Novel Strategies to Enhance the Efficiency of Extracorporeal CO2 Removal

Extracorporeal carbon dioxide removal (ECCO2R) is an extracorporeal lung support system aimed at removing carbon dioxide (CO2) from the blood through an artificial membrane lung. This technique has been primarily proposed as a treatment for acute respiratory distress syndrome, chronic obstructive pulmonary disease exacerbation, and acute asthma. However, despite showing clinical effectiveness, recent trials also detected an increased rate of adverse events, mainly hemorrhagic complications, in the population receiving ECCO2R, thus raising significant concerns about the safety of the treatment. Enhancement of CO2 removal efficiency has been proposed as a possible technological improvement required to overcome the actual limitations associated with the ECCO2R treatments. This chapter revisits the multiple strategies proposed to enhance ECCO2R, many of which are still undergoing preclinical evaluation. Some studies have focused on membrane lung design, others on increasing the CO2 gradient across the membrane lung, and others tried to remove blood CO2 as bicarbonate ions. However, research is still needed to improve the safety of the treatment before possible clinical application. Highly efficient ECCO2R systems may enable clinical effectiveness at low blood flow, thus permitting the combination of ECCO2R with regional anticoagulation and modular multiorgan support.