Nephrology Equation Limited evidence Clinical review pending v1.0.0

Fractional Excretion of Urea (FEUrea)

Is AKI prerenal in a patient receiving diuretics?

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About this tool

Percentage of filtered urea excreted, less affected by diuretics than FENa.

Intended use

Adults with AKI, particularly when diuretics have been given.

Outcome

Physiological classification of AKI

Time horizon

Point in time

Derivation population

Adult AKI cohort (Carvounis 2002).

Limitations

Lower accuracy in sepsis, older adults and osmotic diuresis.

Clinical problems

Kidney function and AKI

Evidence

Evidence level

Limited evidence

Derivation and limited validation only, or significant known calibration problems. Methodology

Evidence summaries for this tool are awaiting independent clinical review. Statistics are shown only where they could be attributed to a specific publication.

References

Original publicationCarvounis CP, Nisar S, Guro-Razuman S. Significance of the fractional excretion of urea in the differential diagnosis of acute renal failure. Kidney Int 2002;62:2223-2229. Find on PubMed (opens in a new tab)

Version history

Version	Formula	Effective	Reviewer	Changes
v1.0.0	Carvounis 2002	2026-10-03	—	Initial implementation with reference test vectors.

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Clinical decision support only. Interpret results in the context of the individual patient and current guidance; HumanPulse does not replace professional medical judgment.