Studies have shown that red blood cell (RBC) transfusions are commonly performed, with approximately 14 million units transfused in 2011 in the United States. RBC transfusions can modulate the immune system, which in turn may impact infection risk. One approach in blood management is to use a restrictive threshold transfusion strategy in which the hemoglobin thresholds at which RBC transfusions are indicated are lowered.

“The restrictive strategy is recommended by guidelines, but only about 27% of hospitals report using them after surgery,” says Jeffrey M. Rohde, MD. In addition, only 31% of hospitals report having a blood management program in place to optimize the care of patients who might need a transfusion.

A Systematic Review & Meta-Analysis

Dr. Rohde and colleagues conducted a systematic review and meta-analysis of 21 randomized trials that compared restrictive and liberal RBC transfusion strategies. Published in JAMA, the article evaluated whether RBC transfusion thresholds were associated with risk of infection and whether these risks were independent of leukocyte reduction. The study included more than 8,700 patients who met eligibility criteria. All healthcare-associated infections reported after receiving donor blood in randomized trials were evaluated, including serious infections like pneumonia and bloodstream and wound infections.

Transfusion-Infection-Callout

According to the results, a restrictive RBC transfusion strategy reduced the risk of healthcare-associated infections when compared with a liberal transfusion strategy. “The more RBCs that patients received, the greater their risk was for infection,” says Dr. Rohde. “The fewer the RBC transfusions, the less likely hospitalized patients were to develop infections.” He adds that these findings were most likely due to transfusion-associated immunomodulation.

Overall, for every 38 hospitalized patients considered for an RBC transfusion, one patient would avoid a serious infection if a restrictive strategy was used. Elderly patients undergoing hip or knee surgeries were most susceptible in the study. These individuals had a 30% lower risk for infection when a restrictive strategy was used. Risks of additional hospital infections were particularly high for patients who already had sepsis. These patients were twice as likely to develop additional infections when they received more RBC transfusions.

Important Implications

Dr. Rohde says that transfusions may benefit patients with severe anemia or blood loss but notes that the risks may outweigh potential benefits for patients with higher RBC levels. “In light of our findings, clinicians should recognize that implementing restrictive strategies has the potential to lower the incidence of healthcare-associated infections,” he says. “Patients should also be made aware of the potential risks associated with RBC transfusions. Hospitals can also be proactive by making efforts to ensure that blood management programs are available to patients.”

References

Rohde JM, Dimcheff DE, Blumberg N, et al. Health care–associated infection after red blood cell transfusion: a systematic review and meta-analysis. JAMA. 2014;311:1317-1326. Available at: http://jama.jamanetwork.com/article.aspx?articleid=1853162.

Hajjar LA, Vincent JL, Galas FR, et al. Transfusion requirements after cardiac surgery: the TRACS randomized controlled trial. JAMA. 2010;304:1559-1567.

Horvath KA, Acker MA, Chang H, et al. Blood transfusion and infection after cardiac surgery. Ann Thorac Surg. 2013;95:2194-2201.

Carson JL, Terrin ML, Noveck H, et al; FOCUS Investigators. Liberal or restrictive transfusion in high-risk patients after hip surgery. N Engl J Med. 2011;365:2453-2462.

Rogers MA, Blumberg N, Saint S, Langa KM, Nallamothu BK. Hospital variation in transfusion and infection after cardiac surgery: a cohort study. BMC Med. 2009;7:37.

Rogers MA, Blumberg N, Saint SK, Kim C, Nallamothu BK, Langa KM. Allogeneic blood transfusions explain increased mortality in women after coronary artery bypass graft surgery. Am Heart J. 2006;152:1028-1034.