Onset of neuromuscular block at the masseter and adductor pollicis muscles following rocuronium or succinylcholine.
OBJECTIVE
To compare the onset time of two different rocuronium doses (0.6 and 0.9 mg x kg(-1)) and succinylcholine (1.5 mg x kg(-1), preceeded by 0.06 mg x kg(-1) rocuronium) at the masseter and the adductor pollicis muscle.


METHODS
In a randomized study, 60 ASA I or II adult women, 18-65 yr of age, were anesthetized with propofol and fentanyl and nitrous oxide in oxygen. Neuromuscular monitoring was performed using acceleromyography simultaneously on the masseter and adductor pollicis. Onset time was measured at both muscles using supramaximal 0.1 Hz single twitch stimulation (square-wave pulse 0.2 msec duration).


RESULTS
In all patients, complete neuromuscular block occurred at the masseter and adductor pollicis muscles. Lag-time and onset time were faster at the masseter that at the adductor pollicis muscle in both rocuronium-groups (P < 0.01) and in the succinylcholine-group (P < 0.01). Furthermore, onset time was more rapid after 0.9 mg x kg(-1) rocuronium (65 +/- 7 s) than after succinylcholine (83 +/- 19 sec) at the AP (P < 0.05), but did not differ at the masseter (33 +/- 6 vs 36 +/- 7 sec).


CONCLUSIONS
Following rocuronium and succinylcholine, onset time is faster at the masseter than at the adductor pollicis muscle.
de Rossi
L
L
Clinic for Anaesthesiology and Intensive Care Therapy, Friedrich-Schiller-University, Jena, Germany. derossi@anae1.med.uni-jena.de
Preussler
N P
NP
Pühringer
F K
FK
Klein
U
U
D000293:Adolescent; D000328:Adult; D000732:Androstanols; D000768:Anesthesia, General; D005260:Female; D006801:Humans; D008406:Masseter Muscle / Q000187:drug effects*; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects*; D009213:Myography; D019148:Neuromuscular Blockade; D009467:Neuromuscular Depolarizing Agents; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium; D013390:Succinylcholine; D013997:Time Factors
D000732:Androstanols; D009467:Neuromuscular Depolarizing Agents; D003473:Neuromuscular Nondepolarizing Agents; D013390:Succinylcholine; D000077123:Rocuronium