title: Pharmacodynamics of high-dose vecuronium in children during balanced anesthesia.
abstract: To compare the speed of onset, intubating conditions, duration of action, and recovery from neuromuscular blockade with vecuronium to those with succinylcholine, 40 ASA physical status 1 or 2 children (ages 2-9 yr) were studied during N2O-O2-opioid anesthesia. Each child was randomly assigned to receive a bolus dose of one of the following muscle relaxants: succinylcholine 2.0 mg/kg (n = 10), vecuronium 0.1 mg/kg (n = 10), vecuronium 0.2 mg/kg (n = 10), or vecuronium 0.4 mg/kg (n = 10). The evoked electromyogram of the abductor digiti minimi to train-of-four stimulation was monitored. We found that with succinylcholine, the time to 95% twitch depression (speed of onset, mean +/- SD), 24 +/- 7 s, was significantly less than that with each dose of vecuronium: 0.1 mg/kg, 83 +/- 21 s; 0.2 mg/kg, 58 +/- 17 s; and 0.4 mg/kg, 39 +/- 11 s, respectively (P less than 0.05). The time to laryngoscopy and intubation did not differ significantly between succinylcholine (48 +/- 10 s) and vecuronium 0.4 mg/kg (57 +/- 13 s); however, both were significantly less than than with vecuronium 0.1 and 0.2 mg/kg (P less than 0.005). The intubating conditions were excellent in 100% of patients. The duration of action was least with succinylcholine (5.7 +/- 1.5 min) and increased with increasing doses of vecuronium: 0.1 mg/kg, 23.9 +/- 5.1 min; 0.2 mg/kg, 55.2 +/- 11.6 min; and 0.4 mg/kg, 74.6 +/- 9.9 min, respectively (P less than 0.001). The recovery index was most rapid with succinylcholine (1.6 +/- 0.4 min) and was slowest with vecuronium 0.4 mg/kg (22.6 +/- 2.1 min) (P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anaesthesia, Hospital for Sick Children, University of Toronto, Ontario, Canada.
authors.forename: M H
authors.initials: MH
authors.lastname: Sloan
authors.forename: J
authors.initials: J
authors.lastname: Lerman
authors.forename: B
authors.initials: B
authors.lastname: Bissonnette
mesh_terms: D000771:Anesthesia, Intravenous; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004576:Electromyography; D005283:Fentanyl; D006801:Humans; D009020:Morphine; D009126:Muscle Relaxation / Q000187:drug effects*; D011897:Random Allocation; D013390:Succinylcholine / Q000009:adverse effects / Q000494:pharmacology; D014673:Vecuronium Bromide / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D009020:Morphine; D014673:Vecuronium Bromide; D013390:Succinylcholine; D005283:Fentanyl