Extracorporeal life support systems: alternative vs. conventional circuits

Emerging technologies and practices for pediatric and neonatal extracorporeal life support (ECLS) are promising. This experiment sought to compare the Medtronic 0800 silicon rubber membrane oxygenator to the Quadrox-iD Pediatric oxygenator in the conventional roller pump circuit, as well as comparing the conventional circuit to an alternative circuit. Three circuits were set up in the experiment. Two conventional roller pump circuits were used to compare the two oxygenators and an alternative circuit consisting of the Quadrox-iD Pediatric oxygenator and Maquet Rotaflow centrifugal pump system was used to identify differences between circuits. All three circuits were primed with Lactated Ringers' solution and human blood, with an hematocrit of 40%. Testing occurred at flow rates of 250, 500, and 750 ml/min at 37 degrees C for mean arterial line pressures of 60, 80, and 100 mmHg. The results of the experiment showed lower pressure drops and greater retention of total hemodynamic energy (THE) across the Quadrox-iD Pediatric oxygenator compared to the Medtronic 0800 oxygenator. Furthermore, the centrifugal pump used in the alternative circuit showed no back flow at flow rates as low as 250 ml/min while, on the other hand, rpm levels were kept below 2200 for flow rates as high as 750 ml/min. Findings support the usage of the Quadrox-iD Pediatric oxygenator in a circuit utilizing the Maquet Rotaflow centrifugal pump system due to lower pressure drops and greater percentage of THE retained across the circuit. Additional advantages of the alternative circuit include rapid set-up time, easy transport, lower priming volumes, and no gravity-dependent venous drainage system so that it can be situated in close proximity to and at the level of the patient.