The Associated Press

LOUISVILLE - The University of Kentucky Medical Center is participating in a clinical trial testing an experimental blood substitute and some critically injured patients may be receiving the substance without their consent.

The substance - PolyHeme - is compatible with all blood types. It is derived from human blood and is supposed to improve oxygen levels in people losing massive amounts of blood. Another advantage of the substance is that it has a shelf life of more than a year, compared with six weeks for blood.

Trauma surgeon Dr. Andrew Bernard, principal investigator for Kentucky's portion of the trial, said patients or family members are being asked permission whenever possible. But a goal of the trial is to gauge whether PolyHeme improves the chance of survival for severely injured trauma patients - most of whom are unconscious or unable to communicate.

Researchers have attempted to inform potential participants about the trial at UK through an advertising and public relations campaign and community meetings. Sometimes, Bernard said, risks are necessary to advance the cause of science.

"Somebody has to do a trial. That's medical research," Bernard said. "We must continue to challenge our current practices to make people better quicker."

Medical ethicists are divided on the consent issue, while some patient advocates say it is wrong, given the unknown risks.

"It's so important to gain consent," said Vera Hassner Sharav, president of the Alliance for Human Research Protection, a patient's rights organization. "It is a personal and individual right. It's a human right that we can't waive."

Dr. David J. Doukas, chairman of family medicine and medical humanism at the University of Louisville, said some people may consider unwittingly being part of an experiment a worse indignity than the possibility of dying. Sharav suggested that PolyHeme be tested instead on patients who can give consent, such as those undergoing surgery.

But Bernard said the goal of the study is to determine if it saves lives in the absence of blood. Answering that question, he said, could potentially help millions.

"Hemorrhagic shock is a major problem in trauma patients," Bernard said. "Developing a blood substitute could be very important."

UK is the only hospital in Kentucky that has joined the national trial. Two hospitals in Indianapolis also are participating in the trial, which involves 13 hospitals across the country and is expected to eventually include up to 25.

Manufacturer Northfield Laboratories Inc., of Illinois, targeted hospital researchers, who then decided whether to sign up. The company expects to enroll 720 patients nationwide in the study, which is expected to run into next year.

Unlike the salt water solution normally given to bleeding patients in ambulances to keep them hydrated until they reach the hospital, PolyHeme carries oxygen. Since May, the brownish-colored blood substitute has been carried on ambulances in some central Kentucky counties and most emergency medical helicopters in the state.

To receive the blood substitute, a patient must be at least 18 years old, have a certain low blood pressure level and be en route to a participating hospital.