Search results for "Tidal Volume"
showing 10 items of 75 documents
Differences in the Response to Methacholine Between the Tidal Breathing and Dosimeter Methods
2008
Background It has been postulated that differences in provocative concentration of methacholine causing a 20% fall in FEV 1 (PC 20 ) values between the dosimeter method and tidal breathing method might be due to differences in the dose of agonist delivered to the mouth. The aim of the present study was to determine the influence of the dose of aerosol delivered to the mouth on differences in the response obtained with each challenge method. Methods This study measured airway responsiveness to methacholine by dosimeter method and tidal breathing method in 27 subjects with suspected asthma. The dosimeter was modified to deliver an identical volume to that obtained with the tidal breathing met…
Effectiveness and safety of a new helmet CPAP configuration allowing tidal volume monitoring in patients with COVID-19.
2021
Abstract Background High generated tidal volumes (Vt) have been correlated with higher risk of self-induced lung injury and worse clinical outcome. This study aimed to evaluate the effectiveness and safety of a new helmet continuous positive airway pressure delivered (h-CPAP) configuration allowing Vt monitoring in patients affected by COVID-19. Methods This prospective observational study was performed in the respiratory intermediate care unit of University Hospital in Turin, Italy, between March 24th, and June 15th, 2020. Included patients were treated with CPAP via a single-limb intentional leak configuration by a turbine-driven ventilator, provided with a dedicated patch. Effectiveness …
Personalised mechanical ventilation tailored to lung morphology versus low positive end-expiratory pressure for patients with acute respiratory distr…
2019
The effect of personalised mechanical ventilation on clinical outcomes in patients with acute respiratory distress syndrome (ARDS) remains uncertain and needs to be evaluated. We aimed to test whether a mechanical ventilation strategy that was personalised to individual patients' lung morphology would improve the survival of patients with ARDS when compared with standard of care.We designed a multicentre, single-blind, stratified, parallel-group, randomised controlled trial enrolling patients with moderate-to-severe ARDS in 20 university or non-university intensive care units in France. Patients older than 18 years with early ARDS for less than 12 h were randomly assigned (1:1) to either th…
Tidal volume and helmet: Is the never ending story coming to an end?
2021
Noninvasive ventilation (NIV) has been increasingly used in acute care setting with various indications, but its use in patients with acute hypoxemic respiratory failure (AHRF) is controversial. In this setting, reliable monitoring of Vt and unintentional leaks is of the utmost importance. The aim of this article is to describe the importance of tidal volume measurement in the context of AHRF treated with NIV.
Comparative bench study evaluation of different infant interfaces for non-invasive ventilation
2018
Abstract Background To compare, in terms of patient-ventilator interaction and performance, a new nasal mask (Respireo, AirLiquide, FR) with the Endotracheal tube (ET) and a commonly used nasal mask (FPM, Fisher and Paykel, NZ) for delivering Pressure Support Ventilation (PSV) in an infant model of Acute Respiratory Failure (ARF). Methods An active test lung (ASL 5000) connected to an infant mannequin through 3 different interfaces (Respireo, ET and FPM), was ventilated with a standard ICU ventilator set in PSV. The test lung was set to simulate a 5.5 kg infant with ARF, breathing at 50 and 60 breaths/min). Non-invasive ventilation (NIV) mode was not used and the leaks were nearly zero. Res…
A simple method of bronchoprovocation using a valved holding chamber.
2004
This study was undertaken to ascertain whether the use of a valved holding chamber (VHC) during bronchial provocation testing might increase lung deposition and repeatability of the test relative to the tidal breathing method. The 2-min tidal breathing results were compared to five inhalations from a VHC device in patients using the Pari-provoII nebulizer (MMD = 2.1mkm). Lung and mouth deposition, losses though the exhaled air and losses before aerosol delivery to the patient's mouth were measured in patients using a radiolabeled 99Tc-DTPA solution and gamma camera. The study revealed that lung deposition was 67% with the VHC method, and losses with exhaled air were 29% of the inhaled amoun…
Functional Analysis in Single-Lung Transplant Recipients
2004
Objective To develop and evaluate a postprocessing tool to quantify ventilated split-lung volumes on the basis of 3 He-MRI and to apply it in patients after single-lung transplantation (SLTX). High-resolution CT (HRCT) was employed as a reference modality providing split air-filled lung volumes. Lung volumes derived from pulmonary function test results served as clinical parameters and were used as the “gold standard.” Material and methods Eight patients (mean age, 54 years) with emphysema and six patients (mean age, 58 years) with idiopathic pulmonary fibrosis. All patients were evaluated following SLTX. HRCT was performed during inspiration (slice thickness, 1 mm; increment, 10 mm). For c…
Dynamic determination of oxygenation and lung compliance in murine pneumonectomy.
2011
Thoracic surgical procedures in mice have been applied to a wide range of investigations, but little is known about the murine physiologic response to pulmonary surgery. Using continuous arterial oximetry monitoring and the FlexiVent murine ventilator, the authors investigated the effect of anesthesia and pneumonectomy on mouse oxygen saturation and lung mechanics. Sedation resulted in a dose-dependent decline of oxygen saturation that ranged from 55% to 82%. Oxygen saturation was restored by mechanical ventilation with increased rate and tidal volumes. In the mouse strain studied, optimal ventilatory rates were a rate of 200/minute and a tidal volume of 10 mL/kg. Sustained inflation pressu…
Ventilator Settings to Avoid Nuisance Alarms During Mouthpiece Ventilation
2016
BACKGROUND: A recent study found that activation of disconnection and low-pressure alarms is common during mouthpiece ventilation and may represent a major limitation to its use. The aim of this bench study was: (1) to investigate the technical aspects that can influence the setting of the ventilator during mouthpiece ventilation and (2) to provide a practical setting strategy to avoid the alarm activation. METHODS: Eight life-support ventilators able to deliver volume controlled ventilation were tested in a bench study using a single-limb non-vented circuit configuration connected to a standard mouthpiece. Disconnection and apnea alarm were turned off or set at the least sensitive setting.…
Bi-Level ventilation decreases pulmonary shunt and modulates neuroinflammation in a cardiopulmonary resuscitation model
2020
Background Optimal ventilation strategies during cardiopulmonary resuscitation are still heavily debated and poorly understood. So far, no convincing evidence could be presented in favour of outcome relevance and necessity of specific ventilation patterns. In recent years, alternative models to the guideline-based intermittent positive pressure ventilation (IPPV) have been proposed. In this randomized controlled trial, we evaluated a bi-level ventilation approach in a porcine model to assess possible physiological advantages for the pulmonary system as well as resulting changes in neuroinflammation compared to standard measures. Methods Sixteen male German landrace pigs were anesthetized a…