This version was machine-translated from German and has not been medically reviewed. The authoritative version is the German version.
FENa – fractional sodium excretion
Prerenal (< 1 %) or intrinsic (≥ 3 %)? From sodium and creatinine in urine and serum
Calculation aid for healthcare professionals: the calculator reproduces what the sources cited assign to the inputs. Clinical assessment and every treatment decision remain with the treating physician. Inputs and results are not stored.
Frequently asked questions
FENa – fractional sodium excretion: What does this calculator compute?
Calculates the fractional excretion of sodium (FENa = U-Na × P-creat / (P-Na × U-creat) × 100) to distinguish prerenal kidney failure (< 1 %) from acute tubular necrosis (≥ 3 %; Espinel 1976) – with a note on the different limits in newborns.
FENa – fractional sodium excretion: Which sources is this calculator based on?
Espinel CH: The FENa test. Use in the differential diagnosis of acute renal failure (JAMA 236:579–581) (1976)