But Haut said the risks aren't as bad as they once were, and doctors have come up with better ways of determining good plasma matches. For instance, women who have had multiple children are not good plasma donors, he said.
Nearly 40 percent of patients who end up at shock trauma need blood transfusions, and bleeding complications are a leading cause of early death among trauma patients.
"What we need is the hard evidence on whether one ratio is better than the other," said Col. Dallas Hack, director of the Combat Casualty Care Research Program for the Army and Defense Health Program, which is funding the study. "This is the final major step to give us that evidence."
Maryland Shock Trauma Center has used community consultation for at least three studies in the past decade and a half, Scalea said. Without community consultation, real-time testing on patients would be nearly impossible, he said. Instead, researchers would have to rely on data collected on past cases, a method of research he argued is less reliable.
Scalea said a trial in the 1990s that used community consultation led to changes in procedures he believed eventually saved lives. Before the study doctors gave patients fluid to try to normalize low blood pressure, but researchers determined giving fluid had no benefit and that normalizing blood pressure led to more bleeding.
"We [now] will allow your blood pressure to stay low for a while so you won't hemorrhage," Scalea said.
But there is no guarantee every trial will have positive results, raising concerns among some ethicists about the use of community consultation.
Shock Trauma researchers have started reaching out to people through newspaper and radio advertisements directing them to a website about the study, umm.edu/shocktrauma/bloodstudy. They will spend at least the next month or so trying to reach people at community meetings, churches and events.
They planned for a booth at the Baltimore Running Festival, and to inform people at farmers' markets. They also are working with government agencies, such as the state Department of Health and Mental Hygiene, on ways to reach people.
Because the FDA allows so few studies to use community consultation, there are strict guidelines. The studies are reviewed carefully by the FDA and require approval and oversight of an institutional review board throughout the investigation. The study at Maryland Shock Trauma Center already has spent two years getting the proper approvals.
The FDA requires such studies to be disclosed publicly and the IRB must approve community consultation activities. The FDA doesn't say specifically what amounts to sufficient community consultation.
The study will be halted immediately if it is found patients are being harmed. It also will be stopped early if no significant results are found. Scalea said he feels the process protects patients while allowing for cutting-edge research.
"The FDA has determined this is an ethical way to do this." Scalea said.
Despite the efforts to spread word of the study, some ethicists say it is impossible to reach enough of the community to gather consensus. Maryland Shock Trauma Center treats a large number of gunshot victims involved in Baltimore city's drug trade, for instance. Will Maryland researchers be able to reach this population?
"There is no way you can reach everybody," Annas said. "It's more symbolic than real. You're trying to say consent is important when it really is not."
Scalea conceded that it is impossible to reach everyone, but said a good cross-section of the population is achievable.
"Are we going to get to all 5 million people in the state of Maryland? No," Scalea said. "Are we going to do our very best to do this ethically with all the best intentions? Absolutely."
Scalea said armbands are a good tool for identifying people who don't want to participate and that citizens have to take a personal responsibility to stay informed.
"If you don't want to play all you have to do is wear the armband," Scalea said. "We are happy to give you as many armbands as you want. You can change them every day."
Others doubted people would consider wearing armbands to be a serious option.
"This notion that you can refuse consent with an armband is hilarious," said Leonard Glantz, a professor of health law, bioethics and human rights at the Boston University School of Public Health. "The whole idea is silly. There is no evidence that a lot of people will wear an armband."
Bioethicists said community consultation also raises concern in African-American communities where distrust of medical studies is ingrained. And many others, no matter their race, don't want to be the subject of an experiment.
"There is some apprehension, which I frankly think is for the most part misplaced," Scalea said. "I think people say, 'I don't want you to experiment on me.' But if you come in here and I'm on call you get this, and if my partner is on call you get that."
Hopkins' Haut agrees that community consultation in lieu of individual consent is a valid way of conducting research. He expects more studies to use the tool.
"There are really important questions in trauma and emergency research that are hard to do without community consent," he said.