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Order Code LAB4878 Sodium, Fractional Excretion, Plasma or Serum and Urine

Additional Codes

Test Name in EPIC

EPIC Test Code           

Mnemonic

RV FENA

LAB4878

FENA

 

Useful For

To determine if hypovolemia or decreased effective circulating plasma volume is a contributor to acute kidney failure

Specimen Requirements

Serum or plasma and urine are required. The blood and urine specimens should be collected within 4 hours of each other. 

  

Urine

10 mL from a random urine collection in a urine specimen cup. Send specimen refrigerated.

Note: Label specimen appropriately (urine).

 

Submit only 1 of the following specimens:

 

Plasma

Draw blood in a green-top (lithium heparin gel) tube. Spin down and send 1 mL of plasma refrigerated.

Note:  Label specimen appropriately (plasma)

 

Serum

Draw blood in a plain, red-top tube or a serum gel tube. Spin down and send 1 mL of serum refrigerated.

Note:  Label specimen appropriately (serum)

Specimen Stability

Specimen Type Temperature Stability     
Plasma/Serum/Urine Refrigerated 7 days         

Reference Values

Adults:

  • Less than 1% suggests prerenal azotemia
  • Greater than 3% suggests acute tubular necrosis

Day(s) Test Set Up

Monday through Sunday

Performing Laboratory

Ridgeview Medical Center Laboratory

Methodology

Potentiometric

Test Classification and CPT Coding

82565 - Creatinine, serum

82570 - Creatinine, urine

84295 - Sodium, serum

84300-Sodium, urine