Receiving blood from another person is linked with a two-fold increase in post-operative infection rates, according to a study.
Published in the open access journal BMC Medicine, the study on almost 25,000 coronary artery bypass graft (CABG) patients also found considerable hospital variation in transfusion practices.
Lead researcher Mary Rogers, from the University of Michigan in the US, said: "Clearly, blood transfusions are vital in the treatment of some conditions, such as life-threatening bleeding. However, over the past several decades a body of evidence has accumulated that indicates various adverse effects in patients who receive transfusions, particularly with exposure to allogeneic blood."
For their study, the researchers sought to assess hospital variation in blood use and outcomes in cardiac surgery patients, with a view to determining whether unnecessary blood transfusions might be putting the safety of some patients at risk.
They found that, overall, 30 per cent of the variation in transfusion practices was attributable to the hospital where the CABG was performed.
Rogers said: "The safety of patients undergoing CABG will likely be improved if hospitals carefully review current guidelines on allogeneic blood transfusion, closely adhere to such guidelines, and institute interventions to reduce inappropriate use of blood transfusions in recipients of CABG."