Epidural anaesthesia is usually a safe and reliable method of providing pain relief. However, as with most medical procedures, complications can sometimes occur.
Severe headaches
Following surgery, minor headaches are common. Occasionally, a more severe headache can develop after having an epidural. This is sometimes known as a post-dural puncture headache.
Post-dural puncture headaches are thought to be caused if the lining of the fluid-filled space that surrounds your spinal cord (dura) is accidentally punctured as the local anesthetic is injected into the epidural space.
During an epidural, local anaesthetic is injected just outside the dura. However, if the needle punctures the dura, the fluid inside will leak out, resulting in a fall in the pressure of the fluid that surrounds your brain and spinal cord. The decrease in pressure can lead to a persistent headache.
A procedure known as a ‘blood patch’ can be used to seal up the hole. It involves taking a small sample of your own blood and injecting it into the epidural space. When the blood clots (thickens), the hole will be sealed and your headache will stop.
It should be noted that headaches that are caused by a punctured dura are uncommon following an epidural. There is just a 1 in 100 to 1 in 500 chance of it happening.
Infection
Infections are also a rare complication of an epidural, occurring in about 1 in 47,000 cases.
However, it is possible for an infection to develop at the site of the injection in the weeks following an epidural. This can lead to serious complications, such as the formation of an abscess (a painful collection of pus).
Measures will be taken before the epidural is given to prevent an infection developing at the injection site. These include:
- using a sterile solution to clean the area of skin before the injection is given
- using a sterile needle and catheter (thin tube) when carrying out the epidural
It is very rare for an infection to spread beyond the injection site.
Epidural haematoma
An epidural haematoma is a very rare complication of epidural anaesthesia, occurring in around 1 in 120,000 cases.
A haematoma is a collection of blood (a blood clot) that builds up in an organ, a tissue or space. It occurs as a result of a break in a blood vessel wall.
The epidural space is filled with a number of veins. If the veins are punctured, blood can build up within the epidural space. A build-up of blood can result in the formation of a haematoma, which can place pressure on your spinal cord.
This can lead to serious complications, such as paraplegia (complete loss of movement of the lower half of the body, including your legs). However, this further complication is also very rare.
Other complications
Other possible, although rare, complications of an epidural include the following:
- fits (convulsions)
- breathing difficulties
- nerve damage
Before deciding to have an epidural, you should discuss the procedure with your anaesthetist (a doctor who is specially trained to provide pain relief during surgical procedures). They will be able to provide further information and advice about the risks of developing complications such as those described above.
