Abstract：【Objective】 To observe the correlation between different depths of anesthesia and postoperative cognitive dysfunction (POCD) in elderly patients undergoing orthopaedic surgery, and to find the most suitable bispectral index (BIS) monitoring interval under total intravenous anesthesia for elderly patients. 【Methods】 A total of 120 elderly patients undergoing orthopedic surgery under total intravenous anesthesia were randomly divided into group A (BIS value of 41~50) and group B (BIS value of 51~60). The anesthesia method for all patients was propofol combined with remifentanil and vecuronium bromide. By adjusting the plasma concentration of propofol and remifentanil,the patient's anesthesia depth was maintained within the predetermined range. Surgical indexes, anesthesia effects MMSE scores at different time points, and the incidence of adverse reactions were compared between the two groups.【Results】 There were no significant differences between the two groups in HR or MAP before surgery (T0), at skin incision (T1), at fracture exploration (T2) or at the end of surgery (T3) (P>0.05). There was no significant difference in the target concentration of propofol between the two groups (P>0.05), while the target concentration of remifentanil was higher in group A than in group B (P<0.05). The recovery time and extubation time of group A were longer than those of group B (P<0.05). The MMSE scores of both groups at 2h and d1 after surgery were lower than those at d1 before surgery (P<0.05), and the scores of group A were significantly lower than group B (P<0.05). The incidence rates of POCD in group A at 2h and d1 after surgery were higher than group B (P<0.05). There was no significant difference in the incidence of POCD between the two groups on the d3 or d7 after surgery (P>0.05). There was no difference in the incidence of adverse reactions between the two groups (P>0.05). 【Conclusion】 The BIS value (51～60) can significantly reduce the incidence of POCD in elderly patients at 2h and d1 after orthopaedic surgery.
2018, Vol. 35 
