Physiologic Improvement in Respiratory Acidosis Using Extracorporeal Co 2 Removal 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 Co2 removal can facilitate lung-protective ventilation and avoid the adverse effects of severe respiratory acidosis. The objective was to evaluate the efficacy of extracorporeal Co2 removal 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 Co2 removal. 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 Co2 removal 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 Paco2 from 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 Pco2 in 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 Co2 removal using the Hemolung Respiratory Assist System to improve respiratory acidosis in patients with severe hypercapnic respiratory failure due to coronavirus disease 2019.