Journal: J Clin Anesth 20(4):290-293, 2008
Reprint: Dept of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104-4399 (A Ganesh, MBBS)
Faculty Disclosure: Abstracted by S. Ouellette, who has nothing to disclose.
Etomidate infusion has been used to achieve an iso¬electric electroencephalogram in neurosurgical prac¬tice to decrease both cerebral oxygen consumption and cerebral blood flow. It is thought to maintain hemodynamic stability and help in earlier awakening when used for the same. Hyperosmolar increased-anion-gap metabolic acidosis without hyperglycemia has been reported after infusion of etomidate and other medications containing propylene glycol. Administration of large quantities of propylene glycol causes acute tubular necrosis, hemolysis, and seizures, but hyperglycemia after administration of these agents has not been reported. This article reports a case of this biochemical abnormality with severe hyperglycemia. Cessation of the etomidate infusion along with other supportive measures resulted in prompt resolution of the metabolic acidosis and hyperglycemia.
Etomidate is formulated in propylene glycol, a hyper¬osmolar solvent used to stabilize the agent. Approxi¬mately 45% of absorbed propylene glycol is excreted unchanged by the kidneys, and the remainder is metabolized in the liver by alcohol dehydrogenase to pyruvate, lactate, or acetate. Hepatic and renal insuf¬ficiency may accelerate the development of propyl¬ene glycol toxicity. An association has been observed between increased serum creatinine concentration and duration of lorazepam therapy and it may be due to proximal renal tubular injury caused by propylene glycol. Accumulation of lactic acid is the cause of the increased anion-gap acidosis. The hyperosmolality observed is due to accumulation of propylene glycol, which is a hyperosmolar substance. The osmolar gap correlates well with serum glycol levels.
Stimulation of gluconeogenesis from high pyruvate levels may explain the severe hyperglycemia. One should monitor acid base status, osmolality, and glucose levels when administering prolonged infu¬sions of drugs containing significant amounts of propylene glycol parenterally so as to be able to recognize metabolic derangements early and prevent serious complications. |
