Lumbar Puncture

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Lumbar puncture (or LP, also known as a spinal tap) is a diagnostic and at times therapeutic procedure that is performed in order to collect a sample of cerebrospinal fluid (CSF) for biochemical, microbiological, and cytological analysis, or very rarely as a treatment ("therapeutic lumbar puncture") to relieve increased intracranial pressure.

Need to Know

Nice to Know
  • You will be asked to sign a consent form before the procedure is performed
  • Tell your radiologist about any allergies, especially to local or general anesthetics and contrast materials (“x-ray dye”)
  • If you are taking a blood thinner or aspirin product, the physician will instruct you when to stop taking these medications
  • If you are diabetic, the physician will give you insulin and/or anti-diabetic medication dosing instructions
  • Inform your radiologist if you are pregnant
  • You will be awake during the procedure and can go home afterward
  • You will be given a gown to wear during your treatment
  • You will probably be asked to use the bathroom before the procedure


How Does It Work?

Using image-guidance from fluoroscopy (x-rays that show motion inside your body in real- time) or CT scans, your doctor or mid-level provider will place a spinal needle between the lumbar vertebrae and pushed the needle in the subarachnoid space. Once the spinal needle is in place one can start to collect cerebrospinal fluid. The opening pressure of the cerebrospinal fluid may be taken during this collection by using a simple column manometer. The procedure is ended by withdrawing the needle while placing pressure on the puncture site.

What Happens — Before, During, and After?

When you arrive for your procedure a clinical staff member will greet you and let the team know you’ve arrived. You will be brought into an exam room and asked to change into a gown. Your doctor or mid-level provider will greet you, explain the procedure and answer any questions you may have.

You will likely lie on your abdomen on the exam table for this procedure. In some cases patients receive an IV line but this most-likely will not be necessary. Your doctor or mid-level provider will clean the area with an antiseptic solution and cover it with a surgical drape. Your doctor or mid-level provider will then give you a shot of local anesthesia to numb the area. You will feel a small pinch as the anesthesia is administered.

Once the area is numb, your doctor or mid-level provider will use either fluoroscopic imaging - which uses X-rays to guide the spinal needle.

Your doctor or mid-level provider will slowly guide the spinal needle into the subarachnoid space in your spine. Once the spinal needle is in place, your doctor or mid-level provider will begin collecting spinal fluid. You may feel some discomfort as the needle enters your spine. This should only last a short moment and will most likely dissipate as soon as the needle is removed.

In most cases this procedure takes only a few minutes. Once the procedure is complete, the spinal needle will be removed and you will likely have a small bandage over the puncture. You may need to stay in the doctor’s office for a short while (perhaps an hour) until you feel ready to go home.

You may feel some difficulty walking or standing up/sitting down immediately after the procedure. This should subside within a few hours. Your doctor will likely tell you to rest for the remainder of the day but you may resume your normal activities the following day.

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How Should I Prepare?

There are things you can do to make your experience more comfortable, and many of these will depend on your individual preferences. You might like to keep a list of questions or – as you’re doing now- educate yourself about the procedure.

Another important part of your preparation will be guided by your doctor:

  • Your doctor may ask you to stop taking aspirin, non-steroidal anti-inflammatory drugs (NSAIDS), or blood thinners (such as Coumadin, Warfarin, Plavix, Fragmin) for a time before the procedure.

Some of your preparation will need to be timed to the procedure:

  • The day before the procedure (or the Friday before, if you’re scheduled for a Monday procedure), a clinical staff member from the Interventional Radiology Department will call you. The clinical staff member will give you any additional instructions, and will ask if you have any questions.
  • Take your medications as instructed
  • When you arrive, make sure the clinical staff member and radiologist know about any allergies you may have, especially allergies to local anesthetics (such as lidocaine), general anesthetics, or x-ray dye (contrast media). If there’s any chance you might be pregnant, tell your radiologist.
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What Should I Bring?

  • Wear comfortable, loose-fitting clothes
  • Wear comfortable shoes
  • Avoid bringing jewelry or valuables
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What Are the Benefits and Risks?

The benefits of Lumbar Puncture could be:

  • A lumbar puncture could, depending upon the exact situation for which it is performed, provide lifesaving information

Risks you should be aware of include:

  • When spinal fluid is removed during a lumbar puncture, the risks include headache, brain herniation, bleeding, and infection
  • Each of these complications is uncommon with the exception of headache, which can appear from hours to up to a day after LP
  • Headaches occur less frequently when the patient remains lying flat 1-3 hours after the procedure
  • There is a slight risk of nerve damage
  • If fluoroscopy is used, there are risks associated with exposure to X-ray. You should discuss these with your physician

Keep in mind that this information is general. Your radiologist is the best source of information about how these risks and benefits may apply to you

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