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Epic Test Code LAB21108 Urea Nitrogen/Creatinine Ratio

Important Note

This test CANNOT be ordered as a single test.  Urea Nitrogen and Creatinine Serum tests must be included with all requests for a Urea Nitroge/Creatinine Ratio (BCR).

This test is only available on Inpatient orders when a BUN and Creatinine are ordered together on the same specimen.

Performing Location(s)

BMC,FOX,FTT,CRH,LFH,OCH,FXCC,HRK

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 followed by transfer of the serum (red or gold top) or plasma (green top) to a labeled plastic aliquot.

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
>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

Reference Values

Population Units Reference Range
All Populations (none) 10-20

 

Days of Analysis

All

Available STAT

Yes

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.

Methodology

Calculated from Urea Nitrogen and Creatinine.

CPT Code

A Urea Nitrogen (84520) and a Creatinine (82565) will be performed and billed.  There is no charge for the calculation.

Last Updated

21-Jun-22 BHD