Urea Nitrogen, Blood

Message

Performing Lab: Central Lab, Hudson, Lakeview, Regions, Sartell, Westfields

Test Code

0108

Alias/See Also

Sunquest: BUN

CPT Codes
84520

Preferred Specimen

0.1 mL Lithium Heparin Plasma (light green-top) tube

Minimum Volume

52 uL

Other Acceptable Specimens

Serum (gold-top, red-top, red/gray-top), Lithium Heparin (light green-top) on ICE

Transport Temperature

Refrigerated

Specimen Stability

Room temperature (7 days), Refrigerated (7 days), Frozen (1 year)

Methodology
Urease

Setup Schedule

Hospital: Daily
Clinics: Monday - Friday

Report Available

Same day.

Reference Range

7 - 26 mg/dL
ALL SITES Critical: >= 100 mg/dL

Clinical Significance

The major pathway of nitrogen excretion is in the form of urea that is synthesized in the liver, released into the blood, and cleared by the kidneys. A high serum urea nitrogen occurs in glomerulonephritis, shock, urinary tract obstruction, pyelonephritis, and other causes of acute and chronic renal failure. Severe congestive heart failure, hyperalimentation, diabetic ketoacidosis, dehydration, and bleeding from the gastrointestinal tract elevate urea nitrogen. Low urea nitrogen often occurs in normal pregnancy, with decreased protein intake, in acute liver failure, and with intravenous fluid administration.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.