2025 – PAGE 206 – EMERGENCY MEDICINE & TOXICOLOGY

ETHYLENE GLYCOL INGESTION

Ethylene Glycol is the really bad one. It is found in ANTIFREEZE. Urine fluoresces with a Woods lamp and has CALCIUM OXALATE CRYSTALS on microscopy. There is a POSITIVE ANION GAP. Ingestion can result in HYPOCALCEMIA. Symptoms include tachycardia, HTN, and eventually cardiorespiratory failure from acidosis and hypocalcemia. It will also eventually result in renal failure. Treat with ethanol, fomepizole, or emergent hemodialysis.

• PEARL: Its presentation can look just like alcohol, so look for clues such as “playing in the garage,” or a picture of calcium oxalate crystals. Also, the Osmolar Gap (OG) is VERY high (> 20). Normal is < 10 mOsm/kg. OG = Measured – Calculated Osmolality.
• MNEMONICS: For a problem this bad, it’s okay to give a kid ETHANOL for treatment. When you see the words ethylene glycol, think ethXlene glXcol to remind you of the calcium oxalate crystals in the urine. Regarding the images, this could get a little confusing, so also imagine an X on a long can of beer to remember that the crystals associated with ethylene glycol are tubular in shape. Regarding the hypocalcemia, assume it’s from the loss of the calcium in the calcium oxalate crystals!
• (DOUBLE TAKE) CALCIUM OXALATE CRYSTALS: Calcium oxalate stones are the most common ones in humans. There are two types of calcium oxalate crystals. One is square and looks like it has an X on it. That one is very common. The other is elongated and looks like a rod. The long one is the one usually associated with ethylene glycol poisoning.
  • IMAGE: www.pbrlinks.com/CALCIUMOXYLATE1
    • MNEMONIC: calcium oXalate crystals look like a big X on a crystal.
  • IMAGE: www.pbrlinks.com/CALCIUMOXYLATE2 (This one is related to ethylene glycol and kind of looks like a long can of beer, or needles.)

ISOPROPYL ALCOHOL

Isopropyl alcohol ingestion results in a positive ETHANOL reading on toxicology screens. Alcohol dehydrogenase breaks it down into ACETONE (SO KETONES WILL BE PRESENT). This is found in mouthwash and rubbing alcohol and is used as an alcohol substitute for its intoxicating effects. It is mainly a CNS depressant. The patient’s breath may have a fruity odor from the acetone.

PEARL: There is NO anion gap. If alcohol is positive and there is NO anion gap, choose ISOPROPYL ALCOHOL poisoning. If an anion gap is PRESENT, choose ETHANOL, METHANOL, or ETHYLENE GLYCOL. This is not intuitive, given the presence of ketones, but knowing this could be key.

PEARL/SHORTCUT: Osmolar gaps (AKA osmolal gaps) are present in ALL of the alcohols discussed (ethanol, methanol, ethylene glycol, and isopropyl alcohol). Anion gaps can also present in ALL of them EXCEPT FOR ISOPROPYL ALCOHOL INGESTION! For ethanol ingestion, an anion gap acidosis can eventually be present, but is more common in alcoholics and with very heavy alcohol use resulting in starvation-related ketoacidosis.

STIMULANTS

The most common stimulants you may be tested on include amphetamines and cocaine.

AMPHETAMINES

Amphetamines may cause HYPERTENSION, EUPHORIA, agitation, arrhythmias, psychosis, and seizures. Treatment is supportive.