[Prolongation and recovery under sevoflurane anesthesia of neuromuscular blocking action of vecuronium].

Thirty-seven patients (ASA I or II) undergoing elective abdominal surgery were randomly allocated to four groups, which were anesthetized with nitrous oxide 67%, oxygen 33% and sevoflurane 0%, 1%, 2% and 3% respectively. We administered clinically used doses of vecuronium for abdominal surgery and studied the duration (the time from 100% block after injection to 20% recovery) and the recovery time (time from the last injection of vecuronium to 20% recovery). No prolongation of neuromuscular blocking effect was demonstrated with the initial dose of vecuronium. Significant prolongations of the duration and the recovery time were demonstrated with the maintenance dose of vecuronium only with sevoflurane over 2% and the effect was concentration-dependent.