Cardiopulmonary Bypass Cases: To Hemodilute or Not?

As we dropped our patient off in the intensive care unit (ICU), I took a look at the chest tubes: bone dry. We had just finished a Bentall (aortic root plus valve replacement) in a middle-aged patient with a stenotic, bicuspid aortic valve and aortic root dilation. The patient had few other significant comorbidities and an excellent starting hemoglobin value of 14 g/dL, so I had opted to perform acute normovolemic hemodilution (ANH) in addition to our standard blood conservation techniques. We managed to get through the case without blood transfusion and were coming to the unit with a hemoglobin level >11 g/dL. Furthermore, the patient seemed euvolemic, on no vasopressors, and had excellent urine output. “So why don’t we do this for all our patients?” queried the resident. He asked a good question.