Prolonged neuromuscular blockade in two critically ill patients treated with atracurium

Recent literature suggests that the risk of prolonged neuromuscular blockade associated with atracurium compared with other nondepolarizing neuromuscular blocking agents may be minimal. Two patients experienced prolonged weakness associated with the administration of atracurium. Both received atracurium 0.5-0.7 mg/kg/hour in combination with methylprednisolone 500-600 mg/day. Electromyographic results and creatine kinase levels were suggestive of muscular weakness in both patients. Despite high-dose corticosteroid therapy, the electromyographic evidence supporting prolonged weakness did not suggest typical corticosteroid myopathy. Although some clinicians advocate routine administration of atracurium in critically ill patients due to the relative lack of reports of prolonged weakness, this may be premature. Although there are fewer reports of atracurium-associated prolonged weakness compared with pancuronium and vecuronium, the patients we describe suggest that it may occur.