The relationship between rate of administration of an intubating dose of rocuronium and time to 50% and 90% block at the adductor pollicis muscle.
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.
De Haes
A
A
Research Group for Experimental Anesthesiology and Clinical Pharmacology, University of Groningen, Groningen, The Netherlands.
Eleveld
D J
DJ
Wierda
J M
JM
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
D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium