News and Updates

Estimated Glomerular Filtration Rate (eGFR)

07/14/2006
TO: Regional Medical Laboratory Clients
FROM: William F. Fitter, M.D., Chief of Clinical Chemistry, and
Jeanette Parker, MT(ASCP), Manager of Clinical Chemistry
DATE: July 14, 2006
SUBJECT: Estimated Glomerular Filtration Rate (eGFR)

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SUMMARY
Routine estimation of Glomerular Filtration Rate from serum creatinine has been advocated as an important tool for the early recognition of decreased renal function in adults. Effective August 7, 2006, Regional Medical Laboratory will calculate and report estimated Glomerular Filtration Rate (eGFR), on all outpatients, using the MDRD prediction equation, with each measured serum creatinine and submitted patient demographic data.

BACKGROUND
The incidence of both early and end-stage renal disease is rising and is often under-diagnosed and under-treated. Early detection of decreased renal function can help delay or prevent adverse outcomes by allowing earlier treatment that may be effective in slowing disease progression or reducing factors associated with cardiovascular disease and diabetes mellitus.

The National Kidney Disease Education Program (NKDEP) of the NIH and guidelines set forth by the Kidney Disease Outcome Quality Initiative (K/DOQI) of the National Kidney Foundation advocate routinely estimating Glomerular Filtration Rate (eGFR) from serum creatinine, which provides results comparable or superior to traditional urine creatinine clearance methodology.

For adults the NKDEP recommends use of the MDRD (Modification of Diet in Renal Disease) prediction equation for calculation of eGFR where:

eGFR(mL/min/1.73m2) = 186 x (Pcreatinine)-1.154 x (Age)-0.203 x (0.742 if Female) x (1.21 if African American)

INTERPRETATION STAGE DESCRIPTION eGFR(ml/min/1.73m2)
1-2 Normal GFR >=60
3 Moderately decreased GFR 30-59
4 Severely decreased GFR 15-29
5 Kidney failure <15 (or dialysis)

 

ORDERING AND REPORTING INFORMATION
Calculated GFR will be routinely reported on all outpatients unless requested otherwise through Client Services.
MDRD calculations require the patient’s age, gender and race. While age and gender are usually available from the laboratory requisition, race is often not. Accordingly, RML will report eGFR values for both an African American (GFR AA) and Non-African American (GFR NON-AA) so that the physician or patient can decide which is appropriate. Patient’s height and weight is not needed.

CONTACT US
RML Client Services 918.744.2553
William F Fitter M.D. 918.744.2553 wfitter@sjmc.org
Jeanette Parker, Manager, Chemistry 918.744.2553 jparker@sjmc.org