Urea Clearance
Test code
CPT code(s)*
Clinical significance
Test resources
Details
Includes
Urea Nitrogen (BUN)
Urea Nitrogen, 24 Hour Urine
Urea Clearance (calculation)
CPT code 81050 may be added at an additional charge for volume measurement
Methodology
Spectrophotometry (SP)
Specimen requirements | |
|---|---|
| Patient preparation | None Specified |
| Preferred specimen(s) | 10 mL urine aliquot from a 24-hour urine collection, collected in a plastic urine container, no preservative and 1 mL serum |
| Alternative specimen(s) | Urine: Urine preserved with 6N HCl to maintain a pH of <4. Preserved urine may be shipped at room temperature. Urinalysis transport tube (yellow-top, blue fill line, preservative tube) • Plasma collected in: Sodium heparin (green-top) tube or lithium heparin (green-top) tube |
| Minimum volume | 2 mL urine • 0.5 mL serum or plasma |
| Collection instructions | Aliquot from a well-mixed 24-hour collection. Record total volume on both the transport container and the test requisition. |
| Transport container | Urine: Plastic urine container Serum or plasma: Transport tube |
| Transport temperature | Urine: Refrigerated (cold packs) Serum or plasma: Room temperature |
| Specimen stability | Urine Room temperature: 24 hours Refrigerated: 7 days Frozen: Indefinitely Serum and plasma Room temperature: 7 days Refrigerated: 5 days Frozen: 28 days |
| Reject criteria | Anticoagulants other than heparin |
Reference Range(s)
Urea Nitrogen (BUN)
| Male (mg/dL) | Female (mg/dL) | ||||
| <1 Month | 4-12 | 3-17 | |||
| 1-11 Months | 2-13 | 4-14 | |||
| 1-3 Years | 3-12 | 3-14 | |||
| 4-19 Years | 7-20 | 7-20 | |||
| ≥20 Years | 7-25 | 7-25 |
| Urea Nitrogen, 24 Hour Urine | 6-17 g/24 h |
| Urea Nitrogen Clearance | 41-68 mL/min |
Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.
*The CPT codes provided are based on AMA guidance and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.
This material contains content from LOINC® (http://loinc.org). The LOINC Table, LOINC Table Core are copyright © 1995-2019, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee and is available at no cost under the license at http://loinc.org/license.
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