Cytokine and S100B levels in paediatric patients undergoing corrective cardiac surgery with or without total circulatory arrest

Objectives: Neurological damage following cardiopulmonary bypass (CPB) is d ifficult to objectively evaluate in infants. In adults, serum elevations of astroglial S100B correlate with proven brain injury independent of operati ve temperature. The deleterious effects of inflammatory cytokines, generate d during CPB, on the brain have not been studied in infants using S100B as a marker for cerebral injury. Methods: Twelve neonates, weighing 3.3 +/- 0. 2 kg (total circulatory arrest group (TCA)) and 12 infants weighing 7.0 +/- 1.0 kg (cardiopulmonary bypass group (CPB)) underwent corrective cardiac s urgery for various pathologies. Serial blood samples on induction, at the e nd of CPB, 30 min, 2 h and 24 h after the administration of protamine, were taken. The resultant plasma was frozen to -80 degrees C and stored for bat ch analysis. Cytokines were measured using ELISAs and S100B using a luminom etric assay. Results: The TCA group were younger and experienced a longer p erfusion time than the CPB group (137 +/- 8 vs. 113 +/- 7, P = 0.04). The m ean TCA time was 23 +/- 4 min. The TCA group had significantly higher level s of IL-6 (P = 0.001), IL-8 (P = 0.005)and S100B (P = 0.002) at 24 h. C5b-9 levels were significantly lower in the TCA group. end of CPB (P = 0.001), 30 min (P < 0.001), 2 h (P = 0.002). There was a weak, but significant corr elation between IL-6 levels at the end of CPB and S100B levels 2 h later (r = 0.55, P = 0.03). Long extubation times were associated with high 24-h S1 00B levels (r = 0.52, P = 0.01). Conclusions: (1) The TCA group have prolon ged rises of IL-6, IL-8 and S100B. (2) The TCA group generates significantl y lower complement. (3) Astroglial injury, seen after surgery, may, in part , be cytokine mediated. (C) 1999 Elsevier Science B.V. All rights reserved.