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., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
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].