Blood S-100 protein concentration in children undergoing cardiac surgery

Objectives: To investigate plasma levels of the pp isomer of S-100 protein and to assess the relationship between post-cardiopulmonary bypass (CPB) le vels of this marker and a variety of perioperative and patient factors in c hildren undergoing cardiac surgery. Design: Prospective study. Setting: University hospital. Participants: Twenty-five children. Interventions: Blood samples (2 mL) for S-100 determinations were collected after the induction of anesthesia, 30 minutes after aortic cross-clamping, 1 hour after the termination of CPB, and 5 and 24 hours after the operatio n. Electroencephalogram activity was recorded, and neurologic examination w as performed on all children 1 day before and 10 days after the operation. Lowest values of nasopharyngeal temperature, mean arterial pressure, arteri al carbon dioxide tension (PaCO2), pH, and hematocrit during CPB were recor ded. Measurements and Main Results: The overall change in S-100 during the study period was found to be statistically significant (p < 0.0001). correlation between <Delta>S-100 and age (r = -0.45; p = 0.04), body surface area (r = -0.63; p 0.002), nasopharyngeal temperature (r = -0.55; p = 0.01), and PaC O2 (r = -0.55; p = 0.009) was statistically significant in infants and chil dren. Multivariate regression analysis indicated significant effects of PaC O2 and body surface area on DeltaS-100 levels and area under the curve valu es. Conclusion: In contrast to newborns, infants and older children showed prom inent increases in S-100 protein concentration. Lack of pathologic electroe ncephalogram findings and neurologic signs in the postoperative period prec ludes the clinical use of S-100 protein concentration as a sensitive marker of cerebral injury. Copyright (C) 2001 by W.B. Saunders Company.