Osmolar Gap (Elevated) Differential Diagnosis
Normal Osmolar Gap: < 15
- Associations: Ingestion of isopropanol +/- inebriation + no anion gap + no metabolic acidosis
- Pathophysiology: Isopropanol is metabolized to acetone.
- Associations: Alcohol ingestion + inebriation + no anion gap (unless AKA present) + no metabolic acidosis (unless AKA present)
- Pathophysiology: It is an alcohol.
- Associations: Antifreeze ingestion/suicide attempt + anion gap metabolic acidosis +/- renal impairment
- Pathophysiology: Ethylene glycol gets metabolized to eventually for glycolic acid and oxalic acid.
- Associations: Ingestion +/- inebriation + no anion gap (if only ingestion)
- Pathophysiology: It is an alcohol and metabolized to acetone.
- Associations: IV infusion of mannitol
- Pathophysiology: An organic substance that absorbs water.
- Associations: Reports of ingestion +/- metabolic acidosis +/- changes in vision
- Pathophysiology: Methanol is metabolized to formic acid.
- Associations: Use of lorazepam (Ativan) or Dilantin infusions
- Pathophysiology: It is an organic substance that absorbs water.
Ethylene Glycol (Antifreeze)