ABSTRACT
Objectives Refractory hypoxemia can occur in patients with acute respiratory distress syndrome (ARDS) from Coronavirus disease 2019 (COVID-19) despite support with venovenous extracorporeal membrane oxygenation (VV-ECMO). Parallel ECMO circuits can be used to increase physiologic support. We report our clinical experience using ECMO circuits in parallel for select patients with persistent severe hypoxemia despite the use of a single ECMO circuit. Methods We performed a retrospective cohort study of all patients with COVID-19 related ARDS receiving VV-ECMO who received an additional circuit in parallel at Vanderbilt University Medical Center between March 1, 2020 and March 1, 2022. We report demographics, clinical characteristics including ECMO settings, mechanical ventilator settings, use of adjunctive therapies, and arterial blood gas results after initial cannulation, before and after receipt of a second ECMO circuit in parallel, and prior to removal of the circuit in parallel, and outcomes. Results Of 84 patients with COVID-19 who received VV-ECMO during the study period, 22 patients (26.2%) received a circuit in parallel. The median time on ECMO was 40.0 days (IQR, 31.6-53.1 days), of which 19.0 days (IQR, 13.0-33.0 days) were spent on a circuit in parallel. Of the 22 patients who received a circuit in parallel, 16 (72.7%) survived to hospital discharge and 6 (27.3%) died before discharge. Conclusions In select patients, addition of an ECMO circuit in parallel can increase ECMO blood flow and improve oxygenation while allowing for lung-protective mechanical ventilation and excellent outcomes.