Iron overload in paediatrics undergoing cardiopulmonary bypass

Pathological changes in iron status are known to occur during bypass and wi ll be superimposed upon physiological abnormalities in iron distribution, c haracteristic of the neonatal period. We have sought to define the severity of iron overload in these patients. Plasma samples from 65 paediatric pati ents undergoing cardiopulmonary bypass (CPB) were analysed for non-haem iro n, total iron binding capacity, transferrin and bleomycin-detectable iron. Patients were divided into four age groups for analysis. Within each age gr oup, patients who were in iron overload at any time point were statisticall y compared to those who were not. The most significant changes in iron chem istry were seen in the plasma of neonates, with 25% in a state of plasma ir on overload. 18.5% of infants and 14.3% of children at 1-5 years were also in iron overload at some time point during CPB. No children over 5 years, h owever, went into iron overload. Increased iron saturation of transferrin e liminates its ability to bind reactive forms of iron and to act as an antio xidant. When transferrin is fully saturated with iron, reactive forms of ir on are present in the plasma which can stimulate iron-driven oxidative reac tions. Our data suggest that paediatric patients are at greater risk of iro n overload during CPB, and that some form of iron chelation therapy may be advantageous to decrease oxidative stress. (C) 2000 Published by Elsevier S cience B.V. All rights reserved.