title: Comparison of vecuronium- and atracurium-induced neuromuscular blockade in postpartum and nonpregnant patients.
abstract: The time-course of action of 0.1 mg/kg vecuronium and 0.5 mg/kg atracurium was investigated in nonpregnant and in postpartum patients within 4 days after delivery. The clinical duration of vecuronium, but not that of atracurium, was significantly prolonged in the latter group (P less than 0.001) and averaged 36 +/- 6 and 37 +/- 4 min for atracurium and 32 +/- 6 and 49 +/- 10 min for vecuronium in nonpregnant and in postpartum patients, respectively (mean +/- SD). In additional in vitro experiments in the rat phrenic nerve-hemidiaphragm preparation no difference could be observed in the neuromuscular blocking effects of vecuronium in postpartum and nonpregnant female rats. It is concluded that pregnancy-induced changes in liver blood flow and/or competition for the liver uptake of sexual hormones might interfere with the hepatic clearance of vecuronium in postpartum patients and thereby cause the observed prolongation of neuromuscular blockade.
authors.affiliation: Clinic for Anaesthesia, University of Innsbruck, Austria.
authors.forename: K S
authors.initials: KS
authors.lastname: Khuenl-Brady
authors.forename: J
authors.initials: J
authors.lastname: Koller
authors.forename: P
authors.initials: P
authors.lastname: Mair
authors.forename: F
authors.initials: F
authors.lastname: Pühringer
authors.forename: G
authors.initials: G
authors.lastname: Mitterschiffthaler
mesh_terms: D000328:Adult; D000818:Animals; D001279:Atracurium / Q000494:pharmacology*; D005260:Female; D006801:Humans; D009469:Neuromuscular Junction / Q000187:drug effects*; D049590:Postpartum Period / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D009435:Synaptic Transmission / Q000187:drug effects*; D013997:Time Factors; D014673:Vecuronium Bromide / Q000494:pharmacology*
chemical_list: D001279:Atracurium; D014673:Vecuronium Bromide