Extracorporeal Carbon Dioxide Removal to De-escalate Venovenous Extracorporeal Membrane Oxygenation in Severe COVID-19 Acute Respiratory Distress Syndrome

Abstract

Objectives: In a subset of patients with COVID-19 acute respiratory distress syndrome (ARDS), there is a need for extracorporeal membrane oxygenation (ECMO) for pulmonary support. The primary extracorporeal support tool for severe COVID-19 ARDS is venovenous (VV) ECMO; however, after hypoxemic respiratory failure resolves, many patients experience refractory residual hypercarbic respiratory failure. Extracorporeal carbon dioxide removal (ECCO₂R) for isolated hypercarbic type II respiratory failure can be used in select cases to deescalate patients from VV ECMO while the lung recovers the ability to exchange CO₂. The objective of this study was to describe the authors' experience in using ECCO₂R as a bridge from VV ECMO.

Design: Hemolung Respiratory Assist System (RAS) is a commercially available (ECCO₂R) device, and the United States Food and Drug Administration accelerated its use under its Emergency Use Authorization for the treatment of refractory hypercarbic respiratory failure in COVID-19-induced ARDS. This created an environment in which selected and targeted mechanical circulatory support therapy for refractory hypercarbic respiratory failure could be addressed. This retrospective study describes the application of Hemolung RAS as a VV ECMO deescalation platform to treat refractory hypercarbic respiratory failure after the resolution of hypoxemic COVID-19 ARDS.

Setting: A quaternary-care academic medical center, single institution.

Participants: Patients with refractory hypercarbic respiratory failure after COVID-19 ARDS who were previously supported with VV ECMO.

Measurements and main results: Twenty-one patients were placed on ECCO₂R after VV ECMO for COVID-19 ARDS. Seventeen patients successfully were transitioned to ECCO₂R and then decannulated; 3 patients required reescalation to VV ECMO secondary to hypercapnic respiratory failure, and 1 patient died while on ECCO₂R. Five (23.8%) of the 21 patients were transitioned off of VV ECMO to ECCO₂R, with a compliance of <20 (mL/cmH₂O). Of these patients, 3 with low compliance were reescalated to VV ECMO.

Conclusions: Extracorporeal carbon dioxide removal can be used to continue supportive methods for patients with refractory type 2 hypercarbic respiratory failure after COVID-19 ARDS for patients previously on VV ECMO. Patients with low compliance have a higher rate of reescalation to VV ECMO.