Now, an influential group of physicians in the United States has drafted a grimly specific list of recommendations for which patients would not be treated.

They include the very elderly, seriously hurt trauma victims, severely burnt patients as well as those with severe dementia.

The suggested list was compiled by a task force whose members come from prestigious universities, medical groups, the military and government agencies such as the Department of Homeland Security, the Centres for Disease Control and Prevention and the Department of Health and Human Services.

The proposed guidelines are designed to be a blueprint for hospitals 'so that everybody will be thinking in the same way' when pandemic flu or another widespread health-care disaster hits, said Dr Asha Devereaux, lead writer of the task force report.

The idea is to try to make sure that scarce resources - including ventilators, medicine as well as doctors and nurses - are used in a uniform, objective way, members said.

The recommendations appeared in a report yesterday in the May edition of Chest, the medical journal of the American College of Chest Physicians.

'If a mass casualty critical care event were to occur tomorrow, many people with clinical conditions that are survivable under usual health- care system conditions may have to forgo life-sustaining interventions owing to deficiencies in supply or staffing,' the report states.

As preparation, hospitals should designate a triage team with the God-like task of deciding who will and who will not get life-saving care, the task force wrote.

Those out of luck are the people at high risk of death and a slim chance of long- term survival.

Dr Kevin Yeskey, director of the preparedness and emergency operations office at the Department of Health and Human Services, said the report would be among many the agency reviews as part of preparedness efforts.

However, public health law expert Lawrence Gostin of Georgetown University has called the report 'a political minefield and a legal minefield'.

The recommendations would probably violate federal laws against age discrimination and disability discrimination, he said.

If followed to a T, such rules could exclude care for the poorest, most disadvantaged citizens who suffer disproportionately from chronic disease and disability, he said.

While health-care rationing will be necessary in a mass disaster, 'there are some real ethical concerns here'.

But the report could definitely guide hospitals in shaping their own preparedness plans even if they do not follow all the suggestions, said Mr James Bentley, a senior vice-president at the American Hospital Association.

Mr Bentley said this is not the first time this type of approach has been recommended for a catastrophic pandemic, but 'this is the most detailed one I have seen from a professional group'.

Compiling the list 'was emotionally difficult for everyone', said Dr Devereaux. That was partly because the task force's members believe it is just a matter of time before such a health-care disaster hits, she said.

'You never know, Sars took a lot of folks by surprise. We didn't even know it existed.'

ASSOCIATED PRESS