Transfusion Triggers in Cardiac Surgery

A high proportion of patients having cardiac surgery receive red cell transfusions. Yet, the investigators do not know whether transfusions are beneficial and they may be associated with harm. It is thus important to determine when a transfusion is required. The investigators will conduct a small pilot study at St. Michael\'s Hospital to address this issue. Patients having cardiac surgery will be allocated to one of two transfusion strategies with endpoints being compliance with the transfusion strategy and clinical outcome. The results of this study will be used to design a large definitive multicentered trial of these two transfusion strategies.