Extracorporeal membrane oxygenation support in COVID-19: an international cohort study of the Extracorporeal Life Support Organization registry

Abstract

Background: Multiple major health organisations recommend the use of extracorporeal membrane oxygenation (ECMO) support for COVID-19-related acute hypoxaemic respiratory failure. However, initial reports of ECMO use in patients with COVID-19 described very high mortality and there have been no large, international cohort studies of ECMO for COVID-19 reported to date.

Methods: We used data from the Extracorporeal Life Support Organization (ELSO) Registry to characterise the epidemiology, hospital course, and outcomes of patients aged 16 years or older with confirmed COVID-19 who had ECMO support initiated between Jan 16 and May 1, 2020, at 213 hospitals in 36 countries. The primary outcome was in-hospital death in a time-to-event analysis assessed at 90 days after ECMO initiation. We applied a multivariable Cox model to examine whether patient and hospital factors were associated with in-hospital mortality.

Findings: Data for 1035 patients with COVID-19 who received ECMO support were included in this study. Of these, 67 (6%) remained hospitalised, 311 (30%) were discharged home or to an acute rehabilitation centre, 101 (10%) were discharged to a long-term acute care centre or unspecified location, 176 (17%) were discharged to another hospital, and 380 (37%) died. The estimated cumulative incidence of in-hospital mortality 90 days after the initiation of ECMO was 37·4% (95% CI 34·4-40·4). Mortality was 39% (380 of 968) in patients with a final disposition of death or hospital discharge. The use of ECMO for circulatory support was independently associated with higher in-hospital mortality (hazard ratio 1·89, 95% CI 1·20-2·97). In the subset of patients with COVID-19 receiving respiratory (venovenous) ECMO and characterised as having acute respiratory distress syndrome, the estimated cumulative incidence of in-hospital mortality 90 days after the initiation of ECMO was 38·0% (95% CI 34·6-41·5).

Interpretation: In patients with COVID-19 who received ECMO, both estimated mortality 90 days after ECMO and mortality in those with a final disposition of death or discharge were less than 40%. These data from 213 hospitals worldwide provide a generalisable estimate of ECMO mortality in the setting of COVID-19.

Funding: None.

Figure 1

Stacked bar plots of disposition over time for patients with COVID-19 who received ECMO ECMO=extracorporeal membrane oxygenation. LTAC=long-term acute care. Discharged (home or rehab) refers to patients who were discharged to home or an acute rehabilitation centre. Discharged (LTAC or unspecified) refers to patients who were discharged to an LTAC centre or to an unspecified location. Discharge (hospital) refers to patients who were discharged to another hospital. Unknown status (censored) refers to patients who at the time of data analysis did not meet one of the following three criteria: (1) died, (2) discharged alive, or (3) survived at least 90 days after ECMO initiation. Hospitalised patients are those still in hospital at the Extracorporeal Life Support Organization Centre where ECMO support was delivered.

Figure 2

Cumulative incidence of mortality from time of ECMO initiation ECMO=extracorporeal membrane oxygenation. The solid line represents the estimated cumulative incidence of mortality and the shaded area represents the 95% CI.

Figure 3

Cox model for factors associated with in-hospital mortality in patients with COVID-19 supported with ECMO BMI=body-mass index. ECMO=extracorporeal membrane oxygenation. PaCO₂=partial pressure of arterial carbon dioxide. PaO₂:FiO₂=ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen. VA=venoarterial. VV=venovenous. VVA=venovenoaterial. *Dataset of 1031 patients; four observations were excluded due to having an initial cannulation mode that was not venovenous, venoarterial, or venovenoarterial.