The US government is undertaking an ambitious US$50 million project over five years to conduct emergency medical treatment without obtaining consent from patients. It will involve more than 20,000 people in 11 sites across the US and Canada.

Although consent is a basic principle of contemporary bioethics, it can be difficult to get it from people involved in accidents, shootings and heart attacks. For instance, in one experiment, medics will test which is the more effective treatment for cardiac arrests by randomly infused some patients with "hypertonic" solutions containing high levels of sodium, with or without the drug dextran. Other studies have suggested that hypertonic solutions could save more lives and minimise brain damage.

To allay fears of the public, researchers will conduct a "community consultation" process at each site. Anyone who objects will be provided with a special bracelet to alert medical workers.

Even bioethicists are divided on the issue. "This just seems like lazy investigators not wanting to try to get informed consent in situations where it is difficult to get it, so they say it is impossible," says George J. Annas, a prominent bioethicist at Boston University. "I don't think we should use people like this." However, Myron L. Weisfelt, of the Johns Hopkins School of Medicine, says that some people will object to any experiment done without consent. "We will never know the best way to treat people unless we do this research," he says. "And the only way we can do this research, since the person is unconscious, is without consent."