Serum S100 protein as a marker of cerebral damage during cardiac surgery

The identification of a serum marker to assist in the diagnosis of cerebral injury after cardiac surgery is potentially useful. S100 protein is an ear ly marker of cerebral damage. It is released after cardiac surgery performe d under cardiopulmonary bypass (CPB). Its level is correlated with the dura tion of CPB, deep circulatory arrest and aortic cross-clamping. Increased l evels of S100 protein are correlated with the age of the patient and the nu mber of microemboli, especially during aortic cannulation. Perioperative ce rebral complications such as stroke, delayed awakening and confusion are as sociated with increased levels of S100 protein directly after bypass and fr om 15 to 48 h after it. In addition, increased levels of S100 protein are r elated to neuropsychological dysfunction after cardiac surgery. S100 protei n has early and late release patterns after CPB; the early pattern may be d ue to sub-clinical brain injury. The late release pattern may be due to per ioperative cerebral complications. Patients undergoing intracardiac operati ons combined with coronary artery bypass surgery are more susceptible to br ain injury and have higher levels of S100 after CPB. furthermore, adults an d children undergoing deep circulatory arrest are more susceptible to brain injury, in terms of higher S100 protein release after CPB. Serum S100 prot ein levels are reduced after using arterial line filtration and covalent-bo nded heparin to coat the inner surface of the CPB circuit.