S100 and S100β: biomarkers of cerebral damage in cardiac surgery with or without the use of cardiopulmonary bypass

Objective: The present study is to describe the clinical impact of S100 and S100 beta for the evaluation of cerebral damage in cardiac surgery with or without the use of cardiopulmonary bypass (CPB). Methods: Quantitative results of S100 and S100 beta reported in the literature of the year range 1990-2014 were collected, screened and analyzed. Results: Cerebrospinal fluid and serum S100 levels showed a same trend reaching a peak at the end of CPB. The cerebrospinal fluid/serum S100 ratio decreased during CPB, reached a nadir at 6 h after CPB and then increased and kept high untill 24 h after CPB. Serum S100 at the end of CPB was much higher in infant than in adults, and in on-pump than in off-pump coronary artery bypass patients. Delta S100 increased with age and CPB time but lack of statistical significances. Patients receiving an aorta replacement had a much higher Delta S100 than those receiving a congenital heart defect repair. Serum S100 beta reached a peak at the end of CPB, whereas cerebrospinal fluid S100 continued to increase and reached a peak at 6 h after CPB. The cerebrospinal fluid/serum S100 beta ratio decreased during CPB, increased at the end of CPB, peaked 1 h after CPB, and then decreased abruptly. The increase of serum S100 beta at the end of CPB was associated with type of operation, younger age, lower core temperature and cerebral damages. Delta S100 beta displayed a decreasing trend with age, type of operation, shortening of CPB duration, increasing core temperature, lessening severity of cerebral damage and the application of intervenes. Linear correlation analysis revealed that serum S100 beta concentration at the end of CPB correlated closely with CPB duration. Conclusion: S100 and S100 beta in cerebrospinal fluid can be more accurate than in the serum for the evaluations of cerebral damage in cardiac surgery. However, cerebrospinal fluid biopsies are limited. But serum S100 beta and Delta S100 beta seem to be more sensitive than serum S100 and Delta S100. The cerebral damage in cardiac surgery might be associated with younger age, lower core temperature and longer CPB duration during the operation. Effective intervenes with modified CPB circuit filters or oxygenators and supplemented anesthetic agents or priming components may alleviate the cerebral damage.