eGFR Calculator CKD EPI Equation

CKD-EPI Equation:

\[ eGFR = 142 \times \min(Scr/\kappa, 1)^\alpha \times \max(Scr/\kappa, 1)^{-1.200} \times 0.9938^{age} \times (1.012 \text{ if female}) \]

Estimated GFR (eGFR):

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1. What Is The eGFR Calculator CKD EPI Equation?

The eGFR Calculator CKD EPI Equation estimates glomerular filtration rate (GFR) from serum creatinine, age, and sex using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) formula. This equation provides a more accurate assessment of kidney function compared to older methods.

2. How Does The Calculator Work?

The calculator uses the CKD-EPI equation:

\[ eGFR = 142 \times \min(Scr/\kappa, 1)^\alpha \times \max(Scr/\kappa, 1)^{-1.200} \times 0.9938^{age} \times (1.012 \text{ if female}) \]

Where:

\( Scr \) — Serum creatinine (mg/dL)
\( \kappa \) — 0.7 (female) or 0.9 (male)
\( \alpha \) — -0.241 (female) or -0.302 (male)
\( age \) — Age in years
1.012 — Female multiplier

Explanation: The equation accounts for the non-linear relationship between creatinine and GFR, with different coefficients for different demographic groups.

3. Importance Of eGFR Calculation

Details: Accurate GFR estimation is crucial for diagnosing chronic kidney disease, determining disease stage, and guiding medication dosing decisions.

4. Using The Calculator

Tips: Enter serum creatinine in mg/dL, age in years, and select gender. All values must be valid (creatinine > 0, age between 1-120 years).

5. Frequently Asked Questions (FAQ)

Q1: What Is The Difference Between This Equation And Other eGFR Formulas?
A: This CKD-EPI equation uses updated coefficients (142, -1.200, 0.9938) that provide improved accuracy across different GFR ranges compared to older versions.

Q2: What Are Normal eGFR Values?
A: Normal eGFR is generally ≥90 mL/min/1.73m², though values naturally decline with age. Values below 60 for 3+ months indicate chronic kidney disease.

Q3: When Should Creatinine Be Measured For Accurate Results?
A: Morning fasting samples are ideal, but random samples are acceptable. Avoid testing after meat-heavy meals or vigorous exercise.

Q4: Are There Limitations To This Equation?
A: The equation may be less accurate in extremes of age and weight, amputees, pregnant women, and those with rapidly changing kidney function.

Q5: Can This Calculator Be Used For Drug Dosing Decisions?
A: For precise drug dosing, measured GFR (e.g., via iohexol clearance) may be needed in certain high-risk populations.