ObjectiveTo monitor the depth of anesthesia during general anesthesia using bispectral index (BIS), and investigate the influence of BIS monitoring on postoperative delirium (POD) and survival of flap in aged patients undergoing radical resection of oral cancer.

MethodsA total of 68 patients undergoing radical resection of oral cancer aged from 65 to 80 years, with ASA physical status Ⅰ-Ⅲ were randomly divided into two groups.The BIS group (n=34) underwent adjustment of anesthesia to maintain a BIS value between 45-60.The non-BIS group (n=34) underwent standard intraoperative hemodynamic monitoring.The POD was assessed 1 day and 5 days after operation using confusion assessment method for intensive care unit (CAM-ICU).The occurrence of adverse reactions during operation was recorded.The use of drugs during the operation, the time of indwelling tracheal catheter after the operation, and the survival of flap were recoded.

ResultsThe incidence of POD was lower in the BIS group 11.8% (4/34) compared with non-BIS group 38.2% (13/34) on the first day after operation (P < 0.05).The incidence of POD was lower in the BIS group 8.8% (3/34) compared with non-BIS group 29.4% (10/34) on the fifth day after surgery (P < 0.05).Meanwhile, BIS monitoring could reduce the use of propofol during operation, reduce the occurrence of hypotension during operation, and reduce the use rate of ephedrine during operation.There was no significant difference in the delayed recovery, intraoperative awareness rate and remifentanil dosage between the two groups (P>0.05), and there was no significant difference in the survival rate of flap between the two groups (P>0.05).

ConclusionsBIS monitoring can reduce the incidence of POD in the elderly patients undergoing radical resection of oral cancer, but has no significant impact on the survival rate of flaps after surgery.