Extracorporeal Membrane Oxygenation Therapy for Critically Ill Coronavirus Disease 2019 Patients in Wuhan, China: A Retrospective Multicenter Cohort Study

Background: Currently, little in-depth evidence is known about the therapeutic considerations and the outcomes of extracorporeal membrane oxygenation (ECMO) therapy in coronavirus disease 2019 (COVID-19) patients. Methods: This retrospective multicenter cohort study included patients with COVID-19 and received ECMO therapy at seven designated hospitals in Wuhan, China. The patients were followed until April 30, 2020. The clinical characteristics, laboratory examinations, treatments, and outcomes were extracted from electronic medical records and compared between weaned and non-weaned ECMO patients. Logistic regression analyses were performed to identify the risk factors associated with unsuccessful ECMO weaning. Propensity score matching was used to match patients who received venovenous ECMO with those who received invasive mechanical ventilation (IMV)-only therapy. The primary endpoint, 60-day all-cause mortality after ICU admission during hospitalization, was compared using a mixed-effect Cox model. Findings: 88 patients received ECMO therapy were included in the descriptive study. Among them, 27 and 61 patients were and were not successfully weaned from ECMO, respectively. Additionally, 13, 11, and 61 patients were further weaned from IMV, discharged from hospital, or died during hospitalization, respectively. In the multivariate logistic regression analysis, a lymphocyte count ≤ 0·5 × 109/L and D-dimer concentration > 4 × the upper limit of normal at ICU admission, a peak PaCO2 > 60 mmHg at 24 hours before ECMO initiation, and no tracheotomy performed during the ICU stay were independently associated with lower odds of ECMO weaning. In the propensity score-matched analysis, the crude 60-day mortality rates were 67·1% in the ECMO group and 80·0% in the IMV group. A mixed-effect Cox model detected a lower hazard ratio for the primary endpoint in the ECMO group. Interpretation: Patients in Wuhan who received ECMO therapy had a relatively high mortality rate. This outcome may be largely attributable to resource-limited situations during the COVID-19 outbreak. In future, the presence of lymphocytopenia and higher D-dimer concentrations at ICU admission and hypercapnia at 24 hours before ECMO initiation could help to identify patients with a poor prognosis. Moreover, tracheotomy could facilitate weaning from ECMO. Despite the high mortality, ECMO was associated with improved outcomes relative to IMV-only therapy in critically ill COVID-19 patients. Funding Statement: This work was supported by grants from Emergent Key Projects for COVID-19 (NO. 2020kfyXGYJ091), the National Natural Science Foundation of China (NO. 81800256, 81873458, 81670050), and National Key Research and Development Program of China (2019YFC0121600). Declaration of Interests: The authors declare no competing interests for this study. Ethics Approval Statement: The institutional ethical committee of each participating hospital approved the study protocol and waived the requirement for informed patient consent.