Effects of different depths of sedation during combined intravenous-inhalational anesthesia on postoperative cognitive function in patients undergoing gynecological laparoscopic surgery

Abstract

Objective To investigate the effects of different depths of sedation during combined intravenous-inhalational anesthesia on postoperative cognitive function in patients undergoing gynecological laparoscopic surgery.Methods Ninety ASA Ⅰ or Ⅱ patients,aged 20-64 yr,with a body mass index of 19-30 kg/m2,scheduled for elective gynecological laparoscopic operation,were randomly divided into 3 groups (n =30 each).Anesthesia was induced with midazolam,fentanyl,propofol and rocuronium.The patients were tracheal intubated and mechanically ventilated.Anesthesia was maintained with inhalation of sevoflurane (end-tidal concentration 1.0％-1.5 ％),iv infusion of remifentanil and intermittent iv boluses of rocuronium.The infusion rate of remifentanil was adjusted to maintain BIS value:30 ＜ BIS value ≤ 40 in group Ⅰ,40 BIS value ≤ 50 in group Ⅱ and 50 ＜ BIS value≤60 in group Ⅲ.Cognitive function was assessed using Mini-Mental State Examination (MMSE) and TrailMaking Test (TMT) at 1 d before anesthesia and 1 d after surgery.Results MMSE scores were ＞ 24 at 1 d before anesthesia and 1 d after surgery in all the three groups,and there was no significant difference within each group and among the three groups (P ＞ 0.05).Compared with the baseline value,TMT completion time was significantly prolonged at 1 d after surgery in groups Ⅰ and Ⅲ,while shortened in group Ⅱ (P ＜ 0.05).Compared with groups Ⅰ and Ⅲ,TMT completion time was significantly shortened at 1 d after surgery in group Ⅱ (P ＜0.05).Conclusion The depth of sedation,40 ＜ BIS value ≤ 50,during combined intravenous-inhalational anesthesia with sevoflurane and remifentanil has less influence on postoperative cognitive function in patients undergoing gynecological laparoscopic surgery. Key words: Anesthesia, inhalation; Anesthesia, intravenous; Deep sedation; Cognition disorders; Postoperative complications