Fractional Excretion of Urea (FEUrea)

id

62

full_title

Fractional Excretion of Urea (FEUrea)

short_title

FEUrea

med_description

Determines the cause of renal failure. Similar to the FENa, but can be used on patients on diuretics.

description

The Fractional Excretion of Urea (FEUrea) determines the cause of renal failure. Similar to the FENa, but can be used on patients on diuretics.

keywords

Fractional Excretion of Urea (FEUrea), FEUrea, urea calc, urea fraction, urea percentage, urea %, fraction urea, fraction extretion urea, fe urea, esrd feurea, esrf, feurea, esrf urea, esrd urea, diuretics fe, diuretics fe calc, diuretics fe score, diuretics fe percentage, diuretics fractional, diuretics fractional excretion, diuretics fractional urea, diuretics fractional urea calc, diuretics fractional urea score, diuretics fractional calc, diuretics fractional urea mdcalc. diuretics fractional excretion calc, diuretics fractional excretions score, diuretics fractional excretions

complaint

[ "AMS", "Dizziness", "Weakness" ]

formula

Fractional Excretion of Urea (FEUrea) = (Serum_Cr * U_Urea) / (Serum_Urea x U_Cr) %

evidence

measurements

[ { "name": "Creatinine", "unit": "cr", "error_min": "0.01", "error_max": "40", "warn_min": "0", "warn_max": "10", "conversion": "88.4", "normal_max_si": "115", "normal_max_us": "1.3", "normal_min_si": "62", "normal_min_us": "0.7", "units_si": "µmol/L", "units_us": "mg/dL" }, { "name": "Urine Urea", "unit": "urea_urine", "error_min": "0", "error_max": "1800", "warn_min": "1", "warn_max": "700", "conversion": "0.357", "normal_max_si": "250", "normal_max_us": "700", "normal_min_si": "125", "normal_min_us": "350", "units_si": "mmol/L", "units_us": "mg/dL" }, { "name": "Urine Creatinine", "unit": "cr_urine", "error_min": "0", "error_max": "700", "warn_min": "1", "warn_max": "450", "conversion": "88.4", "normal_max_si": "32708", "normal_max_us": "370", "normal_min_si": "1768", "normal_min_us": "20", "units_si": "µmol/L", "units_us": "mg/dL" }, { "name": "BUN", "unit": "bun", "error_min": "1", "error_max": "500", "warn_min": "2", "warn_max": "300", "conversion": "0.357", "normal_max_si": "7.1", "normal_max_us": "20", "normal_min_si": "2.9", "normal_min_us": "8", "units_si": "mmol/L", "units_us": "mg/dL" } ]

information

This test can provide similar information to the FENa equation, but can still be used in patients on diuretic therapy (diuretics alter the sodium concentration, making the FENa equation unusable).

refrences

{ "Clinical Practice Guidelines": [], "Manufacturer Website": [], "Original/Primary Reference": [ { "href": "https://www.ncbi.nlm.nih.gov/pubmed/1415365", "text": "Kaplan AA, Kohn OF. Fractional excretion of urea as a guide to renal dysfunction. Am J Nephrol. 1992;12(1-2):49-54." } ], "Other References": [], "Outcomes": [], "Validation": [ { "href": "https://www.ncbi.nlm.nih.gov/pubmed/12427149", "text": "Carvounis 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(6):2223-2229." }, { "href": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3387621", "text": "Darmon M, Vincent F, Dellamonica J, et al. Diagnostic performance of fractional excretion of urea in the evaluation of critically ill patients with acute kidney injury: a multicenter cohort study. Critical Care 2011;15(4):R178." } ], "Validations": [] }

pearls

While lesser known than FENa, the FEUrea can be used in patients on diuretics, since urea excretion is not significantly affected by diuretics.

usecase

reasons

next_advice

next_actions

next_management

In patients with acute kidney and suspected obstructive uropathy, consider bedside ultrasound to evaluate for hydronephrosis, bladder distention, etc. Empiric Foley catheter placement may also be valid in some settings, though it may also be associated with complications, and does not rule out ureteral obstructions above the bladder.

diseases

[ "Acid-Base Disturbance", "Acute Kidney Injury", "CHF", "Renal Failure" ]

instructions

published

2022-04-21T20:29:44.650Z

purpose

[ "Formula", "Diagnosis" ]

search_terms

[ "renal", "aki", "arf", "fena", "feurea", "urea", "excretion", "fractional" ]

seo

{ "keywords_en": "Fractional Excretion of Urea (FEUrea), FEUrea, urea calc, urea fraction, urea percentage, urea %, fraction urea, fraction extretion urea, fe urea, esrd feurea, esrf, feurea, esrf urea, esrd urea, diuretics fe, diuretics fe calc, diuretics fe score, diuretics fe percentage, diuretics fractional, diuretics fractional excretion, diuretics fractional urea, diuretics fractional urea calc, diuretics fractional urea score, diuretics fractional calc, diuretics fractional urea mdcalc. diuretics fractional excretion calc, diuretics fractional excretions score, diuretics fractional excretions", "meta_description_en": "The Fractional Excretion of Urea (FEUrea) determines the cause of renal failure. Similar to the FENa, but can be used on patients on diuretics." }

specialty

[ "Critical Care", "Emergency Medicine", "Family Practice", "Geriatrics", "Hospitalist Medicine", "Internal Medicine", "Nephrology", "Primary Care" ]

departments

[ "Renal" ]

tags

[]

version_number

1

versions

[]

related

[ { "calcId": 60, "short_title_en": "FENa", "slug": "fractional-excretion-sodium-fena" }, { "calcId": 43, "short_title_en": "Creatinine Clearance", "slug": "creatinine-clearance-cockcroft-gault-equation" }, { "calcId": 76, "short_title_en": "MDRD GFR Equation", "slug": "mdrd-gfr-equation" } ]

ismed

false

section

[ "pearlsPitfallsViewed", "nextStepsViewed", "evidenceViewed" ]

cleaned_departments

[ "urology" ]

cleaned_use

[]

pub

true