Skip Ribbon Commands
Skip to main content
Sign In

22941 Urea Nitrogen

Urea Nitrogen
Test Code: BUN
Synonyms/Keywords
BUN, Blood Urea Nitrogen​, i-Stat BUN
Useful For
Urea nitrogen measurements are used in the diagnosis and treatment of certain renal and metabolic diseases.​
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
No​ ​

Plasma​/Serum

 

Lithium-heparin Plasma Separator (PST), Serum Separator Tube (SST)​ Lithium or Sodium-heparin Green Top (GTT), Red Top Tube (RTT) 1 mL​ 0.5 mL​ 0.5 mL whole blood​
​i-Stat only = Whole Blood ​Lithium-heparin Green Top Tube (GTT) ​1 mL ​200uL
Collection Processing Instructions
Samples collected in a RTT or GTT must be removed from cells within one hour for storage or transport. Samples collected in gel barrier tubes must be removed from the primary tube prior to transporting to Marshfield. Do not send the primary collection tube.
 
Stat orders will be run locally on the i-Stat.  Non-stat orders will be sent to Marshfield for analysis. 
i-Stat:  Sample must be tested within 10 minutes of collection.
Specimen Stability Information
Specimen Type Temperature Time
Plasma/Serum​ Ambient​ 5 days​
Refrigerate​ 7 days​
Frozen​ 3 months​
i-Stat Whole Blood​ ​Ambient ​10 minutes
Rejection Criteria
Specimens in ammonium heparinate or oxalate
i-Stat testing:  clotted samples​
​i-Stat testing: anticoagulants other than lithium heparin
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Bloomer ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Cadott ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Chetek ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
​​
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Chippewa Falls ​​Monday through Friday ​Less than 2 hours​ ​Biochromatic Rate Technique/Siemens Dimension
​Colby/Abbotsford ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Cornell ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Cumberland ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Diagnostic Treatment Center ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Eagle River ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
​​
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Eau Claire ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Flambeau Hospital ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Hayward ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Ladysmith Medical Center ​​Monday through Sunday ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Lake Hallie Monday through Friday

1 day (sent to Marshfield)

* stat order on i-Stat run locally = Less than 2 hours

Hexokinase-UV/NAD Endpoint Assay/ Beckman AU
Amperometrical-Enzymatic/i-Stat​
​Lakeview Medical Center ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
Marshfield​ Monday through Sunday​ Less than 2 hours​ Urease GLDH Rate Assay/Beckman AU
​Mercer ​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Merrill ​Monday through Saturday ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Minocqua ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
Mosinee​ ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
​​Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Neillsville​Monday through Friday​Less than 2 hoursBiochromatic Rate Technique/Siemens Dimension​
​Oakwood ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
​​Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Phillips ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
Rhinelander​ ​Monday throgh Friday 1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat​
Stettin​ ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Stevens Point ​​Monday through Friday ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
Wausau​ ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
Wisconsin Rapids​ ​​Monday through Friday ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Wittenberg ​​Monday through Friday 1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
Reference Range Information
Performing Location Reference Range
All Performing Sites

0-1 year: 1-14 mg/dL

2 - 17 years: 5-20 mg/dL

>=18 years: 6-24 mg/dL​

See Critical Value Policy for list of current critical values.​​ ​
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
84520
Synonyms/Keywords
BUN, Blood Urea Nitrogen​, i-Stat BUN
Ordering Applications
Ordering Application Description
​Centricity

​a. BUN (Blood Urea Nitrogen)

b. Urea Nitrogen-Blood (BUN)

c. BUN

​Cerner ​Blood Urea Nitrogen
​COM ​Urea Nitrogen - Blood (BUN)
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Fasting Required Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)
No​ ​

Plasma​/Serum

 

Lithium-heparin Plasma Separator (PST), Serum Separator Tube (SST)​ Lithium or Sodium-heparin Green Top (GTT), Red Top Tube (RTT) 1 mL​ 0.5 mL​ 0.5 mL whole blood​
​i-Stat only = Whole Blood ​Lithium-heparin Green Top Tube (GTT) ​1 mL ​200uL
Collection Processing
Samples collected in a RTT or GTT must be removed from cells within one hour for storage or transport. Samples collected in gel barrier tubes must be removed from the primary tube prior to transporting to Marshfield. Do not send the primary collection tube.
 
Stat orders will be run locally on the i-Stat.  Non-stat orders will be sent to Marshfield for analysis. 
i-Stat:  Sample must be tested within 10 minutes of collection.
Specimen Stability Information
Specimen Type Temperature Time
Plasma/Serum​ Ambient​ 5 days​
Refrigerate​ 7 days​
Frozen​ 3 months​
i-Stat Whole Blood​ ​Ambient ​10 minutes
Rejection Criteria
Specimens in ammonium heparinate or oxalate
i-Stat testing:  clotted samples​
​i-Stat testing: anticoagulants other than lithium heparin
Useful For
Urea nitrogen measurements are used in the diagnosis and treatment of certain renal and metabolic diseases.​
Reference Range Information
Performing Location Reference Range
All Performing Sites

0-1 year: 1-14 mg/dL

2 - 17 years: 5-20 mg/dL

>=18 years: 6-24 mg/dL​

See Critical Value Policy for list of current critical values.​​ ​
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Bloomer ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Cadott ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Chetek ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
​​
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Chippewa Falls ​​Monday through Friday ​Less than 2 hours​ ​Biochromatic Rate Technique/Siemens Dimension
​Colby/Abbotsford ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Cornell ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Cumberland ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Diagnostic Treatment Center ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Eagle River ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
​​
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Eau Claire ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Flambeau Hospital ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Hayward ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Ladysmith Medical Center ​​Monday through Sunday ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Lake Hallie Monday through Friday

1 day (sent to Marshfield)

* stat order on i-Stat run locally = Less than 2 hours

Hexokinase-UV/NAD Endpoint Assay/ Beckman AU
Amperometrical-Enzymatic/i-Stat​
​Lakeview Medical Center ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
Marshfield​ Monday through Sunday​ Less than 2 hours​ Urease GLDH Rate Assay/Beckman AU
​Mercer ​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Merrill ​Monday through Saturday ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Minocqua ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
Mosinee​ ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
​​Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Neillsville​Monday through Friday​Less than 2 hoursBiochromatic Rate Technique/Siemens Dimension​
​Oakwood ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
​​Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Phillips ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
Rhinelander​ ​Monday throgh Friday 1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat​
Stettin​ ​​Monday through Friday
1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
​Stevens Point ​​Monday through Friday ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
Wausau​ ​Monday through Sunday​ ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
Wisconsin Rapids​ ​​Monday through Friday ​Less than 2 hours​ ​​Biochromatic Rate Technique/Siemens Dimension
​Wittenberg ​​Monday through Friday 1 day (sent to Marshfield)
* stat order on i-Stat run locally = Less than 2 hours
Urease GLDH Rate Assay/Beckman AU
​Ion-Selective Electrode/i-Stat
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
84520
For most current information refer to the Marshfield Laboratory online reference manual.