title: A randomized trial to identify optimal precurarizing dose of rocuronium to avoid precurarization-induced neuromuscular block.
abstract: OBJECTIVE
  The aim of this study was to examine the safe precurarizing dose of rocuronium required to avoid neuromuscular block after precurarization.
  
  
  METHODS
  Twenty-four female patients were randomly allocated into two groups of 12 patients each. General anesthesia was induced and maintained with remifentanil and propofol, and a laryngeal mask was inserted without the aid of a neuromuscular blocking agent. Patients were randomized to receive either 0.03 or 0.06 mg/kg rocuronium as a precurarizing dose. Neuromuscular block was monitored using acceleromyographic train-of-four (TOF) of the adductor pollicis muscle. Three minutes after the precurarization, all patients received suxamethonium 1.5 mg/kg and were graded on severity of fasciculations.
  
  
  RESULTS
  The average TOF ratio was kept above 0.9 even 3 min after precurarization with 0.03 mg/kg rocuronium. In contrast, in patients who received 0.06 mg/kg rocuronium, the ratios significantly decreased to 0.72 (0.14) [mean (SD), P < 0.004] and 0.68 (0.18) (P < 0.006) 2 min and 3 min after the precurarization, respectively. No visible muscle movement was observed following suxamethonium injection, except that one patient who received 0.03 mg/kg rocuronium showed very fine muscle movements of the fingertips.
  
  
  CONCLUSIONS
  Rocuronium at 0.06 mg/kg is an overdose for precurarization. The results of the present study demonstrate that a safe and effective precurarizing dose of rocuronium is 0.03 mg/kg.
authors.affiliation: Department of Anesthesiology, Surugadai Nihon University Hospital, 1-8-13, Kanda-Surugadai, Chiyoda-Ku, Tokyo 101-8309, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Fukano
authors.forename: Takahiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Mizutani
authors.forename: Shigeru
authors.initials: S
authors.lastname: Saeki
authors.forename: Setsuro
authors.initials: S
authors.lastname: Ogawa
mesh_terms: D000328:Adult; D000732:Androstanols / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008875:Middle Aged; D019148:Neuromuscular Blockade / Q000009:adverse effects*; D009469:Neuromuscular Junction / Q000187:drug effects; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage*; D000077123:Rocuronium; D013390:Succinylcholine / Q000494:pharmacology
chemical_list: D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D013390:Succinylcholine; D000077123:Rocuronium