S100B blood levels correlate with rewarming time and cerebral Doppler in pediatric open heart surgery.

BACKGROUND

Brain hyperthermia, accompanying the rewarming phase of cardiopulmonary bypass (CPB), has been involved in the genesis of postoperative brain damage. Blood S100B levels are emerging as a marker of brain distress, and could offer a reliable monitoring tool at different times during and after open heart surgery.

METHODS

Thirty-two patients undergoing repair of congenital heart disease with CPB and deep hypothermic circulatory arrest (DHCA) were monitored by S100B blood levels and middle cerebral artery Doppler velocimetry pulsatility index (MCA PI) before, during, and after surgical procedure at five predetermined time-points.

RESULTS

Both S100B and MCA PI significantly increased, MCA PI values exhibiting a peak at the end of surgery time-point (p > 0.05), while S100B blood levels were increased at the end of CPB (p < 0.05). Multivariate analysis, with S100B levels measured at the end of CPB as dependent variable, showed a positive significant correlation with MCA PI (p = 0.04), with the CPB and the rewarming duration (p = 0.03 and p = 0.009, respectively).

CONCLUSIONS

The present results show a significant correlation between a biochemical marker of brain damage and an index of increased cerebrovascular resistance, with higher levels during the rewarming CPB phase in pediatric open heart surgery.