Urea Nitrogen, 24-Hour Urine
Also known as: BUN, Nitrogen Balance Study, Urine Urea Nitrogen
Use
Renal function test; coarse nitrogen-wasting test on patients on hyperalimentation; indicate nitrogen balance in hyperalimentation; rule out tap of urinary bladder in amniocentesis, paracentesis
Special Instructions
Record the total 24-hour urine volume on the request form to ensure accurate results.
Limitations
The result of the Urea Nitrogen, 24-Hour Urine test can be affected by improper collection, labeling, and handling of the specimen. Accurate recording of the 24-hour urine volume is crucial. In some cases, additional time should be allowed for confirmatory or reflex tests. Testing schedules may vary.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 3095-7
- 3096-5
- 3095-7
- 3096-5
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
10 mL aliquot of entire collection
Minimum Volume
1 mL aliquot
Container
Plastic urine container, no preservative
Collection Instructions
Refrigerate the specimen as it is collected. Instruct the patient to void at 8 AM and discard the specimen. Then collect all urine including the final specimen voided at the end of the 24-hour collection period (ie, 8 AM the next morning). Screw the lid on securely. Container must be labeled with patient's full name, date and time collection started, and date and time collection finished.
Storage Instructions
Refrigerate the specimen during collection.
Causes for Rejection
Improper labeling
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |