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Airway Pressure (airway + pressure)

Distribution by Scientific Domains
Medical Sciences97%
Life Sciences2%
Distribution within Medical Sciences
Anesthesia & Pain Management27%
Cardiovascular Disease4%
Nursing General2%
17 Other Subdomains40%

Kinds of Airway Pressure

  • continuous positive airway pressure
  • mean airway pressure
    		•
  • nasal continuous positive airway pressure
  • peak airway pressure
    		•
  • positive airway pressure

    • Terms modified by Airway Pressure

  • airway pressure therapy
    		•
  • airway pressure ventilation
    		•

    Selected Abstracts

    Changes in dreaming induced by CPAP in severe obstructive sleep apnea syndrome patients

    JOURNAL OF SLEEP RESEARCH, Issue 4 2006
    EVA CARRASCO
    Summary To study dream content in patients with severe obstructive sleep apnea syndrome (OSAS) and its modification with Continuous Positive Airway Pressure (CPAP) therapy. We assessed twenty consecutive patients with severe OSAS and 17 healthy controls. Polysomnograms were recorded at baseline in patients and controls and during the CPAP titration night, 3 months after effective treatment and 2 years later in patients. Subjects were awakened 5,10 min after the beginning of the first and last rapid eye movement (REM) sleep periods and we measured percentage of dream recall, emotional content of the dream, word count, thematic units, sleep architecture and REM density. Dream recall in REM sleep was similar in patients at baseline and controls (51.5% versus 44.4% respectively; P = .421), decreased to 20% and 24.3% the first and third month CPAP nights, and increased to 39% 2 years later (P = 0.004). Violent/highly anxious dreams were only seen in patients at baseline. Word count was higher in patients than in controls. REM density was highest the first CPAP night. Severe OSAS patients recall dreams in REM sleep as often as controls, but their dreams have an increased emotional tone and are longer. Despite an increase in REM density, dream recall decreased the first months of CPAP and recovered 2 years later. Violent/highly anxious dreams disappeared with treatment. A dream recall decrease with CPAP is associated with normalization of sleep in OSAS patients. [source]

    A Comparison of the Long-Term Outcome and Effects of Surgery or Continuous Positive Airway Pressure on Patients with Obstructive Sleep Apnea Syndrome

    THE LARYNGOSCOPE, Issue 6 2006
    Shih-Wei Lin
    Abstract Objectives: To compare the long-term (3-year) outcome and effects of continuous positive airway pressure (CPAP) and extended uvulopalatoplasty (EUPF) treatment on patients with obstructive sleep apnea syndrome. Methods: Eighty-four patients who received CPAP titration and bought a CPAP machine to use from March 2000 to October 2001 were included as the CPAP group. Another 55 patients who underwent EUPF surgery were included as the EUPF group. Overnight polysomnography was performed 6 months and 3 years after CPAP titration or EUPF. The disease-specific questionnaire-Snore Outcome Survey (SOS), Epworth Sleepiness Scale (ESS), and the generic health questionnaire-MOSF-36 were administered at the 6-month and 3-year follow-up examinations. Results: The age, body mass index, respiratory disturbance index, and ESS before treatment were higher in the CPAP group. The snore index was higher in the surgery group. Fifty-four patients (64.3%) in CPAP group continued treatment for 6 months; the success rate for EUPF at 6 months was 82%. The polysomnographic variables improved significantly in both groups. Improvements in the SOS and ESS scores were better in surgery group than the CPAP group. The subscales of SF-36 in surgery group were more than those in CPAP group. Conclusions: EUPF had a better effect on snoring than CPAP 6 months after treatment in patients with obstructive sleep apnea syndrome (OSAS). This effect had gradually declined at the 3-year follow-up examination. Improvement in the quality of life of OSAS patients receiving EUPF is equal to those receiving CPAP treatment. [source]

    Pressure-rate product and phase angle as measures of acute inspiratory upper airway obstruction in rhesus monkeys

    PEDIATRIC PULMONOLOGY, Issue 7 2010
    FAAP, Patrick A. Ross MD
    Abstract Rationale There are limited validated, objective, and minimally invasive techniques for the bedside evaluation of upper airway obstruction (UAO) in sick infants, despite its frequency in pediatric medicine. Prior techniques include pressure-rate product (PRP), a product of esophageal pressure and respiratory rate and phase angles (PAs), a measure of asynchrony between ribcage and abdominal respiratory movements in infants with UAO. The purpose of this study is to validate the PRP and compare it to a previously validated PA in rhesus monkeys. Methods Calibrated resistors were applied to the inspiratory limb of 10 anesthetized, intubated, and spontaneously breathing rhesus monkeys (weight 8.7,±,2.5,kg). Airway pressure, respiratory rate, PAs, heart rate, and oxygen saturation were recorded. Obstruction was applied in random order as 0, 5, 20, 200, 500, and 1,000,cmH2O/L/sec for 2-min periods, the last 15,sec (10,20 breaths) were analyzed for each timeframe. Results PA increased significantly at the 200,cmH2O/L/sec level but it reached a plateau above 500,cmH2O/L/sec. PRP rose progressively and was significantly different at all levels of obstruction. Esophageal pressure change was progressively and statistically significantly different from baseline and each other at 200, 500, and 1,000,cmH2O/L/sec (P,<,0.001). Conclusions In this model of UAO, PRP tracks increasing inspiratory load better than PA. PRP continued to be linear up through the highest inspiratory resistance where the change in PA reached a plateau before the highest load. The assessment of esophageal pressure changes may offer the simplest objective measure of UAO. Pediatr Pulmonol. 2010; 45:639,644. © 2010 Wiley-Liss, Inc. [source]

    Budesonide delivered by dosimetric jet nebulization to preterm very low birthweight infants at high risk for development of chronic lung disease

    ACTA PAEDIATRICA, Issue 12 2000
    B Jónsson
    We investigated the effect of an aerosolized corticosteroid (budesonide) on the oxygen requirement of infants at high risk for developing chronic lung disease (CLD) in a randomized, double-blind study. The study objective was to attain a 30% decrease in FiO2 levels in the budesonide treatment group after 14 d of therapy. Thirty very low birthweight (VLBW) infants (median (range)) gestational age 26 wk (23,29) and birthweight 805 g (525,1227) were randomized. Inclusion criteria were mechanical ventilation on day 6 of life, or if extubated on nasal continuous positive airway pressure with FiO2± 0.3. The budesonide (PulmicortÔ dose was 500 ,g bid, or placebo. The aerosol was delivered with a dosimetric jet nebulizer, with variable inspiratory time and breath sensitivity. Inhalations were started on day 7 of life. Twenty-seven patients completed the study. A significant lowering of the FiO2 levels at 21 d of life was not detected. Infants who received budesonide were more often extubated during the study period (7/8 vs 2/9) and had a greater relative change from baseline in their oxygenation index (budesonide decreased 26% vs placebo increased 60%). Subsequent use of intravenous dexamethasone or inhaled budesonide in the treatment group was significantly less. All patients required O2 supplementation on day 28 of life. At 36 wk postconceptual age, 61% of infants in the budesonide group needed supplemental O2 as opposed to 79% in the placebo group. No side effects on growth or adrenal function were observed Conclusion: We conclude that inhaled budesonide aerosol via dosimetric jet nebulizer started on day 7 of life for infants at high risk for developing CLD decreases the need for mechanical ventilation similar to intravenous dexamethasone, but without significant side effects. [source]

    Randomized trial comparing natural and synthetic surfactant: increased infection rate after natural surfactant?

    ACTA PAEDIATRICA, Issue 5 2000
    AK Kukkonen
    The efficacy of a natural porcine surfactant and a synthetic surfactant were compared in a randomized trial. In three neonatal intensive care units, 228 neonates with respiratory distress and a ratio of arterial to alveolar partial pressure of oxygen <0.22 were randomly assigned to receive either Curosurf 100mgkg,1 or Exosurf Neonatal 5 ml kg,1. After Curosurf, the fraction of inspired oxygen was lower from 15min (0.45 ± 0.22 vs 0.70 ± 0.22, p = 0.0001) to 6 h (0.48 ± 0.26 vs 0.64 ± 0.23,p= 0.0001) and the mean airway pressure was lower at 1 h (8.3 3.2 mmH2O vs 9.4 ± 3.1 mmH2O ,= 0.01). Thereafter the respiratory parameters were similar. The duration of mechanical ventilation (median 6 vs 5 d) and the duration of oxygen supplementation (median 5 vs 4 d) were similar for Curosurf and Exosurf After Curosurf, C-reactive protein value over 40 mg r1 occurred in 45% (vs 12%; RR 3.62, 95%CI 2.12-6.17, p = 0.001), leukopenia in 52% (vs 28%; RR 1.85, 95%CI 1.31-2.61, ,= 0.001) and bacteraemia in 11% (vs 4%; RR3.17, 95%CI 1.05-9.52, p < 0.05). We conclude that when given as rescue therapy Curosurf had no advantage compared with Exosurf in addition to the more effective initial response. Curosurf may increase the risk of infection. [source]

    Cardiogenic Unilateral Pulmonary Edema: An Unreported Complication of a Digestive Endoscopic Procedure

    CONGESTIVE HEART FAILURE, Issue 5 2009
    Enrique M. Baldessari MD
    Unilateral pulmonary edema is an uncommon clinical situation that may be difficult to distinguish from other conditions that cause lung infiltrates. Most cases occur in the right lung, and there are no reports about cardiogenic unilateral pulmonary edema as a complication of an endoscopic procedure of gastrointestinal tract. The authors describe a case of a 79-year-old woman with acute cardiac heart failure that developed soon after a diagnostic upper and lower digestive endoscopy. Continuous positive airway pressure, intravenous nitroglycerin, and furosemide treatment resulted in rapid improvement of symptoms and the progressive resolution of left-sided infiltrates on chest radiography. This case is of particular importance because of the rarity of cardiogenic unilateral edema in the left lung. This clinical finding was associated with the prolonged rest on the left side during the gastrointestinal endoscopic procedure. [source]

    Prevalence of Sleep Disordered Breathing in a Heart Failure Program

    CONGESTIVE HEART FAILURE, Issue 5 2004
    Robin J. Trupp MSN
    Recent data show that a high percentage of patients with systolic left ventricular dysfunction have sleep-disordered breathing (SDB), contributing to the incidence of morbidity and mortality in heart failure. This study examines the prevalence of sleep disorders in stable heart failure patients regardless of ejection fraction. On three consecutive days in a heart failure clinic, all patients were asked to participate in a screening for SDB. This screening involved the placement of an outpatient device (ClearPath, Nexan, Inc., Alpharetta, GA), which collects thoracic impedance, oxyhemoglobin saturation, and 2-lead electrocardiogram data. Sixteen patients (42%) had moderate or severe SDB, and 22 patients (55%) had mild or no significant SDB. Fourteen of the 16 patients with moderate or severe SDB subsequently received treatment by confirming SDB and the continuous positive airway pressure in a sleep lab. Forty-two percent of patients with stable heart failure presenting to a heart failure clinic screened positive for SDB, despite receiving optimal standard of care. [source]

    5-Hydroxytryptamine-induced microvascular pressure transients in lungs of anaesthetized rabbits

    ACTA PHYSIOLOGICA, Issue 2 2001
    N. Sen
    We determined lung microvascular pressure transients induced by 5-hydroxytryptamine (5HT), by the micropuncture technique. We mechanically ventilated anaesthetized (halothane 0.8%), open-chested rabbits, in which we recorded pulmonary artery (PA), left atrial (LA) and carotid artery pressures and cardiac output. For 4-min periods of stopped ventilation, we constantly inflated the lung with airway pressure of 7 cmH2O, then micropunctured the lung to determine pressures in arterioles and venules of 20,25 ,m diameter. An intravenous bolus infusion of 5HT (100 ,g), increased total pulmonary vascular resistance by 59%. Prior to 5HT infusion, the arterial, microvascular and venous segments comprised 30, 50 and 19% of the total pulmonary vascular pressure drop, respectively. However 14 s after 5HT infusion, the PA-arteriole pressure difference (arterial pressure drop) increased 46%, while the venule-LA pressure difference (venous pressure drop) increased >100%. The arteriole,venule pressure difference (microvascular pressure drop) was abolished. The increase in the arterial pressure drop was maintained for 4.8 min, whereas the increased venous pressure drop reverted to baseline in <1 min. We conclude that in the rabbit lung in situ, a 5HT bolus causes sustained arterial constriction and a strong but transient venous constriction. [source]

    Effects of Continuous Positive Airway Pressure Therapy on Right Ventricular Function Assessment by Tissue Doppler Imaging in Patients with Obstructive Sleep Apnea Syndrome

    ECHOCARDIOGRAPHY, Issue 10 2008
    Nihal Akar Bayram M.D.
    Objectives: The effects of continuous positive airway pressure (CPAP) therapy on right ventricular (RV) function in patients with obstructive sleep apnea syndrome (OSAS) has not been previously studied by tissue Doppler imaging (TDI). The aim of this study was to assess RV function using TDI in patients with OSAS before and after CPAP therapy. Methods: Twenty-eight patients with newly diagnosed OSAS in the absence of any confounding factors and 18 controls were included in this study. The peak systolic velocity (S,m), early (E,m) and late (A,m) diastolic myocardial peak velocities at tricuspid lateral annulus, isovolumic acceleration (IVA), myocardial precontraction time (PCT,m), myocardial contraction time (CT,m), and myocardial relaxation time (RT,m) were measured. All echocardiographic parameters were calculated 6 months after CPAP therapy. Results: The RV diastolic parameters such as E,m velocity and E,m-to-A,m ratio were significantly lower, RT,m was significantly prolonged, A,m velocity was similar in patients with OSAS compared to controls; and the RV systolic parameters such as IVA and CT,m were significantly lower and S,m was similar in patients with OSAS compared to controls. At the end of the treatment, 20 of 28 patients were compliant with CPAP therapy. E,m velocity, E,m-to-A,m ratio, IVA, and CT,m increased, PCT,m, PCT,m-to-CT,m ratio, and RT,m decreased significantly after therapy, whereas S,m velocity and A,m velocity did not change after CPAP treatment in the compliant patients. Conclusion: OSAS is associated with RV systolic and diastolic dysfunction, and 6 months of CPAP therapy improves the RV systolic and diastolic dysfunction. [source]

    Effects of unilateral laser-assisted ventriculocordectomy in horses with laryngeal hemiplegia

    EQUINE VETERINARY JOURNAL, Issue 6 2006
    P. ROBINSON
    Summary Reasons for performing study: Recent studies have evaluated surgical techniques aimed at reducing noise and improving airway function in horses with recurrent laryngeal neuropathy (RLN). These techniques require general anaesthesia and are invasive. A minimally invasive transnasal surgical technique for treatment of RLN that may be employed in the standing, sedated horse would be advantageous. Objective: To determine whether unilateral laser-assisted ventriculocordectomy (LVC) improves upper airway function and reduces noise during inhalation in exercising horses with laryngeal hemiplegia (LH). Methods: Six Standardbred horses were used; respiratory sound and inspiratory transupper airway pressure (Pui) measured before and after induction of LH, and 60, 90 and 120 days after LVC. Inspiratory sound level (SL) and the sound intensities of formants 1, 2 and 3 (F1, F2 and F3, respectively), were measured using computer-based sound analysis programmes. In addition, upper airway endoscopy was performed at each time interval, at rest and during treadmill exercise. Results: In LH-affected horses, Pui, SL and the sound intensity of F2 and F3 were increased significantly from baseline values. At 60 days after LVC, Pui and SL had returned to baseline, and F2 and F3 values had improved partially compared to LH values. At 90 and 120 days, however, SL increased again to LH levels. Conclusions: LVC decreases LH-associated airway obstruction by 60 days after surgery, and reduces inspiratory noise but not as effectively as bilateral ventriculocordectomy. Potential relevance: LVC may be recommended as a treatment of LH, where reduction of upper airway obstruction and respiratory noise is desired and the owner wishes to avoid risks associated with a laryngotomy incision or general anaesthesia. [source]

    Effects of stylopharyngeus muscle dysfunction on the nasopharynx in exercising horses

    EQUINE VETERINARY JOURNAL, Issue 4 2004
    C. TESSIER
    Summary Reasons for performing study: Nasopharyngeal collapse has been observed in horses as a potential cause of exercise intolerance and upper respiratory noise. No treatment is currently available and affected horses are often retired from performance. Objective: To determine the effect of bilateral glossopharyngeal nerve block and stylopharyngeus muscle dysfunction on nasopharyngeal function and airway pressures in exercising horses. Methods: Endoscopic examinations were performed on horses at rest and while running on a treadmill at speeds corresponding to HRmax50, HRmax75 and HRmax, with upper airway pressures measured with and without bilateral glossopharyngeal nerve block. Results: Bilateral glossopharyngeal nerve block caused stylopharyngeus muscle dysfunction and dorsal nasopharyngeal collapse in all horses. Peak inspiratory upper airway pressure was significantly (P = 0.0069) more negative at all speeds and respiratory frequency was lower (P = 0.017) in horses with bilateral glossopharyngeal nerve block and stylopharyngeus muscle dysfunction compared to control values. Conclusions: Bilateral glossopharyngeal nerve anaesthesia produced stylopharyngeus muscle dysfunction, dorsal pharyngeal collapse and airway obstruction in all horses. Potential relevance: The stylopharyngeus muscle is probably an important nasopharyngeal dilating muscle in horses and dysfunction of this muscle may be implicated in clinical cases of dorsal nasopharyngeal collapse. Before this information can be clinically useful, further research on the possible aetiology of stylopharyngeus dysfunction and dysfunction of other muscles that dilate the dorsal and lateral walls of the nasopharynx in horses is needed. [source]

    Effects of Lung Volume on Parasternal Pressure-Generating Capacity in Dogs

    EXPERIMENTAL PHYSIOLOGY, Issue 3 2000
    Anthony F. DiMarco
    Previous studies have suggested that the optimum length for force generation of the parasternal intercostal (PS) muscles is well above functional residual capacity (FRC). We further explored this issue by examining the pressure-generating capacity of the PS muscles as a function of lung volume in anaesthetized dogs. Upper thoracic spinal cord stimulation (SCS) was used to electrically activate the PS muscles. Changes in airway pressure and parasternal resting length (LR) during airway occlusion were monitored over a wide range of lung volumes during SCS. To assess the effects of parasternal contraction alone, SCS was performed following phrenicotomy and section of the external intercostal, levator costae and triangularis sterni muscles. With increasing lung volume, there were progressive decrements in the capacity of the PS muscles to produce changes in airway pressure. The relationship between PS pressure generation and lung volume was similar to a previous comparable assessment of the external intercostal muscles. The PS muscles shortened during passive inflation and also shortened further (by > 20% of LR) during SCS. Total shortening (passive plus active) increased progressively with increasing lung volume. Our results indicate that the capacity of the PS muscles to produce changes in airway pressure (a) falls progressively with increasing lung volume and (b) is similar to that of the external intercostal muscles. We speculate that the fall in PS pressure-generating capacity is related, in part, to progressive reductions in end-inspiratory length. [source]

    The effects of methylene blue on ovine post-pneumonectomy pulmonary oedema

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2010
    E. V. SUBOROV
    Background: We recently reported that post-pneumonectomy pulmonary oedema (PPO) occurs after ventilating the remaining lung with excessive tidal volumes. Studies in small animals have indicated that nitric oxide (NO) release increases in hyper-inflated lungs, but confirmatory evidence from larger animals is still lacking. We hypothesized that PPO could be prevented by methylene blue (MB), an inhibitor of NO synthase. Methods: Sheep were subjected to a right-sided pneumonectomy (PE) and randomly assigned to a protectively ventilated group ((PROTV group, n=7) with tidal volumes of 6 ml/kg at 20 inflations/min and a positive end-expiratory pressure (PEEP) of 2 cmH2O, and two groups undergoing ,injurious ventilation' (INJV) with tidal volumes of 12 ml/kg and zero end-expiratory pressure (ZEEP), a control group (INJV group, n=7) and a treatment group subjected to MB 1 h after PE (INJV+MB group, n=7). Haemodynamic variables, lung mechanics, blood gases and plasma nitrites and nitrates (NOx) were determined. Results: PE reduced pulmonary blood volume, extravascular lung water (EVLWI) and quasistatic lung compliance in all groups, in parallel with a rise in peak airway pressure (P<0.05). In the INJV group, pulmonary arterial pressure, EVLWI and pulmonary vascular permeability index increased and arterial oxygenation decreased towards cessation of the experiments. These changes were not antagonized by MB. Plasma NOx increased in all the groups compared with baseline, but with no intergroup difference. Conclusion: MB did not reduce PPO and accumulation of NOx in sheep subjected to ventilation with excessive tidal volumes and ZEEP. [source]

    Larger tidal volume increases sevoflurane uptake in blood: a randomized clinical study

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2010
    B. ENEKVIST
    Background: The rate of uptake of volatile anesthetics is dependent on alveolar concentration and ventilation, blood solubility and cardiac output. We wanted to determine whether increased tidal volume (VT), with unchanged end-tidal carbon dioxide partial pressure (PETCO2), could affect the arterial concentration of sevoflurane. Methods: Prospective, randomized, clinical study. ASA physical status 2 and II patients scheduled for elective surgery of the lower abdomen were randomly assigned to one of the two groups with 10 patients in each: one group with normal VT (NVT) and one group with increased VT (IVT) achieved by increasing the inspired plateau pressure 0.04 cmH2O/kg above the initial plateau pressure. A corrugated tube added extra apparatus dead space to maintain PETCO2 at 4.5 kPa. The respiratory rate was set at 15 min,1, and sevoflurane was delivered to the fresh gas by a vaporizer set at 3%. Arterial sevoflurane tensions (Pasevo), Fisevo, PETsevo, PETCO2, PaCO2, VT and airway pressure were measured. Results: The two groups of patients were similar with regard to gender, age, weight, height and body mass index. The mean PETsevo did not differ between the groups. Throughout the observation time, arterial sevoflurane tension (mean±SE) was significantly higher in the IVT group compared with the NVT group, e.g. 1.9±0.23 vs. 1.6±0.25 kPa after 60 min of anesthesia (P<0.05). Conclusion: Ventilation with larger tidal volumes with isocapnia maintained with added dead-space volume increases the tension of sevoflurane in arterial blood. [source]

    Exposure to anaesthetic trace gases during general anaesthesia: CobraPLA vs.

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2010
    LMA classic
    Background: To prospectively investigate the performance, sealing capacity and operating room (OR) staff exposure to waste anaesthetic gases during the use of the Cobra perilaryngeal airway (CobraPLA) compared with the laryngeal mask airway classic (LMA). Methods: Sixty patients were randomly assigned to the CobraPLA or the LMA group. Insertion time, number of insertion attempts and airway leak pressures were assessed after induction of anaesthesia. Occupational exposure to nitrous oxide (N2O) and Sevoflurane (SEV) was measured at the anaesthetists' breathing zone and the patients' mouth using a photoacoustic infrared spectrometer. Results: N2O waste gas concentrations differed significantly in the anaesthetist's breathing zone (11.7±7.2 p.p.m. in CobraPLA vs. 4.1±4.3 p.p.m. in LMA, P=0.03), whereas no difference could be shown in SEV concentrations. Correct CobraPLA positioning was possible in 28 out of 30 patients (more than one attempt necessary in five patients). Correct positioning of the LMA classic was possible in all 30 patients (more than one attempt in three patients). Peak airway pressure was higher in the CobraPLA group (16±3 vs. 14±2 cmH2O, P=0.01). The average leak pressure of the CobraPLA was 24±4 cmH2O, compared with 20±4 cmH2O of the LMA classic (P<0.001; all values means±SD). Conclusion: Despite higher airway seal pressures, the CobraPLA caused higher intraoperative N2O trace concentrations in the anaesthetists' breathing zone. [source]

    Chest physiotherapy with positive expiratory pressure breathing after abdominal and thoracic surgery: a systematic review

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2010
    J. ÖRMAN
    A variety of chest physiotherapy techniques are used following abdominal and thoracic surgery to prevent or reduce post-operative complications. Breathing techniques with a positive expiratory pressure (PEP) are used to increase airway pressure and improve pulmonary function. No systematic review of the effects of PEP in surgery patients has been performed previously. The purpose of this systematic review was to determine the effect of PEP breathing after an open upper abdominal or thoracic surgery. A literature search of randomised-controlled trials (RCT) was performed in five databases. The trials included were systematically reviewed by two independent observers and critically assessed for methodological quality. We selected six RCT evaluating the PEP technique performed with a mechanical device in spontaneously breathing adult patients after abdominal or thoracic surgery via thoracotomy. The methodological quality score varied between 4 and 6 on the Physiotherapy Evidence Database score. The studies were published between 1979 and 1993. Only one of the included trials showed any positive effects of PEP compared to other breathing techniques. Today, there is scarce scientific evidence that PEP treatment is better than other physiotherapy breathing techniques in patients undergoing abdominal or thoracic surgery. There is a lack of studies investigating the effect of PEP over placebo or no physiotherapy treatment. [source]

    Effects of surfactant replacement on alveolar overdistension and plasma cytokines in ventilator-induced lung injury

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2010
    H. WU
    Background: Overdistension of the lung causes ventilator-induced lung injury (VILI) accompanied by surfactant abnormalities and inflammatory changes. We investigated the effects of surfactant replacement on overdistension of the terminal airspaces and plasma cytokine levels in VILI. Methods: VILI was induced by high-pressure ventilation (HPV) in rats anesthetized with pentobarbital, followed by ventilation for 2 h in the maintenance mode (tidal volume=10 ml/kg, positive end-expiratory pressure=7.5 cmH2O) with or without surfactant replacement. The sizes of the terminal airspaces were determined after fixing the lungs at an airway pressure of 10 cmH2O on deflation. Cytokine levels were assessed by enzyme-linked immunosorbent assay. Results: The mean ratio of the largest terminal airspace size class (,64,000 ,m2) was increased from 13.4% to 32.0% by HPV (P<0.05). After maintenance-mode ventilation, the ratio decreased to 16.1% with surfactant replacement (P<0.05), but increased to 44.6% without surfactant replacement (P<0.05). Mean macrophage inflammatory protein-2 (MIP-2) levels in the plasma increased from <0.02 to 6.9 ng/ml with HPV (P<0.05), and further increased to ,11.8 ng/ml, regardless of surfactant replacement after maintenance-mode ventilation. Similar tendencies were observed in the interleukin (IL)-6 and IL-10 levels. Tumor necrosis factor-, levels were almost negligible during the experiment. Conclusion: In rats with VILI, surfactant replacement reversed overdistension of the terminal airspaces that may induce barotrauma, but not upregulation of MIP-2, IL-6, and IL-10 within 2 h. [source]

    Chronic Obstructive Pulmonary Disease Diagnosis and Management in Older Adults

    JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2010
    Nalaka S. Gooneratne MD
    Chronic obstructive pulmonary disease (COPD) in older adults is a complex disorder with several unique age-related aspects. Underlying changes in pulmonary lung function and poor sensitivity to bronchoconstriction and hypoxia with advancing age can place older adults at greater risk of mortality or other complications from COPD. The establishment of the Global Initiative for Obstructive Lung Disease criteria, which can be effectively applied to older adults, has more rigorously defined the diagnosis and management of COPD. An important component of this approach is the use of spirometry for disease staging, a procedure that can be performed in most older adults. The management of COPD includes smoking cessation, influenza and pneumococcal vaccinations, and the use of short- and long-acting bronchodilators. Unlike with asthma, corticosteroid inhalers represent a third-line option for COPD. Combination therapy is frequently required. When using various inhaler designs, it is important to note that older adults, especially those with more-severe disease, may have inadequate inspiratory force for some dry-powder inhalers, although many older adults find the dry-powder inhalers easier to use than metered-dose inhalers. Other important treatment options include pulmonary rehabilitation, oxygen therapy, noninvasive positive airway pressure, and depression and osteopenia screening. Clinicians caring for older adults with an acute COPD exacerbation should also guard against prognostic pessimism. Although COPD is associated with significant disability, there is a growing range of treatment options to assist patients. [source]

    PEEP Therapy for Patients With Pleurotomy During Coronary Artery Bypass Grafting

    JOURNAL OF CARDIAC SURGERY, Issue 3 2000
    Susumu Ishikawa M.D.
    We studied the efficacy of intraoperative positive end-expiratory airway pressure (PEEP) therapy for the prevention of postoperative pulmonary oxygenation impairment. A total of 66 patients with solitary CABG procedure were included in this study. The pleural cavity was intraoperatively opened in 44 patients and not opened in 22. PEEP therapy was not used in any patient before May 1996 (referred to herein as the former period) and was used more recently in eight patients with pleurotomy (referred to herein as the latter period). PEEP was initiated immediately after pleurotomy during the harvest of the internal mammary artery graft. Without PEEP therapy, values of PaO2, A-aDO2, and respiratory index (RI) were worse in patients with pleurotomy than in those without pleurotomy. Meanwhile, there were no major differences in these values between patients with or without pleurotomy after the induction of PEEP therapy. Respiratory insufficiency (A-aDO2 > 400 mmHg and RI > 1.5) was detected in six patients with pleurotomy in the former period. Three of these six patients required over 1 week of long-term mechanical respiratory support. No respiratory insufficiency occurred in patients of the latter period. In conclusion, PEEP therapy, which is initiated just after pleurotomy, may prevent oxygen impairment and pulmonary atelectasis after extracorporeal circulation (ECC) and is recommended for patients with pleurotomy, especially for patients with preoperative low respiratory function. [source]

    Review of non-invasive ventilation in the emergency department: clinical considerations and management priorities

    JOURNAL OF CLINICAL NURSING, Issue 23 2009
    Louise Rose
    Aims and objectives., We aimed to synthesise evidence from published literature on non-invasive ventilation to inform nurses involved in the clinical management of non-invasive ventilation in the emergency department. Background., Non-invasive ventilation is a form of ventilatory support that does not require endotracheal intubation and is used in the early management of acute respiratory failure in emergency departments. Safe delivery of this intervention requires a skilled team, educated and experienced in appropriate patient selection, available devices and monitoring priorities. Design., Systematic review. Method., A multi-database search was performed to identify works published in the English language between 1998,2008. Search terms included: non-invasive ventilation, continuous positive airway pressure and emergency department. Inclusion and exclusion criteria for the review were identified and systematically applied. Results., Terminology used to describe aspects of non-invasive ventilation is ambiguous. Two international guidelines inform the delivery of this intervention, however, much research has been undertaken since these publications. Strong evidence exists for non-invasive ventilation for patients with acute exacerbation of congestive heart failure and chronic obstructive pulmonary disease. Non-invasive ventilation may be delivered with various interfaces and modes; little evidence is available for the superiority of individual interfaces or modes. Conclusions., Early use of non-invasive ventilation for the management of acute respiratory failure may reduce mortality and morbidity. Though international guidelines exist, specific recommendations to guide the selection of modes, settings or interfaces for various aetiologies are lacking due to the absence of empirical evidence. Relevance to clinical practice., Monitoring of non-invasive ventilation should focus on assessment of response to treatment, respiratory and haemodynamic stability, patient comfort and presence of air leaks. Complications are related to mask-fit and high air flows; serious complications are few and occur infrequently. The use of non-invasive ventilation has resource implications that must be considered to provide effective and safe management in the emergency department. [source]

    Protein intake, growth and lung function of infants with chronic lung disease

    JOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 3 2009
    E. Cillié
    Background:, The increased survival rate of extremely preterm infants has not improved the incidence or outcome of infants diagnosed with chronic lung disease (CLD) (Riley, 2008). The relationship between optimal nutrition (particularly protein intake) and chronic lung disease has not been established. The aim of this study was to investigate the association between protein intake, growth and lung function in infants with CLD. Methods:, A CLD database, maintained for the past 10 years, was used to select participants that had reached 1 year of corrected age. Infants who were born during 2001,2006 with a birth weight of <1500 g, and who subsequently had a diagnosis of CLD, were included. Infants with evidence of intra-uterine growth restriction and abnormal cerebral pathology were excluded. Demographic, mean weight gain, protein intake and respiratory support data were collected retrospectively from the medical notes. Growth parameters and need for oxygen and inhalers up to 1 year of corrected age were collected from the CLD follow-up database. SPSS, version 15 (SPSS Inc., Chicago, IL, USA) were used for Pearson's or Spearmans correlation analysis and analysis of variance or the Wilcoxon test, as appropriate. Results:, Sixty infants were studied: 25 females and 35 males. The median (range) post-menstrual age at birth was 26 (22,31) weeks. The most common feed was breast milk; fortified breast milk was used for 37% of the total days studied. The mean (SD) protein intake was 2.28 (0.33) g kg,1 day,1 and the mean (SD) weight gain was 11.67 (1.77) g kg,1 day,1. There was a positive correlation between protein intake and weight gain (r = 0.32, P = 0.013), which was stronger in females (r = 0.51, P = 0.009). Protein intake was significantly associated with head circumference growth in females only (r = 0.47, P = 0.038). Protein intake was inversely related to the number of days spent mechanically ventilated (r = ,0.32, P = 0.015). There was no relationship between protein intake and growth at 1 year corrected age, time spent on continuous positive airway pressure, age weaned off oxygen, or the use of inhalers. There was an inverse correlation between total weeks of oxygen dependence and head circumference at 1 year (r = ,0.35, P = 0.022). Discussion:, The mean protein intake was <3 g kg,1 day,1, which is the minimum requirement for preterm infants (Tsang et al., 2005). This was associated with a sub-optimal weight gain in our participants of <15 g kg,1 day,1 (Steward & Pridham, 2002). The study demonstrates the known association between low protein intake and poor growth with ventilator dependence (Loui et al., 2008). Conclusions:, Low birth weight and low gestational age infants at risk of CLD should receive special attention to optimise their protein intake because sub-optimal protein intake potentially leads to poor growth when on a neonatal intensive care unit. References Loui, A., Tsalikaki, E., Maier, K., Walch, E., Kamarianakis, Y. & Obladen, M. (2008) Growth in high risk infants <1500 g birth weight during the first 5 weeks. Early Hum. Dev. 84, 645,650, Doi: 10.1016/j.earlhumdev.2008.04.005. Riley, K., Roth, S., Sellwood, M. & Wyatt, J.S. (2008) Survival and neurodevelopmental morbidity at 1 year of age following extremely preterm delivery over a 20-year period: a single centre cohort study. Acta Paediatr.97, 159,165. Steward, D.K. & Pridham, K.F. (2002) Growth patterns of extremely low-birth-weight hospitalised preterm infants. JOGN Nurs31, 57,65. Tsang, R.C., Uauy, R., Koletzko, B. & Zlotkin, S.H., eds. (2005) Nutrition of the Preterm Infant: Scientific Basis and Practical Guidelines. Cincinnati: Digital Educational Publishing. [source]

    Beneficial effects of high positive end-expiratory pressure in lung respiratory mechanics during laparoscopic surgery

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2009
    L. F. MARACAJÁ-NETO
    Background: The effect of neuromuscular blockade (NMB) and positive end-expiratory pressure (PEEP) on the elastic properties of the respiratory system during pneumoperitoneum (PnP) remains a controversial subject. The main objective of the present study was to evaluate the effects of NMB and PEEP on respiratory mechanics. Methods: We performed a dynamic analysis of respiratory mechanics in patients subjected to PnP. Twenty-one patients underwent cholecystectomy videolaparoscopy and total intravenous anesthesia. The respiratory system resistance (RRS), pulmonary elastance (EP), chest wall elastance (ECW), and respiratory system elastance (ERS) were computed via the least squares fit technique using an equation describing the motion of the respiratory system, which uses primary signs such as airway pressure, tidal volume, air flow, and esophageal pressures. Measurements were taken after tracheal intubation, PnP, NMB, establishment of PEEP (10 cmH2O), and PEEP withdrawal [zero end-expiratory pressure (ZEEP)]. Results: PnP significantly increased ERS by 27%; both EP and ECW increased 21.3 and 64.1%, respectively (P<0.001). NMB did not alter the respiratory mechanic properties. Setting PEEP reduced ERS by 8.6% (P<0.05), with a reduction of 10.9% in EP (P<0.01) and a significant decline of 15.7% in RRS (P<0.05). These transitory changes in elastance disappeared after ZEEP. Conclusions: We concluded that the 10 cmH2O of PEEP attenuates the effects of PnP in respiratory mechanics, lowering RRS, EP, and ERS. These effects may be useful in the ventilatory approach for patients experiencing a non-physiological increase in IAP owing to PnP in laparoscopic procedures. [source]

    Short-term effects of a mandibular advancement device on obstructive sleep apnoea: an open-label pilot trial

    JOURNAL OF ORAL REHABILITATION, Issue 8 2005
    G. AARAB
    summary, Obstructive sleep apnoea (OSA) is a common sleep disorder, which is, among others, associated with snoring. OSA has a considerable impact on a patient's general health and daily life. Nasal continuous positive airway pressure (nCPAP) is frequently used as a ,gold standard' treatment for OSA. As an alternative, especially for mild/moderate cases, mandibular advancement devices (MADs) are prescribed increasingly. Their efficacy and effectiveness seem to be acceptable. Although some randomized clinical trials (RCTs) have been published recently, most studies so far are case studies. Therefore, our department is planning a controlled RCT, in which MADs are compared with both nCPAP and a control condition in a parallel design. As a first step, an adjustable MAD was developed with a small, more or less constant vertical dimension at different mandibular positions. To test the device and the experimental procedures, a pilot trial was performed with 10 OSA patients (six mild, four moderate; one women, nine men; mean age = 47·9 ± 9·7 years). They all underwent a polysomnographic recording before as well as 2,14 weeks after insertion of the MAD (adjusted at 50% of the maximal protrusion). The apnoea,hypopnoea index (AHI) was significantly reduced with the MAD in situ (P = 0·017). When analysed as separate groups, the moderate cases showed a significantly larger decrease in AHI than the mild cases (P = 0·012). It was therefore concluded from this pilot study that this MAD might be an effective tool in the treatment of, especially, moderate OSA. [source]

    Effects of PEEP levels following repeated recruitment maneuvers on ventilator-induced lung injury

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2008
    S.-C. KO
    Background: Different levels of positive end-expiratory pressure (PEEP) with and without a recruitment maneuver (RM) may have a significant impact on ventilator-induced lung injury but this issue has not been well addressed. Methods: Anesthetized rats received hydrochloric acid (HCl, pH 1.5) aspiration, followed by mechanical ventilation with a tidal volume of 6 ml/kg. The animals were randomized into four groups of 10 each: (1) high PEEP at 6 cm H2O with an RM by applying peak airway pressure at 30 cm H2O for 10 s every 15 min; (2) low PEEP at 2 cm H2O with RM; (3) high PEEP alone; and (4) low PEEP alone. Results: The mean arterial pressure and the amounts of fluid infused were similar in the four groups. Application of the higher PEEP improved oxygenation compared with the lower PEEP groups (P<0.05). The lung compliance was better reserved, and the systemic cytokine responses and lung wet to dry ratio were lower in the high PEEP than in the low PEEP group for a given RM (P<0.05). Conclusions: The use of a combination of periodic RM and the higher PEEP had an additive effect in improving oxygenation and pulmonary mechanics and attenuation of inflammation. [source]

    Exposure to noise during continuous positive airway pressure: influence of interfaces and delivery systems

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2008
    F. CAVALIERE
    Background: We measured noise intensity and perceived noisiness during continuous positive airway pressure (CPAP) performed with two interfaces (face-mask, helmet) and four delivery systems. Methods: Eight healthy volunteers received CPAP in random order with: two systems provided with a flow generator using the Venturi effect and a mechanical expiratory valve (A: Venturi, Starmed; B: Whisperflow-2, Caradyne Ltd); one ,free-flow' system provided with high flow O2 and air flowmeters, an inspiratory gas reservoir, and a water valve (C: CF800, Drägerwerk, AG); and a standard mechanical ventilator (Servoventilator 300, Siemens-Elema). Systems A, B, and C were tested with a face-mask and a helmet at a CPAP value of 10 cm H2O; the mechanical ventilator was only tested with the face mask. Noise intensity was measured with a sound-level meter. After each test, participants scored noisiness on a visual analog scale (VAS). Results: The noise levels measured ranged from 57±11 dBA (mechanical ventilator plus mask) to 93±1 and 94±2 dBA (systems A and B plus helmet) and were significantly affected by CPAP systems (A and B noisier than C and D) and interfaces (helmet CPAP noisier than mask CPAP). Subjective evaluation showed that systems A and B plus helmet were perceived as noisier than system C plus mask or helmet. Conclusions: Maximum noise levels observed in this study may potentially cause patient discomfort. Less noisy CPAP systems (not using Venturi effect) and interfaces (facial mask better than helmet) should be preferred, particularly for long or nocturnal treatments. [source]

    Continuous positive airway pressure treatment for obstructive sleep apnoea reduces resting heart rate but does not affect dysrhythmias: a randomised controlled trial

    JOURNAL OF SLEEP RESEARCH, Issue 3 2009
    SONYA CRAIG
    Summary Obstructive sleep apnoea (OSA) is associated with cardiovascular morbidity and may precipitate cardiac dysrhythmias. Uncontrolled reports suggest that continuous positive airway pressure (CPAP) may reduce dysrhythmia frequency and resting heart rate. We undertook a randomised controlled trial of therapeutic CPAP and compared with a subtherapeutic control which included an exploration of changes in dysrhythmia frequency and heart rate. Values are expressed as mean (SD). Eighty-three men [49.5 (9.6) years] with moderate,severe OSA [Oxygen Desaturation Index, 41.2 (24.3) dips per hour] underwent 3-channel 24-h electrocardiograms during normal daily activities, before and after 1 month of therapeutic (n = 43) or subtherapeutic (n = 40) CPAP. Recordings were manually analysed for mean heart rate, pauses, bradycardias, supraventricular and ventricular dysrhythmias. The two groups were well matched for age, body mass index, OSA severity, cardiovascular risk factors and history. Supraventricular ectopics and ventricular ectopics were frequently found in 95.2% and 85.5% of patients, respectively. Less common were sinus pauses (42.2%), episodes of bradycardia (12%) and ventricular tachycardias (4.8%). Compared with subtherapeutic control, CPAP reduced mean 24-h heart rate from 83.0 (11.5) to 79.7 (9.8) (P < 0.002) in the CPAP group compared with a non-significant rise (P = 0.18) from 79.0 (10.4) to 79.9 (10.4) in the subtherapeutic group; this was also the case for the day period analysed separately. There was no significant change in the frequencies of dysrhythmias after CPAP. Four weeks of CPAP therapy reduces mean 24-h heart rate possibly due to reduced sympathetic activation but did not result in a significant decrease in dysrhythmia frequency. [source]

    Daytime sympathetic hyperactivity in OSAS is related to excessive daytime sleepiness

    JOURNAL OF SLEEP RESEARCH, Issue 3 2007
    VINCENZO DONADIO
    Summary The aim of this study was to investigate the relationships among sympathetic hyperactivity, excessive daytime sleepiness (EDS) and hypertension in obstructive sleep apnoea syndrome (OSAS). Ten newly diagnosed OSAS patients with untreated EDS and daytime hypertension underwent polysomnography (PSG) and daytime measurements of plasma noradrenaline (NA), ambulatory blood pressure (BP), muscle sympathetic nerve activity (MSNA) by microneurography and objective assessment of EDS before and during 6 months of compliance-monitored continuous positive airway pressure (CPAP) treatment. One month after the start of CPAP, BP, MSNA and NA were significantly lowered, remaining lower than baseline also after 3 and 6 months of treatment. CPAP use caused a significant improvement of sleep structures, and reduced EDS. A statistical correlation analysis demonstrated that EDS was not correlated with sleep measures obtained from baseline PSG (% sleep stages, apnoea and arousal index, mean oxygen saturation value), whereas daytime sleepiness was significantly correlated with MSNA. Furthermore, MSNA and BP showed no correlation. Our data obtained from selected patients suggest that the mechanisms inducing EDS in OSAS are related to the degree of daytime sympathetic hyperactivity. Additionally, resting MSNA was unrelated to BP suggesting that factors other than adrenergic neural tone make a major contribution to OSAS-related hypertension. The results obtained in this pilot study need, however, to be confirmed in a larger study involving more patients. [source]

    Haemodynamic changes during positive-pressure ventilation in children

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2005
    A. Kardos
    Background:, Positive-pressure ventilation may alter cardiac function. Our objective was to determine with the use of impedance cardiography (ICG) whether altering airway pressure modifies the central haemodynamics in mechanically ventilated children with no pulmonary pathology. Central venous saturation (ScvO2) was measured as an indicator of tissue perfusion. Methods:, Twelve children between 7 and 65 months of age, requiring mechanical ventilation as a consequence of a non-pulmonary disease, were enrolled in the study. All patients had a central venous line as a part of their routine management. Using pressure controlled ventilation (PCV) the baseline PEEP value of 5 cmH2O (Pb5) was increased to 10 cmH2O (Pi10) and then to 15 cmH2O (Pi15). After Pi15, PEEP was decreased to 10 (Pd10) and then to 5 cmH2O (Pd5). Each time period lasted 5 min heart rate (HR), mean arterial blood pressure (MABP), central venous pressure (CVP), end-tidal carbon dioxide (ETCO2), mean airway pressure (Paw), stroke volume index (SVI), cardiac index (CI) and central venous oxygen saturation (ScvO2) were recorded at the end of the five periods. Results:, The values of CI did not change when 10 and 15 cmH2O of PEEP were applied. Elevation of PEEP and thus Paw caused slight but not significant reductions in SVI and ScvO2 as compared to the baseline (Tb5). After reducing PEEP in Td5 we found statistically significant elevations of SVI and CI, as compared to Ti15 heart rate, ETCO2 and MABP remained unchanged. Conclusion:, We did not find significant haemodynamic changes following PEEP elevation in ventilated children, as measured using impedance cardiography. Reducing the value of PEEP to 5 cmH2O resulted in statistically significant SVI elevations. The values of ScvO2 remained unaffected. [source]

    Ventilator treatment in the Nordic countries.

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2002
    A multicenter survey
    Background: A 1-day point prevalence study was performed in the Nordic countries to identify ventilator-treatment strategies in the region. Material and methods: On 30 May 30 2001 all mechanically ventilated patients in 27 intensive care units (ICUs) were registered via the internet. The results are shown as medians (25th, 75th percentile). Results: ,One hundred and eight patients were included (69% male) with new simplified acute physiology score (SAPS) 48 (37,57) and 4.5 d (2,11) of ventilator treatment. The most frequent indication for ventilator treatment was acute respiratory failure (73%). Airway management was by endotracheal tube (64%), tracheostomy (32%) and facial mask (4%). Pressure regulated ventilator modes were used in 86% of the patients and spontaneous triggering was allowed in 75%. The tidal volume was 7 ml/kg (6,9), peak inspiratory pressure 22 cmH2O (18,26) and positive end-expiratory pressure (PEEP) 6 cmH2O (6,9). FiO2 was 40% (35,50), SaO2 97% (95,98), PaO2 11 kPa (10,13), PaCO2 5.4 kPa (4.7,6.3), pH 7.43 (7.38,7.47) and BE 2.0 mmol/l (, 0.5,5). The PaO2/FiO2 ratio was 220 mmHg (166,283). The peak inspiratory pressure (r=0.37), mean airway pressure (r=0.36), PEEP (r=0.33), tidal volume (r=0.22) and SAPS score (r=0.19) were identified as independent variables in relation to the PaO2/FiO2 ratio. Conclusion: The vast majority of patients were ventilated with pressure-regulated modes. Tidal volume was well below what has been considered conventional in recent large trials. Correlations between the parameters of gas exchange, respiratory mechanics, ventilator settings and physiological status of the patients was poor. It appears that blood gas values are the main tool used to steer ventilator treatment. These results may help to design future interventional studies of ventilator treatment. [source]

    Reflection on a patient's airway management during a ward-based resuscitation

    NURSING IN CRITICAL CARE, Issue 5 2006
    Carolyn Shepherd
    Abstract Background: The bag-valve-mask (BVM) system is a common adjunct used during adult resuscitation to ventilate the lungs and deliver oxygen to patients in cardiopulmonary arrest. Gastric inflation, regurgitation and aspiration are well-documented complications of BVM ventilation, which can have serious consequences for patients. Aim: The aim of this paper is to review the cause of gastric inflation, regurgitation and aspiration during BVM ventilation and to consider techniques that have been suggested to reduce these problems.Method: Using a reflective model, the author revisits an actual cardiac arrest, and within a structured framework considers the event itself, the context of the event and looks at ways in which practice could be improved in future.Results: It is clear from the evidence that a reduction in peak airway pressure can reduce the risk of gastric inflation, regurgitation and aspiration. A review of the available research strongly suggests that in expert hands, the most effective means of reducing peak airway pressure is by reducing tidal volume by using a smaller bag.Conclusion: Although the evidence, as presented, for a reduction in bag size is convincing, there appears to be a problem that less regular users do not appear to be able to produce effective tidal volumes when using a smaller bag. If a reduced bag size is standardized, further research using a diverse group of health care workers with the BVM is required before a clear policy can be achieved. It is likely that training and practice will be shown to be important for nursing staff expected to use the smaller BVM. [source]