Ethylene glycol poisoning

- commonly used as a coolant and preservative and is found in polishes and detergents

- ethylene glycol poisoning often exhibits three distinct clinical phases after ingestion due to toxic metabolites glycolate, glyoxalate and oxalate

- first 12 hours - CNS effect predominate, patient appears intoxicated

- 12-24 hours - cardiopulmonary effect predominate, tachycardia, tachypnea and raised BP are common

- 24-72 hours - renal effects predominate

- hypocalcemia may result from precipitation of calcium oxalate in tissues and may be severe enough to cause tetany and typical ECG changes

- high anion gap metabolic acidosis

- treatment: gastric lavage within 1 hour of ingestion

- inhibit metabolism with intravenous ethanol (competitive inhibitor of alcohol dehydrogenase). Ethanol requires treatment on the ITU because of risk of respiratory depression

- fomepizole is an alternative treatment, being more potent than ethanol but generally more expensive