Epidural anaesthesia, often referred to as 'an epidural', is an injection in the lower back that numbs the nerves and stops you feeling pain.
Areas that can be numbed by an epidural include the:
- chest (thoracic area)
- pelvic area
How an epidural works
During an epidural, an anaesthetist uses a needle to locate an area of the spine known as the ‘epidural space’. An anaesthetist is a doctor specially trained to provide pain relief during surgical procedures.
The anaesthetic works by numbing pain nerves as they enter the spine. The extent of the numbness will depend on the type of drug used, and the amount injected. Once the medication has worn off, feeling in the affected areas will return.
Read more about how an epidural is performed.
When is an epidural used?
An epidural can be used to provide pain relief in a number of different situations including:
- during natural childbirth
- during an operation, instead of a general anaesthetic
- after surgery that has been carried out under general anaesthetic (where you are unconscious during the operation)
Read more about why an epidural is used.
This topic focuses mainly on having an epidural during labour and childbirth.
Epidurals have been routinely used for many years and are widely accepted as an effective method of providing pain relief after surgery, and during labour and childbirth.
However, as with many medical procedures, there are some associated risks that, although small, you should be aware of before deciding whether to have an epidural. Two possible risks include:
- puncture of the dura - the dura is the thickest, outermost layer that surrounds the spinal cord and brain; the risk of the dura being punctured is about 1 in 100
- nerve damage - which can very rarely occur
Read more about the complications of an epidural.
Although epidurals are commonly used to provide pain relief, they are not always effective at reducing labour pain. The Obstetric Anaesthetists Association estimate that 1 in 8 women who have an epidural during labour need to use other methods of pain relief.
Read more about the side effects of an epidural.
What it is used for
An epidural is a type of local anaesthetic. It can be used to completely block pain while you are awake.
This has the advantage of allowing you to avoid the common side effects of general anaesthetic, such as feeling sick and dizzy. In addition, you will avoid the rare, but serious, complications of a general anaesthetic.
Epidural anaesthesia can be used to numb sensation and provide pain relief in a number of situations including:
- during natural childbirth
- during a Caesarean section, where a baby is delivered through a cut that is made in the abdomen
- after surgery that has been carried out under general anaesthetic
- during other types of surgery, such as knee surgery, hip replacement surgery, rib or chest fractures and amputation of the lower limbs
Epidurals are most commonly associated with being used to reduce pain and discomfort during labour and childbirth. This topic focuses mainly on this use of epidural anaesthesia.
Labour and childbirth
Some women decide to have an epidural during labour and childbirth. Your midwife will be able to advise you about having an epidural and whether they think it is necessary. However, remember that the final decision will be yours.
An epidural may be recommended to help relieve pain during:
- a particularly painful, complicated or prolonged labour
- the delivery of twins or triplets
- a Caesarean section delivery if an epidural was sited during labour
- an assisted delivery – where either forceps or a suction cap (Ventouse) is attached to the baby's head to help with the delivery
Read more about [pain relief during labour].
Mobile epidurals, also known as walking epidurals, are low-dose epidurals that may be used during labour. A smaller amount of local anaesthetic is used in combination with other painkilling medication.
As your nerve sensations will not be completely blocked, a mobile epidural provides pain relief without as much of the numbness or heavy-legged feeling that is experienced during a full epidural.
Another advantage of having a walking epidural is that you will be able to feel the contractions and the need to push during the final stages of labour.
As you will still have some sensation in your legs, you will also be able to move around if you need to, although it is not always recommended.
Why epidurals might not be used
In rare cases, an epidural is not recommended. For example, it may not be suitable if you:
- are allergic to local anaesthetics
- you are taking medication to thin your blood, such as warfarin
- have a blood-clotting abnormality that increases your risk of bleeding
- have previously had back surgery, or you have other problems with your back
- have a spinal deformity or severe arthritis in your spine
- have a neurological condition that affects your nervous system, such as spina bifida
Your anaesthetist will be able to provide you with more information and discuss the potential risks in these situations.
There are several potential side effects that can occur after having epidural anaesthesia.
Low blood pressure
Low blood pressure (hypotension) is the most common side effect associated with having an epidural. This is because the local anaesthetic used affects the nerves that go to your blood vessels, leading to a fall in blood pressure. This may cause lightheadedness or nausea.
Your blood pressure will be closely monitored while you are having an epidural. If necessary, medication can be passed through a drip to treat low blood pressure.
Pain and discomfort
You may experience some slight discomfort when local anaesthetic is injected to numb the skin during epidural insertion. However, you should not feel pain when drugs are injected into the epidural space.
Sometimes, it is also possible for an epidural to be unsuccessful. For example, this might occur if:
- it proves difficult to find the epidural space
- the local anaesthetic does not spread evenly around the epidural space
- the catheter falls out
If your epidural fails to work, your anaesthetist will see you and attempt to improve the numbness. If the epidural cannot be improved, they will offer alternative pain relief, which may include performing the procedure again.
Loss of bladder control
After having an epidural, you will not be able to feel when your bladder is full. This is because the epidural affects the nerves around your bladder.
A catheter will be inserted into your bladder to allow urine to drain away. Your bladder control will return to normal as soon as the epidural wears off.
Sometimes, the painkillers that are combined with local anaesthetic during an epidural can cause itchiness. If you develop itchy skin it can usually be treated.
You may feel sick (or actually be sick) after having an epidural. However, you are more likely to experience this side effect with a general anaesthetic. If your blood pressure is normal, anti-sickness medicines will usually help.
A study carried out in 2010 found no increased risk associated with the use of epidural anaesthesia and long-term backache.
Your epidural care team will try to ensure you are comfortable during and after the procedure, but being in the same position for a prolonged period may inevitably make existing backache worse.
If you experience severe backache in the weeks following an epidural, you should report your symptoms to your care team as soon as possible so they can investigate the problem.
Epidural anaesthesia is usually a safe and reliable method of providing pain relief. However, as with most medical procedures, complications can sometimes occur.
Following surgery, minor headaches are common. Occasionally, a more severe headache can develop after an epidural, known as a post-dural puncture headache.
Post-dural puncture headaches are caused when the lining of your spinal cord (dura) is accidentally punctured. This can occur during insertion of the epidural.
If the epidural needle punctures the dura, the fluid inside will leak out, resulting in a fall in the pressure of your brain and spinal cord. The decrease in pressure can lead to a persistent headache.
Although the headache symptoms may resolve with time, 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 caused by a punctured dura are uncommon following an epidural. There is a 1 in 100 to 1 in 500 chance of it happening.
Infections are a rare complication of an epidural.
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 an abscess (a painful collection of pus) forming.
It is rare for an infection to spread beyond the injection site.
An epidural haematoma is a very rare complication of an epidural.
A haematoma is a collection of blood that builds up in an organ, a tissue or space. It develops 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, causing pressure on your spinal cord.
This may lead to severe nerve damage, 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 possible, although rare, complications of an epidural include the following:
- fits (convulsions)
- breathing difficulties
- nerve damage leading to a numb patch of skin
- other causes of nerve damage
However, serious complications following an epidural are rare. The best estimate of the overall risk of permanent harm from an epidural in labour is between 1 in 80,000 and 1 in 320,000.
Before deciding to have an epidural, you should discuss the procedure with your anaesthetist. They will be able to provide further information and advice about the risks of developing complications such as those described above.
How it is performed
If you choose to have an epidural, the procedure will be carried out by an anaesthetist. An anaesthetist is a doctor, specially trained in providing patients with pain relief during medical procedures.
Having an epidural
Most epidurals are given while the patient is sitting down and leaning forwards. Alternatively, an epidural can be carried out while you are lying on your side with your knees drawn up and your chin tucked in.
Lying or sitting in these positions opens up the spaces between the bones of your spine (vertebrae) and allows the epidural needle to be passed into the epidural space more easily. This is an area through which the nerves from your spine to your body pass.
Before the epidural needle is inserted, a sterilising solution is rubbed into your back and sterile drapes are placed over your back, leaving the injection site exposed.
An injection of local anaesthetic into the skin helps to reduce any discomfort. A hollow needle is then inserted and a thin, plastic tube (epidural catheter) is passed through the middle of the needle, into the epidural space. The epidural anaesthetic can then be injected through the tube.
If you are having an epidural during childbirth, you will need to have a drip in your hand so that fluid and medication can be given to help prevent low blood pressure, a common side effect of epidurals. The drip may restrict you from moving around freely.
While you are having an epidural inserted, you may experience a brief stinging sensation as local anaesthetic is injected into the skin. You may also experience slight discomfort in your back when the epidural needle is positioned, and the catheter is inserted.
If you feel pain or an electric shock-like feeling, tell your anaesthetist, because the catheter may be pressing against the root of a nerve and may need to be repositioned.
Effects of an epidural
Shortly after having an epidural you will start to experience a warm, numbing sensation in your lower back and legs. Your legs may feel heavy and more difficult to move. It usually takes about 20-30 minutes for the epidural to take full effect.
The nerves in your bladder are also likely to be affected by the anaesthetic. This means you won't know when your bladder is full, and whether you need to go to the toilet. To prevent damage, a thin plastic tube (catheter) will be used to drain urine from your bladder. Your bladder sensation will return to normal when the epidural is stopped.
Read more about the side effects of an epidural.
After having an epidural
Following epidural anaesthesia, it is likely you will be advised to rest in a lying or a sitting position until the feeling in your legs returns.
It usually takes a couple of hours for the feeling to return to your legs and you may experience a slight tingling sensation on your skin as the anaesthetic starts to wear off. You may need help getting out of bed.
If you start to feel any pain, you should tell the doctor or nurse who is treating you. They will be able to give you medication to help control it.
After having an epidural you will be able to breastfeed your baby.