Epidurals for surgery and pain relief

An epidural is an injection of medicines into your back. It stops you from feeling pain in the lower half of your body. Epidurals are used during surgery, often with a general anaesthetic. An epidural can also be used for pain control during and after an operation or procedure.

This topic covers epidural injections that you may have during, and sometimes after, an operation. We have separate information about epidural injections for lower back and leg pain.

Uses of an epidural

Your anaesthetist may recommend you have an epidural for several reasons.

• Having an epidural might mean you don’t have to have a general anaesthetic.
• If you have a general anaesthetic with an epidural, you may need less of the general anaesthetic medicine. This may help your recovery afterwards by reducing the chance of some complications.
• If the epidural continues after your operation, you’re less likely to need other strong painkillers. This means you’ll be less likely to feel sick, you’ll be more alert, and your breathing will be better.
• An epidural may reduce the amount of blood you lose during your operation, compared to having a general anaesthetic.
• You may be less likely to have a deep vein thrombosis (DVT), compared to having a general anaesthetic.
• If your anaesthetist offers you an epidural, it’s your choice whether or not to have one. Ask them to explain what the possible benefits and risks are for you.

An epidural isn’t suitable for everyone. If you’ve had an operation on your back before or have a blood clotting problem, it might not be the best option. Tell your anaesthetist if you’re taking any blood-thinning medicines such as warfarin.

The epidural procedure

Your anaesthetist will explain what they’re going to do, and what you might expect to feel. They’ll start by using a needle to put a fine plastic tube (a drip) into a vein in your hand or arm. This lets them give you fluid if you need it during your operation.

They’ll ask you to lie on your side or sit up. You’ll need to bend forwards or curl up so that your back is as curved as it can be. The anaesthetist will clean the skin on your back using an antiseptic. Then you’ll have a small injection of local anaesthetic to numb the skin.

Once your skin is numb, your anaesthetist will put a larger needle into the epidural space in your back. When the needle reaches the right spot, they’ll put a thin flexible tube (catheter) through the needle. Your anaesthetist will then remove the needle, leaving the catheter behind. They’ll use some tape to hold the catheter in place.

It's really important to stay still when your anaesthetist is putting the epidural needle in. Let them know if it hurts or if you feel any tingling sensations. This will help your anaesthetist to give you the epidural safely.

Your anaesthetist will inject local anaesthetic and/or other pain-relieving medicines through the catheter. They might attach the catheter to an infusion pump to give the medicines continuously. Or you might have another dose of medicines given through the catheter after your operation.

Your anaesthetist will use an icy-cold spray, or prick your skin with a pin to check that you’re body is numb before your surgeon starts your surgery.

During the operation you might feel a sensation of pushing or pulling. Since you’ll be awake, you may hear the medical staff moving around and talking or the equipment making noises. You won’t be alone – your anaesthetist will be there if you want to speak to them.

A cloth screen is usually put up to hide the area being operated on. You won't see what your surgeon is doing unless you want to.

When you don’t need pain relief anymore, your anaesthetist will take out the catheter. An epidural catheter would normally only stay in place for a few days at most.

Aftercare following an epidural

After an epidural, you’ll need to rest until the effects of the anaesthetic have worn off. Your legs may be a bit unsteady for a while.

The feeling and movement should return to normal within anything from one to 18 hours after the last dose of medicine through the epidural catheter. It will depend on the type of medicine you have in the epudural. Tell your nurse if you’re in any pain.

If you have a pump connected to your epidural catheter, your nurse will check this regularly to make sure it’s working properly.

`If you have backache after your operation this might be caused by lying on the flat operating table. But if it gets worse, contact your surgeon or the hospital. You should also contact them if you start to feel weak, numb, or have any problems with your bladder or bowels.

Don’t drive, operate machinery or drink alcohol for 24 hours after having an epidural.

Side-effects of an epidural

Side-effects are the unwanted, but mostly temporary effects of a successful procedure. Common side-effects of an epidural include the following.

• Not being able to pee. This can happen if the nerves to your bladder are affected by the epidural. You might need to have a catheter into your bladder until the effects of the epidural wear off. This is a thin tube that drains pee (urine) from your bladder into a bag outside your body.
• Feeling sick and being sick. This is less likely to happen after an epidural than after a general anaesthetic.
• A drop in your blood pressure. Your anaesthetist or specialist nurse will check your blood pressure regularly. If it drops, you might be given fluids and medicines to bring it back up.
• Losing strength or control of your muscles. Your legs might feel heavy and hard to move. This should wear off once the epidural is stopped.
• Pain. Sometimes the epidural doesn't work as well as expected. You might need to have a top-up dose or use another type of painkiller. Or your anaesthetist may need to give you an epidural in a slightly different location in your back.
• Itchy skin. This can be treated with medicines if you need them.

Complications of an epidural

All medical procedures, no matter how safe, carry some risk of complications. This is when problems occur during or after the procedure. Possible complications of an epidural include the following.

• A headache. The epidural injection can make a hole in the bag of fluid around your spinal cord. The fluid inside can then leak out. This means there’s less fluid around your brain, which is what gives you headaches. They can feel like a bad migraine and get worse when you’re sitting or standing. The headache often gets better if you lie flat, drink plenty of fluid and take painkillers. If that doesn’t work, your anaesthetist may inject a small amount of your own blood into your back. The blood clot seals the hole.
• An infection. This is rare, but if you get an infection, you’ll probably need to have antibiotics.
• Bleeding. Very rarely, blood clots can form in the epidural space This can cause a permanent injury if it’s not noticed. You’ll be monitored closely to prevent this from happening.
• Nerve damage. This can range from numbness and pins and needles through to being unable to move or have control over your bladder and bowels. In most people, this gets better after a few days, weeks, or months. Rarely, it can be permanent.
• Difficulty breathing. Some medicines used in epidurals can make your breathing slow or make you drowsy. You’ll have treatment if this happens.

Alternatives to having an epidural

Epidurals aren’t suitable for everyone. Alternatives to having epidural anaesthesia for surgery include the following.

• Spinal anaesthesia. This is when a local anaesthetic is injected directly into the fluid around the spinal nerves in your lower back.
• General anaesthesia. This is when you're asleep during the operation.
• A nerve block. This is an injection of local anaesthetic given near a nerve or group of nerves. Nerve blocks can be used as pain relief both during and after an operation.

You can also have a strong painkilling medicine such as morphine after an operation. Your anaesthetist can give you morphine as a tablet or liquid to swallow, or as an injection. You may be able to have morphine given through an intravenous drip which you control. This is called patient-controlled analgesia (PCA).

Ask your anaesthetist to talk to you about your options for pain relief.