Despite a current suggestion that patients with acute respiratory distress syndrome be positioned lying face down while receiving mechanical ventilation, study results indicate that this positioning does not significantly lower the risk of death compared to similar patients positioned lying face up during ventilation, according to a study in the November 11 issue of JAMA.
Acute respiratory distress syndrome (ARDS) is a serious lung condition with a high mortality rate and may be associated with severe hypoxemia (abnormally low levels of oxygen in the blood, resulting in shortness of breath). Prone positioning is currently suggested for patients with ARDS, for whom various factors makes mechanical ventilation potentially injurious. "Moreover, prone positioning has been advocated as a rescue maneuver for severe hypoxemia, owing to its positive effects on oxygenation, which have been repeatedly documented since its first description in 1976. However, no randomized clinical trial has yet demonstrated a significant reduction in mortality rate associated with prone positioning," the authors write.
Paolo Taccone, M.D., of Fondazione IRCCS-"Ospedale Maggiore Policlinico, Mangiagalli, Regina Elena" di Milano, Milan, Italy, and colleagues conducted a trial to detect the 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 2 in Spain. The study included 342 adult patients with ARDS receiving mechanical ventilation, 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 (lying face up; n = 174) or prone (20 hours per day; n = 168) positioning during ventilation.