Purpose: Since the early 1970's, traditional extracorporeal membrane oxygenation (ECMO) circuits consisting of silicone membrane oxygenators and roller pumps have been standard in pediatric extracorporeal life support. Over the last decade newer smaller circuits employing polymethylpentene (PMP) hollow-fiber oxygenators and centrifugal pumps have been introduced with reportedly improved flow dynamics and hematologic profiles. The comparative efficacy of these newer circuits in children has not been convincingly shown.
Methods: We retrospectively reviewed our institutional experience with two circuit types in children. Prior to 2007, silicone oxygenators and roller pumps were used for infants and children requiring ECMO support. After 2007, the Quadrox-iD Pediatric and Adult (Maquet; Wayne, NJ) PMP oxygenators were introduced for infants and children less than or greater than 20kg, respectively. Centrifugal pumps consisting of either a CentriMag (Thoratec; Pleasanton, CA) or Rotaflow (Maquet; Wayne, NJ) pump have been used in all cardiac patients and in non-cardiac patients greater than 8 kg. Data on age, weight, diagnosis type, gender, ECMO duration, survival, patient or mechanical complications, and transfusion requirements were obtained. Multivariate logistic regression analyses and student t-tests were performed.
Results: At our institution, 221 children have been supported with ECMO between 2000-2011. 110 patients were supported for cardiac diagnoses and 111 for non-cardiac support. Median age at time of ECMO support was 0.1 months (range 0.03-264). Median weight was 3.69 kg (range 2.1-88). Median ECMO course length was 119 hours (range 5-879). There was no difference in patient complications, ECMO survival and hospital survival between the different circuit types. Mechanical complications were associated with the use of older circuits (p=0.022) and longer ECMO courses (p=0.011) adjusted for other variables obtained. Higher mean blood and platelet transfusions at 24 hours (p=0.02, p<0.0001) and 72 hours (p=0.05, p<0.0001) of support were found in older circuits compared to newer circuits [Table 1].
Conclusion: Newer pediatric ECMO circuits consisting of PMP hollow-fiber oxygenators and centrifugal pumps provide an attractive alternative to traditional silicone oxygenators and roller pumps due to a lower incidence of mechanical complications and less blood product requirements. Despite these advantages, our results suggest that newer circuits are equivalent on survival. Further study on optimizing these newer circuits is needed to improve patient outcome.