Pain specialists perform injections into muscles, joints, nerves and many structures all over the body. Most of the time we inject a combination of anti inflammatory medication (steroid), a local anaesthetic (temporary) or type of alcoholic (permanent) destructive agent. One of the commonest procedures we do is the epidural injection. It is similar to what anaesthetists do for pain relief in labour.
What is it ?
The epidural space is located around the outer covering of the spinal cord. It runs from the base of the skull to the bottom of the spine. Not only do nerve fibres carry pain signals through this space to the brain, but inflammation and arthritic changes can occur in and around other structures within the spinal canal area.
The local anaesthetics we inject temporarily block the function of the nerves while the steroids reduce inflammation and improve the chances of longer-term pain relief. These steroids should not be confused with ANABOLIC steroids that sportsmen use to build up muscles. Unfortunately no company to this day actually produces a steroid licensed specifically for the epidural space, but those preparations that we have been using since the early 1970s are considered to be very safe by national and international organisations.
Why an epidural?
We give epidurals for patients with back/leg pain or neck/arm/shoulder pain that is due to inflammation of the nerves, arthritis in the neck or back. Our aim is to reduce pain, improve mobility and facilitate physiotherapy.
How is it done?
The injection can be done with you sitting up, lying on your side or lying face down. An IV cannula may or may not be placed first at the back of your hand. The Doctor will select the area he wishes to inject and clean with an antiseptic. The Doctor is expected to talk you through as everything is going on behind your back, so to say. He may or may not use a special xray called fluoroscopy to guide his needle placement. This is more likely if you are lying face down for the procedure.
What are the benefits?
The goal is pain reduction. This may be evident from a reduction in medications, more mobility, better sleep, or better response tomphysiotherapy. The relief may take days or weeks to take effect and may not be 100% complete. In some patients, there may be no relief at all.“What are the side effects?
There are situations whereby we may reconsider the need for an epidural and also situations whereby we absolutely must not do an epidural. These must be discussed with your pain specialist. In addition, the side effects can be due to the actual injection, the local anaesthetic or the steroid. They can be mostly mild and self limiting but a few can be severe and require special treatment. They must be discussed with the pain specialist as part of your right of informed consent.
It is very important to let the Pain Clinic know at least a week in advance:
If you are allergic to any medications
If you are on blood thinning medications (like warfarin, aspirin, Plavix, ticlid, heparin)
If you have an infection
If you have an infection near the proposed site of injection
If you have had a recent steroid/cortisone injection
If you think you might be pregnant
If you are a diabetic on insulin
If you have had a recent heart attack or vaccination.
You should try to continue your normal activities or try to increase your activity and reduce your painkillers if the injection appears to be successful.
A follow/up appointment in would have been arranged by the Pain Clinic for the Doctor to review the effects of the injection.
Research evidence suggests that epidural steroid injections work well for back and leg pain especially if due to disc problems. If the scan of the spine shows more of narrowing than inflammation, the injections are not quite as effective.
Evidence also advices that the best results are obtained when the injections are repeated two to
three times, 2-3 weeks apart.
Relief, if successful, may last 4 to 12 months.