Effect of lower extremity ischemic preconditioning on postoperative cognitive function in elderly patients undergoing radical resection of rectal carcinoma

Abstract

Objective To evaluate the effect of lower extremity ischemic preconditioning on postoperative cognitive function in the elderly patients undergoing radical resection of rectal carcinoma.Methods Eighty ASA physical status Ⅰ-Ⅲ patients of both sexes,aged 65-78 yr,weighing 45-81 kg,undergoing elective radical resection of rectal carcinoma,were randomly divided into 2 groups (n =40 each):control group (group C) and extremity ischemic preconditioning group (group P).Anesthesia was induced with midazolam,etomidate,sufentanil and cisatracurium besylate.The patients were endotracheally intubated and mechanically ventilated.Anesthesia was maintained with iv infusion of propofol and remifentanil and intermittent iv boluses of cisatracurium besylate.BIS value was maintained at 40-60 during operation.The patients underwent three cycles of 5 min left lower extremity ischemia which was induced by a manual cuff-inflator placed on the left lower extremity and inflated to 200 mmHg,followed by 5 min deflation in group P.Patient-controlled intravenous analgesia with sufentanil was used for postoperative analgesia.Before induction,at the end of operation and at 1 and 7 days after operation,blood samples were collected from the jugular bulb for determination of serum S-100β concentrations using ELISA.Postoperative cognitive dysfunction (MMSE score ＜ 24) at 7 days after operation was recorded.Results The serum S-100β concentration was significantly lower at the end of operation and 1 and 7days after operation in group P than in group C (P ＜ 0.05).The incidence of postoperative cognitive dysfunction in both groups was 17.9％ and there was no significant difference between the two groups (P ＞ 0.05).Conclusion Lower extremity ischemic preconditioning can decrease blood S-100β concentrations,but it provides no improvement in postoperative cognitive dysfunction in elderly patients undergoing radical resection of rectal carcinoma. Key words: Ischemic preconditioning; Lower extremity; Cognition disorders; Aged