The more red blood cells (RBCs) hospitalized patients receive in blood transfusions, the greater their risk of infection, according to a new study led by the University of Michigan Heath System and VA Ann Arbor Healthcare System. Researchers analyzed 21 randomized controlled trials for the study, which appears in the current Journal of the American Medical Association.
Elderly patients undergoing hip or knee surgeries were most susceptible, with a 30% lower risk of infection when fewer transfusions were used. Overall, for every 38 hospitalized patients considered for an RBC transfusion, one patient would be spared a serious infection if fewer transfusions were used.
The authors evaluated all healthcare-associated infections that were reported after receiving donor blood in the trials. These included serious infections such as pneumonia, bloodstream infections, and wound infections. Risks of additional hospital infections were particularly high for patients who already had sepsis. Patients with sepsis were twice as likely to develop additional infections when they received more transfusions.
“The fewer the red blood cell transfusions, the less likely hospitalized patients were to develop infections,” says lead author Jeffrey M. Rohde, MD. “This is most likely due to the patient’s immune system reacting to donor blood. Transfusions may benefit patients with severe anemia or blood loss; however, for patients with higher red blood cell levels, the risks may outweigh the benefits.”
Some 14 million red blood cell units were used in the United States in 2011, most often in the hospital. Lower hemoglobin thresholds are recommended by recent guidelines, but only 27% of hospitals that responded to the National Blood Collection and Utilization Survey reported using them after surgery. Read the study abstract.
