Blood transfusion in cardiac surgery: a silent epidemic revisited.

Mr Corazon is a 78-year-old man with insulin-dependent diabetes mellitus and an ejection fraction of 40% who is postoperative day 2 from coronary artery bypass grafting. He has been extubated and feels good, but he remains on a low-dose epinephrine infusion to support his blood pressure. His cardiac index is 2.2 L/m, and he has a mixed venous oxygen saturation of 59%. He has low filling pressures and marginal urine output. His hematocrit is 24%. His surgeon and his cardiologist confer and agree to transfuse him with 1 unit of red blood cells. They explain to him that he needs the blood transfusion and that the major risk of transfusion is the very low risk of viral infection. After the transfusion, his mixed venous oxygen saturation and urine output improve, and his epinephrine infusion is weaned off. He is transferred out of the intensive care unit the following day.