F S Xue1, Y M Zhang, X Liao, J H Liu, G An. 1. Department of Anesthesiology, Plastic Surgery Hospital, Beijing, People's Republic of China. angangbj@263.net
Abstract
STUDY OBJECTIVE: To determine the influences of age and gender on the dose response and the time course of effect of atracurium. DESIGN: Prospective, nonrandomized, clinical comparison. SETTING: Operating room, Plastic Surgery Hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College. PATIENTS: 72 adult ASA physical status I patients (38 male and 34 female), aged 15 to 59 years, scheduled for elective plastic surgery. INTERVENTIONS: Patients were divided into the three groups on the basis of age: Group 1, patients aged 15-29 years (n = 32); Group 2, patients aged 30-40 years (n = 21); and Group 3, patients aged 41-59 years (n = 19). Anesthesia was maintained with 60% nitrous oxide in oxygen, thiopental, and incremental doses of fentanyl as required. The dose-response relationship of atracurium was determined by a cumulative dose-response technique. MEASUREMENTS AND MAIN RESULTS: Neuromuscular function was assessed mechanomyographically with train-of-four stimulation at the wrist every 12 seconds and the percentage depression of first twitch (T1) response was used as the study variable. Age and gender significantly affected the dose-response relationship and time course of recovery of atracurium. Advancing age was associated with a reduced effective doses (ED50, ED90, and ED95) of atracurium and a longer duration of action. The effective doses of atracurium were greater, and its duration of action was shorter in men than in women. There were significant differences in the 50%, 90%, and 95% effective dose (ED50, ED90, and ED95) of atracurium, and clinical duration and total duration following administration of atracurium 400 micrograms/kg among the three age groups, and between men and women. CONCLUSIONS: Age and gender have significant effects on the dose response and time course of effect of atracurium. Older patients and women are more sensitive to atracurium-induced neuromuscular block than are young patients and men.
STUDY OBJECTIVE: To determine the influences of age and gender on the dose response and the time course of effect of atracurium. DESIGN: Prospective, nonrandomized, clinical comparison. SETTING: Operating room, Plastic Surgery Hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College. PATIENTS: 72 adult ASA physical status I patients (38 male and 34 female), aged 15 to 59 years, scheduled for elective plastic surgery. INTERVENTIONS:Patients were divided into the three groups on the basis of age: Group 1, patients aged 15-29 years (n = 32); Group 2, patients aged 30-40 years (n = 21); and Group 3, patients aged 41-59 years (n = 19). Anesthesia was maintained with 60% nitrous oxide in oxygen, thiopental, and incremental doses of fentanyl as required. The dose-response relationship of atracurium was determined by a cumulative dose-response technique. MEASUREMENTS AND MAIN RESULTS: Neuromuscular function was assessed mechanomyographically with train-of-four stimulation at the wrist every 12 seconds and the percentage depression of first twitch (T1) response was used as the study variable. Age and gender significantly affected the dose-response relationship and time course of recovery of atracurium. Advancing age was associated with a reduced effective doses (ED50, ED90, and ED95) of atracurium and a longer duration of action. The effective doses of atracurium were greater, and its duration of action was shorter in men than in women. There were significant differences in the 50%, 90%, and 95% effective dose (ED50, ED90, and ED95) of atracurium, and clinical duration and total duration following administration of atracurium 400 micrograms/kg among the three age groups, and between men and women. CONCLUSIONS: Age and gender have significant effects on the dose response and time course of effect of atracurium. Older patients and women are more sensitive to atracurium-induced neuromuscular block than are young patients and men.