National Anaesthesia Day acknowledges the efforts of the specialists who keep patients sedated and/or pain free during operations.
Contrary to popular misconception, those men and women are also doctors - and had gone through a training programme at least, if not more, rigorous than that of the surgeon, Dunedin Hospital consultant anaesthetist Andrew Smith said.
''You think medical school is hard until you undertake the subsequent training.''
Anaesthesiology involved both planning and monitoring, Dr Smith said.
Techniques and drugs were dependent on a range of variables, such as the type of patient, their age. type of operation, and whether the patient had any medical issues other than the one being operated on.
''You want someone to not feel pain, and if it's a general [anaesthetic] to not be aware of what's happening and to not remember anything,'' Dr Smith said.
''Children are more robust - they all tend to have very good hearts, very good lungs, very good kidneys and they can tolerate the anaesthetic a lot better than you might think
''At the other extreme, the elderly or frail often have other medical problems, have a risk of heart attack or stroke, have diabetes, or renal complications and you might need different techniques, such as other kinds of drugs which metabolise in different ways, different methods of pain relief, and also more monitoring.''
Modern drugs were short-acting and wore off more quickly, which generally reduced adverse responses to the anaesthetic, he said.
''Like all things, though, some people have more of a predisposition than others,'' Dr Smith said.
''Some people are more vomity and some aren't, like some people can happily sit on a boat in a force 9 gale and not get motion sickness, while others can sit on a flat pond and vomit everywhere.''
Anaesthesiology was a little like flying a plane, Dr Smith said: to a degree the patient could be left on ''auto-pilot'' once they were sedated, but the doctor always had to be watching closely in case anything unexpected occurred.
''You are there the whole time, constantly monitoring the patient, although some of the more manual monitoring we used to do has been replaced by machines, such as checking blood pressure,'' Dr Smith said.
''You have to keep a close eye on the surgeon because they may hit a blood vessel or run into surgical difficulties: you always need to know what they are doing and factor that into your plans.''
Dr Smith and some of his 28 colleagues at Dunedin Hospital spent yesterday explaining their work to colleagues, patients and hospital visitors, and demonstrating how to ventilate a patient.
