Urea Nitrogen

Label Mnemonic:	BUN
Epic code:	LAB140
Downtime form:	Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Chemistry
6240 RCP
356-3527

Specimen(s):

Plasma

Collection Medium:

Plasma Separator Tube 4.5 mL

Alternate Collection Media:

Call laboratory for additional acceptable specimen collection containers.

Minimum:

3 mL whole blood in light green top tube or ONE Microtainer^® for pediatric patients.

Testing Schedule:

24 hrs/day, 7 days a week, including holidays.

Turn Around Time:

1 hour (upon receipt in laboratory)

Reference Range:

10-20 mg/dL

Comments:

Refer to BD Microtainer^® Tubes product sheet for detailed sample collection instructions.

This test is also performed in the Iowa River Landing (IRL) clinical laboratory (for specimens drawn at that site).

Test Limitations:

Criterion: Recovery within plus or minus 10% of initial values.

Plasma
Icterus: No significant interference up to an I index of 60 
(approximate conjugated and unconjugated bilirubin concentration: 60 
mg/dL).

Hemolysis: No significant interference up to an H index of 1000 
(approximate hemoglobin concentration: 1000 mg/dL)

Lipemia (Intralipid): No significant interference up to an L index of 
1000. There is poor correlation between turbidity and triglycerides 
concentration.

Great care must be taken to prevent ammonia contamination of the 
specimens to be analyzed for urea/urea nitrogen.

Methodology:

Enzymatic

CPT Code:

84520

See also:
Urea Nitrogen-Other, Body Fluid