Kinetic eGFR (Chen 2013)
Estimates GFR while creatinine is still rising or falling, from two creatinine values and the time between them.
Inputs
1 of 5Pre-illness value
Optional. Leave blank to calculate CKD-EPI 2021 from baseline creatinine, age, and sex.
mL/min/1.73 m²
SexUsed by the equation
Needed only when baseline eGFR is blank
Needed only when baseline eGFR is blank
years
Rise expected if GFR were zero
Patient values are shared with every calculator.
When to use
- Acute kidney injury or recovery, when creatinine is changing and steady-state equations (Cockcroft-Gault, CKD-EPI) would mislead.
- Renal dose decisions between two creatinine values drawn hours to a day or more apart.
Pearls and pitfalls
- Estimates GFR during non-steady-state creatinine; it is not a replacement for a steady-state eGFR once creatinine has plateaued.
- The default maximum rise of 1.5 mg/dL per day assumes that zero GFR would raise creatinine that fast. Use a higher value for high creatinine production (large muscle mass, rhabdomyolysis) and a lower value for low muscle mass.
- Baseline creatinine should be a true pre-illness steady-state value. Large fluid shifts dilute creatinine and can overstate kinetic GFR.
- A rise faster than the assumed maximum drives the estimate to zero; a fast fall can push it above baseline during recovery.
Why use
Gives a usable GFR estimate early in AKI and recovery, when creatinine lags behind true filtration.
KeGFR = (SSPCr × eGFRss ÷ MeanPCr) × [1 − (24 × ΔPCr) ÷ (Δt × MaxΔPCr/day)]; MeanPCr = (PCr1 + PCr2) ÷ 2; ΔPCr = PCr2 − PCr1; Δt in hours