Ethylene glycol poisoning as a cause of severe high–anion gap metabolic acidosis: a case report and therapeutic approach in intensive care

Severe high-anion gap metabolic acidosis is a medical emergency in the Intensive Care Unit and is associated with high morbidity and mortality. Ethylene glycol poisoning is an uncommon but potentially fatal cause, often diagnosed late and challenging to manage, particularly in settings with limited access to specific antidotes. We report the case of an 18-year-old female patient with a history of autism spectrum disorder and moderate intellectual disability who was admitted to the Intensive Care Unit 24 hours after accidental ingestion of ethylene glycol. The patient developed toxic-metabolic encephalopathy and severe high–anion gap metabolic acidosis (pH 6.99; HCO₃⁻ 2-3 mEq/L), accompanied by critical hyperkalemia and acute kidney injury (KDIGO stage 3). In the absence of specific antidotes, advanced life support and urgent hemodialysis through serial sessions were initiated, resulting in rapid correction of metabolic disturbances, full recovery of renal function, and a favorable clinical outcome. This case highlights the importance of systematic acid–base assessment and early hemodialysis as key strategies to improve outcomes in ethylene glycol poisoning.