RENAL PHYSIOLOGY-OSMOLAL GAP

SUMMARY

1. The osmolality of the blood is determined mainly by concentrations of Na+, glucose, and urea.

2. The osmolal gap (OG) helps you determine whether unmeasured osmotically active substances (osmoles) are circulating in the blood (and possibly causing an acidosis).

3. High OG, ingestion of substances: methanol, ethylene glycol ingestions and propylene glycol.

4. High OG, other causes: CKD, ketoacidosis, lactic acidosis.

Reference(s)

Wilkinson, I. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].