Lumbar puncture

Introduction

A lumbar puncture is also known as a spinal tap. It is a test doctors use by inserting a needle in the lower back to get a sample of the cerebrospinal fluid (CSF) which moves around the brain and spine. The needle does not go near the spinal cord. 

A lumbar puncture is usually done to find out if your child has an infection of the lining or the fluid around their brain. This type of infection is called meningitis. Sometimes lumbar punctures are done for other reasons that your doctor will explain. 

Your child’s treatment team will give you information about preparing for the lumbar puncture like:

• what time to arrive
• what to bring
• what to wear
• when to stop eating and drinking (if needed).

if your child is very scared or anxious the doctor may give them some medicine that will help them to relax. The doctor or nurse will talk to you about very rare complications like nerve trauma and infection. A lumbar puncture is done below where the spinal cord ends, so it is not possible to injure the spinal cord.  

The doctor or nurse may put a local anaesthetic patch on the skin first to numb the area where they will put the needle. It takes about 30 minutes for the patch to work. 

It is very important that your child stays still during the lumbar puncture, even if they feel uncomfortable. This is to make sure the needle goes where it needs to. It is difficult to stay still, so a nurse can help gently hold your child if needed.

In the lumbar puncture:

1. your child will lie on their side, curled up with their knees tucked under their chin
2. the doctor will clean the skin on your child’s lower back
3. the doctor will carefully insert a needle into the specific spot on your child’s lower back
4. drops of CSF that come out of the needle will be collected quickly into small tubes
5. the needle is removed, and a dressing or bandage is put over the spot.

If the lumbar puncture is done to look for infection, the results will usually be available within a few hours.

Your child may have a bit of swelling and soreness where the needle went into their back. This should go down over the next few days. You may notice a little bit of swelling where the needle went in, but this should disappear over the next couple of days. 

Some children may get a dull, throbbing headache after lumbar puncture. This is called a spinal headache; it happens when your child starts to move around. You can help your child manage a spinal headache by getting them to rest, lie down, move slowly and drink fluids.

Supporting your child during a lumbar puncture

Procedures can be scary for children. This is normal. You can support your child through the lumbar puncture by being there to reassure them and answering any questions they have in simple, honest language. If you don’t know the answer to a question, you can encourage your child to ask the doctor or nurse. Doing this can help your child feel confident about their own healthcare.

If you can stay with your child during the lumbar puncture, you can help them by trying some distraction techniques. This can include:

• listening to music
• singing together
• watching a show or movie
• giving them a favourite toy.

Speak to your hospitals Child Life Therapy team for more information about supporting your child with distraction techniques.

Sometimes a parent or carer is unable to stay for the procedure. If this happens, a nurse or doctor will stay with your child to provide support.

if your child has a spinal headache or sore back, you can give them some mild pain relief like paracetamol. Follow the instructions on the packet closely.

If their headache does not go away, or gets worse, call your local doctor as soon as possible or go to the nearest emergency department.