WHAT IS OSMOLALITY CALCULATED TEST (OSMOLAR GAP)?
Osmolality refers to a solution’s concentration of solute particles per kilogram of solvent and is expressed in milliosmoles per kilogram (mOsm/kg). In the laboratory, it is measured by an osmometer. However, it is possible to calculate serum osmolality using serum measurements of sodium, glucose, and urea (BUN) according to the formulas listed under Procedure. The osmolar gap is the difference between the laboratory serum osmolarity value and the calculated osmolar value. Assessing this gap is most important in the diagnosis of ethyl alcohol (ethanol) or methanol poisoning.