CYTOKINE PRODUCTION AND HEMOFILTRATION IN CHILDREN UNDERGOING CARDIOPULMONARY BYPASS

Multiorgan dysfunction still occurs after cardiopulmonary bypass and r emains a major cause of morbidity and mortality, especially in the ped iatric age group. This is consequent upon the so-called systemic infla mmatory response to bypass with an increase in inflammatory mediators. Hemofiltration may be able to attenuate the effects of this response by elimination of some or all of these mediators. We undertook a prosp ective, randomized study to investigate the effect of hemofiltration o n plasma levels of the cytokines tumor necrosis factor alpha, interleu kin-8,land interleukin 6 in 18 infants and children undergoing deep hy pothermic bypass. Serial plasma samples were taken before, during, and after bypass. Assay of the plasma samples revealed presence of the cy tokines in a number of subjects in both groups, in some cases before o peration. There were significant reductions in levels of tumor necrosi s factor after hemofiltration, with no reduction noted in the group no t undergoing hemofiltration. A similar difference (p<0.05) was detecte d in the levels of interleukin-6 between the two groups after bypass, although this was largely due to changes in 2 subjects. Interleukin-8 was detected in a small number of subjects insufficient for statistica l analysis, but with higher values in the group undergoing hemofiltrat ion. We conclude that hemofiltration has the potential to remove cytok ines from the circulation, with consequent beneficial effects.