A team of clinical trial specialists and consumer advocates has concluded that blood substitutes increase death rates by 30% and nearly triple the risk of heart attacks. Not everyone buys the findings, however, and clinical trials in the field continue. Donated blood has a short shelf life, and the supply is often tight. For decades, researchers have tried to make blood from scratch. Although the products differ, all contain hemoglobin molecules that help deliver oxygen to the body's tissues. A number of products have been tested in trauma patients and various surgical settings, although none has yet been approved for...
