A Retrospective Analysis of Long‐Term Use of Nondepolarizing Neuromuscular Blocking Agents in the Intensive Care Unit, and Guidelines for Drug Selection

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.

Prolonged Neuromuscular Blockade in Two Critically Ill Patients Treated With Atracurium

Hoey,

Joslin,

Nahum

et al. 1995

Atracurium Resistance in a Critically Ill Patient

Tschida,

Hoey,

Nahum

et al. 1995

A previously healthy 25‐year‐old man with metastatic testicular teratocarcinoma became resistant to atracurium‐induced neuromuscular blockade as evidenced by train‐of‐four (TOF) monitoring combined with clinical assessment. Subsequently he had an adequate response with a standard dosage of pancuronium. During the first 10 days of neuromuscular blockade, the atracurium requirements escalated from 0.31 to 1.7 mg/kg/hour, guided by TOF monitoring, movement, and spontaneous respirations. The infusion was discontinued but later reinstituted. Despite a total atracurium loading dose of 1.4 mg/kg followed by an infusion rate titrated to 1.7 mg/kg/hour, inadequate paralysis persisted. Atracurium was terminated and an intravenous infusion of pancuronium 0.10 mg/kg/hour was started. Over the next 3 days the pancuronium infusion was titrated down to a range of 0.04‐0.06 mg/kg/hour, followed by a maintenance infusion of 0.01‐0.05 mg/kg/hour for 5 days. A pharmacokinetic alteration, such as increased metabolism or elimination, may have caused the atracurium resistance.

The Impact of Practice Guidelines on Prescribing Patterns of Nondepolarizing Neuromuscular Blocking Agents

Tschida,

Hoey,

Vance‐Bryan

1996

Guidelines for selecting nondepolarizing neuromuscular blocking agents (NNMBAs) were developed and implemented by an interdisciplinary team for use in our intensive care units. They suggest pancuronium as the drug of choice if the patient does not have renal insufficiency and is hemodynamically stable. If either of these criteria is not met and hepatic function is normal, vecuronium is recommended. Atracurium is reserved for patients not meeting either criterion. A 12‐month retrospective chart review was performed for 24 patients 18 years of age or older who received continuous infusion of an NNMBA beginning 7 months after the guidelines were implemented. Before the guidelines, atracurium, vecuronium, and pancuronium were prescribed for 68% (17), 24% (6), and 8% (2) of patients, respectively. Their use was inappropriate based on organ function and hemodynamic stability in 88% (15), 83% (5), and 0% of patients, respectively. After guideline implementation, atracurium, vecuronium, and pancuronium were prescribed for 33% (8), 21% (5), and 46% (11) of patients, respectively, and use was inappropriate in 38% (3), 60% (3), and 0% of patients, respectively. Overall, the prevalence of inappropriate NNMBA selection decreased from 80% (20) to 25% (6). Further analysis is necessary to determine the associated pharmacoeconomic impact of decreased inappropriate NNMBA prescribing.