Lumbar Puncture

Lumbar Puncture

Doctors will usually arrange a lumbar puncture to find out if your child has an infection of the lining or the fluid around their brain. A doctor inserts a needle in the lower back to get a sample of the fluid that moves around the brain and spine.

Share

Key points to remember about a lumbar puncture

  • a lumbar puncture is usually done to find out if your child has an infection of the lining or the fluid around their brain
  • a doctor inserts a needle in the lower back to get a sample of the fluid that moves around the brain and spine

What is a lumbar puncture?

A lumbar puncture is also called a spinal tap or LP. A doctor inserts a needle in the lower back to get a sample of cerebrospinal fluid (CSF) that moves around the brain and spine. The needle does not go near the spinal cord.

Why would my child need a lumbar puncture?

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.

Check information on meningococcal disease

Occasionally your child may need a lumbar puncture for another reason. If this is the case, your doctor will explain the reason.

What happens during a lumbar puncture?

The test may be a little bit awkward as your child needs to be still the whole time and may feel some discomfort.

Local anaesthetic patch

Your child may have a local anaesthetic patch placed on the skin by a doctor or nurse. This numbs the area where they will put the needle. It takes about 30 to 60 minutes for the patch to work.

Medicine to relax

If your child is very scared or anxious, the doctor may give them some medicine that will help them to relax.

Lying still

It is very important that during this test your child does not move. A nurse will hold them gently but firmly to make sure they stay still.

Your child will lie curled up on their side with their knees tucked up under their chin.

Cleaning the skin

A doctor will clean the skin on the lower part of your child's back.

Local anaesthetic injection

Your doctor may also use local anaesthetic that they inject into the skin over your child's lower back. The local anaesthetic may sting and it takes a couple of minutes to start working.

Inserting the lumbar needle

The doctor will carefully insert the lumbar needle.

Removing drops of spinal fluid

The drops of spinal fluid are collected quickly into small tubes, and then the needle is removed.

Covering with a plaster

The doctor or nurse will put a small plaster over the area.

Can a lumbar puncture cause any problems?

Sometimes the lumbar puncture is not successful. Either it is not possible to get any fluid, or blood is collected instead of fluid.

The doctor will make sure that it is safe for your child to have the test and there are very few side effects from a lumbar puncture.

After the test, a small number of children may complain of feeling sore where the needle went in, and some m. Some children may have a headache for up to a couple of days.

Complications such as nerve damage and infection are very rare. A lumbar puncture is done below where the spinal cord ends, so it is not possible to injure the spinal cord.

What happens after a lumbar puncture?

If the lumbar puncture is done to look for infection, the results will usually be available within a few hours. There may be a dressing or a plaster covering the spot where the needle went in. You may notice a little bit of swelling where the needle went in, but this should disappear over a couple of days.

What can I do to help during the lumbar puncture?

If your child asks about what is happening, be honest, reassure them and explain the test in simple terms.

Be comforting and reassuring even though you are concerned. Your child will be more relaxed if you appear relaxed.

You may be able to comfort and reassure your child while the lumbar puncture is being done, But, if you are not able to stay with your child, then a staff member will stay and comfort them.

The staff are there to help and you are welcome to ask them if you would like more information.

There are a number of ways you can help your child if they are having healthcare treatment.

Check some tips about helping your child having treatment

What can I do to help after the lumbar puncture?

If your child complains of a headache or a sore back, it may be helpful to give your child some mild pain relief such as paracetamol and allow your child to rest. When giving paracetamol, you must follow the dosage instructions on the bottle. It is dangerous to give more than the recommended dose.

If your child has a headache, give them plenty to drink and encourage them to lie down. If the headache becomes severe or does not go away, take your child to see their doctor.

Acknowledgements

The Paediatric Society of New Zealand acknowledge the co-operation of The Children's Hospital at Westmead, Sydney Children's Hospital at Randwick, and Kaleidoscope - Hunter Children's Health Network in making this content available to patients and families.

Tags
Tests

This page last reviewed 01 December 2021.

Call Healthline on 0800 611 116 any time of the day or night for free health advice when you need it