Epidural spinal injection is a non-surgical treatment option utilised for relieving back pain. Spine degenerative conditions such as herniated disc, spinal stenosis and many others may induce back pain due to the compression of the associated spinal nerves. This pain or numbness may extend to the other parts of the body such as hips, buttocks, and legs. Doctors start with non-surgical methods to treat back pain and epidural spinal injection is one of these preferences. In cases where the patient finds no relief from non-surgical methods then finally surgery is recommended.
Epidural spinal injections contain a strong anti-inflammatory agent called corticosteroid and an anaesthetic for pain relief. It is not the same as epidural anaesthesia given before childbirth to decrease labour pain. Epidural injections are administered into the epidural space of the spine. The epidural space is the space between the outermost covering of the spinal cord (dura mater) and the wall of the spinal canal. It is approximately 5mm wide and is filled with spinal nerve roots, fat and small blood vessels.
An epidural spinal injection may be employed both for diagnostic and therapeutic reasons, including:
- Medications to determine the specific nerve root involved in the spinal problem (diagnostic purpose)
- Medication for inducing short or long-term relief from pain and inflammation (therapeutic purpose)
It is to be noted that epidural spinal injection is not a curative intervention; rather it’s a treatment tool to reduce the discomfort of the patient so that rehabilitation programs such as physical therapy may be well executed.
Pain management in different conditions such as spinal stenosis, disc herniation and arthritis can be done through epidural injection. Different types of physicians such as physiatrists, anaesthesiologists, radiologists, neurologists, and surgeons may recommend epidural injections for pain relief.
Usually epidural spinal injection is done on an outpatient basis. The procedure involves the following steps:
- Patient is taken to the pre-op area where trained nursing staff prepares the patient for the procedure by taking vitals and reviewing medications. Blood sugar and coagulation status may also be checked if needed.
- Patient is taken to the procedure room and will lie face down on a table.
- The injection site is then cleansed and injection of a local numbing agent is given in the area so that you don’t feel pain during the procedure.
- A thin hollow needle is then inserted into the epidural space, guided by fluoroscopic X-ray to place the needle in the correct position. This system gives real time X-ray images of the position of the needle in the spine on a monitor for the surgeon to view.
- A contrast material is then injected through the properly placed hollow needle to confirm that the drug flows to the affected nerve when injected.
- When the doctor is satisfied with the position of the needle, the anaesthetic drug and corticosteroid are injected through the same needle inserted in the spine.
- Finally, the needle is removed and the injection site is covered with a dry, sterile bandage.
Patients may feel some pressure during the injection, but mostly the procedure is painless. The procedure takes about 15-30 minutes to complete. After injection, the patient should not drive or go back to work and should rest and avoid any vigorous activities. Your surgeon may give specific post-care instructions. Please follow the instructions to recover faster.
Patients may feel numbness in the arms or legs just after the procedure along with other side effects related to the anaesthetic component that usually settles down within 1-8 hours. Patients may continue to feel some back pain, as epidural spinal injections take about 24-72 hours before showing their pain-relieving action. In some cases, if the desired effect is not obtained, then reinjection may be recommended. The standard guidelines for steroid injections state a maximum of 3 injections per year. In case no relief is obtained from spinal injection, then surgery is considered as the final option.
Risks and complications
As with any procedure, certain risk factors are always present. Likewise, epidural spinal injections have complications such as bleeding or infection at the injection site, pain during or after injection, post-injection headache, nerve injury, bladder dysfunction, fluid retention, respiratory arrest, epidural hematoma, and spinal cord infarction. Discuss with your doctor if you have any concerns prior to the procedure.