Creatinine Clearance
Use
The Creatinine Clearance test is primarily used for assessing renal function. It estimates the glomerular filtration rate (GFR), evaluates renal function in individuals with low muscle mass, and monitors the progression of renal disease. This test is also crucial for adjusting dosages of medications that are primarily excreted via the kidneys, helping ensure safe and effective medication management.
Special Instructions
The test request form must specify the date and time collection started and finished, and must state the 24-hour urine volume. It is important to maintain good hydration, and it is preferable to collect the serum using a red-top or gel-barrier tube, within 24 hours of the start or completion of urine collection.
Limitations
Exercise may lead to elevated creatinine clearance values, and the GFR is increased during pregnancy. Various substances, such as ascorbic acid, ketone bodies, and some cephalosporins, can interfere with creatinine determinations. Certain medications may reduce creatinine excretion and certain sample types, like icteric or hemolyzed samples, may also interfere. Creatinine clearance tends to overestimate GFR in progressive renal failure and may be slightly higher in males compared to females.
Methodology
Other
Biomarkers
LOINC Codes
- 34555-3
- 2160-0
- 2161-8
- 2162-6
- 2164-2
- 98979-8
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.7 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
Separate serum from cells within 45 minutes of collection. It is preferable to collect the serum when the urine collection is completed or when the serum is brought to the draw station.
Storage Instructions
Room temperature
Causes for Rejection
No blood creatinine drawn; improper labeling
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 14 days |