In what situations will I have a local anaesthetic?

An increasing number of operations and procedures are being offered under local anaesthetic. These procedures include minor operations, such as the stitching of wounds or mole removal to more complicated procedures (eye surgery including corneal transplant or cataract removal).

Local anaesthetics may also be used for a number of tests that may be uncomfortable to endure without pain relief, such as colonoscopy or when tissue samples are taken (biopsy).

Regional anaesthesia

If a larger (or deeper) area of the body needs to be numbed, regional anaesthesia may be used. This uses similar drugs to local anaesthesia, but acts on a wider area.

Regional anaesthetics also affect your muscles, so limbs can feel heavy and clumsy. Any movements that involve weight-bearing - such as walking or standing - may be restricted.

The most common regional anaesthetics (blocks) are:

Spinal anaesthesia

This is an injection of anaesthetic drugs into the fluid that lies between two vertebrae (or discs) in the lower back. The block removes all feeling from the waist down. Spinal anaesthesia takes a couple of minutes to work and lasts for around two hours

Epidural anaesthesia

This is similar to a spinal anaesthetic, but uses a cannula (a narrow plastic tube which is passed into a small space just around the spinal cord or epidural space and taped into place to stop it slipping) so that the anaesthetic can be 'topped up' as required. Epidurals are often used during surgery and childbirth and also as pain relief after an operation

Other regional anaesthetics:

Caudal anaesthesia

Similar to an epidural, but in this procedure the needle is placed at the bottom of the spine

When are regional anaesthetics used?

Spinal and epidural anaesthetics are often used for operations on the lower body, such as Caesarean sections, hip replacements or bladder operations.

Spinal anaesthetics are often used when a general anaesthetic is considered too risky (especially in older people).

Epidurals are a common pain relief option offered to women during childbirth.

Sedation

Sedation is used to make you physically and mentally relaxed, especially before a surgical procedure, which could cause discomfort or about which you feel anxious.

Sedatives can be light, so you can still talk and follow instructions, or a larger dose may make you drowsy so you fall asleep during the procedure. People who have had sedation may not have a clear memory of what has happened.

Sedation is often given in tandem with regional or local anaesthesia. Sedative drugs can be inhaled (etonox), swallowed or injected. While most of the effects wear off within six hours, it can be 24 hours before you are completely back to normal, so you will often have to be collected from hospital and definitely must not drive.

Who can administer a local anaesthetic?

A local anaesthetic will normally be administered by the doctor or surgeon doing the operation.

Regional anaesthetics are given by anaesthetists, who are doctors with specialist training in anaesthesia, as well as pain management and emergency care. If you have to have a regional anaesthetic, your anaesthetist will discuss it with you and tell you about any possible risks.

The anaesthetist will also make sure you are fully numb during the procedure and that when you come round afterwards you will be comfortable and pain free.

How are local and regional anaesthetics administered?

• Local anaesthetic drugs are administered by injection, by spraying liquid on to the skin, by using of drops, or by rubbing an anaesthetic cream into the skin. They work quickly, often within a few minutes, although the cream may need to be applied a couple of hours prior to the procedure. If the anaesthetic is injected, it can sting for a few seconds, but the skin will then lose feeling. No special preparations are needed prior to a local anaesthetic. You can eat and drink normally. Depending on what was done, you may be able to drive home afterwards. Local anaesthetics are not sedatives.
• Prior to being given a regional anaesthetic, you will have to follow special instructions about what you can or cannot eat and drink. For example, you may be asked not to eat or drink for a few hours before the anaesthetic is given. A local anaesthetic will be given in the spinal area to reduce any discomfort from the insertion of the needle used for a regional anaesthetic. When this has numbed the area, the anaesthetist will ask you to remain still so the needle can be directed to the right place. When the needle is inserted, you will be asked if you can feel anything. The procedure will not begin until the anaesthetist is certain you are fully numb.

How long do local anaesthetics take to wear off?

Local anaesthesia takes a few hours to wear off. When it does, you will have full feeling back, including any pain. You will be able to go home soon after the procedure.

It may take a while to regain all feeling after a regional anaesthetic. Also, because it can be difficult to sense when your bladder is full, as a precaution a catheter may have been inserted while you are under the anaesthetic so that your bladder will drain.

You should be able to go home when you have fully recovered and you have eaten and drunk and demonstrated that you can pass urine. You will probably be advised not to drive for a short time afterwards.

What are the side-effects?

Risks and complications of local anaesthesia are rare. Occasionally patients may experience redness of the skin and, rarer still, some people have an allergic reaction to the anaesthetic.

Risks and complications of regional anaesthesia:

• Bruising and soreness
• Confusion
• Dizziness and blurred vision
• Feeling faint
• Headache
• Nausea and vomiting
• Shivering

Less common side-effects:

• Nerve damage
• Small risk of infection
• Possible paralysis (rare)

Risks and complications of sedation:

• Amnesia or, more rarely, bad memories of the procedure
• Headache
• Nausea
• Sickness

Infolinks:

• The Royal College of Anaesthetists