Action Duration of Atracurium in the Elderly Patients

Jin, Myung Ho; Park, Dong Ho; Yang, Hong Seuk; Suh, Byung Te

Abstract

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 (21-54 yr) and 18 elderly (>65 yr) patients anesthetized with nitrous 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 (disappearance 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 onest 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.