Higher mortality in Extracorporeal Membrane Oxygenation patients during the COVID-19 pandemic compared with H1N1 influenza: implications for future pandemics.

BACKGROUND

Veno-venous Extracorporeal Membrane Oxygenation (V-V ECMO) in management of refractory respiratory failure due to viral respiratory infections has increased with recent pandemics.

AIMS: The aim was to compare clinical characteristics and outcomes of patients requiring ECMO support during an evolving pandemic with COVID-19, with patients during the H1N1-influenza pandemic and subsequent seasonal epidemics, where adjunct therapy and vaccination was available.

METHODS

Medical records of inpatients at an ECMO referral centre diagnosed with COVID-19 between March 2020 and October 2022 and requiring ECMO support were analysed. The clinical characteristics and outcomes of these patients were compared to data from patients with H1N1 influenza requiring ECMO between July 2009 and August 2017, treated at the same centre. The primary outcome of in-hospital mortality was analysed with a multivariate logistic regression model; categorical and continuous variables were compared using Fisher's exact tests and two-sample T-tests, respectively.

RESULTS

ECMO was used in 27 COVID-19 patients and 32 H1N1 influenza patients. Compared with H1N1 patients, COVID-19 patients were older (49.2 ± 9.0 vs 42.3 ± 11.1 years,p = 0.01), and more likely to have comorbidities (59 % vs 28 %,p = 0.02). Mortality was significantly higher for COVID-19 patients (52 % vs 6 %,p < 0.0001), odds ratio 16.8 (95 % CI: 1.27-221.39,p < 0.05). Days on ECMO were longer in the COVID-19 group (20 ± 13.3 vs 10 ± 5.6 days,p < 0.001). ECMO-related complication rates were similar between groups, apart from higher rates of secondary blood stream infections in COVID-19 patients (44 % vs 6 %,p < 0.001).

CONCLUSION

Outcomes in patients with COVID-19 requiring ECMO support were worse than those requiring similar support during H1N1 seasons.