[Hemodynamic effects of the benzodiazepine antagonist flumazenil following laparotomy under total intravenous anesthesia using midazolam].

Inhalational anesthetic agents, particularly nitrous oxide, are potentially hazardous to both the patient and operating room personnel. Recent efforts have been directed towards the development of intravenous anesthetic techniques using combinations of a hypnotic with an analgesic. The hypnotic used in such a combination should have a short elimination half-life, little or no influence on hemodynamics, and no side effects. Benzodiazepines are likely candidates for total intravenous anesthesia (TIVA) since they combine hemodynamic stability and paucity of unwanted effects with the ability to induce amnesia for the entire perioperative period. They do have long elimination half-lives; even midazolam, the shortest-acting benzodiazepine, has a half-life of 2 to 3 h. This disadvantage might be counteracted by the use of flumazenil, the recently introduced, specifically acting benzodiazepine antagonist. The aim of this study was to determine the effects of rapid awakening following flumazenil after major abdominal surgery with benzodiazepine-fentanyl TIVA. Six patients (4 male, 2 female) scheduled for elective laparotomies participated in this pilot study. The average duration of surgery was 2.2 +/- 0.9 h. The patients were given 2 mg flunitrazepam p.o. the evening before surgery and 1 h before being brought to the operating room. Baseline pre-induction values were obtained 15 min after inserting catheters and attaching the EEG electrodes. Fentanyl (0.005 mg/kg) was given as a bolus injection followed by a rapid midazolam infusion. The infusion rate was calculated using the method of Wagner et. al. from the data of Lauven et al. to give plasma concentrations of 500 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)