Some patients having surgery for breast cancer will be offered a more limited form of anaesthesia than usual, to test whether they are less likely to be hit with a second bout of the disease.
There is some evidence to support this approach and Auckland City Hospital is joining a large international trial to see if it works.
"A couple of trials from 10 years ago, which were small retrospective studies, suggested there might be a difference for both breast cancer patients and prostate cancer patients," said anaesthetic fellow Dr Liz Maxwell, the local coordinator for the US-led trial which has received a grant from the NZ Breast Cancer Foundation.
"But those studies were not large enough to draw conclusions from.
"If it turns out that we could make a difference with a 15 to 20-minute procedure at a single point in the woman's pathway through treatment, that would be huge," Maxwell said.
Women in the trial will be offered regional anaesthesia for their full mastectomy or lump removal operation for first-time breast cancer, instead of, or in addition to, a general anaesthetic.
"It has to be primary breast cancer, and it can't have spread past the armpit," Maxwell said.
Regional anaesthesia numbs only the part of the body on which an operation is being done. It is the theme of National Anaesthesia Day, a promotion next Monday by the transtasman College of Anaesthetists to mark the 170th anniversary on Sunday of the day on which ether anaesthetic was first demonstrated publicly in Boston.
Information stands will be placed in hospitals for the public to learn about regional anaesthesia.
The college said the benefits of regional anaesthesia included good pain control, faster recovery, fewer side effects and less stress on the body.
"It can be safer for patients with obesity or lung disease. But it is not for every patient and every procedure."
In another piece of research, Auckland District Health Board anaesthetist Dr Tin Chiu is recruiting 50 elderly patients who have hip fracture surgery for a pilot study to test whether giving them regional anaesthetic for pain relief during and after surgery lowers their risk of delirium.
"A Greek study that offered patients regional analgesia every day of their hospital stay found that post-operative delirium decreased by 55 per cent," Dr Chiu said.
"We won't be continuing it for that long, but we want to see whether using a regional nerve block for pain relief in the 24 hours after surgery, instead of using opiods, decreases delirium."
At least half of patients who have an operation may become delirious afterwards, a problem that is linked to a higher rate of dementia and death in the five years after the surgery.
Patients who have had delirium after an anaesthetic and surgery are three times more likely than other elderly surgical patients to develop dementia within the next five years. They are also twice as likely to die within the following two years.
• The Breast Cancer Foundation is asking Kiwis to support its Pink Ribbon Appeal tomorrow and Saturday. Collectors will be accepting donations on streets and shopping centres to help pay for research, medical equipment, awareness and education programmes and support for women going through breast cancer.