Patient blood management during cardiac surgery: Do we have enough evidence for clinical practice?

Abstract

Transfusion of allogeneic blood products during and aftercardiac operations is common. When the degree of anemiaand the consequent decrease in oxygen deliverylead to organ ischemia, there is little doubt that red bloodcell (RBC) transfusion is necessary. In addition, treatmentwith fresh-frozen plasma and platelets may be necessaryto support coagulation. Treatment with bloodproducts may also aim to prevent hemodynamic instabilityfrom excessive postoperative blood loss. A large bodyof evidence, however, indicates that transfusion of bloodproducts per se may be associated with increased morbidityand mortality after cardiac operations.1-4 It is thereforeimportant to assess the real versus perceived needfor the transfusion of allogeneic RBCs and other bloodproducts by examining the risk–benefit profile of bloodproduct transfusion relative to the clinical condition ofthe patient. The risk–benefit profile of blood product transfusiondepends on many factors but is primarily based on thehemoglobin value. Other important factors include patientage, sex, hemodynamic profile, and signs of organ dysfunction.5,6 The risks of infectious disease transmission1 and immunologicsuppression,7 the costs, and a diminishing bloodsupply also contribute to the direct risk–benefit decisionanalysis and the overarching impetus to develop alternativesto blood component transfusion. The decision-making processethat determines whether to transfuse, when to transfuse,which blood products to transfuse, and how much of anyproduct to transfuse are indeed complex and need to includean evaluation of both the risks of transfusion and perioperativeanemia and a discussion about blood conservationstrategies.