With an epidural injection, drugs are administered directly into the epidural space, a combination of corticosteroids and local anesthetic.
The corticosteroid works by reducing the inflammation of the nerve, which together with the action of the local anesthetic reduces pain, primarily radicular pain in the legs (sciatica), depending on the place where the injection is given. Epidural injection is effective because a smaller amount of medicine is given exactly at the place where the inflammation and the cause of the pain are.
When is an epidural steroid injection recommended?
It is recommended in those cases where we want to relieve radicular pain (pain in the legs or arms caused by a lesion of the nerve root), in order to reduce discomfort and facilitate physical therapy. Radicular pain is most often caused by nerve inflammation due to a herniated disc. Corticosteroid by itself does not cure a herniated disc, but by reducing inflammation, it also reduces pain and allows the body to heal the herniated disc on its own. The effect of an epidural injection lasts from several weeks to several months, which is often enough to overcome the acute phase of inflammation and to resolve the herniated disc without surgery.
There are two most common reasons for using an epidural steroid injection:
1. Herniated disc resulting in pain in the leg (so-called "sciatica)" or pain in the arm if it is a herniated disc on the cervical spine
The disc tissue that comes close to the nerve in the case of a herniation brings with it chemical compounds that lead to inflammation with consequent pain. The vast majority of all disc herniations can be treated without surgery, it is only necessary to overcome the acute inflammatory phase, which hurts the most. Epidural injection aims to reduce inflammation and pain and thus keep the patient mobile and able to perform physical therapy.
The earlier the injection is applied, the greater the effectiveness; if the symptoms last less than 3 months, the pain decreases in 90% of patients.
When the complaints last from 3 to 6 months, the efficiency is about 70%, and if the complaints last longer than a year, the efficiency of the procedure is about 50%.
2. Lumbar stenosis (a disease of elderly people in which, due to degenerative changes, the spinal canal is narrowed through which the nerves that go to the legs pass)
The symptoms of this disease are low back pain, pain in the legs and the inability to walk for a long time without rest.
The mechanism of action of epidural steroid injection in this disease is somewhat different than in disc herniation, but it is also effective in 50-70% of patients. It is used to reduce discomfort in patients awaiting surgery, in cases where surgery is not indicated, when patients do not want surgery or cannot undergo surgery under general anesthesia.
What is the procedure for epidural steroid injection?
Epidural steroid injection is administered in the operating room, under the control of an X-ray machine. The use of an X-ray machine is necessary if the procedure is to be performed correctly. Without the use of an X-ray machine, the percentage of improperly performed injections is up to 30% even with experienced doctors. The epidural space can be accessed in three ways: interlaminar, transforaminal or caudal, which depends on the indication for the injection and the exact place in the epidural space where the drug is to be administered.
The patient lies on the operating table prone or on his side, depending on whether the injection is given in the cervical or lumbar epidural space. The skin and subcutaneous tissue are infiltrated with a local anesthetic, then the needle is introduced into the epidural space under the control of the X-ray machine. The position of the needle is confirmed by the application of contrast, then the drug is injected and the needle is removed.
The duration of the procedure is about 30 minutes, after which the patient goes to the observation room, where he stays for at least another 30 minutes.
When the doctor is sure that the patient is fine and that there are no allergic reactions to drugs or other complications, he is discharged home accompanied by a responsible and adult person, who will take the patient home.
Patient behavior after epidural steroid injection
On the day of the injection, the patient should rest. If he/she does a physically demanding job, the rest should last 24-48 hours. After that, it is allowed to return to earlier activities. A control examination is usually scheduled 14 days later, in order to evaluate the effect. If the first injection does not reduce the pain, there is a chance that the second or third one will. However, if the pain decreases after the first injection, it makes sense to repeat the injection if necessary, at intervals of no less than 2 weeks.
In a year, the patient can receive a maximum of 3-4 epidural injections.
What is the effectiveness of this treatment for painful conditions of the spine?
The percentage of success of all epidural injections ranges between 70% and 80%, provided that they are carried out with X-ray control.
The best results are achieved with radicular pain due to disc herniation, in the early stages of the disease and in patients with long-term complaints, previous spinal operations, for whom surgical intervention is not possible.