American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the recommended treatment for ethylene glycol overdose?

1. Oral activated charcoal

2. Sodium bicarbonate, fomepizole, and hemodialysis

3. Intravenous fluids only

4. Supportive care without specific treatment

The correct answer is: Sodium bicarbonate, fomepizole, and hemodialysis

The recommended treatment for ethylene glycol overdose involves a combination of sodium bicarbonate, fomepizole, and hemodialysis. Each of these components plays a crucial role in managing the toxic effects of ethylene glycol. Fomepizole is an alcohol dehydrogenase inhibitor, which prevents the metabolism of ethylene glycol into its toxic metabolites, specifically glycolic acid and oxalic acid. By inhibiting this enzyme, fomepizole reduces the formation of these harmful byproducts, thus decreasing the severity of metabolic acidosis and potential renal damage. Sodium bicarbonate is used to correct metabolic acidosis that typically occurs with ethylene glycol toxicity. It helps to buffer the acidity in the blood, which mitigates the harmful effects of the acidosis on various organ systems. In cases of severe toxicity or when patients present with significant renal impairment or neurological symptoms, hemodialysis is employed. Hemodialysis is effective in rapidly removing ethylene glycol and its toxic metabolites from the bloodstream, restoring normal acid-base balance and improving the overall prognosis. Combined, these treatments address both the toxicological and physiological effects of ethylene glycol overdose, making the approach comprehensive and aligned with clinical guidelines.