What is an epidural steroid injection?
An epidural steroid injection involves injecting a steroid into the epidural space. This is a space that surrounds the spinal cord. Local anaesthetic (or even a solution called normal saline) with the steroid will bathe the nerve roots which send pain signals to the brain. Epidural injections can be given anywhere along the length of the spine. This may be in the neck (cervical), between the shoulder blades/back of chest (thoracic), lower back (lumbar) or tailbone (caudal).
Epidurals are used mainly for radicular pain (sciatic leg or arm pain) pain where simpler measures have not helped. It may help your pain by reducing some of the pain signals. Pain relief can be short-lived though some people can get significant and lasting pain relief from these injections, it may not be a cure. The injection is usually undertaken alongside other treatments such as physiotherapy.
What will happen to me during the treatment?
Before the injection, your doctor will discuss the procedure with you. Your doctor will either obtain your consent before the injection or confirm this consent if it was previously given. The treatment will take place in a dedicated area with trained personnel. An X-ray machine (or other forms of image guidance) will often be used to enable accurate injection. Not all doctors undertake these injections in exactly the same way but the following usually happens:
- You will be prepared for the procedure as per local protocol
- Observations such as blood pressure and pulse rate may be made
- A small needle (cannula) will be placed in the back of your hand – if the injection is at the neck
- You will be carefully positioned and the skin around the injection site(s) will be cleaned with an antiseptic solution or spray; this can feel very cold
- You will feel a stinging sensation as local anaesthetic is injected to numb the skin and surrounding tissues. Your doctor will warn you of this first
- The needle is guided to the epidural space using a technique known as “loss of resistance” where there is a decrease in pressure in a syringe attached to the needle or ‘hanging drop’ technique when performed at the neck. X-ray might be used to confirm correct placement
- The doctor will direct the injection to the epidural space close to the source of pain and usually inject contrast (a solution that is visible under imaging such as X-ray) to ensure the needle is correctly positioned. When the injections are made, you may feel pressure, tightness or a pushing sensation in your back or leg. If there is any discomfort, let the doctor know.
What will happen to me after the injections?
You may be assisted to sit up and your blood pressure and pulse may be checked. You will be advised when to get dressed and be given assistance to help to ensure that you can stand safely after the procedure.
When will I be able to go home from hospital after my injections?
You will usually be able to return home soon after the injection. Please ensure that you have made arrangements for someone to collect you after the procedure. It is unsafe for you to drive home immediately after the procedure. If you do so your motor insurance will be invalid.
What can I do after my procedure?
Ideally, you should arrange for someone to stay with you for 24 hours but, failing that, you should at least have access to a telephone.
When can I return to work after the procedure?
This will vary between individuals and may depend on the nature of your work. It is difficult to give general advice and so you should discuss this with your doctor.
Will I experience any side effects?
As with any procedure, side effects may occur. These are usually minor but there are risks with this procedure.
Side-effects may include:
- Mild local tenderness and/or bruising at the site of the injection. This usually settles over the first few days.
- The local anaesthetic may rarely spread causing some numbness and/or weakness in your legs (lumbar injections) or arm (cervical injections). Should this occur, the effect is temporary and will rapidly resolve over minutes or rarely hours.
- Infection. This is rare. You should seek medical help if there is local warmth or redness over the site of injection with tenderness and/or you feel hot and unwell. This may require antibiotic treatment.
- There are very important nerves in the spine, but serious nerve injury is extremely rare (less than 1 in 10,000 cases) and can occur when there is serious bleeding or infection abscess near the spinal cord, or even physical injury from the needle or injection itself. This is why the doctor takes such great care in performing the injection. Persistent weakness of the legs and/or incontinence require further urgent investigation. These injections have very rarely caused severe harm. Please speak to your doctor to discuss this issue fully.
- Blood pressure may temporarily fall and rarely, people may occasionally feel faint.
- Headache. On rare occasions the epidural needle may be placed too far and spinal fluid (CSF) encountered. This is called a dural puncture and may lead to headache that requires further treatment. If a severe headache does develop following your injection, take some paracetamol, drink plenty of water and lie flat. If the headache continues for more than twenty-four hours please contact your GP or pain clinic.
- Injection treatments are not always effective and may not help your pain.
What can I expect in the days afterwards?
You may experience some soreness or aching at the injection site. Do not worry if your pain feels worse for a few days as this sometimes happens. Take your regular pain killers and medications as normal and this should settle down. Try to keep on the move about the house whilst avoiding anything too strenuous.
What should I do in the weeks after the injections?
As your pain decreases, you should try to gently increase your exercise. Simple activities like a daily walk, using an exercise bike or swimming on your back will help to improve your muscle tone. It is best to increase your activities slowly. Try not to overdo things on a good day so that you end up paying for it with more pain the following day.
What follow-up will be arranged?
A letter will be sent to your GP and your doctor will advise on what to do after the procedure. You will be also sent a letter with a review appointment.
Is there anything else I need to consider before the procedure?
- Please bring your glasses if you need them for reading.
- Always bring a list of all current medication.
- Continue to take your medication as usual on the treatment day.