Acute Respiratory Distress Syndrome (ARDS) Clinical Trials

Treatment of acute respiratory distress syndrome (ARDS) relies on invasive mechanical ventilation with supposedly protective settings (low tidal volume ventilation). Mortality of ARDS remains high in observational studies (40 to 50%). Approximately 30% of ARDS patients exhibit tidal hyperinflation despite low tidal volume ventilation, suggesting that personalization of tidal volume is required to improve ARDS prognostic. To date, reliable bedside tools to adjust tidal volume are lacking. Excessive tidal volume can be detected using computed tomography by quantification of tidal hyperinflation, but this technique is reserved to research studies and requires patient transport to imaging facility. Mechanical ventilation generates cardio-pulmonary interaction, whose magnitude is influenced by tidal volume and respiratory system characteristics. Pulse pressure variation is a bedside tool with potential to quantify cardio-pulmonary interactions. Increasing tidal volume will decrease right ventricular preload and increase right ventricular afterload, hence maximizing cardio-pulmonary interactions. The investigators hypothesize that pulse pressure variation might help to detect excessive tidal volume during a tidal volume challenge (i.e. stepwise increase in tidal volume)