Experimental Biology 2010: Hemolytic And Thrombogenic Characteristics Of Ecmo Systems At Simulated Flow Rate For Neonates.

Purpose of Study: Modern centrifugal pumps/hollow-fiber oxygenator systems for extracorpeal membrane oxygenation (ECMO) have advantages such as less priming volume, ability to place the pump at any level in relation to the patient, and no pressure generation that can lead to tubing rupture as compared to the more commonly used roller-head/silicone membrane systems. Adoption of the centrifugal pump/hollow fiber oxygenator system has been slow due to past evidence of severe hemolysis leading to subsequent renal failure and mortality. Another complication of the neonate on ECMO is intracranial hemorrhage, which can be caused by platelet dysfunction. Little data exists comparing the modern centrifugal pump/hollow-fiber oxygenator system vs. roller-head/silicone membrane system for their hemolytic and platelet function at low flow rates consistent with neonatal ECMO. The purpose of this research is to choose a system that is optimal for neonatal care.

Methods Used: In a pilot analysis, two newer components (Jostra Rotaflow pump and Quadrox-D oxygenator, Maquet, Wayne, NJ) were compared to the standard roller-head pump (Jostra, Maquet, Wayne, NJ) and silicone membrane oxygenator (Medtronic, Minneapolis, MN) in a simulated in vitro ECMO circuit circulating whole swine blood at 300 ml/min. Four circuit combinations were examined for hemolysis and platelet aggregation during 6 hrs of continuous use. Hemolysis was measured by plasma free hemoglobin (fPH) using a spectrophotometer. Platelet aggregation was measured using flow cytometry.

Summary of Results: All of the ECMO systems created fPH at a similar rate as compared to the static. There was no difference in the mean NIH for the centrifugal/hollow-fiber oxygenator and the roller/silicone systems, 0.0024±.0007 (g/100L) versus 0.0024±0.0018 (g/100L), respectively. Preliminary results may show that ECMO systems with a hollow-fiber oxygenator have greater platelet aggregation compared to systems with a silicone membrane oxygenator.

Conclusions: In a low-flow environment, centrifugal/hollow-fiber and roller-head/silicone membrane systems have similar mean index of hemolysis. Further study to confirm these preliminary results and correlate to patient care is warranted.