Recombinant human erythropoeitin: efficacy and safety considerations for maximizing blood conservation in cardiac surgery.

B LOOD products transfused to patients undergoing cardiac surgery consume approximately 15% of the banked blood supply in the United States. Cardiac surgical patients known to be at particular risk for receiving allogeneic blood transfusions in the perioperative period include patients with preoperative anemia and patients undergoing surgeries other than primary coronary artery bypass grafting operations. In this issue of ANESTHESIOLOGY, Yoo et al. report results of a singlecenter randomized controlled trial (RCT) of preoperatively anemic valvular heart surgery patients who a day before surgery received either 500 IU/kg of IV recombinant human erythropoietin (rhEPO) plus iron supplement (n 37), or a placebo bolus of normal saline (n 37). Interestingly, despite the short interval between rhEPO administration and initiation of surgery (16–24 h), subjects in the rhEPO group were significantly less likely than subjects in the placebo group to receive packed erythrocyte (PRBC) transfusions during the perioperative period spanning surgery and the first 4 postoperative days (59% compared with 86%; P 0.009). Furthermore, subjects in the rhEPO group who received PRBCs were transfused with significantly fewer units than subjects in the placebo group (1.6 0.9 units/patient vs. 3.7 2.1 units/patient; P 0.004). The results of this RCT are encouraging regarding potential for rhEPO to be used as an effective component of multimodal efforts to minimize perioperative blood transfusions in anemic patients undergoing valvular heart surgeries. A key strength of the study by Yoo et al. is that it enrolled patients known to be at increased risk for receiving perioperative PRBC transfusions (i.e., preoperative anemia and need for valvular surgery). Prior studies of rhEPO have enrolled populations of primarily coronary artery bypass graft surgery patients who were not selected for having preoperative anemia. Still, 59% of the patients in the rhEPO intervention group received perioperative PRBC transfusions, suggesting that the work by Yoo et al. should provide a starting point for future studies designed to test alternative rhEPO blood conservation approaches that could reduce PRBC use even further. Mitigating allogeneic PRBC transfusions, particularly in higher risk cardiac surgical groups, is important for reducing risks of transfusion-related infections and immunologic reactions, and for decreasing consumption of a limited health care resource. Furthermore, observational studies suggest that PRBC transfusion should be limited as much as possible because it is associated with increased morbidity and mortality after cardiac surgery. Subjects in the rhEPO group of the Yoo et al. study received a mean of 1.6 units of PRBC, so it is plausible that additional blood conservation measures could reduce need for transfusion in considerably more of these higher-risk patients. Consistent with the 2011 Update to the Society of Thoracic Surgeons and the Society of Cardiovascular Anesthesiologists Blood Conservation Clinical Practice Guidelines, subjects in both arms of the Yoo et al. study intraoperatively received the lysine analog tranexemic acid, and a red cell salvage device was utilized, allowing reinfusion of salvaged red blood cells. However, the prime volume used in the cardiopulmonary bypass (CPB) circuit in the study was 1.6 l, suggesting that perioperative transfusion might be further reduced by implementing other recommendations from the Society of Thoracic Surgeons and Society of Cardiovascular Anesthesiologists Blood Conservation Clinical Practice Guidelines, such as retrograde autologous CPB circuit prim-