High concentration sevoflurane induction of anesthesia accelerates onset of vecuronium neuromuscular blockade

Abstract

Purpose: To investigate neuromuscular block using accelography after administration of vecuronium under sevoflurane 8% induction and maintenance with sevoflurane 2% in adults. Methods: Patients were allocated to three groups: (1) group I: anesthesia was induced and maintained with propofol and fentanyl (n=15), (2) group II: anesthesia was induced with propofol and maintained with N2O(66%)-O2-sevoflurane 2% (n=15), (3) group III: anesthesia was induced with sevoflurane 8% using a vital capacity inhalation induction and maintained with N2O(66%)-O2-sevoflurane 2% (n=15). 0.1 mg·kg-1 vecuronium was used for paralysis three minutes after anesthetic induction and reversed using intravenous 0.04 mg·kg-1 neostigmine with 0.02 mg·kg-1 atropine when the train-of-four (TOF) ratio returned to 25%. Results: The onset time from initial administration of vecuronium to maximal block in the group III was shorter than that in the groups I and II (139 ± 35, 193 ± 35 and 188 ± 47s, respectively: P < 0.05). The clinical duration from maximal block to 25% recovery of TOF ratio in group II and III was longer than that in the group I (47 ± 15, 48 ± 14 and 36 ± 10 min, respectively: P < 0.05). The reversal times from administration of neostigmine to 75% of TOF ratio in groups II and III were longer than that in the group I (196 ± 53, 208 ± 64 and 136 ± 28s, respectively: P < 0.05). Conclusions: Vital capacity inhalation induction of anesthesia with sevoflurane accelerates onset and prolongs duration of vecuronium neuromuscular block compared with propofol-fentanyl anesthesia.