title: Onset/offset characteristics and intubating conditions of rapacuronium: a comparison with rocuronium.
abstract: We compared onset and offset of action and tracheal intubating conditions after rapacuronium and rocuronium in 60 patients in a randomized, assessor-blinded study. Following induction of anaesthesia with propofol 2.5 mg kg-1, either rapacuronium 1.5 mg kg-1 (n = 30) or rocuronium 0.6 mg kg-1 (n = 30) was administered to facilitate tracheal intubation. Anaesthesia was maintained with either a propofol infusion (100 micrograms kg-1 min-1) or sevoflurane (1% end-tidal) with 66% nitrous oxide (N2O), n = 15 in each subgroup. Neuromuscular monitoring was performed using an electromyographic (EMG) device (Datex Relaxograph). The lag times (mean 42 (SD 11) s and 44 (16) s), maximum block (99 (2)% and 98 (3)%) and intubating conditions at 60 s (good-to-excellent in 86% and 84% of patients) were similar for rapacuronium and rocuronium, respectively. The onset time of rapacuronium was shorter than rocuronium (87 (20) vs 141 (65) s, P < 0.001), and the degree of block at 60 s was greater (69 (26) vs 50 (27)%, P < 0.05). Twenty-five per cent recovery was shorter with rapacuronium than rocuronium during propofol (15.0 (3.2) vs 39.1 (14.2) min, P < 0.001) and sevoflurane (15.1 (4.2) vs 47.8 (19.0) min, P < 0.001) anaesthesia. We conclude that rapacuronium 1.5 mg kg-1 had a more rapid onset, similar intubating conditions, and shorter recovery times than rocuronium 0.6 mg kg-1.
authors.affiliation: Department of Anaesthesiology and Pain Management, University of Texas Southwestern Medical Center at Dallas 75235, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Zhou
authors.forename: P F
authors.initials: PF
authors.lastname: White
authors.forename: J W
authors.initials: JW
authors.lastname: Chiu
authors.forename: G P
authors.initials: GP
authors.lastname: Joshi
authors.forename: K K
authors.initials: KK
authors.lastname: Dullye
authors.forename: L L
authors.initials: LL
authors.lastname: Duffy
authors.forename: W K
authors.initials: WK
authors.lastname: Tongier
mesh_terms: D000328:Adult; D000368:Aged; D000732:Androstanols / Q000494:pharmacology*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D004576:Electromyography / Q000187:drug effects; D004737:Enflurane / Q000008:administration & dosage / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D015742:Propofol / Q000008:administration & dosage; D000077123:Rocuronium; D016037:Single-Blind Method; D014673:Vecuronium Bromide / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000732:Androstanols; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D003473:Neuromuscular Nondepolarizing Agents; D014673:Vecuronium Bromide; D004737:Enflurane; C082938:rapacuronium; D000077123:Rocuronium; D015742:Propofol