title: Factors affecting neostigmine reversal of vecuronium block during sevoflurane anaesthesia.
abstract: We examined the influence of the concentration of sevoflurane and the degree of muscle block at the time of reversal on the activity of neostigmine. Ninety ASA 1-2 patients were anaesthetised with 0.2, 0.7 or 1.2 MAC of sevoflurane (30 patients each) in 66% nitrous oxide in oxygen. The electromyographic (EMG) response of the adductor digiti minimi was monitored at 20-s intervals after train-of-four stimulation of the ulnar nerve. The initial neuromuscular block was produced by vecuronium 100 micrograms.kg-1. When the amplitude of the first response (T1) values had recovered to 10%, 25% or 40% of the control, neostigmine 40 micrograms.kg-1 was administered. The train-of-four ratio values were recorded at 1-min intervals during the subsequent 15-min period. Higher endtidal concentrations (p < 0.0001) and more pronounced block at the time of reversal (p < 0.0001) were associated with a delayed recovery in the train-of-four ratio. In addition, the train-of-four ratio 15 min after neostigmine administration was more dependent on the sevoflurane concentration than on the degree of block present (p < 0.0001). These results confirm that neostigmine (40 micrograms.kg-1) can reverse vecuronium-induced but not sevoflurane-induced neuromuscular block.
authors.affiliation: Department of Anesthesiology and Reanimatology, Gunma University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Morita
authors.forename: D
authors.initials: D
authors.lastname: Kurosaki
authors.forename: H
authors.initials: H
authors.lastname: Tsukagoshi
authors.forename: H
authors.initials: H
authors.lastname: Shimada
authors.forename: H
authors.initials: H
authors.lastname: Sato
authors.forename: F
authors.initials: F
authors.lastname: Goto
mesh_terms: D000328:Adult; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000008:administration & dosage* / Q000494:pharmacology; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004987:Ethers / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D006801:Humans; D008738:Methyl Ethers; D008875:Middle Aged; D009388:Neostigmine / Q000494:pharmacology*; D009469:Neuromuscular Junction / Q000187:drug effects; D003473:Neuromuscular Nondepolarizing Agents / Q000037:antagonists & inhibitors*; D000077149:Sevoflurane; D014673:Vecuronium Bromide / Q000037:antagonists & inhibitors*
chemical_list: D018685:Anesthetics, Inhalation; D002800:Cholinesterase Inhibitors; D004987:Ethers; D008738:Methyl Ethers; D003473:Neuromuscular Nondepolarizing Agents; D000077149:Sevoflurane; D009388:Neostigmine; D014673:Vecuronium Bromide