Fractional Excretion of Urea (FeUrea)
Better than FENa for distinguishing pre-renal from intrinsic AKI in patients on diuretics.
Score interpretation
FeUrea < 35%: Consistent with pre-renal AKI. More reliable than FENa in patients receiving diuretics.
→ IV fluid resuscitation. Address underlying cause of volume depletion.
FeUrea 35–50%: Indeterminate. Clinical context required.
→ Consider clinical picture, urine microscopy, and response to fluid challenge.
FeUrea > 50%: Consistent with intrinsic renal (tubular) disease.
→ Consider ATN, acute interstitial nephritis. Nephrology review. Stop nephrotoxins.
Interpretation bands for the FeUrea. Apply clinical judgement and local guidance.
References
- Carvounis CP et al. Significance of the fractional excretion of urea in the differential diagnosis of acute renal failure. Kidney Int. 2002.
Related
Curated clinical cross-links plus same-class fallbacks.
- Mannitol (Osmotic Diuretic — Renal/Neurological) · Acute Oliguric Renal Failure / Raised ICP
- Glyceryl Trinitrate (Sublingual / IV) · Nitrate / Acute Angina
- Dobutamine (Acute HF / Stress Echo) · Inotrope / Acute Heart Failure
- Milrinone · Inodilator / Acute Heart Failure
- Prednisolone (Systemic) · Systemic Corticosteroid — Acute Dermatoses
- Emollients, urea-containing · Topical emollient (urea, keratolytic)
- Difficult Airway Algorithm (DAS) · DAS 2015; Royal College of Anaesthetists
- Major Haemorrhage Protocol · NICE NG24; UK MHP guidelines
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
- Ventricular Tachycardia / Fibrillation · Resuscitation Council UK ACLS; ESC 2022 Ventricular Arrhythmia Guidelines
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.