What is a caudal epidural?
A caudal epidural injection in the lower back can be used to treat a number of different painful conditions. The injection is most commonly used to treat pain in the leg, called sciatica. The injections are given into your back, at the lowest point of your spine. The injection goes into an area known as the epidural space. This is the space that surrounds the spinal cord. The nerves that carry pain sensations pass through this space.
A caudal epidural injection bathes the nerves and intervertebral discs in local anaesthetic and, if used, steroid solution. Only a small amount of steroid is needed. This will not cause any of the side effects sometimes associated with taking steroid tablets. They are not the same kind of steroids that athletes may take.
This steroid injection relieves pain by reducing the inflammation. Pain from inflamed nerves that is felt in the leg (sciatica) can be treated. By bathing inflamed discs, caused by injury or general wear and tear (degeneration), some lower back pain may be reduced. The medication is injected just outside the covering of the spinal cord, which is called the dura; hence the name epidural.
Sometimes your doctor may inject a dye into the spinal canal. This would be to perform a test called an epidurogram. The dye is x-ray opaque, meaning it shows up on x-rays. The test may show areas of scarring that may be causing some of your pain. Scarring may be present, particularly if you have had previous surgery.
What has gone wrong?
Your intervertebral discs in your spine have suffered degeneration, which is general wear and tear, or damage from an injury. When the disc is inflamed, the nearby nerves can become irritated. These nerves supply sensation to the leg and hence the brain is fooled into believing that the leg is injured. This is not the case; although you may feel leg pain the problem is in the spine.
The aim of the procedure is to reduce the inflammation of the disc. This in turn reduces the leg pain and some of the lower back pain.
Your pain should be reduced and you should be able to move around more easily. The physiotherapist will show you exercises to help prevent the problem happening again. If successful, this treatment can avoid the need for surgery.
Are there any alternatives?
By the time that you have the caudal epidural injection you should have already tried other more simple treatments. These include rest, painkilling and anti-inflammatory tablets, and physiotherapy with exercise.
What if you do nothing?
If you do nothing there are several things that may happen:
With time and rest the inflammation and pain may settle on its own
The pain and difficulty in moving around may remain the same
The pain may get worse
The disc may become further damaged and injure the nerves that control movement. You may then develop weakness and difficulty in moving your legs. Some of this may become permanent
In rare, but severe cases, you may lose control of your bladder and bowels. The nerves that control these are in the same area of the spine and can be damaged by an inflamed disc
Who should have it done?
The following groups of patients should have the procedure done:
Who should not have it done?
Each patient must make the final decision as to whether to proceed or not. If you are unhappy about the procedure for any reason you should not continue.
There are specific medical situations when a caudal epidural should not be done and they are as follows:
When a patient is on medication that prevents blood from clotting, such as warfarin. This would lead to more bleeding than normal. It may be possible to stop the medication a few days before the procedure. This will need to be discussed with your doctor
When a patient is suffering from an illness that prevents blood from clotting, such as haemophilia. This would also lead to more bleeding than normal
When there is infection of the skin over the site where the needle needs to be put in
When a patient has a bloodstream infection
When a patient has noticed a recent worsening of their symptoms, especially weakness and loss of bladder or bowel control
Author: Dr Sean White FRCA. Consultant in pain and anaesthesia
© Dumas Ltd 2006