Introduction: The aim of this study was to investigate the kinetic patterns of detectable S-100, a specific cerebral glial protein, in infants undergoing corrective cardiac surgery by means of full flow cardiopulmonary bypass (CPB) Methods: 40 newborns and infants below the age of 8 months undergoing corrective cardiac surgery by means of full flow CPB(120-150 ml/Kg/BW) with moderate hypothermia (24+6 C°) and alpha-stat strategy were enrolled in this study. Blood samples were collected before, immediately after CPB and then 2, 24, 48, and 72 h postoperatively. The S-100 protein serum concentrations were analysed using a commercially available two-site immunradiometric assay kit (Sangtec Medical AB, Bromma-Sweden).Results: In 36 patients without major hemodynamic instability or detectable neurologic abnormalities a characteristic pattern of increased S-100 serum levels was observed with a significantly (p<0.001) elevation during the first 24 postoperative hours, reaching preoperative values within 48 hours postoperatively. An abnormal pattern with significantly higher serum levels were found in 4 patients with seizures (n=1), intraventricular hemorrhage grade II (n=1), and two infants with low cardiac output (n=2). Significant inverse correlation was found between the peak value of S-100 and the weight (r=-0.51, p=0.02), minimal temperature (r=-0.54, p0.013)

Conclusion: serial determination of serum S-100 protein may provide further information on the degree of occured cerebral injury associated with cardiac surgery.

*Supported by Sangtec Medical AB, Bromma-Sweden