Creatinine Clearance Test
600 Kshs | Home Collection Available
Synonyms
None
Purpose
The Creatinine Clearance Test evaluates kidney function by measuring how efficiently your kidneys remove creatinine from the blood and excrete it in the urine.
To perform the test, clinicians collect a timed urine sample (usually 24 hours) and a blood sample to measure creatinine concentrations in both. They then calculate the clearance rate, which serves as an estimate of the glomerular filtration rate (GFR).
This test is important because it provides a more direct measure of kidney filtration capacity than serum creatinine alone and helps detect early declines in renal function, guide dosing of renal-clearing medications, and monitor chronic kidney disease progression.
For a full diagnostic picture, the test can be done alongside Serum Creatinine, Blood Urea Nitrogen (BUN), Estimated GFR (eGFR), Urinalysis, and Electrolyte Panel. These complementary tests give a comprehensive picture of renal health and help tailor treatment plans.
Patient Preparation
The patient should avoid cephalosporin and hydrate throughout the clearance.
Samples
1ml serum or plasma and 10ml aliquot of entire urine collection, with a minimum volume of 0.7ml serum and 0.5 urine aliquot collected in a Gel-barrier, red-top or green top tube (lithium heparin). Avoid using EDTA, oxalate, or citrate plasma and plastic urine containers with or without 6N HCL.
Serum or plasma should be separated within 45 minutes of sample collection. All urine should be collected, including the final specimen at the end of 24/24-hour collection period, mixed, and the lid secured. Label the container with the patient’s details (name, date of collection time). Store the sample at room temperature.
Reference Range
Male and female <12 years: 50-90ml/min, male >12years: 97-137ml/min, female >12 years:88-128ml/min
Results Turnaround
Within 24 hours of sample receipt.
Diseases / Diagnostic indicators
The Creatinine Clearance test provides a direct estimate of glomerular filtration rate (GFR) and overall kidney function. Some possible outcomes of the test include;
Normal Clearance Rate
Indicates that your kidneys are filtering creatinine and, by extension, blood efficiently.
Reduced Clearance Rate
Suggests decreased kidney function or early chronic kidney disease. The lower the clearance, the more severe the impairment.
Elevated Clearance Rate
Uncommon but may occur in cases of increased renal blood flow (e.g., pregnancy) or measurement errors (incomplete urine collection).
Clinicians use these results alongside serum creatinine, BUN, and eGFR to confirm kidney health, adjust dosages for renal excreted medications, and monitor disease progression. For more on the Creatinine Clearance Test, read this study.