Prone positioning in acute respiratory distress syndrome: why aren’t we using it more?

Acute respiratory distress syndrome (ARDS) is defined by acute onset of bilateral lung infiltrates with impaired gas exchange that is not entirely due to congestive heart failure (1). Strategies to manage ARDS are primarily supportive, with the bulk of the evidence suggesting that improvement in mortality is achieved with optimal setting of mechanical ventilation (2). The mortality rate due to ARDS remains unacceptably high at 30–40%, and a number of recent studies have examined the impact of prone positioning (PP) in ARDS as a life-saving intervention (3,4). The concept of proning patients on mechanical ventilation was proposed in the 1970s and has been used for several decades, although definitive mortality outcome data were only available more recently with the publication of the PROSEVA trial in 2013 and subsequent meta-analyses (3,4)