Physiological Study of Prone Position in Acute Respiratory Failure Syndrome

ARDS is an acutely induced respiratory failure characterized by the appearance of bilateral alveolar opacities on imaging and hypoxemia Etiologies are divided into two classes: pulmonary, including all infectious pathologies, aspiration pneumonia, and drowning, and extra-pulmonary, induced by sepsis or acute pancreatitis. The mortality rate of ARDS remains high in unselected patient populations Among strategies that have proven beneficial in terms of patient outcome, prone positioning (PP) is associated with the greatest impact in terms of reduction in mortality. PP is currently recommended in the European guidelines for ARDS associated with a PaO2/FiO2 ratio \< 150 mmHg in patients in whom ventilatory settings have been optimized beforehand, The failure of early PP studies to demonstrate a survival benefit in ARDS was attributed to insufficient session duration. The PROSEVA study was the first to demonstrate that a PP duration of 17 h is associated with a reduction in mortality During the COVID-19 pandemic, several centers have reported the implementation of longer PP sessions. Two strategies have emerged from these studies. In one case, the patient was left in the prone position until the criteria for stopping PP were met. Thus, the PP/supine position alternation was completely suppressed. In another published strategy, PP sessions were maintained for a period covering two nights. Furthermore, in a multicenter retrospective study, PP sessions were maintained until clinical improvement was associated with reduced mortality. In this study of 263 patients, the median duration of PP in the extended duration group was 40 h, and 75% of the sessions lasted 48 h or less. Using a propensity score, the authors showed that patients treated with an extended PP duration had a lower 3-month mortality rate than patients in the standard duration group . This protocol was also associated with a 29% cumulative incidence of pressure sores, similar to the 25% cumulative incidence r