A spinal tap or LP (lumbar puncture) may be done to remove a small amount of spinal fluid for examination, to give medicine into the spinal canal or to measure the pressure in the spinal canal.
How the Test Is Done
Your child may have sedation or anesthesia for the procedure if he or she is not able or is too young to cooperate.
Treatment to relieve pain, such as EMLA® cream (applied to the skin about 1 hour before the test), may be used to numb your child’s skin. Just before the test, a small amount of numbing medicine is injected into the skin. This may sting at first.
The doctor or nurse practitioner will have your child lie down on his or her left side and "curl up in a ball" on a padded table in the treatment or exam room (Picture 1). It is important for him to bend as much as possible.
The doctor or nurse will feel your child's back and choose a space between the bones of the lower part of the spine to insert the needle. A sterilizing solution will be used to wash this spot on the skin. This may feel cold. After the skin is washed, some towels will be put around the clean spot on the skin where the test will be done. It is very important that your child holds very still during the test. A nurse will hold your child to remind him not to move. If the doctor cannot feel the bones, the LP may need to be done with image guidance, such as ultrasound or fluoroscopy.
After the skin is numb, a needle will be inserted into the spinal canal. Your child will still feel pressure as the needle is put in, but it should not hurt. The doctor or nurse may ask your child to straighten out. A small amount of spinal fluid that looks like water will drip into sample tubes.
The needle will be removed and a Band-Aid® will be placed over the spot where the test was done. The fluid in the tubes will be sent to the lab for testing.
After the Test
Your child may be asked to lie flat for a little while to reduce the chance of getting a headache. Reading to him and quiet play will help him stay flat in bed. The spinal tap site should be checked regularly for bleeding or wetness. The site should be kept clean and dry. The Band-Aid® should stay in place for 24 hours and then be removed. Your child should not take a tub bath or shower while the Band-Aid® is in place. The doctor will explain the laboratory report and discuss the plan of treatment with you.
Spinal Tap (PDF)
HH-III-21 1/79, Revised 5/14 Copyright 1979, Nationwide Children’s Hospital