To evaluate of blood loss and determine criteria for blood transfusion, hematocrit levels are measures at 24 and 48 hours after surgery. The patients will receive a transfusion of one unit of packed red cells, if their hematocrit levels are less than 30% or if the compromised clinical criteria (such as hypotension, tachycardia, symptoms of anemia that are relative to the preoperative medical condition) necessitated blood transfusion. If hematocrit levels are less than 24%, two units of packed red cells are transfused. The hematocrit levels are reevaluated at 4 hours after the end of transfusion and blood transfusion is considered again using the same criteria. Drainage blood loss and amount of blood transfusion are recorded at 24 and 48 hours postoperatively.