Local anaesthesia

Key points

• Local anaesthesia is used to reduce pain from procedures and operations and to reduce pain from certain conditions such as haemorrhoids and teething.
• You usually stay awake when having a local anaesthetic, but it may also be used when you are sedated or asleep.
• Types of local anaesthesia include topical (applied to the skin or mouth, for example for teething pain), injections (for minor procedures), nerve blocks (by anaesthetists), and spinal (such as an epidural).
• Local anaesthesia is usually very safe and well tolerated. There can be some side-effects but these are rare. Serious risks are also very rare.

How does a local anaesthetic work?

Local anaesthesia temporarily stops your nerves from sending pain signals. It takes a few minutes to take effect, then the area will become numb. You might feel some touch and pressure, but it shouldn’t be painful.

Are you awake during local anaesthesia?

Often minor procedures are done under local anaesthetic only, so you’ll be awake during the procedure. This is safer for you as it means you do not need a general anaesthetic, and will recover and be able to go home sooner.

When would I have a local anaesthetic?

You may have a local anaesthetic before you have:

• a needle put in your skin if you’re having an injection or a blood test
• a tube (called a cannula) put into a vein on the back of your hand before surgery
• dental treatment – for example, having a tooth taken out
• a minor procedure – this could be anything from a gastroscopy to having a skin lesion removed
• an eye operation - for example, having a cataract removed

You may also use a local anaesthetic to treat a painful condition such as:

• a sore throat
• haemorrhoids (piles)
• mouth ulcers
• sore nipples when you’re breastfeeding

Regional anaesthesia (a type of local anaesthesia) is done by anaesthetists, sometimes in combination with general anaesthesia or sedation. It will numb a particular nerve that supplies the area of your surgery to reduce pain. Spinal, or epidural local anaesthetic blocks are done by anaesthetists for operations below the tummy button, and are effective at reducing pain for pelvic and leg operations. They are very safe, and are often combined with sedation, or occasionally general anaesthesia. They are also used in childbirth where they have been shown to be safe and effective.

Sometimes, you may have a combination of different types of anaesthesia. For example, you may have an operation under general anaesthesia, then a local or regional anaesthetic to ease pain afterwards.

Types of local anaesthesia

There are three main types of local anaesthesia:

• topical anaesthesia
• local anaesthetic injections
• regional anaesthesia

Topical anaesthesia

This is when you have a local anaesthetic put on your skin. It may be in the form of a gel or cream, drops, an ointment or a spray. It may be used to numb the area before you have an injection or implant, so you don’t feel pain from the needle.

Local anaesthetic injections

A local anaesthetic can be injected just under your skin to target the nerves that make you feel pain. Your skin and the area just below it will feel numb afterwards. You may have this before a minor surgical procedure.

Regional anaesthesia

For regional anaesthesia, your doctor or anaesthetist will inject a local anaesthetic near a nerve. This is to numb a large area or an area deep inside your body. There are three types of regional anaesthesia.

Spinal anaesthetic

This involves a carefully placed injection of local anaesthetic into your lower back near the spinal nerves. This may be used before some types of pelvic or leg surgery – for example, a hip replacement.

Epidural anaesthetic

An epidural anaesthetic involves placing a small tube into the lower back near the spinal nerves. Local anaesthetic can then be put in to numb the nerves to your pelvis and legs. The anaesthetic can be topped up for up to 3 days to ease any pain. Epidural is commonly used for providing pain relief during childbirth.

It can also be used for surgery and pain relief. Epidural injections for neck, lower back and leg pain are also done by specially trained doctors using local anaesthetics and steroids. X-ray or ultrasound may be used to guide injection into the correct place..

Nerve block

If you have a nerve block, the local anaesthetic is injected into the tissues around a particular nerve. An ultrasound machine may be used to guide the injection to the correct place. This blocks the sensation to an area such as your hand, leg or head before you have a surgical procedure.

How quickly will I recover from a local anaesthetic?

After local anaesthesia, you may be able to go home on the same day. For nerve blocks, this might be several hours after the operation. If you have spinal anaesthesia, you may be able to go home the same day if it has completely worn off. Spinal injections for trapped nerves are usually done under local anaesthetic so you can go home the same day.

If you have a sedative, you may need to stay in hospital longer but will usually be able to go home on the same day. Epidural anaesthesia for surgery usually requires staying overnight as they can last longer.

How quickly you recover will depend on which type of anaesthetic you had. If you have regional anaesthesia, it will take some hours before you get your feeling back. The effects of nerve blocks can last up to 48 hours.

It’s important to protect the area while you’re still feeling numb, so you don’t hurt yourself. As your feeling returns, you may notice a tingling sensation. Your doctor may recommend you take painkillers as the local anaesthetic wears off. Ask your anaesthetist or nurse about when you’ll be able to eat and drink afterwards.

Driving after local anaesthesia

Ask your doctor about when it will be safe for you to drive. If you had sedation, you will need to wait at least 24 hours before you drive, and you must feel fit and ready to drive. You’ll also need to check your car insurance policy to check if you’re insured to drive after surgery.

What are the side-effects of local anaesthesia?

Local anaesthetic side-effects are usually mild and settle quickly.

You may have some discomfort when the local anaesthetic is injected into your skin. The area will feel numb until the anaesthetic wears off. Other side effects include:

• some redness or bruising around the skin where you were given the local anaesthetic – this is usually normal
• feeling faint with injections – tell your healthcare team if this has happened before, so they can prepare and support you
• infection or bleeding at the injection site – these are very rare

With some types of local anaesthetic, you may also get:

• a headache (if you have spinal or epidural anaesthesia)
• temporary problems with balance, leg strength or bladder control (if you have spinal anaesthesia) – you may need a catheter to drain urine away

Rare but serious complications include:

• a severe allergic reaction – tell your doctor if you have had a reaction to anaesthetic before
• local anaesthetic toxicity (too much anaesthetic in your bloodstream) – this is very rare, and your doctor will keep the dose below the level that causes this
• nerve damage – this is very rare, causing numbness and weakness. This can be temporary, lasting for a few days or weeks. Permanent nerve damage is very rare, this only happens in about 2 to 5 in 10,000 cases of peripheral nerve blocks. In spinal or epidural, it’s even rarer, only occurring in 1 in 20,000 cases. Serious damage to the spine only occurs in 2 out of 500,000 cases.

Your team will treat you if you have complications. Ask your anaesthetist for more information about the risks of anaesthesia.

What are the alternatives to local anaesthesia?

You may have general anaesthesia instead. This is when you're asleep during the operation. Having general anaesthesia isn’t as safe as local anaesthesia and you may take longer to recover afterwards. But you may prefer to be unconscious during your procedure. You can discuss your options with your anaesthetist or surgeon.

If you are scared of needles, you can request to have general anaesthesia and your doctor can discuss this with you. If you don’t want to stay awake for a procedure but are having a local anaesthetic, you may be able to have a sedative. This means you’re in a sleep-like state but won’t be unconscious.

After surgery, you may be able to have other painkiller medicines, such as morphine. You may have morphine into a vein through an intravenous drip which you can control yourself. This is called patient-controlled analgesia (PCA).