Smoking increases the requirement for rocuronium.
OBJECTIVE
To compare the potency of rocuronium in non-smokers and smokers during general anaesthesia.


METHODS
In a randomized, open clinical study, 40 patients, 17-62 yr of age, were anaesthetized with propofol, alfentanil and nitrous oxide in oxygen. After obtaining individual dose-response curves for rocuronium, bolus doses of rocuronium were given to maintain neuromuscular block at 90-99% for 60 min. Evoked adductor pollicis electromyography (EMG) was used to monitor neuromuscular block.


RESULTS
The ED95 values (+/- SEM) for rocuronium were 460.5 +/- 28.9 and 471.5 +/- 22.1 micrograms.kg-1 for non-smokers and smokers, respectively (P:NS). However, doses of rocuronium to maintain 90-99% neuromuscular block (+/- SEM) were 620.1 +/- 46.7 and 747.4 +/- 56.0 micrograms.kg-1.hr-1 for non-smokers and smokers, respectively (P = 0.0504).


CONCLUSIONS
The results may indicate increased metabolism of rocuronium in smokers rather than increased requirement of rocuronium at the receptor site.
Rautoma
P
P
Department of Anaesthesia, Töölö Hospital, University of Helsinki, Finland.
Svartling
N
N
D000293:Adolescent; D000328:Adult; D000732:Androstanols / Q000008:administration & dosage; D000768:Anesthesia, General; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage; D000077123:Rocuronium; D012907:Smoking / Q000503:physiopathology*
D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium