Prone position in severe hypoxemia in patients with covid-19 during venovenous ECMO, does the number of cycles matter?

Abstract

Extracorporeal membrane oxygenation (ECMO) support has been known to be beneficial in cases of severe Adult Respiratory Distress Syndrome (ARDS). The increase in such cases results in an increase in scenarios of severe hypoxemia even during an ECMO run. The purpose of this study was to evaluate the benefit of the prone position (PP) in an analytical observational retrospective cohort study. The study included adult patients with ARDS, caused as a result of SARS-CoV-2, undergoing PP during ECMO support in the period from 2020 to 2021. Thirty-five patients were placed in PP with an average of 3.6 cycles per patient. The group of patients undergoing >3 PP cycles had a significant improvement in oxygenation during PP, 𝑃𝑎𝑂2 (60.13 vs. 66.15, mmHg p = 0.0065) and 𝑃𝑎𝑂2⁄𝐹𝑖𝑂2 (136 vs. 155, p = 0.0026). After adjusting for confounding variables (age, RESP score, and days from the start of ECMO and the first cycle of PP), the group with >3 cycles showed a hazard ratio of 0.2 (95% confidence interval, 0.051–0.78; p = 0.02). The study outcomes confirmed the benefits of PP as a strategy against severe hypoxemia in ECMO, and evaluated variables such as the number of cycles, which may be associated with improved survival in this subgroup of critically ill patients.