Objectives: 

Limited data exist on outcomes in COVID-19- vs. influenza A (H1N1)-associated acute respiratory distress syndrome (ARDS) patients when supported on venovenous extracorporeal membrane oxygenation (ECMO). We aimed to compare acute brain injury (ABI) frequency, thrombotic, and hemorrhagic complications and mortality in COVID-19- vs. H1N1-associated ARDS patients on venovenous ECMO.

Design: 

Retrospective multicenter observational cohort study.

Setting: 

Data reported to the Extracorporeal Life Support Organization by up to 534 ECMO centers from 2009 to 2021.

Patients: 

Patients 18 years or older with COVID-19 or H1N1 requiring venovenous ECMO support.

Interventions: 

None.

Measurements and Main Results: 

We conducted a retrospective analysis on 2253 venovenous ECMO patients (1916 COVID-19 and 337 H1N1). We employed propensity score matching followed by multivariable logistic regression to compare outcomes. The primary outcome was ABI and secondary outcomes were thrombosis, hemorrhage, and mortality. After matching, 674 patients (337 COVID and 337 H1N1) remained (median age = 41, 55% male). In the matched cohort, 10% of COVID-19 patients experienced ABI compared with 12% of H1N1 patients, with no significant difference between the groups (adjusted odds ratio [aOR], 0.83; 95% CI, 0.44–1.54; p = 0.53). There was no difference in thrombotic complications (aOR, 0.67; 95% CI, 0.44–1.02; p = 0.06), but COVID-19 patients had fewer hemorrhagic complications (aOR, 0.27; 95% CI, 0.17–0.42; p < 0.001) compared with H1N1. Mortality was higher in COVID patients (aOR, 2.17; 95% CI, 1.45–3.23; p < 0.001). In both groups, however, patients with ABI had higher mortality than those without, with 94% vs. 40% (p < 0.001) for COVID and 75% vs. 29% (p < 0.001) for H1N1, respectively.

Conclusions: 

COVID-19 and H1N1 patients on venovenous ECMO exhibited similar ABI frequency, which was twice that observed in the general historical ARDS patients supported on venovenous ECMO population. Our findings highlight that both COVID and H1N1 ARDS increase ABI frequency in ECMO patients. Finally, the presence of ABI doubled mortality among both COVID and H1N1.