BACKGROUND: The effects of a muscle relaxant may Differ in elderly compared with young adult patients for a variety of the pharmacokinetic and pharmacodynamic reasons. Atracurium is eliminated by nonorgan dependent pathway, Hofmann elimination and ester hydrolysis. So there are some arguments for age-related differences. The purpose of this study was to compare the differences of the onset and duration of atracurium in young and elderly.
METHODS: Eighteen young adults(21-54yr) and 18 elderly(>65yr) patients anesthetized with nitruos oxide and enflurane. Atracurium(0.5 mg/kg) was given and then intubation was performed after T1 response was blocked more than 80%. Neuromuscular relaxation was measured by the first twitch of train-of-four (T1) response at the adductor pollicis after supramaximal stimulation of ulnar nerve at 2Hz every 12 sec. The onset(disappearence of T1) and duration of 5, 25, 50, 75% recovery time of T1 and recovery index(time for 25-75% recovery of T1) were recorded.
RESULTS: Onset of block was not significantly different between the young and elderly. Recovery time of 5, 25, 50, 75% and recovery index were not prolonged in elderly compared with young adults.
CONCLUSIONS: There were no significant differences between young and elderly adults in onset time, recovery time of 5, 25, 50, 75% and recovery index when atracurium is used in a single bolus dose. The results suggest that atracurium in elderly patients has similar onset and action duration compared with younger patients.
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