The purpose of this study is to explore characteristic changes of EEG epileptiform discharges in patients under CPB and correlation with POD

Cardiac surgery under cardiopulmonary bypass (CPB) as a result of the surgery itself great trauma and CPB this special process can lead to cerebral hypoperfusion, cerebral ischemia, increased in patients with postoperative neurological complications, the incidence of postoperative cognitive dysfunction can up to 44-53%.Postoperative delirium (POD) is not only increase the incidence of postoperative cognitive dysfunction forward, affect the quality of postoperative recovery and increased hospital costs, also associated with postoperative mortality. Although the clinical use of different drugs and technology improve the POD, but due to the mechanism is still unclear, is still lack of effective control measures. Electroencephalogram (EEG) can measure the cerebral cortex and subcortical local potential activities, to reflect the activities of the neurons in the brain. CPB can cause the abnormal vibration of brain waves, epileptiform discharges is the result of abnormal discharge of brain neurons, which is correlated with the occurrence of cognitive dysfunction.But whether EEG epileptiform discharges is related to the POD is uncertain.While epileptic seizures can be treated with anticonvulsant drugs, so the detection and treatment of early epileptic seizures may have important clinical significance for the occurrence of POD. Therefore, the main purpose of this study is to explore characteristic changes of EEG epileptiform discharges in patients under CPB and correlation with POD, offer the theoretical foundation for delirium early warning and prevention.

Inclusion Criteria:

1. ASA II-III;
2. No cognitive impairment was assessed one day before surgery;
3. Patients undergoing elective CPB cardiac surgery(valvular heart surgery and coronary bypass surgery) and signed informed consent.

Exclusion Criteria:

1. Non-CPB surgery, macrovascular surgery, heart transplantation, correction of congenital heart disease;
2. Stroke, schizophrenia, depression, Parkinson's disease, epilepsy or dementia;
3. Inability to communicate with language impairment or major hearing or visual impairment;
4. Liver function child-pugh Grade C, severe liver dysfunction;
5. Severe renal insufficiency requires preoperative renal replacement therapy;
6. A past history of intraoperative knowledge.

Cardiac surgery patients