title: Effect of isoflurane and sevoflurane on the magnitude and time course of neuromuscular block produced by vecuronium, pancuronium and atracurium.
abstract: We have compared the ability of equipotent concentrations of isoflurane and sevoflurane to enhance the effect of non-depolarizing neuromuscular blocking drugs. Ninety ASA I and II patients of both sexes, aged 18-50 yr, were stratified into three blocker groups (Vec, Pan and Atr), to undergo neuromuscular block with vecuronium (n = 30), pancuronium (n = 30) or atracurium (n = 30), respectively. Within each group, patients were allocated randomly to one of three anaesthetic subgroups to undergo maintenance of anaesthesia with: (1) alfentanil-nitrous oxide-oxygen (n = 10); (2) alfentanil-nitrous oxide-oxygen-isoflurane (n = 10); or (3) alfentanil-nitrous oxide-oxygen-sevoflurane (n = 10) anaesthesia. During maintenance of anaesthesia, end-tidal concentrations of isoflurane, sevoflurane and nitrous oxide were 0.95, 1.70 and 70%, respectively. Both the evoked integrated electromyogram and mechanomyogram of the adductor pollicis brevis muscle were measured simultaneously. In the Vec and Pan groups, a total dose of 40 micrograms kg-1 of vecuronium or pancuronium, respectively, was given, and in the Atr group a total dose of atracurium 100 micrograms kg-1. Each blocker was given in four equal doses and administered cumulatively. We showed that 0.95% isoflurane and 1.70% sevoflurane (corresponding to 0.8 MAC of each inhalation anaesthetic, omitting the MAC contribution of nitrous oxide) augmented and prolonged the neuromuscular block produced by vecuronium, pancuronium and atracurium to a similar degree.
authors.affiliation: Institute for Anaesthesiology, University Hospital of Nijmegen, The Netherlands.
authors.forename: L E
authors.initials: LE
authors.lastname: Vanlinthout
authors.forename: L H
authors.initials: LH
authors.lastname: Booij
authors.forename: J
authors.initials: J
authors.lastname: van Egmond
authors.forename: E N
authors.initials: EN
authors.lastname: Robertson
mesh_terms: D000293:Adolescent; D000328:Adult; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D001279:Atracurium / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004576:Electromyography; D004987:Ethers / Q000494:pharmacology; D005260:Female; D006801:Humans; D007530:Isoflurane / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D008738:Methyl Ethers; D008875:Middle Aged; D009407:Nerve Block; D009469:Neuromuscular Junction / Q000187:drug effects*; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D010197:Pancuronium / Q000494:pharmacology; D000077149:Sevoflurane; D014673:Vecuronium Bromide / Q000494:pharmacology
chemical_list: D018685:Anesthetics, Inhalation; D004987:Ethers; D008738:Methyl Ethers; D003473:Neuromuscular Nondepolarizing Agents; D001279:Atracurium; D000077149:Sevoflurane; D014673:Vecuronium Bromide; D007530:Isoflurane; D010197:Pancuronium