Blood use in elective surgery: the Austrian benchmark study

BACKGROUND: Benchmarking transfusion activity may help to eliminate inappropriate use of blood products. The goal of this study was to measure and to compare the current transfusion practice and to identify predictors of transfusion in public hospitals to develop strategies to optimize transfusion practices. STUDY DESIGN AND METHODS: This was a prospective observational study in 18 randomly selected public hospitals from April 2004 to February 2005. Primary outcome measures were the amount of intra- and postoperative blood components transfused and intercenter variability of transfusion rate. Secondary outcome measures were prevalence of preoperative anemia, calculated perioperative blood loss, and lowest measured perioperative hemoglobin (Hb) level. RESULTS: Adult patients undergoing primary unilateral total hip replacement (THR, n = 1401), primary unilateral knee replacement (TKR, n = 1296), hemicolectomy (HECOC, n = 148), and coronary artery bypass graft (CABG) surgery (n = 777) were enrolled. Due to the small number, data of HECOC patients were not fully analyzed. In the remaining procedures, there was a large intercenter variability in the percentage of patients who received transfusions: THR 16 to 85 percent, TKR 12 to 87 percent, and CABG 37 to 63 percent. In the patients who received transfusions, the number of red blood cells (RBC) units transfused varied significantly. There was also a considerable intercenter variability in RBC loss. The prevalence of preoperative anemia was 19 percent and identical in both sexes. The incidence of preoperative anemia was three times higher in patients who received transfusions compared to those who did not. CONCLUSION: This study demonstrates a high intercenter variability in RBC transfusions and RBC loss in standard surgical procedures. Whereas the variability in blood loss remains largely unexplained, the main predictors for allogeneic RBC transfusions are preoperative and nadir Hb and surgical RBC loss.