Veno-venous extracorporeal membrane oxygenation for severe COVID-19 associated acute respiratory distress syndrome: A retrospective, nationwide, Danish cohort study

Background: Severe acute respiratory syndrome (ARDS) may require veno-venous extracorporeal membrane oxygenation (V-V ECMO). The aim of this study was to provide data on patient selection and outcome in a nationwide cohort study of patients with COVID-19 associated ARDS supported with V-V ECMO. Methods: We identified all patients with COVID-19, who were supported with V-V ECMO in Denmark from March 10, 2020, to December 31, 2021, and retrieved data on patients who were referred to- and accepted for ECMO, demographics, outcome data, and complications. Risk factors for mortality were analysed using multivariate Cox regression analysis. Results: During the study period, 1836 patients were admitted to Danish intensive care units (ICUs). In the same period, there were 197 enquiries for ECMO of whom 118 patients were considered eligible. Overall, 71 patients were cannulated for ECMO; three patients were cannulated for veno-arterial extracorporeal membrane oxygenation (V-A ECMO) due to right sided heart failure and 68 patients were cannulated for V-V ECMO. Two patients accepted for V-V ECMO died during cannulation. The median age was 55 years (IQR 45-60) and 66% were males. The median duration of ECMO support was 13 days (IQR 7-21), mechanical ventilation median 26 days (IQR 14-42), ICU stay median 34 days (IQR 17-46), and length of hospital stay median 41 days (IQR 25-56). Ninety-day mortality was 43%. Age of 60 years or more was associated with an increased risk of mortality. Pre-existing hypertension was associated with a decreased risk of mortality. Conclusion: A nationwide, Danish cohort study of 68 COVID-19 patients supported with V-V ECMO, showed a 90-day survival of 43%, which is in accordance with reports from comparable cohorts. Age of 60 years or more was associated with an increased risk of mortality. Pre-existing hypertension was associated with a decreased risk of mortality.