EPIDURAL BLOCK
Anatomy
İİİİİİİİİİİİİİİ The spinal epidural
space extends from the base of the skull to the sacral hiatus. It is
composed of fatty tissue, lymphatics and blood vessels. The epidural space surrounds
the nerves as they exit the spinal cord. In some patients the nerves can be
compressed and inflamed by a bulging disc or a tight spinal canal (spinal
stenosis). By injecting steroids into the epidural space, we can bring
irritated nerves into direct contact with a potentially helpful medication. These
steroids act directly on the irritated nerves and can reduce swelling and
inflammation, which often leads to decreased pain. Epidural steroids may be
injected anywhere along the spine from the neck to the low back depending upon
the location of your pain.
İİİİİİİİİİİİİİİ After numbing the
skin with local anesthetic (like novocaine), a small needle is passed into the
epidural space slowly. You may experience a sensation of pressure while this is
being done. As the medication is being injected, you will be asked to inform
the physician if you develop any ìringingî in your ears, or a ìmetallicî taste
in your mouth. If you do, immediately notify the physician as he/she may want
to ask some further questions. As the medicine is being injected into the
epidural space, you may also feel pressure building up. This may not happen at
all, and it is entirely dependent on how much swelling there is within the
epidural space (the more swelling, the more pressure). If you begin to feel
this pressure, notify the physician and he/she may slow down the rate at which
the medicine is being injected, which will allow for this pressure to dissipate.
Preparation for an Epidural Steroid Injection
- Do not eat
for at least 6 hours prior to your appointment. This
safety measure keeps food out of the stomach, which could otherwise be
vomited into the lungs during an adverse reaction.
- You may drink small amounts of
water, up to two (2) hours prior to your procedure.
- The morning of your procedure take
a good shower with an antibacterial soap. Brush your teeth and rinse with
an antibacterial mouthwash. Use a deodorant but avoid using perfumes. Remove
any nail paint. Do not smoke.
- You may take your regular
medications, including pain medications, with a sip of water
before your appointment. Diabetics
should hold regular insulin (if taken separately) and take ‡ normal NPH
dose the morning of the procedure. Carry some sugar containing
items with you to your appointment.
- You must be
accompanied by a person who can drive you home. This
person should also be strong enough to assist you, in the event that you
develop any numbness or weakness. You may be given sedation which alters
your driving abilities; you could injure or kill yourself or someone else
should you try to drive.
- Bring all
of your current medications with you.
- An IV may
be inserted and light sedation may be given at the discretion of the
physician.
- A blood
pressure cuff, EKG and other monitors will often be applied during the
procedure. Some patients may need to have extra oxygen administered for a
short period.
- You will be
asked to provide medical information, including your allergies, prior to
the procedure. We must know immediately if you are taking blood thinners (like Coumadin / warfarin, Ticlid
/ ticlopidine, Plavix / clopidogrel, aspirin, Googy powders, Lovenox, etc)
or if you are allergic to IV
iodine contrast (dye). We must know if you could possibly be pregnant. We
must also know if you are taking
metformin (Glucophage, Glucovance, Duformin, Orabet, Glucamet),
prior to using any radiological contrast. If you are taking metformin, it
is necessary for you to stop taking it for a few days after the injection
of radiological contrast. This is to avoid the build up of acid in the
blood. Stopping the tablets will not cause any harm to you. After the
procedure, you will need to contact your primary care physician (PCP) or
general practitioner (GP) to arrange for a blood test to determine whether
it is safe to start taking your tablets again, and to check on your blood
sugar. This blood test is usually performed 48-72 hours after the
procedure.
- You will
need to read and sign a consent form for the procedure prior to being
sedated.
- You may be
asked to sit up for the procedure or lie on your stomach, or either side,
with your legs and back curled up. This will help entry of the
needle into the epidural space.
Indications for Having an Epidural
- Acute pain
- including such things as postoperative pain, trauma, fractured ribs,
pancreatitis, shingles, ischemic vascular pain and ureteric colic.
- Chronic
pain:
-
Low back pain and/or leg pain
-
Neck pain and/or arm pain
-
Spinal Stenosis
-
Post-laminectomy syndrome
-
Pain from compression fractures
-
Post herpetic neuralgia
-
Reflex sympathetic dystrophy (Complex Regional Pain
Syndrome)
-
Phantom limb pain.
Benefits
The introduction of anesthetics and steroids into the epidural space may
reduce pain and inflammation around nerve roots or bulging discs. It takes 5-10
days for benefits to appear.
Efficacy
|
Duration of Back Pain
|
Success Rate (%)
|
|
< 3 Mo.
|
83-100
|
|
= 6 Mo.
|
67-81
|
|
= 1 yr.
|
69
|
|
> 1 yr.
|
46
|
|
|
|
Possible factors
influencing response:
- diagnosis of
root inflammation
- duration of
symptoms
- previous surgery
(decreases response)
- Age (increased
age, decreased effectiveness)
- Location of
injection (at site of inflammation)
- Work relation of
injury
Possible Side Effects
- Bleeding from needle site
- Infection (rare, may require
surgery) Minor infections occur in 1% to 2% of all injections. Severe
infections are rare, occurring in 0.1% to 0.01% of injections
- Nerve injury (rare)
- Numbing
& tingling (temporary)
- Difficulty
urinating (rare, temporary)
- Spinal
headache (a headache worse with upright posture) (0.5-1.0%)
- Light
headedness (temporary)
- Pain
at injection site (several days)
- Decreased
blood pressure (temporary)
- Weakness
in arms / leg (temporary)
- Pressure
sensation in back / neck (temporary)
- Suppression
of natural steroids (cortisol) for up to 3 month (temporary)
- Fluid
retention (temporary)
- Difficulty
breathing (go to emergency room, have physicians there notify us)
- Swelling
of the face or other parts of the body (temporary)
- High
blood pressure (temporary)
Possible Risks
The total complication rate
after epidural steroid injections (including minor complaints such as facial flushing, transient
increase in blood sugar level, and transient increase in low back pain) is 9.6%.
The epidural steroid block can be safely
performed as an outpatient at the Pain
Control Center.
However, certain complications may occur. These include backache,
headache, inadvertent spinal block, permanent nerve damage, convulsions,
hematoma at puncture site, epidural hematoma, epidural abscess, meningitis,
paralysis, respiratory and/or cardiac arrest, and death. Even though
these complications are rare, resuscitative equipment as well as experienced
doctors and nurses are always close by to handle these emergency situations.
Frequency of Treatment
Epidural injections are often repeated at two-week intervals for best
effects. A maximum of three blocks are performed in any series.
This can be repeated after 6-12 months should your doctor feel another series
would be beneficial.
Things to Expect After Block
- Your blood
pressure may decline. Usually your IV fluid intake will counteract
this but there are other medications that will keep it from dropping
significantly.
- Some
numbness or weakness may be felt in your legs but this is temporary and
will resolve in 4-6 hours.
- Some
soreness at needle insertion site can be expected. In fact, you may
experience more pain than usual for a period of 5 to 10 days. Tylenol and
a heating pad may be beneficial.
- Difficulty
with urination - again this is a temporary side effect and will resolve in
about 4-6 hours. If you are unable to void after 6 hours, you should
go to the nearest Emergency Room, and have their physician give us a call.
Things You Can Do
to Aid in Your Care
- Get 8 hours
of sleep at night and eat 3 well-balanced meals.
- Avoid
lifting heavy objects and use your legs when lifting anything.
Call if you experience:
- Fever / chills associated with
headaches or increased back / neck pain
- Headache worsened by an upright
position
- New onset weakness or numbness
of an extremity below the injection site.
- Progressive numbness or weakness
of an extremity below the injection site. (You may experience some
weakness and numbness after a block, nevertheless, this improves and wears
off as time passes. If instead of improving or wearing off, it worsens, go
to your nearest emergency room and have them give us a call).
- Hives or difficulty breathing
(go to emergency room)
- Unable to urinate for more than
4-6 hours after the procedure, despite adequate hydration. (go to
emergency room)
- Inflammation or drainage of the
injection site.
- Severe back / neck pain
- Any new symptoms which are
concerning to you
Please Note
- Steroids may increase blood sugar levels after
procedure.
If you are a diabetic, blood sugar may need to be monitored and
medications possibly adjusted. Please make sure to notify your primary
care physician (PCP).
- Although the injected local
anesthetics can often make your back or neck feel good for several hours
after the injection, the pain will likely return. It takes 5-10 days for
steroids to work in the epidural space. You may not notice any pain relief
for at least that one week.
- If effective, we will often do a
series of three injections spaced 2-6 weeks apart to maximally decrease
your pain. After the initial series, we generally will wait several months
before considering a repeat injection of the same type.
If you have any questions, please
call (336) 538-7180
Alamance Regional
Medical Center
Pain Clinic