An epidural is a regional anaesthetic which is given through
a needle and catheter (a fine tube), into the epidural space
by a qualified doctor.
The epidural space, is sometimes
referred to as the extradural space, it is situated in the
spinal canal before the spinal cord, cerebrospinal fluid and
duramater. The epidural space contains soft-tissue and veins.
The purpose of an epidural
is to help lower pain sensation, and is most commonly given
during childbirth, pre-operatively to be used as a post-operative
pain relief and as anaesthesia for Caesarean section.
When an epidural is used to
manage chronic back pain, the solution injected is a mixture
of analgesics and steroids.
An epidural has to be given
by an anaesthetist who will feel for the right space between
the vertebrae (which is made easier by positioning the patient
suitably), and using a sterile method the anaesthetist will
administer a local anaesthetic to numb the skin area before
inserting a guidance needle to find the epidural space.
When the space is found,
a very fine tube is passed and the drugs are injected. The
tube can be left inside which is connected to a machine that
will administer the solution at intervals set by the anaesthetist.
An epidural is usually given
in the mid-lumbar or lower back as the spinal cord ends at
the 1st lumbar vertebra, under which is the cauda equina,
(a bundle of nerves that branch off in different directions).
The risk of spinal cord injury is lowered when an epidural
is given in this way.
Indications of Epidural
Use for Back Pain
Epidurals are helpful in managing
back pain if caused by herniated discs, degenerative disc
diseases or for spinal stenosis. Epidurals have a 50% success
rate. In combination with an exercise programme you can achieve
results such as lowered irritation to the spinal nerves and
a decrease in swelling.
This method is only a temporary
pain relief, which can last from one week to a year; it lets
the patient use that time taking part in other rehabilitative
A course of 3 treatments is usually needed but if the first
one treatment is totally unsuccessful and no benefit has been
gained, there is no reason for carrying on with the remaining
of an Epidural
The effects required from
an epidural are lowered feelings, lowered pain awareness and
loss of muscle power (if required for surgical anaesthesia).
Other side-effects can include
a fall in blood pressure, as loss of control of parts of the
central nervous system, including that which controls blood
pressure and headaches are caused by the epidural. ‘Epidural
headaches’ are caused when the cerebrospinal fluid leaks
out of its space.
The needle or catheter may
be misplaced into a vein; if this occurs it is not very serious
but can cause unnecessary distress for the patient. Now and
again though, the level of block can be a little higher up
the spinal column than expected, patients will need to be
closely watched until it has come down to an satisfactory
• Patients who have
bleeding disorders should not be given epidurals, unless adequate
time has been given to adjust existing medications.
• Epidurals should not be given through a place of infection
or broken or bruised skin.
• There are certain conditions such as spina bifida,
scoliosis or previous spinal surgery which may make administration
particularly hard so may have to be avoided.
Epidurals can be a very efficient
way of controlling chronic back pain. Therefore the benefits
can allow patients to try other longer-term therapies to better
their chances of being pain free in the future.