Neuromuscular Blockade by Vecuronium during Induction with 5% Sevoflurane or Propofol

This randomized trial investigated whether 5% sevoflurane potentiated neuromuscular blockade by vecuronium. General anaesthesia was induced with 5% sevoflurane in oxygen in 16 patients or with propofol in 16 patients. After loss of consciousness, vecuronium was administered to all participants at randomly assigned doses of 25, 30, 35 or 40 mu g/kg. Neuromuscular blockade was assessed by use of acceleromyography to measure responses to train-of-four stimuli in the adductor pollicis and corrugator supercilii muscles. Maximum blockade was significantly more intense in the adductor pollicis among patients in the sevoflurane group than in the propofol group, whereas there was no significant between-group difference at the corrugator supercilii muscles. In both groups, maximum blockade at the corrugator supercilii was significantly less intense than that achieved at the adductor pollicis. In the dose-response analysis, the 50% and 95% effective doses were lower for sevoflurane than for propofol in both muscles, although this did not reach statistical significance. It is concluded that induction of general anaesthesia with sevoflurane might provide improved conditions for intubation and reduce airway problems.