Fractional Excretion of Urea
Identify a pre-renal state in patients using diuretics
A fractional excretion of urea (FEUrea) of < 35% is suggestive of pre-renal azotemia. Unlike when measuring of the fractional excretion of sodium, (FENa), it can be used even when patients are taking diuretics.
Fractional Exceretion of Urea = Uur X Pcreat / Ucreat X Pur · 100%
- Uur = Urine urea
- Pcreat = Plasma creatinine
- Ucreat = Urine creatinine
- Pur = Plasma urea
Carvounis et al.