Download Patient information sheet: Epidural block under CT control (lumbar

Patient information sheet: Epidural block under CT control (lumbar spine)
Aim of the epidural block
An appointment has been made for you by your physician for a so-called epidural block under CT control. “Epi”
stands for “in the surrounding area of”, and “dural” for the tube of tough connective tissue, which lines the spinal
canal. This tube is filled with fluid and contains the nerve roots.
A discal hernia or also changes within the context of arthrosis can press from the outside onto this dural tube.
With an epidural block, a needle is introduced as near as possible to this diseased process, in order to inject
anti-inflammatories and local anaesthesia.
Example of a patient lying on their front. The magnetic resonance imaging (MRI) image on the left shows a discal hernia
(broken line), which is pressing onto the dural ‘tube’. In the image on the right (computerised tomography [CT]), thanks to the
dye (marked with arrows), it is possible to recognise where the injected drug is located, i.e. directly behind the hernia (shown
with a broken line, as in the MRI image).
Precautionary measures
Please notify us, if you are taking blood-thinning drugs.
How does the examination take place?
The examination is generally performed using computerised tomography (CT). For this purpose, you will be
asked to lie on your front on the CT table. The radiologist then establishes which access route is best suited to
reach the diseased process. When the appropriate point has been found, the skin is initially numbed. The
needle is then pushed in slowly using imaging guidance, until it is located in the vicinity of the diseased process.
Then a small amount of x-ray dye is injected, in order to record the correct needle position and drug distribution
expected.
Wirbelkörper
Then local anaesthetic (= numbing drug) and a small amount (1ml) of cortisone derivative (Kenacort®) are
injected in addition. The latter is used for suppressing inflammatory reactions and is a direct analgesic. The
cortisone derivative is available as crystals and is manufactured in such a way that it releases its effect in the
injected area over several weeks.
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Possible side effects/behaviour after puncture
Side effects are very seldom. Few patients have an allergic reaction to local anaesthesia. Spreading of the
cortisone derivative into the rest of the body occurs in very small amounts and has no effect on otherwise
healthy patients. Caution is advisable with patients who undergo long-lasting cortisone treatment.
Some people tend to experience a so-called vasovagal reaction (sudden dizziness or fainting) to a nerve-root
block. Hence you should only get up / stand up with the help of the radiology assistant. Since nerve-root
infiltration changes both the sensitivity of the nerve root, and also its ability to control muscles, it is possible that
you will temporarily experience a certain weakness in your feet or legs. This is not dangerous. Nevertheless,
take care when standing up again for the first time that you do not fall.
The drug can also spread a little outwards from the target area. This is not dangerous, but it can result in a more
pronounced weakness until the effect of the local anaesthesia has faded away.
With temporary problems, such as dizziness/fainting or weakness in the legs, you have the possibility of lying
down until the problems disappear. Before leaving the x-ray department, you will be asked to mark with a cross
on a [given] scale the decrease in the degree of intensity of your aches and pains.
After leaving the x-ray department
You should not drive a car for at least 4 hours after the injection.
If you have any additional questions, please contact the radiology assistant or our doctors at any time.
I confirm that I have noted the above information.
Zurich, _______________________
Mai 2008 / MHB\32\320
Signature: _______________________
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