Nephrology Free

Serum Osmolality

Calculated serum osmolality.

Enter Values

Sodium (mEq/L)

Range: 100 - 180

Glucose (mg/dL)

Range: 20 - 2000

BUN (mg/dL)

Range: 1 - 200

Score

Author Classical laboratory formula

Evidence Standard clinical practice

Category Nephrology

Original Study Osm = 2(Na) + Glucose/18 + BUN/2.8

About Calculated serum osmolality, compared to measured osmolality, yields the osmolar gap used to detect toxic alcohols or other unmeasured osmoles.

Clinical Use Suspected methanol, ethylene glycol, or isopropyl alcohol ingestion.