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Urea Nitrogen (BUN)

Alternate Name: BUN

  | Blood urea nitrogen

SAL Code:

305

CPT:

84520

Loinc:

3094-0

Turn Around Time:

1 Day

Setup:

Daily

Units:

mg/dL

Department:

Chemistry

Performing Laboratory:

Sherman Abrams Laboratory

Specimen Requirements:

Primary Tube:

SST

Primary Substance:

Serum

Temperature

Period

Stable Ambient:

7 Days

Stable Fridge:

7 Days

Stable Frozen:

14 Days

Rejection Criteria:

Improper labeling

Clinical Info:

Urea is the principle waste product of protein catabolism. BUN is most commonly measured in the diagnosis and treatment of certain renal and metabolic diseases. Increased BUN concentration may result from increased production of urea due to (1) diet or excessive destruction of cellular proteins as occurs in massive infection and fevers, (2) reduced renal perfusion resulting from dehydration or heart failure, (3) nearly all types of kidney disease, and (4) mechanical obstruction to urine excretion such as is caused by stones, tumors, infection, or stricture. Decreased urea levels are less frequent and can occur in patients with advanced liver disease or in patients that are overhydrated.
Low BUN can also be seen in routine pregnancy and in patients with decreased protein intake and in patients receiving IV fluids.
Several drugs can cause both an increase and a decrease in BUN levels.

Additional Information:

Although creatinine is generally considered a more specific test to evaluate renal function, very often BUN is used with creatinine in the diagnosis and treatment of certain renal and metabolic diseases.

Sample Collection:

Collect patient samples using standard phlebotomy techniques. Click here for additional collection instructions.

Specimen Handling Instructions:

Maintain at room temperatrure.

Test Information:

Components:

Brooklyn Navy Yard
Building 292, Suite 416
63 Flushing Avenue
Brooklyn, NY 11205

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