Creatinine measurement, 24 hour urine

This test measures creatinine (a product of protein breakdown) in urine and blood. It is used to determine glomerular filtration rate, which helps to measure how well the kidney functions. This test may be used in suspected cases of gout, impaired kidney functionand kidney disease in diabetic patients.

Laboratory tests may be done for many reasons. Tests are performed for routine health screenings or if a disease or toxicity is suspected. Lab tests may be used to determine if a medical condition is improving or worsening. Lab tests may also be used to measure the success or failure of a medication or treatment plan. Lab tests may be ordered for professional or legal reasons. You may need this test if you have:

• Diabetic kidney disease
• Impaired kidney function

Venous blood:

Before having blood collected, tell the person drawing your blood if you are allergic to latex. Tell the healthcare worker if you have a medical condition or are using a medication or supplement that causes excessive bleeding. Also tell the healthcare worker if you have felt nauseated, lightheaded, or have fainted while having blood drawn in the past.

24 hour urine collection:

During a 24-hour urine collection, follow your usual diet and drink fluids as you ordinarily would, unless healthcare workers give you other instructions. Avoid drinking alcohol before and during the urine collection.

Tell the person doing the test if you are pregnant.

Do not exercise before this test.

A sample of blood and urine may be collected for this test.

Venous blood:

When a blood sample from a vein is needed, a vein in your arm is usually selected. A tourniquet (large rubber strap) may be secured above the vein. The skin over the vein will be cleaned, and a needle will be inserted. You will be asked to hold very still while your blood is collected. Blood will be collected into one or more tubes, and the tourniquet will be removed. When enough blood has been collected, the healthcare worker will take the needle out.

24 hour urine collection:

For a 24-hour urine collection, all of the urine that you pass over a 24-hour time period must be collected. If you are in the hospital, a healthcare worker will collect your urine. You will receive a special container to collect the sample in if you are doing the collection at home. The following are directions for collecting a 24-hour urine sample while at home:

• In the morning scheduled to begin the urine collection, urinate in the toilet and flush away the first urine you pass. Write down the date and time. That is the start date and time for the collection.

• Collect all urine you pass, day and night, for 24 hours. Use the container given to you to collect the urine. Avoid using other containers. The urine sample must include the last urine that you pass 24 hours after starting the collection. Do not allow toilet paper, stool, or anything else to be added to the urine sample.

• Write down the date and time that the last sample is collected.

• The urine sample may need to be kept cool during the 24-hour collection period. If so, keep the closed container in a pan on ice. Do not put ice in the container with the urine.

How will the test feel?

The amount of discomfort you feel will depend on many factors, including your sensitivity to pain. Communicate how you are feeling with the person doing the test. Inform the person doing the test if you feel that you cannot continue with the test.

Venous blood:

During a blood draw, you may feel mild discomfort at the location where the blood sample is being collected.

24 hour urine collection:

This test usually causes no discomfort.

Venous blood:

After a blood sample is collected from your vein, a bandage, cotton ball, or gauze may be placed on the area where the needle was inserted. You may be asked to apply pressure to the area. Avoid strenuous exercise immediately after your blood draw. Contact your healthcare worker if you feel pain or see redness, swelling, or discharge from the puncture site.

24 hour urine collection:

When 24-hour urine collection is complete, close the container and seal the lid tightly. Return the sample in the urine container to the facility or healthcare worker as instructed. If you had the sample in an ice bath, return the sample within two hours after removing the container from the ice bath.

You have the right to help plan your care. To help with this plan, you must learn about your health condition and how it may be treated. You can then discuss treatment options with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.