UREA NITROGEN, BLOOD

Mnemonic

BUN

Synonym

Urea Nitrogen (UN) in Serum/Plasma - Blood Urea Estimate - Blood Urea Nitrogen (BUN)

Specimen Collection Requirements

Collect

Serum or Plasma, one 5.0 mL gold (SST), 7.0 mL red or 3.0 mL mint green (lithium heparin, PST) top tube

Handling

Allow serum to clot completely at room temperature (minimum: 30 minutes). Preferably, separate serum or plasma from cells before transport.

Preferred Volume

0.5 mL

Minimum Volume

0.3 mL

Transport

Refrigerated (2-8°C)

Rejection Criteria

Grossly hemolyzed specimens

Stability

Lithium heparin specimens (PST) are stable up to 7 days refrigerated on the primary spun gel tube AFTER SEPARATION FROM CELLS: Ambient (18-25°C): 24 hours; Refrigerated (2-8°C): 7 days; Frozen (at or below -20°C): 3 months

Testing Information

Performed

7 days/week

Method

Enzymatic

Referral Lab

Samaritan Health Services Laboratories

Reference Values

Reference Values

ADULT: 8-21 mg/dL
Age adjusted ranges.
Diet and age dependent.
Note: Except for dialysis patients

Critical Values

105 mg/dL

CPT Codes

84520

Last Updated: Thursday, January 5, 2017 03:42:33 AM