Types of anaesthesia

There are several types of anaesthesia that may be used individually or in combination, depending on the surgery.

For some types of surgery, several options are available. Except in emergency situations, specialist anaesthetists will consult with the patient and the surgeon to decide on the safest and most appropriate type of anaesthesia for each clinical situation. The anaesthetist will consider several factors when planning a patient’s anaesthesia including:

  • Past experience with surgery.
  • Health and physical condition.
  • Reactions or allergies to medicines.
  • Risks of each type of anaesthesia.
  • Preferences of your surgical team.
  • Your preferences.

Local anaesthesia

Local anaesthesia involves injecting local anaesthetic into the tissues near the surgical site. Local anaesthesia may be used alone or in combination with sedation or general anaesthesia. This depends on the size of the surgery and the time it will take, and the preferences of the patient. Local anaesthesia is usually used for minor surgery, such as toenail repair, skin lesion or a cut to remove something. It may not be used if the patient has an infection.

Regional anaesthesia

In this video Professor David A Scott, Director of Anaesthesia at St Vincent's Hospital, Melbourne and a recent patient of his discuss the benefits of staying awake during surgery.
Regional anaesthesia involves injecting local anaesthetic around major nerve bundles supplying body areas, such as the thigh, ankle, forearm, hand, shoulder or abdomen. It may be used on its own or with general anaesthesia. Regional anaesthesia is sometimes performed using a nerve-locating device such as a nerve stimulator, or using ultrasound, to accurately locate the nerves. Once local anaesthetic is injected, patients may experience numbness and tingling and it may become difficult or impossible to move that part of the body

The duration of the anaesthesia depends on which local anaesthetic is used, the region into which it is injected and whether it is maintained by continual doses or repeated injections. Numbness can last several hours but may last several days. Generally, the “heaviness” wears off within a few hours but the numbness and tingling persists much longer. As the local anaesthetic effect wears off, numbness will diminish and the surgical pain may return, in which case your doctor will prescribe pain relief.


Conscious sedation reduces the patient’s level of consciousness but allows them to respond to verbal commands or light touch so that a specialist can perform a procedure. A variety of medications and techniques are used for procedural sedation and/or pain relief. Common medications include benzodiazepines, such as midazolam, which act on the brain and the nervous system to cause sedation, and opioids, such as fentanyl, which decrease the patient’s perception of pain to provide pain relief. These medications may be administered orally but are usually administered into a vein.

Deep levels of sedation, where patients lose consciousness and respond only to painful touch, may be associated with the patient having difficulty breathing normally and their heart function may be affected. The anaesthetist is trained to manage these situations.

General anaesthesia

General anaesthesia involves putting a patient into a medication-induced state of carefully controlled unconsciousness. When the anaesthetic is deep enough, the patient will not respond to pain. It also includes changes in breathing and circulation. During a general anaesthetic, the anaesthetist is constantly monitoring the patient to manage the airway, blood circulation and general responses.

Please note: This information is a guide and should not replace information supplied by your anaesthetist. If you have any questions about your anaesthesia, please speak with your treating specialist.

Last updated 09:09 30.06.2020