What is Anaesthesia?

This information is for prospective patients interested in learning general information about anaesthetists and surgical practices.

About anaesthesia

About 250,000 surgical procedures are carried out with anaesthesia in NZ each year.
This enables the patient to be unconscious and pain free during their operation.


The use of Anaesthesia is safer than it has ever been and regarded as one of the safest medical interventions. However, major complications can still occur, including the risk of dying. Statistically, the chance of mortality during an operation depends on the patient’s age and health.

Complications are more prevalent in the very young and elderly, and increase with obesity and smoking.  However, for a fit patient under 60 years of age, the chances of dying due to an anaesthetic complication is approximately 1 in 1,000,000. Mortality statistics for those undergoing anaesthesia over the age of 60 can be higher depending on co-existing conditions.


Other very rare occurrences from anaesthetic complications include: heart attack, stroke, major nerve damage, brain dysfunction, organ failure, allergic reaction and reawakening during a procedure.

Patients are given information prior to surgery by the anaesthetist when the patient is required to either interview, fill in a questionnaire, or attend a pre-admission clinic. As part of the NZSA’s commitment to Informed Consent, the Society produces the information leaflet, Your Anaesthetic, that may be given to patients by the hospital before a medical procedure about the risks associated with anaesthesia.



What is a trainee anaesthetist

Anaesthetists in New Zealand are among the most highly trained in the world.  After six years of Medical School they are required to work at least a further two years as doctors in the hospital system. After completing eight years, two of these as a qualified medical doctor, they are eligible to apply for the Anaesthesia Training scheme. Most trainees will have worked as Emergency Doctors or other specialties before applying for the Training Scheme.

Scheme selection

Selection for the scheme is very competitive and highly sought after.  Training is at least five years of full time work including two sets of exams; each requires at least 1000 hours of study. This will be on top of full time work averaging 50-65 hours per week.

During this five-year course the doctor is known as a Trainee Anaesthetist. In New Zealand’s hospital system they will be Anaesthetic Senior House Officers (SHO) for the first year, and then Anaesthetic Registrars until fully qualified. At times a final year trainee may have the title of ‘Fellow’ while doing more subspecialty training.

Anaesthetic Registrars have at least three years as a doctor, but usually many more. They will work under the direct supervision of a fully qualified Consultant Anaesthetist until they achieve a certain level of competency. As they become more capable they are allowed more autonomy, although senior back-up is always close as for most medical specialties in New Zealand.

During training

During their five years of training the trainee is rotated to anaesthetising every surgical specialty, as well as being exposed to all areas of medicine. They are among the most expert doctors at resuscitation. In rural hospitals they will be called to any emergency in the hospital. At larger hospitals they may be called to emergencies requiring advanced airway support or urgent surgery. They are skilled in all aspects in the stabilisation of acutely unwell patients. Training in Anaesthesia is generally necessary for all doctors working in Retrieval Medicine (Flying Doctors), Intensive Care or Emergency Medicine.

A career in anaesthesia

Anaesthetists are specialist doctors who administer different types of anaesthetic to make a patient unconscious and pain free during an operation or procedure. This involves the use of a complex range of drugs and highly technical equipment to monitor the patient’s condition throughout an operation. The anaesthetist is responsible for pain management after surgery and assessment of a patient’s medical condition prior to surgery to ensure they are fit for surgery.

Training period

Anaesthetists train for five years to obtain their medical degree and registration and a further five to seven years working as a registrar in a hospital, gaining practical experience and completing postgraduate exams before qualifying as a specialist anaesthetist. Specialist training includes managing all types of anaesthesia, a wide knowledge of general medical conditions, intensive care, trauma management and resuscitation, and the treatment of pain.

Each year about 45 trainees are employed in major secondary and tertiary hospitals in New Zealand. Completion of specialist training and exams enables vocational registration as a specialist anaesthetist.

Anaesthetists are supported in the operating theatre by anaesthetic technicians, nurses and perfusionists (trained health professionals who operate heart-lung machines during surgeries that require heart-lung bypass).

Employment options

Anaesthetists who work in public hospitals are employed by District Health Boards. Employment at private hospitals is undertaken after an anaesthetist is granted a ‘right to practise’ at the institution, and employment is typically on a casual basis and under an independent employment contract (not as a salaried employee). GPs or rural hospital doctors with additional training in anaesthesia may also work under the supervision of a qualified specialist anaesthetist.

There are also academic and research employment opportunities for anaesthetists through Medical Schools at Auckland and Otago universities.

History of Anaesthesia

Anaesthesia today is the culmination of many earlier discoveries and events. Surgical procedures are not a recent development. The skeletal remains of our earliest ancestors – the European Neolithic man – display evidence of possible surgery with surgical burr holes in the head. It is likely that such an event was to let out evil spirits.

By the times of the Greeks and Romans, surgical procedures, albeit fairly minor, were taking place. In ancient India, surgery was well advanced with the development of surgical instruments and even plastic surgical procedures have been described. (The surgical reconstruction of an amputated nose by the use a rotational flap has been described.)


Around 900-1000 AD the Arabs in Andalusia were performing abdominal surgery. Islamic surgeons and physicians described many operations and medical procedures, including bladder stones and caesarean sections. The Islamic practice of medicine was a thousand years ahead of western medicine and much of what was claimed as new was a rediscovery of ancient techniques lost to the West.

History of Anaesthesia: A list of important dates


500 BC Opium analgesia described by Hippocrates
1544 Ether synthesised    
1596 South American arrow poison described    
1628 Harvey describes the circulation    
1665 First IV injection of opium into a dog    
1776 Mesmer describes hypnosis    
1772 N2O discovered    
1796 Moore compresses nerves to produce local anaesthesia    
1829 Cloquet uses hypnosis for mastectomy    
1847 First veterinary treatment using anaesthesia, at Veterinary College London    
1848 First anaesthetic death. Hannah Greener aged 15 died after chloroform administration (she had had a toenail removed)    
1853 Invention of the hypodermic syringe and needle    
1860 Cocaine isolated    
1863 Popularisation of the use of N20    
1867 Prof Lister introduces antiseptic surgery    
1884 Demonstration of the local anaesthetic properties of cocaine on the cornea    
1894 Harvey Cushing advocated the use of anaesthetic record charts    
1898 August Bier introduced “spinal anaesthesia”    
1917 Boyle’s anaesthetic machine, a N2O and O2 machine, first described    
1920 Magill and Rowbotham developed endotracheal anaesthesia    
1929 Fleming discovers that the mould Penicillium notatum inhibits bacteria    
1930 The circle absorption system introduced by Brian Sword    
1932 Association of anaesthetists of Great Britain and Ireland formed    
1934 Thiopentone popularised
Australian Society of Anaesthetists formed
1939-42 An ear oxygen meter developed and term oximeter coined    
1940 Preparation of an active and concentrated form of penicillin described
1942 Muscle relaxants introduced
1945 The American Society of Anaesthetists formed
1948 The New Zealand Society of Anaesthetists formed
1951 Halothane synthesised     
1952 Faculty of Royal Australasian College of Surgeons formed
Pin index system introduced
1973 Prototype pulse oximeter used clinically    
1983 LMA use described    
1984 Propofol in soya bean oil introduced    
1987 First clinical use of desflurane    

Assistants to the anaesthetist

In operating rooms, or other areas where an anaesthetic is given, the NZSA strongly supports the presence of a trained anaesthesia assistant, whether an anaesthetic technician or registered nurse assistant to the anaesthetist.

Anaesthetic technicians work in the operating room with the anaesthetist and help to prepare and maintain equipment for an anaesthetic and to assist the anaesthetist to provide safe anaesthesia.

An anaesthetic technician does a two to three year (depending on an individual’s entry qualifications) hospital-based training course with distance learning which provides the academic component of this diploma or graduate certificate course. Anaesthetic technicians need to complete the Diploma in Applied Science (Anaesthetic Technology). This three-year extramural course is available through the Auckland University of Technology.

More information on the  New Zealand Anaesthetic Technicians' Society website.