Dose-response curve and time-course of effect of vecuronium in male and female patients.
To determine the differences between men and women in the dose-response curve and the time-course of effect of vecuronium, we studied 60 adult patients (30 male and 30 female), ASA I, age 18-51 yr, undergoing elective plastic surgery. Anaesthesia was maintained with nitrous oxide 60% in oxygen; thiopentone and incremental doses of fentanyl were given as required. Neuromuscular function was assessed mechanomyographically using the train-of-four (TOF) stimulation at the wrist every 12 s. The percentage depression of T1 was used as the study variable. The dose-response relationship of vecuronium was determined by a cumulative dose-response technique. The dose-response curve in men was shifted in a parallel fashion to the right, indicating a decrease in the sensitivity to vecuronium-induced neuromuscular block, compared with women. The ED50, ED90 and ED95 of vecuronium were 23.9 (4.7), 45.4 (11.2) and 55.7 (14.3) micrograms kg-1 in men and 18.4 (3.7), 33.5 (7.8) and 39.8 (9.6) micrograms kg-1 in women respectively. There were statistically significant differences in these values between the two groups (P < 0.01 in each instance). After a total dose of vecuronium 80 micrograms kg-1, neuromuscular block was significantly longer in women than in men. The duration of peak effect, clinical duration, and the total duration were 18.7 (7.1), 26.6 (8.8) and 50.6 (16.0) min respectively in men and 26.0 (7.2), 37.1 (11.2) and 65.9 (20.7) min in women. They differed significantly between men and women (P < 0.005 in each case).
Department of Anaesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences, Beijing, People's Republic of China.
F S
FS
Xue
X
X
Liao
J H
JH
Liu
S Y
SY
Tong
Y M
YM
Zhang
R J
RJ
Zhang
G
G
An
L K
LK
Luo
D000293:Adolescent; D000328:Adult; D000768:Anesthesia, General; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000502:physiology; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D012737:Sex Factors; D013997:Time Factors; D014673:Vecuronium Bromide / Q000494:pharmacology*
D003473:Neuromuscular Nondepolarizing Agents; D014673:Vecuronium Bromide