What is a lumbar puncture?
A lumbar puncture is a procedure used to get a sample of
spinal fluid for lab tests. It may also be done to inject
medicine or dye. The term lumbar refers to the lower back
between the pelvis and the ribs. This test is also called a
spinal tap.
When is it used?
This procedure is used to:
- Check for infection or other signs of disease that may be
affecting your brain and spinal cord (such as
meningitis).
- Inject drugs to treat leukemia or diseases of the nervous
system.
- Inject dye for x-rays used to diagnose diseases affecting
the spine.
- Inject an anesthetic to numb your lower body for surgery.
How do I prepare for a lumbar puncture?
No preparation is needed unless the health care provider
gives you special instructions.
What happens during the procedure?
This procedure can be done in your health care provider's
office or in a hospital. It takes less than 20 minutes.
First you may be given a sedative. The sedative will relax
you and reduce anxiety. It may cause you to fall asleep.
Usually, you will lie on one side with your knees bent and
pulled up with your chin touching your chest. This position
allows the bones or vertebrae in the spine to separate so
that your health care provider can insert a needle between
the vertebrae of your spine and into the spinal canal. Your
provider may use the needle to get a sample of spinal fluid.
You may be given a local anesthetic to numb the skin before
the needle is inserted.
What happens after the procedure?
Sterile tape is applied to your skin where the needle was
inserted. You may have a headache after the procedure.
Lying down for a while after the procedure may help avoid a
headache.
Ask your health care provider how to take care of yourself
and when you should come back for a checkup.
What are the benefits of this procedure?
A lumbar puncture can help your health care provider make a
more accurate diagnosis. When it is used to give an
anesthetic, you will not feel any pain during surgery
although you will be able to stay awake.
What are the risks associated with this procedure?
- A local anesthetic may not numb the area quite enough and
you may feel some minor discomfort. Also, in rare cases,
you may have an allergic reaction to the drug used in
this type of anesthesia.
- You may have a headache for several days that gets worse
when you sit up or stand up.
- Rarely, infection may develop in the skin where the
needle was inserted.
Ask your health care provider how these risks apply to you.
When should I call my health care provider?
Call your health care provider right away if:
- You notice any unusual drainage, including bloody
discharge, where the needle was inserted.
- You develop a fever.
- Pain, including headache pain, or other symptoms worsen.
Call your health care provider during office hours if:
- You have questions about the procedure or its result.
- You want to make another appointment.
This content is reviewed periodically and is subject to
change as new health information becomes available. The
information is intended to inform and educate and is not a
replacement for medical evaluation, advice, diagnosis or
treatment by a healthcare professional.
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