Comparison of venovenous extracorporeal membrane oxygenation, prone position and supine mechanical ventilation for severely hypoxemic acute respiratory distress syndrome: a network meta-analysis

Intensive Care Med. 2024 Jul;50(7):1021-1034. doi: 10.1007/s00134-024-07492-7. Epub 2024 Jun 6.


Purpose: Severe acute respiratory distress syndrome (ARDS) with PaO2/FiO2 < 80 mmHg is a life-threatening condition. The optimal management strategy is unclear. The aim of this meta-analysis was to compare the effects of low tidal volumes (Vt), moderate Vt, prone ventilation, and venovenous extracorporeal membrane oxygenation (VV-ECMO) on mortality in severe ARDS.

Methods: We performed a frequentist network meta-analysis of randomised controlled trials (RCTs) with participants who had severe ARDS and met eligibility criteria for VV-ECMO or had PaO2/FiO2 < 80 mmHg. We applied the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to discern the relative effect of interventions on mortality and the certainty of the evidence.

Results: Ten RCTs including 812 participants with severe ARDS were eligible. VV-ECMO reduces mortality compared to low Vt (risk ratio [RR] 0.77, 95% confidence interval [CI] 0.59-0.99, moderate certainty) and compared to moderate Vt (RR 0.75, 95% CI 0.57-0.98, low certainty). Prone ventilation reduces mortality compared to moderate Vt (RR 0.78, 95% CI 0.66-0.93, high certainty) and compared to low Vt (RR 0.81, 95% CI 0.63-1.02, moderate certainty). We found no difference in the network comparison of VV-ECMO compared to prone ventilation (RR 0.95, 95% CI 0.72-1.26), but inferences were based solely on indirect comparisons with very low certainty due to very wide confidence intervals.

Conclusions: In adults with ARDS and severe hypoxia, both VV-ECMO (low to moderate certainty evidence) and prone ventilation (moderate to high certainty evidence) improve mortality relative to low and moderate Vt strategies. The impact of VV-ECMO versus prone ventilation remains uncertain.

Keywords: Acute respiratory distress syndrome; Critical care; Extracorporeal life support; Intensive care units; Meta-analysis; Prone position.

Publication types

  • Meta-Analysis
  • Comparative Study
  • Systematic Review

MeSH terms

  • Extracorporeal Membrane Oxygenation* / methods
  • Extracorporeal Membrane Oxygenation* / mortality
  • Humans
  • Hypoxia / mortality
  • Hypoxia / therapy
  • Network Meta-Analysis*
  • Prone Position / physiology
  • Randomized Controlled Trials as Topic
  • Respiration, Artificial* / methods
  • Respiration, Artificial* / statistics & numerical data
  • Respiratory Distress Syndrome* / mortality
  • Respiratory Distress Syndrome* / physiopathology
  • Respiratory Distress Syndrome* / therapy
  • Supine Position
  • Tidal Volume / physiology