The Clinical Study On Relation Between Regional Cerebral Oxygen Saturation And Postoperative Delirium In Patients During Cardiopulmonary Bypass

Part 1The clinical study on relation between regional cerebral oxygen saturation and postoperative delirium in patients during cardiopulmonary bypassObjective To study the relation between regional cerebral oxygen saturation (rScO2) and postoperative delirium in patients who undergoing cardiopulmonary bypass (CPB) of cardiac surgery.Methods Twenty-eight patients for elective cardiac surgery were enrolled in the study. Postoperative delirium was assessed by the CAM-ICU everyday during 7 days after operation. All of the patients were divided into two groups (delirium group and non-delirium group) based on the postoperative delirium. The rScO2 of all patients were monitored during operation. The value of the mean rScO2 in the 7 periods (preoperatiion,preinducement,from inducement to the beginning of CPB,from the beginning of CPB to the end of temperature cooling,low temperature period,from the beginning of warming to the end of CPB,the 30 minutes after CPB) during the operation period were measured. The area under the curve of the rScO2 was calculated. The blood gas analysis have been evaluated during perioperative period (Preoperative,the 30 min after the beginning of CPB,the end of CPB,enter ICU after operation, the 24 hours after operation). The difference in PaO2,PaCO2,HCT,Glu and Lac were compared.Results All patients survived after the operation and were discharged from the hospital in good condition.The rScO2 of non-Delirium group in t5(low temperature period),t6(from the beginning of warming to the end of CPB) were significantly lower than the t1(preoperatiion),t2(preinducement),t3(from inducement to the beginning of CPB),t4(from the beginning of CPB to the end of cooling),t7(the 30 minutes after CPB).The rScO2 of delirium group in t5(low temperature period) was significantly lower than the t1(preoperatiion),t2(preinducement),t3(from inducement to the beginning of CPB),t4(from the beginning of CPB to the end of cooling),t7(the 30 minutes after CPB). The rScO2 of delirium group in t6(from the beginning of warming to the end of CPB) was significantly lower than the t1(preoperatiion),t3(from inducement to the beginning of CPB),t7(the 30 minutes after CPB) (p<0.05)The base line of rScO2 was 65.2%。The AUC-rScO2 of delirium group was significantly larger than the non-delirium group. The PaO2 in the patients of delirium group and non-delirium group had no difference. The PaCO2 of delirium group and non-delirium group reduced. The PaCO2 of delirium group was less than 30mmHg during CPB. Both the delirium group and non-delirium group were hemodilution. The GLU of delirium group and non-delirium group were more than 6.11mmol/l. The Lac of delirium group and non-delirium group increased from the beginning of CPB to the 24 hours after operation.Conclusions The low rScO2 was one of the causes for postoperative delirium in patients undergoing cardiopulmonary bypass of cardiac surgery. So we should monitor the rScO2 during operation to avoid profound cerebral desaturation. Part 2The Trendline of the consistence of s100B during peri-cardiopulmonary bypassObjective We detect the consistence of s100B to correlat with the AUC-rScO2 and try to know the damage of brain in patients undergoing cardiopulmonary bypass (CPB) of cardiac surgery.Methods We set up the monitoring (ECG,MAP,CVP,urine volume,temperature,SaO2,rScO2 and PetCO2) when the patients entered the operation room.The blood sample were taken before CPB,at the end of CPB and 24 hours after operation in 28 patients underwent cardiopulmonary bypass of cardiac surgery so as to detect the the consistence of s100B by ELISA (before CPB,at the end of CPB and 24 hours after operation). We analysed the correlativity between the S100B and the AUC-rScO2.Results All patients survived after the surgery and were discharged in good condition. The equation of standard curve in S100B was y=1250.8x-235.51,R2=0.9071, The concentration of S100B was 0.61±0.15μmol/l before the CPB. The concentration of S100B was 1.34±0.32μmol/l at the end of CPB. The concentration of S100B was 0.65±0.14μmol/l the 24 hours after the operation. The consistence of s100B at the end of CPB was more than the time before CPB (P<0.05). The consistence of s100B at 24 hours after CPB was less than the time at the end of CPB (P<0.05). The equation of fitted curve between the AUC-rScO2 and the S100B was y=-0.2381x+510.55,R2=0.0147. (P=0.539).Conclusions The S100B was significantly higher in patients during cardiopulmonary bypass (CPB) of cardiac surgery. The correlativity between the S100B and the AUC-rScO2 wan't significantly.