There are several types of anaesthetic which may be employed for your operation. The 3 broad types are:
These may be used individually or in combination.
During general anaesthesia your body is in a state of unconsciousness and you will be unaware of anything during the operation. Your anaesthetist will administer the anaesthetic either as injections, gases or a combination of these.
Usually the first step is to inject medication into the vein, through a small plastic tube (cannula), often placed in the back of a hand. This induction puts the body into an unconscious state and to maintain this, you will be given either a continuous infusion of the same medications or breathe an anaesthetic gas.
While you are unconscious and unaware, your anaesthetist remains with you at all times, monitoring your condition, controlling the anaesthetic and replacing fluid or blood. At the end of your operation the anaesthetist will reverse the anaesthetic and you will regain conscioiusness, either in the theatre or the recovery room.
This is where local anaesthetic is injectedaround a nerve or bundle of nerves, so that part of the body, such as an arm or leg is made numb. In addition to losing the sensation, the muscles may also be affected and the arm or leg may be weak for some time.
The advantages of this sort of anaesthetic are that you do not need to go to sleep and therefore you do not get the side effects of a general anaesthetic which may include drowsiness, nausea or a sore throat. It also allows for a long duration of pain relief, as the local anaesthetic can last for many hours after your operation.
Examples of regional anaesthesia are the use of an epidural for pain relief during childbirth, a spinal anaesthetic for operations on the bladder and an eye block for a cataract operation.
Sometimes regional and general anaesthesia can be combined, where you need to be unconscious for the operation, but need prolonged pain relief after the procedure.
In this form of anaesthesia, a local anaesthetic drug is injected into the skin and tissues at the site of the operation. The are of numbness will be restricted and a sensation of pressure may be present, but there should be no pain. This form of anaesthesia is used for minor procedures and will usually be given by the doctor performing the operation.