The Role of VV-ECMO in Severe COVID-19 ARDS

Abstract

Although an established practice in potentially reversible severe respiratory failure, extracorporeal membrane oxygenation (ECMO) support remains controversial. Over the last 50 years, only 4 large scale randomised controlled trials relating to ECMO have been conducted in patients with ARDS. A meta-analysis of only 2 studies has demonstrated survival benefit in those supported with ECMO compared to optimal conventional therapy. With the advent of the COVID pandemic, ECMO utilisation increased, the guidelines evolved, and an unprecedented number of patients were referred for and managed with ECMO support. Approximately 15,000 patients have been supported to date, predominantly using veno-venous ECMO, with an overall in-hospital 90-day mortality of 47%. Although published data reported an increase in ECMO mortality to nearly 60% as the pandemic progressed, this was likely multifactorial, as subsequent data has demonstrated more promising mortality results. This highlights the unique challenges pertaining to patient selection and implementation of this finite support amid an evolving pandemic with many unknowns. Judicious and ethical patient selection is essential to ensure use for the greatest benefit. In this chapter we will outline the unique pathophysiology and clinical features of COVID-ARDS, indications for ECMO referral and patient selection, and implementation during the COVID-19 pandemic.