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HelpTest Code URCLHW Urea Clearance
Synonyms/Keywords
Urea Clear (Corr with Ht/Wt)
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 | Urine AND Plasma/Serum | Urine Container Lithium-heparin Plasma Separator (PST), Serum Separator Tube (SST) | Lithium or Sodium-heparin Green Top (GTT), Red Top Tube (RTT) | 10 mL Urine AND 1 mL Plasma/Serum | 1 mL Urine AND 0.3 mL Plasma/Serum |
Collection/Processing Instructions
Aliquot from timed urine (24 hour or 48 hour collection interval is preferred) collected without a preservative. The total volume collected must be measured, recorded, and included with the test request.
The blood specimen ideally should be drawn during the urine collection time interval, however blood specimens drawn no longer than 24 hours prior to the start of the collection or within 24 hours after the collection ends are usually acceptable.
Patient's height (within 1 inch) and weight (within 10 lbs) should be submitted with the request to allow for result correction to standardized 1.73 sq. meter body surface area.
Clearance is calculated using the usual method (U/P x V) and makes no correction for tubular reabsorption at slower urine flow rates, i.e. the "maximum urea clearance" is assumed.
The blood specimen must be ordered separately as either a BUN or as part of a Basic Metabolic Profile.
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine - No Preservative | Ambient | 2 hours |
| Refrigerated | 4 days | |
| Urine - With Preservative | Refrigerate | 7 days |
| Plasma/Serum | Ambient | 5 days |
| Refrigerated | 7 days | |
| Frozen | 3 months |
Rejection Criteria
Plasma or serum specimens collected in ammonium heparinate or oxalate
Test Components
Blood Urea, Urine Urea and Creatinine
Reference Range Information
| Performing Location | Reference Range |
|---|---|
| All Performing Sites | 64-99 mL/min |
Marshfield Labs Performing Department
Marshfield Labs Chemistry
Performing Information
| Performing Location | Day(s) Test Performed | Analytical Time | Methodology/Instrumentation |
|---|---|---|---|
| Marshfield | Monday through Sunday | 6-8 hours | Urease GLDH & Modified Jaffe/Beckman AU |
CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 84545 |
Outreach CPT Codes
| CPT | Modifier (if needed) |
Quantity | Description | Comments |
|---|---|---|---|---|
| 84545 |
Ordering Applications
| Ordering Application | Description |
|---|---|
| Cerner | Urea Clear (Corr with Ht/Wt) |