Unraveling the (patho)physiological Mechanisms and Potential Clinical Benefits of an Early Switch from Controlled to Assisted Ventilation

What this Trial Is About

Researchers are evaluating the physiological effects and possible clinical benefits of switching early from controlled to assisted ventilation in adult patients who are mechanically ventilated due to acute hypoxemic respiratory failure, characterized by a PaO2/FiO2 ratio less than 200 mmHg. This study focuses on how this early switch impacts lung stress and lung function, as there is currently no guidance on the optimal timing for changing ventilation modes in these patients. Participants will be switched from controlled ventilation to assisted ventilation when their PaO2/FiO2 ratio improves to above 200 mmHg. Before the switch, patients will undergo lung imaging and perfusion assessments using electrical impedance tomography and photon-counting CT scans. After the switch, continuous monitoring of lung function, pressure, and breathing effort will take place for up to 72 hours or until the switch is deemed unsuccessful. Success is defined as maintaining assisted ventilation for 72 hours, while failure involves returning to controlled ventilation for more than 2 hours within that period. During the study, participants will be closely monitored through various lung and breathing assessments, including electrical impedance tomography, esophageal and gastric pressure measurements, and respiratory mechanics. Researchers will measure lung stress, ventilation/perfusion mismatch, breathing effort, gas exchange, inflammatory biomarkers, and other respiratory and hemodynamic parameters. The primary outcome is the change in regional lung stress over 72 hours. The study participation spans from initial ventilation mode switch to monitoring for up to 72 hours post-switch, with additional follow-up assessments twice daily until study completion or switch failure.

Early Switch from Controlled to Assisted Ventilation