Lumbar puncture

You have fluid taken during a lumbar puncture to check whether leukaemia cells have spread into the fluid around the brain and spinal cord. The fluid is called cerebrospinal fluid (CSF).

Doctors or nurses remove some of the fluid to test for cancer cells. They use a needle to take a sample of the CSF from your lower back.

Diagram showing how you have a lumbar puncture

You normally have this test under local anaesthetic. This means you are awake but the area is numb. It usually doesn't take very long and is generally not very painful.

Preparing for your lumbar puncture

Check your appointment letter for how to prepare for your lumbar puncture test. You are usually able to eat and drink before your test. Take your medications as normal. 

Children and some adults may have this under a general anaesthetic (GA) Open a glossary item or with sedation. You have to stop eating and drinking for some time before the test if you're having a GA. 

What happens

Your doctor will give you information about the procedure and ask you to sign a consent form. This is a good time to ask any questions you may have.

A staff member asks you to take off your upper clothing and put on a hospital gown.

You usually lie on your side with your knees tucked up into your chest. It's important to stay as still as you can during the test, so make sure you are comfortable before it starts.

The doctor or nurse drapes some sterile covers over you. Then they clean the area with antiseptic fluid, which can feel cold.

You have an injection of anaesthetic into the area, this can sting for a few seconds. When the area is numb, the doctor or nurse puts the lumbar puncture needle in through the skin. It goes into the small of your back and into the space around the spinal cord. You might feel some pressure when the needle goes in.

Once it's in the right place, the fluid drips out into a pot. This only takes a few seconds.

Your doctor or nurse takes the needle out and puts a dressing or plaster on your back.

The whole test takes about 20 to 30 minutes. It can be uncomfortable but it's not usually painful.

After your lumbar puncture

You lie flat for an hour or so after the test.

Tell your doctor or nurse if you have a headache, so they can give you some pain killers. Lying flat and drinking plenty of fluids may relieve your headache. This may last for a couple of days so make sure you have pain killers to take home. 

You will have a dressing on the skin where they did the test. You usually remove this the next day.

You can usually go home the same day. 

Getting your results

Your scan will be looked at by a specialist doctor and you should get your results within 1 or 2 weeks. You won't get any results at the time of the scan. 

Waiting for test results can make you anxious. Ask your doctor or nurse how long it will take to get them. Contact them if you haven’t heard anything after a couple of weeks.

You might have the contact details for a specialist nurse. You can contact them for information and support if you need to. It may help to talk to a close friend or relative about how you feel. 

For support and information, you can call the Cancer Research UK nurses on freephone 0808 800 4040. The lines are open from 9am to 5pm, Monday to Friday.

Contact the doctor that arranged the test if you haven't heard anything after a couple of weeks.

Possible risks

A lumbar puncture is a very safe procedure but your nurse will tell you who to contact if you have any problems after your test.

Your doctors will make sure the benefits of having a lumbar puncture outweigh these possible risks.

Headache

If your headache doesn't get better contact your hospital team.

Pain

You might have lower back pain for a couple of days after the test. Contact your hospital team if the pain is severe.

Bleeding

You might notice a small amount of blood stained ooze on the plaster or dressing. 

Very rarely you may have bleeding for more than 15 minutes. Contact your hospital team, they can give you advice on what best to do.

Infection

This is very rare. Contact the hospital straight away if you:

  • have a high temperature
  • are being sick
  • are sensitive to bright light
  • have tingling or numbness in your legs
  • have a severe headache

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