title: Dependence of the neuromuscular blocking effect of atracurium upon its disposition.
abstract: We have assessed the profiles of plasma concentration of atracurium and its neuromuscular blocking effect on the first response of the train-of-four measured by electromyography after a short infusion of atracurium 0.25 mg kg-1, in 38 patients anaesthetized by one of three techniques. Measures of the temporal profile of neuromuscular block were found to correlate with pharmacokinetic variables. When anaesthetic technique was taken into account in a multivariate model, the time to onset of 10% deprssion of T1:T0 correlated positively with the central volume of distribution (P less than 0.05). The change in T1:T0 during the 1 min after 10% depression, and the logit of maximum depression were both correlated negatively with the central volume of distribution (P less than 0.05 and P less than 0.01, respectively). Both the times to 20% and 50% recovery of T1:T0 correlated strongly negatively with clearance (P less than 0.0001 for both measures). The findings support the conclusion that the effect of atracurium is dependent upon its disposition.
authors.affiliation: University Department of Anaesthesia, Royal Liverpool Hospital.
authors.forename: C J
authors.initials: CJ
authors.lastname: Parker
authors.forename: J M
authors.initials: JM
authors.lastname: Hunter
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D000769:Anesthesia, Inhalation; D001279:Atracurium / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D003864:Depression, Chemical; D005260:Female; D006801:Humans; D008297:Male; D008874:Midazolam; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects*
chemical_list: D001279:Atracurium; D008874:Midazolam