A study in the November 11 issue of JAMA indicates that positioning patients with acute respiratory distress syndrome (ARDS) in prone position while receiving mechanical ventilation does not significantly lower the risk of death compared to similar patients positioned lying face up during ventilation.
Currently, prone positioning is suggested for patients with ARDS, for whom various factors makes mechanical ventilation potentially injurious, according to an announcement about the study findings from the American Medical Association (AMA).
Paolo Taccone, MD, of Fondazione IRCCS–“Ospedale Maggiore Policlinico, Mangiagalli, Regina Elena” di Milano, Milan, Italy, and colleagues conducted a trial to detect potential survival benefit of prone positioning in patients with moderate and severe hypoxemia who are affected by ARDS. The randomized controlled trial was conducted in 23 centers in Italy and two in Spain. A total of 342 adult patients with ARDS receiving mechanical ventilation were included. All study participants were enrolled from February 2004 through June 2008 and stratified into subgroups with moderate (n = 192) and severe (n = 150) hypoxemia. Patients were randomized to undergo supine (n = 174) or prone (20 hours per day; n = 168) positioning during ventilation.
Prone and supine patients from the entire study population had similar 28-day (31.0% vs. 32.8%) and 6-month (47.0% vs. 52.3%) mortality rates, despite significantly higher complication rates in the prone group.
“Outcomes were also similar for patients with moderate hypoxemia in the prone and supine groups at 28 days (25.5% vs. 22.5%) and at 6 months (42.6% vs. 43.9%). The 28-day mortality of patients with severe hypoxemia was 37.8% in the prone and 46.1% in the supine group, while their 6-month mortality was 52.7% and 63.2%, respectively,” write the authors.
They authors add that median (midpoint) Sequential Organ Failure Assessment (SOFA) scores, ventilator-free days, and intensive care unit length of stay were also similar between the different groups of patients.
“Do the findings of this trial, together with those of previous studies, represent the end of the prone position technique? Undoubtedly, the data of the present trial together with previous results clearly indicate that prolonged prone positioning, in the unselected ARDS population, is not indicated as a treatment. However, its potential role in patients with the most severe hypoxemia, for whom the possible benefit could outweigh the risk of complications, must be further investigated, considering the strong pathophysiological background, the post hoc result of our previous study, the most recent meta-analysis, and the favorable trend observed prospectively in this study,” conclude the authors.