Physiologic Improvement in Respiratory Acidosis Using Extracorporeal C o ₂Removal With Hemolung Respiratory Assist System in the Management of Severe Respiratory Failure From Coronavirus Disease 2019

Objectives: About 15% of hospitalized coronavirus disease 2019 patients require ICU admission, and most (80%) of these require invasive mechanical ventilation. Lung-protective ventilation in coronavirus disease 2019 acute respiratory failure may result in severe respiratory acidosis without significant hypoxemia. Low-flow extracorporeal Co₂removal can facilitate lung-protective ventilation and avoid the adverse effects of severe respiratory acidosis. The objective was to evaluate the efficacy of extracorporeal Co₂removal using the Hemolung Respiratory Assist System in correcting severe respiratory acidosis in mechanically ventilated coronavirus disease 2019 patients with severe acute respiratory failure. Design: Retrospective cohort analysis of patients with coronavirus disease 2019 mechanically ventilated with severe hypercapnia and respiratory acidosis and treated with low-flow extracorporeal Co₂removal. Setting: Eight tertiary ICUs in the United States. Patients: Adult patients supported with the Hemolung Respiratory Assist System from March 1, to September 30, 2020. Interventions: Extracorporeal Co₂removal with Hemolung Respiratory Assist System under a Food and Drug Administration emergency use authorization for coronavirus disease 2019. Measurements and Main Results: The primary outcome was improvement in pH and Paco₂from baseline. Secondary outcomes included survival to decannulation, mortality, time on ventilator, and adverse events. Thirty-one patients were treated with Hemolung Respiratory Assist System with significant improvement in pH and Pco₂in this cohort. Two patients experienced complications that prevented treatment. Of the 29 treated patients, 58% survived to 48 hours post treatment and 38% to hospital discharge. No difference in age or comorbidities were noted between survivors and nonsurvivors. There was significant improvement in pH (7.24 ± 0.12 to 7.35 ± 0.07; p < 0.0001) and Paco₂(79 ± 23 to 58 ± 14; p < 0.0001) from baseline to 24 hours. Conclusions: In this retrospective case series of 29 patients, we have demonstrated efficacy of extracorporeal Co₂removal using the Hemolung Respiratory Assist System to improve respiratory acidosis in patients with severe hypercapnic respiratory failure due to coronavirus disease 2019.