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Epic Test Code LAB140 Urea Nitrogen: Serum (BUN)

Performing Location(s)

BMC,CRH,LFH,HRK,OCH,FTT,FOC,FCC

Specimen Type

Serum or Plasma

Preferred Container

Gold or Red top tube

Alternate Container

Green top tube

Blood Tube Draw Volume

Min 50% draw volume  

Minimum Volume to Submit for Testing

0.5 mL Serum or Plasma

  • Multiple test can be performed from this volume. For question please contact the lab at 547-3975.  

Storage Requirements

Sample tubes should be centrifuged within 2 hours of collection 

Gold tops are stable in original tubes for 7 days DO NOT ALIQUOT

Aliquot Red tops after centrifuging 

See Causes of Rejection for temperature requirements.

Transportation Needs

Deliver specimen to laboratory within 1 hour of collection if unspun. If not possible see "storage Requirements". 

Causes for Rejection

Mislabeled or unlabeled specimen
Less than 50% draw for Vacutainer tubes
 >4 days refrigerated
> 24 hours room temperature
> 2 months Frozen
Hemolysis > 500 mg/dL HgB
Lipemia > 500 mg/dL Trig
Bilirubin > 20 mg/dL Bili

Limitations

This method reacts quantitatively within ammonium ions

Reference Values

Population Units Reference Range
</= 1 month mg/dL 3-10
> 1 month mg/dL 7-25

 

Days of Analysis

All

Available STAT

Yes

Includes

Quantitative analysis for Urea Nitrogen

 

BCR is calculated on Inpatient orders only when both BUN and CRTN are ordered.

Methodology

Beckman AU/Dx Series

Additional Information

Additional Information:

Uremia is best evaluated with Creatinine as well as by urea nitrogen in both prerenal and postrenal azotemia. For instance, BUN is apt to be increased somewhat more than creatinine in chronic progressive renal disease.

About three quarters of the renal parenchyma must be damaged or destroyed before azotemia develops.
 

For Kinetic Modeling or Recirculation Studies on Dialysis patients see Urea Nitrogen, Dialysis

CPT Code

84520

Last Updated

26-OCT-24 MS