Extracorporeal membrane oxygenation for COVID-19: An evolving experience through multiple waves.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has shown variable results in COVID-19 pneumonia however, some evidence supports benefit. Here we compare our institution's ECMO outcomes across multiple waves of the COVID-19 pandemic. METHODS: All patients who received ECMO for COVID-19 between March 1, 2020, and March 1, 2021, were reviewed. Patients received venovenous (VV) or right ventricular assist device (RVAD/ECMO) ECMO. Early (March 1-July 6, 2020, Era 1) and late (July 7, 2020-March 1, 2021, Era 2) pandemic RVAD/ECMO patients were compared. RESULTS: Fifty-four patients received ECMO of which 16 (29.6%) patients received VV ECMO and 38 (70.4%) RVAD/ECMO. Median age was 53.0 years, body mass index 36.1 kg/m2 , 41.2% female, and 49% Caucasian. The most common pre-cannulation treatments included steroids (79.6%) and convalescent plasma (70.4%). Median time from admission to cannulation was 7.0 days. Median support time was 30.5 days (VV ECMO 35.0 days, RVAD/ECMO 26.0 days). In- hospital mortality was 42.6% (39.5% RVAD/ECMO, 50.0% VV ECMO). Significant morbidities included infection (80.8%), bleeding events (74.5%), and renal replacement therapy (30.8%). Cumulative mortality 120-days post-cannulation was 45.7% (VV ECMO 60.8%, RVAD/ECMO 40.0%). RVAD/ECMO Era 1 demonstrated a significantly lower cumulative mortality (16.2%) compared to Era 2 (60.4%). Competing risk analysis found age (HR 0.95, [95% CI 0.92, 0.98] p = 0.005) to be a protective factor for survival. CONCLUSION: ECMO support for COVID-19 is beneficial but carries significant morbidity. RVAD/ECMO support demonstrated consistent advantages in survival to VV-ECMO, but with declining efficacy across time during the COVID-19 pandemic.