Propylene glycol toxicity caused by prolonged infusion of etomidate.

We describe a case of propylene glycol toxicity due to intravenous administration of etomidate for cerebral protection. A continuous etomidate infusion was titrated to burst suppression of the electroencephalogram during surgical resection of a large intracranial arteriovenous malformation. The etomidate formulation used (Amidate, Abbot) contains etomidate 2 mg/ml in a 35% propylene glycol vehicle. A total of 5 g/kg of the solvent was given during 12 h. Adverse effects of propylene glycol were observed including hyperosmolality with an increased osmolal gap, hemolysis, hemoglobinuria, and metabolic acidosis. Normalization of these metabolic and ionic alterations occurred after 12 h of discontinuation of the infusion. The potential toxicity of the solvent should be considered during long-term administration of etomidate.