Flumazenil facilitates intraoperative arousal during scoliosis surgery: a randomized, doubleblind, placebo‐controlled study

Intraoperative arousal was evaluated in 24 patients (median age 16.5 years), undergoing spondylodesis with Cotrel–Dubousset or Harrington–Luque instrumentation. Flumazenil and placebo groups of 12 patients each were similar with respect to age, body weight, dosage of anaesthetic drugs and surgery times. Premedication consisted of diazepam 0.2–0.3 mg kg‐1 orally. Anaesthesia was induced with thiopentone 5–7 mg kg‐1, and maintained with 66% nitrous oxide in oxygen, and repeated doses of fentanyl, midazolam and atracurium. After placement and fixation of the metal rods, N2O was switched off, and either flumazenil or placebo was given in refracted doses until the patient responded to command. Intraoperative motor response times (medians with ranges), defined as the time from the injection of the first dose until the patient responded to command, were 2.5 min (1.0–5.2 min) after flumazenil, and 8.0 min (1.7–28.5 min) after placebo (P = 0.02). Five patients in the placebo group did not wake up within 10 min and received naloxone. The quality of awakening was similar in both groups. Two patients (one in each group) woke up violently and needed physical restraint. Postoperatively, motor responses were assessed after 12.0 min (5–42 min) in the flumazenil group, and after 15.2 min (4–40 min) in the placebo group (NS). Recovery from anaesthesia took 27.5 min (7–415 min) in the flumazenil group, and 25.0 min (8–160 min) in the placebo group (NS). One patient given flumazenil and one patient given placebo remembered moving their feet, but neither of them could recall anything unpleasant. It is concluded that flumazenil significantly shortens the time of intraoperative arousal during scoliosis surgery under midazolam, N2O/O2 anaesthesia, without having to compromise the analgesia provided by fentanyl. Flumazenil does not facilitate postoperative motor testing or recovery, nor does it affect recall of the intraoperative events.