Creatinine Clearance, Urine
Also known as: CRTCL
Use
The Creatinine Clearance test is a measure of kidney function by evaluating how well creatinine is removed from the blood by the kidneys. Determining the creatinine clearance rate can help diagnose kidney problems, as a decreased clearance rate indicates that the kidneys are not functioning properly, which could be a result of conditions such as chronic kidney disease or acute kidney injury. This test is commonly used to monitor patients with kidney issues and to adjust medication dosages accordingly.
Special Instructions
Specimens must include a 24-hour urine collection, ensuring refrigeration during the entire collection period. Serum or plasma must also be collected within specified time frames relative to the urine collection to ensure accurate results. Proper recording of the total volume and collection time interval on both the transport tube and test request form is essential for processing this test.
Limitations
The accuracy of the Creatinine Clearance test can be affected by incomplete urine collection or incorrect timing of blood collection relative to urine collection. Random urine collections are unacceptable, as accurate timing is crucial for valid test results. Other factors such as diet, hydration status, and body mass can influence creatinine levels and clearance calculations, potentially leading to misleading results if not accounted for in clinical evaluation. Additionally, the test may not accurately reflect kidney function in very young, elderly, or severely ill patients without additional diagnostic context.
FDA ApprovedNew York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 35674-1
- 2164-2
- 2160-0
- 19153-6
- 30211-7
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
Not provided
Minimum Volume
0.5 mL
Container
ARUP standard transport tubes
Collection Instructions
Collect 24-hour urine, ensuring it is refrigerated during the entire collection period.
Patient Preparation
Record total volume and collection time interval on transport tube and test request form.
Storage Instructions
Refrigerated.
Causes for Rejection
Random urine collections.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 1 week |
| Refrigerated | 1 week |
| Frozen | 3 months |