Echocardiography Before Extracorporeal Membrane Oxygenation in Refractory Respiratory Failure: SARS-CoV-2 Infection Versus Other Etiologies

Objectives: The study authors hypothesized that in patients with SARS-CoV-2, COVID-19-related refractory respiratory failure requiring extracorporeal membrane oxygenation (ECMO) support echocardiographic findings (just before ECMO implantation) would be different from those observed in patients with refractory respiratory failure from different etiologies.

Design: A single-center observational study.

Setting: At an intensive care unit (ICU).

Participants: A total of 61 consecutive patients with refractory COVID-19-related respiratory failure (COVID-19 series) and 74 patients with refractory acute respiratory disease syndrome from other etiologies (no COVID-19 series), all needing ECMO support.

Interventions: Echocardiogram pre-ECMO.

Measurements and main results: Right ventricle dilatation and dysfunction were defined in the presence of the RV end-diastolic area and/or left ventricle end-diastolic area (LVEDA >0.6 and tricuspid annular plane systolic excursion [TAPSE] <15 mm. Patients in the COVID-19 series showed a higher body mass index (p < 0.001) and a lower Sequential Organ Failure Assessment score (p = 0.002). In-ICU mortality rates were comparable between the 2 subgroups. Echocardiograms performed in all patients before ECMO implantation revealed an incidence of RV dilatation that was higher in patients in the COVID-19 series (p < 0.001), and they also showed higher values of systolic pulmonary artery pressure (sPAP) (p < 0.001) and lower TAPSE and/or sPAP (p < 0.001). The multivariate logistic regression analysis showed that COVID-19-related respiratory failure was not associated with early mortality. The presence of RV dilatation and the uncoupling of RV function and pulmonary circulation were associated independently with COVID-19 respiratory failure.

Conclusions: The presence of RV dilatation and an altered coupling between RVe function and pulmonary vasculature (as indicated by TAPSE and/or sPAP) are associated strictly with COVID-19-related refractory respiratory failure needing ECMO support.