In Vitro Comparison of the Delivery of Gaseous Microemboli and Hemodynamic Energy for a Diagonal and a Roller Pump During Simulated Infantile Cardiopulmonary Bypass Procedures

Abstract

Cardiopulmonary bypass (CPB) is used for a variety of procedures in pediatric patients. Flow settings of the CPB pump have dramatic effects on patient outcome, and gaseous microemboli delivery within the CPB circuit has been linked to neurological complications. To ensure the ongoing improvement of pediatric CPB, consistent evaluation and improvement of the equipment is necessary. In this study we analyze the Jostra HL-20 roller pump (Jostra USA, Austin, TX, USA) and a Medos Deltastream DP3 diagonal pump (MEDOS Medizintechnik AG, Stolberg, Germany) which has not yet received Food and Drug Administration approval. An infant CPB model with heparinized human blood is used to quantify the gaseous microemboli delivery (via an Emboli Detection and Classification Quantifier), as well as the hemodynamic energy delivered under flow rates of 400, 800, and 1200 mL/min. Results show that at most flow settings the DP3 delivers fewer microemboli than the Jostra roller pump at the pre-oxygenator site, with an exception at 1200 mL/min under pulsatile mode. The total volume and the number of gaseous microemboli greater than 40 μm in diameter were lower in the DP3 group. The HL-20 exhibits less stolen blood flow (except at 1200 mL/min) and oxygenator pressure drops in both pulsatile and nonpulsatile mode. Additionally, under pulsatile flow the DP3 delivers greater surplus hemodynamic energy. Both pumps produce relatively few microemboli and deliver adequate hemodynamic energy to the pseudo-patient, with the DP3 performing slightly better under most flow settings.