Prolonged weakness after cisatracurium infusion: A case report

Objective: To present the first documented case report of myopathy persisting far >48 hrs in a patient treated with cisatracurium and concomitant high-dose corticosteroids. Design: Anecdotal observations in one patient. Setting: Medical-respiratory intensive care unit (ICU) at a tertiary care, university teaching hospital. Patient: A 45-yr-old female admitted status for post-bilateral total knee replacement complicated by aspiration pneumonitis and acute respiratory distress syndrome (ARDS). Interventions: The patient required pressure control ventilation and sedation with midazolam and fentanyl infusions. On ICU day 2, the patient was placed on inverse ratio ventilation and paralyzed with cisatracurium. On ICU day 6, methylprednisolone 125 mg iv every 6 hrs was initiated for fibroproliferative ARDS. On ICU day 11, methylprednisolone was reduced to 60 mg iv every 6 hrs and tapered over several weeks. Cisatracurium infusion rates ranged from 6.3 to 10.5 mu g/kg/min, with an average of 8.0 mu g/kg/min. Measurements and Main Results: Train-of-Four was assessed before initiation of therapy and every 4 hrs, thereafter. Train-of-Four values were maintained from 1 to 4 throughout therapy and a value of 4 was recorded when therapy was discontinued. On day 13, neuromuscular blocking agent therapy was discontinued, but severe proximal and distal muscle weakness was observed bilaterally. Creatinine kinase concentrations on 3 and 13 days after discontinuation of the paralytic agent were 181 and 96 units/L, respectively. On day 24, the patient moved her fingertips. On ICU day 30, the patient was weaned from the mechanical ventilator. The patient was transferred to the ward on day 33. Extensive rehabilitation with physical and occupational therapy was required for several months. Conclusion: Clinicians should remember that irrespective of chemical structural, neuromuscular blocking agents might produce prolonged paralysis in predisposed patients.