U. ROCHESTER (US)—Blood transfusions should only be used as a last resort, according to a new study that finds they increase the risk of death for hospitalized cardiac patients by nearly five times and double the risk of infection.
Stronger, research-based guidelines for administering transfusions are needed since current clinical practice varies widely, says study coauthor Neil Blumberg, professor of pathology and laboratory medicine at the University of Rochester Medical Center.
“Doctors are simply doing what they were trained to do, but it turns out that their actions are more harmful than helpful in many cases,” Blumberg says. “This is an instance in which clinical practice got way ahead of research. And changing the liberal use of transfusions is going to be difficult despite the evidence showing it is usually not essential.”
Blumberg and lead author Mary Rogers of the University of Michigan Health System analyzed the records of nearly 25,000 Medicare patients in Michigan from admission to 30 days after discharge, all of whom received coronary bypass graft surgery from 2003 to 2006. They found transfusion practices after heart surgery varied by 30 percent at several hospitals.
Blood use among women patients ranged from 72.5 percent to 100 percent, and blood use among men varied from about 50 percent to 100 percent. Transfusions with donor blood were associated with infections of the genitourinary system, respiratory tract, bloodstream, digestive tract, and skin, according to the study.
The risk of death in the hospital was nearly five times greater among patients who received a blood transfusion, and the risk of death in the next 30 days was nearly three times greater. Some of the risk may have been due to the underlying condition that led to transfusion but Blumberg believes an increasingly convincing body of evidence demonstrates that some of the effect is due to the transfusion itself.
“Blood transfusions are certainly necessary in life-threatening situations,” Blumberg says. “But this study and other studies confirm they should be a last resort, not a first resort, as they often are.”
The study was published July 31 in the journal BMC Medicine and was funded by Blue Cross and Blue Shield of Michigan Foundation.
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