CLINICAL OUTCOMES OF PRONE POSITIONING IN PATIENTS WITH ACUTE RESPIRATORY DISTRESS SYNDROME: A SYSTEMATIC REVIEW OF RANDOMIZED AND OBSERVATIONAL STUDIES

Abstract Background: Prone positioning is a recommended intervention for patients with moderate to severe acute respiratory distress syndrome (ARDS). Its physiologic benefits include improved oxygenation and lung mechanics. Its impact on mortality, especially in patients receiving extracorporeal membrane oxygenation (ECMO), is variable. We aimed to systematically review the clinical outcomes of prone positioning in adult ARDS patients, including those supported with mechanical ventilation or veno-venous ECMO. Methods: This review according to PRISMA 2020 guidelines. A search was conducted in PubMed, Scopus, Web of Science, and Google Scholar for English-language studies published between 2010 and 2025. Randomized controlled trials, cohort studies, and case series were included. We include studies in prone positioning outcomes in adult ARDS patients receiving mechanical ventilation or ECMO. Data were extracted on mortality, oxygenation indices (PaO₂/FiO₂), ventilation duration, ECMO weaning, and complications. Results: Eleven studies were included (2 randomized controlled trials, 6 cohort studies, 2 case series, and 1 propensity-matched study). Most studies reported improved oxygenation after prone positioning. Several studies identified early PaO₂/FiO₂ improvement as a survival predictor. Mortality was lower in early and prolonged prone sessions, mainly when used in conjunction with lung-protective ventilation. In ECMO patients, prone positioning was feasible, improved oxygenation, and was not associated with increased complications. Not all studies show statistically significant survival benefits. Conclusion: Prone positioning improves oxygenation and reduce mortality in moderate to severe ARDS, mainly when applied early and for ≥12 hours per session. It is safe in patients receiving ECMO, with oxygenation response serving as a prognostic marker.