Types of anaesthesia

The three types of anaesthesia are general, regional and local. All three involve the administration of drugs to produce a change in sensation and they are frequently used in combination. Confusion sometimes arises, because the term “ local anaesthesia” is used to refer to what is properly called “ regional anaesthesia”, so that an operation “under local” may in fact be an operation using regional anaesthesia.

Factors that influence the choice of anaesthetic include:

  •  The procedure to be performed. Some procedures can only be performed under general anaesthesia. For example, a patient undergoing removal of the gallbladder, whether by means of a laparoscopic or key-hole technique or through a standard incision, needs a general anaesthetic. For other procedures it is reasonable to consider whether or not the operation should be carried out under local, regional or general anaesthesia, or if a combination of techniques should be used, such as combined regional and general anaesthesia. For example, a patient undergoing an examination of the knee using a special instrument called an arthroscope could be offered a choice of local, regional, or general anaesthesia. A patient undergoing an open-heart operation might be offered a combination of general anaesthesia and regional anaesthesia.
  • The experience, expertise and preference of the anaesthetist can vary with different techniques.
  • Your own preference – whether or not you would prefer to be unconscious or wish to remain as conscious and in control as possible. Most patients prefer to be unconscious for major surgical procedures. For some procedures it is increasingly common for patients not to have a general anaesthetic—for example, caesarean section.
  • Age – It is common for children to have a general anaesthetic for procedures that might be done without any form of anaesthetic in an adult, for example, MRI (magnetic resonance imaging) scanning. This is because children may not understand the explanations or be able to lie still.

Do you have a choice?

No matter what operation, examination or other treatment you are to undergo, you may ask your anaesthetist if there is any choice in the anaesthetic method. You should also understand that some surgeons are more comfortable operating on patients who have received one form of anaesthetic rather than another. This most often means that the patient has a general anaesthetic.

The surgeon does not choose the type of anaesthetic you will receive, unless there is no anaesthetist involved in your care. However, the surgeon may discuss the choice with you and with your anaesthetist. In the same way, your anaesthetist does not choose what operation you will have or how it will be carried out. Again, your anaesthetist may discuss your operation with you and your surgeon, particularly if you have special anaesthetic problems.

Can you choose your anaesthetist ?

It is sometimes possible to choose your anaesthetist, but there are factors which may make this difficult.

  • The anaesthetist you want may not have hospital privileges, which means that the anaesthetist is not legally entitled to practise medicine in a particular institution. This does not imply any lack of skill but rather indicates that the anaesthetist does not normally practise at that institution. (This may apply to surgeons as well.)
  • Some anaesthetists and surgeons often work as a team and develop a close working relationship. A particular anaesthetist may therefore not work regularly with a particular surgeon.
  • Other anaesthetists may choose to practise anaesthesia only for certain types of operations – for example, cardiac anaesthetists may not look after women undergoing labour and delivery, and paediatric anaesthetists may not provide anaesthetic care for adults.
  • Although an anaesthetist may work with a particular surgeon or provide care for a patient undergoing a particular operation, the anaesthetist may not regularly use a particular type of anaesthetic – for example, regional anaesthesia.
  • The anaesthetist might not be available, having been on call the night before, on holiday, or otherwise engaged.

Nevertheless, you are entitled to ask if you may have a particular anaesthetist look after you.

You have every right to ask questions, to receive information, and to participate in choosing the care you will receive. Asking questions and receiving information are the basis of giving informed consent for any medical procedure, including anaesthesia.


What does ‘informed consent’ mean ?

In many countries, including Canada and Australia, your doctor is obliged to give you the opportunity to know about the risks of the anaesthetic (or operation) that are serious or  material risks. The discussion that you have with your anaesthetist should include the possibility of a choice of anaesthetic method (if appropriate) and the risks and benefits associated with the choices. Only then should you agree or consent to undergo examination or treatment.

Having agreed to have the examination or treatment, you are then required to sign a piece of paper which describes the examination or treatment. Your signature should be dated and witnessed. This is known as giving written consent. However, written consent is normally obtained only for the operation or procedure for which an anaesthetic must be given. In Australia, Canada and the United Kingdom, a separate written consent for anaesthesia is not routinely obtained. This means that written consent for the operation includes consent for the anaesthetic. Occasionally, you may be asked to give separate written informed consent for the anaesthetic. This might occur if you agreed to undergo a technique that is not routinely carried out or one that involves considerable or unusual risk.

In fact, the piece of paper that you (and all patients) sign is only that – a piece of paper—although it is a very important one in the hospital admission process. What is more important is the discussion which you have with the treating doctor before signing the form. This discussion enables you to give consent on the basis that you understand the treatment and implications to your satisfaction. The consent you give after this kind of discussion is called informed consent.

What if you don’t want to have the operation ?

If you have second thoughts, even at the last minute, you should discuss them with your surgeon and your anaesthetist. Ultimately, the decision as to whether or not to proceed with the operation is yours.