Short Term Performance Evaluation of a Perfluorocopolymer Coated Gas Exchanger for Arteriovenous CO₂ Removal

A new perfluorocopolymer coating for micropore hollow fiber gas exchangers was developed to improve gas exchange, reduce plasma leakage, and reduce blood-surface interactions. The present authors evaluated gas exchanger performance using this new coating in a prospective, randomized, controlled, unblinded, large animal model of CO₂ retention. Adult sheep (30-40 kg), under general anesthesia, underwent cannulation of the carotid artery (12 F) and jugular vein (14 F). The perfluorocopolymer coated (n = 5) and uncoated (n = 5) gas exchangers were attached to an arteriovenous CO₂ removal (AVCO₂R) circuit. Blood gases, CO₂ removal, and hemodynamics were monitored throughout the 6 hour study. Average CO₂ removal was 107.6 ± 15.6 ml/min (coated) vs. 93.0 ± 13.9 ml/min (uncoated; p < 0.01). PaCO₂ and CO₂ removal for both coated and uncoated did not deteriorate significantly over the study. Average AVCO₂R blood flow was 1,130 ± 25 ml/min (coated) versus 1,101 ± 79 ml/min (uncoated; p = not significant). Likewise, cardiac output and AVCO₂R blood flow did not change over the duration of the study. No significant differences in the pressure gradient or resistance between devices (coated, 6.89 ± 1.14 mm Hg/L/min; uncoated, 6.42 ± 0.23 mm Hg/L/min) was noted. The authors concluded that the new perfluorocopolymer coated gas exchanger improved CO₂ removal without compromising hemodynamics in an acute performance evaluation.