Fractional excretion of sodium (FENa)
Separates prerenal from intrinsic acute kidney injury.
Inputs
0 of 4mEq/L
mEq/L
Plasma creatinine
Patient values are shared with every calculator.
When to use
- Oliguric acute kidney injury.
Pearls and pitfalls
- Unreliable after diuretics; use FEUrea instead.
- Can be low in contrast nephropathy, early obstruction, and rhabdomyolysis.
Why use
A quick bedside discriminator with the arithmetic shown.
- where
- UNa, PNa
- Urine and plasma sodium, mEq/L
- UCr, PCr
- Urine and plasma creatinine, mg/dL