Evaluation of centrifugal blood pumps in term of hemodynamic performance using simulated neonatal and pediatric ECMO circuits

Abstract

The objective of this translational study was to evaluate the FDA-approved PediMag, CentriMag, and RotaFlow centrifugal blood pumps in terms of hemodynamic performance using simulated neonatal and pediatric extracorporeal membrane oxygenation (ECMO) circuits with different sizes of arterial and venous cannulae. Cost of disposable pump heads was another important variable for this particular study. The experimental circuit was composed of one of the centrifugal pump heads, a polymethylpentene membrane oxygenator, neonatal and pediatric arterial/venous cannulae, and 1/4-inch ID tubing. Circuits were primed with lactated Ringer's solution and packed human red blood cells (hematocrit 35%). Trials were conducted at 36°C using the three pump heads and different cannulae (arterial/venous cannulae: 8Fr/18Fr, 10Fr/20Fr, and 12Fr/22Fr) at various flow rates (200-2400 mL/min, 200 mL/min increments) and rotational speeds. Pseudo patient pressure was 60 mmHg. Real-time pressure and flow data were recorded for analysis. The RotaFlow pump had a higher pressure head and flow range compared with the PediMag and CentriMag pumps at the same rotational speed and identical experimental settings (P<0.001). The PediMag pump had lower flow output than others (P<0.001). Small-caliber arterial cannulae and higher flow rates predictably created higher circuit pressures and pressure drops. There was no significant difference in hemodynamic energy delivered to the pseudo patient with each of the three pumps. The arterial cannula had the highest pressure drop and hemodynamic energy loss in the circuit when compared to the oxygenator and arterial tubing. The RotaFlow centrifugal pump had a significantly better hemodynamic performance when compared to the PediMag and CentriMag blood pumps at identical experimental conditions in simulated neonatal and pediatric ECMO settings. In addition, the cost of the RotaFlow pump head ($400) is 20 to 30-fold less than the other centrifugal pumps [CentriMag ($12000) or PediMag ($8000)] that were evaluated in this translational study.