Abstract and Introduction
Background: There are several reports of extracorporeal membrane oxygenation (ECMO) use in patients with coronavirus disease 2019 (COVID-19) who develop severe acute respiratory distress syndrome (ARDS). We conducted a systematic review and meta-analysis to guide clinical decision-making and future research.
Methods: We searched MEDLINE, Embase, Cochrane and Scopus databases from 1 December 2019 to 10 January 2021 for observational studies or randomised clinical trials examining ECMO in adults with COVID-19 ARDS. We performed random-effects meta-analyses and meta-regression, assessed risk of bias using the Joanna Briggs Institute checklist and rated the certainty of evidence using the GRADE approach. Survival outcomes were presented as pooled proportions while continuous outcomes were presented as pooled means, both with corresponding 95% confidence intervals [CIs]. The primary outcome was in-hospital mortality. Secondary outcomes were duration of ECMO therapy and mechanical ventilation, weaning rate from ECMO and complications during ECMO.
Results: We included twenty-two observational studies with 1896 patients in the meta-analysis. Venovenous ECMO was the predominant mode used (98.6%). The pooled in-hospital mortality in COVID-19 patients (22 studies, 1896 patients) supported with ECMO was 37.1% (95% CI 32.3–42.0%, high certainty). Pooled mortality in the venovenous ECMO group was 35.7% (95% CI 30.7–40.7%, high certainty). Meta-regression found that age and ECMO duration were associated with increased mortality. Duration of ECMO support (18 studies, 1844 patients) was 15.1 days (95% CI 13.4–18.7). Weaning from ECMO (17 studies, 1412 patients) was accomplished in 67.6% (95% CI 50.5–82.7%) of patients. There were a total of 1583 ECMO complications reported (18 studies, 1721 patients) and renal complications were the most common.
Conclusion: The majority of patients received venovenous ECMO support for COVID-19-related ARDS. In-hospital mortality in patients receiving ECMO support for COVID-19 was 37.1% during the first year of the pandemic, similar to those with non-COVID-19-related ARDS. Increasing age was a risk factor for death. Venovenous ECMO appears to be an effective intervention in selected patients with COVID-19-related ARDS.
The use of extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) during outbreaks of emerging infections was previously reported during the 2009 influenza A(H1N1) pandemic, as well as the Middle East respiratory syndrome coronavirus (MERS-CoV) outbreaks.[1–4] More recently, there are reports on the use of ECMO in patients with coronavirus disease 2019 (COVID-19), who develop severe ARDS.[5,6] The Extracorporeal Life Support Organisation (ELSO), the World Health Organization and the Surviving Sepsis Campaign (SSC) Guidelines recommend considering ECMO, in specialised centres, for patients with COVID-19 who develop severe ARDS. In addition, venovenous (VV) ECMO is recommended in selected patients who develop hypoxaemia that is refractory to optimal ventilator management and prone positioning, depending on the availability of resources.[7–11]
Initial case reports and case series on the use of ECMO for COVID-19-related ARDS were disappointing and raised concerns regarding ECMO use in this patient population.[12,13] However, several reports of ECMO use have subsequently emerged and have reported considerably better outcomes.[5,6,14,15] The first update of SSC guidelines published recently, suggested that ECMO should be considered only for carefully selected patients with COVID-19 and severe ARDS, with a weak strength of recommendation. Given the resource implications of providing ECMO in a pandemic and variability in the reported outcomes, we performed a systematic review of the literature to summarise outcome data during the first year of the pandemic and identify risk factors for an unfavourable outcomes in order to guide clinical decision-making and further research.
Crit Care. 2021;25(211) © 2021 BioMed Central, Ltd.
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