What is an Epidural?

The nerves from your spine to your lower body pass through an area in your back close to your spine, called the 'epidural space'.

An epidural catheter (a fine plastic tube) is inserted by an anaesthetist into the epidural space. Local anaesthetic is then injected through the epidural catheter into this epidural space. As a result, the pain messages are blocked. This causes numbness, that varies in extent depending on the amount and strength of the local anaesthetic injected. An epidural pump allows local anaesthetic to be given continuously.

Other drugs to manage pain can sometimes be added to the local anaesthetic in small quantities. The amounts of drugs given are carefully controlled. When the epidural is stopped, full feeling will return, although this may take a few hours. Epidurals may be used during and/or after surgery for pain management.

How is an epidural put in?

An epidural can be put in when you are awake or under a general anaesthetic. The anaesthetist can also give you a drug to make you relaxed (sedation)

A needle will be used to put a thin plastic tube (a 'cannula') into a vein in your hand or arm for giving fluids (a 'drip'). If you are conscious, you will be asked to sit up or lie on your side, bending forwards to curve your back. It is important to keep still whilst the epidural is put in. If you move the risk of complications can increase

Local anaesthetic is injected into a small area of the skin of your back; this may sting a little. A special epidural needle is pushed through this numb area and a thin plastic catheter is passed through the needle into your epidural space. The needle is then removed, leaving only the plastic epidural catheter in your back.

What will I feel?

The local anaesthetic stings briefly, but usually allows an almost painless procedure.

It is common to feel discomfort in your back, or tingling in your legs as the needle or catheter is inserted. Occasionally, an electric shock-like sensation or pain occurs during needle or catheter insertion. If this happens, you must keep still and tell the anaesthetist immediately.

A sensation of warmth and numbness gradually develops, like the sensation after a dentist gives you an injection into your gums. You may still be able to feel touch, pressure, heat, cold and movement but you should not feel pain. The area of numbness that occurs will depend upon the site of your operation. You may only notice these effects for the first time when you wake up after the operation, particularly if your epidural was put in when you were asleep.

Overall, most people do not find these sensations to be unpleasant, just a bit strange.

What are the benefits?

Good pain management, particularly when you move.

Reduced complications of major surgery, e.g. sickness/vomiting, leg/lung blood clots, chest infections, blood transfusions, slowed bowel function.

Less sedation, quicker return to eating, drinking and full movement, possibly with a shorter stay in hospital compared to other methods of pain relief.

When will an epidural be stopped?

The epidural will be stopped when you no longer require it for pain relief, generally when you are drinking and able to take painkillers as tablets.

The epidural will be stopped if it is not working properly. Another epidural catheter can be placed if necessary or another method of pain management started.

Once your epidural has been stopped it can be restarted if you feel unable to cope without it.

A few hours after the pump is stopped, the epidural catheter will be removed, as long as you are still comfortable.

Can anyone have an epidural?

No. An epidural is not always possible if the risk of complications is too high. The anaesthetist needs to know if:

• you are taking blood thinning drugs, such as aspirin or warfarin
• you have an abnormality of blood clotting
• you have an allergy to local anaesthetics
• you have severe arthritis or a severe deformity of the spine
• you have an infection in your back or anywhere else in your body

Side effects and complications

Common:

• Inability to pass urine

The epidural affects the nerves that supply the bladder, so a catheter ('tube') will usually have to be inserted to drain your bladder. This is often necessary anyway after major surgery to check that your kidneys are working normally. Bladder function returns to normal when the epidural wears off.

• Low blood pressure

The local anaesthetic affects the nerves going to yourblood vessels, so your blood pressure will drop a little when an epidural is in use. Fluid and/or drugs can be put into your drip to treat this. Low blood pressure is common after surgery, even without an epidural.

• Itching

This can occur as a side effect of morphine-like drugs used in combination with local anaesthetic. It can usually be easily and successfully treated.

• Feeling sick and vomiting

These symptoms can be treated with anti-sickness drugs. These problems are less frequent with an epidural than with many other methods of pain relief.

• Backache

Patients with a history of back problems are not at incresed risk of backache after an epidural for surgical pain management. This is common after surgery, with or without an epidural. It is often caused by lying on a firm operating table.

• Inadequate pain relief

Epidurals usually provide better pain management than other techniques. Other methods of pain management can be used if the epidural fails to provide adequate pain relief, or if it is not possible to place the epidural catheter.

• Headaches

Minor headaches are common after surgery, with or without an epidural. Occasionally a severe headache occurs after the insertion of an epidural. This is because the lining of the fluid filled space surrounding the spinal cord has been inadvertently punctured (a 'dural tap'). Although simple pain relief may be enough to control this, sometimes another procedure (a 'blood patch') is necessary.

Uncommon:

• Slow breathing

Some of the drugs used in the epidural can cause slow breathing and/or drowsiness that require treatment.

• Catheter infection

The epidural catheter can become infected, if this happens it will be removed. Antibiotics may be necessary. It is very rare for the infection to spread any further than the epidural insertion site in the skin.

Rare or very rare complications:

Other complications can occur, such as convulsions (fits), breathing diffificulty and temporary nerve damage are rare. Permanent disabling nerve damage, serious epidural infection, epidural haematoma (blood clot) and cardiac arrest (stopping of the heart) are very rare indeed.

In comparison, you are more likely to die from an accident on the roads or in your own home than suffer permanent damage from an epidural. You will be monitored closely for any complications or side effects. These risks can be discussed in more detail with your anaesthetist.

Further information

Ask the nursing staff or your anaesthetist.

Information about epidural anaesthesia available from the website: www.youranaesthetic.info

In Leeds Teaching Hospitals there is a team of nurse specialists and anaesthetists who specialise in pain management after surgery. You can ask to see a member of the pain team. They will be able to give you support and information on how to manage your pain.

You can download an expanded version of this page in an acrobat format:
EpiduralInfo.pdf