Extracorporeal membrane oxygenation in COVID-19 associated acute respiratory distress syndrome: A narrative review.

Venovenous extracorporeal membrane oxygenation (VV-ECMO) is an established rescue therapy in the management of refractory acute respiratory distress syndrome (ARDS). Although ECMO played an important role in previous respiratory viral epidemics, concerns about the benefits and usefulness of this technique were raised during the coronavirus disease 2019 (COVID-19) pandemic. Indeed, the mortality rate initially reported in small case series from China was concerning and exceeded 90%. A few months later, the critical care community published the findings from several observational cohorts on the use of extracorporeal membrane oxygenation (ECMO) in COVID-19-related ARDS. Contrary to the preliminary results, data from the first surge supported the use of ECMO in experienced centers because the mortality rate was comparable to those from the ECMO to Rescue Lung Injury in Severe ARDS (EOLIA) trial or other large prospective studies. However, the mortality rate of the population with severe disease evolved during the pandemic, in conjunction with changes in the management of the disease and the occurrence of new variants. The results from subsequent studies confirmed that the outcomes mainly depend on strict patient selection and center expertise. In comparison with non-COVID-related ARDS, the duration of ECMO for COVID-related ARDS was longer and increased over time. Clinicians and decision-makers must integrate this finding in the ECMO decision-making process to plan their ICU capacity and resource allocation. This narrative review summarizes the current evidence and specific considerations for ECMO use in COVID-19-associated ARDS.