RENAL PHYSIOLOGY-GFR

SUMMARY

1. Glomerular filtration rate (GFR) is a measure of overall renal function.

2. Creatinine clearance is used to estimate GFR.

3. Creatinine is released from skeletal muscle at a fairly constant rate and is not filtered entirely by the glomerulus.

4. The Cockcroft-Gault formula: [(140 - age) x (Wt) x (0.85 if female)] / (72 x serum Cr)

5. Both the MDRD and Cockcroft-Gault equations are less accurate in populations with normal or near-normal GFR.

6. Estimation equations for GFR are not very accurate when there is an extreme of age and weight and in patients with amputations, cirrhosis, or pregnancy.

7. In these situations, collect a 24-hour urine to estimate GFR

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].