Oxygenator deterioration in a standardized in vitro setup: pressure drop, CT-based clot burden, and hemolysis

Abstract

Oxygenator deterioration during ECMO is a multifactorial process associated with deposit formation, an increase in hydraulic resistance, impaired gas exchange, and blood damage. To enable controlled in vitro assessment, a standardized continuous dual-loop test circuit using a Terumo CAPIOX FX05 oxygenator and heparinanticoagulated porcine whole blood was established. Progressive obstruction was induced by hourly administration of hollow glass microspheres. Functional deterioration was assessed by intermittent blood sampling and continuous monitoring of hydraulic and blood-gas-related parameters, while post hoc computed tomography (CT) and MATLABbased analysis were used to estimate CT-derived suspected clot burden and spatial distribution. Four experimental runs were analyzed. Pressure drop increased from (61 . 82±9 . 55)mmHg at baseline to (232 . 55±6 . 01)mmHg before run termination, and hemolysis index rose from (0 . 07 ± 0 . 03)% to (1 . 51 ± 0 . 58)%. CT indicated preferential central deposit accumulation with lower burden near the outlet. Estimated deposit volumes ranging from 14 . 27mL to 48 . 99mL. The setup enabled controlled induction and multimodal characterization of progressive oxygenator deterioration in a standardized in vitro model.