Fekri Abroug, Lamia Ouanes-Besbes, Fahmi Dachraoui, Islem Ouanes, Laurent Brochard; Critical Care 2011, 15:R6 (6 January 2011)
Introduction: In patients with acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS), recent randomised controlled trials (RCTs) showed a consistent trend of mortality reduction with prone ventilation. We updated a meta-analysis on this topic.
Methods: RCTs that compared ventilation of adult patients with ALI/ARDS in prone versus supine position were included in this study-level meta-analysis. Analysis was made by a random-effects-model. The effect-size on intensive care unit (ICU) mortality was computed in the overall included studies and in two subgroups of studies: those that included all ALI or hypoxemic patients, and those that restricted inclusion to only ARDS patients. A relationship between studies’ effect-size and daily prone duration was sought with meta-regression. We also computed the effects of prone positioning on major adverse airway complications.
Results: Seven RCTs (including 1675 adult patients of whom 862 ventilated in prone position) were included. The four most recent trials included only ARDS patients, and also applied the longest proning durations and used lung-protective ventilation. The effects of prone positioning differed according to the type of studies. Overall, prone ventilation did not reduce ICU mortality (OR=0.91, 95% CI: 0.75 to 1.2; P=0.39), but it significantly reduced the ICU mortality in the four recent studies that enrolled only patients with ARDS (OR: 0.71; 95% CI: 0.5-0.99; P=0.048; NNT: 11). Meta-regression on all studies disclosed only a trend to explain effect variation by prone duration (P=0.06). Prone positioning was not associated with a statistical increase in major airway complications.
Conclusions: Long duration of ventilation in prone position significantly reduces ICU mortality when only ARDS patients are considered.
Weblink here