Atracurium resistance in a critically Ill patient.
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.
D000328:Adult; D001279:Atracurium / Q000008:administration & dosage*; D016638:Critical Illness; D004351:Drug Resistance; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D009469:Neuromuscular Junction / Q000187:drug effects*; D003473:Neuromuscular Nondepolarizing Agents; D010197:Pancuronium / Q000008:administration & dosage; D018243:Teratocarcinoma / Q000628:therapy; D013736:Testicular Neoplasms / Q000628:therapy
D003473:Neuromuscular Nondepolarizing Agents; D001279:Atracurium; D010197:Pancuronium