Calculated osmolality and osmolal gap
Calculated serum osmolality and the gap versus measured, for toxic alcohols.
Inputs
0 of 3mEq/L
Optional
mg/dL
Optional
mOsm/kg
When to use
- Suspected toxic alcohol ingestion.
- Unexplained high anion gap acidosis.
Pearls and pitfalls
- A normal gap does not exclude toxic alcohol ingestion, especially late.
- Ethanol divisor of 3.7 is commonly used; some sources use 4.6.
Why use
Includes ethanol so the gap is not falsely raised.
- where
- Na
- Sodium, mEq/L
- Glu
- Glucose, mg/dL
- BUN
- Blood urea nitrogen, mg/dL
- EtOH
- Ethanol, mg/dL