Red blood cell transfusion strategies.

Although the hemoglobin level of 100 g/L has been used for many years as the allogeneic red blood cell (RBC) transfusion trigger, current evidence indicates that for most patients a more restrictive transfusion strategy is at least as effective as and possibly superior to a liberal transfusion strategy. Moreover, the available data indicate that the use of smaller volumes of allogeneic RBCs may be associated with decreased risk of morbidity and mortality. Thus several recent studies indicate that the use of more restrictive triggers than 100 g/L does not appear to adversely affect patient outcomes. Indeed, the majority of recently published RBC transfusion guidelines recommend a more conservative and cautious approach to allogeneic RBC transfusion practice, primarily to reduce the risk of transfusion-related adverse effects. However, the available transfusion trigger studies do not provide sufficient data to allow the claim that the improved outcomes observed are the sole result of the transfusion strategy used. It is possible that the results are the consequence of effects yet to be defined clearly. Additional studies will be necessary to determine the effects of RBC storage time and the presence of allogeneic leukocytes in allogeneic RBC transfusion practice. Nonetheless, the available data, together with detailed information about alternatives to blood product transfusions, will enable physicians to improve outcomes in transfused patients.