5 Things to Know About Epidural Steroid Injections
/By Margaret Aranda, MD, Columnist
Some patients with neck and back pain report that their doctor requires them to get epidural steroid injections (ESI's) before they are prescribed opioid pain medication. Many do not realize that the procedure or any use of drugs for spinal injection is not FDA approved and is considered "off label."
Some patients benefit from ESI’s, while others gain no pain relief or suffer serious complications. In 2014, the FDA warned that injection of corticosteroids into the epidural space of the spine may result in rare but serious neurological events, including "loss of vision, stroke, paralysis, and death."
A 2015 commentary by FDA scientists in The New England Journal of Medicine urged doctors to carefully select patients to identify those who might benefit from spinal injections and to minimize serious risks.
Probably the worst epidural steroid catastrophe was the 2012-13 outbreak of fungal meningitis, caused by contaminated steroids produced at the New England Compounding Center. As many as 13,000 patients nationwide were exposed to the fungus, mostly through epidural injection, resulting in 751 meningitis infections and at least 64 deaths.
Let's take a step back to assess why epidural steroids may or may not be a good idea. The rationale behind the procedure comes from the anti-inflammatory effect of steroids on the nerves.
Chronic inflammation in nerves can lead to pain, numbness, and muscle weakness. Nerve injury causes microscopic changes in nerve anatomy, including tissue swelling or edema, an increase in fibrous tissue and, in the worst case, nerve death through something called Wallerian degeneration. In cases like traumatic brain injury or stroke, the nerve damage can be permanent.
There are now about 9 million epidural steroid injections performed annually in the U.S and the number of procedures appears to be growing.
During a standard epidural injection, the doctor may inject into the epidural space a contrast dye using x-ray guidance (fluoroscopy) to make sure the dye is going into the correct location. Others may use a more blind approach, called the "loss of resistance" technique, with a syringe of air that injects itself into the epidural space as it enters. There is a "pop" when the needle penetrates the epidural space.
After the air or dye is injected and the needle located, a second syringe containing the steroid is injected. Afterward, the patient is observed for signs of pain relief and complications.
Many studies show that about 50% of patients feel better. If there is no pain relief after one ESI, a second attempt is usually in order. If partial relief is exhibited, a series of three injections in two weeks may be performed.
There is controversy over the rate and frequency of epidurals for pain. Typically, a “cycle” of epidurals is done, but if there is no pain relief after two injections, some doctors recommend that a different treatment be used. Some patients report getting as many as two or three dozen epidurals in a single year. Critics say that raises the risk of a misplaced needle causing “cumulative trauma” and serious complications such as adhesive arachnoiditis.
If you doctor recommends that you get an epidural steroid injection, here are five things you need to know:
1. Drugs Used: The two most common drugs for ESI are a local anesthetic (lidocaine or bupivacaine) and/or a corticosteroid (betamethasone, dexamethasone, hydrocortisone, methyl-prednisolone, triamcinolone).
The local anesthetic offers immediate numbing and pain relief. It also verifies whether the injection was done in the right place and gives an idea of how the steroid may act to decrease inflammation. After the anesthetic wears off, the steroid kicks in for an effect that may last varying times, sometimes for a short period and sometimes forever.
Patients and doctors need to know whether there was immediate pain relief from the local anesthetic. The doctor should ask, "Does the pain feel better?" to assess the temporary anesthetic effect.
If the answer is yes, then the steroid should provide more pain relief. If the answer is no, the steroid is much less likely to have any clinical effect. There is no indication to repeat the procedure if there is no decrease in pain. Doing so would unnecessarily expose a patient to serious complications or death.
2. Injection Sites: The most common injections are into the neck (cervical) and into the lower back (lumbar). Less commonly, epidural injections are placed into the upper back (thoracic) or to the bottom tip of the spine in the sacral area (caudal). The needle can go either straight into the middle of the spine (interlaminar), or enter from the left or right side (transforaminal).
In general, the closer the injection is placed to the head, the greater the risk of serious complications if the needle accidentally hits a nerve or artery, an air bubble causes an embolism, or if the injection goes into the spinal fluid.
3. Minor complications: Adverse events can occur within minutes or up to 48 hours after an injection. Minor complications are generally not life-threatening and usually go away with little to no treatment.
Some patients get an "epidural headache" when the needle is inserted too far into the dura, causing a leak of cerebrospinal fluid. This is a stressful and painful headache, but it usually completely resolves. Other minor complications include facial flushing, fainting, hypertension (high blood pressure) and increased pain.
4. Serious complications: No one really knows the complication rate of epidural steroid injections, due to under-reporting by doctors and the lack of standard guidelines.
Normally, the steroid will flow into the epidural space above and below where it was injected, but it can also flow into unintended places like the subdural or intrathecal spaces, cranial nerves, brain stem, and lower midbrain.
For example, if the injection accidentally goes into the spinal fluid, the procedure becomes a spinal block, not an epidural block. This may lead to potentially life-threatening complications. If this happens during an injection to the neck, it can spread upward, toward the top of the head and into the brain, leading to serious complications.
Severe complications from an injection can include arachnoiditis, allergic reactions, stroke, brain edema, cauda equina syndrome, seizures, vasculitis, blindness, and death.
5. Off-Label Use: The FDA places epidural steroids in the category of "off-label" use that falls within the practice of medicine and is not FDA-approved. The FDA requires all glucocorticoid steroid warning labels to state:
The safety and effectiveness of epidural administration of corticosteroids have not been established and corticosteroids are not approved for this use… serious neurologic events, some resulting in death, have been reported with epidural injection of corticosteroids.”
The FDA website also warns patients to seek emergency medical attention if they experience any unusual symptoms, such as loss of vision or vision changes, tingling in the arms or legs, sudden weakness or numbness, dizziness, severe headache or seizures.
If you have concerns regarding the use of epidural steroid injections, talk to your doctor.
Dr. Margaret Aranda is a Stanford and Keck USC alumni in anesthesiology and critical care. She has dysautonomia and postural orthostatic tachycardia syndrome (POTS) after a car accident left her with traumatic brain injuries that changed her path in life to patient advocacy.
