Physiologic Wins Without Survival Gain? Prone Positioning in VV-ECMO-Treated ARDS

Background: Prone positioning (PP) is a well-established strategy to improve oxygenation in Acute Respiratory Distress Syndrome (ARDS) patients; however, its role during Venovenous Extracorporeal Membrane Oxygenation (VV-ECMO) remains uncertain.Objective: To evaluate the impact of PP on Intensive Care Unit (ICU) survival and respiratory parameters in patients with ARDS supported by VV-ECMO.Methods: This retrospective observational study included 100 adult patients who underwent VV-ECMO for respiratory failure between 2015 and 2024. Patients were divided into two groups: hose who received prone positioning during ECMO (≥16 hours) and those who remained supine. Clinical characteristics, ventilatory parameters, and outcomes were compared.Results: Forty-five patients (45%) underwent PP during ECMO. Although ICU survival was higher in the prone group (53.7% vs. 46.3%), the difference was not statistically significant (p=0.246). However, PP was associated with significant improvements in driving pressure, mechanical power, compliance, and gas exchange indices in the post-prone period.Conclusion: While PP during VV-ECMO did not significantly improve survival, it contributed to favorable physiological changes, supporting its use as an adjunctive therapy in ARDS management under ECMO.