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Related to osmolal gap: osmolar gap
a difference between the observed and calculated osmolalities in serum analysis. The calculated osmolar values include sodium concentration multiplied by 2, plus glucose and blood urea nitrogen.
The difference between the measured osmolality of the plasma, and the calculated osmolality of the plasma (plasma glucose/18 + blood urea nitrogen/2.8 + sodium*2). A gap is present when the difference exceeds 10 mmol/kg of water. Osmolal gaps are present when unmeasured osmotically active solutes, such as toxins, e.g., methanol or ethylene glycol, are present in the plasma.
See also: gap
adjectival form of mole, a one osmolal solution contains 1 mole of solute in 1 L of water.
difference between the measured plasma osmolality and the osmolality calculated from the plasma concentration of normally measured solutes.