He said last night that an Adelaide doctor had hypnotised some patients as their sole form of anaesthesia for major surgery.
"That's the extreme end, the dramatic end of what is possible."
He said patients with an active imagination were most likely to be successfully hypnotised and children aged 8 to 12 were among the most responsive.
"Most of us can get some sort of pain control by just being engaged in a good clinical interaction with good hypnotic technique."
"This means in the pre-operative period, anaesthetists and other clinicians can use a set of instructions and suggestions for the patient, creating expectations that are positive rather than potentially alarmist."
Well-designed childbirth trials had shown that the outcomes with hypnosis were "pretty good", he said.
"People deliver more comfortably, need less chemical analgesia and sometimes none at all. The babies come out fresher and in better condition."
Dental Association president Dr Geoff Lingard said some dentists used hypnosis to help patients reduce anxiety.
"You get patients who are more anxious than average. In those cases hypnotherapy can certainly be an effective aid to relaxing them and providing them with comfortable, pain-free dentistry."
Hypnotherapy could be used with oxygen and nitrous oxide analgesia.
"You are making suggestions to them that they are going to feel very relaxed, they are going to feel comfortable, they are not going to feel any pain."
Dr Large said the hypnotic process could begin with "gazing at a spot on the wall and letting everything else fade away into the background. Then suggestions [are made] about relaxation, just going off into a very safe and comfortable place in your mind. ... Suggestions can then be used to develop specific analgesia.
"There's no magic to it. People have that capacity within them to enter into an altered state of awareness. They really just need a bit of coaching to find it in a deliberate way."