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HelpTest Code BUN Blood Urea Nitrogen
Specimen and Container/Tube
Specimen Type: Plasma
Preferred Specimen: Li-Heparin Mint Green Top
Other Acceptable specimens: Serum/Gold Top, Serum/Red Top
Volume
Preferred Volume: 0.5 mL
Minimum Volume: 0.2 mL
Specimen Stability
|
Storage Temperature |
Stability |
|
Room temperature |
7 days |
|
Refrigerated |
7 days |
|
Frozen |
12 months |
Collection Instructions
Collect specimen per standard laboratory collection procedures.
Specimen Handling and Transport Instructions
UCMC Onsite Instructions:
Collect specimen per standard collection procedure and send to laboratory immediately.
UCMC Offsite and UC MedLab Outreach Instructions:
- Samples should be centrifuged within 2 hours of collection.
- Centrifuge specimens at >2500 x g for 10 minutes at room temperature.
- Aliquot sample into plastic transport tube containing a minimum of 0.2 mL of specimen.
- Samples must be sent room temperature at 15-25oC.
Rejection Criteria
- Common specimen rejected situations include: incorrect specimen type, insufficient volume, missing or incomplete specimen identifiers, incorrect specimen transport, or specimens outside stability limits.
- Specimens that are clotted or grossly hemolyzed.
- Specimens that were transported unspun/whole blood and draw time is greater than 6 hours.
Reference Values
|
Test |
Age |
Sex |
Reference Range |
|
Blood Urea Nitrogen |
All |
All |
7-20 mg/dL |
Critical Values
Not applicable
Turnaround Time
Turnaround times are relative to the time the specimen is received in the test laboratory.
STAT Turnaround Time: 1 hour
Routine Turnaround Time: 4 hours
Testing Schedule: 24/7
Clinical Indications
The determination of urea is the most widely used test for the evaluation of kidney function. The test is frequently used in conjunction with the determination of creatinine for the differential diagnosis of prerenal hyperuremia (cardiac decompensation, water depletion, increased protein catabolism), renal hyperuremia (glomerulonephritis, chronic nephritis, polycystic kidney, nephrosclerosis, tubular necrosis) and postrenal hyperuremia (obstructions of the urinary tract).
Test Components
Blood Urea Nitrogen
Methodology
Spectrophotometric, Kinetic (Roche Diagnostics)
CPT Codes
84540
LOINC Codes
3094-0
Synonyms/Keyword Search
Urea, BUN
Additional Information
Results should always be assessed in conjunction with patient's medical history, clinical examination and other findings.
Also included in Basic Metabolic Panel KPNL, Comprehensive Metabolic Panel CPNL, ER Panel I STKG, Renal Function Panel RPNL, CMP for chronic lymphocytic leukemia (CPNL FOR CLL PATIENTS ONLY) SSTCP, BMP for chronic lymphocytic leukemia (KPNL FOR CLL PATIENTS ONLY) SSTKP
Last Review Date
8/19/2024