Risks, benefits, alternatives and indications of allogenic blood transfusions.

Allogeneic red blood cell (RBC) transfusions are associated with multiple disadvantages, such as limited availability, high costs, multiple risks and side effects. In addition, large outcome studies comparing liberal (hemoglobin transfusion trigger range 9-10 g/dL) and restrictive (hemoglobin transfusion trigger range 7-9 g/dL) transfusion regimens still need to be performed for surgical patients. Different transfusion alternatives are known for the pre-, intra- and postoperative period. Autologous blood donation and erythropoietin are efficacious in the preoperative period. Intraoperatively, acute normovolemic hemodilution (ANH), cell salvage, antifibrinolytics, specific anesthetic and surgical techniques, coagulation monitoring, acceptance of minimal hemoglobin values and hopefully soon artificial oxygen carriers can reduce allogeneic RBC transfusions. In the postoperative period cell salvage, antifibrinolytics, and accepting minimal hemoglobin values represent alternatives to RBC transfusions. When treating a bleeding patient, the initial administration of crystalloids and colloids to restore and maintain normovolemia is important. RBC transfusions are recommended under the following circumstances: for hemoglobin levels <6 g/dL and for physiologic signs of inadequate oxygenation such as hemodynamic instability, oxygen extraction rate >50% and myocardial ischemia, detectable by new ST-segment depressions >0.1 mV, new ST-segment elevations >0.2 mV or new wall motion abnormalities by transesophageal echocardiography. The aim of this article is to review the efficacy, risk and side effects of RBC transfusions, to discuss transfusion alternatives and to summarize current indications for RBC transfusions. This information will help the physician to judiciously use RBC transfusions when they are indeed indicated.