Avalanche Phenomenon During Airways Opening in Acute Respiratory Distress Syndrome

What this Trial Is About

Acute respiratory distress syndrome (ARDS) affects many patients who require mechanical ventilation and is linked to a high risk of death. Mechanical ventilation, while life-saving, can worsen lung injury through lung overdistension and repeated airway opening and closing, known as atelectrauma. This study investigates a phenomenon called the "avalanche" effect during airway opening in ARDS, which has been suggested by animal and mathematical models but not yet observed in humans. Understanding this may help improve ventilation strategies and patient outcomes. Researchers will monitor airway pressure, flow, esophageal pressure, and ventilation distribution using electrical impedance tomography in patients with ARDS. The ventilator settings will be adjusted, including positive end-expiratory pressure set at 15 cmH2O for 10 minutes, followed by a decrease in respiratory rate and positive end-expiratory pressure to measure lung volume changes. Low-flow inflation and deflation pressure-volume curves will be performed before returning to standard ventilator settings. These procedures are part of usual care and patients will be followed until 28 days after inclusion or ICU discharge. Participants will have baseline data collected and undergo repeated assessments of lung function and ventilation mechanics. Researchers will measure the prevalence of the avalanche phenomenon during low-flow lung inflation and other lung pressure characteristics. Patient outcomes and characteristics will be compared based on the presence of this phenomenon. The study includes monitoring through measurements and imaging, with a focus on safety and collecting detailed data to better understand lung behavior in ARDS.

Avalanche Phenomenon During Airways Opening in Acute Respiratory Distress Syndrome