Review Question - QID 102976

This man presents to the emergency department with confusion, ataxia, labs significant for anion gap metabolic acidosis and calcium oxalate crystals on his urinalysis in the setting of homelessness. This is most likely an acute case ethylene glycol intoxication and should be treated with fomepizole (first-line treatment).

The man's history of previous alcohol intoxication along with new homelessness should concern us of intoxication with another substance. Alcohol would be possible, but one must consider other ingestions if this patient cannot afford alcohol. Ethylene glycol, an ingredient found in antifreeze and various other cleaning products, is a commonly ingested substance due to its sweet taste and effects similar to alcohol. Patients commonly present with similar symptoms to alcohol intoxication: confusion, ataxia, irritation, and slurred speech.

Figure A shows a urinalysis with calcium oxalate crystals often described as "envelope" shaped.

Incorrect Answers:
Answer 1: Fomepizole is a better alternative than ethanol for ethylene glycol toxicity as noted above.
Answer 2 and 3: Naltrexone and Naloxone are both used for opiate overdose with Naloxone used in the acute setting in an IV form and Naltrexone used over the long term because of it's long half-life in a PO form.
Answer 4: Flumazenil is an antidote for benzodiazepene overdose. It's use can cause withdrawal seizures in patients, so it is usually only used in critical condition patients. Otherwise, most patients are placed on a long benzodiazepene taper and behavioral therapy.