At our hospital physicians are asking for an Estimated Creatinine Clearance by calculation from weight for every blood sample that a Creatinine is ordered. Knowing that this estimation can be inaccurate I am wondering if other labs have heard requests for this and what solutions have worked well. I have heard of the Cystatin C test that seems like a better way to monitor GFR in general.   

CKD is a world wide public health problem. Adverse outcomes of CKD include loss of kidney function, sometimes leading to kidney failure, and cardiovascular disease (CVD). Some of the adverse outcomes of CKD can be prevented or delayed by early diagnosis and treatment. Unfortunately, CKD is under-diagnosed and under-treated. As a step toward improvement of this health care problem, NKDEP and KDOQI advocate routine reporting by laboratories of GFR estimates with serum creatinine.

At our hospital physicians are asking for an Estimated Creatinine Clearance by calculation from weight for every blood sample that a Creatinine is ordered. Knowing that this estimation can be inaccurate I am wondering if other labs have heard requests for this and what solutions have worked well. I have heard of the Cystatin C test that seems like a better way to monitor GFR in general.   

I have almost 10 years of clinical laboratory experience in the renal dialysis field. While many question the validity of the estimated GFR, if your doctors want it, it was actually best described in the Sept. 2004 issue of Advance magazine. I am including an excerpt from their very excellent article below ....

'The MDRD equation for estimating GFR is as follows:

GFR (mL/min/1.73 m2) = 186 x (P_cr )-1.154 x (age)-0.203 x (0.742 if female) x (1.210 if African American).

Note that Pcr is serum creatinine in mg/dL, and age is expressed in years.

The NKDEP currently recommends that labs report values above 60 mL/min/1.73 m2 merely as 'above 60 mL/min/1.73 m2' rather than report an exact number. For values below 60 mL/min/1.73 m2, the report should give the numerical estimate. Quantification of GFR below 60 mL/min/1.73 m2 has more clinical implications than it does above that level. This is recommended because the equation has been most extensively evaluated in people with some degree of renal insufficiency.'

I also worked out a simple program in Excel to calculate it - if you need it, e-mail me and I will be glad to e-mail you a copy. Hope this helps ....

I am intrested in evalaution of GFR for purpose of adjusting the drugs such as gentamicin

Iam in need for an EXcel Program for estimation of GFR by MDRD

currntly I am using C &G equation

my Email Ahmedshaker21@yahoo.com

I am intrested in your program , pls send a copy

I developed a program using C&G equation but programing is time consuming

thank yoy

I hope you received the Excel program. One thing I discovered when trying to build it was that (due to possible limitations in formatting) the formula does not clearly indicate that the '-1.154' and the '-0.203' are actually log functions:

GFR (mL/min/1.73 m2) = 186 x (P_cr )^-1.154 x (age)^-0.203 x (0.742 if female) x (1.210 if African American).

For anyone interested, I am posting the NIH website to use as a reference, and it also contains a GFR calculator that can be used to check your work - or to use as needed. Hope this helps .... Jd

JoAnne,

I would like a copy of your Excel program for calculating GFR. 

One of my doctors asked about this last year.  Our problem is creating the test with calculation in our LIS.  We can certainly program the calculation; however, we can program age-related reference ranges but not race-related reference ranges.  Since our results reports are formatted in columnar format with the last 4 encounters in columns across the page, including a table is not feasible due to space limitations.  How do you report the GFR?

thanks, Kathy Zachry    kzachry@fdc.org

Some of our physicians are requesting Estimated Creatinine Clearance instead of GFR---they say it is a better indication of renal function. Is this true only in certain age groups or is it not true??  Thanks for any information