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What is a lumbar puncture?

A lumbar puncture (also known as a “spinal tap”) is done to remove a small amount of cerebrospinal fluid. This fluid surrounds the brain and spinal cord.

Why is a lumbar puncture done?
A lumbar puncture is done so that the cerebrospinal fluid can be tested. Many problems can be diagnosed by testing the cerebrospinal fluid. The fluid can be tested for bacteria, viruses, sugar or protein. The pressure of the fluid in the spinal canal may also be measured. Your  doctor or nurse can answer questions about this procedure and the tests that will be done.
How is a lumbar puncture done?

• Before the test you may have a special cream applied to the back. This cream will make the skin feel numb. It may take up to an hour for the cream to work.

• You will be put on your side. The nurse will help you drow up your knees to the chest, arching the back. Sometimes the lumbar puncture is done with the sitting up.The skin of the lower back is cleaned with an antiseptic solution. This may feel wet and cold. The doctor may inject a local anesthetic into the skin to numb the area.

• A special needle is then inserted into the spinal canal between two vertebrae. A small amount of fluid (1 to 3 teaspoons) will be taken for testing.
• The needle is removed, and a bandage placed over the site. This procedure usually takes about 10 to 15 minutes.

What follow-up care is needed after the lumbar puncture?
• You will need to lie on his or her back and rest afterward. You may hold your small child. Your child can slowly increase activity throughout the day.
• You should drink plenty of fluids unless fluids are limited as part of their treatment plan.
• If you have back pain or a headache, ask doctor or nurse what medicine should be used to relieve pain.