Frequently Asked Questions (FAQs)
Epidural Steroid Injection - Patient Information
The following Frequently Asked Questions and the answers are
for the Lumbar Epidural Steroid Injection. It is one of the most common procedures
performed in this pain clinic. The following material is given as general
information only, and is not to be considered as medical advice or
consultation.
What is an Epidural Steroid Injection?
What is the purpose of it?
How does an Epidural Steroid Injection
work?
How long does the injection take?
What is actually injected ?
Will the injection hurt ?
Will I be "put out" for this
procedure?
How is the injection performed?
What should I expect after the injection
?
What should I do after the procedure ?
Can I go back to work the next day?
How long the effect of the medication
lasts?
How many injections do I need to have?
Can I have more than three injections?
Will the Epidural Steroid Injection help
me?
What are the risks and side effects?
Who should not have this injection?
How should I prepare for the procedure?
The spinal cord runs within the bony structure of the
vertebral column and is encased by a membranous sac called the dural sac. This
sac contains spinal fluid that bathes and nourishes the spinal cord. The
epidural space is the space between the outer surface of the dural sac and the
bones of the vertebral column. Nerves from the lower limbs (including the
sciatic nerve) enter the vertebral column and pierce the dural sac to reach the
spinal cord. For various reasons these nerves can become irritated as they
enter the vertebral column and cause pain in the lower limbs. This pain is felt
as shooting down the lower limb and is referred to as nerve root pain or,
technically, radicular pain (from the Latin radix, a root). The common name for
this sort of pain is sciatica.
The term, ìepidural
steroid injectionî refers to the injection of corticosteroids into the
epidural space of the vertebral column as a means of treating pain caused by
irritation of the spinal nerves.
Injection of saline, anesthetic, and/or steroids into the epidural
space decreases lower back pain and sciatica by the following proposed
mechanisms. Injection of large volumes of saline alone purportedly lyses
adhesions (loosening scar tissue). Injection of local anesthetic agents may
provide temporary relief from nerve root inflammation by decreasing the
sensations arising from the inflamed tissue or even long‑term relief by
breaking the pain cycle. Addition of steroid to the anesthetic decreases
inflammation in the epidural space.
Epidural injections of local saline‑anesthetic‑steroid
mixtures are most effective for the treatment of nerve root entrapment and
irritation secondary to discogenic disease after failure of other conservative
treatment and when surgical treatment is under consideration. The technique has
been extended for treatment of multiple etiologies such as spondylolisthesis,
degenerative arthritis or pain due to posterior rami with equivocal results.
Epidural injections are also commonly given for relief of pain in post‑laminectomy
patients. The procedure is performed on an outpatient basis by
anesthesiologists and administered close to the site of nerve root involvement.
The injection technique is described as follows: The patient is placed in the
sitting position and the lumbar area is scrubbed and prepped with an Iodine
based agent (other antiseptics can be used in case of iodine allergy). When
using radiological guidance, it is actually easier to perform the procedure
with the patient lying down on his/her stomach. The skin is then numbed using a
local anesthetic (lidocaine). The epidural puncture is done close to the site
of the nerve root lesion. A local anesthetic is injected to provide temporary
pain relief and in an attempt to break the pain cycle. In addition to the local
anesthetic, a steroid is injected slowly in the epidural space. Following
epidural steroid injection, a catheter can be introduced to inject another dose
of steroid and local anesthetic, if needed to reach the appropriate nerve root.
There are some proponents of the use of fluoroscopic guidance in administration
of the injection. White found 25% of injections were not epidural even when
performed by a skilled anesthesiologist. Renfrew reported that over a 1-year
period, 316 caudal‑approach epidural injections were evaluated with
fluoroscopy and contrast administration for correct placement of the needle in
the epidural space. The initial placement of the epidural needle was correct in
only 48% to 62% of injections depending on the experience of the physician. He
concludes that correct placement requires radiographic corroboration. A similar
study has not been completed for lumbar epidural injections.
Epidural Steroid Injection is an injection of long lasting
steroid ("Depo-Medrol/Triamcinolone/Celestone") into the Epidural
space, the area which surrounds the spinal cord and the nerves coming out of
it. All of the nerve roots in the spine are covered with a protective sheath
called the DURA. When a prescribed amount of a long‑acting local
anesthetic agent (MARCAINE 0.25%) combined with a "steroid‑type"
agent (Depomedrol, Triamcinolone, or Celestone) is injected adjacent to the
affected nerve root(s)'s dura, significant pain relief is often obtained. This
is performed by a Board Certified Anesthesiologist, with subspecialty training
in Pain Medicine. Anesthesiologists are trained early in their careers in the
use of epidural placement techniques, which they then use on a daily basis to
administer regional anesthesia in the operating room, and in the obstetric
units to provide analgesia for deliveries of babies. Their extensive experience
with this technique, makes them specially suited for this procedure.
The steroid injected reduces the inflammation and/or
swelling of nerves in the Epidural space. This may in turn reduce pain,
tingling & numbness and other symptoms caused by nerve inflammation /
irritation or swelling. It also serves a diagnostic purpose in which the
physician can obtain significantly useful information, depending on the
patientís response. Epidural Injections are often recommended as an
alternative, or at least an attempt to ward off the need for surgery. You may
also have a condition in which surgery would never be of benefit, and epidural
injections may provide an alternative form of treatment.
There are two ways, in which it is thought that epidural
steroid injections may work. The first belief is that some leg pain involves
the inflammation of one or more nerves, their covering, or their roots, in the
back. The injection of steroids directly into the part of the spinal column
called the epidural space is thought to aid in reducing this inflammation. The
other belief is that the corticosteroids act like a local anaesthetic and block
the pain, long enough to allow the body to begin the process of repairing
itself. The chief effect of an epidural steroid injection is to reduce pain.
Relief could last weeks, months, or even years. On the other hand, some
patients experience no relief of the pain.
The actual injection takes only a few minutes.
The injection consists of a mixture of local anesthetic
(like lidocaine or bupivacaine) and the steroid medication (triamcinolone, Depo‑medrol,
Celestone).
The procedure involves inserting a needle through skin and
deeper tissues (like a "tetanus shot"). So, there is some discomfort
involved. However, we numb the skin and deeper tissues with a local anesthetic
using a very thin needle prior to inserting the Epidural needle. In fact, the
worse part is usually the injection of the numbing medicine, which will feel
similar to a Bee sting. Most of the time you will feel a strong pressure and
not much pain.
No. This procedure is done under local anesthesia. Doing
this procedure with the patient under general anesthesia or heavily sedated is
contraindicated since it can lead to serious complications.
It is done either with the patient sitting up, on the side,
or if using radiological guidance, on the patient's stomach. The patients are monitored
with EKG, blood pressure cuff and blood oxygen-monitoring device (Pulse
Oxymeter). The skin in the back is cleaned with antiseptic solution and then
the injection is carried out. After the injection, you are placed on your back
or on your side, until you feel ready to stand up.
Immediately after the injection, you may feel your legs
slightly heavy and may be numb. Also, you may notice that your pain may be gone
or quite less. This is due to the local anesthetic injected. This will last
only for a few hours (4-6 hours). Your pain will return and you may actually
have more pain than usual for 5 to 6 days. This is due to the mechanical
process of needle insertion as well as initial irritation form the steroid
itself. You should start noticing pain relief starting the 5th to 6th
day or so. Although the steroids will begin to work immediately after
injection, it will take 5 to 6 days for the swelling to come down to the point
where you will be able to tell a difference. Please remember that this is what
takes place on the average patient, meaning that there are some that get the
relief sooner, while there are others that takes them up to ten days to see any
benefits.
You should have a ride home. We advise the patients to take
it easy for 24 hours or so, after the procedure. Perform the activities as
tolerated by you. It is recommended that you apply Ice (wrapped on a towel) to
the injection site on the day of the procedure. This is done to minimize
swelling from the procedure itself. The next day, you should apply heat
(heating blanket or other source of mild heat) to the area, which tends to cut
down on recovery time and discomfort.
You should be able to, unless the procedure was complicated.
Expect to be very ìsoreî for approximately 4 to 5 days.
The immediate effect is usually from the local anesthetic
injected. This wears off in 4 to 6 hours. The steroid starts working
immediately after being injected, but most patients cannot feel a difference
until 5 to 6 days after the injection. Its effect can last for several days to
a few months.
If the first injection does not relieve your symptoms in
about a week or two, you may be recommended to have one more injection. On the
other hand, if you obtain 100% relief with the first injection, the others are
not necessary. Similarly, if the first injection provides you with partial
relief, you may be recommended to have another, until a maximum benefit is
obtained, or a total of three injections are achieved. It is recommended that
no more than three injections be done in a six-month period, or six in a one-year
period. It is also not recommended to continue with injections for more than a
year, if no long-term relief is achieved.
In a six-month period, we generally do not perform more than
three injections. This is because the medication injected lasts for about six
months. If three injections have not helped you much, it is very unlikely that
you will get any further benefit from more injections. Also, giving more
injections will increase the likelihood of side effects from the steroid.
Generally most arthritic conditions of the back, with or
without nerve‑root symptoms (leg pain), will obtain varying degrees of relief.
This is similar to knee or shoulders injections. Overall, approximately 50 ‑
75% of patients receive moderate to excellent pain relief. The relief is often
permanent, especially in self‑healing conditions such as mild
"bulging" discs. For more severe pathology, relief is indirectly
proportional to the amount of time that the patient has suffered the condition.
In cases of severe nerve root compression syndromes, the therapeutic pain
relief will often be very brief! In cases of mechanical compression of a nerve,
only mechanical decompression through surgery may help. For other conditions,
especially arthritic induced pain, 2 to 3 months of relief can be seen. A trial
of TWO may be given, but usually no more than THREE are recommended over a
six-month period.
Raj reviewed 15 studies completed in the time period 1944 to
1977 for the efficacy of epidural injections. Of the 10 groups who reported
treating more than 25 patients, a range of 39‑81% of the patients
received complete or significant relief of pain (mean of 62%).
It is very difficult to predict if the injection will indeed
help you or not. Generally speaking, the patients who have "radicular
symptoms" (like sciatica) respond better to the injections than the
patients who have only back pain, although certain types of back pain seem to
obtain considerable benefit from the injections. Similarly, the patients with a
recent onset of pain may respond much better than the ones with a long-standing
pain. Also, the patients with back pain mainly due to bony abnormality may not
respond adequately.
Generally speaking, this procedure is safe. However, with
any procedure there are risks, side effects, and possibility of complications.
The most common side effect is back pain and spasms, which tend to be
temporary. Other risk include; spinal puncture with possible spinal headaches,
infection, bleeding inside the Epidural space, nerve damage, worsening of
symptoms, etc. In the case of bleeding, this is more common in patients with
genetic predispositions, such as hemophilia, or on patients taking blood
thinners such as aspirin, Coumadin, ticlid, levenox, or any other form of
antiplatelet medication. The problem with bleeding into the spine is that it
may accumulate, causing compression of the spinal cord with resultant
paralysis. This would require an emergency surgery to decompress, and there
would be no guarantees that you would recover. In the case of infection, the
same holds true with the possible development of an abscess inside of the
spine. Other types of infection would also include meningitis, which can be
fatal.
Risks and side effects related to the medications include;
weight gain, increase in blood sugar (mainly in diabetics), water retention,
suppression of the bodyís own natural production of cortisone, temporary
suppression of the immune system, etc. Minor side effects are seen in 1 to 2%
of patients and are as follows: Puffy cheeks and weight gain, swelling in the
ankles from fluid retention. Because the injection occurs next to an inflamed
nerve root, sensations of temporary increased pain, numbness in one or both
legs, and difficulty voiding can occur. More rare side effects can occur and
include steroid myopathy (weakness of the thigh muscles), temporary steroid
psychosis, possible worsening of osteoporosis if present, permanent
incontinence, and congestive heart failure.
Possible side effects of the steroid medications include
facial redness, occasional low grade fevers, hiccups, insomnia, headaches,
increased heart rate, and abdominal cramping or bloating. These side effects
occur in only about 5% of patients and commonly disappear within 1-3 days after
the injection.
By statistics, you have more of a chance of getting killed
in a motor vehicle accident on your way to the hospital, than any of these
things happening. Nevertheless, they have been described before, therefore,
they can happen. You should look at this, similar to ìtaking a showerî.
Everybody knows that you can slip, hit your head, and get killed. This does not
mean that it happens often enough that you should worry about it, and it certainly
does not mean that you should never shower again, just because it may happen.
If you are allergic to any of the medications to be
injected, if you are on a blood thinning medication (e.g. Coumadin, Ticlid, or
a daily aspirin or aspirin containing medication), patients with bleeding
disorders (Hemophilia, thrombocytopoenia, or any other coagulopathies), or if
you have an active infection going on, you should not have the injection.
…
Do not eat or drink anything for at least 6 (six) hours
prior to the procedure. An exception to this would be taking your medications
with just a sip of water. (Beware of blood thinners. Tell your physician about
it!)
…
Always come accompanied by a responsible adult, who will
serve as a driver after the procedure. Remember that your legs may get numb and
you will not be able to drive. (A taxi will not do!)
…
Stop any blood thinners at least 5 days prior to your
procedure. Always consult your primary care physician before stopping these
medications. (Aspirin or aspirin-containing medications will need to be stopped
11 days prior to the procedure)
…
Dress in a fashion where it will be easy to expose your
back, without the need to completely undress you. Do not bring expensive
clothing that can be ruined by our cleaning solutions (Iodine).
…
If you have a cold or an active infection, please call our
clinics and reschedule the procedure for a latter time. Remember that the
steroids will temporarily depress your immune system, which may lead to a
full-blown pneumonia if you have an upper respiratory infection (a cold).
In an attempt to explain the variation of success rates of
epidural injections, Brown studied the effect of chronic illness
retrospectively. He selected 56 cases felt to be unquestionably
"discogenic" from the original series of 100 cases in Dilkes study
into acute versus chronic on the basis of acute being symptoms less than 3
months and chronic symptoms longer than 3 months. He also grouped patients with
or without previous surgery. Using a follow‑up period of 6 to 40 months,
Brown concluded that patients with classic discogenic syndromes with symptoms
less than 3 months duration have excellent chance for symptomatic relief by
epidural steroid injections but have a lesser effect on patients with symptoms
persisting for periods longer than 3 months or in patients treated previously
by surgical methods. A retrospective analysis reported by Cousins described
better results in patients who had not previously undergone surgery, patients
with "acute" versus "chronic" complaints, and patients with
histories shorter than 12 months (three studies), six months (one study), three
months (four studies), or 2 months (one study). In a study of 249 chronic low
back pain patients that assessed their pain intensity before, 1 day after, and
2 weeks after receiving a lumbar epidural steroid injection (LESI) using a
comprehensive pain questionnaire and the Brief Symptom Inventory (BSI), Jamison,M.D.
identified four factors that best predicted poor outcome 2 weeks after the
LESI: "a greater number of previous treatments for pain, more medications
taken, pain not necessarily increased by activities, and pain increased by
coughing." Factors that predicted no benefit one year after treatment
included: "pain that does not interfere in activities, unemployment due to
pain, normal straight‑leg raise test prior to treatment, and pain not
decreased by medication."
Conclusions Raj,M.D. made after reviewing the studies are;
"Two thirds of patients with acute discogenic disease will benefit from
epidural steroids. Only one third will benefit after 6 months." Raj
recommends that two weeks after the epidural steroid injection the patient be
reevaluated. "If there is significant improvement in function and
subjective pain relief, no further epidural injection is administered. However,
if after the first injection the initial improvement is not maintained,
additional injections can be repeated two weeks apart to a maximum of three. If
there is no change in the patient's condition after the first injection,
alternative methods of pain relief are sought. These recommendations are
supported by Cousins,M.D.. Because steroid injection is often the last recourse
before consideration of back surgery with its much higher risks and costs, and
because some patients do experience significant relief of pain, the benefit of
up to three injections separated by time intervals of one to two weeks for
evaluation of effectiveness would appear to offset the potential risk and
costs.