Hospitalized patients who received blood that had been stored for more than four weeks were nearly three times as likely to develop infections as those who received fresher blood, researchers said Tuesday.
The blood itself was not infected, but the release of chemical agents called “cytokines” by the stored blood may have affected the recipients’ immune systems, rendering them more susceptible to infections, said Dr. Racquel Nahra of Sparks Regional Medical Center in Fort Smith, Ark.
The patients typically suffered an increase in urinary-tract infections, pneumonia and infections associated with intravenous lines, but those who were infected were no more likely to die, she told a Philadelphia meeting of the American College of Chest Physicians.
The overall number of infections remained small, she said.
Current rules permit blood to be stored for 42 days before it must be discarded. Blood banks typically use the oldest blood on hand first.
The study and others like it highlight “a need for controlled studies on the effect of the age of blood on patient outcomes,” said Dr. Richard J. Benjamin, chief medical officer of the American Red Cross.
But, he added, “physicians and patients need to weigh the potential benefits against the small risk of harm caused by transfusion.” Los Angeles Times
