How the choice is made
Anaesthesia covers a wide range of care, from numbing a small patch of skin to a carefully controlled deep sleep. When I recommend an approach, I consider your medical history, the procedure you are having and how long it is likely to take, the position you will be in, your pain relief needs afterwards, and what you would prefer.
General anaesthesia
A general anaesthetic places you in a state of controlled, reversible unconsciousness. You are unaware of the procedure and feel no pain. It is used for most major operations and for many shorter ones.
It usually starts with medicine given through a drip in your hand or arm, and sometimes by breathing anaesthetic gas through a mask. Once you are asleep, the anaesthetic is maintained either with anaesthetic gases or with medicines given continuously through the drip. Your anaesthetist stays with you, monitoring and adjusting the anaesthetic throughout, then lets it wear off at the end so that you wake up in recovery.
Total intravenous anaesthesia (TIVA)
TIVA is a general anaesthetic given entirely through the drip, without anaesthetic gases. It may be chosen for some types of surgery, when monitoring of the brain and nerves is needed, or for people who have had significant nausea after previous anaesthetics.
Regional anaesthesia
Regional anaesthesia numbs a larger part of your body by placing local anaesthetic near a group of nerves. You may stay awake, have sedation, or have a general anaesthetic as well.
Spinal anaesthesia
A small injection in your lower back, through a very fine needle, numbs the nerves to the lower half of your body. Your legs feel heavy and numb, usually for a few hours. Spinals are used for some operations on the lower abdomen, hips, legs and urinary system.
Epidural anaesthesia
An epidural also involves an injection in the back, but a thin plastic tube is left in place so that medicine can be given continuously. It is often used for pain relief after major chest or abdominal surgery, as well as during childbirth.
Nerve blocks
Local anaesthetic is placed around the nerves supplying a specific area, such as an arm, shoulder, leg or part of the chest or abdominal wall. An ultrasound machine is commonly used to see the nerves and guide the needle. A nerve block can allow surgery on a limb while you are awake or sedated, and often provides good pain relief for many hours afterwards.
Local anaesthesia
Local anaesthetic is injected into the skin and tissues around the area being treated. It numbs only that area, and you remain fully awake. It is used for small procedures, and also alongside other techniques, for example where the surgeon numbs a wound at the end of an operation to reduce pain afterwards. You may feel pressure or movement, but you should not feel sharp pain.
Sedation
Sedation uses medicines, usually given through a drip, to help you relax and feel drowsy. It is commonly used for endoscopy, some radiology procedures, and with local or regional anaesthesia. Sedation can be lighter or deeper:
- Light sedation: you feel calm and relaxed, can talk and respond normally, and will probably remember parts of the procedure.
- Moderate (conscious) sedation: you are drowsy and may drift off to sleep, but can respond when spoken to or touched. Many people remember little afterwards.
- Deep sedation: you are deeply asleep and respond only to firm stimulation. Breathing and circulation can be affected, so this level requires an anaesthetist and careful monitoring.
Sedation is not the same as a general anaesthetic, and it is not always the right choice. Some people and some procedures are better and more safely managed with a general anaesthetic. The level that suits you will be discussed beforehand, and you are monitored throughout just as carefully.
Combining techniques
Techniques are often combined to give the best balance of safety, comfort and recovery. For example:
- a nerve block with a general anaesthetic for shoulder surgery, giving pain relief after you wake;
- a spinal anaesthetic with light sedation for a hip or knee operation;
- local anaesthetic with sedation for a procedure in radiology or a minor operation;
- an epidural with a general anaesthetic for major abdominal surgery.
Sometimes the plan needs to change during a procedure. For example, a procedure planned under sedation may need conversion to a general anaesthetic. When this is possible, I will discuss it with you beforehand.
Supporting your breathing
During a general anaesthetic, and sometimes during deep sedation, your anaesthetist supports your breathing. Once you are asleep, they may use:
- A laryngeal mask, a soft device that sits in the back of the throat above the voice box.
- A breathing tube (endotracheal tube), which passes between the vocal cords into the windpipe. It protects the lungs and is used for many longer operations, and when there is a higher risk of stomach contents reaching the lungs.
- A video laryngoscope, which uses a small camera to help place the breathing tube.
These devices are usually placed after you are asleep and removed before you are fully awake, so most people have no memory of them. A sore or dry throat afterwards is common and usually settles within a day or two. If you have been told your airway is difficult, or you have had problems before, please tell me. Occasionally a breathing tube is placed while you are awake and sedated, with your throat numbed, because that is the safest approach. If this applies to you, it will be explained in detail.
Further reading
- Types of anaesthesia (ANZCA)
- General anaesthetic (Healthdirect)
- Anaesthetics (overview) (Healthdirect)