Urea Nitrogen, 24-Hour Urine

Casandra

Casandra Test Code LC35270Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 003541CPT Code 84540

Urea Nitrogen, 24-Hour Urine

Also known as: BUN, Nitrogen Balance Study, Urine Urea Nitrogen

Clinical Use

Order Test

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

Not provided.

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.

Test Details

Methodology

Automated Analyzer (Clinical Chemistry)

Biomarkers

LOINC Codes

Order Codes

3095-7 - UUN Ur-mCnc
3096-5 - UUN 24h Ur-mRate

Result Codes

3095-7 - UUN Ur-mCnc
3096-5 - UUN 24h Ur-mRate

Result Turnaround Time

1 day

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.