Venovenous ECMO treatment, outcomes, and complications in adults according to large case series: A systematic review.

Background: Venovenous extracorporeal membrane oxygenation (VV ECMO) has gained popularity for the treatment of refractory respiratory failure during and after the 2009 influenza pandemic, and still represents a precious therapeutic resource for severe novel coronavirus 2019 infection. However, most of the published studies are small case series, and only two randomized trials exist in literature.

Aim: Aim of this systematic review is to describe trends in VV ECMO treatment outcomes according to large studies only.

Methods: We searched and included studies with more than 100 VV ECMO cases dated up to August 1st, 2019.

Results: Thirty-three studies published in the period 2011-2019 met inclusion criteria, for a total of 12,860 patients (age 46.3 ± 17.4 years). ARDS was mainly by pneumonia, in 3126 (37%) cases; further 401(7%) patients had H1N1 Influenza A infection. Cannulation-related complications occurred in 502 (7%) cases. Weighted mean (95% confidence interval) of VV ECMO duration was 8.9 (8.7-9.1) days, and ICU stay was 23.6 (22.4-24.8) days. Mortality at the longest follow up available was 40%. Data collection in 70% of the studies had a duration of >5 years.

Conclusion: This study reveals the characteristics of large case VV ECMO studies.