Comparison of Pumps and Oxygenators With Pulsatile and Nonpulsatile Modes in an Infant Cardiopulmonary Bypass Model

Abstract

As the evidence mounts in favor of pulsatile perfusion during CPB, it is necessary to investigate the effect of circuit components on the quality of pulsatility delivered throughout the circuit. We compared two bloodpumps, the Jostra HL-20 heart-lung machine and the MEDOS DELTASTREAM DP1 Bloodpump, and two oxygenators, the Capiox Baby RX05 and the MEDOS HILITE 800LT, in terms of mean arterial pressure, energy equivalent pressure, surplus hemodynamic energy, total hemodynamic energy, and pressure drop over the oxygenators using a blood analog. The pumps and oxygenators were combined in unique circuits and tested in nonpulsatile and pulsatile modes, at two flow rates (500 and 800 mL/min), and three rotational speed differentials when using the MEDOS DELTASTREAM DP1 Bloodpump for 144 trials in total. The Jostra Roller pump produced some pulsatility in nonpulsatile mode and better pulsatility in pulsatile mode than the MEDOS DP1 Bloodpump at a rotational speed differential of 2500 rpm, but not at 3500 or 4500 rpm. The MEDOS DP1 Bloodpump produced almost no pulsatility in nonpulsatile mode. Pressure drops over the Capiox Baby RX05 were markedly higher, at 92.5 +/- 0.4 mm Hg with the MEDOS DP1 Bloodpump at 800 mL/min and 4500 rpm in pulsatile mode, than those of the MEDOS HILITE 800LT oxygenator, which was 67.0 +/- 0.1 mm Hg at the same settings. These results suggest that careful selection of each circuit component, based on the individual clinical case and component specifics, are necessary to achieve the best quality of pulsatility.