Health & Medical
FENa Calculator
Calculate Fractional Excretion of Sodium to differentiate Prerenal Azotemia from Acute Tubular Necrosis (ATN).
Lab Inputs
Diagnostic Result
FENa Score
--%
Waiting for data...
Prerenal (<1%)
Maybe
ATN (>2%)
Enter serum and urine values to see the clinical interpretation.
Interpretation
- < 1% (Prerenal) Kidneys conserving Na
- > 2% (Intrinsic) Acute Tubular Necrosis
- 1% - 2% Indeterminate
Formula Used
FENa
=
(UNa × PCr)
(PNa × UCr)
× 100
Note: Not valid if patient is on diuretics. Only use in oliguric AKI.