This page tells you about a test called a lumbar puncture. You can find the following information
What is a lumbar puncture?
A lumbar puncture is a test to check the fluid that circulates round the brain and spinal cord (the cerebrospinal fluid or CSF). It can check for cancer cells or for infection in the CSF.
Having a lumbar puncture
You can have a lumbar puncture as an outpatient. There is no special preparation beforehand. You may wear a gown. You usually lie on your side and bring your knees up slightly towards your chest so that your rounded back is towards the doctor. Sometimes people have the test sitting up and leaning forward.
To prevent infection your doctor will wear gloves and put some sterile covers over you. The doctor will clean your lower back and inject a local anaesthetic to numb the area. Then they push a needle very carefully into the small of your back. The needle goes into the space around the spinal cord. It takes a few seconds for a few drops of fluid to drip from the needle into a sterile pot. The doctor takes the needle out and covers the site with a dressing or plaster. Then they send the sample to the laboratory where a pathologist examines the fluid under a microscope.
A lumbar puncture can be uncomfortable but is not usually painful. You may feel some pressure when the needle first goes in. After the test you need to lie flat for an hour or so to prevent a headache. You may still get a headache up to a couple of days afterwards, so make sure you have some painkillers at home in case. You may also have mild lower back pain for a couple of days. Infection or bleeding after this test is very rare. You should contact the hospital or GP if your headache lasts longer than a week or is severe, or if you get a high temperature, are being sick, your eyes are sensitive to bright lights or you have tingling or numbness in your legs.
If you have the test as an emergency, you may get the results within a couple of hours. Generally, it can take up to a couple of weeks. If you have not heard anything after this time, ring your doctor's secretary or specialist nurse to check if the results are back.
A lumbar puncture is a test to check the fluid that circulates round the brain and spinal cord (the cerebrospinal fluid or CSF). For cancer, this test is usually done to see if there are any cancer cells in the fluid. But it is also used to look for infection.
First, your nurse may ask you to change into a gown. They will then ask you to lie on your side at the edge of the bed and curl up slightly so that your back rounds towards the doctor, who will be behind you. Or you may sit leaning forward. It is important to keep as still as you can during the test, so make sure you are reasonably comfortable before the doctor starts.
The doctor will put on gloves and drape some sterile covers over you before they start. They will then clean the area around your lower back. This all helps to stop infection from getting into your spinal fluid. The doctor will inject a little local anaesthetic to numb the area. Once the anaesthetic has worked, they will push the needle very carefully into the small of your back. The needle goes into the space around the spinal cord. Once it is in the right place, it only takes a couple of seconds for a few drops of fluid to drip out into a sterile pot. Then the doctor takes the needle out and puts a dressing or plaster on your back. The fluid is sent to the laboratory and examined under the microscope for cancer cells. The diagram below shows how you may lie and where the doctor puts the needle.
A lumbar puncture can be uncomfortable, but is not usually painful because of the local anaesthetic. You may feel some pressure and a slight soreness when the needle first goes in. Children may have some type of sedative before the test so that they are sleepy and can lie still, or a general anaesthetic.
After a lumbar puncture, you can usually go home the same day. But your doctor will probably ask you to lie flat for an hour or so after the test. This helps to prevent a headache afterwards. Drinking plenty may also help. You may still get a headache up to a couple of days after this test, so make sure you have some painkillers at home in case. The headache may last for a few days. If it doesn't get better after a week, contact your GP.
You may have mild lower back pain for a couple of days after the test. Painkillers such as paracetamol can help. There is a risk of bleeding and infection but this is very rare. You should contact your hospital if you get symptoms such as a high temperature, severe headache, are being sick, your eyes are sensitive to bright light or have tingling or numbness in your legs. Your nurse will tell you what symptoms to look out for and who to contact if you have any problems at home.
It can take time for test results to come through. How long will depend on why you are having the test. It could be a day or two but can be up to a couple of weeks. The sample of spinal fluid goes straight to the medical laboratory. There, a pathologist examines it under a microscope and does tests. What exactly is done will depend on why you are having the lumbar puncture. When all the tests are done, the pathologist dictates a report. The typed up report then goes to your specialist, who gives the results to you.
Understandably, waiting for results can make you anxious. If your doctor needs the results urgently, they will put that on the request form and so the results may be ready the same day. Try to remember to ask your doctor how long you should expect to wait for the results when you go for the test. If it is not an emergency, and you have not heard a couple of weeks after your test, ring your doctor's secretary or specialist nurse to check if they are back.
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