How to calculate glomerular filtration rate (GFR)

Glomerular filtration rate (GFR) is a laboratory value that evaluates kidney function. Although you possibly can recognize a GFR result simply from a lab printout, it is crucial to do not forget that this result is predicated on calculations that include serum creatinine, age and gender. There are several estimating equations and even online calculators; The American Society of Nephrology and the National Kidney Foundation recommend the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

CKD-EPI equation (Inker and Perrone, 2021)

This equation not features a race factor and should end in underestimation of GFR in black patients and overestimation of GFR in others. This equation was developed to more accurately estimate GFR in individuals with normal or barely reduced GFR (above 60 ml/min/1.73 m²) and will only be utilized in patients with stable renal function. Please note that eGFR equations that include creatinine will probably be less accurate in individuals who have aspects that influence serum creatinine, comparable to high or low muscle mass or creatinine intake, cirrhosis, chronic heart failure, amputations, -muscular or in patients with a high-protein or vegetarian weight loss program. Confirmatory testing could also be required, including each a cystatin C and creatinine test and a timed urine collection to envision creatinine clearance.

Inker, L. A., & Perrone, R. D. (2021, October 4). Assessment of kidney function. Current. https://www.uptodate.com/contents/assessment-of-kidney-function

Levey, A. S., and Inker, L. A. (2018). Definition and severity of chronic kidney disease in adults. Current. Downloaded from https://www.uptodate.com/contents/definition-and-staging-of-chronic-kidney-disease-in-adults