Action Duration of Atracurium and Vecuronium in Patients with Renal Failure / 대한마취과학회지

BACKGROUND: Atracurium is eliminated by Hofmann elimination and ester hydrolysis, with minimal renal and hepatic excretion. It's action duration is not affected by renal function. Although metabolism of vecuronium is less dependent on the renal function than other steroid type neuromuscular blockers, the action duration of vecuronium is prolonged in renal failure. The purpose of this study is to compare the differences of the action duration of atracurium and vecuronium in patients with renal failure. METHODS: Forty patients with normal renal function and 40 patients with chronic renal failure were assigned to one of four groups: atracurium-normal (n=20, AC group), atracurium-renal failure (n=20, AK group), vecuronium-normal (n=20, VC group), vecuronium-renal failure (n=20, VK group). Anesthesia was induced with thiopental and maintained with the inhalation of nitrous oxide (50%) and isoflurane (0.5~1.5 vol%). Atracurium (0.5 mg/kg) or vecuronium (0.1 mg/kg) was given and endotracheal intubation was performed after twitch response was depressed more than 80%. Neuromuscular blockade was assessed by train-of-four at the adductor pollicis with supramaximal stimulation of ulnar nerve of 2 Hz every 12 sec. The onset time, duration of 5, 25, 50, 75% recovery time and recovery index were checked. RESULTS: Onset of block was not significantly different among four gorups. Recovery time of 5, 25, 50, 75% and recovery index were longer in the both renal failure groups. Action durations in renal failure were not significantly different between AK and VK groups. CONCLUSION: It is concluded that action duration of atracurium and vecuronium are affected by renal function. We would better monitor muscle relaxation and titrate dose of muscle relaxant.

Action Duration of Atracurium in the Elderly Patients / 대한마취과학회지

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.