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Anaesthetics (overview)

3-minute read

This page will give you information about different forms of anaesthesia. If you have any questions, you should ask your GP or other relevant health professional.

You can also download and print a PDF version of this factsheet, with space for your own questions or notes.

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. Local anaesthetics and other painkillers are injected down the catheter into the epidural space to numb your nerves.

Illustration showing a catheter in the epidural space.
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

Summary

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.

IMPORTANT INFORMATION
The operation and treatment information on this page is published under license by Healthdirect Australia from EIDO Healthcare Australia and is protected by copyright laws. Other than for your personal, non-commercial use, you may not copy, print out, download or otherwise reproduce any of the information. The information should not replace advice that your relevant health professional would give you.

For more on how this information was prepared, click here.

Last reviewed: September 2018

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Top results

Anaesthesia and day surgery | Sydney Children's Hospitals Network

What is general anaesthesia? A general anaesthetic is a mixture of medicines that put your child into a deep sleep during which they will not be aware or feel pain

Read more on Sydney Children's Hospitals Network website

Duration of Anaesthesia

How long will the local anaesthetic effect last? This depends on the type of local anaesthetic used and the region of the body into which it is injected.

Read more on ANZCA – Australian and New Zealand College of Anaesthetists website

Spinal Anaesthesia | myVMC

For information on spinal anaesthesia or epidural anaesthesia.

Read more on myVMC – Virtual Medical Centre website

RANZCOG WEBSITE - Pain Relief in Labour and Childbirth

An epidural is a procedure where an anaesthetic (a drug that gives either partial or total loss of sensation) is injected into the small space in your back near your spinal cord by a specialist anaesthetist

Read more on RANZCOG - Royal Australian and New Zealand College of Obstetricians and Gynaecologists website

Epidural

Labour is painful, so it' important to learn about all the ways that you can relieve the pain. Epidural is a type of local anaesthetic. Each method has advantages and disadvantages. Choose one that suits you.

Read more on Pregnancy, Birth & Baby website

Epidurals for pain relief in labour | Cochrane

Pain relief is important for women in labour. Pharmacological methods of pain relief include inhalation of nitrous oxide, injection of opioids and regional analgesia with an epidural for a central nerve block. Epidurals are widely used for pain relief in labour and involve an injection of a local anaesthetic into the lower region of the spine close to the nerves that transmit pain. Epidural solutions are given by bolus injection, continuous infusion or using a patient-controlled pump. Lower concentrations of local anaesthetic are needed when they are given together with an opiate, allowing women to maintain the ability to move around during labour and to bear down. Epidural analgesia may sometimes give inadequate analgesia, which may be due to non-uniform spread of local anaesthetic. Combined spinal-epidural involves a single injection of local anaesthetic or opiate into the cerebral spinal fluid for fast onset of pain relief as well as insertion of the epidural catheter for continuing pain relief. Side effects such as itchiness, drowsiness, shivering and fever have been reported and rare but potentially severe adverse effects of epidural analgesia do occur.

Read more on Cochrane (Australasian Centre) website

Epidurals and breastfeeding | Australian Breastfeeding Association

How does an epidural work?With an epidural, a small plastic tube is inserted between the bones of your spine, into the space around your spinal cord. A combination of drugs is given through the tube. A local anaesthetic blocks nerves in the spinal cord that transmit pain signals and an opiate provides further pain relief.

Read more on Australian Breastfeeding Association website

What is anaesthesia? ANZCA

The word anaesthesia is coined from two Greek words: "an" meaning "without" and "aesthesis" meaning "sensation". There are various types of anaesthesia.

Read more on ANZCA – Australian and New Zealand College of Anaesthetists website

Anaesthesia and risk in infants | Sydney Children's Hospitals Network

Modern anaesthesia and surgery is very safe for children and infants

Read more on Sydney Children's Hospitals Network website

Nerve Blocks (Regional Anaesthesia) | myVMC

Medical information about nerve blocks regional anaesthesia for treatment of pain

Read more on myVMC – Virtual Medical Centre website

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