Estimated glomerular filtration rate

The following are used by a laboratory to calculate an estimated glomerular filtration rate EXCEPT for which one?

a) Age

b) Weight

c) Ethnic group

d) Local variations in serum creatinine measurement

e) Gender

Answer: b

Explanation

Estimated glomerular filtration rate (eGFR) has become the standard value used to quantify renal function. It is used to define a patient’s degree of chronic kidney disease and in the calculation of nephrotoxic drug doses. eGFR can be calculated by the clinician by visiting online calculators, entering the patient’s serum creatinine measurement and details of gender, age and ethnicity. A more accurate estimate is obtained by local laboratories who also take into consideration variations in measurement experienced within the local laboratory. It is still only an estimate and the standard formula for calculation is not accurate for children, pregnant women and people at the extremes of body habitus such as the malnourished or Class III obesity.

Reference

The Renal Association. eGFR calculator. Online at www.renal.org/eGFRcalc/GFR.pl

(Accessed 30 October 2009)