Extracorporeal membrane oxygenation versus mechanical ventilation alone in adults with severe acute respiratory distress syndrome: A systematic review and meta-analysis

Background: COVID-19 can lead to acute respiratory distress syndrome (ARDS). Extracorporeal membrane oxygenation (ECMO) is considered to be a salvage strategy for severe ARDS. However, the effect of ECMO therapy on severe ARDS remains inconclusive. We aimed to evaluate the effects of ECMO for adults with severe ARDS.

Methods: We searched six databases (EMBASE, Medline, the Cochrane Library, Web of Science, Wanfang databases and CNKI) from inception to May 2020 to screen relevant high-quality observational studies and randomised controlled trials. We used the random effects model for outcome calculation. Trial sequential analysis (TSA), heterogeneity, sensitivity analysis and publication bias were explored. The primary outcome was 90-day mortality.

Results: Seven studies (two RCTs and five observational studies) with a total of 867 patients were included. Compared with MV therapy alone, ECMO therapy significantly reduced the mortality at 90 days (based on RCT studies, Risk Ratio [RR] 0.74, 95% confidence Interval (CI) 0.59-0.93, P = .01, I² = 0%, moderate quality; based on observational studies, RR 0.61, 95% CI 0.46-0.81, P < .001, I² = 0%, low quality) and at 30 and 60 days. TSA results were consistent with the primary outcome. Furthermore, device-related adverse events were similar between the ECMO group and MV alone group (RR, 2.09; 95% CI, 0.27-16.03, P = .48, I² = 0%, moderate quality).

Conclusions: This study showed that the ECMO group exhibited a significantly lower mortality rate compared with the MV alone group at 90, 30 and 60 days for severe ARDS patients.