Creatinine Clearance (24 Hrs Urine & Serum)

Overview:

What is this test?

This laboratory test is performed on a blood and urine sample to measure the amount of creatinine that has passed from the blood into the urine. Creatinine is a waste product of muscles formed by the breakdown of creatine; an amino acid that provides energy for muscle contraction. Creatinine is filtered by the kidney and excreted into the urine.

Why is this test performed?

This test is performed:

1. To help in the diagnosis of a kidney disease
2. To help in the diagnosis of congestive heart failure
3. To monitor the progress of treatment
4. To evaluate the severity of the disease

• Sample collection: Urine samples are collected over a period of 24 hours followed by the collection of a blood sample
• The samples are sent to the laboratory to evaluate the creatinine clearance.

1. How to prepare for this test?

Overnight fasting is required before the test. Avoid consuming meat and inform your doctor about the use of all prescribed and non-prescribed medicines. Wear a short-sleeved shirt to aid the collection of sample and avoid contamination of the urine sample.

2. Is it necessary to collect urine over 24-hours?

Yes, it is necessary to collect the entire urine over 24-hours period as it gives an average creatinine levels over the entire day.

3. What should I do if I have skipped urine collection in 24 hours?

If you have skipped urine collection in between the 24-hour collection, inform your laboratory because the test may become invalid.

4. What are the risks of this test?

• Collecting blood from a vein is a very easy procedure and pose only minimum risk, including:
• Bruising
• Bleeding
• Infection
• Lightheadedness
• Collecting urine is painless, it is like urinating normally.

5. What are the symptoms of a kidney disease?

• Unexplained weight loss
• Decreased appetite
• Shortness of breath
• Swollen ankles, hands, or feet
• Urinary frequency
• Cloudy urine
• Itchy skin
• Increased thirst
• Fatigue

Normal range:

Males: 97-137 ml/min

Females: 88-128 ml/min

Interpretation of test results:

• Causes of decreased creatinine clearance:

1. Kidney failure
2. Kidney damage
3. Kidney infections
4. Kidney stones
5. Heart failure
6. Dehydration
7. Bladder obstruction.

• Causes of increased creatinine clearance:

1. Carbon monoxide poisoning
2. Pregnancy.

You should get tested:

1. If you have sign and symptoms of a kidney disease
2. If you are at an increased risk of a kidney disease
3. If your doctor suspects decreased blood flow towards the heart
4. If you have the sign and symptoms of congestive heart failure
5. To help the doctor in evaluating the need for dialysis.