Effect Of Flumazenil On Postoperative Cognitive Function And Recovery With Isoflurane Anesthesia

Objective : To investigate the postoperative cognitive recovery in patients receiving uterine laparoscopy with isoflurane anesthesia following intervenous administered flumazenil.Methods: Eighty ASA I or II female patients aged 40～55 years scheduled for elective uterine laparoscopy under isoflurane general anesthesia were studied. Patients with psychiatrical or neurological disorders or taking hypontics regularly were excluded. General anesthesia was induced with midazolam 0.03 mg/kg, fentanyl 4μg/kg and propofol 1～2 mg/ kg, Tracheal intubation was facilitated with by succinycholine 2 mg/kg. The patients were then mechanically ventilated and PETCO2 was maintained at 30～45mmHg. Anesthesia was maintained with 1.0%～2.0% isoflurane and intermittent intervenous boluses of fentanyl and vecuronium. ECG, Bp, HR, SpO2 , PETCO2 and end-tidal-isoflurane concentrantion were monitored during operations. At the end of the procedure, isoflurane concentration was declined to 0.4 MAC, neostigmine 0.04 mg/kg was given and isoflurane was discontinued as two twitches of the train-of–four (TOF) were present. Patients were assigned to receive flumazenil (Group A) or placebo (Group B) as all four twitches of the TOF were present and patients were extubated when tidal volume was over 6 ml/kg immediately. All patients were transferred to recovery room and stayed for 120min. All patients received fentanyl 0.03μg·kg-1·h-1 for postoperation analgesia at 30min after surgery . The patients were asked to perform five cognitive tests before operation(T1) and repeated at 30 min (T2), 1 h (T3), 2 h (T4), 24 h (T5) after flumazenil or placebo: (1) revolved Chinese character test, (2) word recall test, ( 3) picture recall test, (4) calculate ability test, (5) the Stroop Color Word Test (SCWT).Results: The two groups were comparable in demographic data. Awakening time in group A was significantly shorter than that in group B ((9.9±5.7) min, (14.1±6.5) min respectively, P<0.01). Both groups showed an impairment of cognitive functions up to 24 h after isoflurane anesthesia. After isoflurane anesthesia, cognitive impairment lasted more than 2 h in word recall test and SCWT-2, but less than 2 h in Chinese character revolved test, picture recall test, calculate ability test and SCWT-1.Conclusion: Within 1 h following administration, flumazenil could partially reverse some cognitive and psychomotor impairments resulted from isoflurane anesthesia. Objective: To testify the hypothesis that flumazenil, a benzodiazepine antagonist, may improve recovery from isoflurane anesthesia.Methods: Eighty patients aged 60-75 years undergoing elective orthetic surgery under general anesthesia (n=40) were studied. Patients with psychiartrical or neurological disorders or taking hypontics regularly were excluded. General anesthesia was induced with midazolam 0.04 mg/ kg, fentanyl 4μg/ kg and propofol 1-2 mg/ kg, Tracheal intubation was facilitated with by succinycholine 2 mg/ kg. The patients were then mechanically ventilated and PETCO2 was maintained at 30-40 mmHg. Anesthesia was maintained with 1.0%-2.0% isoflurane and intermittent intravenous boluses of fentanyl and vecuronium. ECG, Bp, HR, PETCO2 and end-tidal-isoflurane concentrantion were monitored during operation. At the end of the procedure, isoflurane concentration was declined to 0.4 MAC, neostigmine 0.04 mg/kg was given and isoflurane was discontinued as two twitches of the train-of -four (TOF) were present. Patients were assigned to receive flumazenil (Group A) or placebo (Group B) as all four twitches of the TOF were present and patients were extubated immediately. All patients were transferred to recovery room and stayed for 120min. All patients received fentanyl 0.03μg·kg-1·h-1 for postoperation analgesia at 30min after surgery . A ten-point vigilance score and recovery of neurological status were assessed at 0, 5, 10, 20, 30, 40, 50, 60 min after flumazenil or placebo. Reversal of amnesia was recorded at 60 min and 24 h postsurgery and general subjective feeling were assessed.Results A ten-point vigilance score showed better recovery in flumazenil- treated patients than those who received placebo(60-min after isoflurane:9.1±1.5 vs 8.3±1.5 P<0.05). Patients reached a better neurological scale(2.9±0.8) in group A compared to (2.8±0.4) that in group B (P<0.05). Reversal of amnesia was superior in group A at 60 min and at 24 h postoperatively and more flumazenil-treated patients rated recovery as"pleasant"(P<0.05). Conclusion: Flumazenil could improve recovery and neuromotor functions and the overall quality of emergence, including patients` subjective feeling following isoflurane anesthesia.