Creatinine with Estimated Glomerular Filtration Rate (eGFR), Serum
Use
This test is useful for diagnosing and monitoring acute and chronic kidney diseases, adjusting dosages of renally excreted medications, and monitoring kidney transplant recipients. It is also used for estimating the glomerular filtration rate (eGFR) for individuals with chronic kidney disease (CKD) and those with risk factors such as diabetes, hypertension, cardiovascular disease, and a family history of kidney disease. The eGFR provides a more practical means to closely follow changes in GFR over time compared to direct measurement methods such as iothalamate clearance.
Special Instructions
Patient's age and sex are required for this test. If not ordering electronically, complete, print, and send either the Kidney Transplant Test Request or the Renal Diagnostics Test Request form with the specimen.
Limitations
Creatinine is synthesized from creatine and creatine phosphate and is primarily removed from plasma by glomerular filtration. Creatinine clearance can overestimate true GFR by 10% to 20%. Serum or blood creatinine levels generally increase only after significant kidney function impairment. Drugs can influence creatinine levels independent of GFR. High levels of muscle mass can mislead interpretations of serum creatinine levels.
FDA ApprovedNew York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 45066-8
- 2160-0
- 98979-8
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
0.5 mL
Container
Serum gel or Red top tube; Plastic vial
Collection Instructions
Serum gel tubes should be centrifuged within 2 hours of collection. Red-top tubes should be centrifuged and the serum aliquoted into a plastic vial within 2 hours of collection.
Storage Instructions
Serum should be refrigerated for up to 7 days, ambient up to 24 hours, and frozen for 90 days.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |
| Refrigerated | 7 days |
| Frozen | 90 days |