General anaesthesia is a state of controlled unconsciousness during which you feel nothing. You will have no memory of what happens while you are anaesthetised. A general anaesthetic is required for a very wide range of operations. This includes most major operations on the heart, lungs or in the abdomen, and many operations on the brain or the major arteries. Anaesthetic drugs are injected into a vein, or anaesthetic gases are given to you to breathe. These drugs stop the brain from responding to sensory messages travelling from nerves in the body. Anaesthetic unconsciousness is different from a natural sleep. You cannot be woken from an anaesthetic until the drugs are stopped and their effects wear off. While you are unconscious, the team in theatre look after you with great care. Your anaesthetist stays near to you all the time.
A local anaesthetic numbs a small part of the body where you are having the operation. It is used when nerves can be easily reached by drops, sprays, ointments or injections. You stay conscious, but free from pain. Common examples of surgery using local anaesthetic are having teeth removed and some common operations on the eye.
This is when a local anaesthetic drug is injected near to the nerves that supply a larger or deeper area of the body. The area of the body affected becomes numb.
Spinal and epidural anaesthesia
Spinals and epidurals are the most common types of regional anaesthetics. These injections can be used for operations on the lower body, such as caesarean section, bladder operations or replacing a hip. You stay conscious, but free from pain.
Other types of regional anaesthesia
Other types of regional anaesthetics involve an injection placed near to a nerve or group of nerves, for example in the arm or leg. This is often called a ‘nerve block’ and can allow you to have the operation without a general anaesthetic. Nerve blocks are also useful for pain relief after the operation, as the area will stay numb for a number of hours.