Serum osmolarity and osmolar gap
Calculates plasma osmolarity from sodium, glucose and urea; with measured osmolality, the osmolar gap helps detect toxic alcohols and other unmeasured solutes.
Calculate with transparency
Check the population, units and version. The result shows the formula or classification; it does not make an automatic treatment decision.
Preparing the form…
- Check the method
- Enter the data
- Check the result
Method · Limits of application
2 Na+glucose/18+urea/6 or BUN/2.8; ethanol/Purssell 2001 /3.7; tonicity excludes urea
The osmolar gap is a clue, not specific identification of an alcohol. Its value depends on metabolic stage, baseline gap and other solutes; ketoacidosis, renal dysfunction and lactic acidosis can also raise it. The formula, units and measured osmolality must match the source; the result alone neither confirms nor excludes poisoning.
Conditions of use
Check the population, units, inclusion and exclusion criteria, and version in the original source. A result alone does not establish a diagnosis, discharge decision or prescription.
Documented parameters
- Sodium · mEq/L
- Glucose · mg/dL
- Urea · mg/dL
- Serum ethanol · mg/dL
- Measured osmolality · mOsm/kg
4/4 reference cases checked. Numerical tests are not clinical validation.
Relationship with cancer research
General context — relationship to be defined
A resource for general clinical contexts. This edition does not assign a specific oncological relationship; selecting it for a study requires a justified question, population and purpose.