Abstract: Objective To analyze the value of monitoring intraoperative regional cerebral oxygen saturation(rSO-2) and serum heme oxygenase-1(HO-1) and superoxide dismutase(SOD) levels for predicting postoperative cognitive dysfunction(POCD) of patients with rectal cancer.Methods A sample of 113 patients receiving laparoscopic radical resection for rectal cancer in our hospital from January 2019 to September 2021 were retrospectively analyzed.Patients were classified into POCD group and non-POCD group according to mini-mental state examination(MMSE) score.Results A total of 46 patients had POCD and 67 had no POCD after surgery.The rSO-2 values at T3~T5 were significantly higher in POCD group than in non-POCD group(P<0.05).The change rate of rSO-2 was also significantly higher in POCD group than in non-POCD group,the level of POCD group was higher than that of no POCD group (P<0.05).Postoperative MMSE score had no significant changes in non-POCD group(P>0.05),while the MMSE score after operation was significantly lower in POCD group than in non-POCD group(P<0.05).The change rate of rSO-2,serum HO-1 and SOD levels were negatively correlated with postoperative MMSE scores(P<0.05).ROC curve analysis showed that the AUC,sensitivity and specificity were 0.702,73.9% and 70.1% under rSO-2 change rate curve,those were 0.779,84.8% and 73.1% under HO-1 curve,and were 0.839,87.0% and 82.1% under SOD curve.Conclusion The abnormally increased rSO-2 change rate,and elevated serum HO-1 and SOD levels in patients undergoing laparoscopic radical resection for rectal cancer are closely related to the development of POCD. 

Key words: rectal cancer, regional cerebral oxygen saturation, heme oxygenase-1, superoxide dismutase, cognitive dysfunction