News of the Day ... In Perspective03/1/2006
Consent presumed for experiment with risky blood substitute
A patient who is taken to certain trauma centers, unconscious and in hemorrhagic shock, may receive a blood substitute instead of real blood as part of a randomized controlled trial—unless he is wearing a blue armband.
The blood substitute, called PolyHeme, is made by bursting open red blood cells in outdated blood and recovering the hemoglobin. The hemoglobin is polymerized in an effort to remove toxicity. Outside the red blood cells, hemoglobin seeps into blood vessel walls and causes inflammation.
The artificial blood eliminates the need for a type and cross match and has a long shelf life without refrigeration. It may reduce the risk of transmitting blood-borne infections.
An earlier study was shut down because 10 of 81 patients who received PolyHeme had a heart attack within seven days, while none of the 71 recipients of blood did. Other serious adverse effects such as arrhythmias and pneumonia occurred in 58% of PolyHeme recipients, but only 28% of controls. The results have not been published, but were obtained by the Wall Street Journal from internal documents of Northfield Laboratories.
A product such as PolyHeme would be extremely useful in combat situations or in remote areas where blood is unavailable without long delay. Although experimental subjects in such situations would have a much higher benefit-to-risk ratio than patients at an urban trauma center, it was judged too difficult and time-consuming to assemble a trial in remote areas.
Researchers held public meetings to inform people in the catchment area about the trial and their right to wear a blue armband to notify medical personnel of their refusal to participate. Conscious patients may refuse consent at any time.
Participating hospitals include the University of Texas Health Science Center at Houston, the University of Kentucky Medical Center, the Mayo Clinic, Duke Univerity, and Lehigh Valley Hospital in Allentown, Pa. (Thomas M. Burton, Wall St J 2/22/06).