title: The relationship between rate of administration of an intubating dose of rocuronium and time to 50% and 90% block at the adductor pollicis muscle.
abstract: OBJECTIVE
  To determine the relationship between the rate of rocuronium injection and the onset time of neuromuscular block.
  
  
  METHODS
  After intravenous induction, 60 female patients (ASA I-II) were assigned randomly into 3 groups for rocuronium administration within 1-15, 15-30 or 30-60 seconds. Acceleromyography of the thumb was performed using train-of-four (TOF) stimulation. Times to 50% and 90% twitch depression of the first twitch of the TOF stimulation (T1) were recorded.
  
  
  RESULTS
  Injection time significantly influences time to 50% relaxation, but not time to 90% relaxation. Body mass index is negatively correlated with time to 50% and 90% relaxation.
  
  
  CONCLUSIONS
  We conclude that rate of injection influences only the initial phase of development of the block and that slower injection times do not significantly affect time to 90% relaxation at the adductor pollicis muscle.
authors.affiliation: Research Group for Experimental Anesthesiology and Clinical Pharmacology, University of Groningen, Groningen, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: De Haes
authors.forename: D J
authors.initials: DJ
authors.lastname: Eleveld
authors.forename: J M
authors.initials: JM
authors.lastname: Wierda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000732:Androstanols / Q000008:administration & dosage*; D015992:Body Mass Index; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000294:innervation; D019148:Neuromuscular Blockade; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage*; D000077123:Rocuronium; D009435:Synaptic Transmission / Q000187:drug effects; D013933:Thumb; D013997:Time Factors
chemical_list: D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium