The case–control study, which included more than 160 cardiac surgery patients, showed those who received transfusions of red blood cells (RBCs) that had been in storage for more than three weeks were more than twice as likely as those who received fresher blood to experience delirium.
The study addressed a serious postoperative complication, said Aryeh Shander, MD, president of the Society for the Advancement of Blood Management, who was not involved in the research. However, he said it is only hypothesis-generating at this point.
“We need to have some kind of biologic, or chemical or physiologic connection between the two variables, and at the moment there is none,” said Dr. Shander, who is also chief of the Department of Anesthesiology, Critical Care and Hyperbaric Medicine at Englewood Hospital and Medical Center in Englewood, N.J. “The association might have nothing to do with blood age. One possibility is that transfusion, on its own, may be associated with delirium, but that’s difficult to separate out because there are so many confounders.”
The researchers presented their findings at the 2013 annual meeting of the Society of Cardiovascular Anesthesiologists (abstract 86).
Lead investigator Charles Brown, MD, assistant professor of anesthesiology and critical care medicine at The Johns Hopkins University School of Medicine, in Baltimore, and his colleagues set out to investigate the possible correlation between age of blood and delirium in light of prior evidence that transfusion of older blood can increase the risk for other morbidities as well as death.
The full article is located at Anesthesiology News