The Effect Of Different Anesthesia Depth With BIS On The Cognitivefunction And S-100β Protein In Elderly Patients With Abdominal Surgery

Objective: To investigate the effects of different BIS values on postoperative cognitive dysfunction(POCD)and S-100β protein(S-100β)in the early stage of postoperation.Methods: Fifty patients who were scheduled for selective abdominal surgery under general anesthesia(male 34 cases,female 16 cases,aged 65 to 75 years, ASAⅠorⅡ) were randomly divided into two groups: light anesthesia group(group L, n = 25, BIS value was maintained at 50 to 59) and deep anesthesia group(group D, n = 25, BIS value was maintained at 30 to 39). BP, HR, Sp O2, ECG, PETCO2, inhaled anesthetic concentration and BIS values were recorded on time points of 5 minutes after the patuents entering the operating room, before endotracheal, intubation, incision, two hours after incision, three hours after incision and at the end of surgery. At the same time, compared the differences of the operation time, anesthesia time, propofol, fentanyl, midazolam and VAS score. Blood samples were taken at 10 min before anesthesia, immediate end of surgery and at 1 d and 2 d after operation for measured S-100β concentration.Results: BIS value of group D were lower than group L on T2, T3 and T4. The propofol dosage of group D was significantly greater than that in group L(P<0.05). The concentration of serum S-100β increased significantly immediate and 48 h after operation in both groups compared with 10 min before anesthesia(P<0.05). It was still higher 24 hours after operation than before anesthesia. But there was no statistic difference. Compared with the end of surgery, the concentration of serum S-100β in two groups on 24 h after surgery were significantly decreased(P<0.05). The concentration of serum S-100β in group L on the end of surgery and 24 h after surgery were higher than that in group D significantly(P<0.05). Compared with 1 d before surgery, postoperative 1 d MMSE scores in two groups and postoperative 3 d MMSE score in group L decreased significantly(P<0.01). Compared with postoperative 3 d, postoperative 7 d MMSE socre in group L increased significantly(P<0.01). Postoperative 1, 3 d MMSE score in group D were significantly higher than group L(P<0.05). Compared with 1 d before surgery, TMT completion time in two groups on 1 d after surgery were significantly prolonged(P<0.01). Compared with 1 d after surgery, TMT completion time in two groups on 3 d after surgery were significantly shortened(P<0.01). Compared with 3 d after surgery, TMT completion time in group L on 7 d after surgery was significantly shortened(P<0.01). TMT completion time in group D on 1, 3 d postoperative were significantly shorter than group L(P<0.05). POCD incidence of group D on 1 d after surgery was lower than that in group L(P<0.05).Conclusion: Depth of anesthesia can affect brain damage. By adjusting the depth of anesthesia can reduce the S-100β protein levels and reduce brain damage. Deep anesthesia is conducive to the protection of the patient’s brain. With MMSE and TMT evaluate postoperative cognitive function, 54% had impaired cognitive function. Deep anesthesia can reduce the incidence of early POCD, for clinical reference.