Search results for "Tidal volume"
showing 10 items of 75 documents
Pulmonary effects of expiratory-assisted small-lumen ventilation during upper airway obstruction in pigs
2015
Summary Novel devices for small-lumen ventilation may enable effective inspiration and expiratory ventilation assistance despite airway obstruction. In this study, we investigated a porcine model of complete upper airway obstruction. After ethical approval, we randomly assigned 13 anaesthetised pigs either to small-lumen ventilation following airway obstruction (n = 8) for 30 min, or to volume-controlled ventilation (sham setting, n = 5). Small-lumen ventilation enabled adequate gas exchange over 30 min. One animal died as a result of a tension pneumothorax in this setting. Redistribution of ventilation from dorsal to central compartments and significant impairment of the distribution of ve…
Ventilation and Heart Rate Response During Exercise in Normals: Relevance for Rate Variable Pacing
1993
The observation of a close relationship of heart rate to oxygen uptake (HR-VO2) and heart rate to minute ventilation (HR-VE) has been shown to be of particular value in rate variable pacing. However, the impact of anaerobic threshold (AT) for the HR-VO2 and HR-VE slope has been studied less. Twenty-three male and 16 female subjects, mean age 52 +/- 7 years, were selected in whom complete heart catherization and extensive noninvasive studies excluded major cardiopulmonary disease. Semisupine bicycle exercise testing with analysis of respiratory gas exchange was performed using a ramping work rate protocol with work increments of 20 watts/min. At the respiratory AT, determined by the V slope …
Protective Mechanical Ventilation during General Anesthesia for Open Abdominal Surgery Improves Postoperative Pulmonary Function
2013
Abstract Background: The impact of intraoperative ventilation on postoperative pulmonary complications is not defined. The authors aimed at determining the effectiveness of protective mechanical ventilation during open abdominal surgery on a modified Clinical Pulmonary Infection Score as primary outcome and postoperative pulmonary function. Methods: Prospective randomized, open-label, clinical trial performed in 56 patients scheduled to undergo elective open abdominal surgery lasting more than 2 h. Patients were assigned by envelopes to mechanical ventilation with tidal volume of 9 ml/kg ideal body weight and zero-positive end-expiratory pressure (standard ventilation strategy) or tidal vol…
Ventilation volumes with different self-inflating bags with reference to the ERC guidelines for airway management: comparison of two compression tech…
2000
The 1998 ERC-guidelines for airway-management recommend an tidal volume of 400-600 ml for adults undergoing CPR. As commercially available self-inflating bags were designed to meet former recommendations (800-1200 ml) we investigated how to meet the latest recommendations with these bags. We combined the head of a training manikin (Laerdal Medical) and a standard lung (VTTL; Michigan Instrument), adjusted to a physiological compliance and resistance. Volume was measured with a Wright spirometer (BOC). Seven self-inflating bags were investigated. Tests were carried out by ten people (five female and five male) for 5 min each using two different techniques. Technique 1: standard ventilation w…
The bulbar respiratory centre in the rabbit. I. Changes of respiratory parameters caused by intermittent electrical bulbar stimulation during inspira…
1976
In anesthetized rabbits, spirogram and diaphragmatic activity were examined during electrical stimulation of the bulbar lateral reticular formation. The activity of bulbar respiratory neurons was recorded contra-or ipsilaterally to the stimulation site. One volley of repetitive stimuli per breath was delivered during either inspiration or expiration. 1. Each volley of about 120 ms duration at 100 pulses per second, delivered early ininspiration, caused an immediate and transient inhibition of the diaphragmatic activity. An inspiratory, rebound comprising lengthening of inspiration and increase in tidal volume occurred. a) “Inspiratory” and “expiratory-inspiratory” phase-spanning neurons exh…
New evidence in one-lung ventilation
2017
Mechanical ventilation in thoracic surgery has undergone significant changes in recent years due to the implementation of the protective ventilation. This review will analyze recent ventilatory strategies in one-lung ventilation. A MEDLINE research was performed using Mesh term "One-Lung Ventilation" including randomized clinical trials, metanalysis, reviews and systematic reviews published in the last 6 years. Search was performed on 21st March 2017. A total of 75 articles were initially found. After title and abstract review 14 articles were included. Protective ventilation is not simply synonymous of low tidal volume ventilation, but it also includes routine use of PEEP and alveolar recr…
Individualized versus fixed positive end-expiratory pressure for intraoperative mechanical ventilation in obese patients: a secondary analysis
2021
Background General anesthesia may cause atelectasis and deterioration in oxygenation in obese patients. The authors hypothesized that individualized positive end-expiratory pressure (PEEP) improves intraoperative oxygenation and ventilation distribution compared to fixed PEEP. Methods This secondary analysis included all obese patients recruited at University Hospital of Leipzig from the multicenter Protective Intraoperative Ventilation with Higher versus Lower Levels of Positive End-Expiratory Pressure in Obese Patients (PROBESE) trial (n = 42) and likewise all obese patients from a local single-center trial (n = 54). Inclusion criteria for both trials were elective laparoscopic abdominal…
Sigh in Patients With Acute Hypoxemic Respiratory Failure and ARDS
2021
Background Sigh is a cyclic brief recruitment maneuver: previous physiologic studies showed that its use could be an interesting addition to pressure support ventilation to improve lung elastance, decrease regional heterogeneity, and increase release of surfactant. Research Question Is the clinical application of sigh during pressure support ventilation (PSV) feasible? Study Design and Methods We conducted a multicenter noninferiority randomized clinical trial on adult intubated patients with acute hypoxemic respiratory failure or ARDS undergoing PSV. Patients were randomized to the no-sigh group and treated by PSV alone, or to the sigh group, treated by PSV plus sigh (increase in airway pr…
A New Configuration for Helmet Continuous Positive Airway Pressure Allowing Tidal Volume Monitoring
2020
We performed a bench and human study to test the hypothesis that a ventilator can accurately estimate Vt when a helmet is used in CPAP mode in a single limb configuration with an intentional leak port placed at the helmet expiratory port. We have recently demonstrated the effectiveness of this setup in bilevel mode
Analysis of atelectasis, ventilated, and hyperinflated lung during mechanical ventilation by dynamic CT.
2005
Study objective: To study the dynamics of lung compartments by dynamic CT (dCT) imaging during uninterrupted pressure-controlled ventilation (PCV) and different positive end-expiratory pressure (PEEP) settings in healthy and damaged lungs. Design: Experimental animal investigation. Setting: Experimental animal facility of a university department. Interventions: In seven anesthetized pigs, static inspiratory pressure volume curves were obtained to identify the individual lower inflection point (LIP) before and after saline solution lung lavage. During PCV, PEEP was adjusted 5 millibars (mbar) below the individually determined LIP (LIP - 5), at the LIP, and 5 mbar above the LIP (LIP + 5). Mea…