Paediatric extracorporeal priming procedures: does low temperature priming promote histamine release?

Abstract

We have recently reported pathologically elevated plasma histamine levels in adult patients undergoing cardiac surgery throughout the perioperative period. We have found markedly higher histamine levels in paediatric practice. The priming volume of the smallest extracorporeal systems is invariably greater than the circulating blood volume of neonates and infants, necessitating the use of stored donor blood in the initial priming procedure. In 40 paediatric cases, arbitrarily selected, sampling from the arterial port of the oxygenator prior to the initiation of bypass revealed massively elevated plasma histamine levels (>30ng/ml) in those extracorporeal circuits in which the priming volume was smallest and the priming temperature lowest - at 10-12°C. It is clear that the use of donor blood (in this series less than five days old) may contribute to the delivery of histamine into the paediatric patient's circulation at the onset of cardiopulmonary bypass and that the priming temperature may play a role.