New blood transfusion studies in brief

CAP Today

December 2010
Feature Story

The two recent JAMA studies on blood transfusion report findings of 1) the TRACS randomized, controlled trial on liberal versus restrictive transfusion policies after cardiac surgery in Brazil, and 2) an assessment of cardiopulmonary bypass data at 798 hospital sites in the United States.

The TRACS trial (Transfusion Requirements After Cardiac Surgery) was conducted in an intensive care unit at a university hospital in Brazil (Hajjar LA, et al. JAMA. 2010;304:1559–1567). The researchers assigned patients randomly to a liberal strategy of blood transfusion (to maintain a hematocrit ≥30 percent) or to a restrictive strategy (hematocrit ≥24 percent). The key finding: Independent of transfusion strategy, the number of transfused red cell units was an independent risk factor for clinical complications or death at 30 days. “Among patients undergoing cardiac surgery, the use of a restrictive perioperative transfusion strategy compared with a more liberal strategy resulted in noninferior rates of the combined outcome of 30-day all-cause mortality and severe morbidity,” the authors conclude.

The U.S. hospitals cardiopulmonary bypass observational study looked at 102,470 patients undergoing primary isolated cardiac artery bypass graft surgery during 2008, and measured perioperative transfusion of RBCs, fresh-frozen plasma, and platelets (Bennett-Guerrero E, et al. JAMA. 2010;304:1568–1574). The key findings: After adjustment for patient-level risk factors, the factors of geographic location, academic status, and hospital volume explained only 11.1 percent of the variation in hospital risk-adjusted RBC usage. Case mix explained 20.1 percent of the variation. The authors conclude, “Wide variability occurred in the rates of transfusion of RBCs and other blood products, independent of case mix, among patients undergoing CABG surgery with cardiopulmonary bypass in U.S. hospitals in an adult cardiac surgical database.”

—Anne Paxton