Hybrid Respiratory Dialysis for Ultra-Low Blood-Flow Extracorporeal CO2 Removal

Extracorporeal carbon dioxide removal (ECCO2R) has emerged as a promising therapeutic avenue to address the challenges of CO2 accumulation during chronic obstructive pulmonary disease (COPD) exacerbations. Current COPD exacerbation interventions rely on invasive mechanical ventilation to support respiration, which can rapidly induce diaphragmatic atrophy and frequently leaves patients indefinitely reliant on a ventilator. Extracorporeal carbon dioxide removal could be a suitable modality to stabilize these critically ill patients; however, current implementations rely on either purely bicarbonate dialysis, which does not address acidemia, or a gas exchanger, which necessitates high blood flow rates. Herein, we describe a custom hybrid system for combined bicarbonate and gaseous CO2 elimination, achieving 123 ± 4 ml/min CO2 removal with direct pH adjustment at blood flow rates of 250 ml/min. This is achieved through the combination of 101 ± 2 ml/min bicarbonate removal from a dialysis methodology and 21 ± 2 ml/min CO2 removal across a novel, custom-built gas exchange device. Hence, this system is for COPD patients with hypercapnic respiratory failure across the dynamic respiratory demands of an exacerbation event. This amalgamation not only amplifies CO2 removal rates but also enables a less invasive therapeutic approach.