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Lumbar Puncture In Children

What is a lumbar puncture?

  • Your child's spine ("backbone") is made of vertebrae (VER-te-bray), the spinal cord, and cerebrospinal (ser-ee-broh-SPEYE-nal) fluid. The vertebrae are small bones that are stacked on one another to make the spine. The vertebrae stretch from your child's neck to his tailbone. The spinal canal is a space that passes through the center of the vertebrae. The spinal cord is inside the spinal canal and is surrounded by cerebrospinal fluid. Cerebrospinal fluid (CSF) bathes, cushions, and protects the brain and spinal cord. The spinal cord carries messages between your child's brain and his body.
  • A lumbar puncture test is also called an LP or a spinal tap. During an LP, a needle is inserted into your child's lower spine. A small amount of CSF fluid is then taken from the spinal canal. The CSF fluid may be sent to a lab for testing. Sometimes the CSF is taken to decrease pressure caused by certain medical problems, such as hydrocephalus. Pressure within the spinal canal can also be measured during an LP.

Why does my child need a lumbar puncture?

Your child may need an LP to check for one or more of the following:

  • Infection, such as meningitis (men-in-JEYE-tis), or inflammation (swelling) of the brain.
  • Bleeding in the brain, such as from a head injury.
  • Increased pressure that may be causing certain kinds of headaches.
  • A tumor (lump or mass) in the area of the spine or brain.
  • An LP may also be done as part of another test, such as a test that needs dye put into the CSF.
  • Some medicines can be given into the spine during an LP. Examples include anesthesia (an-es-THEE-zah) medicine, antibiotics (an-ti-bi-AH-tiks), and cancer-treating medicine (chemotherapy).

What happens during a lumbar puncture?

The actual LP usually takes about 20 to 30 minutes, but it may take longer. Your child will need to hold still for the test, and lay flat or nearly flat after the test. Your child may need other tests besides the LP. These tests may include blood tests, x-rays, or a CT ("cat") scan.

  • Informed consent: The risks and benefits of your child's LP should be explained to you in words that you know. You should be told what tests, treatments, or procedures may be needed to learn about and treat your child's health condition. You may be asked to sign a consent form. A consent form is a legal piece of paper that tells you exactly what will be done. Before giving your consent, make sure that all of your questions have been answered.
  • Before the LP:
    • Your child may eat and drink before the lumbar puncture, unless his caregiver says not to.
    • Continue giving your child his usual medicines unless caregivers tell you not to.
    • Tell caregivers if your child is allergic to iodine, medical cleaning solutions, lidocaine or any dental or numbing medicine.
    • Older children may be asked to put on a hospital gown. Put the gown on your child so that it opens in the back.
    • Older children should go to the bathroom before the LP so that they are not uncomfortable during the test.
    • Caregivers may take your child's vital signs before, during, and after the LP. This may include checking your child's temperature, blood pressure, heart rate, and breathing. Caregivers may listen to your child's heart and lungs by using a stethoscope (STETH-oh-skohp). Your child's vital signs may be taken so that caregivers can see how he is doing.
  • During the LP:
    • Your child will likely cry during the LP. This is a normal response to being around new people, and being held in one position. Hearing your child cry may be upsetting to you. Tell caregivers if you feel you may become ill or too upset to be in the same room during the LP.
    • It is important that your child holds very still during the LP so that the needle is not moved. Caregivers may need to use their hands or use restraints to hold your child still during the test. This is for your child's safety. If your child cannot hold still, he may need medicine to make him drowsy.
    • Your child's lower back will be washed with soap to clean the skin of germs. In the area where the LP will be done, your child may be given one or more shots of medicine. Cream may also be put on his skin. These medicines are given to numb (make your child lose feeling in) the area, so that he will feel less pain.
    • Caregivers will place your child in a curled-up position that rounds his back as much as possible. This helps to widen the space between the vertebrae so that the LP can be done. Your child's caregiver will carefully put a needle into a space between the vertebrae in the lower back. Your child's caregiver may need to insert the needle more than once.
    • Your child's caregiver may take readings of CSF pressure. Then, a sample of CSF may be taken. The sample may be sent to a lab for tests. A small bandage is put on your child's back after the needle is taken out.

What happens after a lumbar puncture?

  • Caregivers will check the LP site to make sure it is not bleeding too much, leaking fluid, or swelling. If your child is older, he may be asked to wiggle his toes.
  • Your child will need to lie flat or nearly flat for 30 minutes to several hours after the LP. If your child is sent home after the LP, have him lie flat or recline as much as possible on the way home. For 24 hours after the LP, have him rest as much as possible. This helps to decrease the chance of a "spinal headache". Have your child avoid hard activity (such as sports) for 48 hours after the LP.

Care for a spinal headache:

A spinal headache can happen during the first few hours to several days after the LP. The discomfort of a spinal headache can range from mild to severe (very bad). The headache may get worse when your child sits or stands. He may have neck or back pain as well. Things that may decrease the pain of a spinal headache include the following.

  • If your child gets a headache, have him lie down until the headache is better. Tell your child's caregiver if his headache is very bad and it does not get better after lying down for a while.
  • Over-the-counter medicines, such as acetaminophen (a-seet-a-MIN-oh-fen), may decrease your child's pain. Ask your caregiver which over-the-counter pain reliever is right for your child. Always follow the directions on the bottle. Never give aspirin to your child without first asking your child's caregiver. Giving aspirin to your child when he is ill may cause a very serious illness called Reye's syndrome. This could cause brain and liver damage. Read medicine labels to see if your child's medicine has aspirin in it.
  • Offer your child plenty of liquids to drink during the first 12 to 24 hours following the LP. This may help decrease the chance of a spinal headache. Good liquids to drink include water and milk. Children over the age of six months can drink juices as well. For some older children, caregivers may suggest allowing your child to drink caffeine. This may help to decrease the pain of a spinal headache. Things that have caffeine include some sodas, some tea, and some energy drinks. Ask your child's caregiver before giving your child caffeine.

What is a blood patch?

A blood patch may be used to help a spinal headache that is very bad or does not go away. This is also called an epidural (ep-i-DU-ral) blood patch. A blood patch may be done in the days or weeks following an LP. To place a blood patch, caregivers first draw blood from your child. This blood is injected with a needle into your child's back over the LP site. Your child will need to lay flat for about an hour after this is done. Your child may need IV fluids also.


There is a risk of an allergic reaction if a numbing medicine is used during the LP. Other problems are rare, such as bleeding, infection, or injury to a disk in the spine. There is also a small risk of leakage of the spinal fluid. There is a very small chance that the brain or spinal cord could be injured. The risk of problems is increased if your child moves during the LP test. If your child does not have an LP test, caregivers may not be able to find or treat his illness. Call your caregiver if you are worried or have questions about your child's medicine or care.

Care Agreement

You have the right to help plan your child's care. To help with this plan, you must learn about your child's health condition and how it may be treated. You can then discuss treatment options with your child's caregivers. Work with them to decide what care may be used to treat your child.