PROLONGED WEAKNESS AFTER LONG-TERM INFUSION OF VECURONIUM BROMIDE

Neuromuscular blocking agents, increasingly used in intensive care units, have been retrospectively reported to cause weakness after prolonged use. This study prospectively compared ten patients with respiratory failure requiring prolonged muscle relaxation using vecuronium and 18 asthmatic patients with respiratory failure requiring mechanical ventilation without vecuronium. Serial neurologic and electrodiagnostic studies were done. Seven of ten patients (70%; 95% CI, 35% to 93%) experienced weakness 24 hours after discontinuation of vecuronium. The weakness was due to prolonged neuromuscular blockade for up to 3 days in two patients and to polyneuropathy characterized by weakness of all extremities, loss of tendon reflexes, and muscle atrophy lasting 5 days to 6 months in five patients. The only factors that correlated with the development of polyneuropathy were the dose (P = 0.047) and duration (P = 0.047) of vecuronium use, None of the control patients with asthma developed weakness. Caution must be exercised when using large doses of vecuronium for a prolonged period.