A victim of severe trauma who gets as little as a single unit of blood that's been stored for more than a month is twice as likely to die as an equally injured patient who gets transfused with fresher blood, a new study finds.
Red blood cells stored longer than 28 days significantly increased trauma patients' risk of developing fatal deep vein thrombosis or multi-organ failure for six months after transfusion, a team of pediatric intensive-care specialists in Connecticut reported today in the journal Critical Care.
The new study is the latest to raise concerns about rules governing the use of about 29 million units of blood transfused every year in the United States. The American Red Cross says donated blood has a "shelf life" of 42 days, after which it must be discarded if not used.
Two earlier studies -- one looking at a general hospital population requiring transfusion and a second at heart surgery patients -- found that the use of longer-stored blood in transfusions resulted in poorer outcomes. Hospital patients administered blood stored longer than four weeks were three times as likely to acquire an infection in the hospital than those who got fresher blood. Heart patients infused with blood stored longer than two weeks were 64% more likely to die than those whose red blood cells were more briefly in storage.
Though hospitals typically use their longest-stored blood first to avoid wasting the precious resource, the authors of the Critical Care study suggest that physicians might consider the "preferential use" of younger blood on the most critically injured trauma patients. The result would likely mean more blood reaches its expiration date before it can be used. But lives could be saved.
-- Melissa Healy