In the strict sense, the term anesthetist refers to any individual who administers anesthesia. In the US, however, the term is most commonly employed to refer to registered nurses who have completed specialized education and training in anesthesia to become certified registered nurse anesthetists (CRNAs). In the US and Canada, medical physicians who specialize in anesthesiology are called anesthesiologists. Such physicians in the United Kingdom (UK), Australia and New Zealand are called anaesthetists.
In the US, a physician specializing in anesthesiology typically completes four years of college, four years of medical school, and four years of postgraduate medical training or residency[6] According to the American Society of Anesthesiologists, anesthesiologists provide or participate in more than ninety percent of the forty million anesthetics delivered annually.[7] In the UK, this training lasts a minimum of seven years after the awarding of a medical degree and two years of basic residency, and takes place under the supervision of the Royal College of Anaesthetists.[citation needed] In Australia and New Zealand, it lasts five years after the awarding of a medical degree and two years of basic residency, under the supervision of the Australian and New Zealand College of Anaesthetists.[8] Other countries have similar systems, including Ireland (the Faculty of Anaesthetists of the Royal College of Surgeons in Ireland), Canada and South Africa (the College of Anaesthetists of South Africa).