Diagnostic Tests
What is a lumbar puncture?
A lumbar puncture (LP or "spinal tap") is the insertion of a needle in between the bones, called vertebrae, that make up the lower portion of the spine (lumbar region) and into the fluid filled space called the spinal canal. The purpose of this procedure is to withdraw some of the fluid that surrounds the spinal cord (called cerebral spinal fluid or CSF) for testing, or administer a medication that can be injected into the spinal canal.
What you should know about this procedure
- You will be assisted into one of two positions:
- recumbent – lying on side with legs pulled up to abdomen and chin tucked to chest. (see diagram)
- sitting – seated on side of bed, leaning forward with arms and head resting on the overbed table.
- It is very important to maintain the position and remain very still during the procedure to avoid moving the needle.
- Please tell your physician if you have an allergy to betadine or xylocaine.
- Your skin will be cleansed with a solution (usually betadine).
- The physician will explain the procedure and get your consent if he/she has not already done so.
- A small amount of local anesthetic (usually Xylocaine) is injected into the area to reduce discomfort caused by the needle. With this anesthetic you may still experience some initial discomfort but you should mainly feel pressure from the needle. Please let your doctor know if you are uncomfortable. You may bring a CD or cassette to listen to during the procedure. CD and cassette players with tapes can be loaned from the resource room in the Dana lobby
- When the procedure is completed, a band-aid is applied over the area. The doctor will let you know whether you will need to lie flat for a specific period of time.
- After the procedure, mild to moderate headaches are common. Please inform your doctor if any of the following occurs: difficulty urinating, pain, swelling, drainage or bleeding at the L.P. site, or any headaches or fevers.
- If you receive intravenous medication before the procedure to help you relax, you should not operate heavy machinery, drive a car, drink alcohol or make any important decisions for 12 to 24 hours after the procedure. Your physician will let you know when you may resume your regular activities.
