A novel pump-driven veno-venous gas exchange system during extracorporeal CO.sub.2-removal

Purpose Pump-driven veno-venous extracorporeal CO.sub.2-removal (ECCO.sub.2-R) increasingly takes root in hypercapnic lung failure to minimize ventilation invasiveness or to avoid intubation. A recently developed device (iLA activve.sup.®, Novalung, Germany) allows effective decarboxylation via a 22 French double lumen cannula. To assess determinants of gas exchange, we prospectively evaluated the performance of ECCO.sub.2-R in ten patients receiving iLA activve.sup.® due to hypercapnic respiratory failure. Methods Sweep gas flow was increased in steps from 1 to 14 L/min at constant blood flow (phase 1). Similarly, blood flow was gradually increased at constant sweep gas flow (phase 2). At each step gas transfer via the membrane as well as arterial blood gas samples were analyzed. Results During phase 1, we observed a significant increase in CO.sub.2 transfer together with a decrease in PaCO.sub.2 levels from a median of 66 mmHg (range 46-85) to 49 (31-65) mmHg from 1 to 14 L/min sweep gas flow (p < 0.0001), while arterial oxygenation deteriorated with high sweep gas flow rates. During phase 2, oxygen transfer significantly increased leading to an increase in PaO.sub.2 from 67 (49-87) at 0.5 L/min to 117 (66-305) mmHg at 2.0 L/min (p < 0.0001). Higher blood flows also significantly enhanced decarboxylation (p < 0.0001). Conclusions Increasing sweep gas flow results in effective CO.sub.2-removal, which can be further reinforced by raising blood flow. The clinically relevant oxygenation effect in this setting could broaden the range of indications of the system and help to set up an individually tailored configuration.
Author(s): Alexander Hermann [sup.1], Katharina Riss [sup.1], Peter Schellongowski [sup.1], Andja Bojic [sup.1], Philipp Wohlfarth [sup.1], Oliver Robak [sup.1], Wolfgang R. Sperr [sup.1], Thomas Staudinger [sup.1] Author Affiliations: (1) grid.22937.3d, [...]