Substitute blood trial worries ethicists
Boston paramedics could begin giving severely injured patients an experimental blood substitute without their consent this summer, as part of a national effort to improve the survival chances of victims of car accidents, gunshot wounds, and other injuries that cause profuse bleeding.
Under the experiment, which still requires approval from the ethics panel at Boston Medical Center, randomly selected trauma patients would immediately receive infusions of PolyHeme, a blood-based product that doesn't spoil as easily as natural blood. In early tests, PolyHeme has kept some patients alive even when they have lost virtually all their own blood. Paramedics normally administer saline solution, because blood breaks down quickly when it's not refrigerated.
Because severely injured patients are usually either in shock or unconscious, the small Illinois company that makes PolyHeme has received a waiver from the federal rule requiring that people give their consent to the experiment, which could be carried out at up to 20 hospitals nationwide. That sets off alarm bells among some medical ethicists, who fear patients being used unwittingly for research at the expense of their best interests.
"It raises major, major concerns," said George Annas, a medical ethicist at Boston University. "Just because you are in a car accident doesn't mean you can't give consent. . . . You have to first prove to me that it's impossible to get consent, and I don't think they've done that."
However, defenders of the experiment point out that 100,000 Americans bleed to death each year, thousands of whom might be saved if given blood before they reach the hospital. Many of those patients can't consent, and there's no time to find family members and determine whether they agree to participate in the experiment.
At an accident scene, the rescue squad "doesn't ask you if you want to be removed from your car" or be given cardiopulmonary resuscitation, said Dr. Richard Gamelli, who will lead the PolyHeme research at Loyola University Medical Center in Illinois if it is approved there. "We kind of have a social contract to do the right thing already." Dr. Erwin Hirsch, chief of trauma surgery at Boston University Medical Center, said his hospital is taking part in the research largely because of the paramedics themselves, who are frustrated they can't do more for patients at the scene. "They are the ones interested in doing the study," he said. "The impetus didn't come from the top down."Officials at Boston EMS, the city agency that provides paramedic service, declined to comment, saying they had not yet been formally briefed on the experiment. Hirsch points out that the public will be heavily informed before Boston paramedics begin administering PolyHeme. The US Food and Drug Administration is requiring extensive public meetings about the research, so that, theoretically, people can opt out. At community meetings in other states, officials from
For decades, researchers have looked for a blood substitute that would ease the shortage of donated blood and be less vulnerable to spoilage than human blood. Baxter Healthcare Corp. began testing a blood substitute in hospital operating rooms in the late 1990s, but stopped when it realized that the mortality rate for people receiving the product was more than twice that of people receiving conventional blood products.
But PolyHeme is a different, safer blood substitute, according to Dr. Steven A. Gould, president of Northfield Labs. In five clinical trials so far, he said, PolyHeme has proven safe even when given rapidly in large volumes. Most recently, the death rate among 171 patients who received rapid PolyHeme infusions was less than half the rate of those who didn't receive blood, according to a study in the Journal of the American College of Surgeons.
PolyHeme is derived from human hemoglobin, the molecules in red blood cells that carry oxygen, and is chemically treated to last 12 months, making it practical to carry on an ambulance.
Under the research proposed at Boston Medical Center, paramedics would decide on the scene whether the patient's injuries are severe enough to be part of the research. The paramedic would then open a sealed envelope that would say whether the patient receives PolyHeme or traditional saline. Researchers would then compare the 30-day survival rates of the two groups.
Hirsch stressed that while patients won't be asked for their consent at the injury scene, hospital staff will attempt to obtain consent for continuing use of PolyHeme at the hospital from either the patient or a family member.
But precautions at the hospital don't impress BU's Annas, who argues that it's unacceptable to continue giving people a blood substitute at the hospital without their consent. "We have blood," he said. "We know it works."
Northfield Labs hopes to test PolyHeme on 360 patients at 15 to 20 hospitals nationwide. That would translate into roughly 18 to 24 trauma patients in Boston receiving the blood susbstitute, though the number could differ substantially, according to Hirsch.
Scott Allen can be reached at allen@globe.com. Material from the Associated Press was used in this report.
