What is an epidural injection?

A common cause of sciatic pain is an inflammatory response to nerve irritation by a disc protrusion or nerve entrapment. An injection of steroids (anti-inflammatory medication) into the epidural space can act to decrease this inflammation, thus decreasing pain.

Patient preparation

You will need to fast for two hours prior to the procedure.

Please inform us if you take any blood- thinning medication (i.e. Aspirin, Warfarin, Clopidogrel etc) or if you have any allergies.

What will happen during the examination?

You may be asked to change into a gown and to lie face down on the CT examination table. Your skin will be cleansed around the area of interest to create sterile conditions.. CT imaging is used to accurately locate the area to be injected and to guide the needle. It is important you keep as still as possible during the procedure.

A radiologist (specialist medical imaging doctor) will then use CT imaging to guide the needle into position into the epidural space and inject the steroid and local anaesthetic solution. The needle is removed and a sterile dressing applied. .

Are there any risks?

You will receive a small dose of x-ray radiation. Please advise the radiographer if you are, or think you may be pregnant.

Bleeding, though rare, can occur into the epidural space, causing pressure.

Infection into the epidural space, which is rare, can also occur.

If the fluid sac around the nerves is punctured, this can lead to a fluid leak that results in a headache. This usually settles over a few days with bed rest and analgesia. Only rarely does this require further treatment.

Spinal cord injury with transient or permanent paralysis is very rare.

After the examination

You may experience some soreness or bruising at the needle site and rarely, minor muscle spasm. Occasionally referred pain can increase in the days after procedure.

Once you are feeling comfortable you may leave. We recommend you have someone to drive you home after the procedure. Please consider this when making your appointment. We request you do not perform any lifting or physical activities that may aggravate your condition for at least 12 hours after the procedure.

Effects from the treatment

The local anaesthetic may provide temporary pain relief for up to four hours. Paracetamol may be taken if you experience discomfort. The steroid can take up to a week to reach maximum effect. Relief from symptoms does vary between patients, both in time and scale.

Some people do not receive pain relief from the procedure if the nerve root is not the cause for their pain. This is generally not a failure of the procedure. This information is useful for your doctor and indicates other causes of pain may need to be considered.