There are different forms of anaestheisa that can be used to provide a safe and effective way for you to have an operation or procedure, and to give you pain relief. Most people do not have any problems and are satisfied with their anaesthetic.

What is an anaesthetic?

An anaesthetic is a combination of drugs that causes loss of sensation.

What is a general anaesthetic?

A general anaesthetic is a combination of drugs that causes deep sleep. You will not be aware of what is happening and afterwards you will not remember anything that has happened.

Most people are sent to sleep by injecting the anaesthetic through a drip (small tube) in a vein. It takes about 30 seconds to work.

For some people it may be more appropriate to go to sleep by breathing an anaesthetic gas through a face mask. This also takes about 30 seconds to work.

What is an epidural or spinal anaesthetic?

An epidural or spinal anaesthetic involves injecting local anaesthetics and other painkillers near your spinal cord to give pain relief in certain areas of your body.

A fine catheter (tube) is inserted in the epidural space, near your spinal cord (see figure 1). Local anaesthetics and other painkillers are injected down the catheter into the epidural space to numb your nerves. A catheter in the epidural space

What is a local anaesthetic?

A local anaesthetic temporarily stops nerves working so that you do not feel pain. The anaesthetic can be injected just around the area where the operation is going to take place. It is possible to numb the nerves to your arm or leg (called a nerve block).

What complications can happen?

General anaesthetic

Minor complications include feeling sick, sore throat, difficulty passing urine and headache. The following are the possible serious complications.

  • Loss or change of hearing
  • Eye injury
  • Nerve injury
  • Heart attack
  • Stroke
  • Chest infection and other breathing problems
  • Allergic reaction

Epidural or spinal anaesthetic

  • Failure of the epidural or spinal
  • Low blood pressure
  • Headache
  • Infection around your spine
  • Cardiovascular collapse
  • Short-term nerve injury
  • Blood clot around your spine
  • Paralysis or death

Local anaesthetic

  • Not enough pain relief
  • Allergic reaction
  • Bleeding
  • Nerve damage
  • Absorption into your bloodstream


Author: Dr Iain Moppett DM MRCP FRCA

Illustrations: Medical Illustration Copyright © Nucleus Medical Art. All rights reserved.

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Last updated: July 2017

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