Creatinine Clearance With Body Surface Area Normalization
Also known as: Clearance, Creatinine
Use
The Creatinine Clearance with Body Surface Area Normalization test is used to evaluate kidney function by measuring how effectively creatinine, a waste product of muscle metabolism, is cleared from the blood by the kidneys. This test helps in assessing glomerular filtration rate (GFR), providing critical information for diagnosing and managing conditions affecting kidney health, such as chronic kidney disease (CKD). By including body surface area normalization, the test accounts for variations in patients' sizes, offering a more standardized assessment of kidney function.
Special Instructions
The test request form must include details of the date and time when the urine collection started and ended, as well as the patient's height and weight. It is essential to state the 24-hour urine volume on the request form. Proper documentation ensures accurate normalization of test results for patient-specific factors.
Limitations
Creatinine clearance estimation may be influenced by factors other than glomerular function, such as muscle mass and diet. This test may not fully reflect kidney function in patients with muscle wasting or those on specific diets. Medications like cephalosporins can interfere with creatinine measurements, potentially leading to inaccurate results. Proper patient preparation and adherence to guidelines are crucial.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 34555-3
- 2160-0
- 2161-8
- 2162-6
- 2164-2
- 3141-9
- 3137-7
- 8277-6
- 98979-8
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Red-top tube, gel-barrier tube, green-top (heparin) tube, or lavender-top (EDTA) tube
Collection Instructions
Separate serum from cells within 45 minutes of collection. Submit both urine and serum simultaneously. It is preferable to collect the serum at the time the urine collection is completed or when the serum is brought to the draw station.
Patient Preparation
Patient should avoid taking cephalosporins. Have patient drink water before the clearance is begun, and continue good hydration throughout the clearance. If possible, drugs should be stopped beforehand.
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 |