nephromatic

Nephromatic gives you a choice of two equations to estimate glomerular filtration rate.

MDRD GFR

The MDRD GFR is an estimate of the glomerular filtration rate (GFR) using serum creatinine and demographic factors. It has not been studied extensively in populations that are not white or black. It relies on a stable creatinine and may be less accurate for GFR values above 60.

Nephromatic uses the simplified MDRD equation by Levey, et. al.

eGFR = 186*(0.742 if female)*(1.212 if Black)*creatinine^-1.153*age^-0.203

CKD-EPI GFR

The CKD-EPI GFR is an estimate of the glomerular filtration rate (GFR) using serum creatinine and demographic factors. It is a relatively new equation proposed to be superior to the MDRD GFR equation.

The CKD-EPI equation by Levey, et. al.:

eGFR = 141 x min(Scr/k, 1)^a x max(Scr/k, 1)^-1.209 x 0.993^Age x 1.018 [if female] x 1.159 [if black]

Scr is serum creatinine, k is 0.7 for females and 0.9 for males, a is -0.329 for females and -0.411 for males, min indicates the minimum of Scr/k or 1, and max indicates the maximum of Scr/k or 1.

CKD Staging

Chronic kidney disease (CKD) staging uses the National Kidney Foundation (NKF) staging system for individuals who have known kidney damage.

Recommendations are based on NKF guidelines for patients with CKD and may not be relevant in the acute setting.

References

1. (Levey AS, Greene T, Kusek J, Beck GJ, Group MS: A simplified equation to predict glomerular filtration rate from serum creatinine [Abstract]. J Am Soc Nephrol 11: A0828, 2000).
2. Levey et al. A new equation to estimate glomerular filtration rate. Ann Intern Med (2009) vol. 150 (9) pp. 604-12.