Sodium Fractional Excretion, URN

Lab Name

Na Fractional Excretion, URN

Lab Code

UNAFE

Epic Name

Sodium Fractional Excretion, Urine

Synonyms

FENA

Components

Code	Name
CREPU	Creatinine/Unit, Urine
NAPU	Sodium, URN
NAFE	Sodium Fractional Excretion

Reference Range: See individual components
Ref. Range Notes: Less than 1%:

In patients with markedly reduced GFR, a fractional excretion of sodium of less than 1% is consistent with prerenal disease.

1%-2%:

Indeterminate. Patients with prerenal disease on diuretics may have a fractional excretion of sodium greater than 1%. Some patients with acute tubular necrosis have a fractional excretion of sodium less than 2%.

Greater than 2%:

Consistent with acute tubular necrosis.

Specimen Type: Urine
Collection: Random Urine (no preservatives) in yellow top urine collection tube (UA no additive) PLUS blood sodium and creatinine collected within 24 hours of the urine

Unacceptable: Any timed urine collection
Handling Instructions: Urine: No preservative required, refrigeration preferred.
Quantity: Requested: 8 mL urine + 0.5 mL serum/plasma
Minimum: 1 mL urine + 0.2 mL serum/plasma

Lab Department

Chemistry, Automated Panels(CHA)

Frequency

Daily

Available STAT?

Yes

Performing Location(s)

HMC	Chemistry, Automated 206-520-4600 325 9th Ave, Rm # GWH-47, Seattle, WA 98104-2420
UW-NW	Main Lab 206-668-1344 UW Medical Center – Northwest 1550 N 115th Street, A200 Seattle, WA 98133
UW-MT	Chemistry, Automated 206-520-4600 Clinical Lab, Room NW220, University of Washington Medical Center, 1959 NE Pacific street, Seattle, WA 98195

General Information