Creatinine Clearance

The Creatinine Clearance test contains 1 test with 8 biomarkers.

Brief Description: The Creatinine Clearance test is a diagnostic procedure that evaluates how effectively the kidneys are filtering small molecules like creatinine out of the blood and excreting them into the urine. Creatinine is a waste product derived from the breakdown of creatine, a compound that plays a vital role in generating energy for muscles. Since the kidneys are responsible for eliminating creatinine from the body, the rate at which this occurs can offer essential insights into kidney function.

Also Known As: CRCL Test, CCT Test

Collection Method: Blood Draw and Urine Collection

Specimen Type: Serum and Urine

Test Preparation: No preparation required

When is a Creatinine Clearance test ordered?

When a doctor wants to assess a patient's kidneys' capacity for filtration, they may order a creatinine clearance test. When a person, for instance, exhibits elevated blood creatinine concentrations on a typical chemical panel or protein in the urine on a typical urinalysis, it may be ordered as a follow-up test. When there is a suspicion of a kidney ailment due to certain signs and symptoms, it could be ordered.

These are some warning signs and symptoms of renal issues:

• Swelling or puffiness, especially in the face, wrists, abdomen, thighs, or ankles or around the eyes
• Foamy, bloody, or coffee-colored urine
• a reduction in the urine's volume
• problems urinating, such as a burning sensation or an unusual discharge, or a change in frequency, particularly at night
• discomfort in the middle of the back, below the ribs, and next to the kidneys
• elevated blood pressure
• pee with blood or protein in it

When it is known that a person has a renal problem or reduced blood supply to the kidneys as a result of a condition like congestive heart failure, the creatinine clearance may also be ordered on a regular basis.

What does a Creatinine Clearance test check for?

Muscles release creatinine as a waste product after breaking down a substance called creatine. The kidneys filter creatinine from the blood and release it into the urine. A creatinine clearance test assesses the levels of creatinine in both a blood sample and a urine sample from a 24-hour urine collection. The amount of creatinine that has been eliminated from the blood and excreted in the urine is determined using the findings. This calculation enables a broad assessment of the volume of blood that the kidneys filter over the course of a 24-hour period.

Creatinine production in the body is largely consistent for a person and is influenced by muscle mass. The kidneys' capacity to filter the blood as well as the rate at which blood is transported to the kidneys determine how much creatinine is excreted from the blood.

The glomerular filtration rate is the measure of how much blood the kidneys filter each minute. Less creatinine will be excreted in the urine and released into the blood in the presence of renal disease or damage, or if blood circulation is impeded. As a result, the GFR will fall.

GFR is challenging to directly measure. As a result, it is advised to compute estimated GFR by testing the blood's creatinine level and plugging the data into an algorithm. the formula that accounts for a number of variables, including the test subject's age, gender, and race.

Calculating creatinine clearance is an additional, less popular method of estimating GFR. There are various ways to calculate creatinine clearance. The measurement of the creatinine concentration in a blood sample taken just before or after the urine collection, the creatinine concentration in a 24-hour urine sample, and the 24-hour urine volume are all included. Some estimates also incorporate a correction factor that takes into consideration a person's body surface area because the amount of creatinine generated is dependent on muscle mass.

Lab tests often ordered with a Creatinine Clearance test:

When a Creatinine Clearance test is ordered, it's often part of a broader evaluation of kidney health. Here are some tests commonly ordered alongside it:

1. Serum Creatinine:

   • Purpose: To measure the level of creatinine in the blood.
   • Why Is It Ordered: To compare with urine creatinine levels and help calculate the creatinine clearance rate. Serum creatinine is a key marker used to estimate overall kidney function.

2. Blood Urea Nitrogen (BUN):

   • Purpose: To measure the amount of urea nitrogen in the blood.
   • Why Is It Ordered: To provide additional information about kidney function. Elevated BUN levels can indicate impaired kidney function, dehydration, or increased protein breakdown.

3. Complete Blood Count (CBC):

   • Purpose: To evaluate overall blood health.
   • Why Is It Ordered: To check for anemia or other blood cell abnormalities, which can occur with chronic kidney disease (CKD).

4. Electrolyte Panel:

   • Purpose: To measure key electrolytes in the blood.
   • Why Is It Ordered: To check for electrolyte imbalances, which can be a consequence of kidney dysfunction.

5. Urine Analysis (UA):

   • Purpose: To analyze various components of the urine.
   • Why Is It Ordered: To check for abnormal substances in the urine, such as protein, blood, or signs of infection, which can indicate kidney damage or disease.

6. Albumin-to-Creatinine Ratio (ACR) (in a random urine sample):

   • Purpose: To assess the presence of albumin in the urine.
   • Why Is It Ordered: To detect early stages of kidney damage. Persistent albuminuria is a sign of kidney disease, especially important in individuals with diabetes or hypertension.

These tests, when ordered alongside a Creatinine Clearance test, provide a comprehensive evaluation of kidney function. They are crucial for diagnosing and monitoring kidney disease, understanding its severity, and guiding treatment. The specific combination of tests will depend on the individual’s symptoms, clinical presentation, and medical history.

Conditions where a Creatinine Clearance test is recommended:

Various diseases and conditions can impact kidney function, leading to the need for a Creatinine Clearance test. Some of these include:

• Chronic Kidney Disease (CKD): Progressive loss of kidney function over time.
• Acute Kidney Injury (AKI): A sudden episode of kidney failure or kidney damage.
• Glomerulonephritis: Inflammation of the tiny filters in the kidneys (glomeruli).
• Polycystic Kidney Disease (PKD): A genetic disorder characterized by the growth of numerous cysts in the kidneys.

How does my health care provider use a Creatinine Clearance test?

Kidney dysfunction may be identified and diagnosed with a creatinine clearance test. It could be applied as a follow-up to abnormal blood creatinine test and estimated glomerular filtration rate results.

When congestive heart failure is present, as might happen, a creatinine clearance may also be utilized to identify the existence of decreased blood flow to the kidneys.

The creatinine clearance test may be prescribed in cases of known chronic renal disease or congestive heart failure in order to track the development of the condition and gauge its severity. Moreover, it can be utilized to assist decide whether and when kidney dialysis could be required.

What do my Creatinine Clearance test results mean?

The presence of renal disease or other diseases that can impair kidney function may be indicated by a reduced creatinine clearance. They may consist of:

• For instance, infections or autoimmune illnesses can cause kidney blood vessels to enlarge or become damaged.
• infection of the kidneys with bacteria
• death of kidney cells brought on by chemicals or medications, for instance, in the tiny tubes of the kidneys
• Urinary tract obstruction can be brought on by prostate disease, kidney stones, or other conditions.
• reduced kidney blood flow brought on by shock, dehydration, congestive heart failure, atherosclerosis, or diabetes-related problems.

Although this test isn't commonly used to track these disorders, elevated creatinine clearance rates can occasionally be noticed during pregnancy, exercise, and with meals heavy in meat.

Most Common Questions About the Creatinine Clearance test:

Purpose and Indications for the Creatinine Clearance Test

What is the primary purpose of the Creatinine Clearance test?

The Creatinine Clearance test is primarily used to evaluate the function of the kidneys and determine their filtering capability. It provides an estimate of the glomerular filtration rate (GFR), which reflects the amount of blood filtered by the kidneys per minute.

Why would someone need to take the Creatinine Clearance test?

A healthcare provider might advise a Creatinine Clearance test to assess kidney function, particularly if they suspect kidney disease or wish to monitor the progression of an existing kidney condition. The test can also be used to adjust drug dosages, as many medications are excreted by the kidneys and might require dose modifications based on kidney function.

Interpreting the Results

What do the results of the Creatinine Clearance test indicate?

The results show the amount of creatinine cleared from the blood by the kidneys in a given timeframe, typically 24 hours. The results are often given in milliliters per minute (mL/min). A decreased creatinine clearance rate indicates impaired kidney function. The degree of reduction can give an indication of the severity of kidney disease.

How do creatinine clearance rates correlate with kidney function?

A decreased creatinine clearance rate is a sign of decreased kidney function. The lower the rate, the less efficiently the kidneys are filtering blood. It's worth noting that as age increases, it's normal for the clearance rate to decrease somewhat. Other factors like muscle mass can also influence creatinine production and subsequently the clearance rate.

Follow-up and Treatment

What should be the next step after receiving the results of my Creatinine Clearance test?

If your Creatinine Clearance test indicates impaired kidney function, it's crucial to consult with a nephrologist or primary care physician. They can guide you on further diagnostic tests, potential causes, monitoring strategies, and suitable treatments.

Is there a way to improve or stabilize my creatinine clearance rate?

Treatment to improve or stabilize creatinine clearance largely depends on the underlying cause of the kidney dysfunction. Managing conditions like hypertension or diabetes, which can affect kidney function, is essential. Specific medications might be prescribed to control symptoms and slow the progression of kidney disease. Lifestyle changes, such as a balanced diet, limited protein intake, and reduced salt consumption, might also be recommended.

Disease Progression and Complications

Can a persistently low creatinine clearance rate indicate chronic kidney disease?

Yes, a consistently low creatinine clearance rate is a significant indicator of chronic kidney disease (CKD). CKD has various stages, and creatinine clearance can help in determining the stage and the severity of kidney damage.

Are there other tests or evaluations I should consider if I have a low creatinine clearance?

Yes, if you have a reduced creatinine clearance, other evaluations like serum creatinine, blood urea nitrogen (BUN), urine albumin, and imaging tests of the kidneys might be recommended. These tests provide a comprehensive assessment of kidney health and function.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.