Measured serum osmolality is 320 mOsm/kg and calculated osmolality is 290 mOsm/kg. Which interpretation is most appropriate?
1The osmolal gap is 10 mOsm/kg
2The values prove isolated respiratory alkalosis
3The osmolal gap is 30 mOsm/kg and an unmeasured osmole should be considered✓ 정답
4The measured osmolality must always be lower than the calculated value
해설
The osmolal gap is measured minus calculated osmolality: 320 - 290 = 30 mOsm/kg. A substantial positive gap suggests an unmeasured osmotically active substance or a preanalytic or analytic issue.