NoBlood

Jan B. Wade · #1 (**permalink**) 01-15-2004, 09:25 PM

Artificial blood may get clinical trial in S.A. [oxygen-carrying fluid containing refined hemoglobin]

By Nicole Foy
San Antonio Express-News Web Posted : 12/17/2003 12:00 AM

Badly injured patients rushed to University Hospital may soon find themselves part of a potentially lifesaving, yet experimental, medical treatment involving artificial blood.

For years, physicians and scientists have grappled with how to keep critically injured patients from bleeding to death before reaching the hospital. Patients currently don't receive blood transfusions until they arrive at an emergency room.

But in recent years, several biotechnology companies have been developing and testing artificial products meant to serve as blood substitutes. The University Health System, with the University of Texas Health Science Center, is considering a clinical trial that would study one such substance, known as PolyHeme.

The product, an oxygen-carrying fluid containing refined hemoglobin, is compatible with all blood types. It has a longer shelf life than real blood, and it is more easily stored and transported for emergency care outside the hospital.

But participation in the study comes with a unique ethical catch. Many of the patients who will be enrolled in the experiment will not have given their consent.

That's because many of those in need of the product will be unconscious at the time they receive it. The trial now is aimed at only adult patients who are transported to University Hospital, a Level 1 trauma center, by San Antonio AirLife crews.

Officials at Brooke Army Medical Center, another such trauma center, are considering joining the study in the near future.

"This is the first time in San Antonio or South Texas that we've done a study where there is an exception to informed consent," said Dr. Ronald Stewart, the trauma medical director at University Hospital.

A possible scenario might involve a car crash victim, bleeding and unconscious at the scene of the accident. AirLife paramedics arrive and determine the patient is in hemorrhagic shock and is a candidate for receiving PolyHeme, so they begin the treatment.

At University Hospital, the treatment continues for a 12-hour period while staff attempts to reach the patient's legal representative or family members. Those people then may choose to withdraw the patient from the study, or the patient may do so upon regaining consciousness.

If the patient stays in the study, his or her medical status will be followed until either recovery or death, Stewart said.

The 12-hour treatment period is designed to mimic a situation in which blood is not available for an extended period of time, as in military combat, he said. The military, in particular, has been keenly interested in testing such artificial blood products for use on the battlefield.

Another group with a possible stake in the issue is Jehovah's Witnesses, who are called as part of their religion to refuse all whole-blood products, Stewart said.

It is possible that some such members may be open to accepting PolyHeme, since it is a blood derivative that contains only hemoglobin, not blood cells, he said.

Because the study requires an exception to the usual standard of informed consent, the University Health System and the health science center plan to hold a number of informational community meetings, at which physicians will explain how the trial and the product will work.

Only after the meetings will the health science center's investigational review board consider approving the trial â€” a necessary step toward PolyHeme's possible approval by the Food and Drug Administration.

If all goes as planned, AirLife patients could begin receiving the product in February or March, Stewart said.

Federal regulations allow patients to be enrolled in studies without their consent in certain circumstances: if patients are in a life-threatening situation, if the experimental treatment offers patients the potential for increased survival, if the risks are reasonable, and if the research could not be conducted without an exception from informed consent.