ineffective clearing of respiratory secretions, and other pulmonary complications. This study evaluated the effect of bi-level positive airway pressure (BiPAP) on pulmonary function in obese patients following open gastric bypass surgery Patients with a body mass index (BMI) of at least 40 kg/m2 who were undergoing elective gastric bypass were eligible to be randomized to receive either BiPAP during the first 24 h postoperatively or conventional postoperative care. Patients with significant cardiovascular and pulmonary diseases were excluded from the study. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), peak expiratory flow rate (PEFR), and percent hemoglobin oxygen saturation (SpO2) were measured preoperatively, and on postoperative days 1, 2, and 3. Twenty-seven patients were entered in the study 14 received BiPAP and 13 received conventional postoperative care. There was no significant difference preoperatively between the study and control groups in regards to age, BMI, FVC, FEV1.0, PEFR or SpO2. Postoperatively expiratory flow was decreased in both groups. However, the FVC and FEV1.0 were significantly higher on each of the three consecutive postoperative days in the patients who received BiPAP therapy. The SpO2 was significantly decreased in the control group over the same time period. Prophylactic BiPAP during the first 12-24 h postoperatively resulted in significantly higher measures of pulmonary function in severely obese patients who had undergone elective gastric bypass surgery. These improved measures of pulmonary function, however, did not translate into fewer hospital days or a lower complication rate in our study population of otherwise healthy obese patients. Further study is necessary to determine if BiPAP therapy in the first 24

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Web-Based Access to Positive Airway Pressure Usage with or without an Initial Financial Incentive Improves Treatment Use in Patients with Obstructive Sleep Apnea

    PubMed Central

    Kuna, Samuel T.; Shuttleworth, David; Chi, Luqi; Schutte-Rodin, Sharon; Friedman, Eliot; Guo, Hengyi; Dhand, Sandeep; Yang, Lin; Zhu, Jingsan; Bellamy, Scarlett L.; Volpp, Kevin G.; Asch, David A.

    2015-01-01

    Study Objectives: We tested whether providing adults with obstructive sleep apnea (OSA) with daily Web-based access to their positive airway pressure (PAP) usage over 3 mo with or without a financial incentive in the first week improves adherence and functional outcomes. Setting: Academic- and community-based sleep centers. Participants: One hundred thirty-eight adults with newly diagnosed OSA starting PAP treatment. Interventions: Participants were randomized to: usual care, usual care with access to PAP usage, or usual care with access to PAP usage and a financial incentive. PAP data were transmitted daily by wireless modem from the participants' PAP unit to a website where hours of usage were displayed. Participants in the financial incentive group could earn up to $30/day in the first week for objective PAP use ≥ 4 h/day. Measurements and Results: Mean hours of daily PAP use in the two groups with access to PAP usage data did not differ from each other but was significantly greater than that in the usual care group in the first week and over 3 mo (P < 0.0001). Average daily use (mean ± standard deviation) during the first week of PAP intervention was 4.7 ± 3.3 h in the usual care group, and 5.9 ± 2.5 h and 6.3 ± 2.5 h in the Web access groups with and without financial incentive respectively. Adherence over the 3-mo intervention decreased at a relatively constant rate in all three groups. Functional Outcomes of Sleep Questionnaire change scores at 3 mo improved within each group (P < 0.0001) but change scores of the two groups with Web access to PAP data were not different than those in the control group (P > 0.124). Conclusions: Positive airway pressure adherence is significantly improved by giving patients Web access to information about their use of the treatment. Inclusion of a financial incentive in the first week had no additive effect in improving adherence. Citation: Kuna ST, Shuttleworth D, Chi L, Schutte-Rodin S, Friedman E, Guo H, Dhand S, Yang

  1. Visual Feedback of Continuous Bedside Pressure Mapping to Optimize Effective Patient Repositioning

    PubMed Central

    Scott, Ronald G.; Thurman, Kristen M.

    2014-01-01

    Objective: To evaluate the effectiveness of a new bedside pressure mapping technology for patient repositioning in a long-term acute care hospital. Approach: Bedside caregivers repositioned patients to the best of their abilities, using pillows and positioning aids without the visual feedback from a continuous bedside pressure mapping (CBPM) system. Once positioned, caregivers were shown the image from the CBPM system and allowed to make further adjustments to the patient position. Data from the CBPM device, in the form of visual screenshots and peak pressure values, were obtained after each repositioning phase. Caregivers provided feedback on repositioning with and without the CBPM system. Results: Screenshots displayed lower pressures when the visual feedback from the CBPM systems was utilized by caregivers. Lower peak pressure measurements were also evident when caregivers utilized the image from the CBPM systems. Overall, caregivers felt the system enabled more effective patient positioning and increased the quality of care they provided their patients. Innovation: This is the first bedside pressure mapping device to be continuously used in a clinical setting to provide caregivers and patients visual, instant feedback of pressure, thereby enhancing repositioning and offloading practices. Conclusion: With the visual feedback from the pressure mapping systems, caregivers were able to more effectively reposition patients, decreasing exposure to damaging high pressures. PMID:24804157

  2. Supraglottic airway devices.

    PubMed

    Ramachandran, Satya Krishna; Kumar, Anjana M

    2014-06-01

    Supraglottic airway devices (SADs) are used to keep the upper airway open to provide unobstructed ventilation. Early (first-generation) SADs rapidly replaced endotracheal intubation and face masks in > 40% of general anesthesia cases due to their versatility and ease of use. Second-generation devices have further improved efficacy and utility by incorporating design changes. Individual second-generation SADs have allowed more dependable positive-pressure ventilation, are made of disposable materials, have integrated bite blocks, are better able to act as conduits for tracheal tube placement, and have reduced risk of pulmonary aspiration of gastric contents. SADs now provide successful rescue ventilation in > 90% of patients in whom mask ventilation or tracheal intubation is found to be impossible. However, some concerns with these devices remain, including failing to adequately ventilate, causing airway damage, and increasing the likelihood of pulmonary aspiration of gastric contents. Careful patient selection and excellent technical skills are necessary for successful use of these devices. PMID:24891199

  3. Does the use of primary continuous positive airway pressure reduce the need for intubation and mechanical ventilation in infants ≤32 weeks’ gestation?

    PubMed Central

    Yee, Wendy H; Scotland, Jeanne; Pham, Yung; Finch, Robert

    2011-01-01

    BACKGROUND: Ventilator-induced lung injury is a recognized risk factor for bronchopulmonary dysplasia. OBJECTIVE: To determine whether primary continuous positive airway pressure (CPAP), defined as CPAP without previous endotracheal intubation for any indication, can reduce the need for intubation and mechanical ventilation in infants born at ≤32 weeks’ gestational age. METHODS: The literature was reviewed using the methodology for systematic reviews for the Consensus on Resuscitation Science adapted from the American Heart Association’s International Liaison Committee on Resuscitation. RESULTS: Fourteen studies were reviewed. Eleven studies provided varying degrees of supportive evidence (level of evidence 3 to 4) that the use of primary CPAP can reduce the need for intubation and mechanical ventilation. CONCLUSION: The use of CPAP as a primary intervention and mode of respiratory support is an option for infants ≤32 weeks’ gestation, but avoidance of intubation and mechanical ventilation is more likely in mature infants >27 weeks’ gestation. PMID:23204903

  4. Differences in perceptions of the diagnosis and treatment of obstructive sleep apnea and continuous positive airway pressure therapy among adherers and nonadherers.

    PubMed

    Sawyer, Amy M; Deatrick, Janet A; Kuna, Samuel T; Weaver, Terri E

    2010-07-01

    Obstructive sleep apnea (OSA) patients' consistent use of continuous positive airway pressure (CPAP) therapy is critical to realizing improved functional outcomes and reducing untoward health risks associated with OSA. We conducted a mixed methods, concurrent, nested study to explore OSA patients' beliefs and perceptions of the diagnosis and CPAP treatment that differentiate adherent from nonadherent patients prior to and after the first week of treatment, when the pattern of CPAP use is established. Guided by social cognitive theory, themes were derived from 30 interviews conducted postdiagnosis and after 1 week of CPAP use. Directed content analysis, followed by categorization of participants as adherent/nonadherent from objectively measured CPAP use, preceded across-case analysis among 15 participants with severe OSA. Beliefs and perceptions that differed between adherers and nonadherers included OSA risk perception, symptom recognition, self-efficacy, outcome expectations, treatment goals, and treatment facilitators/ barriers. Our findings suggest opportunities for developing and testing tailored interventions to promote CPAP use. PMID:20354236

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

    PubMed

    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

  6. Bilateral diaphragmatic paralysis--a rare cause of acute respiratory failure managed with nasal mask bilevel positive airway pressure (BiPAP) ventilation.

    PubMed

    Lin, M C; Liaw, M Y; Huang, C C; Chuang, M L; Tsai, Y H

    1997-08-01

    A 68 yr old woman presented with acute respiratory failure. She was suspected of having a phrenic-diaphragmatic impairment, without evidence of an intrinsic lung disease or generalized neuromuscular disorder, after 3 weeks of prolonged mechanical ventilation. A series of studies, including fluoroscopy, phrenic nerve stimulation test and diaphragmatic electromyography, was performed before the diagnosis of bilateral diaphragmatic paralysis (BDP) was confirmed. The patient was successfully weaned from the conventional mechanical ventilator, and was placed on nasal mask bi-level positive airway pressure (BiPAP) ventilation. A high degree of clinical suspicion of bilateral diaphragmatic paralysis should always be raised in patients suffering respiratory failure without definite predisposing factors. Weaning with noninvasive nasal mask ventilation should be tried first instead of direct tracheostomy. PMID:9272940

  7. Efficacy of Bilevel-auto Treatment in Patients with Obstructive Sleep Apnea Not Responsive to or Intolerant of Continuous Positive Airway Pressure Ventilation

    PubMed Central

    Carlucci, Annalisa; Ceriana, Piero; Mancini, Marco; Cirio, Serena; Pierucci, Paola; D'Artavilla Lupo, Nadia; Gadaleta, Felice; Morrone, Elisa; Fanfulla, Francesco

    2015-01-01

    Background: Ventilation with continuous positive airway pressure (CPAP) is the gold standard therapy for obstructive sleep apnea (OSA). However, it was recently suggested that a novel mode of ventilation, Bilevel-auto, could be equally effective in treating patients unable to tolerate CPAP. The aim of this study was to investigate the ability of Bilevel-auto to treat OSA patients whose nocturnal ventilatory disturbances are not completely corrected by CPAP. Methods: We enrolled 66 consecutive OSA patients, not responsive to (group A) or intolerant of (group B) CPAP treatment, after a full night of manual CPAP titration in a laboratory. Full polysomnography data and daytime sleepiness score were compared for each group in the three different conditions: basal, during CPAP, and during Bilevel-auto. Results: The apnea-hypopnea index decreased significantly during CPAP in both groups; however, in the group A, there was a further significant improvement during Bilevel-auto. The same trend was observed for oxygenation indices, while the distribution and the efficiency of sleep did not differ following the switch from CPAP to Bilevel-auto. Conclusions: This study confirmed the role of Bilevel-auto as an effective therapeutic alternative to CPAP in patients intolerant of this latter mode of ventilation. Moreover, extending the use of Bilevel-auto to those OSA patients not responsive to CPAP, we showed a significantly better correction of nocturnal respiratory disturbances. Citation: Carlucci A, Ceriana P, Mancini M, Cirio S, Pierucci P, D'Artavilla Lupo N, Gadaleta F, Morrone E, Fanfulla F. Efficacy of Bilevel-auto treatment in patients with obstructive sleep apnea not responsive to or intolerant of continuous positive airway pressure ventilation. J Clin Sleep Med 2015;11(9):981–985. PMID:25902825

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

    PubMed

    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

  9. Effectiveness of flow inflating device in providing Continuous Positive Airway Pressure for critically ill children in limited-resource settings: A prospective observational study

    PubMed Central

    Anitha, G. Fatima Shirly; Velmurugan, Lakshmi; Sangareddi, Shanthi; Nedunchelian, Krishnamurthy; Selvaraj, Vinoth

    2016-01-01

    Background and Aims: Noninvasive ventilation (NIV) is an emerging popular concept, which includes bi-level positive airway pressure or continuous positive airway pressure (CPAP). In settings with scarce resources for NIV machines, CPAP can be provided through various indigenous means and one such mode is flow inflating device - Jackson-Rees circuit (JR)/Bain circuit. The study analyses the epidemiology, various clinical indications, predictors of CPAP failure, and stresses the usefulness of flow inflating device as an indigenous way of providing CPAP. Methods: A prospective observational study was undertaken in the critical care unit of a Government Tertiary Care Hospital, from November 2013 to September 2014. All children who required CPAP in the age group 1 month to 12 years of both sexes were included in this study. They were started on indigenous CPAP through flow inflating device on clinical grounds based on the pediatric assessment triangle, and the duration and outcome were analyzed. Results: This study population included 214 children. CPAP through flow inflating device was successful in 89.7% of cases, of which bronchiolitis accounted for 98.3%. A prolonged duration of CPAP support of >96 h was required in pneumonia. CPAP failure was noted in 10.3% of cases, the major risk factors being children <1 year and pneumonia with septic shock. Conclusion: We conclude that flow inflating devices - JR/Bain circuit are effective as an indigenous CPAP in limited resource settings. Despite its benefits, CPAP is not a substitute for invasive ventilation, as when the need for intubation arises timely intervention is needed.

  10. Continuous Positive Airway Pressure Reduces Risk of Motor Vehicle Crash among Drivers with Obstructive Sleep Apnea: Systematic Review and Meta-analysis

    PubMed Central

    Tregear, Stephen; Reston, James; Schoelles, Karen; Phillips, Barbara

    2010-01-01

    Context: Obstructive sleep apnea (OSA) is associated with an increased risk of motor vehicle crash. Objective: We performed a systematic review of the literature concerning the impact of continuous positive airway pressure (CPAP) treatment on motor vehicle crash risk among drivers with OSA. The primary objective was to determine whether CPAP use could reduce the risk of motor vehicle crash among drivers with OSA. A secondary objective involved determining the time on treatment required for CPAP to improve driver safety. Data Sources: We searched seven electronic databases (MEDLINE, PubMed (PreMEDLINE), EMBASE, PsycINFO, CINAHL, TRIS, and the Cochrane library) and the reference lists of all obtained articles. Study Selection: We included studies (before-after, case-control, or cohort) that addressed the stated objectives. We evaluated the quality of each study and the interplay between the quality, quantity, robustness, and consistency of the evidence. We also tested for publication bias. Data Extraction: Data were extracted by two independent analysts. When appropriate, data were combined in a fixed or random effects meta-analysis. Results: A meta-analysis of 9 observational studies examining crash risk of drivers with OSA pre- vs. post-CPAP found a significant risk reduction following treatment (risk ratio = 0.278, 95% CI: 0.22 to 0.35; P < 0.001). Although crash data are not available to assess the time course of change, daytime sleepiness improves significantly following a single night of treatment, and simulated driving performance improves significantly within 2 to 7 days of CPAP treatment. Conclusions: Observational studies indicate that CPAP reduces motor vehicle crash risk among drivers with OSA. Citation: Tregear S; Reston J; Schoelles K; Phillips B. Continuous positive airway pressure reduces risk of motor vehicle crash among drivers with obstructive sleep apnea. SLEEP 2010;33(10):1373-1380. PMID:21061860

  11. Effect of Early Intervention With Positive Airway Pressure Therapy for Sleep Disordered Breathing on Six-Month Readmission Rates in Hospitalized Patients With Heart Failure.

    PubMed

    Sharma, Sunil; Mather, Paul; Gupta, Ankit; Reeves, Gordon; Rubin, Sharon; Bonita, Raphael; Chowdhury, Anindita; Malloy, Raymond; Willes, Leslee; Whellan, David

    2016-03-15

    Rehospitalization for congestive heart failure (CHF) is high within 6 months of discharge. Sleep disordered breathing (SDB) is common and underdiagnosed condition in patients with CHF. We hypothesized that early recognition and treatment of SDB in hospitalized patients with CHF will reduce hospital readmissions and emergency room visits. Patients admitted for CHF underwent overnight polysomnography within 4 weeks of discharge. Patients diagnosed with SDB were provided therapy with positive airway pressure therapy. Patients were identified as having good compliance if the device use was for a minimum of 4 hours 70% of the time for a minimum of 4 weeks during the first 3 months of therapy. Hospital admissions for 6 months before therapy were compared with readmission within 6 months after therapy in patients with good and poor compliance. A total of 70 patients were diagnosed with SDB after discharge. Of the 70 patients, 37 (53%) were compliant with positive airway pressure therapy. Compliant patients were more likely to be older (64 ± 12 vs 58 ± 11 years) and women (54% vs 33%) and less likely to be patient with diabetes (40% vs 67%) versus noncompliant patients. Although both groups experienced a decrease in total readmissions, compliant patients had a significant reduction (mean ± SE: -1.5 ± 0.2 clinical events vs -0.2 ± 0.3; p <0.0001). In this single-center analysis, identification and treatment of SDB in admitted patients with CHF with SDB is associated with reduced readmissions over 6 months after discharge. Adherence to the treatment was associated with a greater reduction in clinical events. PMID:26830259

  12. Effects of Armodafinil on Simulated Driving and Self-Report Measures in Obstructive Sleep Apnea Patients prior to Treatment with Continuous Positive Airway Pressure

    PubMed Central

    Kay, Gary G.; Feldman, Neil

    2013-01-01

    Study Objectives: Obstructive sleep apnea (OSA) has been associated with an increased risk of motor vehicle crashes. This driving risk can be reduced (≥ 50%) by treatment with continuous positive airway pressure (CPAP). However residual excessive daytime sleepiness (EDS) can persist for some patients who regularly use CPAP. The current study was designed to assess the effect of armodafinil on simulated driving performance and subsequent CPAP treatment compliance in newly diagnosed OSA patients with EDS during a 2-week “waiting period” prior to initiation of CPAP. Methods: Sixty-nine newly diagnosed OSA patients, awaiting CPAP therapy, were randomized (1:1) to placebo or armodafinil (150 mg/day) treatment. Simulated driving tests and self-report measures were completed at baseline, after 2 weeks of drug treatment, and following 6 weeks of CPAP treatment. CPAP compliance was evaluated at the end of 6 weeks of CPAP. Results: Compared to placebo, armodafinil improved simulated driving safety performance in OSA patients awaiting CPAP therapy (p = 0.03). Improvement was seen in lane position deviation (p = 0.002) and number of lane excursions (p = 0.02). Improvement was also observed on measures of sleepiness using the Epworth Sleepiness Scale (ESS) and sleep related quality of life. Following 6 weeks of CPAP, there was also significant improvement observed on multiple measures of simulated driving performance. CPAP compliance did not differ between armodafinil-treated and placebo-treated patients (p = 0.80). Conclusions: Armodafinil was found to improve simulated driving performance in OSA patients with EDS prior to initiation of CPAP. Treatment with armodafinil showed no effect on subsequent CPAP compliance. Citation: Kay GG; Feldman N. Effects of armodafinil on simulated driving and self-report measures in obstructive sleep apnea patients prior to treatment with continuous positive airway pressure. J Clin Sleep Med 2013;9(5):445-454. PMID:23674935

  13. A functional PCA model for the study of time series of pressure maps.

    PubMed

    Chicote, Juan C; Durá, Juan V; Belda, Juan M; Poveda, Rakel

    2013-04-01

    Principal component analysis and functional regression are combined in a model to analyze a time series of pressure maps. The model is tested measuring the pressures over a chair seat while a subject performs a combination of simple movements. A sampling rate of 3 Hz is adequate for applying the model in sitting postures. The model is able to detect patterns of movement over time, although more variables are necessary if the movements produce similar pressure distributions. PMID:23645485

  14. Combining COMSOL modeling with acoustic pressure maps to design sono-reactors.

    PubMed

    Wei, Zongsu; Weavers, Linda K

    2016-07-01

    Scaled-up and economically viable sonochemical systems are critical for increased use of ultrasound in environmental and chemical processing applications. In this study, computational simulations and acoustic pressure maps were used to design a larger-scale sono-reactor containing a multi-stepped ultrasonic horn. Simulations in COMSOL Multiphysics showed ultrasonic waves emitted from the horn neck and tip, generating multiple regions of high acoustic pressure. The volume of these regions surrounding the horn neck were larger compared with those below the horn tip. The simulated acoustic field was verified by acoustic pressure contour maps generated from hydrophone measurements in a plexiglass box filled with water. These acoustic pressure contour maps revealed an asymmetric and discrete distribution of acoustic pressure due to acoustic cavitation, wave interaction, and water movement by ultrasonic irradiation. The acoustic pressure contour maps were consistent with simulation results in terms of the effective scale of cavitation zones (∼ 10 cm and <5 cm above and below horn tip, respectively). With the mapped acoustic field and identified cavitation location, a cylindrically-shaped sono-reactor with a conical bottom was designed to evaluate the treatment capacity (∼ 5 L) for the multi-stepped horn using COMSOL simulations. In this study, verification of simulation results with experiments demonstrates that coupling of COMSOL simulations with hydrophone measurements is a simple, effective and reliable scientific method to evaluate reactor designs of ultrasonic systems. PMID:26964976

  15. Comparing the Laryngeal Mask Airway, Cobra Perilaryngeal Airway and Face Mask in Children Airway Management

    PubMed Central

    Tekin, Beyza; Hatipoğlu, Zehra; Türktan, Mediha; Özcengiz, Dilek

    2016-01-01

    Objective We compared the effects of the laryngeal mask airway (LMA), face mask and Cobra perilaryngeal airway (PLA) in the airway management of spontaneously breathing paediatric patients undergoing elective inguinal surgery. Methods In this study, 90 cases of 1–14-year-old children undergoing elective inguinal surgery were scheduled. The patients were randomly divided into three groups. Anaesthesia was provided with sevoflurane and 50%–50% nitrous oxide and oxygen. After providing an adequate depth of anaesthesia, supraglottic airway devices were inserted in the group I and II patients. The duration and number of insertion, haemodynamic parameters, plateau and peak inspiratory pressure and positive end-expiratory pressure of the patients were recorded preoperatively, after induction and at 5, 10, 15 and 30 min peroperatively. Results There were no statistical differences between the groups in terms of haemodynamic parameters (p>0.05). In group II, instrumentation success was higher and instrumentation time was shorter than group II. The positive end-expiratory pressure and plateau and peak inspiratory pressure values were statistically lower in group II (p<0.05). Conclusion We concluded that for airway safety and to avoid possible complications, LMA and Cobra PLA could be alternatives to face mask and that the Cobra PLA provided lower airway pressure and had a faster and more easy placement than LMA. PMID:27366563

  16. Mapping change in human pressure globally on land and within protected areas.

    PubMed

    Geldmann, Jonas; Joppa, Lucas N; Burgess, Neil D

    2014-12-01

    It is widely accepted that the main driver of the observed decline in biological diversity is increasing human pressure on Earth's ecosystems. However, the spatial patterns of change in human pressure and their relation to conservation efforts are less well known. We developed a spatially and temporally explicit map of global change in human pressure over 2 decades between 1990 and 2010 at a resolution of 10 km(2) . We evaluated 22 spatial data sets representing different components of human pressure and used them to compile a temporal human pressure index (THPI) based on 3 data sets: human population density, land transformation, and electrical power infrastructure. We investigated how the THPI within protected areas was correlated to International Union for Conservation of Nature (IUCN) management categories and the human development index (HDI) and how the THPI was correlated to cumulative pressure on the basis of the original human footprint index. Since the early 1990s, human pressure increased 64% of the terrestrial areas; the largest increases were in Southeast Asia. Protected areas also exhibited overall increases in human pressure, the degree of which varied with location and IUCN management category. Only wilderness areas and natural monuments (management categories Ib and III) exhibited decreases in pressure. Protected areas not assigned any category exhibited the greatest increases. High HDI values correlated with greater reductions in pressure across protected areas, while increasing age of the protected area correlated with increases in pressure. Our analysis is an initial step toward mapping changes in human pressure on the natural world over time. That only 3 data sets could be included in our spatio-temporal global pressure map highlights the challenge to measuring pressure changes over time. PMID:25052712

  17. A High-Value, Low-Cost Bubble Continuous Positive Airway Pressure System for Low-Resource Settings: Technical Assessment and Initial Case Reports

    PubMed Central

    Brown, Jocelyn; Machen, Heather; Kawaza, Kondwani; Mwanza, Zondiwe; Iniguez, Suzanne; Lang, Hans; Gest, Alfred; Kennedy, Neil; Miros, Robert; Richards-Kortum, Rebecca; Molyneux, Elizabeth; Oden, Maria

    2013-01-01

    Acute respiratory infections are the leading cause of global child mortality. In the developing world, nasal oxygen therapy is often the only treatment option for babies who are suffering from respiratory distress. Without the added pressure of bubble Continuous Positive Airway Pressure (bCPAP) which helps maintain alveoli open, babies struggle to breathe and can suffer serious complications, and frequently death. A stand-alone bCPAP device can cost $6,000, too expensive for most developing world hospitals. Here, we describe the design and technical evaluation of a new, rugged bCPAP system that can be made in small volume for a cost-of-goods of approximately $350. Moreover, because of its simple design—consumer-grade pumps, medical tubing, and regulators—it requires only the simple replacement of a <$1 diaphragm approximately every 2 years for maintenance. The low-cost bCPAP device delivers pressure and flow equivalent to those of a reference bCPAP system used in the developed world. We describe the initial clinical cases of a child with bronchiolitis and a neonate with respiratory distress who were treated successfully with the new bCPAP device. PMID:23372661

  18. Particle-based optical pressure sensors for 3D pressure mapping.

    PubMed

    Banerjee, Niladri; Xie, Yan; Chalaseni, Sandeep; Mastrangelo, Carlos H

    2015-10-01

    This paper presents particle-based optical pressure sensors for in-flow pressure sensing, especially for microfluidic environments. Three generations of pressure sensitive particles have been developed- flat planar particles, particles with integrated retroreflectors and spherical microballoon particles. The first two versions suffer from pressure measurement dependence on particles orientation in 3D space and angle of interrogation. The third generation of microspherical particles with spherical symmetry solves these problems making particle-based manometry in microfluidic environment a viable and efficient methodology. Static and dynamic pressure measurements have been performed in liquid medium for long periods of time in a pressure range of atmospheric to 40 psi. Spherical particles with radius of 12 μm and balloon-wall thickness of 0.5 μm are effective for more than 5 h in this pressure range with an error of less than 5%. PMID:26342493

  19. Mapping physiological G protein-coupled receptor signaling pathways reveals a role for receptor phosphorylation in airway contraction

    PubMed Central

    Bradley, Sophie J.; Iglesias, Max Maza; Kong, Kok Choi; Butcher, Adrian J.; Plouffe, Bianca; Goupil, Eugénie; Bourgognon, Julie-Myrtille; Macedo-Hatch, Timothy; LeGouill, Christian; Russell, Kirsty; Laporte, Stéphane A.; König, Gabriele M.; Kostenis, Evi; Bouvier, Michel; Chung, Kian Fan; Amrani, Yassine; Tobin, Andrew B.

    2016-01-01

    G protein-coupled receptors (GPCRs) are known to initiate a plethora of signaling pathways in vitro. However, it is unclear which of these pathways are engaged to mediate physiological responses. Here, we examine the distinct roles of Gq/11-dependent signaling and receptor phosphorylation-dependent signaling in bronchial airway contraction and lung function regulated through the M3-muscarinic acetylcholine receptor (M3-mAChR). By using a genetically engineered mouse expressing a G protein-biased M3-mAChR mutant, we reveal the first evidence, to our knowledge, of a role for M3-mAChR phosphorylation in bronchial smooth muscle contraction in health and in a disease state with relevance to human asthma. Furthermore, this mouse model can be used to distinguish the physiological responses that are regulated by M3-mAChR phosphorylation (which include control of lung function) from those responses that are downstream of G protein signaling. In this way, we present an approach by which to predict the physiological/therapeutic outcome of M3-mAChR–biased ligands with important implications for drug discovery. PMID:27071102

  20. SU-C-BRA-07: Virtual Bronchoscopy-Guided IMRT Planning for Mapping and Avoiding Radiation Injury to the Airway Tree in Lung SAbR

    SciTech Connect

    Sawant, A; Modiri, A; Bland, R; Yan, Y; Ahn, C; Timmerman, R

    2015-06-15

    Purpose: Post-treatment radiation injury to central and peripheral airways is a potentially important, yet under-investigated determinant of toxicity in lung stereotactic ablative radiotherapy (SAbR). We integrate virtual bronchoscopy technology into the radiotherapy planning process to spatially map and quantify the radiosensitivity of bronchial segments, and propose novel IMRT planning that limits airway dose through non-isotropic intermediate- and low-dose spillage. Methods: Pre- and ∼8.5 months post-SAbR diagnostic-quality CT scans were retrospectively collected from six NSCLC patients (50–60Gy in 3–5 fractions). From each scan, ∼5 branching levels of the bronchial tree were segmented using LungPoint, a virtual bronchoscopic navigation system. The pre-SAbR CT and the segmented bronchial tree were imported into the Eclipse treatment planning system and deformably registered to the planning CT. The five-fraction equivalent dose from the clinically-delivered plan was calculated for each segment using the Universal Survival Curve model. The pre- and post-SAbR CTs were used to evaluate radiation-induced segmental collapse. Two of six patients exhibited significant segmental collapse with associated atelectasis and fibrosis, and were re-planned using IMRT. Results: Multivariate stepwise logistic regression over six patients (81 segments) showed that D0.01cc (minimum point dose within the 0.01cc receiving highest dose) was a significant independent factor associated with collapse (odds-ratio=1.17, p=0.010). The D0.01cc threshold for collapse was 57Gy, above which, collapse rate was 45%. In the two patients exhibiting segmental collapse, 22 out of 32 segments showed D0.01cc >57Gy. IMRT re-planning reduced D0.01cc below 57Gy in 15 of the 22 segments (68%) while simultaneously achieving the original clinical plan objectives for PTV coverage and OAR-sparing. Conclusion: Our results indicate that the administration of lung SAbR can Result in significant injury to

  1. A Randomized Crossover Trial of the Effect of a Novel Method of Pressure Control (SensAwake) in Automatic Continuous Positive Airway Pressure Therapy to Treat Sleep Disordered Breathing

    PubMed Central

    Dungan, George C.; Marshall, Nathaniel S.; Hoyos, Camilla M.; Yee, Brendon J.; Grunstein, Ronald R.

    2011-01-01

    Objectives: To study the acute effect of the new SensAwake CPAP modality (reducing pressure on awakenings) on wake after sleep onset (WASO) and other polysomnographic measures in patients with obstructive sleep apnea (OSA). Study Design: Randomized crossover trial comparing an automatic continuous positive airway pressure device (AutoCPAP) with and without SensAwake on sleep architecture. CPAP naive patients received each therapy for a single night in the laboratory with at least 1-week washout. Both patients' and technicians' subjective satisfaction was assessed. Pressure data measured and stored by the AutoCPAP device were also analyzed. Results: OSA was controlled adequately by both modes (SensAwake ON apnea hypopnea index ± SD, AHI = 5.3 ± 5.6/h vs. SensAwake OFF = 5.4 ± 5.8, p = 0.9) in the 42 patients who completed the protocol. Mean and 90% pressures were significantly lower with SensAwake (mean ON = 6.9 ± 1.9 vs. OFF = 7.7 ± 2.5 cm H2O, p < 0.05; 90% pressure ON = 9.6 ± 2.7 vs. OFF = 10.6 ± 2.7 cm H2O, p < 0.02). SensAwake did not improve WASO (ON = 74 ± 54 min vs. OFF = 78 ± 51 min, p = 0.6). There were no differences in other sleep architecture measures or patient satisfaction between the 2 modalities. AutoCPAP-measured AHI closely approximated PSG-derived (ROC AUC = 0.81 [95% CI 0.71-0.92], p = 0.0001). Conclusions: SensAwake provides similar control of the AHI to the standard AutoCPAP mode but does so at lower mean and 90% pressures. However, no measure of sleep architecture was significantly improved by the SensAwake mode during this initial acute exposure. The internal AutoCPAP AHI detection and calculation was similar to PSG-derived AHI measures. Longer term studies are needed to evaluate any long-term influence of SensAwake on WASO. Citation: Dungan GC; Marshall NS; Hoyos CM; Yee BJ; Grunstein RR. A randomized crossover trial of the effect of a novel method of pressure control (SensAwake) in automatic continuous positive airway pressure

  2. Measurement of dynamic strength at high pressures using magnetically applied pressure-shear (MAPS) on the Sandia Z accelerator

    NASA Astrophysics Data System (ADS)

    Alexander, C.; Haill, T.; Dalton, D.; Rovang, D.; Lamppa, D.

    2013-06-01

    The recently developed magnetically applied pressure-shear (MAPS) technique used to measure dynamic material strength at high pressures on magneto-hydrodynamic (MHD) drive pulsed power platforms has been implemented on the Sandia Z accelerator. MAPS relies on an external magnetic field normal to the plane of the MHD drive current to directly induce a shear stress wave in addition to the usual longitudinal stress wave. This shear wave is used to directly probe the strength of a sample. By implementing this technique on Z, far greater pressures can be attained than were previously available using other MHD facilities. In addition, the use of isentropic compression will limit sample heating allowing the measurement to be made at a much lower temperature than under shock compression. Details of the experimental approach, including design considerations and analysis of the results, will be presented along with the results of Z experiments measuring the strength of tantalum at pressures up to 50 GPa, a five-fold increase in pressure over previous results using this technique. Sandia National Labs is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  3. 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

    PubMed Central

    Muellenbach, Ralf M; Kredel, Markus; Zollhoefer, Bernd; Wunder, Christian; Roewer, Norbert; Brederlau, Joerg

    2006-01-01

    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 < 0.001) and PaCO2-reduction (HFOV: 42 ± 5 vs. PCV: 62 ± 13 and TAli: 55 ± 9; p < 0.001) during HFOV compared to lung injury and PCV. Augmentation of mPaw improved gas exchange and pulmonary shunt fraction in both groups, but at a significant lower mPaw in the HFOV treated animals. Cardiac output was continuously deteriorating during the recruitment manoeuvre in both study groups (HFOV: TAli: 6.1 ± 1 vs. T75: 3.4 ± 0.4; PCV: TAli: 6.7 ± 2.4 vs. T75: 4 ± 0.5; p < 0.001). 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

  4. Automated pressure map segmentation for quantifying phalangeal kinetics during cylindrical gripping.

    PubMed

    Sinsel, Erik W; Gloekler, Daniel S; Wimer, Bryan M; Warren, Christopher M; Wu, John Z; Buczek, Frank L

    2016-02-01

    Inverse dynamics models used to investigate musculoskeletal disorders associated with handle gripping require accurate phalangeal kinetics. Cylindrical handles wrapped with pressure film grids have been used in studies of gripping kinetics. We present a method fusing six degree-of-freedom hand kinematics and a kinematic calibration of a cylinder-wrapped pressure film. Phalanges are modeled as conic frusta and projected onto the pressure grid, automatically segmenting the pressure map into regions of interest (ROIs). To demonstrate the method, segmented pressure maps are presented from two subjects with substantially different hand length and body mass, gripping cylinders 50 and 70 mm in diameter. For each ROI, surface-normal force vectors were summed to create a reaction force vector and center of pressure location. Phalangeal force magnitudes for a data sample were similar to that reported in previous studies. To evaluate our method, a surrogate was designed for each handle such that when modeled as a phalanx it would generate a ROI around the cells under its supports; the classification F-score was above 0.95 for both handles. Both the human subject results and the surrogate evaluation suggest that the approach can be used to automatically segment the pressure map for quantifying phalangeal kinetics of the fingers during cylindrical gripping. PMID:26709291

  5. Evaluation of effect of continuous positive airway pressure during cardiopulmonary bypass on cardiac de-airing after open heart surgery in randomized clinical trial

    PubMed Central

    Mansour, Mojtaba; Massodnia, Nasim; Mirdehghan, Abolghasem; Bigdelian, Hamid; Massoumi, Gholamreza; Alavi, Zeinab Rafieipour

    2014-01-01

    Background: Cardiac and pulmonary veins de-airing are of the most important steps during open heart surgery. This study evaluates the effect of continuous positive airway pressure (CPAP) on air trapping in pulmonary veins and on quality of de-airing procedure. Materials and Methods: This randomized prospective double blind clinical trial conducted on 40 patients. In the control group: During cardiopulmonary bypass (CPB), the ventilator was turned off and adjustable pressure limit (APL) valve was placed in SPONT position. In CPAP group: During CPB, after turning the ventilator off, the flow of oxygen flow was maintained at the rate of 0.5 L/min and the APL valve was placed in MAN position on 20 mbar. During cardiopulmonary bypass (CPB) weaning, the patients were observed for air bubbles in left atrium by using transesophageal echocardiography. Results: The mean de-airing time after the start of mechanical ventilation in CPAP group (n = 20) was significantly lower than the control group (n = 20) (P = 0.0001). The mean time of the left atrium air bubbles occupation as mild (P = 0.004), moderate (P = 0.0001) and severe (P = 0.015) grading was significantly lower in CPAP group. Conclusions: By CPAP at 20 mbar during CPB in open heart surgery, de-airing process can be down in better quality and in significantly shorter time. PMID:24949307

  6. 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.

    PubMed

    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

  7. Nonlinear systems dynamics in cardiovascular physiology: The heart rate delay map and lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Hooker, John C.

    1990-01-01

    A preliminary study of the applicability of nonlinear dynamic systems analysis techniques to low body negative pressure (LBNP) studies. In particular, the applicability of the heart rate delay map is investigated. It is suggested that the heart rate delay map has potential as a supplemental tool in the assessment of subject performance in LBNP tests and possibly in the determination of susceptibility to cardiovascular deconditioning with spaceflight.

  8. Total airway reconstruction.

    PubMed

    Connor, Matthew P; Barrera, Jose E; Eller, Robert; McCusker, Scott; O'Connor, Peter

    2013-02-01

    We present a case of obstructive sleep apnea (OSA) that required multilevel surgical correction of the airway and literature review and discuss the role supraglottic laryngeal collapse can have in OSA. A 34-year-old man presented to a tertiary otolaryngology clinic for treatment of OSA. He previously had nasal and palate surgeries and a Repose tongue suspension. His residual apnea hypopnea index (AHI) was 67. He had a dysphonia associated with a true vocal cord paralysis following resection of a benign neck mass in childhood. He also complained of inspiratory stridor with exercise and intolerance to continuous positive airway pressure. Physical examination revealed craniofacial hypoplasia, full base of tongue, and residual nasal airway obstruction. On laryngoscopy, the paretic aryepiglottic fold arytenoid complex prolapsed into the laryngeal inlet with each breath. This was more pronounced with greater respiratory effort. Surgical correction required a series of operations including awake tracheostomy, supraglottoplasty, midline glossectomy, genial tubercle advancement, maxillomandibular advancement, and reconstructive rhinoplasty. His final AHI was 1.9. Our patient's supraglottic laryngeal collapse constituted an area of obstruction not typically evaluated in OSA surgery. In conjunction with treating nasal, palatal, and hypopharyngeal subsites, our patient's supraglottoplasty represented a key component of his success. This case illustrates the need to evaluate the entire upper airway in a complicated case of OSA. PMID:22965285

  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

    PubMed Central

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

    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 undertaken 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. PMID:26315086

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

    PubMed Central

    Badiee, Zohreh; Naseri, Fatemeh; Sadeghnia, Alireza

    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 entered the study. Infants were randomly assigned to the very early CPAP (initiated 5 min after birth) or to the late CPAP (initiated 30 min after birth) treatment groups. The primary outcomes were need for intubation and mechanical ventilation during the first 48 h after birth and secondary outcomes were death, pneumothorax, intraventricular hemorrhage, duration of mechanical ventilation and bronchopulmonary dysplasia. Results: There were no significant differences between the two groups with regard to mortality rate, bronchopulmonary dysplasia and patent ductus arteriosus. The need for surfactant administration was significantly reduced in the early CPAP group (P = 0.04). Infants in the early CPAP group less frequently required intubation and mechanical ventilation. Conclusions: Early n CPAP is more effective than late n CPAP for the treatment of respiratory distress syndrome. In addition, the early use of n CPAP would reduce the need for some invasive procedures such as intubation and mechanical ventilation. PMID:23930249

  11. Impact of the type of mask on the effectiveness of and adherence to continuous positive airway pressure treatment for obstructive sleep apnea*

    PubMed Central

    de Andrade, Rafaela Garcia Santos; Piccin, Vivien Schmeling; Nascimento, Juliana Araújo; Viana, Fernanda Madeiro Leite; Genta, Pedro Rodrigues; Lorenzi-Filho, Geraldo

    2014-01-01

    Continuous positive airway pressure (CPAP) is the gold standard for the treatment of obstructive sleep apnea (OSA). Although CPAP was originally applied with a nasal mask, various interfaces are currently available. This study reviews theoretical concepts and questions the premise that all types of interfaces produce similar results. We revised the evidence in the literature about the impact that the type of CPAP interface has on the effectiveness of and adherence to OSA treatment. We searched the PubMed database using the search terms "CPAP", "mask", and "obstructive sleep apnea". Although we identified 91 studies, only 12 described the impact of the type of CPAP interface on treatment effectiveness (n = 6) or adherence (n = 6). Despite conflicting results, we found no consistent evidence that nasal pillows and oral masks alter OSA treatment effectiveness or adherence. In contrast, most studies showed that oronasal masks are less effective and are more often associated with lower adherence and higher CPAP abandonment than are nasal masks. We concluded that oronasal masks can compromise CPAP OSA treatment adherence and effectiveness. Further studies are needed in order to understand the exact mechanisms involved in this effect. PMID:25610507

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

    PubMed

    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

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

    PubMed

    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 < 0.001), CPAP -25.4 (p < 0.001)). In direct comparisons mean AHI and Epworth sleepiness scale score were lower (7.0/hr (p < 0.001) and 0.67 (p = 0.093) respectively) for CPAP. There were no CPAP vs. MAD trials in mild OSAH but in comparisons with CM, MAD and CPAP reduced ESS similarly (MAD 2.01 (p < 0.001); CPAP 1.23 (p = 0.012). Both MAD and CPAP are clinically 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

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

    PubMed Central

    Chen, Xiaofen; Chen, Weiting; Hu, Weijie; Huang, Kui; Huang, Jing; Zhou, Yu

    2015-01-01

    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. PMID:26648703

  15. Upper airway resistance syndrome.

    PubMed

    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

  16. Acute effects of different levels of continuous positive airway pressure on cardiac autonomic modulation in chronic heart failure and chronic obstructive pulmonary disease

    PubMed Central

    Reis, Michel S.; Sampaio, Luciana M.M.; Lacerda, Diego; De Oliveira, Luis V.F.; Pereira, Guilherme B.; Pantoni, Camila B.F.; Thommazo, Luciana Di; Catai, Aparecida M.

    2010-01-01

    Introduction Non-invasive ventilation may improve autonomic modulation and ventilatory parameters in severely disabled patients. The aim of the present study was to evaluate the physiological influence of acute treatment with different levels of continuous positive airway pressure (CPAP) on the autonomic balance of heart and respiratory responses in patients with stable chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF). Materials and methods A COPD group (n = 10), CHF group (n = 8) and healthy subjects (n = 10) were evaluated. The participants were randomized to receive three different levels of CPAP on the same day: sham ventilation (Sham), 5 cmH20 (CPAP5) and 10 cmH20 (CPAP10) for 10 min. Respiratory rate, end tidal carbon dioxide (ETCO2), peripheral oxygen saturation (SpO2), heart rate (HR), blood pressure and heart rate variability in the time and frequency domains were measured during spontaneous breathing and under the sham, CPAP5 and CPAP10 conditions. Results All groups experienced a reduction in ETCO2 values during treatment with CPAP (p < 0.05). CPAP increased SpO2 and HR in the COPD group (p < 0.05). The COPD group also had lower RMSSD values during treatment with different levels of CPAP when compared to the control group (p < 0.05). In the CHF group, CPAP5 and CPAP10 increased the SDNN value (p < 0.05). CPAP10 reduced the SDNN value in the COPD group (p < 0.05). Conclusion The findings suggest that CPAP may cause improvements in the neural control of heart rate in patients with stable COPD and CHF. For each patient, the “best CPAP level” should be defined as the best respiratory response and autonomic balance. PMID:22419931

  17. Emergency airway puncture

    MedlinePlus

    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 ...

  18. The use of the BiPAP biphasic positive airway pressure system in acute spinal cord injury.

    PubMed

    Tromans, A M; Mecci, M; Barrett, F H; Ward, T A; Grundy, D J

    1998-07-01

    In recent years there has been increasing demand on our Intensive Care Unit (ICU) facilities, mainly due to improved resuscitation techniques in the pre-hospital management of spinal cord injury (SCI). This has resulted in an increasing number of high tetraplegic and paraplegic patients with respiratory problems who have survived the initial injury, but have subsequently required ventilatory support, often for several weeks. In view of the continuing pressure on ICU beds and a consequent need for alternative means of providing ventilatory support within the spinal centre rather than within the ICU setting, there was a requirement to provide a simple means of ventilatory support suitable for use within the ward setting. Ventilatory assistance using BiPAP appeared to fulfil these criteria, enabling patients to be managed at reduced cost. We present our experience using this system in 28 acute SCI patients over a 4 year period. PMID:9670384

  19. Effective compliance during the first 3 months of continuous positive airway pressure. A European prospective study of 121 patients.

    PubMed

    Pépin, J L; Krieger, J; Rodenstein, D; Cornette, A; Sforza, E; Delguste, P; Deschaux, C; Grillier, V; Lévy, P

    1999-10-01

    Effective compliance (time spent at the effective pressure) with nasal CPAP in obstructive sleep apnea has been reported to be poor. The aim of our study was to evaluate effective compliance in a large European multicenter study. One hundred twenty-one consecutive newly treated patients (initial apnea-hypopnea index [AHI] = 62.0 +/- 29. 5/h, AHI under CPAP = 6.4 +/- 8.1/h, CPAP pressure = 8.7 +/- 2.6 cm H(2)O, BMI = 33.1 +/- 6.8 kg/m(2)) were randomly allocated to a group with (MC(+)) (n = 58) or without (MC(-)) (n = 63) a control unit measuring effective compliance at 1, 2, and 3 mo, which was compared with the built-in time counter data. MC(+) data were 94 +/- 10, 98 +/- 5, and 96 +/- 9% of counter data at 1, 2, and 3 mo, respectively. Using criteria of regular use already reported in the literature (at least 4 h of nCPAP per day of use and nCPAP administered more than 70% of the days) we found 77, 82, and 79% compliant patients at 1, 2, and 3 mo, respectively, 79% of the patients meeting these criteria each month. Although there were no pulmonary functions or polysomnographic differences between the two subgroups, the compliant patients did report a greater improvement in minor symptoms. We found a close correlation between effective use of CPAP and the machine run time. The main result of our study was a higher effective compliance than previously reported, approximately 80% of the patients being regular users versus 46% in a previously published study. This may result from different technical and medical follow-up. PMID:10508797

  20. Puberty and Upper Airway Dynamics During Sleep

    PubMed Central

    Bandla, Preetam; Huang, Jingtao; Karamessinis, Laurie; Kelly, Andrea; Pepe, Michelle; Samuel, John; Brooks, Lee; Mason, Thornton. A.; Gallagher, Paul R.; Marcus, Carole L.

    2008-01-01

    Study Objectives: The upper airway compensatory response to subatmospheric pressure loading declines with age. The epidemiology of obstructive sleep apnea suggests that sex hormones play a role in modulating upper airway function. Sex hormones increase gradually during puberty, from minimally detectable to adult levels. We hypothesized that the upper airway response to subatmospheric pressure loading decreased with increasing pubertal Tanner stage in males but remained stable during puberty in females. Design: Upper airway dynamic function during sleep was measured over the course of puberty. Participants: Normal subjects of Tanner stages 1 to 5. Measurements: During sleep, maximal inspiratory airflow was measured while varying the level of nasal pressure. The slope of the upstream pressure-flow relationship (SPF) was measured. Results: The SPF correlated with age and Tanner stage. However, the relationship with Tanner stage became nonsignificant when the correlation due to the mutual association with age was removed. Females had a lower SPF than males. Conclusions: In both sexes, the upper airway compensatory response to subatmospheric pressure loading decreased with age rather than degree of pubertal development. Thus, changes in sex hormones are unlikely to be a primary modulator of upper airway function during the transition from childhood to adulthood. Although further studies of upper airway structural changes during puberty are needed, we speculate that the changes in upper airway function with age are due to the depressant effect of age on ventilatory drive, leading to a decrease in upper airway neuromotor tone. Citation: Bandla P; Huang J; Karamessinis L; Kelly A; Pepe M; Samuel J; Brooks L; Mason TA; Gallagher PR; Marcus CL. Puberty and Upper Airway Dynamics During Sleep. SLEEP 2008;31(4):534-541. PMID:18457241

  1. Blockage of upper airway

    MedlinePlus

    ... Airway obstruction - acute upper Images Throat anatomy Choking Respiratory system References Cukor J, Manno M. Pediatric respiratory emergencies: upper airway obstruction and infections. In: Marx ...

  2. [Nasal BiPAP (bilevel positive airway pressure) respiration with controlled respiratory mode in neuromuscular diseases and severe kyphoscoliosis].

    PubMed

    Netzer, N; Werner, P; Korinthenberg, R; Matthys, H

    1995-03-01

    The BiPAP-System is a useful ventilatory support for patients with severe sleep apnea and need for high inspiratory pressure. Using the BiPAP as a full ventilatory support is new due to the recent addition of a timed control modus and individual control of inspiratory time. We used the new BiPAP ST-System in one young men with Duchenne-disease, one man with heredo ataxia (Friedreich), one women with spinal muscular atrophy, one man with central sleep apnea due to brainstem infarction as well as two women and one men with severe kyphoscoliosis. All patients had a significant hypoventilation and hypoxemia at night, which was documented by polysomnography. Mechanical ventilation at night with nasal BiPAP increased the baseline oxygen saturation (SaO2) by an average of 11.9% in all seven patients. The frequency of desaturations below 90% diminished by an average of 81%. The lowest SaO2 measured increased by 28% in all seven patients combined. Rhinitis due to the dryness of the inspired air were noticed in only two patients. Two other patients needed adaptation to the customized mask. The nasal BiPAP-System using the T-mode is a useful device to support ventilation at night and thus it could replace ventilatory support by the IPPV-mode in many patients. PMID:7617604

  3. Can Continuous Positive Airway Pressure Reduce the Risk of Stroke in Obstructive Sleep Apnea Patients? A Systematic Review and Meta-Analysis

    PubMed Central

    Kim, Yeshin; Koo, Yong Seo; Lee, Hee Young; Lee, Seo-Young

    2016-01-01

    Background and Purpose Obstructive sleep apnea (OSA) has been shown to increase the risk of stroke. Although continuous positive airway pressure (CPAP) is considered the treatment of choice for OSA, whether treating OSA with CPAP reduces the risk of stroke remains unclear. We aimed to evaluate the effects of CPAP on incidence of stroke in patients with OSA. Materials and Methods We conducted a systematic review and meta-analysis of all published studies that provided the number of incident strokes in OSA patients in light of their treatment status with CPAP. Results We identified 8 relevant studies: one randomized controlled study (RCT), 5 cohort studies, and 2 studies using administrative health data. The two overlapping cohort studies in women and the elderly and the 2 studies using administrative health data had analyzed the impact of CPAP on stroke apart from cardiac events, whereas the others had focused on the overall cardiovascular events. Based on a meta-analysis of the cohort studies, treatment with CPAP was associated with a lower incidence of stroke and cardiac events with relative risks of 0.27 [0.14–0.53], and 0.54 [0.38–0.75], respectively, although this could not be reproduced in the RCT and the studies using administrative data. Conclusions Treating with CPAP in patients with OSA might decrease the risk of stroke, although there is some conflicting evidence. Such effect was more pronounced in stroke than in cardiac events. Future studies analyzing stroke apart from cardiac disease would be of interest. PMID:26731604

  4. Early Surfactant Therapy With Nasal Continuous Positive Airway Pressure or Continued Mechanical Ventilation in Very Low Birth Weight Neonates With Respiratory Distress Syndrome

    PubMed Central

    Najafian, Bita; Fakhraie, Seyed Hasan; Afjeh, Seyed Abulfazl; Kazemian, Mohammad; Shohrati, Majid; Saburi, Amin

    2014-01-01

    Background: Various strategies have been suggested for the treatment of respiratory distress syndrome (RDS). Objectives: The aim of this study was to compare the efficacies of two common methods of RDS management among neonates with low birth weight. Patients and Methods: A cohort study was conducted on 98 neonates with definite diagnosis of RDS during 2008-2009. The neonates were divided into two groups by a blinded supervisor using simple randomization (odd and even numbers). Forty-five cases in the first group were treated with intubation, surfactant therapy, extubation (INSURE method) followed by nasal continuous positive airway pressure (N.CPAP) and 53 cases in the second group underwent intubation, surfactant therapy followed by mechanical ventilation (MV). Results: Five (11.1%) cases in the first group and 23 (43%) cases in the second group expired during the study. The rates of MV dependency among cases with INSURE failure and cases in the MV group were 37% and 83%, respectively (P < 0.001). Birth weight (BW) (P = 0.017), presence of retinopathy of prematurity (P = 0.022), C/S delivery (P = 0.029) and presence of lung bleeding (P = 0.010) could significantly predict mortality in the second group, although only BW (P = 0.029) had a significant impact on the mortality rate in the first group. Moreover, BW was significantly related to the success rate in the first group (P = 0.001). Conclusions: Our findings demonstrated that INSURE plus NCPAP was more effective than the routine method (permanent intubation after surfactant prescription). In addition, the lower rates of mortality, MV dependency, duration of hospitalization, and complications were observed in cases treated with the INSURE method compared to the routine one. PMID:24910785

  5. Management of Neonatal Respiratory Distress Syndrome Employing ACoRN Respiratory Sequence Protocol versus Early Nasal Continuous Positive Airway Pressure Protocol

    PubMed Central

    Niknafs, Pedram; Faghani, Asadallah; Afjeh, Seyed-Abolfazl; Moradinazer, Mehdi; Bahman-Bijari, Bahareh

    2014-01-01

    Objective: Respiratory distress syndrome (RDS) is a common cause of respiratory distress in premature infants. This study was designed to evaluate two different RDS treatment protocols by comparing the outcomes. Methods: This study was a double center cross sectional study performed from June to December 2012. During that period, 386 neonates with RDS were hospitalized and treated according to two different therapeutic protocols so-called Acute Care of at-Risk Newborns (ACoRN) respiratory sequence protocol (group I) and Early Nasal Continuous Positive Airway Pressure (E-NCPAP) protocol (group II). The variables and main outcomes of this study were gestational age, birth weight, bronchopulmonary dysplasia (BPD), pulmonary hemorrhage (PH), intraventricular hemorrhage (IVH), air leak and mortality rate (MR). Findings : Out of 386 infants, 202 infants were in group I (male 60.4%, female 39.6%, mean gestational age 316/7 weeks, mean birth weight=1688 grams) and group II included 184 infants (male 61.4%, female 38.6%, mean gestational age 32 weeks, mean birth weight 1787 grams), P= 0.07. The ratios of BPD of group I to group II and PH of group I to group two were not significant (P=0.63 and P=0.84, respectively). Air leak ratio in group I was higher than in group II (P=0.001). Although IVH ratio in group II was higher than in group I (P=0.01), grade III and IV IVH was higher in group I (30% vs. 4.6%). In case of MR, it was higher in group I than in group II (P=0.001). Conclusion: According to the findings the incidence of air leak, grade III and IV IVH and MR was less common in E-NCPAP protocol, so it may show the effectiveness of this protocol. The authors suggest that more researches are needed for more accurate results. PMID:25793046

  6. The Efficacy of Continuous Positive Airway Pressure Therapy on Nocturia in Patients With Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

    PubMed Central

    Wang, Tao; Huang, Wei; Zong, Huantao; Zhang, Yong

    2015-01-01

    Purpose: To assess the efficacy of the continuous positive airway pressure (CPAP) on nocturia in patients with obstructive sleep apnea (OSA). Methods: A literature review was performed to identify all published clinical trials of CPAP for the treatment of nocturia. The search included the following databases: MEDLINE, Embase, and the Cochrane Controlled Trials Register. The reference lists of the retrieved studies were also investigated. Results: Five publications involving a total of 307 patients were used in the analysis, which compared the number of incidents of nocturia before and after CPAP treatment. We found that patients with OSA and nocturia who were treated with CPAP had a significant decrease in the frequency of nocturia and the volume of urine associated with it. The mean number of nocturia incidents (standardized mean difference [SMD], –2.28; 95% confidence interval [CI], –2.42 to –2.15; P<0.00001) and the associated urine volume (SMD, –183.12; 95% CI, –248.27 to –117.98; P<0.00001) indicated that CPAP was effective. Besides, the Epworth Sleepiness Scale (SMD, –5.88; 95% CI, –6.56 to –5.21; P<0.00001) and the CPAP apnea-hypopnea index (SMD, –31.57; 95% CI, –33.87 to –29.28; P<0.00001) indicated that CPAP significantly improved the quality of sleep. Conclusions: This meta-analysis indicates that CPAP maybe an effective treatment for reducing nocturia associated with OSA and improving the quality of life of such patients. PMID:26620900

  7. 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

    PubMed Central

    Valizadeh, Sousan; Hosseini, Mohammad Bagher; Asghari Jafarabadi, Mohammad; Ajoodanian, Najmeh

    2012-01-01

    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. PMID:25276695

  8. 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

    PubMed Central

    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

  9. Brachycephalic airway obstructive syndrome.

    PubMed

    Wykes, P M

    1991-06-01

    This is a complex condition, recognized primarily in brachycephalic breeds, that results in varying degrees of upper airway obstruction. The signs consist of respiratory distress, stridor, reduced exercise tolerance, and in more severe cases, cyanosis and collapse. The inherent anatomy of the brachycephalic skull contributes to the development of these signs. Such anatomic features include: a shortened and distorted nasopharynx, stenotic nares, an elongated soft palate, and everted laryngeal saccules. The increased negative pressure created in the pharyngolaryngeal region, as a result of these obstructing structures, ultimately results in distortion and collapse of the arytenoid cartilages of the larynx. PMID:1802247

  10. [Effect of changes in airway pressure and the inspiratory volume on the fluid filtration rate and pulmonary artery pressure in isolated rabbit lungs perfused with blood and acellular solution].

    PubMed

    Crespo, Astrid; Novoa, Eva; Urich, Daniela; Trejo, Humberto; Pezzulo, Alejandro; Sznajder, Jacob I; Livia, Fernández; Sánchez-de León, Roberto

    2006-12-01

    It has been reported that ventilation with large tidal volumes causes pulmonary edema in rats by the stimulation and release of proinflammatory mediators. Our objective was to determine the level at which volutrauma induced by changes in Airway Pressure (PAW) and Inspiratory Volume (VI) produce significant changes on the Fluid Filtration Rate (FFR) and Pulmonary Artery Pressure (PAP) in lungs perfused with blood (cellular groups) or with a buffer-albumin solution (acellular groups), with a Positive End Expiratory Pressure (PEEP) 0 or 2 cmH2O and to study the effect of a vasodilator with antiinflammatory properties (fenoterol) in blood-perfused groups. Three experimental groups were used: the cellular groups studied the effect of increased PAW and IV in isolated lungs perfused with blood and PEEP 0 and 2; the acellular groups studied the increased PAW and IV in isolated lungs perfused with a buffer-albumin solution and PEEP 0 and 2; The fenoterol group studied the effect of increased PAW and IV in isolated lungs perfused with blood + fenoterol and PEEP 2. The results show that an increase of FFR is produced earlier in acellular groups than in cellular ones and that the damage in cellular groups is microscopically and macroscopically inferior when compared to acellular groups. Fenoterol did not inhibit edema formation, and that PEEP 2, both in the cellular and the acellular groups, has a protective effect. We propose the possible existence of mediators with protective effects against the formation of pulmonary edema in the blood. These data suggest that volutrauma induced pulmonary edema has a predominantly traumatic origin when the lungs are perfused with blood. PMID:17176901

  11. Earthquake dynamics. Mapping pressurized volcanic fluids from induced crustal seismic velocity drops.

    PubMed

    Brenguier, F; Campillo, M; Takeda, T; Aoki, Y; Shapiro, N M; Briand, X; Emoto, K; Miyake, H

    2014-07-01

    Volcanic eruptions are caused by the release of pressure that has accumulated due to hot volcanic fluids at depth. Here, we show that the extent of the regions affected by pressurized fluids can be imaged through the measurement of their response to transient stress perturbations. We used records of seismic noise from the Japanese Hi-net seismic network to measure the crustal seismic velocity changes below volcanic regions caused by the 2011 moment magnitude (M(w)) 9.0 Tohoku-Oki earthquake. We interpret coseismic crustal seismic velocity reductions as related to the mechanical weakening of the pressurized crust by the dynamic stress associated with the seismic waves. We suggest, therefore, that mapping seismic velocity susceptibility to dynamic stress perturbations can be used for the imaging and characterization of volcanic systems. PMID:24994652

  12. Non-invasive computation of aortic pressure maps: a phantom-based study of two approaches

    NASA Astrophysics Data System (ADS)

    Delles, Michael; Schalck, Sebastian; Chassein, Yves; Müller, Tobias; Rengier, Fabian; Speidel, Stefanie; von Tengg-Kobligk, Hendrik; Kauczor, Hans-Ulrich; Dillmann, Rüdiger; Unterhinninghofen, Roland

    2014-03-01

    Patient-specific blood pressure values in the human aorta are an important parameter in the management of cardiovascular diseases. A direct measurement of these values is only possible by invasive catheterization at a limited number of measurement sites. To overcome these drawbacks, two non-invasive approaches of computing patient-specific relative aortic blood pressure maps throughout the entire aortic vessel volume are investigated by our group. The first approach uses computations from complete time-resolved, three-dimensional flow velocity fields acquired by phasecontrast magnetic resonance imaging (PC-MRI), whereas the second approach relies on computational fluid dynamics (CFD) simulations with ultrasound-based boundary conditions. A detailed evaluation of these computational methods under realistic conditions is necessary in order to investigate their overall robustness and accuracy as well as their sensitivity to certain algorithmic parameters. We present a comparative study of the two blood pressure computation methods in an experimental phantom setup, which mimics a simplified thoracic aorta. The comparative analysis includes the investigation of the impact of algorithmic parameters on the MRI-based blood pressure computation and the impact of extracting pressure maps in a voxel grid from the CFD simulations. Overall, a very good agreement between the results of the two computational approaches can be observed despite the fact that both methods used completely separate measurements as input data. Therefore, the comparative study of the presented work indicates that both non-invasive pressure computation methods show an excellent robustness and accuracy and can therefore be used for research purposes in the management of cardiovascular diseases.

  13. Simulation and analysis of Magnetically-Applied Pressure-Shear (MAPS) experiments.

    SciTech Connect

    Haill, Thomas A.; Alexander, C. Scott; Asay, James Russell

    2011-06-01

    A new experimental technique to measure material shear strength at high pressures has been developed for use on magnetohydrodynamic (MHD) drive pulsed power platforms. The technique is referred to as Magnetically-Applied Pressure-Shear (MAPS). By applying an external static magnetic field to the sample region, the MHD drive directly induces a shear stress wave in addition to the usual longitudinal stress wave. Strength is probed by passing this shear wave through a sample material where the transmissible shear stress is limited to the sample strength. The magnitude of the transmitted shear wave is measured via a transverse velocity interferometry system (VISAR) from which the sample strength is determined. The strength of materials is defined as the ability of a material to sustain deviatoric (shear) stresses. Strength is an important aspect of the response of materials subjected to compression to high pressure. Beyond the elastic response, material strength will govern at what pressure and to what extent a material will plastically deform. The MAPS technique cleverly exploits the property that, for a von Mises yield criterion at a given longitudinal stress, the maximum amplitude shear wave that can be transmitted is limited by the strength at that stress level. Successful fielding of MAPS experiments to measure shear stresses relies upon correct numerical simulation of the experiment. Complex wave interactions among forward and reflected longitudinal and shear waves, as well as the advancing magnetic diffusion front of the MHD drive, can make the design of the experiment complicated. Careful consideration must be given to driver, sample, and anvil materials; to the thicknesses of the driver, sample and anvil layers; as well as to the timing of the interacting waves. This paper will present and analyze the 2D MHD simulations used to design the MAPS experiments. The MAPS experiments are modeled using Sandia's ALEGRA-MHD simulation code. ALEGRA-MHD is an operator

  14. Somatotopic Map and Inter- and Intra-Digit Distance in Brodmann Area 2 by Pressure Stimulation.

    PubMed

    Choi, Mi-Hyun; Kim, Sung-Phil; Kim, Hyung-Sik; Gim, Seon-Young; Kim, Woo-Ram; Mun, Kyung-Ryul; Lim, Dae-Woon; Lee, Bongsoo; Chung, Soon-Cheol

    2016-01-01

    The somatotopic representation of the tactile stimulation on the finger in the brain is an essential part of understanding the human somatosensory system as well as rehabilitation and other clinical therapies. Many studies have used vibrotactile stimulations and reported finger somatotopic representations in the Brodmann area 3 (BA 3). On the contrary, few studies investigated finger somatotopic representation using pressure stimulations. Therefore, the present study aimed to find a comprehensive somatotopic representation (somatotopic map and inter- and intra-digit distance) within BA 2 of humans that could describe tactile stimulations on different joints across the fingers by applying pressure stimulation to three joints-the first (p1), second (p2), and third (p3) joints-of four fingers (index, middle, ring, and little finger). Significant differences were observed in the inter-digit distance between the first joints (p1) of the index and little fingers, and between the third joints (p3) of the index and little fingers. In addition, a significant difference was observed in the intra-digit distance between p1 and p3 of the little finger. This study suggests that a somatotopic map and inter- and intra-digit distance could be found in BA 2 in response to pressure stimulation on finger joints. PMID:27452859

  15. Somatotopic Map and Inter- and Intra-Digit Distance in Brodmann Area 2 by Pressure Stimulation

    PubMed Central

    Choi, Mi-Hyun; Kim, Sung-Phil; Kim, Hyung-Sik; Gim, Seon-Young; Kim, Woo-Ram; Mun, Kyung-Ryul; Lim, Dae-Woon; Lee, Bongsoo; Chung, Soon-Cheol

    2016-01-01

    The somatotopic representation of the tactile stimulation on the finger in the brain is an essential part of understanding the human somatosensory system as well as rehabilitation and other clinical therapies. Many studies have used vibrotactile stimulations and reported finger somatotopic representations in the Brodmann area 3 (BA 3). On the contrary, few studies investigated finger somatotopic representation using pressure stimulations. Therefore, the present study aimed to find a comprehensive somatotopic representation (somatotopic map and inter- and intra-digit distance) within BA 2 of humans that could describe tactile stimulations on different joints across the fingers by applying pressure stimulation to three joints-the first (p1), second (p2), and third (p3) joints-of four fingers (index, middle, ring, and little finger). Significant differences were observed in the inter-digit distance between the first joints (p1) of the index and little fingers, and between the third joints (p3) of the index and little fingers. In addition, a significant difference was observed in the intra-digit distance between p1 and p3 of the little finger. This study suggests that a somatotopic map and inter- and intra-digit distance could be found in BA 2 in response to pressure stimulation on finger joints. PMID:27452859

  16. CPAP (Continuous Positive Airway Pressure)

    MedlinePlus

    ... Links Related Topics Bronchopulmonary Dysplasia Respiratory Distress Syndrome Sleep Apnea Sleep Studies Send a link to NHLBI to ... by people who have breathing problems, such as sleep apnea . CPAP also may be used to treat preterm ...

  17. Continuous Positive Airway Pressure (CPAP)

    MedlinePlus

    ... these issues. What Are the Alternative Treatments For Sleep Apnea? Lifestyle change including weight loss and exercise can help to improve sleep apnea and its related health problems. Sleep positioning and ...

  18. Airway compliance and dynamics explain the apparent discrepancy in length adaptation between intact airways and smooth muscle strips.

    PubMed

    Dowie, Jackson; Ansell, Thomas K; Noble, Peter B; Donovan, Graham M

    2016-01-01

    Length adaptation is a phenomenon observed in airway smooth muscle (ASM) wherein over time there is a shift in the length-tension curve. There is potential for length adaptation to play an important role in airway constriction and airway hyper-responsiveness in asthma. Recent results by Ansell et al., 2015 (JAP 2014 10.1152/japplphysiol.00724.2014) have cast doubt on this role by testing for length adaptation using an intact airway preparation, rather than strips of ASM. Using this technique they found no evidence for length adaptation in intact airways. Here we attempt to resolve this apparent discrepancy by constructing a minimal mathematical model of the intact airway, including ASM which follows the classic length-tension curve and undergoes length adaptation. This allows us to show that (1) no evidence of length adaptation should be expected in large, cartilaginous, intact airways; (2) even in highly compliant peripheral airways, or at more compliant regions of the pressure-volume curve of large airways, the effect of length adaptation would be modest and at best marginally detectable in intact airways; (3) the key parameters which control the appearance of length adaptation in intact airways are airway compliance and the relaxation timescale. The results of this mathematical simulation suggest that length adaptation observed at the level of the isolated ASM may not clearly manifest in the normal intact airway. PMID:26376002

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

    PubMed Central

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

    2014-01-01

    Background: Neonatal respiratory distress syndrome (RDS) in premature infants who survived and its complications are a common problem. Due to high morbidity and mechanical ventilation (MV) nowadays researchers in interested minimizing MV. To determine, in very low birth weight (BW) preterm neonates with RDS, if initial treatment with nasal intermittent mandatory ventilation (early NIMV) compared with early nasal continuous positive airway pressure (early NCPAP) obtains more favorable outcomes in terms of the duration of treatment, and the need for endotracheal tube ventilation. Methods: In this single-center randomized control trial study, infants (BW ≤ 1500 g and/or gestational age ≤ 34 weeks) with respiratory distress were considered eligible. Forty-four infants were randomly assigned to receive early-NIMV and 54 comparable infants to early-NCPAP. Surfactants were given, when FIO2 requirement was of >30%. Primary outcomes were failure of noninvasive respiratory support, that is, the need for MV in the first 48 h of life and for the duration of noninvasive respiratory support in each group. Results: 98 infants were enrolled (44 in the NIMV and 54 in the NCPAP group). The Preventive power of MV of NIMV usage (95.5%) was not lower than the NCPAP (98.1%) strength (hazard ratio: 0.21 (95% confidence interval: 0.02-2.66); P: 0.23). The duration of noninvasive respiratory support in the NIMV group was significantly shorter than NCPAP (the median (range) was 24 (18.00-48.00) h versus 48.00 (22.00-120.00) h in NIMV versus NCPAP groups; P < 0.001). Similarly, the duration of dependency on oxygen was less, for NIMV (the median (range) was 96.00 (41.00-504.00) h versus144.00 (70.00-1130.00) h in NIMV versus NCPAP groups; P: 0.009). Interestingly, time to full enteral feeds and length of hospital stay were more favorable in the NIMV versus the NCPAP group. Conclusions: Initial treatment of RDS with NIMV was safe, and well tolerated. Furthermore, NIMV had excellent

  20. Nasal continuous positive airway pressure (nCPAP) treatment for obstructive sleep apnea, road traffic accidents and driving simulator performance: a meta-analysis.

    PubMed

    Antonopoulos, Constantine N; Sergentanis, Theodoros N; Daskalopoulou, Styliani S; Petridou, Eleni Th

    2011-10-01

    We used meta-analysis to synthesize current evidence regarding the effect of nasal continuous positive airway pressure (nCPAP) on road traffic accidents in patients with obstructive sleep apnea (OSA) as well as on their performance in driving simulator. The primary outcomes were real accidents, near miss accidents, and accident-related events in the driving simulator. Pooled odds ratios (ORs), incidence rate ratios (IRRs) and standardized mean differences (SMDs) were appropriately calculated through fixed or random effects models after assessing between-study heterogeneity. Furthermore, risk differences (RDs) and numbers needed to treat (NNTs) were estimated for real and near miss accidents. Meta-regression analysis was performed to examine the effect of moderator variables and publication bias was also evaluated. Ten studies on real accidents (1221 patients), five studies on near miss accidents (769 patients) and six studies on the performance in driving simulator (110 patients) were included. A statistically significant reduction in real accidents (OR=0.21, 95% CI=0.12-0.35, random effects model; IRR=0.45, 95% CI=0.34-0.59, fixed effects model) and near miss accidents (OR=0.09, 95% CI=0.04-0.21, random effects model; IRR=0.23, 95% CI=0.08-0.67, random effects model) was observed. Likewise, a significant reduction in accident-related events was observed in the driving simulator (SMD=-1.20, 95% CI=-1.75 to -0.64, random effects). The RD for real accidents was -0.22 (95% CI=-0.32 to -0.13, random effects), with NNT equal to five patients (95% CI=3-8), whereas for near miss accidents the RD was -0.47 (95% CI=-0.69 to -0.25, random effects), with NNT equal to two patients (95% CI=1-4). For near miss accidents, meta-regression analysis suggested that nCPAP seemed more effective among patients entering the studies with higher baseline accident rates. In conclusion, all three meta-analyses demonstrated a sizeable protective effect of nCPAP on road traffic accidents, both

  1. The impact of increased mean airway pressure on contrast-enhanced MRI measurement of regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), regional mean transit time (rMTT), and regional cerebrovascular resistance (rCVR) in human volunteers.

    PubMed

    Kolbitsch, C; Lorenz, I H; Hörmann, C; Schocke, M; Kremser, C; Zschiegner, F; Felber, S; Benzer, A

    2000-11-01

    Contrast-enhanced magnetic resonance imaging (MRI) measurement of cerebral perfusion is a diagnostic procedure increasingly gaining access to clinical practice not only in spontaneously breathing patients but also in mechanically ventilated patients. Effects of increased mean airway pressure on cerebral perfusion are entirely possible. Therefore, the present study used continuous positive airway pressure (CPAP) (12 cm H2O) to study the effects of increased mean airway pressure on cerebral perfusion in volunteers. CPAP significantly reduced regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV) but increased regional mean transit time (rMTT) and regional cerebrovascular resistance (rCVR). Active vasoconstriction (e.g., arterial) and/or passive compression of capillary and/or venous vessel areas are the most likely underlying mechanisms. The number of interhemispheric differences in rCBF, rCBV, rMTT, and rCVR found at baseline rose when mean airway pressure was increased. These results, although obtained in volunteers, should be taken into consideration for the interpretation of contrast-enhanced MRI perfusion measurements in mechanically ventilated patients with an increased positive airway pressure. PMID:11098799

  2. Statistical parametric mapping of the regional distribution and ontogenetic scaling of foot pressures during walking in Asian elephants (Elephas maximus).

    PubMed

    Panagiotopoulou, Olga; Pataky, Todd C; Hill, Zoe; Hutchinson, John R

    2012-05-01

    Foot pressure distributions during locomotion have causal links with the anatomical and structural configurations of the foot tissues and the mechanics of locomotion. Elephant feet have five toes bound in a flexible pad of fibrous tissue (digital cushion). Does this specialized foot design control peak foot pressures in such giant animals? And how does body size, such as during ontogenetic growth, influence foot pressures? We addressed these questions by studying foot pressure distributions in elephant feet and their correlation with body mass and centre of pressure trajectories, using statistical parametric mapping (SPM), a neuro-imaging technology. Our results show a positive correlation between body mass and peak pressures, with the highest pressures dominated by the distal ends of the lateral toes (digits 3, 4 and 5). We also demonstrate that pressure reduction in the elephant digital cushion is a complex interaction of its viscoelastic tissue structure and its centre of pressure trajectories, because there is a tendency to avoid rear 'heel' contact as an elephant grows. Using SPM, we present a complete map of pressure distributions in elephant feet during ontogeny by performing statistical analysis at the pixel level across the entire plantar/palmar surface. We hope that our study will build confidence in the potential clinical and scaling applications of mammalian foot pressures, given our findings in support of a link between regional peak pressures and pathogenesis in elephant feet. PMID:22496296

  3. Noninvasive clearance of airway secretions.

    PubMed

    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

  4. Brachycephalic airway syndrome: pathophysiology and diagnosis.

    PubMed

    Lodato, Dena L; Hedlund, Cheryl S

    2012-07-01

    Brachycephalic airway syndrome (BAS) is a group of abnormalities that result in upper airway obstruction. Primary malformations include stenotic nares, elongated soft palate, and hypoplastic trachea, which cause an increase in negative pressure within the upper airways that can eventually lead to secondary abnormalities such as everted laryngeal saccules, everted tonsils, and laryngeal and tracheal collapse. Abnormal nasopharyngeal turbinates are also encountered, but have not been classified as primary or secondary. BAS is readily diagnosed, and quality of life is improved with appropriate medical and/or surgical management. PMID:22847322

  5. Using seismic reflection surveying to map gas-generated excess pore pressures at Finneidfjord, Norway

    NASA Astrophysics Data System (ADS)

    Baise, L. G.; Morgan, E. C.; Vanneste, M. W.; Longva, O.; Lecomte, I.; McAdoo, B. G.

    2009-12-01

    On the 20th of June, 1996, a multi-phase landslide that initiated under water and retrogressed onto land ultimately killed 4 people, destroyed several houses, and undermined a major highway in Finneidfjord, Norway, an area with a known history of landsliding in the Holocene. Geological and environmental conditions inherent to the 1996 slide include excess fluid/gas pressure (particularly in gas-bearing sediment), lateral and vertical lithological variability, slide-prone sediment layers, and changes in the water table due to heavy rainfall. In this study, we quantify pore pressures within the free gas accumulation at very shallow sub-surface depths using seismic reflection data. The trapped gas is thought to originate from the decomposition of river-deposited organic material. The gas front (a few meters below the seabed) produces a strong, polarity-reversed reflection, dramatically attenuating sub-surface reflections. On X-ray images of cores collected from the 5 km2 large gas zone, gas appears as vesicular spots. We use a previously published method incorporating continuous wavelet transforms to quantify attenuation produced by gas-bearing sediment. Taking the output from this method, and knowing or assuming values for other physical parameters, we invert for in situ pressure and equivalent thickness of the free gas layer. We compare our results to pressure data collected from a single piezometer penetrating the gas front, and then incorporate geostatistical methods to interpolate between our seismic profiles. The end product is a map of excess pore pressure estimates, which can be used in conjunction with bathymetry data and cores for more accurate slope stability analyses, ultimately identifying the more sensitive areas of the fjord.

  6. Upper airway test (image)

    MedlinePlus

    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 ...

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

    PubMed Central

    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) (p<0.0001), minimal SpO2 (p=0.002), oxygen desaturation index (p=0.001), and total sleep 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

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

    PubMed

    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

  9. Careers in Airway Science.

    ERIC Educational Resources Information Center

    Federal Aviation Administration (DOT), Washington, DC.

    The Federal Aviation Administration (FAA) has initiated the Airway Science curriculum as a method of preparing the next generation of aviation technicians and managers. This document: (1) discusses the FAA's role in the Airway Science program; (2) describes some of the career fields that FAA offers to Airway Science graduates (air traffic control…

  10. Pressure pain mapping of the wrist extensors after repeated eccentric exercise at high intensity.

    PubMed

    Delfa de la Morena, José M; Samani, Afshin; Fernández-Carnero, Josué; Hansen, Ernst A; Madeleine, Pascal

    2013-11-01

    The purpose of this study was to investigate adaptation mechanisms after 2 test rounds consisting of eccentric exercise using pressure pain imaging of the wrist extensors. Pressure pain thresholds (PPTs) were assessed over 12 points forming a 3 × 4 matrix over the dominant elbow in 12 participants. From the PPT assessments, pressure pain maps were computed. Delayed onset muscle soreness was induced in an initial test round of high-intensity eccentric exercise. The second test round performed 7 days later aimed at resulting in adaptation. The PPTs were assessed before, immediately after, and 24 hours after the 2 test rounds of eccentric exercise. For the first test round, the mean PPT was significantly lower 24 hours after exercise compared with before exercise (389.5 ± 64.1 vs. 500.5 ± 66.4 kPa, respectively; p = 0.02). For the second test round, the PPT was similar before and 24 hours after (447.7 ± 51.3 vs. 458.0 ± 73.1 kPa, respectively; p = 1.0). This study demonstrated adaptive effects of the wrist extensors monitored by pain imaging technique in healthy untrained humans. A lack of hyperalgesia, i.e., no decrease in PPT underlined adaptation after the second test round of eccentric exercise performed 7 days after the initial test round. The present findings showed for the first time that repeated eccentric exercise performed twice over 2 weeks protects the wrist extensor muscles from developing exacerbated pressure pain sensitivity. Thus, the addition of eccentric components to training regimens should be considered to induce protective adaptation. PMID:23442281

  11. Pleiotropic Effect of a High Resolution Mapped Blood Pressure QTL on Tumorigenesis

    PubMed Central

    Cheng, Xi; Waghulde, Harshal; Mell, Blair; Smedlund, Kathryn; Vazquez, Guillermo; Joe, Bina

    2016-01-01

    This study is focused on a translationally significant, genome-wide-association-study (GWAS) locus for cardiovascular disease (QT-interval) on human chromosome 17. We have previously validated and high resolution mapped the homologous genomic segment of this human locus to <42.5 kb on rat chromosome 10. This <42.5 kb segment in rats regulates both QT-interval and blood pressure and contains a single protein-coding gene, rififylin (Rffl). The expression of Rffl in the hearts and kidneys is differential between Dahl S and S.LEW congenic rats, which are the strains used for mapping this locus. Our previous study points to altered rate of endocytic recycling as the underlying mechanism, through which Rffl operates to control both QT-interval and blood pressure. Interestingly, Rffl also contributes to tumorigenesis by repressing caspases and tumor suppressor genes. Moreover, the expression of Methyl-CpG Binding Domain Protein 2 (Mbd2) in the hearts and kidneys is also higher in the S.LEW congenic strain than the background (control) Dahl S strain. Mbd2 can repress methylated tumor suppressor genes. These data suggest that the S.LEW congenic strain could be more susceptible to tumorigenesis. To test this hypothesis, the S and S.LEW strains were compared for susceptibility to azoxymethane-induced colon tumors. The number of colon tumors was significantly higher in the S.LEW congenic strain compared with the S rat. Transcriptomic analysis confirmed that the chemical carcinogenesis pathway was significantly up-regulated in the congenic strain. These studies provide evidence for a GWAS-validated genomic segment on rat chromosome 10 as being important for the regulation of cardiovascular function and tumorigenesis. PMID:27073989

  12. Influence of High Hydrostatic Pressure on Epitope Mapping of Tobacco Mosaic Virus Coat Protein

    PubMed Central

    Bonafe, Carlos Francisco Sampaio; Arns, Clarice Weis

    2014-01-01

    Abstract In this study, we investigated the effect of high hydrostatic pressure (HHP) on tobacco mosaic virus (TMV), a model virus in immunology and one of the most studied viruses to date. Exposure to HHP significantly altered the recognition epitopes when compared to sera from mice immunized with native virus. These alterations were studied further by combining HHP with urea or low temperature and then inoculating the altered virions into Balb-C mice. The antibody titers and cross-reactivity of the resulting sera were determined by ELISA. The antigenicity of the viral particles was maintained, as assessed by using polyclonal antibodies against native virus. The antigenicity of canonical epitopes was maintained, although binding intensities varied among the treatments. The patterns of recognition determined by epitope mapping were cross checked with the prediction algorithms for the TMVcp amino acid sequence to infer which alterations had occurred. These findings suggest that different cleavage sites were exposed after the treatments and this was confirmed by epitope mapping using sera from mice immunized with virus previously exposed to HHP. PMID:24605789

  13. Reverberation Mapping of the Broad-line Region in NGC 5548: Evidence for Radiation Pressure?

    NASA Astrophysics Data System (ADS)

    Lu, Kai-Xing; Du, Pu; Hu, Chen; Li, Yan-Rong; Zhang, Zhi-Xiang; Wang, Kai; Huang, Ying-Ke; Bi, Shao-Lan; Bai, Jin-Ming; Ho, Luis C.; Wang, Jian-Min

    2016-08-01

    NGC 5548 is the best-observed reverberation-mapped active galactic nucleus with long-term, intensive monitoring. Here we report results from a new observational campaign between 2015 January and July. We measure the centroid time lag of the broad Hβ emission line with respect to the 5100 Å continuum and obtain {τ }{{cent}}={7.20}-0.35+1.33 days in the rest frame. This yields a black hole mass of {M}\\bullet ={8.71}-2.61+3.21× {10}7{M}ȯ using a broad Hβ line dispersion of 3124 ± 302 km s‑1 and a virial factor of {f}{{{BLR}}}=6.3+/- 1.5 for the broad-line region (BLR), consistent with the mass measurements from previous Hβ campaigns. The high-quality data allow us to construct a velocity-binned delay map for the broad Hβ line, which shows a symmetric response pattern around the line center, a plausible kinematic signature of virialized motion of the BLR. Combining all the available measurements of Hβ time lags and the associated mean 5100 Å luminosities over 18 campaigns between 1989 and 2015, we find that the Hβ BLR size varies with the mean optical luminosity, but, interestingly, with a possible delay of {2.35}-1.25+3.47 years. This delay coincides with the typical BLR dynamical timescale of NGC 5548, indicating that the BLR undergoes dynamical changes, possibly driven by radiation pressure.

  14. Mapping of high pressure metamorphics in the As Sifah region, NE Oman using ASTER data

    NASA Astrophysics Data System (ADS)

    Rajendran, Sankaran; Nasir, Sobhi

    2015-02-01

    The high pressure metamorphic zone of As Sifah area in the Saih Hatat window, NE Oman plays a vital role to study global tectonic setting, metamorphism, transport direction and age of initial ophiolite emplacement. Scientists and researchers are keen in determining the protolith, structural evolution, and timing and metamorphic conditions of the Saih Hatat area. In this study, mapping of the metamorphic zone and discrimination of associated rock formations occurred in the As Sifah region is carried out using visible and near infrared-shortwave infrared (VNIR-SWIR) spectral bands of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and well known image processing methods such as image decorrelation, Principal Component Analysis (PCA) and Spectral Angel Mapper (SAM). The study delineated the region of metamorphic zone and discriminated the different metamorphic and carbonate rocks of the study area characterized by hydroxyl (OH) and carbonate bearing minerals. The assessment of accuracy for the occurrence and spatial distribution of major lithological units provided the overall accuracy of 96.06% with Kappa Coefficient = 0.95 in the matrix of Maximum Likelihood (ML) and compared with the Spectral Angle Mapper (SAM) and Spectral Information Divergence (SID) algorithms. The occurrence of such minerals are detected and confirmed by SAM supervised classification method. The study also describes the spectral character of metamorphic and carbonates minerals. The metamorphic zone and associated rock types interpreted over the images are verified in the field and checked for their occurrences and spatial distributions. The occurrence of CO3 bearing carbonate minerals and OH bearing metamorphic minerals are confirmed further under microscope, XRD analysis and PIMA spectral measurements in the laboratory studies. The study proved sensor capability of ASTER to discriminate metamorphic rocks from associated formations and detection of different mineral

  15. Automated airway evaluation system for multi-slice computed tomography using airway lumen diameter, airway wall thickness and broncho-arterial ratio

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Lerallut, Jean-Francois

    2006-03-01

    Pulmonary diseases such as bronchiectasis, asthma, and emphysema are characterized by abnormalities in airway dimensions. Multi-slice computed tomography (MSCT) has become one of the primary means to depict these abnormalities, as the availability of high-resolution near-isotropic data makes it possible to evaluate airways at oblique angles to the scanner plane. However, currently, clinical evaluation of airways is typically limited to subjective visual inspection only: systematic evaluation of the airways to take advantage of high-resolution data has not proved practical without automation. We present an automated method to quantitatively evaluate airway lumen diameter, wall thickness and broncho-arterial ratios. In addition, our method provides 3D visualization of these values, graphically illustrating the location and extent of disease. Our algorithm begins by automatic airway segmentation to extract paths to the distal airways, and to create a map of airway diameters. Normally, airway diameters decrease as paths progress distally; failure to taper indicates abnormal dilatation. Our approach monitors airway lumen diameters along each airway path in order to detect abnormal profiles, allowing even subtle degrees of pathologic dilatation to be identified. Our method also systematically computes the broncho-arterial ratio at every terminal branch of the tree model, as a ratio above 1 indicates potentially abnormal bronchial dilatation. Finally, the airway wall thickness is computed at corresponding locations. These measurements are used to highlight abnormal branches for closer inspection, and can be summed to compute a quantitative global score for the entire airway tree, allowing reproducible longitudinal assessment of disease severity. Preliminary tests on patients diagnosed with bronchiectasis demonstrated rapid identification of lack of tapering, which also was confirmed by corresponding demonstration of elevated broncho-arterial ratios.

  16. The Physiologically Difficult Airway.

    PubMed

    Mosier, Jarrod M; Joshi, Raj; Hypes, Cameron; Pacheco, Garrett; Valenzuela, Terence; Sakles, John C

    2015-12-01

    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. PMID:26759664

  17. The Physiologically Difficult Airway

    PubMed Central

    Mosier, Jarrod M.; Joshi, Raj; Hypes, Cameron; Pacheco, Garrett; Valenzuela, Terence; Sakles, John C.

    2015-01-01

    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. PMID:26759664

  18. Epithelium damage and protection during reopening of occluded airways in a physiologic microfluidic pulmonary airway model.

    PubMed

    Tavana, Hossein; Zamankhan, Parsa; Christensen, Paul J; Grotberg, James B; Takayama, Shuichi

    2011-08-01

    Airways of the peripheral lung are prone to closure at low lung volumes. Deficiency or dysfunction of pulmonary surfactant during various lung diseases compounds this event by destabilizing the liquid lining of small airways and giving rise to occluding liquid plugs in airways. Propagation of liquid plugs in airways during inflation of the lung exerts large mechanical forces on airway cells. We describe a microfluidic model of small airways of the lung that mimics airway architecture, recreates physiologic levels of pulmonary pressures, and allows studying cellular response to repeated liquid plug propagation events. Substantial cellular injury happens due to the propagation of liquid plugs devoid of surfactant. We show that addition of a physiologic concentration of a clinical surfactant, Survanta, to propagating liquid plugs protects the epithelium and significantly reduces cell death. Although the protective role of surfactants has been demonstrated in models of a propagating air finger in liquid-filled airways, this is the first time to study the protective role of surfactants in liquid plugs where fluid mechanical stresses are expected to be higher than in air fingers. Our parallel computational simulations revealed a significant decrease in mechanical forces in the presence of surfactant, confirming the experimental observations. The results support the practice of providing exogenous surfactant to patients in certain clinical settings as a protective mechanism against pathologic flows. More importantly, this platform provides a useful model to investigate various surface tension-mediated lung diseases at the cellular level. PMID:21487664

  19. Understanding creep in sandstone reservoirs - theoretical deformation mechanism maps for pressure solution in granular materials

    NASA Astrophysics Data System (ADS)

    Hangx, Suzanne; Spiers, Christopher

    2014-05-01

    -boundary diffusion and precipitation on pore walls. As a first step to better describe creep in sands and sandstones, we have derived a simple model for intergranular pressure solution (IPS) within an ordered pack of spherical grains, employing existing IPS rate models, such as those derived by Renard et al. (1999) and Spiers et al. (2004). This universal model is able to predict the conditions under which each of the respective pressure solution serial processes, i.e. diffusion, precipitation or dissolution, is dominant. In essence, this creates generic deformation mechanism maps for any granular material. We have used our model to predict the amount and rate of compaction for sandstone reservoirs, and compared our predictions to known subsidence rates for reservoirs around the world. This gives a first order-comparison to verify whether or not IPS is an important mechanism in controlling reservoir compaction.

  20. Mapping.

    ERIC Educational Resources Information Center

    Kinney, Douglas M.; McIntosh, Willard L.

    1979-01-01

    The area of geological mapping in the United States in 1978 increased greatly over that reported in 1977; state geological maps were added for California, Idaho, Nevada, and Alaska last year. (Author/BB)

  1. S. aureus haemolysin A-induced IL-8 and IL-6 release from human airway epithelial cells is mediated by activation of p38- and Erk-MAP kinases and additional, cell type-specific signalling mechanisms.

    PubMed

    Räth, Susann; Ziesemer, Sabine; Witte, Amelie; Konkel, Anne; Müller, Christian; Hildebrandt, Petra; Völker, Uwe; Hildebrandt, Jan-Peter

    2013-07-01

    Soluble virulence-associated factors of Staphylococcus aureus like haemolysin A (Hla) induce secretion of chemo/cytokines from airway epithelial cells. To elucidate the potential roles of specific signalling pathways in this response, we treated 16HBE14o-, S9 or A549 cells with recombinant Hla (rHla). In a dose-dependent manner, rHla induced secretion of IL-8 in all three cell types, but IL-6 release only in 16HBE14o- and S9 cells. rHla-mediated secretion of IL-8 and IL-6 was suppressed by pre-incubation of cells with inhibitors of Erk type or p38 MAP kinases, indicating that activation of these signalling pathways is essential for IL-8 release in all three cell types and for IL-6 release in 16HBE14o- and S9 cells. The rHla-mediated phosphorylation and activation of p38 MAP kinase seem to depend on elevations in [Ca(2+)]i, an early response in rHla-treated cells. Inhibitors of calmodulin or calcium/calmodulin-dependent kinase II attenuated rHla-mediated release of IL-8 in 16HBE14o- and A549 cells and of IL-6 in 16HBE14o- cells. This indicates that rHla may mediate simultaneous activation of calmodulin-dependent processes as additional prerequisites for chemo/cytokine secretion.However, the inhibitors of calmodulin-dependent signalling did not affect rHla-induced p38 MAP kinase phosphorylation, indicating that this pathway works in parallel with p38 MAP kinase. PMID:23347173

  2. 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

    PubMed Central

    Goel, Amrit K; Talwar, Deepak; Jain, Sushil K

    2015-01-01

    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. PMID:25983407

  3. Engineering Airway Epithelium

    PubMed Central

    Soleas, John P.; 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 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. PMID:22523471

  4. Estimation of two-dimensional intraventricular velocity and pressure maps by digital processing conventional color-Doppler sequences

    NASA Astrophysics Data System (ADS)

    Garcia, Damien; Del Alamo, Juan C.; Tanne, David; Cortina, Cristina; Yotti, Raquel; Fernandez-Aviles, Francisco; Bermejo, Javier

    2008-11-01

    Clinical echocardiographic quantification of blood flow in the left ventricle is limited because Doppler methods only provide one velocity component. We developed a new technique to obtain two-dimensional flow maps from conventional transthoracic echocardiographic acquisitions. Velocity and pressure maps were calculated from color-Doppler velocity (apical long-axis view) by solving the continuity and Euler equations under the assumptions of zero transverse fluxes of mass and momentum. This technique is fast, clinically-compliant and does not require any specific training. Particle image velocimetry experiments performed in an atrioventricular duplicator showed that the circulation and size of the diastolic vortex was quantified accurately. Micromanometer measurements in pigs showed that apex-base pressure differences extracted from two-dimensional maps qualitatively agreed with micromanometer data. Initial clinical measurements in healthy volunteers showed a large prograde vortex. Additional retrograde vortices appeared in patients with dilated cardiomyopathy and left ventricular hypertrophy.

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

    NASA Astrophysics Data System (ADS)

    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 < Ca < 0.05. This effect diminished by decrease in airways diameter. This approach will help elucidate surfactant distribution in airways and develop effective SRT strategies.

  6. CD38 and Airway hyperresponsiveness: Studies on human airway smooth muscle cells and mouse models

    PubMed Central

    Guedes, Alonso GP; Deshpande, Deepak A; Dileepan, Mythili; Walseth, Timothy F; Panettieri, Reynold A; Subramanian, Subbaya; Kannan, Mathur S

    2015-01-01

    Asthma is an inflammatory disease in which altered calcium regulation, contractility and airway smooth muscle (ASM) proliferation contribute to airway hyperresponsiveness and airway wall remodeling. The enzymatic activity of CD38, a cell-surface protein expressed in human ASM cells, generates calcium mobilizing second messenger molecules such as cyclic ADP-ribose. CD38 expression in human ASM cells is augmented by cytokines (e.g. TNF-α) that requires activation of MAP kinases and the transcription factors, NF-ƙB and AP-1 and post-transcriptionally regulated by miR-140-3p and miR-708 by binding to 3’ Untranslated Region of CD38 as well as by modulating the activation of signaling mechanisms involved in its regulation. Mice deficient in CD38 exhibit reduced airway responsiveness to inhaled methacholine relative to response in wild-type mice. Intranasal challenge of CD38 deficient mice with TNF-α or IL-13, or the environmental fungus Alternaria alternata, causes significantly attenuated methacholine responsiveness compared to wild-type mice, with comparable airway inflammation. Reciprocal bone marrow transfer studies revealed partial restoration of airway hyperresponsiveness to inhaled methacholine in the Cd38 deficient mice. These studies provide evidence for CD38 involvement in the development of airway hyperresponsiveness, a hallmark feature of asthma. Future studies aimed at drug discovery and delivery targeting CD38 expression and/or activity are warranted. PMID:25594684

  7. Non-invasive pulmonary blood flow analysis and blood pressure mapping derived from 4D flow MRI

    NASA Astrophysics Data System (ADS)

    Delles, Michael; Rengier, Fabian; Azad, Yoo-Jin; Bodenstedt, Sebastian; von Tengg-Kobligk, Hendrik; Ley, Sebastian; Unterhinninghofen, Roland; Kauczor, Hans-Ulrich; Dillmann, Rüdiger

    2015-03-01

    In diagnostics and therapy control of cardiovascular diseases, detailed knowledge about the patient-specific behavior of blood flow and pressure can be essential. The only method capable of measuring complete time-resolved three-dimensional vector fields of the blood flow velocities is velocity-encoded magnetic resonance imaging (MRI), often denoted as 4D flow MRI. Furthermore, relative pressure maps can be computed from this data source, as presented by different groups in recent years. Hence, analysis of blood flow and pressure using 4D flow MRI can be a valuable technique in management of cardiovascular diseases. In order to perform these tasks, all necessary steps in the corresponding process chain can be carried out in our in-house developed software framework MEDIFRAME. In this article, we apply MEDIFRAME for a study of hemodynamics in the pulmonary arteries of five healthy volunteers. The study included measuring vector fields of blood flow velocities by phase-contrast MRI and subsequently computing relative blood pressure maps. We visualized blood flow by streamline depictions and computed characteristic values for the left and the right pulmonary artery (LPA and RPA). In all volunteers, we observed a lower amount of blood flow in the LPA compared to the RPA. Furthermore, we visualized blood pressure maps using volume rendering and generated graphs of pressure differences between the LPA, the RPA and the main pulmonary artery. In most volunteers, blood pressure was increased near to the bifurcation and in the proximal LPA, leading to higher average pressure values in the LPA compared to the RPA.

  8. Conquering the difficult airway.

    PubMed

    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

  9. Mechanical Properties of the Upper Airway

    PubMed Central

    Strohl, Kingman P.; Butler, James P.; Malhotra, Atul

    2013-01-01

    The importance of the upper airway (nose, pharynx, and larynx) in health and in the pathogenesis of sleep apnea, asthma, and other airway diseases, discussed elsewhere in the Comprehensive Physiology series, prompts this review of the biomechanical properties and functional aspects of the upper airway. There is a literature based on anatomic or structural descriptions in static circumstances, albeit studied in limited numbers of individuals in both health and disease. As for dynamic features, the literature is limited to studies of pressure and flow through all or parts of the upper airway and to the effects of muscle activation on such features; however, the links between structure and function through airway size, shape, and compliance remain a topic that is completely open for investigation, particularly through analyses using concepts of fluid and structural mechanics. Throughout are included both historically seminal references, as well as those serving as signposts or updated reviews. This article should be considered a resource for concepts needed for the application of biomechanical models of upper airway physiology, applicable to understanding the pathophysiology of disease and anticipated results of treatment interventions. PMID:23723026

  10. Biodiversity Pressure Maps to evaluate the impact of land use and land cover change on Endangered Ecological Communities

    NASA Astrophysics Data System (ADS)

    Chisholm, L. A.; Gill, N.

    2014-12-01

    The dynamics of biodiversity are associated with human activities such as land use and land cover change (LULCC). An integrated spatial approach to identify the effects of LULCC is helpful to determine the impact or pressure of human activities on biodiversity. The concept of creating 'biodiversity pressure maps' includes the use of spatial technologies (remote sensing, GIS) over time on areas of sensitivity, for example, areas classified as endangered ecological communities (EEC). The use of a cross-tabulation matrix often forms the basis of creating pressure maps, yet spatial datasets appropriate as input are not always available. The focus of this study was to investigate and evaluate spatial datasets and cross-tabulation techniques useful for producing biodiversity pressure maps. A method will be presented in the form of a case study for an area in the Shoalhaven Local Government Area on the south coast of NSW, Australia. This area is a focus of investigation of the spatial distribution of invasive plants and landholder management practices.

  11. Brachycephalic airway syndrome: management.

    PubMed

    Lodato, Dena L; Hedlund, Cheryl S

    2012-08-01

    Brachycephalic airway syndrome (BAS) is a group of primary and secondary abnormalities that result in upper airway obstruction. Several of these abnormalities can be addressed medically and/or surgically to improve quality of life. This article reviews potential complications, anesthetic considerations, recovery strategies, and outcomes associated with medical and surgical management of BAS. PMID:22935992

  12. Simvastatin Inhibits Airway Hyperreactivity

    PubMed Central

    Zeki, Amir A.; Franzi, Lisa; Last, Jerold; Kenyon, Nicholas J.

    2009-01-01

    Rationale: Statin use has been linked to improved lung health in asthma and chronic obstructive pulmonary disease. We hypothesize that statins inhibit allergic airway inflammation and reduce airway hyperreactivity via a mevalonate-dependent mechanism. Objectives: To determine whether simvastatin attenuates airway inflammation and improves lung physiology by mevalonate pathway inhibition. Methods: BALB/c mice were sensitized to ovalbumin over 4 weeks and exposed to 1% ovalbumin aerosol over 2 weeks. Simvastatin (40 mg/kg) or simvastatin plus mevalonate (20 mg/kg) was injected intraperitoneally before each ovalbumin exposure. Measurements and Main Results: Simvastatin reduced total lung lavage leukocytes, eosinophils, and macrophages (P < 0.05) in the ovalbumin-exposed mice. Cotreatment with mevalonate, in addition to simvastatin, reversed the antiinflammatory effects seen with simvastatin alone (P < 0.05). Lung lavage IL-4, IL-13, and tumor necrosis factor-α levels were all reduced by treatment with simvastatin (P < 0.05). Simvastatin treatment before methacholine bronchial challenge increased lung compliance and reduced airway hyperreactivity (P = 0.0001). Conclusions: Simvastatin attenuates allergic airway inflammation, inhibits key helper T cell type 1 and 2 chemokines, and improves lung physiology in a mouse model of asthma. The mevalonate pathway appears to modulate allergic airway inflammation, while the beneficial effects of simvastatin on lung compliance and airway hyperreactivity may be independent of the mevalonate pathway. Simvastatin and similar agents that modulate the mevalonate pathway may prove to be treatments for inflammatory airway diseases, such as asthma. PMID:19608720

  13. Controversies in Pediatric Perioperative Airways

    PubMed Central

    Klučka, Jozef; Štourač, Petr; Štoudek, Roman; Ťoukálková, Michaela; Harazim, Hana; Kosinová, Martina

    2015-01-01

    Pediatric airway management is a challenge in routine anesthesia practice. Any airway-related complication due to improper procedure can have catastrophic consequences in pediatric patients. The authors reviewed the current relevant literature using the following data bases: Google Scholar, PubMed, Medline (OVID SP), and Dynamed, and the following keywords: Airway/s, Children, Pediatric, Difficult Airways, and Controversies. From a summary of the data, we identified several controversies: difficult airway prediction, difficult airway management, cuffed versus uncuffed endotracheal tubes for securing pediatric airways, rapid sequence induction (RSI), laryngeal mask versus endotracheal tube, and extubation timing. The data show that pediatric anesthesia practice in perioperative airway management is currently lacking the strong evidence-based medicine (EBM) data that is available for adult subpopulations. A number of procedural steps in airway management are derived only from adult populations. However, the objective is the same irrespective of patient age: proper securing of the airway and oxygenation of the patient. PMID:26759809

  14. Nonlinear Compliance Modulates Dynamic Bronchoconstriction in a Multiscale Airway Model

    PubMed Central

    Hiorns, Jonathan E.; Jensen, Oliver E.; Brook, Bindi S.

    2014-01-01

    The role of breathing and deep inspirations (DI) in modulating airway hyperresponsiveness remains poorly understood. In particular, DIs are potent bronchodilators of constricted airways in nonasthmatic subjects but not in asthmatic subjects. Additionally, length fluctuations (mimicking DIs) have been shown to reduce mean contractile force when applied to airway smooth muscle (ASM) cells and tissue strips. However, these observations are not recapitulated on application of transmural pressure (PTM) oscillations (that mimic tidal breathing and DIs) in isolated intact airways. To shed light on this paradox, we have developed a biomechanical model of the intact airway, accounting for strain-stiffening due to collagen recruitment (a large component of the extracellular matrix (ECM)), and dynamic actomyosin-driven force generation by ASM cells. In agreement with intact airway studies, our model shows that PTM fluctuations at particular mean transmural pressures can lead to only limited bronchodilation. However, our model predicts that moving the airway to a more compliant point on the static pressure-radius relationship (which may involve reducing mean PTM), before applying pressure fluctuations, can generate greater bronchodilation. This difference arises from competition between passive strain-stiffening of ECM and force generation by ASM yielding a highly nonlinear relationship between effective airway stiffness and PTM, which is modified by the presence of contractile agonist. Effectively, the airway at its most compliant may allow for greater strain to be transmitted to subcellular contractile machinery. The model predictions lead us to hypothesize that the maximum possible bronchodilation of an airway depends on its static compliance at the PTM about which the fluctuations are applied. We suggest the design of additional experimental protocols to test this hypothesis. PMID:25517167

  15. Nasal Airway Resistance: Its Measurement and Regulation.

    ERIC Educational Resources Information Center

    Hamilton, Lyle H.

    1979-01-01

    Reviews studies of regulation of nasal airway resistance (Rn). Describes methods of calculating Rn by measuring pressure-flow relationship. Data are presented on improved methods for measuring Rn and effects for expiratory and inspiratory Rn after topical application of phenylephrine nasal decongestant spray. (Author/SA)

  16. Geometrical Model of Solar Radiation Pressure Based on High-Performing Galileo Clocks - First Geometrical Mapping of the Yarkowsky effect

    NASA Astrophysics Data System (ADS)

    Svehla, Drazen; Rothacher, Markus; Hugentobler, Urs; Steigenberger, Peter; Ziebart, Marek

    2014-05-01

    Solar radiation pressure is the main source of errors in the precise orbit determination of GNSS satellites. All deficiencies in the modeling of Solar radiation pressure map into estimated terrestrial reference frame parameters as well as into derived gravity field coefficients and altimetry results when LEO orbits are determined using GPS. Here we introduce a new approach to geometrically map radial orbit perturbations of GNSS satellites using highly-performing clocks on board the first Galileo satellites. Only a linear model (time bias and time drift) needs to be removed from the estimated clock parameters and the remaining clock residuals map all radial orbit perturbations along the orbit. With the independent SLR measurements, we show that a Galileo clock is stable enough to map radial orbit perturbations continuously along the orbit with a negative sign in comparison to SLR residuals. Agreement between the SLR residuals and the clock residuals is at the 1 cm RMS for an orbit arc of 24 h. Looking at the clock parameters determined along one orbit revolution over a period of one year, we show that the so-called SLR bias in Galileo and GPS orbits can be explained by the translation of the determined orbit in the orbital plane towards the Sun. This orbit translation is due to thermal re-radiation and not accounting for the Sun elevation in the parameterization of the estimated Solar radiation pressure parameters. SLR ranging to GNSS satellites takes place typically at night, e.g. between 6 pm and 6 am local time when the Sun is in opposition to the satellite. Therefore, SLR observes only one part of the GNSS orbit with a negative radial orbit error that is mapped as an artificial bias in SLR observables. The Galileo clocks clearly show orbit translation for all Sun elevations: the radial orbit error is positive when the Sun is in conjuction (orbit noon) and negative when the Sun is in opposition (orbit midnight). The magnitude of this artificial negative SLR bias

  17. Airway dysfunction in swimmers.

    PubMed

    Bougault, Valérie; Boulet, Louis-Philippe

    2012-05-01

    Elite competitive swimmers are particularly affected by airway disorders that are probably related to regular and intense training sessions in a chlorinated environment. Upper and lower airway respiratory symptoms, rhinitis, airway hyper-responsiveness, and exercise-induced bronchoconstriction are highly prevalent in these athletes, but their influence on athletic performance is still unclear. The authors reviewed the main upper and lower respiratory ailments observed in competitive swimmers who train in indoor swimming pools, their pathophysiology, clinical significance and possible effects on performance. Issues regarding the screening of these disorders, their management and preventive measures are addressed. PMID:22247299

  18. Meteorological conditions along airways

    NASA Technical Reports Server (NTRS)

    Gregg, W R

    1927-01-01

    This report is an attempt to show the kind of meteorological information that is needed, and is in part available, for the purpose of determining operating conditions along airways. In general, the same factors affect these operating conditions along all airways though in varying degree, depending upon their topographic, geographic, and other characteristics; but in order to bring out as clearly as possible the nature of the data available, a specific example is taken, that of the Chicago-Dallas airway on which regular flying begins this year (1926).

  19. A Pilot Study on the Efficacy of Continuous Positive Airway Pressure on the Manifestations of Ménière's Disease in Patients with Concomitant Obstructive Sleep Apnea Syndrome

    PubMed Central

    Nakayama, Meiho; Masuda, Ayako; Ando, Kayoko Bhardwaj; Arima, Sachie; Kabaya, Kayoko; Inagaki, Akira; Nakamura, Yoshihisa; Suzuki, Motohiko; Brodie, Hilary; Diaz, Rodney C.; Murakami, Shingo

    2015-01-01

    Objective: To evaluate the effect of continuous positive airway pressure (CPAP) therapy on Ménière's disease patients with concomitant obstructive sleep apnea syndrome (OSAS), since recent reports suggest OSAS may cause dysfunction of the vestibular system. Study Design: Prospective study using CPAP administered to patients diagnosed with “Definite Ménière's disease” according to the guidelines of the American Academy of Otolaryngology— Head and Neck Surgery and combined with OSAS. Setting: University hospital. Methods: Twenty consecutive patients, 14 male and 6 female with active, unilateral, cochleovestibular Ménière's disease refractory to medical management who also had concurrent OSAS as defined by International Classification of Sleep Disorders, Second Edition were selected to undergo solitary CPAP therapy. Audiometric testing, caloric testing, and DHI survey were conducted before and after CPAP therapy and compared to assess effectiveness of CPAP therapy as utilized for treatment of Ménière's disease. Results: Although caloric testing did not show significant difference, audiometric testing and results of dizziness handicap inventory were significantly improved (p < 0.05) after CPAP therapy only, without standard treatment for Ménière's disease. Conclusions: Recent reports have suggested that OSAS may cause dysfunction of the vestibular system. We investigated whether standard therapy for OSAS would be of benefit in the management of vertigo and hearing loss in Ménière's disease patients. Our study cohort demonstrated significant improvement in both DHI and audiometric testing following solitary CPAP therapy for OSAS. Solitary CPAP therapy may become a new effective treatment strategy for Ménière's disease patients with OSAS, not just only for control of dizziness and vertigo but also for potential benefit of hearing. Citation: Nakayama M, Masuda A, Ando KB, Arima S, Kabaya K, Inagaki A, Nakamura Y, Suzuki M, Brodie H, Diaz RC, Murakami S

  20. Patterns of recruitment and injury in a heterogeneous airway network model.

    PubMed

    Stewart, Peter S; Jensen, Oliver E

    2015-10-01

    In respiratory distress, lung airways become flooded with liquid and may collapse due to surface-tension forces acting on air-liquid interfaces, inhibiting gas exchange. This paper proposes a mathematical multiscale model for the mechanical ventilation of a network of occluded airways, where air is forced into the network at a fixed tidal volume, allowing investigation of optimal recruitment strategies. The temporal response is derived from mechanistic models of individual airway reopening, incorporating feedback on the airway pressure due to recruitment. The model accounts for stochastic variability in airway diameter and stiffness across and between generations. For weak heterogeneity, the network is completely ventilated via one or more avalanches of recruitment (with airways recruited in quick succession), each characterized by a transient decrease in the airway pressure; avalanches become more erratic for airways that are initially more flooded. However, the time taken for complete ventilation of the network increases significantly as the network becomes more heterogeneous, leading to increased stresses on airway walls. The model predicts that the most peripheral airways are most at risk of ventilation-induced damage. A positive-end-expiratory pressure reduces the total recruitment time but at the cost of larger stresses exerted on airway walls. PMID:26423440

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

    PubMed

    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

  2. Upper Airway Collapsibility and Genioglossus Activity in Adolescents during Sleep

    PubMed Central

    Huang, Jingtao; Pinto, Swaroop J.; Yuan, Haibo; Katz, Eliot S.; Karamessinis, Laurie R.; Bradford, Ruth M.; Gallagher, Paul R.; Hannigan, James T.; Nixon, Thomas; Ward, Michelle B.; Lee, Yin N.; Marcus, Carole L.

    2012-01-01

    Study Objectives: Obese patients develop obstructive sleep apnea syndrome (OSAS), at least in part because of a narrowed upper airway. However, many obese adolescents do not develop OSAS, despite having a presumably narrower airway. The reasons for this phenomenon are unclear. The authors hypothesized that obese controls have a compensatory neuromuscular response to subatmospheric pressure loads during sleep, making them less likely to develop upper airway collapse. Design: Patients underwent pressure-flow measurements during sleep while wearing intraoral electrodes to measure genioglossal electromyography (EMGgg). Two techniques were applied to decrease nasal pressure (PN) to subatmospheric levels, resulting in an activated and relatively hypotonic upper airway. Setting: Sleep laboratory. Participants: There were 35 obese patients with OSAS, 28 obese controls, and 43 lean controls. Results: In the activated state, the two control groups had a flatter slope of the pressure-flow relationship and a more negative critical closing pressure (less collapsible) than the OSAS group. In the hypotonic state, the lean controls had a flatter slope of the pressure-flow relationship than the OSAS and obese control groups. In the activated state, the slope of EMGgg versus PN was greater in the obese control group than in the OSAS or lean control groups (P = 0.002 and P = 0.028, respectively); there were no differences in the hypotonic state. Conclusions: Obese controls have vigorous upper airway neuromuscular responses during sleep. Upper airway reflexes normally decline during adolescent development. It is speculated that obese adolescents without OSAS maintain protective upper airway reflexes during adolescent development, whereas those who go on to develop OSAS do not. Citation: Huang J; Pinto SJ; Yuan H; Katz ES; Karamessinis LR; Bradford RM; Gallagher PR; Hannigan JT; Nixon T; Ward MB; Lee YN; Marcus CL. Upper airway collapsibility and genioglossus activity in adolescents

  3. Airway management in trauma.

    PubMed

    Langeron, O; Birenbaum, A; Amour, J

    2009-05-01

    Maintenance of a patent and prevention of aspiration are essential for the management of the trauma patient, that requires experienced physicians in airway control techniques. Difficulties of the airway control in the trauma setting are increased by the vital failures, the risk of aspiration, the potential cervical spine injury, the combative patient, and the obvious risk of difficult tracheal intubation related to specific injury related to the trauma. Endotracheal intubation remains the gold standard in trauma patient airway management and should be performed via the oral route with a rapid sequence induction and a manual in-line stabilization maneuver, to decrease the risks previously mentioned. Different techniques to control the airway in trauma patients are presented: improvement of the laryngoscopic vision, lighted stylet tracheal intubation, retrograde technique for orotracheal intubation, the laryngeal mask and the intubating laryngeal mask airways, the combitube and cricothyroidotomy. Management of the airway in trauma patients requires regular training in these techniques and the knowledge of complementary techniques allowing tracheal intubation or oxygenation to overcome difficult intubation and to prevent major complications as hypoxemia and aspiration. PMID:19412149

  4. A pilot study investigating the effects of continuous positive airway pressure treatment and weight-loss surgery on autonomic activity in obese obstructive sleep apnea patients☆, ☆☆

    PubMed Central

    Bakker, Jessie P.; Campana, Lisa M.; Montesi, Sydney B.; Balachandran, Jayshankar; DeYoung, Pamela N.; Smales, Erik; Patel, Sanjay R.; Malhotra, Atul

    2015-01-01

    Background We have previously demonstrated that severity of obstructive sleep apnea (OSA) as measured by the apnea–hypopnea index (AHI) is a significant independent predictor of readily-computed time-domain metrics of short-term heart rate variability (HRV). Methods We aimed to assess time-domain HRV measured over 5-min while awake in a trial of obese subjects undergoing one of two OSA therapies: weight-loss surgery (n = 12, 2 males, median and interquartile range (IQR) for BMI 43.7 [42.0, 51.4] kg/m2, and AHI 18.1 [16.3, 67.5] events/h) or continuous positive airway pressure (CPAP) (n = 15, 11 males, median BMI 33.8 [31.3, 37.9] kg/m2, and AHI 36.5 [24.7, 77.3] events/h). Polysomnography was followed by electrocardiography during wakefulness; measurements were repeated at 6 and 12–18 months post-intervention. Results Despite similar measurements at baseline, subjects who underwent surgery exhibited greater improvement in short-term HRV than those who underwent CPAP (p = 0.04). Conclusions Our data suggest a possible divergence in autonomic function between the effects of weight loss resulting from bariatric surgery, and the amelioration of obstructive respiratory events resulting from CPAP treatment. Randomized studies are necessary before clinical recommendations can be made. PMID:24636793

  5. Clinical effectiveness and cost-effectiveness results from the randomised controlled Trial of Oral Mandibular Advancement Devices for Obstructive sleep apnoea-hypopnoea (TOMADO) and long-term economic analysis of oral devices and continuous positive airway pressure.

    PubMed Central

    Sharples, Linda; Glover, Matthew; Clutterbuck-James, Abigail; Bennett, Maxine; Jordan, Jake; Chadwick, Rebecca; Pittman, Marcus; East, Clare; Cameron, Malcolm; Davies, Mike; Oscroft, Nick; Smith, Ian; Morrell, Mary; Fox-Rushby, Julia; Quinnell, Timothy

    2014-01-01

    BACKGROUND Obstructive sleep apnoea-hypopnoea (OSAH) causes excessive daytime sleepiness (EDS), impairs quality of life (QoL) and increases cardiovascular disease and road traffic accident risks. Continuous positive airway pressure (CPAP) treatment is clinically effective but undermined by intolerance, and its cost-effectiveness is borderline in milder cases. Mandibular advancement devices (MADs) are another option, but evidence is lacking regarding their clinical effectiveness and cost-effectiveness in milder disease. OBJECTIVES (1) Conduct a randomised controlled trial (RCT) examining the clinical effectiveness and cost-effectiveness of MADs against no treatment in mild to moderate OSAH. (2) Update systematic reviews and an existing health economic decision model with data from the Trial of Oral Mandibular Advancement Devices for Obstructive sleep apnoea-hypopnoea (TOMADO) and newly published results to better inform long-term clinical effectiveness and cost-effectiveness of MADs and CPAP in mild to moderate OSAH. TOMADO A crossover RCT comparing clinical effectiveness and cost-effectiveness of three MADs: self-moulded [SleepPro 1™ (SP1); Meditas Ltd, Winchester, UK]; semibespoke [SleepPro 2™ (SP2); Meditas Ltd, Winchester, UK]; and fully bespoke [bespoke MAD (bMAD); NHS Oral-Maxillofacial Laboratory, Addenbrooke's Hospital, Cambridge, UK] against no treatment, in 90 adults with mild to moderate OSAH. All devices improved primary outcome [apnoea-hypopnoea index (AHI)] compared with no treatment: relative risk 0.74 [95% confidence interval (CI) 0.62 to 0.89] for SP1; relative risk 0.67 (95% CI 0.59 to 0.76) for SP2; and relative risk 0.64 (95% CI 0.55 to 0.76) for bMAD (p < 0.001). Differences between MADs were not significant. Sleepiness [as measured by the Epworth Sleepiness Scale (ESS)] was scored 1.51 [95% CI 0.73 to 2.29 (SP1)] to 2.37 [95% CI 1.53 to 3.22 (bMAD)] lower than no treatment (p < 0.001), with SP2 and bMAD significantly better than SP1

  6. Fault diagnosis for manifold absolute pressure sensor(MAP) of diesel engine based on Elman neural network observer

    NASA Astrophysics Data System (ADS)

    Wang, Yingmin; Zhang, Fujun; Cui, Tao; Zhou, Jinlong

    2016-03-01

    Intake system of diesel engine is a strong nonlinear system, and it is difficult to establish accurate model of intake system; and bias fault and precision degradation fault of MAP of diesel engine can't be diagnosed easily using model-based methods. Thus, a fault diagnosis method based on Elman neural network observer is proposed. By comparing simulation results of intake pressure based on BP network and Elman neural network, lower sampling error magnitude is gained using Elman neural network, and the error is less volatile. Forecast accuracy is between 0.015-0.017 5 and sample error is controlled within 0-0.07. Considering the output stability and complexity of solving comprehensively, Elman neural network with a single hidden layer and with 44 nodes is presented as intake system observer. By comparing the relations of confidence intervals of the residual value between the measured and predicted values, error variance and failures in various fault types. Then four typical MAP faults of diesel engine can be diagnosed: complete failure fault, bias fault, precision degradation fault and drift fault. The simulation results show: intake pressure is observable and selection of diagnostic strategy parameter reasonably can increase the accuracy of diagnosis; the proposed fault diagnosis method only depends on data and structural parameters of observer, not depends on the nonlinear model of air intake system. A fault diagnosis method is proposed not depending system model to observe intake pressure, and bias fault and precision degradation fault of MAP of diesel engine can be diagnosed based on residuals.

  7. Role of upper airway ultrasound in airway management.

    PubMed

    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

  8. Excessive Dynamic Airway Collapse Detected Using Nondynamic CT.

    PubMed

    Harada, Yukinori; Kondo, Tomoo

    2016-01-01

    Excessive dynamic airway collapse (EDAC) has been diagnosed using dynamic CT during inspiration and expiration. We herein report an asthma patient with EDAC that was detected incidentally using nondynamic CT. The patient presented with wheezing, cough and mild fever. Treatment for the asthma did not improve her wheeze. CT revealed tracheal narrowing and bulging of the posterior bronchial wall. The patient was diagnosed with EDAC by bronchoscopy. Her wheeze improved with continuous positive airway pressure therapy. Clinicians should be aware of the airway shape when performing nondynamic CT in refractory asthma patients because recognizing the existence of EDAC may help when deciding on the treatment strategy. PMID:27250056

  9. Airway nitric oxide in microgravity

    NASA Astrophysics Data System (ADS)

    Linnarsson, D.; Gustafsson, L.; Hemmingsson, Tryggve; Frostell, C.; Paiva, M.

    2005-10-01

    Nitric Oxide (NO), a molecule with a wide range of biological effects, is found in exhaled gas. Elevation of expired NO is an early sign of airway inflammation in asthma and dust inhalation. Animal experiments have demonstrated a marked increase of expired NO after venous gas emboli (bubbles, VGE), which may occur after decompression in conjunction with extravehicular activity (EVA). For this MAP project, astronauts will perform a simple inhalation-exhalation procedure weekly during their flights, and before and after EVA. Furthermore, the microgravity environment offers a possibility to gain new insights into how and where NO is formed in the lungs and what local effects NO may have there. The planned experiments have been made possible by recent developments of new techniques by the team's industrial partners; Aerocrine has developed a highly compact and accurate NO analyser, and Linde Gas Theapeutics has developed a highly compact device for NO administration in the inhaled air.

  10. Homozygosity by descent mapping of blood pressure in the Old Order Amish: evidence for sex specific genetic architecture

    PubMed Central

    McArdle, Patrick F; Dytch, Harvey; O'Connell, Jeffery R; Shuldiner, Alan R; Mitchell, Braxton D; Abney, Mark

    2007-01-01

    Background High blood pressure is a well established risk factor for morbidity and mortality acting through heart disease, stroke and cardiovascular disease. Genome wide scans have linked regions of nearly every human chromosome to blood pressure related traits. We have capitalized on beneficial qualities of the Old Order Amish of Lancaster, PA, a closed founder population with a relatively small number of founders, to perform a genome wide homozygosity by descent mapping scan. Each individual in the study has a non zero probability of consanguinity. Systolic and diastolic blood pressures are shown to have appreciable dominance variance components. Results Areas of two chromosomes were identified as suggestive of linkage to SBP and 5 areas to DBP in either the overall or sex specific analyses. The strongest evidence for linkage in the overall sample was to Chromosome 18q12 (LOD = 2.6 DBP). Sex specific analyses identified a linkage on Chromosome 4p12-14 (LOD in men only = 3.4 SBP). At Chromosome 2q32-33, an area where we previously reported significant evidence for linkage to DBP using a conventional identity by descent approach, the LOD was 1.4; however an appreciable sex effect was observed with men accounting for most of the linkage (LOD in men only = 2.6). Conclusion These results add evidence to a sex specific genetic architecture to blood pressure related traits, particularly in regions of linkage on chromosome 2, 4 and 18. PMID:17908314

  11. Mean lung pressure during adult high-frequency oscillatory ventilation: an experimental study using a lung model.

    PubMed

    Hirayama, Takahiro; Nagano, Osamu; Shiba, Naoki; Yumoto, Tetsuya; Sato, Keiji; Terado, Michihisa; Ugawa, Toyomu; Ichiba, Shingo; Ujike, Yoshihito

    2014-12-01

    In adult high-frequency oscillatory ventilation (HFOV), stroke volume (SV) and mean lung pressure (PLung) are important for lung protection. We measured the airway pressure at the Y-piece and the lung pressure during HFOV using a lung model and HFOV ventilators for adults (R100 and 3100B). The lung model was made of a 20-liter, airtight rigid plastic container (adiabatic compliance: 19.3 ml/cmH2O) with or without a resistor (20 cmH2O/l/sec). The ventilator settings were as follows: mean airway pressure (MAP), 30 cmH2O; frequency, 5-15 Hz (every 1 Hz); airway pressure amplitude (AMP), maximum;and % of inspiratory time (IT), 50% for R100, 33% or 50% for 3100B. The measurements were also performed with an AMP of 2/3 or 1/3 maximum at 5, 10 and 15 Hz. The PLung and the measured MAP were not consistently identical to the setting MAP in either ventilator, and decreasing IT decreased the PLung in 3100B. In conclusion, we must pay attention to the possible discrepancy between the PLung and the setting MAP during adult HFOV. PMID:25519026

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

    PubMed

    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

  13. 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.

    PubMed

    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

  14. The influence of controlled mandatory ventilation (CMV), intermittent mandatory ventilation (IMV) and biphasic intermittent positive airway pressure (BIPAP) on duration of intubation and consumption of analgesics and sedatives. A prospective analysis in 596 patients following adult cardiac surgery.

    PubMed

    Rathgeber, J; Schorn, B; Falk, V; Kazmaier, S; Spiegel, T; Burchardi, H

    1997-11-01

    The aim of the study was the determination of the influence of ventilation modes on the consumption of analgesics and sedatives, duration of intubation and pulmonary gas exchange. Assist/controlled mandatory ventilation (S-CMV, 123 patients), synchronized intermittent mandatory ventilation (S-IMV, 431 patients) and biphasic positive airway pressure ventilation (BIPAP, 42 patients) were compared in a prospective, controlled, open clinical trial over an 18-month period. Five hundred and ninety-six adult patients with normal pulmonary function before surgery and uneventful course following coronary artery bypass graft surgery were studied. Patients ventilated with BIPAP had a significantly shorter mean duration of intubation (10.1 h, P < 0.05) than patients treated with S-IMV (14.7 h) and S-CMV (13.2 h). In the S-CMV group, 39.9% of the patients required single or multiple doses of midazolam, but only 13.5% in the S-IMV group and 9.5% in the BIPAP group. The mean total amount of midazolam administered to these patients was significantly higher in the S-CMV group (8.8 mg) than in the S-IMV group (6.6 mg, P < 0.05) and in the BIPAP group (4.3 mg, P < 0.05). The consumption of pethidine and piritramide did not differ between S-CMV and S-IMV, but was significantly lower during BIPAP (P < 0.05). After extubation the patients' PaCO2 was highest in the S-CMV group. We conclude that ventilatory support with BIPAP reduces the consumption of analgesics and sedatives, and the duration of intubation. The possibility of unrestricted spontaneous breathing in all phases of the respiratory cycle is considered to be the reason. BIPAP seems to be an alternative to S-CMV and S-IMV in short-term ventilated patient. PMID:9466092

  15. A multicentre, randomised controlled, non-inferiority trial, comparing high flow therapy with nasal continuous positive airway pressure as primary support for preterm infants with respiratory distress (the HIPSTER trial): study protocol

    PubMed Central

    Roberts, Calum T; Owen, Louise S; Manley, Brett J; Donath, Susan M; Davis, Peter G

    2015-01-01

    Introduction High flow (HF) therapy is an increasingly popular mode of non-invasive respiratory support for preterm infants. While there is now evidence to support the use of HF to reduce extubation failure, there have been no appropriately designed and powered studies to assess the use of HF as primary respiratory support soon after birth. Our hypothesis is that HF is non-inferior to the standard treatment—nasal continuous positive airway pressure (NCPAP)— as primary respiratory support for preterm infants. Methods and analysis The HIPSTER trial is an unblinded, international, multicentre, randomised, non-inferiority trial. Eligible infants are preterm infants of 28–36+6 weeks’ gestational age (GA) who require primary non-invasive respiratory support for respiratory distress in the first 24 h of life. Infants are randomised to treatment with either HF or NCPAP. The primary outcome is treatment failure within 72 h after randomisation, as determined by objective oxygenation, blood gas, and apnoea criteria, or the need for urgent intubation and mechanical ventilation. Secondary outcomes include the incidence of intubation, pneumothorax, bronchopulmonary dysplasia, nasal trauma, costs associated with hospital care and parental stress. With a specified non-inferiority margin of 10%, using a two-sided 95% CI and 90% power, the study requires 375 infants per group (total 750 infants). Ethics and dissemination Ethical approval has been granted by the relevant human research ethics committees at The Royal Women's Hospital (13/12), The Royal Children's Hospital (33144A), The Mercy Hospital for Women (R13/34), and the South-Eastern Norway Regional Health Authority (2013/1657). The trial is currently recruiting at 9 centres in Australia and Norway. The trial results will be published in peer-reviewed international journals, and presented at national and international conferences. Trial registration number Australian New Zealand Clinical Trials Registry ID: ACTRN

  16. A constant altitude flight survey method for mapping atmospheric ambient pressures and systematic radar errors

    NASA Technical Reports Server (NTRS)

    Larson, T. J.; Ehernberger, L. J.

    1985-01-01

    The flight test technique described uses controlled survey runs to determine horizontal atmospheric pressure variations and systematic altitude errors that result from space positioning measurements. The survey data can be used not only for improved air data calibrations, but also for studies of atmospheric structure and space positioning accuracy performance. The examples presented cover a wide range of radar tracking conditions for both subsonic and supersonic flight to an altitude of 42,000 ft.

  17. Continuous wireless pressure monitoring and mapping with ultra-small passive sensors for health monitoring and critical care

    NASA Astrophysics Data System (ADS)

    Chen, Lisa Y.; Tee, Benjamin C.-K.; Chortos, Alex L.; Schwartz, Gregor; Tse, Victor; J. Lipomi, Darren; Wong, H.-S. Philip; McConnell, Michael V.; Bao, Zhenan

    2014-10-01

    Continuous monitoring of internal physiological parameters is essential for critical care patients, but currently can only be practically achieved via tethered solutions. Here we report a wireless, real-time pressure monitoring system with passive, flexible, millimetre-scale sensors, scaled down to unprecedented dimensions of 1 × 1 × 0.1 cubic millimeters. This level of dimensional scaling is enabled by novel sensor design and detection schemes, which overcome the operating frequency limits of traditional strategies and exhibit insensitivity to lossy tissue environments. We demonstrate the use of this system to capture human pulse waveforms wirelessly in real time as well as to monitor in vivo intracranial pressure continuously in proof-of-concept mice studies using sensors down to 2.5 × 2.5 × 0.1 cubic millimeters. We further introduce printable wireless sensor arrays and show their use in real-time spatial pressure mapping. Looking forward, this technology has broader applications in continuous wireless monitoring of multiple physiological parameters for biomedical research and patient care.

  18. Continuous wireless pressure monitoring and mapping with ultra-small passive sensors for health monitoring and critical care.

    PubMed

    Chen, Lisa Y; Tee, Benjamin C-K; Chortos, Alex L; Schwartz, Gregor; Tse, Victor; Lipomi, Darren J; Wong, H-S Philip; McConnell, Michael V; Bao, Zhenan

    2014-01-01

    Continuous monitoring of internal physiological parameters is essential for critical care patients, but currently can only be practically achieved via tethered solutions. Here we report a wireless, real-time pressure monitoring system with passive, flexible, millimetre-scale sensors, scaled down to unprecedented dimensions of 1 × 1 × 0.1 cubic millimeters. This level of dimensional scaling is enabled by novel sensor design and detection schemes, which overcome the operating frequency limits of traditional strategies and exhibit insensitivity to lossy tissue environments. We demonstrate the use of this system to capture human pulse waveforms wirelessly in real time as well as to monitor in vivo intracranial pressure continuously in proof-of-concept mice studies using sensors down to 2.5 × 2.5 × 0.1 cubic millimeters. We further introduce printable wireless sensor arrays and show their use in real-time spatial pressure mapping. Looking forward, this technology has broader applications in continuous wireless monitoring of multiple physiological parameters for biomedical research and patient care. PMID:25284074

  19. Modeling the Nonlinear Motion of the Rat Central Airways.

    PubMed

    Ibrahim, G; Rona, A; Hainsworth, S V

    2016-01-01

    Advances in volumetric medical imaging techniques allowed the subject-specific modeling of the bronchial flow through the first few generations of the central airways using computational fluid dynamics (CFD). However, a reliable CFD prediction of the bronchial flow requires modeling of the inhomogeneous deformation of the central airways during breathing. This paper addresses this issue by introducing two models of the central airways motion. The first model utilizes a node-to-node mapping between the discretized geometries of the central airways generated from a number of successive computed tomography (CT) images acquired dynamically (without breath hold) over the breathing cycle of two Sprague-Dawley rats. The second model uses a node-to-node mapping between only two discretized airway geometries generated from the CT images acquired at end-exhale and at end-inhale along with the ventilator measurement of the lung volume change. The advantage of this second model is that it uses just one pair of CT images, which more readily complies with the radiation dosage restrictions for humans. Three-dimensional computer aided design geometries of the central airways generated from the dynamic-CT images were used as benchmarks to validate the output from the two models at sampled time-points over the breathing cycle. The central airway geometries deformed by the first model showed good agreement to the benchmark geometries within a tolerance of 4%. The central airway geometry deformed by the second model better approximated the benchmark geometries than previous approaches that used a linear or harmonic motion model. PMID:26592166

  20. Brief mechanical ventilation impacts airway cartilage properties in neonatal lambs

    PubMed Central

    Kim, Minwook; Pugarelli, Joan; Miller, Thomas L.; Wolfson, Marla R.; Dodge, George R.; Shaffer, Thomas H.

    2012-01-01

    Ultrasound imaging allows in vivo assessment of tracheal kinetics and cartilage structure. To date, the impact of mechanical ventilation (MV) on extracellular matrix (ECM) in airway cartilage is unclear, but an indication of its functional and structural change may support the development of protective therapies. The objective of this study was to characterize changes in mechanical properties of the neonatal airway during MV with alterations in cartilage ECM. Trachea segments were isolated in a neonatal lamb model; ultrasound dimensions and pressure-volume relationships were measured on sham (no MV; n = 6) and MV (n = 7) airways for 4 h. Tracheal cross-sections were harvested at 4 h, tissues were fixed and stained, and Fourier transform infrared imaging spectroscopy (FT-IRIS) was performed. Over 4 h of MV, bulk modulus (28%) and elastic modulus (282%) increased. The MV tracheae showed higher collagen, proteoglycan content, and collagen integrity (new tissue formation); whereas no changes were seen in the controls. These data are clinically relevant in that airway properties can be correlated with MV and changes in cartilage extracellular matrix. Mechanical ventilation increases the in vivo dimensions of the trachea, and is associated with evidence of airway tissue remodeling. Injury to the neonatal airway from MV may have relevance for the development of tracheomalacia. We demonstrated active airway tissue remodeling during MV using a FT-IRIS technique which identifies changes in ECM. PMID:22170596

  1. Epithelial hyperplasia, airways

    Cancer.gov

    Number of respiratory epithelial cells is increased diffusely or focally. Frequently luminal protrusions are observed, sometimes forming papillae. Mucous (goblet) cell metaplastic hyperplasia is a variant, in which the respiratory epithelium of conducting airways is replaced by mucous cells either as a single or a pseudostratified layer.

  2. Advances in prehospital airway management

    PubMed Central

    Jacobs, PE; Grabinsky, A

    2014-01-01

    Prehospital airway management is a key component of emergency responders and remains an important task of Emergency Medical Service (EMS) systems worldwide. The most advanced airway management techniques involving placement of oropharyngeal airways such as the Laryngeal Mask Airway or endotracheal tube. Endotracheal tube placement success is a common measure of out-of-hospital airway management quality. Regional variation in regard to training, education, and procedural exposure may be the major contributor to the findings in success and patient outcome. In studies demonstrating poor outcomes related to prehospital-attempted endotracheal intubation (ETI), both training and skill level of the provider are usually often low. Research supports a relationship between the number of intubation experiences and ETI success. National standards for certification of emergency medicine provider are in general too low to guarantee good success rate in emergency airway management by paramedics and physicians. Some paramedic training programs require more intense airway training above the national standard and some EMS systems in Europe staff their system with anesthesia providers instead. ETI remains the cornerstone of definitive prehospital airway management, However, ETI is not without risk and outcomes data remains controversial. Many systems may benefit from more input and guidance by the anesthesia department, which have higher volumes of airway management procedures and extensive training and experience not just with training of airway management but also with different airway management techniques and adjuncts. PMID:24741499

  3. Supraglottic airway devices in children

    PubMed Central

    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

  4. Management of the Traumatized Airway.

    PubMed

    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

  5. Effects of pentobarbital on upper airway patency during sleep.

    PubMed

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

    2010-09-01

    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 (P(crit)). 12 healthy subjects received pentobarbital (100 mg) or placebo in a double-blind, crossover protocol. During wakefulness, we measured the genioglossus reflex response to negative pressure pulses. During sleep, carbon dioxide was insufflated into the inspired air. Airway pressure was then decreased in a stepwise fashion until arousal from sleep. With basal breathing during sleep: flow rate was lower in volunteers given pentobarbital; end-tidal CO(2) concentration and upper airway resistance were greater; and P(crit) was unaffected (pentobarbital mean ± SD -11.7 ± 4.5 versus placebo -10.25 ± 3.6 cmH(2)O; p = 0.11). Pentobarbital increased the time to arousal (297 ± 63s versus 232 ± 67 s; p<0.05), at which time phasic genioglossus EMG was higher (6.2 ± 4.8% maximal versus 3.1 ± 3%; p<0.05) as were CO(2) levels. The increase in genioglossus EMG after CO(2) administration was greater after pentobarbital versus placebo. Pentobarbital did not affect the genioglossus negative-pressure reflex. Pentobarbital increases the time to arousal and stimulates genioglossus muscle activity, but it also increases upper airway resistance during sleep. PMID:20032012

  6. Effects of pentobarbital on upper airway patency during sleep

    PubMed Central

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

    2012-01-01

    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). 12 healthy subjects received pentobarbital (100 mg) or placebo in a double-blind, crossover protocol. During wakefulness, we measured the genioglossus reflex response to negative pressure pulses. During sleep, carbon dioxide was insufflated into the inspired air. Airway pressure was then decreased in a stepwise fashion until arousal from sleep. With basal breathing during sleep: flow rate was lower in volunteers given pentobarbital; end-tidal CO2 concentration and upper airway resistance were greater; and Pcrit was unaffected (pentobarbital mean±sd -11.7±4.5 versus placebo -10.25±3.6 cmH2O; p=0.11). Pentobarbital increased the time to arousal (297±63s versus 232±67 s; p<0.05), at which time phasic genioglossus EMG was higher (6.2±4.8% maximal versus 3.1±3%; p<0.05) as were CO2 levels. The increase in genioglossus EMG after CO2 administration was greater after pentobarbital versus placebo. Pentobarbital did not affect the genioglossus negative-pressure reflex. Pentobarbital increases the time to arousal and stimulates genioglossus muscle activity, but it also increases upper airway resistance during sleep. PMID:20032012

  7. The Tulip GT® airway versus the facemask and Guedel airway: a randomised, controlled, cross-over study by Basic Life Support-trained airway providers in anaesthetised patients.

    PubMed

    Shaikh, A; Robinson, P N; Hasan, M

    2016-03-01

    We performed a randomised, controlled, cross-over study of lung ventilation by Basic Life Support-trained providers using either the Tulip GT® airway or a facemask with a Guedel airway in 60 anaesthetised patients. Successful ventilation was achieved if the provider produced an end-tidal CO2 > 3.5 kPa and a tidal volume > 250 ml in two of the first three breaths, within 60 sec and within two attempts. Fifty-seven (95%) providers achieved successful ventilation using the Tulip GT compared with 35 (58%) using the facemask (p < 0.0001). Comparing the Tulip GT and facemask, the mean (SD) end-tidal CO2 was 5.0 (0.7) kPa vs 2.5 (1.5) kPa, tidal volume was 494 (175) ml vs 286 (186) ml and peak inspiratory pressure was 18.3 (3.4) cmH2 O vs 13.6 (7) cmH2 O respectively (all p < 0.0001). Forty-seven (78%) users favoured the Tulip GT airway. These results are similar to a previous manikin study using the same protocol, suggesting a close correlation between human and manikin studies for this airway device. We conclude that the Tulip GT should be considered as an adjunct to airway management both within and outside hospitals when ventilation is being undertaken by Basic Life Support-trained airway providers. PMID:26684684

  8. A Novel MRI-compatible Tactile Stimulator for Cortical Mapping of Foot Sole Pressure Stimuli with fMRI

    PubMed Central

    Hao, Ying; Manor, Brad; Liu, Jing; Zhang, Kai; Chai, Yufeng; Lipsitz, Lewis; Peng, Chung-Kang; Novak, Vera; Wang, Xiaoying; Zhang, Jue; Fang, Jing

    2013-01-01

    Foot sole somatosensory feedback is critical to motor control and declines with aging and disease. To enable study of cortical networks underlying foot sole somatosensation we developed a pneumatic tactile stimulator capable of producing 1-DOF oscillations with preset waveform, frequency (≤10 Hz), force magnitude (5-500 N), duty cycle (20%-100%) and contacted surface area over which pressures are applied to the foot sole. Image tests (anatomical/functional/field map) of a phantom demonstrated that the device is compatible with 3T MRI. GRE-EPI images of seven healthy young adults using a typical block-designed 1Hz sinusoidal stimulation protocol revealed significant activation contralaterally within the primary somatosensory cortex and paracentral gyrus, and bilaterally within the secondary somatosensory cortex. The stimulation system may therefore serve as a research tool to study functional brain networks involved in the perception and modulation of foot sole somatosensation and its relationship to motor control. PMID:22678849

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

    PubMed Central

    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

  10. A reevaluation of the interrupter technique for airway resistance measurement

    NASA Technical Reports Server (NTRS)

    Jackson, A. C.; Milhorn, H. T., Jr.; Norman, J. R.

    1974-01-01

    An attempt was made to obtain a better insight into the actual transient response of airway opening pressure (Pao) following rapid occlusion. With this knowledge it was hoped to be able to clarify the reason for the overestimations found by other investigators, and possibly to obtain a more accurate method of estimating alveolar pressure just prior to interruption. This would result in an improved method for estimating airway resistance. Use of an extrapolation method was found to provide an improved correlation between resistances determined by the interruptor technique and those found by the plethysmograph in normal subjects.

  11. Upper Airway Mechanics

    PubMed Central

    Verbraecken, Johan A.; De Backer, Wilfried A.

    2009-01-01

    This review discusses the pathophysiological aspects of sleep-disordered breathing, with focus on upper airway mechanics in obstructive and central sleep apnoea, Cheyne-Stokes respiration and obesity hypoventilation syndrome. These disorders constitute the end points of a spectrum with distinct yet interrelated mechanisms that lead to substantial pathology, i.e. increased upper airway collapsibility, control of breathing instability, increased work of breathing, disturbed ventilatory system mechanics and neurohormonal changes. Concepts are changing. Although sleep apnoea is considered more and more to be an increased loop gain disorder, the central type of apnoea is now considered as an obstructive event, because it causes pharyngeal narrowing, associated with prolonged expiration. Although a unifying concept for the pathogenesis is lacking, it seems that these patients are in a vicious circle. Knowledge of common patterns of sleep-disordered breathing may help to identify these patients and guide therapy. PMID:19478479

  12. Comparison of i-gel supraglottic airway and LMA-ProSeal™ in pediatric patients under controlled ventilation

    PubMed Central

    Saran, Sai; Mishra, Sandeep Kumar; Badhe, Ashok Shankar; Vasudevan, Arumugam; Elakkumanan, Lenin Babu; Mishra, Gayatri

    2014-01-01

    Background: i-gel™ and the ProSeal™ laryngeal mask airway (PLMA) are two supraglottic airway devices with gastric channel used for airway maintenance in anesthesia. This study was designed to evaluate the efficacy of i-gel compared with PLMA for airway maintenance in pediatric patients under general anesthesia with controlled ventilation. Materials and Methods: A total of 60 American Society of Anesthesiologists physical status 1 and 2 patients were included in the study and randomized to either i-gel or PLMA group. After induction of anesthesia using a standardized protocol for all the patients, one of supraglottic airway devices was inserted. Insertion parameters, ease of gastric tube insertion and fiber-optic scoring of the glottis were noted. Airway parameters such as end-tidal carbon dioxide (EtCO2), peak airway pressures and leak airway pressures were noted. Patients were observed for any complications in the first 12 h of the post-operative period. Results: Both groups were comparable in terms of ease of insertion, number of attempts and other insertion parameters. Ease of gastric tube insertion, EtCO2, airway pressures (peak and leak airway pressure) and fiber-optic view of the glottis were comparable in both groups. There were no clinically significant complications in the first 12 h of the post-operative period. Conclusion: i-gel is as effective as PLMA in pediatric patients under controlled ventilation. PMID:24803756

  13. Brachycephalic airway syndrome.

    PubMed

    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

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

    PubMed

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

    2016-09-01

    The safety of high pressure source ventilation (jet ventilation) is dependent upon upper airway patency to facilitate adequate passive expiration and prevent increasing intrathoracic pressure and its associated deleterious sequelae. Distortions in airway anatomy may make passive expiration inadequate or impossible in some patients. We report the elective use of the Ventrain device to provide ventilation in a clinical setting of upper airway obstruction in a patient with post radiation fibrosis that had previously prevented passive expiration during attempted high pressure source ventilation. PMID:27555171

  15. Airway closure in microgravity.

    PubMed

    Dutrieue, Brigitte; Verbanck, Sylvia; Darquenne, Chantal; Prisk, G Kim

    2005-08-25

    Recent single breath washout (SBW) studies in microgravity and on the ground have suggested an important effect of airway closure on gas mixing in the human lung, reflected particularly in the phase III slope of vital capacity SBW and bolus tests. In order to explore this effect, we designed a SBW in which subjects inspired 2-l from residual volume (RV) starting with a 150 ml bolus of He and SF6. In an attempt to vary the pattern of airways closure configuration before the test, the experiments were conducted in 1G and in microgravity during parabolic flight allowing the pre-test expiration to RV to be either in microgravity or at 1.8 G, with the actual test gas inhalation performed entirely in microgravity. Contrary to our expectations, the measured phase III slope and phase IV height and volume obtained from seven subjects in microgravity were essentially identical irrespective of the gravity level during the pre-test expiration to RV. The results suggest that airway closure configuration at RV before the test inspiration has no apparent impact on phases III and IV generation. PMID:15979418

  16. Epithelial cell deformation during surfactant-mediated airway reopening: a theoretical model.

    PubMed

    Naire, Shailesh; Jensen, Oliver E

    2005-08-01

    A theoretical model is presented describing the reopening by an advancing air bubble of an initially liquid-filled collapsed airway lined with deformable epithelial cells. The model integrates descriptions of flow-structure interaction (accounting for nonlinear deformation of the airway wall and viscous resistance of the airway liquid flow), surfactant transport around the bubble tip (incorporating physicochemical parameters appropriate for Infasurf), and cell deformation (due to stretching of the airway wall and airway liquid flows). It is shown how the pressure required to drive a bubble into a flooded airway, peeling apart the wet airway walls, can be reduced substantially by surfactant, although the effectiveness of Infasurf is limited by slow adsorption at high concentrations. The model demonstrates how the addition of surfactant can lead to the spontaneous reopening of a collapsed airway, depending on the degree of initial airway collapse. The effective elastic modulus of the epithelial layer is shown to be a key determinant of the relative magnitude of strains generated by flow-induced shear stresses and by airway wall stretch. The model also shows how epithelial-layer compressibility can mediate strains arising from flow-induced normal stresses and stress gradients. PMID:15802368

  17. [Comparison of respiratory control responses in bronchial and external airway stenosis].

    PubMed

    Marek, W; Rasche, K; Mailänder, A; Hoffarth, H P; Ulmer, W T

    1989-11-01

    Respiratory responses during allergen-induced airway obstruction and external airway stenosis were investigated in anaesthetised sheep. The results were compared to those obtained from healthy subjects during external airway stenosis. Allergen-induced increase in airway resistance results in an increased respiratory frequency, mainly due to a shortening of expiration (TE) and only partially due to a shortening of inspiration (TI). Tidal volume is diminished while respiratory changes in oesophageal pressure (delta Poes) are increased. Both results in an increase of dynamic elastance (Edyn) representing airway resistance. Based on the increase in the slope and amplitude of inspiratory pressure (delta Poes/TI), the mean inspiratory airflow (VT/TI) remains almost unchanged. In spite of an increased ventilation PaO2 decreases, whereas PaCO2 increases only slightly. External airway stenosis, however, results in a decrease of respiratory frequency, mainly depending on a prolongation of inspiration. Changes in Poes and VT are similar to those of allergen-induced airway obstruction. delta Poes/TI, however, increases less than during allergen application and results in a decrease of mean inspiratory airflow, tidal volume and ventilation. Respiratory responses of healthy subjects during external airway stenosis were similar to those described in experimental animals. The results of our investigation show a different pattern in the control of breathing during bronchial and external stenosis-induced airway obstruction and thus indicate different vagal reflex mechanisms. PMID:2608647

  18. Catheter-Based Sensing In The Airways

    NASA Astrophysics Data System (ADS)

    Fouke, J. M.; Saunders, K. G.

    1988-04-01

    Studies attempting to define the role of the respiratory tract in heating and humidifying inspired air point to the need for sensing many variables including airway wall and airstream temperatures, humidity, and surface fluid pH and osmolarity. In order to make such measurements in vivo in human volunteers, catheter based technologies must be exploited both to assure subject safety and subject comfort. Miniturization of the electrodes or sensors becomes a top priority. This paper describes the use of thin-film microelectronic technology to fabricate a miniature, flexible sensor which can be placed directly onto the surface of the airway to measure the electrical conductance of the fluids present. From this information the osmolarity of the surface fluid was calculated. Physiologic evaluation of the device and corroboration of the calculations was performed in mongrel dogs. We also describe the successful application of current thermistor technology for the thermal mapping of the airways in humans in order to characterize the dynamic intrathoracic events that occur during breathing. The thermal probe consisted of a flexible polyvinyl tube that contained fourteen small thermistors fixed into the catheter. Data have been obtained in dozens of people, both normal subjects and asthmatic patients, under a variety of interventions. These data have substantively advanced the study of asthma, a particularly troublesome chronic obstructive pulmonary disorder.

  19. Airway distension promotes leukocyte recruitment in rat tracheal circulation.

    PubMed

    Lim, Lina H K; Wagner, Elizabeth M

    2003-11-01

    Mechanical distortion of blood vessels is known to activate endothelial cells. Whether airway distension likewise activates the vascular endothelium within the airway wall is unknown. Using intravital microscopy in the rat trachea, we investigated if airway distention with the application of positive end-expiratory pressure (PEEP) caused leukocyte recruitment to the airway. Tracheal postcapillary venules were visualized and leukocyte kinetics monitored in anesthetized, mechanically ventilated rats (80 breaths/minute, 6 ml/kg VT, 1 cm H(2)O PEEP). Leukocyte rolling velocity (Vwbc) and the number of adherent cells were not altered with normal ventilation over the course of 2 hours. Ventilation with sustained PEEP (8 cm H(2)O for 1 hour reduced Vwbc and increased adhesion, reaching a maximum at 1 hour of PEEP. Intermittent (2x and 5x) 8 cm H(2)O PEEP also induced a similar reduction in Vwbc, accompanied by an increase in adhesion. However, leukocyte recruitment after airway distension is localized to the airways because increased PEEP did not induce leukocyte recruitment in the mesenteric microcirculation or when PEEP was applied to the lung distal to the site of measurement. Pretreatment with endothelin receptor and selectin inhibitors blocked the effects of distension on leukocyte recruitment, suggesting their involvement in the proinflammatory response. PMID:12869357

  20. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway. (a... provide a patent airway. (b) Classification. Class I (general controls). The device is exempt from...

  1. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway. (a... provide a patent airway. (b) Classification. Class I (general controls). The device is exempt from...

  2. Noninvasive ventilation and the upper airway: should we pay more attention?

    PubMed

    Oppersma, Eline; Doorduin, Jonne; van der Heijden, Erik H F M; van der Hoeven, Johannes G; Heunks, Leo M A

    2013-01-01

    In an effort to reduce the complications related to invasive ventilation, the use of noninvasive ventilation (NIV) has increased over the last years in patients with acute respiratory failure. However, failure rates for NIV remain high in specific patient categories. Several studies have identified factors that contribute to NIV failure, including low experience of the medical team and patient-ventilator asynchrony. An important difference between invasive ventilation and NIV is the role of the upper airway. During invasive ventilation the endotracheal tube bypasses the upper airway, but during NIV upper airway patency may play a role in the successful application of NIV. In response to positive pressure, upper airway patency may decrease and therefore impair minute ventilation. This paper aims to discuss the effect of positive pressure ventilation on upper airway patency and its possible clinical implications, and to stimulate research in this field. PMID:24314000

  3. Noninvasive ventilation and the upper airway: should we pay more attention?

    PubMed Central

    2013-01-01

    In an effort to reduce the complications related to invasive ventilation, the use of noninvasive ventilation (NIV) has increased over the last years in patients with acute respiratory failure. However, failure rates for NIV remain high in specific patient categories. Several studies have identified factors that contribute to NIV failure, including low experience of the medical team and patient–ventilator asynchrony. An important difference between invasive ventilation and NIV is the role of the upper airway. During invasive ventilation the endotracheal tube bypasses the upper airway, but during NIV upper airway patency may play a role in the successful application of NIV. In response to positive pressure, upper airway patency may decrease and therefore impair minute ventilation. This paper aims to discuss the effect of positive pressure ventilation on upper airway patency and its possible clinical implications, and to stimulate research in this field. PMID:24314000

  4. Pathway Reconstruction of Airway Remodeling in Chronic Lung Diseases: A Systems Biology Approach

    PubMed Central

    Najafi, Ali; Masoudi-Nejad, Ali; Ghanei, Mostafa; Nourani, Mohamad-Reza; Moeini, Ali

    2014-01-01

    Airway remodeling is a pathophysiologic process at the clinical, cellular, and molecular level relating to chronic obstructive airway diseases such as chronic obstructive pulmonary disease (COPD), asthma and mustard lung. These diseases are associated with the dysregulation of multiple molecular pathways in the airway cells. Little progress has so far been made in discovering the molecular causes of complex disease in a holistic systems manner. Therefore, pathway and network reconstruction is an essential part of a systems biology approach to solve this challenging problem. In this paper, multiple data sources were used to construct the molecular process of airway remodeling pathway in mustard lung as a model of airway disease. We first compiled a master list of genes that change with airway remodeling in the mustard lung disease and then reconstructed the pathway by generating and merging the protein-protein interaction and the gene regulatory networks. Experimental observations and literature mining were used to identify and validate the master list. The outcome of this paper can provide valuable information about closely related chronic obstructive airway diseases which are of great importance for biologists and their future research. Reconstructing the airway remodeling interactome provides a starting point and reference for the future experimental study of mustard lung, and further analysis and development of these maps will be critical to understanding airway diseases in patients. PMID:24978043

  5. Blood flow and oxygen consumption with near-infrared spectroscopy and venous occlusion: spatial maps and the effect of time and pressure of inflation

    NASA Astrophysics Data System (ADS)

    Casavola, Claudia; Paunescu, Lelia A.; Fantini, Sergio; Gratton, Enrico

    2000-07-01

    We have measured the local blood flow (BF) and oxygen consumption (OC) in the human calf muscle using near- infrared spectroscopy during venous occlusion. Venous occlusion was achieved by inflating a pneumatic cuff around the thigh of the subject. We have investigated the influence of the inflation time and cuff pressure on the recovered values of BF and OC. We have found that if the cuff pressure is increased from a threshold pressure (approximately 30 mm Hg) to a critical pressure (approximately 45 mm Hg) in less than about 6 s, one measures the same values of BF and OC independent of the total inflation time and final cuff pressure. We also report nine-pixel spatial maps of BF and OC to show that this technique can lead to spatially resolved measurements of blood flow and oxygen consumption in tissues.

  6. Role of laryngeal mask airway in laparoscopic cholecystectomy.

    PubMed

    Beleña, José M; Ochoa, Ernesto Josué; Núñez, Mónica; Gilsanz, Carlos; Vidal, Alfonso

    2015-11-27

    Laparoscopic cholecystectomy is one of the most commonly performed surgical procedures and the laryngeal mask airway (LMA) is the most common supraglottic airway device used by the anesthesiologists to manage airway during general anesthesia. Use of LMA has some advantages when compared to endotracheal intubation, such as quick and ease of placement, a lesser requirement for neuromuscular blockade and a lower incidence of postoperative morbididy. However, the use of the LMA in laparoscopy is controversial, based on a concern about increased risk of regurgitation and pulmonary aspiration. The ability of these devices to provide optimal ventilation during laparoscopic procedures has been also questioned. The most important parameter to secure an adequate ventilation and oxygenation for the LMA under pneumoperitoneum condition is its seal pressure of airway. A good sealing pressure, not only state correct patient ventilation, but it reduces the potential risk of aspiration due to the better seal of airway. In addition, the LMAs incorporating a gastric access, permitting a safe anesthesia based on these commented points. We did a literature search to clarify if the use of LMA in preference to intubation provides inadequate ventilation or increase the risk of aspiration in patients undergoing laparoscopic cholecystectomy. We found evidence stating that LMA with drain channel achieves adequate ventilation for these procedures. Limited evidence was found to consider these devices completely safe against aspiration. However, we observed that the incidence of regurgitation and aspiration associated with the use of the LMA in laparoscopic surgery is very low. PMID:26649155

  7. Particle Deposition During Airway Closure

    NASA Astrophysics Data System (ADS)

    Tai, Cheng-Feng; Halpern, David; Grotberg, James B.

    2011-11-01

    Inhaled aerosol particles deposit in the lung and may be from environmental, toxic, or medical therapy sources. While much research focuses on inspiratory deposition, primarily at airway bifurcations due to inertial impaction, there are other mechanisms that allow the particles to reach the airway surface, such as gravitational settling and diffusion depending on particle size. We introduce a new mechanism not previously studied, i.e. aerosol deposition from airway closure. The airways are lined with a liquid layer. Due to the surface tension driven instability, a liquid plug can form from this layer which blocks the airway. This process of airway closure tends to occur toward the end of expiration. In this study, the efficiency of the impaction of the particles during airway closure will be investigated. The particles will be released from the upstream of the airway and convected by the air flow and deposited onto the closing liquid layer. We solve the governing equations using a finite volume approach in conjunction with a sharp interface method for the interfaces. Once the velocity field of the gas flow is obtained, the path of the particles will be calculated and the efficiency of the deposition can be estimated. We acknowledge support from the National Institutes of Health grant number NIH HL85156.

  8. Operative endoscopy of the airway

    PubMed Central

    Walters, Dustin M.

    2016-01-01

    Airway endoscopy has long been an important and useful tool in the management of thoracic diseases. As thoracic specialists have gained experience with both flexible and rigid bronchoscopic techniques, the technology has continued to evolve so that bronchoscopy is currently the foundation for diagnosis and treatment of many thoracic ailments. Airway endoscopy plays a significant role in the biopsy of tumors within the airways, mediastinum, and lung parenchyma. Endoscopic methods have been developed to treat benign and malignant airway stenoses and tracheomalacia. And more recently, techniques have been conceived to treat end-stage emphysema and prolonged air leaks in select patients. This review describes the abundant uses of airway endoscopy, as well as technical considerations and limitations of the current technologies. PMID:26981263

  9. Using optical coherence tomography (OCT) imaging in the evaluation of airway dynamics (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    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.

  10. Real-Time 3D Magnetic Resonance Imaging of the Pharyngeal Airway in Sleep Apnea

    PubMed Central

    Kim, Yoon-Chul; Lebel, R. Marc; Wu, Ziyue; Davidson Ward, Sally L.; Khoo, Michael C.K.; Nayak, Krishna S.

    2014-01-01

    Purpose To investigate the feasibility of real-time 3D magnetic resonance imaging (MRI) with simultaneous recording of physiological signals for identifying sites of airway obstruction during natural sleep in pediatric patients with sleep-disordered breathing. Methods Experiments were performed using a three-dimensional Fourier transformation (3DFT) gradient echo sequence with prospective undersampling based on golden-angle radial spokes, and L1-norm regularized iterative self-consistent parallel imaging (L1-SPIRiT) reconstruction. This technique was demonstrated in three healthy adult volunteers and five pediatric patients with sleep-disordered breathing. External airway occlusion was used to induce partial collapse of the upper airway on inspiration and test the effectiveness of the proposed imaging method. Apneic events were identified using information available from synchronized recording of mask pressure and respiratory effort. Results Acceptable image quality was obtained in seven of eight subjects. Temporary airway collapse induced via inspiratory loading was successfully imaged in all three volunteers, with average airway volume reductions of 63.3%, 52.5%, and 33.7%. Central apneic events and associated airway narrowing/closure were identified in two pediatric patients. During central apneic events, airway obstruction was observed in the retropalatal region in one pediatric patient. Conclusion Real-time 3D MRI of the pharyngeal airway with synchronized recording of physiological signals is feasible and may provide valuable information about the sites and nature of airway narrowing/collapse during natural sleep. PMID:23788203

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

    PubMed Central

    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

  12. TRP channels and temperature in airway disease-clinical significance.

    PubMed

    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

  13. Estimating the diameter of airways susceptible for collapse using crackle sound

    PubMed Central

    Majumdar, Arnab; Hantos, Zoltán; Tolnai, József; Parameswaran, Harikrishnan; Tepper, Robert

    2009-01-01

    Airways that collapse during deflation generate a crackle sound when they reopen during subsequent reinflation. Since each crackle is associated with the reopening of a collapsed airway, the likelihood of an airway to be a crackle source is identical to its vulnerability to collapse. To investigate this vulnerability of airways to collapse, crackles were recorded during the first inflation of six excised rabbit lungs from the collapsed state, and subsequent reinflations from 5, 2, 1, and 0 cmH2O end-expiratory pressure levels. We derived a relationship between the amplitude of a crackle sound at the trachea and the generation number (n) of the source airway where the crackle was generated. Using an asymmetrical tree model of the rabbit airways with elastic walls, airway vulnerability to collapse was also determined in terms of airway diameter D. During the reinflation from end-expiratory pressure = 0 cmH2O, the most vulnerable airways were estimated to be centered at n = 12 with a peak. Vulnerability in terms of D ranged between 0.1 and 1.3 mm, with a peak at 0.3 mm. During the inflation from the collapsed state, however, vulnerability was much less localized to a particular n or D, with maximum values of n = 8 and D = 0.75 mm. Numerical simulations using a tree model that incorporates airway opening and closing support these conclusions. Thus our results indicate that there are airways of a given range of diameters that can become unstable during deflation and vulnerable to collapse and subsequent injury. PMID:19729587

  14. Computational analysis of microbubble flows in bifurcating airways: role of gravity, inertia, and surface tension.

    PubMed

    Chen, Xiaodong; Zielinski, Rachel; Ghadiali, Samir N

    2014-10-01

    Although mechanical ventilation is a life-saving therapy for patients with severe lung disorders, the microbubble flows generated during ventilation generate hydrodynamic stresses, including pressure and shear stress gradients, which damage the pulmonary epithelium. In this study, we used computational fluid dynamics to investigate how gravity, inertia, and surface tension influence both microbubble flow patterns in bifurcating airways and the magnitude/distribution of hydrodynamic stresses on the airway wall. Direct interface tracking and finite element techniques were used to simulate bubble propagation in a two-dimensional (2D) liquid-filled bifurcating airway. Computational solutions of the full incompressible Navier-Stokes equation were used to investigate how inertia, gravity, and surface tension forces as characterized by the Reynolds (Re), Bond (Bo), and Capillary (Ca) numbers influence pressure and shear stress gradients at the airway wall. Gravity had a significant impact on flow patterns and hydrodynamic stress magnitudes where Bo > 1 led to dramatic changes in bubble shape and increased pressure and shear stress gradients in the upper daughter airway. Interestingly, increased pressure gradients near the bifurcation point (i.e., carina) were only elevated during asymmetric bubble splitting. Although changes in pressure gradient magnitudes were generally more sensitive to Ca, under large Re conditions, both Re and Ca significantly altered the pressure gradient magnitude. We conclude that inertia, gravity, and surface tension can all have a significant impact on microbubble flow patterns and hydrodynamic stresses in bifurcating airways. PMID:25068642

  15. [Frostbite injuries causing compromised airway after inhalation of propane].

    PubMed

    Straarup, Therese Simonsen; Fink, Anders Olsen; Larsen, Jens Kjærgaard Rolighed

    2015-01-01

    We describe a case report of a 23-year-old man with acute pharyngeal injuries due to frostbite subsequent to inhalation of propane. He was fiber-optically intubated on admission to hospital since his airways were considered acutely compromised. He was subsequently kept intubated for 11 days due to persistent pharyngeal oedema and frostbite injuries. The latter is caused by low temperature of propane upon release from a pressurized container. Injuries caused by frostbite often gradually progress and thus caution should be exerted in regards to airway management. PMID:25557449

  16. Putting the Squeeze on Airway Epithelia.

    PubMed

    Park, Jin-Ah; Fredberg, Jeffrey J; Drazen, Jeffrey M

    2015-07-01

    Asthma is characterized by chronic inflammation, airway hyperresponsiveness, and progressive airway remodeling. The airway epithelium is known to play a critical role in the initiation and perpetuation of these processes. Here, we review how excessive epithelial stress generated by bronchoconstriction is sufficient to induce airway remodeling, even in the absence of inflammatory cells. PMID:26136543

  17. Putting the Squeeze on Airway Epithelia

    PubMed Central

    Park, Jin-Ah; Fredberg, Jeffrey J.

    2015-01-01

    Asthma is characterized by chronic inflammation, airway hyperresponsiveness, and progressive airway remodeling. The airway epithelium is known to play a critical role in the initiation and perpetuation of these processes. Here, we review how excessive epithelial stress generated by bronchoconstriction is sufficient to induce airway remodeling, even in the absence of inflammatory cells. PMID:26136543

  18. Airway clearance in neuromuscular weakness.

    PubMed

    Gauld, Leanne Maree

    2009-05-01

    Impaired airway clearance leads to recurrent chest infections and respiratory deterioration in neuromuscular weakness. It is frequently the cause of death. Cough is the major mechanism of airway clearance. Cough has several components, and assessment tools are available to measure the different components of cough. These include measuring peak cough flow, respiratory muscle strength, and inspiratory capacity. Each is useful in assessing the ability to generate an effective cough, and can be used to guide when techniques of assisting airway clearance may be effective for the individual and which are most effective. Techniques to assist airway clearance include augmenting inspiration by air stacking, augmenting expiration by assisting the cough, and augmenting both inspiration and expiration with the mechanical insufflator-exsufflator or by direct suctioning via a tracheostomy. Physiotherapists are invaluable in assisting airway clearance, and in teaching patients and their families how to use these techniques. Use of the mechanical insufflator-exsufflator has gained popularity in recent times, but several simpler, more economical methods are available to assist airway clearance that can be used effectively alone or in combination. This review examines the literature available on the assessment and management of impaired airway clearance in neuromuscular weakness. PMID:19379290

  19. Laryngeal pressure receptors.

    PubMed

    Mathew, O P; Sant'Ambrogio, G; Fisher, J T; Sant'Ambrogio, F B

    1984-07-01

    We studied the response characteristics of laryngeal pressure receptors in anesthetized dogs, breathing through a tracheal cannula, by recording single unit action potentials from the peripheral cut end of the internal branch of the superior laryngeal nerve. The larynx, with the rest of the upper airway, was isolated and cannulated separately for the application of distending and collapsing pressures. We identified receptors responding to either negative or positive pressure and a few responding to both. All these receptors showed a marked dynamic sensitivity and had the characteristics of slowly adapting mechanoreceptors. The majority of pressure receptors were active at zero transmural pressure and the gain of their response to pressure was higher at lower values, suggesting a role for these receptors in eupnea. Reflex alterations in breathing pattern and upper airway muscle activity during upper airway pressure changes, previously reported, are presumably mediated by the receptors described here. Moreover, these receptors may play a role in certain pathological states, such as obstructive sleep apnea, in which the upper airway is transiently subjected to large collapsing pressure. PMID:6484319

  20. Computational Flow Modeling of Human Upper Airway Breathing

    NASA Astrophysics Data System (ADS)

    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

  1. Irritant-induced airway disorders.

    PubMed

    Brooks, Stuart M; Bernstein, I Leonard

    2011-11-01

    Thousands of persons experience accidental high-level irritant exposures each year but most recover and few die. Irritants function differently than allergens because their actions proceed nonspecifically and by nonimmunologic mechanisms. For some individuals, the consequence of a single massive exposure to an irritant, gas, vapor or fume is persistent airway hyperresponsiveness and the clinical picture of asthma, referred to as reactive airways dysfunction syndrome (RADS). Repeated irritant exposures may lead to chronic cough and continual airway hyperresponsiveness. Cases of asthma attributed to repeated irritant-exposures may be the result of genetic and/or host factors. PMID:21978855

  2. Increased airway glucose increases airway bacterial load in hyperglycaemia

    PubMed Central

    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

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

    PubMed

    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

  4. Rare Upper Airway Anomalies.

    PubMed

    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

  5. [Reactive airways dysfunction syndrome].

    PubMed

    Costa, R; Orriols, R

    2005-01-01

    Reactive airways dysfunction syndrome, better known as RADS, was described as a clinical entity consisting in the appearance of bronchial asthma due to massive toxic inhalation. The term was coined and recognised for the first time in 1985. Since then different publications have verified new cases as well as different causal agents. It usually arises from an accident at the work place and in closed or poorly ventilated spaces, where high concentrations of irritant products are inhaled in the form of gas, smoke or vapour. In the following minutes or hours symptoms of bronchial obstruction appear in an acute form, with bronchial hyperresponsiveness persisting for months or years. The affected patients do not show a recurrence of symptoms following exposure to non-toxic doses of the same agent that started the symptoms. This is why diagnosis is based on clinical manifestations as it is not reproducible through a provocation test. PMID:15915173

  6. High-frequency oscillation of the airway and chest wall.

    PubMed

    Fink, James B; Mahlmeister, Michael J

    2002-07-01

    High-frequency oscillation (HFO), applied to either the airway or chest wall, has been associated with changes in sputum attributes and clearance. The evolution of evidence, both in vitro and in vivo, supporting the use of HFO is reviewed. Devices that apply HFO to the airway range from the relatively simple mechanical Flutter and Acapella devices to the more complex Percussionaire Intrapercussive Ventilators. and the Hayek Oscillator are designed to provide high-frequency chest wall compression. Operation and use of these devices are described with examples of differentiation of device types by characterization of flows, and airway and esophageal pressures. Although HFO devices span a broad range of costs, they provide a reasonable therapeutic option to support secretion clearance for patients with cystic fibrosis. PMID:12088550

  7. Tube Law of the Pharyngeal Airway in Sleeping Patients with Obstructive Sleep Apnea

    PubMed Central

    Genta, Pedro R.; Edwards, Bradley A.; Sands, Scott A.; Owens, Robert L.; Butler, James P.; Loring, Stephen H.; White, David P.; Wellman, Andrew

    2016-01-01

    Study Objectives: Obstructive sleep apnea (OSA) is characterized by repetitive pharyngeal collapse during sleep. However, the dynamics of pharyngeal narrowing and re-expansion during flow-limited breathing are not well described. The static pharyngeal tube law (end-expiratory area versus luminal pressure) has demonstrated increasing pharyngeal compliance as luminal pressure decreases, indicating that the airway would be sucked closed with sufficient inspiratory effort. On the contrary, the airway is rarely sucked closed during inspiratory flow limitation, suggesting that the airway is getting stiffer. Therefore, we hypothesized that during inspiratory flow limitation, as opposed to static conditions, the pharynx becomes stiffer as luminal pressure decreases. Methods: Upper airway endoscopy and simultaneous measurements of airflow and epiglottic pressure were performed during natural nonrapid eye movement sleep. Continuous positive (or negative) airway pressure was used to induce flow limitation. Flow-limited breaths were selected for airway cross-sectional area measurements. Relative airway area was quantified as a percentage of end-expiratory area. Inspiratory airway radial compliance was calculated at each quintile of epiglottic pressure versus airway area plot (tube law). Results: Eighteen subjects (14 males) with OSA (apnea-hypopnea index = 57 ± 27 events/h), aged 49 ± 8 y, with a body mass index of 35 ± 6 kg/m2 were studied. A total of 163 flow limited breaths were analyzed (9 ± 3 breaths per subject). Compliances at the fourth (2.0 ± 4.7 % area/cmH2O) and fifth (0.0 ± 1.7 % area/cmH2O) quintiles were significantly lower than the first (12.2 ± 5.5 % area/cmH2O) pressure quintile (P < 0.05). Conclusions: The pharyngeal tube law is concave (airway gets stiffer as luminal pressure decreases) during respiratory cycles under inspiratory flow limitation. Citation: Genta PR, Edwards BA, Sands SA, Owens RL, Butler JP, Loring SH, White DP, Wellman A. Tube law of

  8. CdS nanorods/organic hybrid LED array and the piezo-phototronic effect of the device for pressure mapping

    NASA Astrophysics Data System (ADS)

    Bao, Rongrong; Wang, Chunfeng; Dong, Lin; Shen, Changyu; Zhao, Kun; Pan, Caofeng

    2016-04-01

    As widely applied in light-emitting diodes and optical devices, CdS has attracted the attention of many researchers due to its nonlinear properties and piezo-electronic effect. Here, we demonstrate a LED array composed of PEDOT:PSS and CdS nanorods and research the piezo-photonic effect of the array device. The emission intensity of the device depends on the electron-hole recombination at the interface of the p-n junction which can be adjusted using the piezo-phototronic effect and can be used to map the pressure applied on the surface of the device with spatial resolution as high as 1.5 μm. A flexible LED device array has been prepared using a CdS nanorod array on a Au/Cr/kapton substrate. This device may be used in the field of strain mapping using its high pressure spatial-resolution and flexibility.As widely applied in light-emitting diodes and optical devices, CdS has attracted the attention of many researchers due to its nonlinear properties and piezo-electronic effect. Here, we demonstrate a LED array composed of PEDOT:PSS and CdS nanorods and research the piezo-photonic effect of the array device. The emission intensity of the device depends on the electron-hole recombination at the interface of the p-n junction which can be adjusted using the piezo-phototronic effect and can be used to map the pressure applied on the surface of the device with spatial resolution as high as 1.5 μm. A flexible LED device array has been prepared using a CdS nanorod array on a Au/Cr/kapton substrate. This device may be used in the field of strain mapping using its high pressure spatial-resolution and flexibility. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00431h

  9. Apoptosis and the Airway Epithelium

    PubMed Central

    White, Steven R.

    2011-01-01

    The airway epithelium functions as a barrier and front line of host defense in the lung. Apoptosis or programmed cell death can be elicited in the epithelium as a response to viral infection, exposure to allergen or to environmental toxins, or to drugs. While apoptosis can be induced via activation of death receptors on the cell surface or by disruption of mitochondrial polarity, epithelial cells compared to inflammatory cells are more resistant to apoptotic stimuli. This paper focuses on the response of airway epithelium to apoptosis in the normal state, apoptosis as a potential regulator of the number and types of epithelial cells in the airway, and the contribution of epithelial cell apoptosis in important airways diseases. PMID:22203854

  10. Extraglottic airway devices: A review

    PubMed Central

    Ramaiah, Ramesh; Das, Debasmita; Bhananker, Sanjay M; Joffe, Aaron M

    2014-01-01

    Extraglottic airway devices (EAD) have become an integral part of anesthetic care since their introduction into clinical practice 25 years ago and have been used safely hundreds of millions of times, worldwide. They are an important first option for difficult ventilation during both in-hospital and out-of-hospital difficult airway management and can be utilized as a conduit for tracheal intubation either blindly or assisted by another technology (fiberoptic endoscopy, lightwand). Thus, the EAD may be the most versatile single airway technique in the airway management toolbox. However, despite their utility, knowledge regarding specific devices and the supporting data for their use is of paramount importance to patient's safety. In this review, number of commercially available EADs are discussed and the reported benefits and potential pitfalls are highlighted. PMID:24741502

  11. United airway disease: current perspectives

    PubMed Central

    Giavina-Bianchi, Pedro; Aun, Marcelo Vivolo; Takejima, Priscila; Kalil, Jorge; Agondi, Rosana Câmara

    2016-01-01

    Upper and lower airways are considered a unified morphological and functional unit, and the connection existing between them has been observed for many years, both in health and in disease. There is strong epidemiologic, pathophysiologic, and clinical evidence supporting an integrated view of rhinitis and asthma: united airway disease in the present review. The term “united airway disease” is opportune, because rhinitis and asthma are chronic inflammatory diseases of the upper and lower airways, which can be induced by allergic or nonallergic reproducible mechanisms, and present several phenotypes. Management of rhinitis and asthma must be jointly carried out, leading to better control of both diseases, and the lessons of the Allergic Rhinitis and Its Impact on Asthma initiative cannot be forgotten. PMID:27257389

  12. Tachykinin receptors and airway pathophysiology.

    PubMed

    Maggi, C A

    1993-05-01

    The mammalian tachykinins (TKs), substance P and neurokinin A, are present in sensory nerve fibres in the upper and lower airways of various mammalian species, including humans. TKs are released from these afferent nerves in an "efferent" mode at peripheral level, especially in response to irritant stimuli. TKs exert a variety of biological effects (bronchoconstriction, plasma protein extravasation, stimulation of mucus secretion), collectively known as "neurogenic inflammation", and this process is thought to be of potential pathogenic relevance for various airway diseases. The recent development of potent and selective TK receptor antagonists on the one hand provides important new tools for the understanding of basic airway physiology and pathophysiology and, on the other, opens new possibilities for therapy of airway diseases. PMID:8390944

  13. Eosinophilic phenotypes of airway disease.

    PubMed

    Pavord, Ian D

    2013-12-01

    Our understanding of the clinical implications of eosinophilic airway inflammation has increased significantly over the last 20 years, aided by the development of noninvasive means to assess it. This pattern of airway inflammation can occur in a diverse range of airway diseases. It is associated with a positive response to corticosteroids and a high risk of preventable exacerbations. Our new understanding of the role of eosinophilic airway inflammation has paved the way for the clinical development of a number of more specific inhibitors that may become new treatment options. Different definitions, ideas of disease, and adoption of biomarkers that are not well known are necessary to fully realize the potential of these treatments. PMID:24313765

  14. Imaging of the Distal Airways

    PubMed Central

    Tashkin, Donald P.; de Lange, Eduard E.

    2009-01-01

    Imaging techniques of the lung continues to advance with improving ability to image the more distal airways. Two imaging techniques are reviewed, computerized tomography and magnetic resonance with hyperpolarized helium-3. PMID:19962040

  15. The Virtual Pediatric Airways Workbench.

    PubMed

    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

  16. Airway and Parenchymal Strains during Bronchoconstriction in the Precision Cut Lung Slice

    PubMed Central

    Hiorns, Jonathan E.; Bidan, Cécile M.; Jensen, Oliver E.; Gosens, Reinoud; Kistemaker, Loes E. M.; Fredberg, Jeffrey J.; Butler, Jim P.; Krishnan, Ramaswamy; Brook, Bindi S.

    2016-01-01

    The precision-cut lung slice (PCLS) is a powerful tool for studying airway reactivity, but biomechanical measurements to date have largely focused on changes in airway caliber. Here we describe an image processing tool that reveals the associated spatio-temporal changes in airway and parenchymal strains. Displacements of sub-regions within the PCLS are tracked in phase-contrast movies acquired after addition of contractile and relaxing drugs. From displacement maps, strains are determined across the entire PCLS or along user-specified directions. In a representative mouse PCLS challenged with 10−4M methacholine, as lumen area decreased, compressive circumferential strains were highest in the 50 μm closest to the airway lumen while expansive radial strains were highest in the region 50–100 μm from the lumen. However, at any given distance from the airway the strain distribution varied substantially in the vicinity of neighboring small airways and blood vessels. Upon challenge with the relaxant agonist chloroquine, although most strains disappeared, residual positive strains remained a long time after addition of chloroquine, predominantly in the radial direction. Taken together, these findings establish strain mapping as a new tool to elucidate local dynamic mechanical events within the constricting airway and its supporting parenchyma. PMID:27559314

  17. Airway and Parenchymal Strains during Bronchoconstriction in the Precision Cut Lung Slice.

    PubMed

    Hiorns, Jonathan E; Bidan, Cécile M; Jensen, Oliver E; Gosens, Reinoud; Kistemaker, Loes E M; Fredberg, Jeffrey J; Butler, Jim P; Krishnan, Ramaswamy; Brook, Bindi S

    2016-01-01

    The precision-cut lung slice (PCLS) is a powerful tool for studying airway reactivity, but biomechanical measurements to date have largely focused on changes in airway caliber. Here we describe an image processing tool that reveals the associated spatio-temporal changes in airway and parenchymal strains. Displacements of sub-regions within the PCLS are tracked in phase-contrast movies acquired after addition of contractile and relaxing drugs. From displacement maps, strains are determined across the entire PCLS or along user-specified directions. In a representative mouse PCLS challenged with 10(-4)M methacholine, as lumen area decreased, compressive circumferential strains were highest in the 50 μm closest to the airway lumen while expansive radial strains were highest in the region 50-100 μm from the lumen. However, at any given distance from the airway the strain distribution varied substantially in the vicinity of neighboring small airways and blood vessels. Upon challenge with the relaxant agonist chloroquine, although most strains disappeared, residual positive strains remained a long time after addition of chloroquine, predominantly in the radial direction. Taken together, these findings establish strain mapping as a new tool to elucidate local dynamic mechanical events within the constricting airway and its supporting parenchyma. PMID:27559314

  18. Impending Complete Airway Obstruction from a Reinforced Orotracheal Tube: a Case Report.

    PubMed

    Hosseinzadeh, Nima; Samadi, Shahram; Jafari Javid, Mihan; Takzare, Alireza

    2015-01-01

    Reinforced tubes are commonly used to minimize the opportunity of upper airway obstruction in patients at risk. There are a few reports of the airway obstruction resulted from kinked reinforced tubes. This report describes the obstruction of a reinforced tube in an adult patient who underwent tonsillectomy. Under general anesthesia; an armoured endotracheal tube was inserted into the trachea uneventfully. A few minutes after starting the surgery, the anesthesia machine detected a high airway pressure and an increased ETCO2 (end-tidal CO2) up to 50 mmHg. Further evaluation showed spiral wire damage resulted from Mouth Gag device that led to airway obstruction. Early anticipation of the complications leads to proper management of such critical and life threatening complications and prevention of hypoxia, hypercapnia, pneumothorax, and pulmonary edema. Based on our experience using an armoured endotracheal tube in tonsillectomy does not guarantee a safe airway and intensive monitoring is necessary. PMID:26553090

  19. Modeling and mapping the effects of heat and pressure outside a SAGD steam chamber using time-lapse multicomponent seismic data, Athabasca oil sands, Alberta

    NASA Astrophysics Data System (ADS)

    Zeigler, Loren Michelle

    The field of study is a bitumen producing reservoir within the McMurray Formation. The deposit is a part of the Athabasca oil sands trend in Northeastern Alberta, Canada. This field contains 16 well pads that are, combined, producing more than 41,000 BOPD. Bitumen reservoirs are unique as a result of their high viscosity, low API gravity oil. This oil in this field has been produced by means of a method called Steam Assisted Gravity Drainage (SAGD), since 2007. In this method, two vertically stacked, horizontal wells are drilled. The upper well injects high temperature, high pressure steam and as the viscosity of the bitumen decreases it will begin to flow, via gravity, down to the lower producing well. Reservoir monitoring in this field is very important for multiple reasons, including the shallow depth and the large velocity changes that result from SAGD production. In order to map these changes, time-lapse multicomponent data were incorporated with rock physics modeling in order to map and interpret changes in Vp/Vs with production. When fluid substitution results and pressure estimations are combined, the resulting velocities are consistent with the core sample modeling done by Kato et al. (2008). These results were then compared with the seismic data in order to identify areas affected by steam, heat, and pressure within the reservoir through time-lapse Vp/Vs. PP time-lapse results show the location of the steam chamber within the reservoir, however these data do not give any information about the effects of pressure or heat. Converted-wave (PS) data can be used to image pressure and viscosity changes in the reservoir. When these data are combined into a Vp/Vs volume, the effects of steam, heat and pressure can be identified. Vp/Vs areas of little to no difference indicate steamed zones while the surrounding areas with large differences indicate heated and pressured zones.

  20. Airway Surface Mycosis in Chronic Th2-Associated Airway Disease

    PubMed Central

    Porter, Paul; Lim, Dae Jun; Maskatia, Zahida Khan; Mak, Garbo; Tsai, Chu-Lin; Citardi, Martin J; Fakhri, Samer; Shaw, Joanne L.; Fothergil, Annette; Kheradmand, Farrah; Corry, David B; Luong, Amber

    2014-01-01

    Background Environmental fungi have been linked to T helper type 2 (Th2) cell-related airway inflammation and the Th2-associated chronic airway diseases asthma, chronic rhinosinusitis with nasal polyps (CRSwNP) and allergic fungal rhinosinusitis (AFRS), but whether these organisms participate directly or indirectly in disease pathology remains unknown. Objective To determine the frequency of fungus isolation and fungus-specific immunity in Th2-associated and non-associated airway disease patients. Methods Sinus lavage fluid and blood were collected from sinus surgery patients (n=118) including CRS patients with and without nasal polyps and AFRS and non-CRS/non-asthmatic control patients. Asthma status was deteremined from medical history. Sinus lavage fluids were cultured and directly examined for evidence of viable fungi. Peripheral blood mononuclear cells were restimulated with fungal antigens in an enzyme linked immunocell spot (ELISpot) assay to determine total memory fungus-specific IL-4-secreting cells. These data were compared to fungus-specific IgE levels measured from plasma by ELISA. Results Filamentous fungi were significantly more commonly cultured from Th2-associated airway disease subjects (asthma, CRSwNP, or AFRS: n=68) compared to non-Th2-associated control patients (n=31); 74% vs 16% respectively, p<0.001. Both fungus-specific IL-4 ELISpot (n=48) and specific IgE (n=70) data correlated with Th2-associated diseases (sensitivity 73% and specificity 100% vs. 50% and 77%, respectively). Conclusions The frequent isolation of fungi growing directly within the airways accompanied by specific immunity to these organisms only in patients with Th2-associated chronic airway diseases suggests that fungi participate directly in the pathogenesis of these conditions. Efforts to eradicate airway fungi from the airways should be considered in selected patients. Clinical Implications Airway fungi may contribute to the expression of sinusitis with nasal polyps and

  1. IL-6 trans-signaling increases expression of airways disease genes in airway smooth muscle.

    PubMed

    Robinson, Mac B; Deshpande, Deepak A; Chou, Jeffery; Cui, Wei; Smith, Shelly; Langefeld, Carl; Hastie, Annette T; Bleecker, Eugene R; Hawkins, Gregory A

    2015-07-15

    Genetic data suggest that IL-6 trans-signaling may have a pathogenic role in the lung; however, the effects of IL-6 trans-signaling on lung effector cells have not been investigated. In this study, human airway smooth muscle (HASM) cells were treated with IL-6 (classical) or IL-6+sIL6R (trans-signaling) for 24 h and gene expression was measured by RNAseq. Intracellular signaling and transcription factor activation were assessed by Western blotting and luciferase assay, respectively. The functional effect of IL-6 trans-signaling was determined by proliferation assay. IL-6 trans-signaling had no effect on phosphoinositide-3 kinase and Erk MAP kinase pathways in HASM cells. Both classical and IL-6 trans-signaling in HASM involves activation of Stat3. However, the kinetics of Stat3 phosphorylation by IL-6 trans-signaling was different than classical IL-6 signaling. This was further reflected in the differential gene expression profile by IL-6 trans-signaling in HASM cells. Under IL-6 trans-signaling conditions 36 genes were upregulated, including PLA2G2A, IL13RA1, MUC1, and SOD2. Four genes, including CCL11, were downregulated at least twofold. The expression of 112 genes was divergent between IL-6 classical and trans-signaling, including the genes HILPDA, NNMT, DAB2, MUC1, WWC1, and VEGFA. Pathway analysis revealed that IL-6 trans-signaling induced expression of genes involved in regulation of airway remodeling, immune response, hypoxia, and glucose metabolism. Treatment of HASM cells with IL-6+sIL6R induced proliferation in a dose-dependent fashion, suggesting a role for IL-6 trans-signaling in asthma pathogenesis. These novel findings demonstrate differential effect of IL-6 trans-signaling on airway cells and identify IL-6 trans-signaling as a potential modifier of airway inflammation and remodeling. PMID:26001777

  2. Tachykinin antagonists and the airways.

    PubMed

    Joos, G F; Kips, J C; Peleman, R A; Pauwels, R A

    1995-01-01

    There is now convincing evidence for the presence of substance P (SP) and neurokinin A (NKA) in human airway nerves. Studies on autopsy tissue, on bronchoalveolar lavage fluid and on sputum suggest that SP may be present in increased amounts in the asthmatic airway. Substance P and NKA are potent bronchoconstrictors of human airways, asthmatics being more sensitive than normal persons. The major enzyme responsible for the degradation of the tachykinins, the neutral endopeptidase, is present in the airways and is involved in the breakdown of exogenously administered SP and NKA, both in normal and asthmatic persons. Other, less well documented airway effects of SP and NKA include mucus secretion, vasodilation and plasma extravasation, as well as the chemoattraction and stimulation of various cells presumed to be involved in asthmatic airway inflammation. NK2 receptors and, to a lesser extent, NK1 receptors have been shown to be involved in bronchoconstriction, whereas NK1 receptors were found to be involved in mucus secretion, microvascular leakage and vasodilatation, and in most of the effects on inflammatory cells. The first clinical trial with FK224, a peptide NK1 and NK2 receptor antagonist, and CP99994, a nonpeptide NK1 receptor antagonist, are negative. However, FK224 failed to block the bronchoconstrictor effect of NKA in asthmatics and the dose of CP99994, needed to antagonize tachykinin effects in man, remains to be determined. PMID:7543746

  3. Surfactant and allergic airway inflammation.

    PubMed

    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

  4. Upper Airway Genioglossal Activity in Children with Sickle Cell Disease

    PubMed Central

    Huang, Jingtao; Pinto, Swaroop J.; Allen, Julian L.; Arens, Raanan; Bowdre, Cheryl Y.; Jawad, Abbas F.; Mason, Thornton B.A.; Ohene-Frempong, Kwaku; Smith-Whitley, Kim; Marcus, Carole L.

    2011-01-01

    Study Objectives: The prevalence of obstructive sleep apnea syndrome (OSAS) in sickle cell disease (SCD) has been reported to be higher than that in the general pediatric population. However, not all subjects with SCD develop OSAS. We hypothesized that SCD patients with OSAS have a blunted neuromuscular response to subatmospheric pressure loads during sleep, making them more likely to develop upper airway collapse. Design: Subjects with SCD with and without OSAS underwent pressure-flow measurements during sleep using intraoral surface electrodes to measure genioglossal EMG (EMGgg). Two techniques were applied to decrease the nasal pressure (PN) to subatmospheric levels, resulting in an activated and relatively hypotonic upper airway. The area under the curve of the inspiratory EMGgg moving time average was analyzed. EMGgg activity was expressed as a percentage of baseline. Changes in EMGgg in response to decrements in nasal pressure were expressed as the slope of the EMGgg vs. nasal pressure (slope of EMGgg-PN). Setting: Sleep laboratory. Participants: 4 children with SCD and OSAS and 18 children with SCD but without OSAS. Results: The major findings of this study were: (1) using the activated but not the hypotonic technique, the slope of EMGgg-PN was more negative in SCD controls than SCD OSAS; (2) the slope of EMGgg-PN was significantly lower using the activated technique compared to the hypotonic technique in SCD controls only; (3) similarly, the critical closing pressure, Pcrit, was more negative using the activated technique than the hypotonic technique in SCD controls but not in SCD OSAS. Conclusion: This preliminary study has shown that children with SCD but without OSAS have more prominent upper airway reflexes than children with SCD and OSAS. Citation: Huang J; Pinto SJ; Allen JL; Arens R; Bowdre CY; Jawad AF; Mason TBA; Ohene-Frempong K; Smith-Whitely K; Marcus CL. Upper airway genioglossal activity in children with sickle cell disease. SLEEP 2011

  5. Supra-Epiglottic Upper Airway Volume in Elderly Patients with Obstructive Sleep Apnea Hypopnea Syndrome

    PubMed Central

    Abdirahman Mohamed Moussa, Syad; Celle, Sébastien; Laurent, Bernard; Barthélémy, Jean-Claude; Barral, Fabrice-Guy; Roche, Frédéric

    2016-01-01

    Objective Small upper airway measurements areas and high body mass index are recognized risk factors for obstructive sleep apnea syndrome (OSAS) in non-elderly populations; however, there is limited information regarding elderly patients. We evaluated whether upper airway volume is associated with OSAS and OSAS treated with continuous positive airway pressure (CPAP) treatment and whether BMI is correlated with upper airway volume and measurements in elderly subjects. Methods In 60 volunteers aged 75.58±0.9 years: 20 OSAS, 20 OSAS chronically treated with CPAP, and 20 controls, semi-automatic segmentation, retropalatal distance and transverse diameter of the supra-epiglottic upper airway were evaluated using 3DT1-weighted magnetic resonance imaging. Anteroposterior to transverse diameter ratio was defined as retropalatar diameter/transverse diameter. Results There were no significant differences in supra-epiglottic upper airway volume between OSAS, CPAP treated patients, and controls. There were significant differences in retropalatal distance and anteroposterior to transverse diameter ratio between OSAS, CPAP treated patients, and controls (P = 0.008 and P<0.0001 respectively). There was a significant correlation between body mass index and retropalatal distance (P<0.05) but not with supra-epiglottic upper airway volume. Conclusion In elderly subjects, OSAS and body mass index are not associated with changes in supra-epiglottic upper airway volume but are associated with modification of pharynx shape. PMID:27336305

  6. Kinematic MRI study of upper-airway biomechanics using electrical muscle stimulation

    NASA Astrophysics Data System (ADS)

    Brennick, Michael J.; Margulies, Susan S.; Ford, John C.; Gefter, Warren B.; Pack, Allan I.

    1997-05-01

    We have developed a new and powerful method to study the movement and function of upper airway muscles. Our method is to use direct electrical stimulation of individual upper airway muscles, while performing state of the art high resolution magnetic resonance imaging (MRI). We have adapted a paralyzed isolated UA cat model so that positive or negative static pressure in the UA can be controlled at specific levels while electrical muscle stimulation is applied during MRI. With these techniques we can assess the effect of muscle stimulation on airway cross-sectional area compliance and soft tissue motion. We are reporting the preliminary results and MRI techniques which have enabled us to examine changes in airway dimensions which result form electrical stimulation of specific upper airway dilator muscles. The results of this study will be relevant to the development of new clinical treatments for obstructive sleep apnea by providing new information as to exactly how upper airway muscles function to dilate the upper airway and the strength of stimulation required to prevent the airway obstruction when overall muscle tone may not be sufficient to maintain regular breathing.

  7. On locating the obstruction in the human upper airway

    NASA Astrophysics Data System (ADS)

    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).

  8. A model of surfactant-induced surface tension effects on the parenchymal tethering of pulmonary airways.

    PubMed

    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

  9. Human airway ciliary dynamics

    PubMed Central

    Thompson, Kristin; Knowles, Michael R.; Davis, C. William

    2013-01-01

    Airway cilia depend on precise changes in shape to transport the mucus gel overlying mucosal surfaces. The ciliary motion can be recorded in several planes using video microscopy. However, cilia are densely packed, and automated computerized systems are not available to convert these ciliary shape changes into forms that are useful for testing theoretical models of ciliary function. We developed a system for converting planar ciliary motions recorded by video microscopy into an empirical quantitative model, which is easy to use in validating mathematical models, or in examining ciliary function, e.g., in primary ciliary dyskinesia (PCD). The system we developed allows the manipulation of a model cilium superimposed over a video of beating cilia. Data were analyzed to determine shear angles and velocity vectors of points along the cilium. Extracted waveforms were used to construct a composite waveform, which could be used as a standard. Variability was measured as the mean difference in position of points on individual waveforms and the standard. The shapes analyzed were the end-recovery, end-effective, and fastest moving effective and recovery with mean (± SE) differences of 0.31(0.04), 0.25(0.06), 0.50(0.12), 0.50(0.10), μm, respectively. In contrast, the same measures for three different PCD waveforms had values far outside this range. PMID:23144323

  10. Role of Small Airways in Asthma.

    PubMed

    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

  11. Simulation of turbulent airflow using a CT based upper airway model of a racehorse.

    PubMed

    Rakesh, Vineet; Datta, Ashim K; Ducharme, Normand G; Pease, Anthony P

    2008-06-01

    Computational model for airflow through the upper airway of a horse was developed. Previous flow models for human airway do not hold true for horses due to significant differences in anatomy and the high Reynolds number of flow in the equine airway. Moreover, models that simulate the entire respiratory cycle and emphasize on pressures inside the airway in relation to various anatomical diseases are lacking. The geometry of the airway was created by reconstructing images obtained from computed tomography scans of a thoroughbred racehorse. Different geometries for inhalation and exhalation were used for the model based on the difference in the nasopharynx size during the two phases of respiration. The Reynolds averaged Navier-Stokes equations were solved for the isothermal flow with the standard k-epsilon model for turbulence. Transient pressure boundary conditions for the entire breathing cycle were obtained from past experimental studies on live horses. The flow equations were solved in a commercial finite volume solver. The flow rates, computed based on the applied pressure conditions, were compared to experimentally measured flow rates for model validation. Detailed analysis of velocity, pressure, and turbulence characteristics of the flow was done. Velocity magnitudes at various slices during inhalation were found to be higher than corresponding velocity magnitudes during exhalation. The front and middle parts of the nasopharynx were found to have minimum intraluminal pressure in the airway during inhalation. During exhalation, the pressures in the soft palate were higher compared to those in the larynx, epiglottis, and nasopharynx. Turbulent kinetic energy was found to be maximum at the entry to the airway and gradually decreased as the flow moved inside the airway. However, turbulent kinetic energy increased in regions of the airway with abrupt change in area. Based on the analysis of pressure distribution at different sections of the airway, it was concluded

  12. Mechanics of airway and alveolar collapse in human breath-hold diving.

    PubMed

    Fitz-Clarke, John R

    2007-11-15

    A computational model of the human respiratory tract was developed to study airway and alveolar compression and re-expansion during deep breath-hold dives. The model incorporates the chest wall, supraglottic airway, trachea, branched airway tree, and elastic alveoli assigned time-dependent surfactant properties. Total lung collapse with degassing of all alveoli is predicted to occur around 235 m, much deeper than estimates for aquatic mammals. Hysteresis of the pressure-volume loop increases with maximum diving depth due to progressive alveolar collapse. Reopening of alveoli occurs stochastically as airway pressure overcomes adhesive and compressive forces on ascent. Surface area for gas exchange vanishes at collapse depth, implying that the risk of decompression sickness should reach a plateau beyond this depth. Pulmonary capillary transmural stresses cannot increase after local alveolar collapse. Consolidation of lung parenchyma might provide protection from capillary injury or leakage caused by vascular engorgement due to outward chest wall recoil at extreme depths. PMID:17827075

  13. Blockage of upper airway

    MedlinePlus

    ... closed, including allergic reactions to a bee sting , peanuts, antibiotics (such as penicillin), and blood pressure medicines ( ... from breathing in smoke Foreign bodies, such as peanuts and other breathed-in foods, pieces of a ...

  14. Airway Gland Structure and Function.

    PubMed

    Widdicombe, Jonathan H; Wine, Jeffrey J

    2015-10-01

    Submucosal glands contribute to airway surface liquid (ASL), a film that protects all airway surfaces. Glandular mucus comprises electrolytes, water, the gel-forming mucin MUC5B, and hundreds of different proteins with diverse protective functions. Gland volume per unit area of mucosal surface correlates positively with impaction rate of inhaled particles. In human main bronchi, the volume of the glands is ∼ 50 times that of surface goblet cells, but the glands diminish in size and frequency distally. ASL and its trapped particles are removed from the airways by mucociliary transport. Airway glands have a tubuloacinar structure, with a single terminal duct, a nonciliated collecting duct, then branching secretory tubules lined with mucous cells and ending in serous acini. They allow for a massive increase in numbers of mucus-producing cells without replacing surface ciliated cells. Active secretion of Cl(-) and HCO3 (-) by serous cells produces most of the fluid of gland secretions. Glands are densely innervated by tonically active, mutually excitatory airway intrinsic neurons. Most gland mucus is secreted constitutively in vivo, with large, transient increases produced by emergency reflex drive from the vagus. Elevations of [cAMP]i and [Ca(2+)]i coordinate electrolyte and macromolecular secretion and probably occur together for baseline activity in vivo, with cholinergic elevation of [Ca(2+)]i being mainly responsive for transient increases in secretion. Altered submucosal gland function contributes to the pathology of all obstructive diseases, but is an early stage of pathogenesis only in cystic fibrosis. PMID:26336032

  15. The Airway Microbiome at Birth

    PubMed Central

    Lal, Charitharth Vivek; Travers, Colm; Aghai, Zubair H.; Eipers, Peter; Jilling, Tamas; Halloran, Brian; Carlo, Waldemar A.; Keeley, Jordan; Rezonzew, Gabriel; Kumar, Ranjit; Morrow, Casey; Bhandari, Vineet; Ambalavanan, Namasivayam

    2016-01-01

    Alterations of pulmonary microbiome have been recognized in multiple respiratory disorders. It is critically important to ascertain if an airway microbiome exists at birth and if so, whether it is associated with subsequent lung disease. We found an established diverse and similar airway microbiome at birth in both preterm and term infants, which was more diverse and different from that of older preterm infants with established chronic lung disease (bronchopulmonary dysplasia). Consistent temporal dysbiotic changes in the airway microbiome were seen from birth to the development of bronchopulmonary dysplasia in extremely preterm infants. Genus Lactobacillus was decreased at birth in infants with chorioamnionitis and in preterm infants who subsequently went on to develop lung disease. Our results, taken together with previous literature indicating a placental and amniotic fluid microbiome, suggest fetal acquisition of an airway microbiome. We speculate that the early airway microbiome may prime the developing pulmonary immune system, and dysbiosis in its development may set the stage for subsequent lung disease. PMID:27488092

  16. Allergen-induced airway responses.

    PubMed

    Gauvreau, Gail M; El-Gammal, Amani I; O'Byrne, Paul M

    2015-09-01

    Environmental allergens are an important cause of asthma and can contribute to loss of asthma control and exacerbations. Allergen inhalation challenge has been a useful clinical model to examine the mechanisms of allergen-induced airway responses and inflammation. Allergen bronchoconstrictor responses are the early response, which reaches a maximum within 30 min and resolves by 1-3 h, and late responses, when bronchoconstriction recurs after 3-4 h and reaches a maximum over 6-12 h. Late responses are followed by an increase in airway hyperresponsiveness. These responses occur when IgE on mast cells is cross-linked by an allergen, causing degranulation and the release of histamine, neutral proteases and chemotactic factors, and the production of newly formed mediators, such as cysteinyl leukotrienes and prostaglandin D2. Allergen-induced airway inflammation consists of an increase in airway eosinophils, basophils and, less consistently, neutrophils. These responses are mediated by the trafficking and activation of myeloid dendritic cells into the airways, probably as a result of the release of epithelial cell-derived thymic stromal lymphopoietin, and the release of pro-inflammatory cytokines from type 2 helper T-cells. Allergen inhalation challenge has also been a widely used model to study potential new therapies for asthma and has an excellent negative predictive value for this purpose. PMID:26206871

  17. The Airway Microbiome at Birth.

    PubMed

    Lal, Charitharth Vivek; Travers, Colm; Aghai, Zubair H; Eipers, Peter; Jilling, Tamas; Halloran, Brian; Carlo, Waldemar A; Keeley, Jordan; Rezonzew, Gabriel; Kumar, Ranjit; Morrow, Casey; Bhandari, Vineet; Ambalavanan, Namasivayam

    2016-01-01

    Alterations of pulmonary microbiome have been recognized in multiple respiratory disorders. It is critically important to ascertain if an airway microbiome exists at birth and if so, whether it is associated with subsequent lung disease. We found an established diverse and similar airway microbiome at birth in both preterm and term infants, which was more diverse and different from that of older preterm infants with established chronic lung disease (bronchopulmonary dysplasia). Consistent temporal dysbiotic changes in the airway microbiome were seen from birth to the development of bronchopulmonary dysplasia in extremely preterm infants. Genus Lactobacillus was decreased at birth in infants with chorioamnionitis and in preterm infants who subsequently went on to develop lung disease. Our results, taken together with previous literature indicating a placental and amniotic fluid microbiome, suggest fetal acquisition of an airway microbiome. We speculate that the early airway microbiome may prime the developing pulmonary immune system, and dysbiosis in its development may set the stage for subsequent lung disease. PMID:27488092

  18. Numerical simulation of soft palate movement and airflow in human upper airway by fluid-structure interaction method

    NASA Astrophysics Data System (ADS)

    Sun, Xiuzhen; Yu, Chi; Wang, Yuefang; Liu, Yingxi

    2007-08-01

    In this paper, the authors present airflow field characteristics of human upper airway and soft palate movement attitude during breathing. On the basis of the data taken from the spiral computerized tomography images of a healthy person and a patient with Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS), three-dimensional models of upper airway cavity and soft palate are reconstructed by the method of surface rendering. Numerical simulation is performed for airflow in the upper airway and displacement of soft palate by fluid-structure interaction analysis. The reconstructed three-dimensional models precisely preserve the original configuration of upper airways and soft palate. The results of the pressure and velocity distributions in the airflow field are quantitatively determined, and the displacement of soft palate is presented. Pressure gradients of airway are lower for the healthy person and the airflow distribution is quite uniform in the case of free breathing. However, the OSAHS patient remarkably escalates both the pressure and velocity in the upper airway, and causes higher displacement of the soft palate. The present study is useful in revealing pathogenesis and quantitative mutual relationship between configuration and function of the upper airway as well as in diagnosing diseases related to anatomical structure and function of the upper airway.

  19. Pressure mapping for sphere and half-sphere enhanced diamond anvil cells using synchrotron x-ray diffraction and fluorescence techniques

    NASA Astrophysics Data System (ADS)

    Liu, H.; Liu, L. L.; Cai, Z.; Shu, J.

    2015-12-01

    The measurement for equation of state (EoS) of materials under pressure conditions above 200 GPa is a long-standing challenging subject. Recently, second stage anvil, which was loaded inside the diamond anvil cell (DAC), had been reported by various groups. This method could generate pressure over 300 GPa, or above 600 GPa from the EoS measurement of Re metal between the tiny anvil or 2 half-spheres. Several alternative approaches, using ruby balls, or glassy carbon, or diamond, with single sphere, 2 half-spheres, or multi spheres geometry inside DAC, were tested. The NIST X-ray powder standard, ZnO was selected as pressure marker. Focused ion beam (FIB) was used to cut the half-sphere from diamond anvil top directly to avoid the difficulty of alignment. The synchrotron x-ray diffraction with fine beam size down to 100 nm using zone plate set-up was used to map the pressure gradient at the sphere or half-sphere zone inside DAC. The pressure could be boosted at center of sphere by up to 10 - 70 GPa at about 200 GPa conditions. From broken anvils, trace element analysis using fine focusing synchrotron x-ray fluorescence method revealed the potential anvil damage from FIB cutting the diamond anvil tip, which might decrease the strength of anvils. Fine touch from FIB cutting at final stage using low ion beam current is suggested.

  20. Raman and photoluminescence mapping of InxGa1-xN (x ˜ 0.4) at high pressure: Optical determination of composition and stress

    NASA Astrophysics Data System (ADS)

    Gkrana, V.; Filintoglou, K.; Arvanitidis, J.; Christofilos, D.; Bazioti, C.; Dimitrakopulos, G. P.; Katsikini, M.; Ves, S.; Kourouklis, G. A.; Zoumakis, N.; Georgakilas, A.; Iliopoulos, E.

    2014-09-01

    The pressure response of a polar wurtzite InxGa1-xN (x = 0.37) film epitaxially grown on a GaN/sapphire template was studied by means of combined Raman and photoluminescence (PL) mappings. The pressure slopes of the Raman peaks (∂ω/∂P ˜ 4.7 cm-1.GPa-1) of the studied alloy are indicative of its intermediate stiffness between the end members of the InxGa1-xN system. The data analysis suggests that in our experiments the obtained slopes have marginal contribution, if any, from the substrate. Furthermore, the similarity of the ambient pressure value of the PL peak energy (˜1.97 eV) and its pressure slope (∂EPL/∂P ˜ 30 meV.GPa-1) with those obtained by absorption measurements implies that PL can be used to follow the pressure evolution of the energy bandgap. Finally, we demonstrate that all-optical characterization of the composition and residual stress of InxGa1-xN samples is feasible.

  1. [Orthodontics and the upper airway].

    PubMed

    Cobo Plana, J; de Carlos Villafranca, F; Macías Escalada, E

    2004-03-01

    One of the general aims of orthodontic treatment and of the combination of orthodontics and orthognathic surgery is to achieve good occlusion and aesthetic improvement, especially in cases of severe dentoskeletal deformities. However, on many occasions, the parameters of the upper airways are not taken into account when the aims of conventional treatment are fulfilled. Patients with obstructive alterations during sleep represent for the orthodontist a type of patient who differs from the normal; for them, treatment should include the objective of improving oxygen saturation. Here, functional considerations should outweigh purely aesthetic ones. It is important, when making an orthodontic, surgical or combined diagnosis for a patient, to bear in mind the impact that treatment may have on the upper airways. Good aesthetics should never be achieved for some of our patients at the expense of diminishing the capacity of their upper airways. PMID:15301356

  2. Comparative Efficacy of the Air-Q Intubating Laryngeal Airway during General Anesthesia in Pediatric Patients: A Systematic Review and Meta-Analysis

    PubMed Central

    Ahn, Eun Jin; Choi, Geun Joo; Kang, Hyun; Baek, Chong Wha; Jung, Yong Hun; Woo, Young Cheol; Bang, Si Ra

    2016-01-01

    Air-Q® (air-Q) is a supraglottic airway device which can be used as a guidance of intubation in pediatric as well as in adult patients. We evaluated the efficacy and safety of air-Q compared to other airway devices during general anesthesia in pediatric patients by conducting a systematic review and meta-analysis. A total of 10 studies including 789 patients were included in the final analysis. Compared with other supraglottic airway devices, air-Q showed no evidence for a difference in leakage pressure and insertion time. The ease of insertion was significantly lower than other supraglottic airway devices. The success rate of intubation was significantly lower than other airway devices. However, fiberoptic view was better through the air-Q than other supraglottic airway devices. Therefore, air-Q could be a safe substitute for other airway devices and may provide better fiberoptic bronchoscopic view. PMID:27419134

  3. Airway surface liquid volume expansion induces rapid changes in amiloride-sensitive Na+ transport across upper airway epithelium-Implications concerning the resolution of pulmonary edema

    PubMed Central

    Azizi, Fouad; Arredouani, Abdelilah; Mohammad, Ramzi M

    2015-01-01

    During airway inflammation, airway surface liquid volume (ASLV) expansion may result from the movement of plasma proteins and excess liquid into the airway lumen due to extravasation and elevation of subepithelial hydrostatic pressure. We previously demonstrated that elevation of submucosal hydrostatic pressure increases airway epithelium permeability resulting in ASLV expansion by 500 μL cm−2 h−1. Liquid reabsorption by healthy airway epithelium is regulated by active Na+ transport at a rate of 5 μL cm−2 h−1. Thus, during inflammation the airway epithelium may be submerged by a large volume of luminal liquid. Here, we have investigated the mechanism by which ASLV expansion alters active epithelial Na+ transport, and we have characterized the time course of the change. We used primary cultures of tracheal airway epithelium maintained under air interface (basal ASLV, depth is 7 ± 0.5 μm). To mimic airway flooding, ASLV was expanded to a depth of 5 mm. On switching from basal to expanded ASLV conditions, short-circuit current (Isc, a measure of total transepithelial active ion transport) declined by 90% with a half-time (t1/2) of 1 h. 24 h after the switch, there was no significant change in ATP concentration nor in the number of functional sodium pumps as revealed by [3H]-ouabain binding. However, amiloride-sensitive uptake of 22Na+ was reduced by 70% upon ASLV expansion. This process is reversible since after returning cells back to air interface, Isc recovered with a t1/2 of 5–10 h. These results may have important clinical implications concerning the development of Na+ channels activators and resolution of pulmonary edema. PMID:26333829

  4. An Anesthesiologist's Perspective on the History of Basic Airway Management: The "Preanesthetic" Era-1700 to 1846.

    PubMed

    Matioc, Adrian A

    2016-02-01

    Basic airway management modern history starts in the early 18th century in the context of resuscitation of the apparently dead. History saw the rise and fall of the mouth-to-mouth and then of the instrumental positive-pressure ventilation generated by bellows. Pulmonary ventilation had a secondary role to external and internal organ stimulation in resuscitation of the apparently dead. Airway access for the extraglottic technique was to the victim's nose. The bellows-to-nose technique was the "basic airway management technique" applicable by both medical and nonmedical personnel. Although the techniques had been described at the time, very few physicians practiced glottic (intubation) and subglottic (tracheotomy) techniques. Before the anesthetic era, positive-pressure ventilation was discredited and replaced by manual negative-pressure techniques. In the middle of the 19th century, physicians who would soon administer anesthetic gases were unfamiliar with the positive-pressure ventilation concept. PMID:26580835

  5. Relationship between Body Fat Distribution and Upper Airway Dynamic Function during Sleep in Adolescents

    PubMed Central

    Yuan, Haibo; Schwab, Richard J.; Kim, Christopher; He, Jiwei; Shults, Justine; Bradford, Ruth; Huang, Jingtao; Marcus, Carole L.

    2013-01-01

    Introduction: The obstructive sleep apnea syndrome (OSAS) is associated with increased visceral adipose tissue (VAT) in adults; however, few studies have evaluated VAT in relation to upper airway function in adolescents. We hypothesized that increased neck circumference (NC) and VAT would be associated with increased upper airway collapsibility. Methods: Adolescents (24 obese patients with OSAS, 22 obese control patients, and 29 lean control patients) underwent abdominal magnetic resonance imaging, and measurement of upper airway pressure-flow relationships in the activated and hypotonic upper airway states. Results: Patients with OSAS had a greater activated slope of the pressure-flow relationship (SPF) than control groups (P < 0.001), whereas hypotonic SPF was greater in both obese groups compared with lean control patients (P = 0.01). NC and VAT were greater in obese control patients and those with OSAS than in lean control patients (P < 0.001), but did not differ between obese patients with OSAS and obese control patients. In lean control patients and those with OSAS, increased NC was associated with increased activated SPF, whereas in obese control patients it was associated with decreased activated SPF (P = 0.03). In contrast, increased NC was associated with increased hypotonic SPF in all groups (P < 0.001). There was no significant effect of VAT on either activated or hypotonic SPF for any of the three groups. Conclusions: Increased neck circumference was associated with increased upper airway collapsibility in adolescents in the hypotonic but not activated state. These data suggest that obese adolescents without OSAS, despite a narrowed upper airway from adipose tissue, are protected from developing OSAS by upper airway neuromotor activation. Neither neck circumference nor visceral adipose tissue is useful in predicting upper airway collapsibility in obese adolescents. Citation: Yuan H; Schwab RJ; Kim C; He J; Shults J; Bradford R; Huang J; Marcus CL

  6. 21 CFR 868.5810 - Airway connector.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Airway connector. 868.5810 Section 868.5810 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5810 Airway connector. (a) Identification. An airway connector is a device intended to...

  7. Chronic effects of mechanical force on airways.

    PubMed

    Tschumperlin, Daniel J; Drazen, Jeffrey M

    2006-01-01

    Airways are embedded in the mechanically dynamic environment of the lung. In utero, this mechanical environment is defined largely by fluid secretion into the developing airway lumen. Clinical, whole lung, and cellular studies demonstrate pivotal roles for mechanical distention in airway morphogenesis and cellular behavior during lung development. In the adult lung, the mechanical environment is defined by a dynamic balance of surface, tissue, and muscle forces. Diseases of the airways modulate both the mechanical stresses to which the airways are exposed as well as the structure and mechanical behavior of the airways. For instance, in asthma, activation of airway smooth muscle abruptly changes the airway size and stress state within the airway wall; asthma also results in profound remodeling of the airway wall. Data now demonstrate that airway epithelial cells, smooth muscle cells, and fibroblasts respond to their mechanical environment. A prominent role has been identified for the epithelium in transducing mechanical stresses, and in both the fetal and mature airways, epithelial cells interact with mesenchymal cells to coordinate remodeling of tissue architecture in response to the mechanical environment. PMID:16460284

  8. Site of Fluid Secretion in Small Airways.

    PubMed

    Flores-Delgado, Guillermo; Lytle, Christian; Quinton, Paul M

    2016-03-01

    The secretion and management of readily transportable airway surface liquid (ASL) along the respiratory tract is crucial for the clearance of debris and pathogens from the lungs. In proximal large airways, submucosal glands (SMGs) can produce ASL. However, in distal small airways, SMGs are absent, although the lumens of these airways are, uniquely, highly plicated. Little is known about the production and maintenance of ASL in small airways, but using electrophysiology, we recently found that native porcine small airways simultaneously secrete and absorb. How these airways can concurrently transport ASL in opposite directions is puzzling. Using high expression of the Na-K-2Cl cotransport (NKCC) 1 protein (SLC12a2) as a phenotypic marker for fluid secretory cells, immunofluorescence microscopy of porcine small airways revealed two morphologically separated sets of luminal epithelial cells. NKCC1 was abundantly expressed by most cells in the contraluminal regions of the pleats but highly expressed very infrequently by cells in the luminal folds of the epithelial plications. In larger proximal airways, the acini of SMGs expressed NKCC1 prominently, but cells expressing NKCC1 in the surface epithelium were sparse. Our findings indicate that, in the small airway, cells in the pleats of the epithelium secrete ASL, whereas, in the larger proximal airways, SMGs mainly secrete ASL. We propose a mechanism in which the locations of secretory cells in the base of pleats and of absorptive cells in luminal folds physically help maintain a constant volume of ASL in small airways. PMID:26562629

  9. Mapping protein conformational heterogeneity under pressure with site-directed spin labeling and double electron-electron resonance.

    PubMed

    Lerch, Michael T; Yang, Zhongyu; Brooks, Evan K; Hubbell, Wayne L

    2014-04-01

    The dominance of a single native state for most proteins under ambient conditions belies the functional importance of higher-energy conformational states (excited states), which often are too sparsely populated to allow spectroscopic investigation. Application of high hydrostatic pressure increases the population of excited states for study, but structural characterization is not trivial because of the multiplicity of states in the ensemble and rapid (microsecond to millisecond) exchange between them. Site-directed spin labeling in combination with double electron-electron resonance (DEER) provides long-range (20-80 Å) distance distributions with angstrom-level resolution and thus is ideally suited to resolve conformational heterogeneity in an excited state populated under high pressure. DEER currently is performed at cryogenic temperatures. Therefore, a method was developed for rapidly freezing spin-labeled proteins under pressure to kinetically trap the high-pressure conformational ensemble for subsequent DEER data collection at atmospheric pressure. The methodology was evaluated using seven doubly-labeled mutants of myoglobin designed to monitor selected interhelical distances. For holomyoglobin, the distance distributions are narrow and relatively insensitive to pressure. In apomyoglobin, on the other hand, the distributions reveal a striking conformational heterogeneity involving specific helices in the pressure range of 0-3 kbar, where a molten globule state is formed. The data directly reveal the amplitude of helical fluctuations, information unique to the DEER method that complements previous rate determinations. Comparison of the distance distributions for pressure- and pH-populated molten globules shows them to be remarkably similar despite a lower helical content in the latter. PMID:24707053

  10. Mapping protein conformational heterogeneity under pressure with site-directed spin labeling and double electron–electron resonance

    PubMed Central

    Lerch, Michael T.; Yang, Zhongyu; Brooks, Evan K.; Hubbell, Wayne L.

    2014-01-01

    The dominance of a single native state for most proteins under ambient conditions belies the functional importance of higher-energy conformational states (excited states), which often are too sparsely populated to allow spectroscopic investigation. Application of high hydrostatic pressure increases the population of excited states for study, but structural characterization is not trivial because of the multiplicity of states in the ensemble and rapid (microsecond to millisecond) exchange between them. Site-directed spin labeling in combination with double electron–electron resonance (DEER) provides long-range (20–80 Å) distance distributions with angstrom-level resolution and thus is ideally suited to resolve conformational heterogeneity in an excited state populated under high pressure. DEER currently is performed at cryogenic temperatures. Therefore, a method was developed for rapidly freezing spin-labeled proteins under pressure to kinetically trap the high-pressure conformational ensemble for subsequent DEER data collection at atmospheric pressure. The methodology was evaluated using seven doubly-labeled mutants of myoglobin designed to monitor selected interhelical distances. For holomyoglobin, the distance distributions are narrow and relatively insensitive to pressure. In apomyoglobin, on the other hand, the distributions reveal a striking conformational heterogeneity involving specific helices in the pressure range of 0–3 kbar, where a molten globule state is formed. The data directly reveal the amplitude of helical fluctuations, information unique to the DEER method that complements previous rate determinations. Comparison of the distance distributions for pressure- and pH-populated molten globules shows them to be remarkably similar despite a lower helical content in the latter. PMID:24707053

  11. [Tapia's syndrome : Rare complication of securing airways].

    PubMed

    Brandt, L

    2015-02-01

    Nerve injuries are a rare complication of airway management. Two cases of Tapia's syndrome following orotracheal intubation are reported. Case 1: a 23-year-old male patient underwent an otorhinolaryngology (ENT) surgical procedure with orotracheal intubation. A left-sided Tapia's syndrome was verified 3 days later. Case 2: a 67-year-old patient developed a right-sided Tapia's syndrome following an arthroscopic intervention of the left shoulder in the beach-chair position. In both cases there was permanent damage of both nerves. On the basis of a comprehensive literature survey the reasons for an intubation-induced Tapia's syndrome are discussed. In order to avoid a glottis or immediate subglottic position it is recommended to check and to document the position of the cuff (depth of intubation) and the measured cuff pressure immediately after intubation. It also seems to be advisable to document an overstretched head position if required for the operation. PMID:25523320

  12. The ProSeal laryngeal mask airway.

    PubMed

    Brimacombe, Joseph; Keller, Christian

    2002-12-01

    The ProSeal LMA is a major advance over the Classic LMA because of the following reasons: it allows ventilation at much higher airway pressures; it protects the lungs from aspiration and the stomach from gastric insufflation; it facilitates passage of a gastric tube and monitoring devices into the esophagus; it can be inserted like the Classic or Intubating LMA; it has its own built-in bite block; malposition is detected more readily; and, through use of techniques such as gum elastic bougie-guided insertion, correct positioning is almost guaranteed. The ProSeal can be considered a replacement device for the Classic LMA, but the Flexible LMA is still preferable for most intraoral procedures, and the Intubating LMA is still preferable whenever intubation is required. Limitations are that it is slightly more difficult to insert and requires more careful thought to use optimally. PMID:12512267

  13. Computational Fluid Dynamic Analysis of the Posterior Airway Space After Maxillomandibular Advancement For Obstructive Sleep Apnea Syndrome

    PubMed Central

    Sittitavornwong, Somsak; Waite, Peter D.; Shih, Alan M.; Cheng, Gary C.; Koomullil, Roy; Ito, Yasushi; Cure, Joel K; Harding, Susan M.; Litaker, Mark

    2013-01-01

    Purpose Evaluate the soft tissue change of the upper airway after maxillomandibular advancement (MMA) by computational fluid dynamics (CFD). Materials and Methods Eight OSAS patients who required MMA were recruited into this study. All participants had pre- and post-operative computed tomography (CT) and underwent MMA by a single oral and maxillofacial surgeon. Upper airway CT data sets for these 8 participants were created with high-fidelity 3-D numerical models for computational fluid dynamics (CFD). The 3-D models were simulated and analyzed to study how changes in airway anatomy affects pressure effort required for normal breathing. Airway dimensions, skeletal changes, Apnea-Hypopnea Index (AHI), and pressure efforts of pre- and post-operative 3-D models were compared and correlations interpreted. Results After MMA, laminar and turbulent air flow was significantly decreased at every level of the airway. The cross-sectional areas at the soft palate and tongue base were significantly increased. Conclusions This study shows that MMA increases airway dimensions by the increasing the occipital base (Base) - pogonion (Pg) distance. An increase of the Base-Pg distance showed a significant correlation with an AHI improvement and a decreased pressure effort of the upper airway. Decreasing the pressure effort will decrease the breathing workload. This improves the condition of OSAS. PMID:23642544

  14. A pilot study to examine the effect of the Tulip oropharyngeal airway on ventilation immediately after mask ventilation following the induction of anaesthesia.

    PubMed

    Robinson, P N; Shaikh, A; Sabir, N M; Vaughan, D J A; Kynoch, M; Hasan, M

    2014-07-01

    The Tulip airway is an adult, disposable, single-sized oropharyngeal airway, that is connectable to an anaesthetic circuit. After a standardised induction of anaesthesia in 75 patients, the ease of insertion, intracuff pressure and intracuff volume were measured, as were the end-tidal carbon dioxide levels, airway pressures and tidal volumes over three breaths. Successful first-time insertion was achieved in 72 patients (96%, CI 88.8-99.2%) and after two attempts in 74 patients (99%, CI 92.8-100%). There was outright failure only in one patient. In 60 patients (80%, CI 72.2-90.4%), the Tulip airway provided a patent airway without additional manoeuvres, but in 14 patients, jaw thrust or head extension was necessary for airway patency. The main need for these adjuncts appeared to be an initial under-inflation of the cuff. These promising results are consistent with recent manikin studies using this device. PMID:24773326

  15. Plasma exudation in the airways: mechanisms and function.

    PubMed

    Persson, C G

    1991-11-01

    Inflammatory challenges of tracheobronchial and nasal mucosa produce prompt extravasation or exudation of plasma from the well developed microcirculation just beneath the epithelial base. Plasma exudation is not an exaggeration of the normal capilliary exchange of fluid and solutes but a specific inflammatory response of post-capilliary venules. The exuded plasma may not produce oedema. By a rapid, undirectional, unfiltered and yet non-injurious process, plasma exudates cross the mucosal lining to appear on the airway surface at the site of challenge. In vitro data suggests the possibility that a slightly increased hydrostatic pressure moves the acellular exudate through valve-like openings between epithelial cells. By the venular-mucosal exudation mechanism all the potent protein systems of circulating plasma will operate in respiratory defence on the surface of an intact mucosa. A further inference is that exudative indices obtained from the airway surface quantitatively reflect the intensity and time course of mucosal/submucosal inflammatory processes. Irrespective of which particular cellular mechanism happens to fuel the inflammation. Mucosal exudation of plasma characteristically occurs in health and disease also when there is no airway oedema, no epithelial disruption, and no increased absorbtion ability. However, exuded plasma and its derived peptide mediators potentially contribute to several pathophysical and pathophysiological characteristics of inflammatory airway diseases. PMID:1804675

  16. [Airway equipment and its maintenance for a non difficult adult airway management (endotracheal intubation and its alternative: face mask, laryngeal mask airway, laryngeal tube)].

    PubMed

    Francon, D; Estèbe, J P; Ecoffey, C

    2003-08-01

    The airway equipment for a non difficult adult airway management are described: endotracheal tubes with a specific discussion on how to inflate the balloon, laryngoscopes and blades, stylets and intubation guides, oral airways, face masks, laryngeal mask airways and laryngeal tubes. Cleaning and disinfections with the maintenance are also discussed for each type of airway management. PMID:12943860

  17. Jaw thrust can deteriorate upper airway patency.

    PubMed

    von Ungern-Sternberg, B S; Erb, T O; Frei, F J

    2005-04-01

    Upper airway obstruction is a frequent problem in spontaneously breathing children undergoing anesthesia or sedation procedures. Failure to maintain a patent airway can rapidly result in severe hypoxemia, bradycardia, or asystole, as the oxygen demand of children is high and oxygen reserve is low. We present two children with cervical masses in whom upper airway obstruction exaggerated while the jaw thrust maneuver was applied during induction of anesthesia. This deterioration in airway patency was probably caused by medial displacement of the lateral tumorous tissues which narrowed the pharyngeal airway. PMID:15777312

  18. Excessive Dynamic Airway Collapse: An Unexpected Contributor to Respiratory Failure in a Surgical Patient.

    PubMed

    Lyaker, Michael R; Davila, Victor R; Papadimos, Thomas J

    2015-01-01

    Central airway collapse plays a significant, underrecognized role in respiratory failure after extubation of critically ill patients. Historically, airway collapse has been attributed to tracheomalacia (TM), softening of the cartilage in the trachea and other large airways. More recently, excessive dynamic airway collapse (EDAC) has been described as a distinct process unrelated to a loss of cartilaginous airway support. EDAC is caused by the posterior wall of the trachea bulging forward and causing airway obstruction during exhalation. This process is exaggerated when intrathoracic pressure is increased and results in a clinical picture of coughing, difficulty clearing secretions, dyspnea, and stridor. The increased use of computerized tomography and fiberoptic bronchoscopy has identified varying degrees of EDAC and TM in both symptomatic and asymptomatic individuals. This has led to renewed consideration of airway collapse and the different processes that contribute to it. Here we describe a 43-year-old morbidly obese patient who failed repeated attempts at extubation after elective hysterectomy. We will discuss the processes of EDAC and TM, describe how this condition contributed to this patient's respiratory failure, and review diagnosis and management options. PMID:26167306

  19. Excessive Dynamic Airway Collapse: An Unexpected Contributor to Respiratory Failure in a Surgical Patient

    PubMed Central

    Lyaker, Michael R.; Davila, Victor R.; Papadimos, Thomas J.

    2015-01-01

    Central airway collapse plays a significant, underrecognized role in respiratory failure after extubation of critically ill patients. Historically, airway collapse has been attributed to tracheomalacia (TM), softening of the cartilage in the trachea and other large airways. More recently, excessive dynamic airway collapse (EDAC) has been described as a distinct process unrelated to a loss of cartilaginous airway support. EDAC is caused by the posterior wall of the trachea bulging forward and causing airway obstruction during exhalation. This process is exaggerated when intrathoracic pressure is increased and results in a clinical picture of coughing, difficulty clearing secretions, dyspnea, and stridor. The increased use of computerized tomography and fiberoptic bronchoscopy has identified varying degrees of EDAC and TM in both symptomatic and asymptomatic individuals. This has led to renewed consideration of airway collapse and the different processes that contribute to it. Here we describe a 43-year-old morbidly obese patient who failed repeated attempts at extubation after elective hysterectomy. We will discuss the processes of EDAC and TM, describe how this condition contributed to this patient's respiratory failure, and review diagnosis and management options. PMID:26167306

  20. Sensory neuropeptides and airway function.

    PubMed

    Solway, J; Leff, A R

    1991-12-01

    Sensory nerves synthesize tachykinins and calcitonin-gene related peptide and package these neuropeptides together in synaptic vesicles. Stimulation of these C-fibers by a range of chemical and physical factors results in afferent neuronal conduction that elicits central parasympathetic reflexes and in antidromic conduction that results in local release of neuropeptides through the axon reflex. In the airways, sensory neuropeptides act on bronchial smooth muscle, the mucosal vasculature, and submucosal glands to promote airflow obstruction, hyperemia, microvascular hyperpermeability, and mucus hypersecretion. In addition, tachykinins potentiate cholinergic neurotransmission. Proinflammatory effects of these peptides also promote the recruitment, adherence, and activation of granulocytes that may further exacerbate neurogenic inflammation (i.e., neuropeptide-induced plasma extravasation and vasodilation). Enzymatic degradation limits the physiological effects of tachykinins but may be impaired by respiratory infection or other factors. Given their sensitivity to noxious compounds and physical stimuli and their potent effects on airway function, it is possible that neuropeptide-containing sensory nerves play an important role in mediating airway responses in human disease. Supporting this view are the striking phenomenological similarities between hyperpnea-induced bronchoconstriction (HIB) in guinea pigs and HIB in patients with exercise-induced asthma. Endogenous tachykinins released from airway sensory nerves mediate HIB in guinea pigs and also cause hyperpnea-induced bronchovascular hyperpermeability in these animals. On the basis of these observations, it is reasonable to speculate that sensory neuropeptides participate in the pathogenesis of hyperpnea-induced airflow obstruction in human asthmatic subjects as well. PMID:1663932

  1. Kinematic mapping reveals different spatial distributions of center of pressure high-speed regions under somatosensory loss.

    PubMed

    Portela, Fellipe M; Ferreira, Arthur S

    2014-01-01

    The spatial distribution of center-of-pressure speed during postural tasks and its changes due to somatosensory constraint (temporary ischemic hypoxia on ankle/feet) were investigated in young, healthy subjects (n = 13). A single high-speed region in the central region of the statokinesigram was observed during postural tasks with full sensory information. A significant increase in the quantity of high-speed regions was observed during ischemia and somatosensory constraint, whereas a significant increase in the quantity of high-speed regions localized more distant to the center of center-of-pressure area occurred under somatosensory constraints, suggesting a redirection of center-of-pressure trajectory to adjust the position of the center of mass with respect to the egocentric reference of balance. PMID:24945569

  2. A Direct Method for Mapping the Center of Pressure Measured by an Insole Pressure Sensor System to the Shoe's Local Coordinate System.

    PubMed

    Weaver, Brian T; Braman, Jerrod E; Haut, Roger C

    2016-06-01

    A direct method to express the center of pressure (CoP) measured by an insole pressure sensor system (IPSS) into a known coordinate system measured by motion tracking equipment is presented. A custom probe was constructed with reflective markers to allow its tip to be precisely tracked with motion tracking equipment. This probe was utilized to activate individual sensors on an IPSS that was placed in a shoe fitted with reflective markers used to establish a local shoe coordinate system. When pressed onto the IPSS the location of the probe's tip was coincident with the CoP measured by the IPSS (IPSS-CoP). Two separate pushes (i.e., data points) were used to develop vectors in each respective coordinate system. Simple vector mathematics determined the rotational and translational components of the transformation matrix needed to express the IPSS-CoP into the local shoe coordinate system. Validation was performed by comparing IPSS-CoP with an embedded force plate measured CoP (FP-CoP) from data gathered during kinematic trials. Six male subjects stood on an embedded FP and performed anterior/posterior (AP) sway, internal rotation, and external rotation of the body relative to a firmly planted foot. The IPSS-CoP was highly correlated with the FP-CoP for all motions, root mean square errors (RMSRRs) were comparable to other research, and there were no statistical differences between the displacement of the IPSS-CoP and FP-CoP for both the AP and medial/lateral (ML) axes, respectively. The results demonstrated that this methodology could be utilized to determine the transformation variables need to express IPSS-CoP into a known coordinate system measured by motion tracking equipment and that these variables can be determined outside the laboratory anywhere motion tracking equipment is available. PMID:27109294

  3. Systems-level airway models of bronchoconstriction.

    PubMed

    Donovan, Graham M

    2016-09-01

    Understanding lung and airway behavior presents a number of challenges, both experimental and theoretical, but the potential rewards are great in terms of both potential treatments for disease and interesting biophysical phenomena. This presents an opportunity for modeling to contribute to greater understanding, and here, we focus on modeling efforts that work toward understanding the behavior of airways in vivo, with an emphasis on asthma. We look particularly at those models that address not just isolated airways but many of the important ways in which airways are coupled both with each other and with other structures. This includes both interesting phenomena involving the airways and the layer of airway smooth muscle that surrounds them, and also the emergence of spatial ventilation patterns via dynamic airway interaction. WIREs Syst Biol Med 2016, 8:459-467. doi: 10.1002/wsbm.1349 For further resources related to this article, please visit the WIREs website. PMID:27348217

  4. The Importance of Airway Management in Trauma

    PubMed Central

    Jacobs, Lenworth M.

    1988-01-01

    The airway is the most important priority in the management of the severely injured patient. It is essential to open and clear the airway to allow free access of air to the distal endobronchial tree. Manual methods of opening the airway are described. Numerous methods for establishing definitive control of the airway as well as the associated devices currently available to maintain control are described. Once the airway is maintained, it is important to ensure adequate oxygenation and ventilation through the airway. Modern portable devices that monitor the carbon dioxide in the expired air at the end of each breath are currently available. These devices allow the physician to verify the position of the tube in the airway as well as to continuously monitor the efficacy of ventilation. PMID:3073226

  5. Sarcoidosis of the upper and lower airways.

    PubMed

    Morgenthau, Adam S; Teirstein, Alvin S

    2011-12-01

    Sarcoidosis is a systemic granulomatous disease of undetermined etiology characterized by a variable clinical presentation and disease course. Although clinical granulomatous inflammation may occur within any organ system, more than 90% of sarcoidosis patients have lung disease. Sarcoidosis is considered an interstitial lung disease that is frequently characterized by restrictive physiologic dysfunction on pulmonary function tests. However, sarcoidosis also involves the airways (large and small), causing obstructive airways disease. It is one of a few interstitial lung diseases that affects the entire length of the respiratory tract - from the nose to the terminal bronchioles - and causes a broad spectrum of airways dysfunction. This article examines airway dysfunction in sarcoidosis. The anatomical structure of the airways is the organizational framework for our discussion. We discuss sarcoidosis involving the nose, sinuses, nasal passages, larynx, trachea, bronchi and small airways. Common complications of airways disease, such as, atelectasis, fibrosis, bullous leions, bronchiectasis, cavitary lesions and mycetomas, are also reviewed. PMID:22082167

  6. Liquid plug propagation in flexible microchannels: A small airway model

    NASA Astrophysics Data System (ADS)

    Zheng, Y.; Fujioka, H.; Bian, S.; Torisawa, Y.; Huh, D.; Takayama, S.; Grotberg, J. B.

    2009-07-01

    In the present study, we investigate the effect of wall flexibility on the plug propagation and the resulting wall stresses in small airway models with experimental measurements and numerical simulations. Experimentally, a flexible microchannel was fabricated to mimic the flexible small airways using soft lithography. Liquid plugs were generated and propagated through the microchannels. The local wall deformation is observed instantaneously during plug propagation with the maximum increasing with plug speed. The pressure drop across the plug is measured and observed to increase with plug speed, and is slightly smaller in a flexible channel compared to that in a rigid channel. A computational model is then presented to model the steady plug propagation through a flexible channel corresponding to the middle plane in the experimental device. The results show qualitative agreements with experiments on wall shapes and pressure drops and the discrepancies bring up interesting questions on current field of modeling. The flexible wall deforms inward near the plug core region, the deformation and pressure drop across the plug increase with the plug speed. The wall deformation and resulting stresses vary with different longitudinal tensions, i.e., for large wall longitudinal tension, the wall deforms slightly, which causes decreased fluid stress and stress gradients on the flexible wall comparing to that on rigid walls; however, the wall stress gradients are found to be much larger on highly deformable walls with small longitudinal tensions. Therefore, in diseases such as emphysema, with more deformable airways, there is a high possibility of induced injuries on lining cells along the airways because of larger wall stresses and stress gradients.

  7. Hyperpolarized 3He magnetic resonance imaging ventilation defects in asthma: relationship to airway mechanics.

    PubMed

    Leary, Del; Svenningsen, Sarah; Guo, Fumin; Bhatawadekar, Swati; Parraga, Grace; Maksym, Geoffrey N

    2016-04-01

    In patients with asthma, magnetic resonance imaging (MRI) provides direct measurements of regional ventilation heterogeneity, the etiology of which is not well-understood, nor is the relationship of ventilation abnormalities with lung mechanics. In addition, respiratory resistance and reactance are often abnormal in asthmatics and the frequency dependence of respiratory resistance is thought to reflect ventilation heterogeneity. We acquiredMRIventilation defect maps, forced expiratory volume in one-second (FEV1), and airways resistance (Raw) measurements, and used a computational airway model to explore the relationship of ventilation defect percent (VDP) with simulated measurements of respiratory system resistance (Rrs) and reactance (Xrs).MRIventilation defect maps were experimentally acquired in 25 asthmatics before, during, and after methacholine challenge and these were nonrigidly coregistered to the airway tree model. Using the model coregistered to ventilation defect maps, we narrowed proximal (9th) and distal (14th) generation airways that were spatially related to theMRIventilation defects. The relationships forVDPwith Raw measured using plethysmography (r = 0.79), and model predictions of Rrs>14(r = 0.91,P < 0.0001) and Rrs>9(r = 0.88,P < 0.0001) were significantly stronger (P = 0.005;P = 0.03, respectively) than withFEV1(r = -0.68,P = 0.0001). The slopes for the relationship ofVDPwith simulated lung mechanics measurements were different (P < 0.0001); among these, the slope for theVDP-Xrs0.2relationship was largest, suggesting thatVDPwas dominated by peripheral airway heterogeneity in these patients. In conclusion, as a first step toward understanding potential links between lung mechanics and ventilation defects, impedance predictions were made using a computational airway tree model with simulated constriction of airways related to ventilation defects measured in mild-moderate asthmatics. PMID:27053294

  8. Acute exposure to hair bleach causes airway hyperresponsiveness in a rabbit model.

    PubMed

    Mensing, T; Marek, W; Raulf-Heimsoth, M; Baur, X

    1998-12-01

    Ammonium persulphate (APS) and hydrogen peroxide (H2O2) are used as oxidants in many industrial processes and are the main constituents of standard hair bleaching products. In a previous study, it was demonstrated that aerosols of APS induce alterations in airway responsiveness. The present study examined whether exposure for 4 h to a hair bleach composition (containing APS, potassium persulphate and H2O2) or H2O2 could induce airway hyperresponsiveness and/or an obstructive ventilation pattern in a rabbit model. Exposure to the aerosols altered neither baseline airway resistance, dynamic elastance, slope of inspiratory pressure generation nor arterial blood pressure and blood gas measurements. Similarly to APS, hair bleach aerosols containing > or =10.9 mg x m(-3) persulphate (ammonium and potassium salt) in air and > or =1.36 mg x m(-3) H2O2 in air caused airway hyperresponsiveness to acetylcholine after 4 h of exposure. Aerosolized H2O2 (> or =37 mg x m(-3) in air) did not influence airway responsiveness to acetylcholine. The results demonstrate that hair bleaching products containing persulphates dissolved in H2O2 cause airway hyperresponsiveness to acetylcholine in rabbits. PMID:9877493

  9. Acute unilateral submandibular gland swelling associated with the laryngeal mask airway.

    PubMed

    Suhitharan, Thangavelautham; Seevanayagam, Sathyendran; Parker, Francis Christopher; Teoh, Wendy Hui Ling

    2013-12-01

    We describe a rare complication of acute unilateral submandibular gland swelling following the use of laryngeal mask airway (LMA) in two patients with otherwise uneventful perioperative airway management. This is likely to be a consequence of the pressure exerted by the airway cuff on the tissues within the submandibular triangle. As this complication is rarely reported, its true incidence may in fact be higher, suggesting a need for greater attention on LMA cuff pressures and degree of cuff inflation. We discuss the presenting clinical features, pathophysiology and utilisation of ultrasonographic confirmation of sialadenopathy, and review the current anaesthetic literature to raise awareness of this unusual and under-reported complication of LMA. This complication can be mitigated by incorporating routine manometric checks and limiting intracuff pressures to < 60 cmH2O, potentially avoiding LMA insertions in patients with sialolithiasis and avoiding the use of nitrous oxide. PMID:24356762

  10. Origins of and implementation concepts for upper airway stimulation therapy for obstructive sleep apnea.

    PubMed

    Strohl M D, Kingman P; Baskin M D, Jonathan; Lance M D, Colleen; Ponsky M D, Diana; Weidenbecher M D, Mark; Strohl B A, Madeleine; Yamauchi M D, Motoo

    2016-07-01

    Upper airway stimulation, specifically hypoglossal (CN XII) nerve stimulation, is a new, alternative therapy for patients with obstructive sleep apnea hypopnea syndrome who cannot tolerate positive airway pressure, the first-line therapy for symptomatic patients. Stimulation therapy addresses the cause of inadequate upper airway muscle activation for nasopharyngeal and oropharyngeal airway collapse during sleep. The purpose of this report is to outline the development of this first-in-class therapy and its clinical implementation. Another practical theme is assessment of the features for considering a surgically implanted device and the insight as to how both clinical and endoscopic criteria increase the likelihood of safe and durable outcomes for an implant and how to more generally plan for management of CPAP-intolerant patients. A third theme is the team building required among sleep medicine and surgical specialties in the provision of individualized neurostimulation therapy. PMID:27424823

  11. Application of the laryngeal mask airway for anesthesia in three chimpanzees and one gibbon.

    PubMed

    Johnson, Jacob A; Atkins, Adrienne L; Heard, Darryl J

    2010-09-01

    Three pediatric chimpanzees and one pediatric gibbon were anesthetized for routine physical examination. Anesthesia was maintained with inhalant delivered via a laryngeal mask airway (LMA). The LMA was easy to insert, provided adequate control of the airway for ventilation, and caused no tracheal stimulation. No complications were observed. As compared with a face mask, the LMA has the advantage of a more secure airway; the ability to effectively ventilate the patient; less dead space, which leads to lower rebreathing of carbon dioxide; and less exposure of personnel to waste gases. As compared with an endotracheal tube, the LMA causes less airway trauma, is easier to place, and is less stimulating to the patient. The LMA should be considered for use in fasted non-human primates presented for procedures lasting less than 60 min where high peak inspiratory pressures are not needed. PMID:20945657

  12. Acoustically detectable cellular-level lung injury induced by fluid mechanical stresses in microfluidic airway systems.

    PubMed

    Huh, Dongeun; Fujioka, Hideki; Tung, Yi-Chung; Futai, Nobuyuki; Paine, Robert; Grotberg, James B; Takayama, Shuichi

    2007-11-27

    We describe a microfabricated airway system integrated with computerized air-liquid two-phase microfluidics that enables on-chip engineering of human airway epithelia and precise reproduction of physiologic or pathologic liquid plug flows found in the respiratory system. Using this device, we demonstrate cellular-level lung injury under flow conditions that cause symptoms characteristic of a wide range of pulmonary diseases. Specifically, propagation and rupture of liquid plugs that simulate surfactant-deficient reopening of closed airways lead to significant injury of small airway epithelial cells by generating deleterious fluid mechanical stresses. We also show that the explosive pressure waves produced by plug rupture enable detection of the mechanical cellular injury as crackling sounds. PMID:18006663

  13. Comparison of laryngeal mask airway use with endotracheal intubation during anesthesia of western lowland gorillas (Gorilla gorilla gorilla).

    PubMed

    Cerveny, Shannon N; D'Agostino, Jennifer J; Davis, Michelle R; Payton, Mark E

    2012-12-01

    The laryngeal mask airway is an alternative to endotracheal intubation that achieves control of the airway by creating a seal around the larynx with an inflatable cuff. This study compared use of the laryngeal mask airway with endotracheal intubation in anesthetized western lowland gorillas (Gorilla gorilla gorilla). Eight adult gorillas were immobilized for routine and diagnostic purposes for a total of nine anesthetic events. During each anesthetic event, gorillas were either intubated (n = 4; group A) or fitted with a laryngeal mask airway (n= 5; group B). Time required to place each airway device, physiologic parameters, and arterial blood gas were measured and compared between the two groups. There were no significant differences between the two groups for time required to place airway device, heart rate, hemoglobin oxygen saturation, end-tidal carbon dioxide, arterial partial pressure of carbon dioxide, or arterial pH between the two groups. Mean arterial partial pressure of oxygen was significantly greater in group B, 15 (group A: 94 +/- 44 mm Hg; group B: 408 +/- 36 mm Hg; P= 0.0025) and 45 (group A: 104 +/- 21 mm Hg; group B: 407 +/- 77 mm Hg; P = 0.0026) min after airway device placement. Mean respiratory rate was significantly greater in group A at multiple time points. Mean arterial pressure (group A: 129 +/- 16 mm Hg; group B: 60 +/- 8 mm Hg) and diastolic blood pressure (group A: 115 +/- 21 mm Hg; group B: 36 +/- 10 mm Hg) were significantly greater in group A at the time of airway device placement. The laryngeal mask airway maintained oxygenation and ventilation effectively in all gorillas and is a useful alternative to endotracheal intubation in western lowland gorillas. PMID:23272342

  14. Validation of computational fluid dynamics methodology used for human upper airway flow simulations.

    PubMed

    Mylavarapu, Goutham; Murugappan, Shanmugam; Mihaescu, Mihai; Kalra, Maninder; Khosla, Sid; Gutmark, Ephraim

    2009-07-22

    An anatomically accurate human upper airway model was constructed from multiple magnetic resonance imaging axial scans. This model was used to conduct detailed Computational Fluid Dynamics (CFD) simulations during expiration, to investigate the fluid flow in the airway regions where obstruction could occur. An identical physical model of the same airway was built using stereo lithography. Pressure and velocity measurements were conducted in the physical model. Both simulations and experiments were performed at a peak expiratory flow rate of 200 L/min. Several different numerical approaches within the FLUENT commercial software framework were used in the simulations; unsteady Large Eddy Simulation (LES), steady Reynolds-Averaged Navier-Stokes (RANS) with two-equation turbulence models (i.e. k-epsilon, standard k-omega, and k-omega Shear Stress Transport (SST)) and with one-equation Spalart-Allmaras model. The CFD predictions of the average wall static pressures at different locations along the airway wall were favorably compared with the experimental data. Among all the approaches, standard k-omega turbulence model resulted in the best agreement with the static pressure measurements, with an average error of approximately 20% over all ports. The highest positive pressures were observed in the retroglossal regions below the epiglottis, while the lowest negative pressures were recorded in the retropalatal region. The latter is a result of the airflow acceleration in the narrow retropalatal region. The largest pressure drop was observed at the tip of the soft palate. This location has the smallest cross section of the airway. The good agreement between the computations and the experimental results suggest that CFD simulations can be used to accurately compute aerodynamic flow characteristics of the upper airway. PMID:19501360

  15. 3D Mapping of plasma effective areas via detection of cancer cell damage induced by atmospheric pressure plasma jets

    NASA Astrophysics Data System (ADS)

    Han, Xu; Liu, Yueing; Stack, M. Sharon; Ptasinska, Sylwia

    2014-12-01

    In the present study, a nitrogen atmospheric pressure plasma jet (APPJ) was used for irradiation of oral cancer cells. Since cancer cells are very susceptible to plasma treatment, they can be used as a tool for detection of APPJ-effective areas, which extended much further than the visible part of the APPJ. An immunofluorescence assay was used for DNA damage identification, visualization and quantification. Thus, the effective damage area and damage level were determined and plotted as 3D images.

  16. Dynamics of heat, water, and soluble gas exchange in the human airways: 1. A model study.

    PubMed

    Tsu, M E; Babb, A L; Ralph, D D; Hlastala, M P

    1988-01-01

    In order to provide a means for analysis of heat, water, and soluble gas exchange with the airways during tidal ventilation, a one dimensional theoretical model describing heat and water exchange in the respiratory airways has been extended to include soluble gas exchange with the airway mucosa and water exchange with the mucous layer lining the airways. Not only do heat, water, and gas exchange occur simultaneously, but they also interact. Heating and cooling of the airway surface and mucous lining affects both evaporative water and soluble gas exchange. Water evaporation provides a major source of heat exchange. The model-predicted mean airway temperature profiles agree well with literature data for both oral and nasal breathing validating that part of the model. With model parameters giving the best fit to experimental data, the model shows: (a) substantial heat recovery in the upper airways, (b) minimal respiratory heat and water loss, and (c) low average mucous temperatures and maximal increases in mucous thickness. For resting breathing of room air, heat and water conservation appear to be more important than conditioning efficiency. End-tidal expired partial pressures of very soluble gases eliminated by the lungs are predicted to be lower than the alveolar partial pressures due to the absorption of the expired gases by the airway mucosa. The model may be usable for design of experiments to examine mechanisms associated with the local hydration and dehydration dynamics of the mucosal surface, control of bronchial perfusion, triggering of asthma, mucociliary clearance and deposition of inhaled pollutant gases. PMID:3228218

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

    PubMed

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

    2014-08-01

    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 add value to existing public health knowledge by: 1) proposing a common framework of care pathways for chronic respiratory diseases, which will facilitate comparability and trans-national initiatives; 2) informing cost-effective policy development, strengthening in particular those on smoking and environmental exposure; 3) aiding risk stratification in chronic disease patients, using a common strategy; 4) having a significant impact on the health of citizens in the short term (reduction of morbidity, improvement of education in children and of work in adults) and in the long-term (healthy ageing); 5) proposing a common simulation tool to assist physicians; and 6) ultimately reducing the healthcare burden (emergency visits, avoidable hospitalisations, disability and costs) while improving quality of life. In the longer term, the incidence of disease may be reduced by innovative prevention strategies. AIRWAYSICPs was initiated by Area 5 of the Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing. All stakeholders are involved (health and social care, patients, and policy makers). PMID:24925919

  18. Interaction between haemopoietic regulation and airway inflammation.

    PubMed

    O'Byrne, P M; Gauvreau, G M; Wood, L J

    1999-06-01

    Asthma is characterized by reversible airway narrowing, by airway hyperresponsiveness, and by airway inflammation. Inhaled allergens are the most important of the stimuli known to cause asthma. Methods for studying inhaled allergen in the laboratory have been well standardized and extensively used for the investigation of the pathophysiology and the pharmacological modulation of allergen-induced airway responses. Allergen inhalation by a sensitized subject results in an early asthmatic response, and, in the majority of subjects, a late asthmatic response and airway hyperresponsiveness. The late response and airway hyperresponsiveness are associated with increases in airway eosinophils and metachromatic cells. Allergen-induced airway inflammation in dogs (predominantly neutrophilic) is associated with increased granulocyte-macrophage progenitors in bone marrow, which is dependent on the effects of a circulating serum factor stimulating the bone marrow. The newly formed cells traffic to the airways. These increases in granulocyte-macrophage progenitors are blocked by inhaled corticosteroids. In human subjects, allergen-induced eosinophilic inflammation is associated with increases in Eo/B progenitors, mediated through up-regulation if the IL-5 receptor on progenitors and increases responsiveness to IL-5. Inhaled corticosteroids also attenuate all allergen-induced physiological responses and airway inflammation, an effect possibly mediated, in part, through inhibition of eosinophil and basophil maturation or release from the bone marrow. PMID:10421819

  19. Paediatric airway management: What is new?

    PubMed Central

    Ramesh, S; Jayanthi, R; Archana, SR

    2012-01-01

    Airway management plays a pivotal role in Paediatric Anaesthesia. Over the last two decades many improvements in this area have helped us to overcome this final frontier. From an era where intubation with a conventional laryngoscope or blind nasal intubation was the only tool for airway management, we have come a long way. Today supraglottic airway devices have pride of place in the Operating Room and are becoming important airway devices used in routine procedures. Direct and indirect fibreoptic laryngoscopes and transtracheal devices help us overcome difficult and previously impossible airway situations. These developments mean that we need to update our knowledge on these devices. Also much of our basic understanding of the physiology and anatomy of the paediatric airway has changed. This article attempts to shed light on some of the most important advances/opinions in paediatric airway management like, cuffed endotracheal tubes, supraglottic airway devices, video laryngoscopes, rapid sequence intubation, the newly proposed algorithm for difficult airway management and the role of Ex Utero Intrapartum Treatment (EXIT) procedure in the management of the neonatal airway. PMID:23293383

  20. The Difficult Paediatric Airway: Two Cases of large Cystic Hygroma

    PubMed Central

    Agarwal, Aditya; Mehrotra, Shikha

    2016-01-01

    This is a report of a two cases of difficult intubation experienced in paediatric surgical cases. Both the infants, aged one and three-month-old respectively, had very large cystic hygroma of the neck area. Prior hematological and radiological investigations (USG and CT scan of the swelling) and preanaesthesia check up was done and cases were posted for surgical excision. Case I had difficult airway due to pressure of the tumour/cystic hygroma over the airway and posed difficulty for intubation, but was managed well. Case II had respiratory distress during preoperative period. She had been postponed for surgical excision of the cystic hygroma of neck twice due to the difficulties experienced during intubation. Needle aspiration of hygroma fluid helped to reduce the respiratory distress, and the size of the tumour as well, which further helped in the smooth intubation after a week. The postoperative period was uneventful in both the infants. PMID:26894158

  1. Airway anastomosis for lung transplantation

    PubMed Central

    Diso, Daniele; Rendina, Erino Angelo; Venuta, Federico

    2016-01-01

    Lung transplantation (LT) is the only viable option for a selected group of patients with end stage pulmonary diseases. During the recent years satisfactory results in terms of long-term survival and quality of life have been achieved with improvements in surgical technique, immunosuppression and perioperative management. Since the beginning, the airway anastomosis has been considered crucial and significant efforts have been made to understand the healing process. A number of experimental studies allowed improving the surgical technique by modifying the technique of suturing, the anastomotic protection and type and dose of immunosuppression, reducing the risk of airway complications. Furthermore, a huge progress has been made in the management of such complications. Early diagnosis of bronchial complications and their prompt and correct management are crucial to achieve long-term survival. PMID:26981271

  2. Three-dimensional true color topographical analysis of the pulmonary airways

    NASA Astrophysics Data System (ADS)

    Suter, Melissa J.; Reinhardt, Joseph M.; Sonka, Milan; Higgins, William E.; Hoffman, Eric A.; McLennan, Geoffrey

    2004-04-01

    The development of pulmonary airway disease is characterized by mucosal color and topographical changes. Traditionally subjective visual interpretation of a bronchoscope procedure defines the identification of pulmonary airway disease however we have developed an optical imaging system used in conjunction with CT images to potentially quantify and classify these subtle variations. This paper presents a method for the construction of true color 3D images of the pulmonary airways from both optical and CT image data. Shape from Shading methods in the past decade have continually strived to achieve this goal by extracting 3D information from captured 2D images however these attempts have been severely limited in their application to bronchoscope images. Conversely the utilization of CT scans provides a sound tool for determining the gross structural anatomy of the airways however the accuracy of the rendered topographical surface maps is limited due to the resolution of the CT image data. Through integration of both the optical and CT imaging modalities we hope to create high resolution true color 3D images providing the necessary color and texture information to aid in future detection and classification of possible pulmonary airway disease. Preliminary combined color and texture results associated with various pulmonary airway diseases are presented highlighting the usefulness of this analysis technique.

  3. Partial airway obstruction following manufacturing defect in laryngeal mask airway (Laryngeal Mask Silken™).

    PubMed

    Jangra, Kiran; Malhotra, Surender Kumar; Saini, Vikas

    2014-10-01

    Laryngeal mask (LM) airway is commonly used for securing airway in day-care surgeries. Various problems have been described while using LM airway. Out of those, mechanical obstruction causing airway compromise is most common. Here, we describe a case report of 4-year-old child who had partial upper airway obstruction due to LM manufacturer's defect. There was a silicon band in upper one-third of shaft of LM airway. This band was made up of the same material as that of LM airway so it was not identifiable on external inspection of transparent shaft. We suggest that such as non-transparent laryngeal mask, a transparent LM airway should also be inspected looking inside the lumen with naked eyes or by using a probe to rule out any manufacturing defect before its insertion. PMID:25422617

  4. Air-Q laryngeal airway for rescue and tracheal intubation.

    PubMed

    Ads, Ayman; Auerbach, Frederic; Ryan, Kelly; El-Ganzouri, Abdel R

    2016-08-01

    to the surgical intensive care unit (SICU). During day 2 of his SICU stay, he accidentally self-extubated and Spo2 dropped to 20% prompting a code blue call. A size 4.5 Air-Q LA was successfully placed by the anesthesia resident on call and Spo2 rose to 100%. The airway was then secured after suction of bloody secretions and visualization of edematous vocal cords with a fiberoptic bronchoscope and proper placement of an endotracheal tube of 7.5-mm internal diameter, confirmed by capnography. During the short period of hypoxemia, the patient's blood pressure, heart rate, and electrocardiogram had remained stable. On the sixth day of SICU admission, he underwent surgical tracheostomy and laser excision of a stenotic tracheal lesion, returned to the SICU, was weaned off mechanical ventilation, and discharged 2 weeks later to a rehabilitation center with stable ventilatory capabilities. This case demonstrates successful use of the Air-Q LA in the emergency loss of airway scenario as a ventilatory device and as a conduit for endotracheal intubation when fiberoptic bronchoscopy alone may be difficult and hazardous. This case suggests the need for further evaluation of the impact of the Air-Q LA on outcomes when used as a rescue device and conduit for tracheal intubation in patient with disease activity. PMID:27290957

  5. Mechanisms of surface-tension-induced epithelial cell damage in a model of pulmonary airway reopening.

    PubMed

    Bilek, Anastacia M; Dee, Kay C; Gaver, Donald P

    2003-02-01

    Airway collapse and reopening due to mechanical ventilation exerts mechanical stress on airway walls and injures surfactant-compromised lungs. The reopening of a collapsed airway was modeled experimentally and computationally by the progression of a semi-infinite bubble in a narrow fluid-occluded channel. The extent of injury caused by bubble progression to pulmonary epithelial cells lining the channel was evaluated. Counterintuitively, cell damage increased with decreasing opening velocity. The presence of pulmonary surfactant, Infasurf, completely abated the injury. These results support the hypotheses that mechanical stresses associated with airway reopening injure pulmonary epithelial cells and that pulmonary surfactant protects the epithelium from this injury. Computational simulations identified the magnitudes of components of the stress cycle associated with airway reopening (shear stress, pressure, shear stress gradient, or pressure gradient) that may be injurious to the epithelial cells. By comparing these magnitudes to the observed damage, we conclude that the steep pressure gradient near the bubble front was the most likely cause of the observed cellular damage. PMID:12433851

  6. Computational modeling of unsteady surfactant-laden liquid plug propagation in neonatal airways

    NASA Astrophysics Data System (ADS)

    Olgac, Ufuk; Muradoglu, Metin

    2013-07-01

    Surfactant-free and surfactant-laden liquid plug propagation in neonatal airways in various generations representing the upper and lower airways are investigated computationally using a finite-difference/front-tracking method. Emphasis is placed on the unsteady surfactant-laden plug propagation as a model for Surfactant Replacement Therapy (SRT) and airway reopening. The numerical method is designed to solve the evolution equations of the interfacial and bulk surfactant concentrations coupled with the incompressible Navier-Stokes equations. Available experimental data for surfactant Survanta are used to relate surface tension coefficient to surfactant concentration at the interface. It is found that, for the surfactant-free case, the trailing film thickness is in good agreement with Taylor's law for plugs with plug length greater than the airway width. Mechanical stresses that could be injurious to epithelial cells such as pressure and shear stress and their gradients are maximized on the front and rear menisci with increasing magnitudes in the lower generations. These mechanical stresses, especially pressure and pressure gradient, are diminished with the introduction of surfactants. Surfactant is absorbed onto the trailing film and thickens it, eventually leading to either plug rupture or, if totally consumed prior to rupture, to steadily propagating plug. In the upper airways, initially small plugs rupture rapidly and plugs with comparable initial plug length with the airway width persist and propagate steadily. For a more effective SRT treatment, we recommend utilization of plugs with initial plug length greater than the airway width. Increasing surfactant strength or increasing the initially instilled surfactant concentration is found to be ineffective.

  7. Airway management in cervical spine injury

    PubMed Central

    Austin, Naola; Krishnamoorthy, Vijay; Dagal, Arman

    2014-01-01

    To minimize risk of spinal cord injury, airway management providers must understand the anatomic and functional relationship between the airway, cervical column, and spinal cord. Patients with known or suspected cervical spine injury may require emergent intubation for airway protection and ventilatory support or elective intubation for surgery with or without rigid neck stabilization (i.e., halo). To provide safe and efficient care in these patients, practitioners must identify high-risk patients, be comfortable with available methods of airway adjuncts, and know how airway maneuvers, neck stabilization, and positioning affect the cervical spine. This review discusses the risks and benefits of various airway management strategies as well as specific concerns that affect patients with known or suspected cervical spine injury. PMID:24741498

  8. Airway injury during high-level exercise.

    PubMed

    Kippelen, Pascale; Anderson, Sandra D

    2012-05-01

    Airway epithelial cells act as a physical barrier against environmental toxins and injury, and modulate inflammation and the immune response. As such, maintenance of their integrity is critical. Evidence is accumulating to suggest that exercise can cause injury to the airway epithelium. This seems the case particularly for competitive athletes performing high-level exercise, or when exercise takes place in extreme environmental conditions such as in cold dry air or in polluted air. Dehydration of the small airways and increased forces exerted on to the airway surface during severe hyperpnoea are thought to be key factors in determining the occurrence of injury of the airway epithelium. The injury-repair process of the airway epithelium may contribute to the development of the bronchial hyper-responsiveness that is documented in many elite athletes. PMID:22247295

  9. Three-dimensional fluid pressure mapping in porous media using magnetic resonance imaging with gas-filled liposomes.

    PubMed

    Morris, Robert H; Bencsik, Martin; Vangala, Anil K; Perrie, Yvonne

    2007-05-01

    This paper presents and demonstrates a method for using magnetic resonance imaging to measure local pressure of a fluid saturating a porous medium. The method is tested both in a static system of packed silica gel and in saturated sintered glass cylinders experiencing fluid flow. The fluid used contains 3% gas in the form of 3-mum average diameter gas filled 1,2-distearoyl-sn-glycero-3-phosphocholine (C18:0, MW: 790.16) liposomes suspended in 5% glycerol and 0.5% Methyl cellulose with water. Preliminary studies at 2.35 T demonstrate relative magnetic resonance signal changes of 20% per bar in bulk fluid for an echo time T(E)=40 ms, and 6-10% in consolidated porous media for T(E)=10 ms, over the range 0.8-1.8 bar for a spatial resolution of 0.1 mm(3) and a temporal resolution of 30 s. The stability of this solution with relation to applied pressure and methods for improving sensitivity are discussed. PMID:17466775

  10. A concept for transition mapping on a 10 deg-cone in the National Transonic Facility using flow-pressure variation

    NASA Technical Reports Server (NTRS)

    Gartenberg, Ehud

    1995-01-01

    A conceptual study was performed to define a technique for mapping the boundary-layer transition on a 10 deg-Cone in the National Transonic Facility (NTF) as a means of determining this cryogenic-tunnel suitability for laminar flow testing. A major challenge was to devise a test matrix using a fixed surface pitot probe, varying the flow pressure to pr oduce the actual Reynolds numbers for boundary-layer transition. This constraint resulted from a lack of a suitable and reliable electrical motor to drive the probe along the cone's surface under cryogenic flow conditions. The initial phase of this research was performed by the author in collaboration with the late Dr. William B. Igoe from the Aerodynamics Division at NASA Langley Research Center. His comments made during the drafting of this document were invaluable and a source of inspiration.

  11. Airway Assessment for Office Sedation/Anesthesia.

    PubMed

    Rosenberg, Morton B; Phero, James C

    2015-01-01

    Whenever a patient is about to receive sedation or general anesthesia, no matter what the technique, the preoperative assessment of the airway is one of the most important steps in ensuring patient safety and positive outcomes. This article, Part III in the series on airway management, is directed at the ambulatory office practice and focuses on predicting the success of advanced airway rescue techniques. PMID:26061578

  12. A bug's view of allergic airways disease.

    PubMed

    Hsu, Peter S; Campbell, Dianne E

    2016-06-01

    The increase in allergic airways disease has been linked to modern urbanization and lifestyle. Recent evidence suggests that the associated reduction in microbial exposure, reduction in dietary fibre intake and increased antibiotic use may cause early dysbiosis in infancy, which predisposes to immune dysregulation and allergic airways disease later in life. This implies that there may be a window of opportunity for primary prevention strategies aimed to protect or restore the microbiome early in life and thereby decrease the risk of developing allergic airways disease. Alternatively, strategies that correct dysbiosis may aid in the treatment of established allergic airways disease. PMID:27012478

  13. Airway vascular damage in elite swimmers.

    PubMed

    Moreira, André; Palmares, Carmo; Lopes, Cristina; Delgado, Luís

    2011-11-01

    We postulated that high level swimming can promote airway inflammation and thus asthma by enhancing local vascular permeability. We aimed to test this hypothesis by a cross-sectional study comparing swimmers (n = 13, 17 ± 3 years, competing 7 ± 4 years, training 18 ± 3 h per week), asthmatic-swimmers (n = 6, 17 ± 2 years, competing 8 ± 3 years, training 16 ± 4 h per week), and asthmatics (n = 19, 14 ± 3 years). Subjects performed induced sputum and had exhaled nitric oxide, lung volumes, and airway responsiveness determined. Airway vascular permeability index was defined as the ratio of albumin in sputum and serum. Results from the multiple linear regression showed each unit change in airway vascular permeability index was associated with an increase of 0.97% (95%CI: 0.02 to 1.92; p = 0.047) in sputum eosinophilis, and of 2.64% (95%CI:0.96 to 4.31; p = 0.006) in sputum neutrophils after adjustment for confounders. In a general linear model no significant differences between airway vascular permeability between index study groups existed, after controlling for sputum eosinophilis and neutrophils. In conclusion, competitive swimmers training in chlorine-rich pools have similar levels of airway vascular permeability than asthmatics. Although competitive swimming has been associated with asthma, airway inflammation and airway hyperesponsiveness do not seem to be dependent on increased airway vascular permeability. PMID:21669516

  14. Automated lobe-based airway labeling.

    PubMed

    Gu, Suicheng; Wang, Zhimin; Siegfried, Jill M; Wilson, David; Bigbee, William L; Pu, Jiantao

    2012-01-01

    Regional quantitative analysis of airway morphological abnormalities is of great interest in lung disease investigation. Considering that pulmonary lobes are relatively independent functional unit, we develop and test a novel and efficient computerized scheme in this study to automatically and robustly classify the airways into different categories in terms of pulmonary lobe. Given an airway tree, which could be obtained using any available airway segmentation scheme, the developed approach consists of four basic steps: (1) airway skeletonization or centerline extraction, (2) individual airway branch identification, (3) initial rule-based airway classification/labeling, and (4) self-correction of labeling errors. In order to assess the performance of this approach, we applied it to a dataset consisting of 300 chest CT examinations in a batch manner and asked an image analyst to subjectively examine the labeled results. Our preliminary experiment showed that the labeling accuracy for the right upper lobe, the right middle lobe, the right lower lobe, the left upper lobe, and the left lower lobe is 100%, 99.3%, 99.3%, 100%, and 100%, respectively. Among these, only two cases are incorrectly labeled due to the failures in airway detection. It takes around 2 minutes to label an airway tree using this algorithm. PMID:23093951

  15. Airway sonography in live models and cadavers.

    PubMed

    Tsui, Ban; Ip, Vivian; Walji, Anil

    2013-06-01

    Sonography using cadavers is beneficial in teaching and learning sonoanatomy, which is particularly important because imaging of the airway can be challenging due to the cartilaginous landmarks and air artifacts. In this exploratory study, we have attempted to compare the airway sonoanatomy of cadavers and live models. Our observations support the use of cadavers as teaching tools for learning airway sonoanatomy and practicing procedures involving airway structures, such as superior laryngeal nerve blocks, transtracheal injections, and needle cricothyroidotomy, before performance on patients in clinical situations. We believe this process will improve patient safety and enhance the competency of trainees and practitioners in rare procedures such as needle cricothyroidotomy. PMID:23716527

  16. Anatomic Optical Coherence Tomography of Upper Airways

    NASA Astrophysics Data System (ADS)

    Chin Loy, Anthony; Jing, Joseph; Zhang, Jun; Wang, Yong; Elghobashi, Said; Chen, Zhongping; Wong, Brian J. F.

    The upper airway is a complex and intricate system responsible for respiration, phonation, and deglutition. Obstruction of the upper airways afflicts an estimated 12-18 million Americans. Pharyngeal size and shape are important factors in the pathogenesis of airway obstructions. In addition, nocturnal loss in pharyngeal muscular tone combined with high pharyngeal resistance can lead to collapse of the airway and periodic partial or complete upper airway obstruction. Anatomical optical coherence tomography (OCT) has the potential to provide high-speed three-dimensional tomographic images of the airway lumen without the use of ionizing radiation. In this chapter we describe the methods behind endoscopic OCT imaging and processing to generate full three dimensional anatomical models of the human airway which can be used in conjunction with numerical simulation methods to assess areas of airway obstruction. Combining this structural information with flow dynamic simulations, we can better estimate the site and causes of airway obstruction and better select and design surgery for patients with obstructive sleep apnea.

  17. Substitution mapping in dahl rats identifies two distinct blood pressure quantitative trait loci within 1.12- and 1.25-mb intervals on chromosome 3.

    PubMed

    Lee, Soon Jin; Liu, Jun; Westcott, Allison M; Vieth, Joshua A; DeRaedt, Sarah J; Yang, Siming; Joe, Bina; Cicila, George T

    2006-12-01

    Substitution mapping was used to refine the localization of blood pressure (BP) quantitative trait loci (QTL) within the congenic region of S.R-Edn3 rats located at the q terminus of rat chromosome 3 (RNO3). An F2(SxS.R-Edn3) population (n=173) was screened to identify rats having crossovers within the congenic region of RNO3 and six congenic substrains were developed that carry shorter segments of R-rat-derived RNO3. Five of the six congenic substrains had significantly lower BP compared to the parental S rat. The lack of BP lowering effect demonstrated by the S.R(ET3x5) substrain and the BP lowering effect retained by the S.R(ET3x2) substrain together define the RNO3 BP QTL-containing region as approximately 4.64 Mb. Two nonoverlapping substrains, S.R(ET3x1) and S.R(ET3x6), had significantly lower BP compared to the S strain, indicating the presence of two distinct BP QTL in the RNO3 q terminus. The RNO3 q terminus was fine mapped with newly developed polymorphic markers to characterize the extent of the congenic regions. The two RNO3 BP QTL regions were thus defined as within intervals of 0.05-1.12 and 0.72-1.25 Mb, respectively. Also important was our difficulty in fine mapping and marker placement in this portion of the rat genome (and thus candidate gene identification) using the available genomic data, including the rat genome sequence. PMID:17028336

  18. Physical principle of airway design in human lungs

    NASA Astrophysics Data System (ADS)

    Park, Keunhwan; Son, Taeho; Kim, Wonjung; Kim, Ho-Young

    2014-11-01

    From an engineering perspective, lungs are natural microfluidic devices that extract oxygen from air. In the bronchial tree, airways branch by dichotomy with a systematic reduction of their diameters. It is generally accepted that in conducting airways, which air passes on the way to the acinar airways from the atmosphere, the reduction ratio of diameter is closely related to the minimization of viscous dissipation. Such a principle is formulated as the Hess-Murray law. However, in acinar airways, where oxygen transfer to alveolae occurs, the diameter reduction with progressive generations is more moderate than in conducting airways. Noting that the dominant transfer mechanism in acinar airways is diffusion rather than advection, unlike conducting airways, we construct a mathematical model for oxygen transfer through a series of acinar airways. Our model allows us to predict the optimal airway reduction ratio that maximizes the oxygen transfer in a finite airway volume, thereby rationalizing the observed airway reduction ratio in acinar airways.

  19. Computational fluid dynamics modeling of the upper airway of children with obstructive sleep apnea syndrome in steady flow.

    PubMed

    Xu, Chun; Sin, SangHun; McDonough, Joseph M; Udupa, Jayaram K; Guez, Allon; Arens, Raanan; Wootton, David M

    2006-01-01

    Computational fluid dynamic (CFD) analysis was used to model the effect of airway geometry on internal pressure in the upper airway of three children with obstructive sleep apnea syndrome (OSAS), and three controls. Model geometry was reconstructed from magnetic resonance images obtained during quiet tidal breathing, meshed with an unstructured grid, and solved at normative peak resting flow. The unsteady Reynolds-averaged Navier-Stokes equations were solved with steady flow boundary conditions in inspiration and expiration, using a two-equation low-Reynolds number turbulence model. Model results were validated using an in-vitro scale model, unsteady flow simulation, and reported nasal resistance measurements in children. Pharynx pressure drop strongly correlated to airway area restriction. Inspiratory pressure drop was primarily proportional to the square of flow, consistent with pressure losses due to convective acceleration caused by area restriction. On inspiration, in OSAS pressure drop occurred primarily between the choanae and the region where the adenoids overlap the tonsils (overlap region) due to airway narrowing, rather than in the nasal passages; in controls the majority of pressure drop was in the nasal passages. On expiration, in OSAS the majority of pressure drop occurred between the oropharynx (posterior to the tongue) and overlap region, and local minimum pressure in the overlap region was near atmospheric due to pressure recovery in the anterior nasopharynx. The results suggest that pharyngeal airway shape in children with OSAS significantly affects internal pressure distribution compared to nasal resistance. The model may also help explain regional dynamic airway narrowing during expiration. PMID:16098533

  20. 21 CFR 868.1750 - Pressure plethysmograph.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Pressure plethysmograph. 868.1750 Section 868.1750...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1750 Pressure plethysmograph. (a) Identification. A pressure plethysmograph is a device used to determine a patient's airway resistance and...

  1. 21 CFR 868.1750 - Pressure plethysmograph.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pressure plethysmograph. 868.1750 Section 868.1750...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1750 Pressure plethysmograph. (a) Identification. A pressure plethysmograph is a device used to determine a patient's airway resistance and...

  2. 21 CFR 868.1750 - Pressure plethysmograph.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Pressure plethysmograph. 868.1750 Section 868.1750...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1750 Pressure plethysmograph. (a) Identification. A pressure plethysmograph is a device used to determine a patient's airway resistance and...

  3. 21 CFR 868.1750 - Pressure plethysmograph.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Pressure plethysmograph. 868.1750 Section 868.1750...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1750 Pressure plethysmograph. (a) Identification. A pressure plethysmograph is a device used to determine a patient's airway resistance and...

  4. 21 CFR 868.1750 - Pressure plethysmograph.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Pressure plethysmograph. 868.1750 Section 868.1750...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1750 Pressure plethysmograph. (a) Identification. A pressure plethysmograph is a device used to determine a patient's airway resistance and...

  5. Partitioning of airway and respiratory tissue mechanical impedances by body plethysmography.

    PubMed

    Peslin, R; Duvivier, C

    1998-02-01

    We have tested the feasibility of separating the airway (Zaw) and tissue (Zti) components of total respiratory input impedance (Zrs,in) in healthy subjects by measuring alveolar gas compression by body plethysmography (Vpl) during pressure oscillations at the airway opening. The forced oscillation set up was placed inside a body plethysmograph, and the subjects rebreathed BTPS gas. Zrs,in and the relationship between Vpl and airway flow (Hpl) were measured from 4 to 29 Hz. Zaw and Zti were computed from Zrs,in and Hpl by using the monoalveolar T-network model and alveolar gas compliance derived from thoracic gas volume. The data were in good agreement with previous observations: airways and tissue resistance exhibited some positive and negative frequency dependences, respectively; airway reactance was consistent with an inertance of 0.015 +/- 0.003 hPa.s2.l-1 and tissue reactance with an elastance of 36 +/- 8 hPa/I. The changes seen with varying lung volume, during elastic loading of the chest and during bronchoconstriction, were mostly in agreement with the expected effects. The data, as well as computer simulation, suggest that the partitioning is unaffected by mechanical inhomogeneity and only moderately affected by airway wall shunting. PMID:9475865

  6. Effect of ozone exposure on antigen-induced airway hyperresponsiveness in guinea pigs

    SciTech Connect

    Vargas, M.H.; Segura, P.; Campos, M.G.; Hong, E.; Montano, L.M.

    1994-12-31

    Airway hyperresponsiveness can be induced by several stimuli including antigen and ozone, both of which may be present in the air of polluted cities. Though the effect of ozone on the bronchoconstrictor response to antigen has been well described, the combined effect of these stimuli on airway hyperresponsiveness has not yet been studied. Sensitized guinea pigs with or without ozone exposure for 1 h at 3 ppm, 18 h prior to study, were challenged with a dose-response curve to histamine (0.01-1.8 {mu}g/kg, iv), and then by a second histamine dose-response curve 1 h later. Airway responses were measured as the increase in pulmonary insufflation pressure. In sensitized guinea pigs, the histamine ED50 significantly decreased after antigen challenge, demonstrating the development of airway hyperresponsiveness. Sensitized guinea pigs exposed to ozone showed airway hyperresponsiveness to histamine when compared with nonexposed animals, and such hyperresponsiveness was further enhanced after antigen challenge. We conclude that in this guinea pig model of acute allergic bronchoconstriction both antigen challenge and ozone induce airway hyperresponsiveness, while ozone exposure does not modify the development of antigen-induced hyperresponsiveness. 25 refs., 1 fig., 1 tab.

  7. Effects of Race on Upper Airway Dynamic Function During Sleep in Children

    PubMed Central

    Pinto, Swaroop; Huang, Jingtao; Tapia, Ignacio; Karamessinis, Laurie; Pepe, Michelle; Gallagher, Paul R.; Bradford, Ruth; Nixon, Tomas; Lee, Ngoon-Yin; Marcus, Carole L.

    2011-01-01

    Study Objective: Studies in adults and children have shown that African American race is a risk factor for the obstructive sleep apnea syndrome (OSAS). Therefore, we hypothesized that non-obese, non-snoring African American children would have a more collapsible upper airway during sleep than age-, gender-, and size-matched Caucasians. Design: Upper airway dynamic function was measured during sleep in normal African American and Caucasian children. Setting: Sleep laboratory. Patients or Participants: 56 normal children between the ages of 8-18 years. Interventions: Pressure-flow relationships were measured during NREM sleep. Nasal pressure was decreased to subatmospheric levels, using previously described techniques that resulted in an activated and relatively hypotonic upper airway. Measurements and Results: The activated and hypotonic critical pressures (Pcrit) were -25 (-25, -3) (median, range) and -19 (-25, -3) for African Americans, and -25 (-25, -4) and -25 (-25.0, -4) cm H2O, respectively, for Caucasians. The slopes of the pressure-flow response (SPF) under activated and hypotonic conditions for African Americans were 10 (-9, 46) and 13 (-20, 46), and for Caucasians 9 (-9, 64) and 8 (-5, 54) mL/s/cm H2O, respectively. There were no significant differences between groups for Pcrit or SPF under either activated or hypotonic conditions. Conclusion: Upper airway collapsibility was similar in asymptomatic, non-obese African American and Caucasian children. Differences in upper airway characteristics and neuromotor function cannot explain the increased prevalence of OSAS in African American children. Citation: Pinto S; Huang J; Tapia I; Karamessinis L; Pepe M; Gallagher PR; Bradford R; Nixon T; Lee NY; Marcus CL. Effects of race on upper airway dynamic function during sleep in children. SLEEP 2011;34(4):495-501. PMID:21461328

  8. Peripheral airways obstruction in idiopathic pulmonary artery hypertension (primary).

    PubMed

    Fernandez-Bonetti, P; Lupi-Herrera, E; Martinez-Guerra, M L; Barrios, R; Seoane, M; Sandoval, J

    1983-05-01

    The mechanical properties of the lung were studied in ten nonsmokers with idiopathic pulmonary artery hypertension (IPAH) (mean pulmonary artery pressure 65.7 +/- 30 mm Hg). In the routine lung test, residual volume was found to be abnormal (greater than 120 percent of the predicted) in seven patients, and measured airway resistance was normal in eight out of the ten patients. A decreased FEF 75-85 percent, abnormal values for the helium-air flow ratios and increased closing capacities were documented in eight of ten patients in whom lung elastic recoil was normal (six of ten) or increased (four of ten). These features suggest peripheral airways obstruction (PAO) which was also supported by histopathologic findings in three cases (one biopsy and two necropsies). The observed changes in lung compliance could be related to the behavior of the coupling of the air-space and vascular compartments. The etiology of PAO in IPAH patients is not known, but our results indicate that both the peripheral airways and the pulmonary circulation are affected. The knowledge of PAO in IPAH patients could help to better understand the observed V/Q inequality in this entity. PMID:6839814

  9. Airway blood flow response to dry air hyperventilation in sheep

    SciTech Connect

    Parsons, G.H.; Baile, E.M.; Pare, P.D.

    1986-03-01

    Airway blood flow (Qaw) may be important in conditioning inspired air. To determine the effect of eucapneic dry air hyperventilation (hv) on Qaw in sheep the authors studied 7 anesthetized open-chest sheep after 25 min. of warm dry air hv. During each period of hv the authors have recorded vascular pressures, cardiac output (CO), and tracheal mucosal and inspired air temperature. Using a modification of the reference flow technique radiolabelled microspheres were injected into the left atrium to make separate measurements after humid air and dry air hv. In 4 animals a snare around the left main pulmonary artery was used following microsphere injection to prevent recirculation (entry into L lung of microspheres from the pulmonary artery). Qaw to the trachea and L lung as measured and Qaw for the R lung was estimated. After the final injection the sheep were killed and bronchi (Br) and lungs removed. Qaw (trachea plus L lung plus R lung) in 4 sheep increased from a mean of 30.8 to 67.0 ml/min. Airway mucosal temp. decreased from 39/sup 0/ to 33/sup 0/C. The authors conclude that dry air hv cools airway mucosa and increases Qaw in sheep.

  10. Transient motion of mucus plugs in respiratory airways

    NASA Astrophysics Data System (ADS)

    Zamankhan, Parsa; Hu, Yingying; Helenbrook, Brian; Takayama, Shuichi; Grotberg, James B.

    2011-11-01

    Airway closure occurs in lung diseases such as asthma, cystic fibrosis, or emphysema which have an excess of mucus that forms plugs. The reopening process involves displacement of mucus plugs in the airways by the airflow of respiration. Mucus is a non-Newtonian fluid with a yield stress; therefore its behavior can be approximated by a Bingham fluid constitutive equation. In this work the reopening process is approximated by simulation of a transient Bingham fluid plug in a 2D channel. The governing equations are solved by an Arbitrary Lagrangian Eulerian (ALE) finite element method through an in-house code. The constitutive equation for the Bingham fluid is implemented through a regularization method. The effects of the yield stress on the flow features and wall stresses are discussed with applications to potential injuries to the airway epithelial cells which form the wall. The minimum driving pressure for the initiation of the motion is computed and its value is related to the mucus properties and the plug shape. Supported by HL84370 and HL85156.

  11. Effects of tracheal airway occlusion on hyoid muscle length and upper airway volume.

    PubMed

    van Lunteren, E; Haxhiu, M A; Cherniack, N S

    1989-12-01

    Complex relationships exist among electromyograms (EMGs) of the upper airway muscles, respective changes in muscle length, and upper airway volume. To test the effects of preventing lung inflation on these relationships, recordings were made of EMGs and length changes of the geniohyoid (GH) and sternohyoid (SH) muscles as well as of tidal changes in upper airway volume in eight anesthetized cats. During resting breathing, tracheal airway occlusion tended to increase the inspiratory lengthening of GH and SH. In response to progressive hypercapnia, the GH eventually shortened during inspiration in all animals; the extent of muscle shortening was minimally augmented by airway occlusion despite substantial increases in EMGs. SH lengthened during inspiration in six of eight animals under hypercapnic conditions, and in these cats lengthening was greater during airway occlusion even though EMGs increased. Despite the above effects on SH and GH length, upper airway tidal volume was increased significantly by tracheal occlusion under hypercapnic conditions. These data suggest that the thoracic and upper airway muscle reflex effects of preventing lung inflation during inspiration act antagonistically on hyoid muscle length, but, because of the mechanical arrangement of the hyoid muscles relative to the airway and thorax, they act agonistically to augment tidal changes in upper airway volume. The augmentation of upper airway tidal volume may occur in part as a result of the effects of thoracic movements being passively transmitted through the hyoid muscles. PMID:2606835

  12. Airway smooth muscle dynamics: a common pathway of airway obstruction in asthma

    PubMed Central

    An, S.S.; Bai, T.R.; Bates, J.H.T.; Black, J.L.; Brown, R.H.; Brusasco, V.; Chitano, P.; Deng, L.; Dowell, M.; Eidelman, D.H.; Fabry, B.; Fairbank, N.J.; Ford, L.E.; Fredberg, J.J.; Gerthoffer, W.T.; Gilbert, S.H.; Gosens, R.; Gunst, S.J.; Halayko, A.J.; Ingram, R.H.; Irvin, C.G.; James, A.L.; Janssen, L.J.; King, G.G.; Knight, D.A.; Lauzon, A.M.; Lakser, O.J.; Ludwig, M.S.; Lutchen, K.R.; Maksym, G.N.; Martin, J.G.; Mauad, T.; McParland, B.E.; Mijailovich, S.M.; Mitchell, H.W.; Mitchell, R.W.; Mitzner, W.; Murphy, T.M.; Paré, P.D.; Pellegrino, R.; Sanderson, M.J.; Schellenberg, R.R.; Seow, C.Y.; Silveira, P.S.P.; Smith, P.G.; Solway, J.; Stephens, N.L.; Sterk, P.J.; Stewart, A.G.; Tang, D.D.; Tepper, R.S.; Tran, T.; Wang, L.

    2008-01-01

    Excessive airway obstruction is the cause of symptoms and abnormal lung function in asthma. As airway smooth muscle (ASM) is the effecter controlling airway calibre, it is suspected that dysfunction of ASM contributes to the pathophysiology of asthma. However, the precise role of ASM in the series of events leading to asthmatic symptoms is not clear. It is not certain whether, in asthma, there is a change in the intrinsic properties of ASM, a change in the structure and mechanical properties of the noncontractile components of the airway wall, or a change in the interdependence of the airway wall with the surrounding lung parenchyma. All these potential changes could result from acute or chronic airway inflammation and associated tissue repair and remodelling. Anti-inflammatory therapy, however, does not “cure” asthma, and airway hyperresponsiveness can persist in asthmatics, even in the absence of airway inflammation. This is perhaps because the therapy does not directly address a fundamental abnormality of asthma, that of exaggerated airway narrowing due to excessive shortening of ASM. In the present study, a central role for airway smooth muscle in the pathogenesis of airway hyperresponsiveness in asthma is explored. PMID:17470619

  13. Athletic Trainers' Knowledge Regarding Airway Adjuncts

    ERIC Educational Resources Information Center

    Edler, Jessica R.; Eberman, Lindsey E.; Kahanov, Leamor; Roman, Christopher; Mata, Heather Lynne

    2015-01-01

    Context: Research suggests that knowledge gaps regarding the appropriate use of airway adjuncts exist among various health care practitioners, and that knowledge is especially limited within athletic training. Objective: To determine the relationship between perceived knowledge (PK) and actual knowledge (AK) of airway adjunct use and the…

  14. SUBCHRONIC ENDOTOXIN INHALATION CAUSES PERSISTENT AIRWAY DISEASE

    EPA Science Inventory

    ABSTRACT

    The endotoxin component of organic dusts causes acute reversible airflow obstruction and airway inflammation. To test the hypothesis that endotoxin alone causes airway remodeling, we have compared the response of two inbred mouse strains to subchronic endotoxin ...

  15. Airway and Extracellular Matrix Mechanics in COPD

    PubMed Central

    Bidan, Cécile M.; Veldsink, Annemiek C.; Meurs, Herman; Gosens, Reinoud

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) is one of the most common lung diseases worldwide, and is characterized by airflow obstruction that is not fully reversible with treatment. Even though airflow obstruction is caused by airway smooth muscle contraction, the extent of airway narrowing depends on a range of other structural and functional determinants that impact on active and passive tissue mechanics. Cells and extracellular matrix in the airway and parenchymal compartments respond both passively and actively to the mechanical stimulation induced by smooth muscle contraction. In this review, we summarize the factors that regulate airway narrowing and provide insight into the relative contributions of different constituents of the extracellular matrix and their biomechanical impact on airway obstruction. We then review the changes in extracellular matrix composition in the airway and parenchymal compartments at different stages of COPD, and finally discuss how these changes impact airway narrowing and the development of airway hyperresponsiveness. Finally, we position these data in the context of therapeutic research focused on defective tissue repair. As a conclusion, we propose that future works should primarily target mild or early COPD, prior to the widespread structural changes in the alveolar compartment that are more characteristic of severe COPD. PMID:26696894

  16. 21 CFR 868.5100 - Nasopharyngeal airway.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway....

  17. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Oropharyngeal airway. 868.5110 Section 868.5110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway....

  18. 21 CFR 868.5100 - Nasopharyngeal airway.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway....

  19. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Oropharyngeal airway. 868.5110 Section 868.5110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway....

  20. 21 CFR 868.5100 - Nasopharyngeal airway.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway....

  1. 21 CFR 868.5100 - Nasopharyngeal airway.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway....

  2. 21 CFR 868.5110 - Oropharyngeal airway.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Oropharyngeal airway. 868.5110 Section 868.5110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5110 Oropharyngeal airway....

  3. 21 CFR 868.5100 - Nasopharyngeal airway.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nasopharyngeal airway. 868.5100 Section 868.5100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5100 Nasopharyngeal airway....

  4. Trefoil factor-2 reverses airway remodeling changes in allergic airways disease.

    PubMed

    Royce, Simon G; Lim, Clarice; Muljadi, Ruth C; Samuel, Chrishan S; Ververis, Katherine; Karagiannis, Tom C; Giraud, Andrew S; Tang, Mimi L K

    2013-01-01

    Trefoil factor 2 (TFF2) is a small peptide with an important role in mucosal repair. TFF2 is up-regulated in asthma, suggesting a role in asthma pathogenesis. Given its known biological role in promoting epithelial repair, TFF2 might be expected to exert a protective function in limiting the progression of airway remodeling in asthma. The contribution of TFF2 to airway remodeling in asthma was investigated by examining the expression of TFF2 in the airway and lung, and evaluating the effects of recombinant TFF2 treatment on established airway remodeling in a murine model of chronic allergic airways disease (AAD). BALB/c mice were sensitized and challenged with ovalbumin (OVA) or saline for 9 weeks, whereas mice with established OVA-induced AAD were treated with TFF2 or vehicle control (intranasally for 14 d). Effects on airway remodeling, airway inflammation, and airway hyperresponsiveness were then assessed, whereas TFF2 expression was determined by immunohistochemistry. TFF2 expression was significantly increased in the airways of mice with AAD, compared with expression levels in control mice. TFF2 treatment resulted in reduced epithelial thickening, subepithelial collagen deposition, goblet-cell metaplasia, bronchial epithelium apoptosis, and airway hyperresponsiveness (all P < 0.05, versus vehicle control), but TFF2 treatment did not influence airway inflammation. The increased expression of endogenous TFF2 in response to chronic allergic inflammation is insufficient to prevent the progression of airway inflammation and remodeling in a murine model of chronic AAD. However, exogenous TFF2 treatment is effective in reversing aspects of established airway remodeling. TFF2 has potential as a novel treatment for airway remodeling in asthma. PMID:22652198

  5. Difficult Airway Response Team: A Novel Quality Improvement Program for Managing Hospital-Wide Airway Emergencies

    PubMed Central

    Mark, Lynette J.; Herzer, Kurt R.; Cover, Renee; Pandian, Vinciya; Bhatti, Nasir I.; Berkow, Lauren C.; Haut, Elliott R.; Hillel, Alexander T.; Miller, Christina R.; Feller-Kopman, David J.; Schiavi, Adam J.; Xie, Yanjun J.; Lim, Christine; Holzmueller, Christine; Ahmad, Mueen; Thomas, Pradeep; Flint, Paul W.; Mirski, Marek A.

    2015-01-01

    Background Difficult airway cases can quickly become emergencies, increasing the risk of life-threatening complications or death. Emergency airway management outside the operating room is particularly challenging. Methods We developed a quality improvement program—the Difficult Airway Response Team (DART)—to improve emergency airway management outside the operating room. DART was implemented by a team of anesthesiologists, otolaryngologists, trauma surgeons, emergency medicine physicians, and risk managers in 2005 at The Johns Hopkins Hospital in Baltimore, Maryland. The DART program had three core components: operations, safety, and education. The operations component focused on developing a multidisciplinary difficult airway response team, standardizing the emergency response process, and deploying difficult airway equipment carts throughout the hospital. The safety component focused on real-time monitoring of DART activations and learning from past DART events to continuously improve system-level performance. This objective entailed monitoring the paging system, reporting difficult airway events and DART activations to a web-based registry, and using in situ simulations to identify and mitigate defects in the emergency airway management process. The educational component included development of a multispecialty difficult airway curriculum encompassing case-based lectures, simulation, and team building/communication to ensure consistency of care. Educational materials were also developed for non-DART staff and patients to inform them about the needs of patients with difficult airways and ensure continuity of care with other providers after discharge. Results Between July 2008 and June 2013, DART managed 360 adult difficult airway events comprising 8% of all code activations. Predisposing patient factors included body mass index > 40, history of head and neck tumor, prior difficult intubation, cervical spine injury, airway edema, airway bleeding, and previous

  6. Airway tissue engineering for congenital laryngotracheal disease.

    PubMed

    Maughan, Elizabeth; Lesage, Flore; Butler, Colin R; Hynds, Robert E; Hewitt, Richard; Janes, Sam M; Deprest, Jan A; Coppi, Paolo De

    2016-06-01

    Regenerative medicine offers hope of a sustainable solution for severe airway disease by the creation of functional, immunocompatible organ replacements. When considering fetuses and newborns, there is a specific spectrum of airway pathologies that could benefit from cell therapy and tissue engineering applications. While hypoplastic lungs associated with congenital diaphragmatic hernia (CDH) could benefit from cellular based treatments aimed at ameliorating lung function, patients with upper airway obstruction could take advantage from a de novo tissue engineering approach. Moreover, the international acceptance of the EXIT procedure as a means of securing the precarious neonatal airway, together with the advent of fetal surgery as a method of heading off postnatal co-morbidities, offers the revolutionary possibility of extending the clinical indication for tissue-engineered airway transplantation to infants affected by diverse severe congenital laryngotracheal malformations. This article outlines the necessary basic components for regenerative medicine solutions in this potential clinical niche. PMID:27301606

  7. Regulation of human airway surface liquid.

    PubMed

    Widdicombe, J H; Widdicombe, J G

    1995-01-01

    Human airways are lined with a film of liquid from 5-100 microns in depth, consisting of a periciliary sol around and a mucous gel above the cilia. Microscopical studies have shown the sol to be invariably the same depth as the length of the cilia, and we discuss possible reasons for this. The composition and sources of the airway surface liquid are also described. In addition the forces regulating its volume are analyzed. Several airway diseases are characterised by dramatic changes in the volume and composition of airway liquid. We review recent research suggesting that the accumulation of airway mucous secretions in cystic fibrosis is caused by alterations in active transport of ions and water across both the surface and gland epithelia. PMID:7740210

  8. Awake Craniotomy: A New Airway Approach.

    PubMed

    Sivasankar, Chitra; Schlichter, Rolf A; Baranov, Dimitry; Kofke, W Andrew

    2016-02-01

    Awake craniotomies have been performed regularly at the University of Pennsylvania since 2004. Varying approaches to airway management are described for this procedure, including intubation with an endotracheal tube and use of a laryngeal mask airway, simple facemask, or nasal cannula. In this case series, we describe the successful use (i.e., no need for endotracheal intubation related to inadequate gas exchange) of bilateral nasopharyngeal airways in 90 patients undergoing awake craniotomies. The use of nasopharyngeal airways can ease the transition between the asleep and awake phases of the craniotomy without the need to stimulate the airway. Our purpose was to describe our experience and report adverse events related to this technique. PMID:26579845

  9. Airway fires during surgery: Management and prevention

    PubMed Central

    Akhtar, Navaid; Ansar, Farrukh; Baig, Mirza Shahzad; Abbas, Akbar

    2016-01-01

    Airway fires pose a serious risk to surgical patients. Fires during surgery have been reported for many years with flammable anesthetic agents being the main culprits in the past. Association of airway fires with laser surgery is well-recognized, but there are reports of endotracheal tube fires ignited by electrocautery during pharyngeal surgery or tracheostomy or both. This uncommon complication has potentially grave consequences. While airway fires are relatively uncommon occurrences, they are very serious and can often be fatal. Success in preventing such events requires a thorough understanding of the components leading to a fire (fuel, oxidizer, and ignition source), as well as good communication between all members present to appropriately manage the fire and ensure patient safety. We present a case of fire in the airway during routine adenotonsillectomy. We will review the causes, preventive measures, and brief management for airway fires. PMID:27006554

  10. Anaesthetic management of acute airway obstruction

    PubMed Central

    Wong, Patrick; Wong, Jolin; Mok, May Un Sam

    2016-01-01

    The acutely obstructed airway is a medical emergency that can potentially result in serious morbidity and mortality. Apart from the latest advancements in anaesthetic techniques, equipment and drugs, publications relevant to our topic, including the United Kingdom’s 4th National Audit Project on major airway complications in 2011 and the updated American Society of Anesthesiologists’ difficult airway algorithm of 2013, have recently been published. The former contained many reports of adverse events associated with the management of acute airway obstruction. By analysing the data and concepts from these two publications, this review article provides an update on management techniques for the acutely obstructed airway. We discuss the principles and factors relevant to the decision-making process in formulating a logical management plan. PMID:26996162

  11. Anaesthetic management of acute airway obstruction.

    PubMed

    Wong, Patrick; Wong, Jolin; Mok, May Un Sam

    2016-03-01

    The acutely obstructed airway is a medical emergency that can potentially result in serious morbidity and mortality. Apart from the latest advancements in anaesthetic techniques, equipment and drugs, publications relevant to our topic, including the United Kingdom's 4th National Audit Project on major airway complications in 2011 and the updated American Society of Anesthesiologists' difficult airway algorithm of 2013, have recently been published. The former contained many reports of adverse events associated with the management of acute airway obstruction. By analysing the data and concepts from these two publications, this review article provides an update on management techniques for the acutely obstructed airway. We discuss the principles and factors relevant to the decision-making process in formulating a logical management plan. PMID:26996162

  12. Vocal Function and Upper Airway Thermoregulation in Five Different Environmental Conditions

    ERIC Educational Resources Information Center

    Sandage, Mary J.; Connor, Nadine P.; Pascoe, David D.

    2014-01-01

    Purpose: Phonation threshold pressure and perceived phonatory effort were hypothesized to increase and upper airway temperature to decrease following exposure to cold and/or dry air. Greater changes were expected with mouth versus nose breathing. Method: In a within-participant repeated measures design, 15 consented participants (7 men, 8 women)…

  13. Investigating the geometry of pig airways using computed tomography

    NASA Astrophysics Data System (ADS)

    Mansy, Hansen A.; Azad, Md Khurshidul; McMurray, Brandon; Henry, Brian; Royston, Thomas J.; Sandler, Richard H.

    2015-03-01

    Numerical modeling of sound propagation in the airways requires accurate knowledge of the airway geometry. These models are often validated using human and animal experiments. While many studies documented the geometric details of the human airways, information about the geometry of pig airways is scarcer. In addition, the morphology of animal airways can be significantly different from that of humans. The objective of this study is to measure the airway diameter, length and bifurcation angles in domestic pigs using computed tomography. After imaging the lungs of 3 pigs, segmentation software tools were used to extract the geometry of the airway lumen. The airway dimensions were then measured from the resulting 3 D models for the first 10 airway generations. Results showed that the size and morphology of the airways of different animals were similar. The measured airway dimensions were compared with those of the human airways. While the trachea diameter was found to be comparable to the adult human, the diameter, length and branching angles of other airways were noticeably different from that of humans. For example, pigs consistently had an early airway branching from the trachea that feeds the superior (top) right lung lobe proximal to the carina. This branch is absent in the human airways. These results suggested that the human geometry may not be a good approximation of the pig airways and may contribute to increasing the errors when the human airway geometric values are used in computational models of the pig chest.

  14. Intrathoracic airway measurement: ex-vivo validation

    NASA Astrophysics Data System (ADS)

    Reinhardt, Joseph M.; Raab, Stephen A.; D'Souza, Neil D.; Hoffman, Eric A.

    1997-05-01

    High-resolution x-ray CT (HRCT) provides detailed images of the lungs and bronchial tree. HRCT-based imaging and quantitation of peripheral bronchial airway geometry provides a valuable tool for assessing regional airway physiology. Such measurements have been sued to address physiological questions related to the mechanics of airway collapse in sleep apnea, the measurement of airway response to broncho-constriction agents, and to evaluate and track the progression of disease affecting the airways, such as asthma and cystic fibrosis. Significant attention has been paid to the measurements of extra- and intra-thoracic airways in 2D sections from volumetric x-ray CT. A variety of manual and semi-automatic techniques have been proposed for airway geometry measurement, including the use of standardized display window and level settings for caliper measurements, methods based on manual or semi-automatic border tracing, and more objective, quantitative approaches such as the use of the 'half-max' criteria. A recently proposed measurements technique uses a model-based deconvolution to estimate the location of the inner and outer airway walls. Validation using a plexiglass phantom indicates that the model-based method is more accurate than the half-max approach for thin-walled structures. In vivo validation of these airway measurement techniques is difficult because of the problems in identifying a reliable measurement 'gold standard.' In this paper we report on ex vivo validation of the half-max and model-based methods using an excised pig lung. The lung is sliced into thin sections of tissue and scanned using an electron beam CT scanner. Airways of interest are measured from the CT images, and also measured with using a microscope and micrometer to obtain a measurement gold standard. The result show no significant difference between the model-based measurements and the gold standard; while the half-max estimates exhibited a measurement bias and were significantly

  15. Evaluation of airway blocks versus general anaesthesia for diagnostic direct laryngoscopy and biopsy for carcinoma larynx.

    PubMed

    Trivedi, Vandana; Sharma, Gunjan

    2012-02-01

    A prospective randomised study of 100 patients divided into two groups was done to compare the effects of regional airway nerve blocks versus general anaesthesia to evaluate intra-operative haemodynamic changes and compare the level of postoperative analgesia and sedation in both the groups. In group I whole airway block including bilateral superior laryngeal nerve block with bilateral glossopharyngeal block and recurrent laryngeal nerve block was given and in group II general anaesthesia was given. The mean duration was 27 +/- 5 minutes in all cases, all patients were of ASA grade 3 or 4. Baseline and pre-operative values of pulse and blood pressure were noted and were recorded at 0, 5, 7, 9, 10 and 15 minutes. Postoperative sedation and VAS scores were recorded at 0, 5, 15 and 30 minutes initially and then hourly. The present study showed significant haemodyanamic changes in group II with significant rise in mean arterial pressure and pulse rate during peri-operative period. Whereas in group I there was a stability in mean arterial pressure and pulse rate peri-operatively. The postoperative analgesia was significantly higher in group I and lasted longer as compared to group II and patients were less agitated and calm as assessed by the sedation score, in group II most of the patients required postoperative nebulisation as compared to group I where no patient needed nebulisation. In conclusion we suggest that regional airway block for anaesthesia in the short procedures of upper airways and also in cases of predicting difficult airway cases for securing the safe airway can be very useful alternate to general anaesthesia. PMID:23029839

  16. Allergic airways disease develops after an increase in allergen capture and processing in the airway mucosa.

    PubMed

    von Garnier, Christophe; Wikstrom, Matthew E; Zosky, Graeme; Turner, Debra J; Sly, Peter D; Smith, Miranda; Thomas, Jennifer A; Judd, Samantha R; Strickland, Deborah H; Holt, Patrick G; Stumbles, Philip A

    2007-11-01

    Airway mucosal dendritic cells (AMDC) and other airway APCs continuously sample inhaled Ags and regulate the nature of any resulting T cell-mediated immune response. Although immunity develops to harmful pathogens, tolerance arises to nonpathogenic Ags in healthy individuals. This homeostasis is thought to be disrupted in allergic respiratory disorders such as allergic asthma, such that a potentially damaging Th2-biased, CD4(+) T cell-mediated inflammatory response develops against intrinsically nonpathogenic allergens. Using a mouse model of experimental allergic airways disease (EAAD), we have investigated the functional changes occurring in AMDC and other airway APC populations during disease onset. Onset of EAAD was characterized by early and transient activation of airway CD4(+) T cells coinciding with up-regulation of CD40 expression exclusively on CD11b(-) AMDC. Concurrent enhanced allergen uptake and processing occurred within all airway APC populations, including B cells, macrophages, and both CD11b(+) and CD11b(-) AMDC subsets. Immune serum transfer into naive animals recapitulated the enhanced allergen uptake observed in airway APC populations and mediated activation of naive allergen-specific, airway CD4(+) T cells following inhaled allergen challenge. These data suggest that the onset of EAAD is initiated by enhanced allergen capture and processing by a number of airway APC populations and that allergen-specific Igs play a role in the conversion of normally quiescent AMDC subsets into those capable of inducing airway CD4(+) T cell activation. PMID:17947647

  17. Implantation of a defibrillator in a patient with an upper airway stimulation device.

    PubMed

    Ong, Adrian A; O'Brien, Terrence X; Nguyen, Shaun A; Gillespie, M Boyd

    2016-02-01

    The patient is a 62-year-old man with continuous positive airway pressure-intolerant obstructive sleep apnea who was enrolled in a study for a hypoglossal nerve upper airway stimulation device (UAS). Nearly 2.5 years later, he was admitted to the hospital for unstable angina. Diagnostic workup revealed a prior myocardial infarction, an ejection fraction of 30% on maximal medical therapy, and episodes of nonsustained ventricular tachycardia. During hospitalization, the patient received an implantable cardioverter defibrillator (ICD). This is the first reported case of simultaneous use of a UAS and an ICD, and we report no untoward device interference between the two implantable devices. PMID:26403681

  18. Educating the Educator: Teaching Airway Adjunct Techniques in Athletic Training

    ERIC Educational Resources Information Center

    Berry, David C.; Seitz, S. Robert

    2011-01-01

    The 5th edition of the "Athletic Training Education Competencies" ("Competencies") now requires athletic training educators (ATEs) to introduce into the curriculum various types of airway adjuncts including: (1) oropharyngeal airways (OPA), (2) nasopharyngeal airways (NPA), (3) supraglottic airways (SGA), and (4) suction. The addition of these…

  19. Small particles disrupt postnatal airway development

    PubMed Central

    Lee, DongYoub; Wallis, Chris; Schelegle, Edward S.; Van Winkle, Laura S.; Plopper, Charles G.; Fanucchi, Michelle V.; Kumfer, Ben; Kennedy, Ian M.; Chan, Jackie K. W.

    2010-01-01

    Increasing numbers of epidemiologic studies associate air pollution exposure in children with decreased lung function development. The objective of this study was to examine the effects of exposure to combustion-generated fine [230 and 212 nm number mean aerodynamic particle diameter (NMAD)] to ultrafine (73 nm NMAD) particles differing in elemental (EC) and organic (OC) carbon content on postnatal airway development in rats. Neonatal Sprague-Dawley rats were exposed from postnatal day 7 through 25, and lung function and airway architecture were evaluated 81 days of age. In a separate group of rats, cell proliferation was examined after a single particle exposure at 7 days of age. Early life exposure to 73 nm high OC/EC particles altered distal airway architecture and resulted in subtle changes in lung mechanics. Early life exposure to 212 nm high OC/EC particles did not alter lung architecture but did alter lung mechanics in a manner suggestive of central airway changes. In contrast, early life exposure to 230 nm low OC/EC particles did not alter lung architecture or mechanics. A single 6-h exposure to 73 nm high OC/EC particle decreased airway cell proliferation, whereas 212 nm high OC/EC particles increased it and 230 nm low OC/EC particles did not. The early life exposure to ultrafine, high OC/EC particles results in persistent alterations in distal airway architecture that is characterized by an initial decrease in airway cell proliferation. PMID:20634362

  20. Lung Transplantation: The State of the Airways.

    PubMed

    Husain, Aliya N; Garrity, Edward R

    2016-03-01

    Context .- Lung transplantation has become a viable option for definitive treatment of several end-stage lung diseases for which there are no other options available. However, long-term survival continues to be limited by chronic lung allograft dysfunction, which primarily affects the airways. Objective . -To highlight the complications occurring mainly in the airways of the lung transplant recipient from the early to late posttransplant periods. Data Sources .- Review literature focusing on the airways in patients with lung transplants and clinical experience of the authors. Conclusions .- Postsurgical complications and infections of the airways have decreased because of better techniques and management. Acute cellular rejection of the airways can be distinguished from infection pathologically and on cultures. Separating small from large airways need not be an issue because both are risk factors for bronchiolitis obliterans. Grading of airway rejection needs to be standardized. Chronic lung allograft dysfunction consists of both bronchiolitis obliterans and restrictive allograft syndrome, neither of which can be treated very effectively at present. PMID:26927718

  1. Comparison of analysis methods for airway quantification

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.

    2012-03-01

    Diseased airways have been known for several years as a possible contributing factor to airflow limitation in Chronic Obstructive Pulmonary Diseases (COPD). Quantification of disease severity through the evaluation of airway dimensions - wall thickness and lumen diameter - has gained increased attention, thanks to the availability of multi-slice computed tomography (CT). Novel approaches have focused on automated methods of measurement as a faster and more objective means that the visual assessment routinely employed in the clinic. Since the Full-Width Half-Maximum (FWHM) method of airway measurement was introduced two decades ago [1], several new techniques for quantifying airways have been detailed in the literature, but no approach has truly become a standard for such analysis. Our own research group has presented two alternative approaches for determining airway dimensions, one involving a minimum path and the other active contours [2, 3]. With an increasing number of techniques dedicated to the same goal, we decided to take a step back and analyze the differences of these methods. We consequently put to the test our two methods of analysis and the FWHM approach. We first measured a set of 5 airways from a phantom of known dimensions. Then we compared measurements from the three methods to those of two independent readers, performed on 35 airways in 5 patients. We elaborate on the differences of each approach and suggest conclusions on which could be defined as the best one.

  2. Breath tests and airway gas exchange.

    PubMed

    Anderson, Joseph C; Hlastala, Michael P

    2007-01-01

    Measuring soluble gas in the exhaled breath is a non-invasive technique used to estimate levels of respiratory, solvent, and metabolic gases. The interpretation of these measurements is based on the assumption that the measured gases exchange in the alveoli. While the respiratory gases have a low blood-solubility and exchange in the alveoli, high blood-soluble gases exchange in the airways. The effect of airway gas exchange on the interpretation of these exhaled breath measurements can be significant. We describe airway gas exchange in relation to exhaled measurements of soluble gases that exchange in the alveoli. The mechanisms of airway gas exchange are reviewed and criteria for determining if a gas exchanges in the airways are provided. The effects of diffusion, perfusion, temperature and breathing maneuver on airway gas exchange and on measurement of exhaled soluble gas are discussed. A method for estimating the impact of airway gas exchange on exhaled breath measurements is presented. We recommend that investigators should carefully control the inspired air conditions and type of exhalation maneuver used in a breath test. Additionally, care should be taken when interpreting breath tests from subjects with pulmonary disease. PMID:16413216

  3. Fast and Efficient non-reduced Lys-C digest using pressure cycling technology for antibody disulfide mapping by LC-MS.

    PubMed

    Cheng, Ying; Chen, Yonghong; Yu, Christopher

    2016-09-10

    Conventional sample preparation for antibody disulfide mapping often requires relatively long digestion time (from several hours to overnight) and relatively high endoproteinase concentration. These conditions are typically necessitated by the fact that antibody molecules are not sufficiently denatured under non-reduced conditions and chaotropic agents are used during digestion to achieve optimal denaturation. Disulfide scrambling can occur as artifacts of digestion as proteins are incubated for extended periods, often at neutral to slightly alkaline pH conditions. Shortening digestion time and lowering the pH during digestion frequently result in incomplete peptide cleavages or variable recoveries. Here, we report the development of a fast and efficient non-reduced Lys-C digestion method based on pressure cycling technology (PCT) and its application in determining disulfide-linkages in monoclonal antibodies (mAbs). Conditions were optimized to ensure complete digestion of the mAb with minimal sample preparati