This issue of CHEST contains an article written by Avorn and associates (see page 1437) entitled, “Hetastarch and Bleeding Complications After Coronary Artery Surgery.” Bleeding is a major concern for surgeons in the perioperative period. Reoperation for bleeding, the associated increase in morbidity related to exposure of the patient to blood and blood products, and the expense associated with bleeding are significant. Postoperative bleeding is, in my experience, most frequently related to platelet dysfunction as the root cause. When I take patients back into the operating room for bleeding, I can almost always find one or more specific “bleeders,” but I am convinced that most of these sites of bleeding would have stopped if the patient’s coagulation mechanisms were intact. There have been many studies and strategies developed to prevent perioperative bleeding, including the use of aprotinin to reduce damage to platelets during the procedure, the preprocedural deposit of blood and platelets, the perioperative sequestration of blood and platelets, as well as the great care taken in the operating room, which is best described as the “art” of surgery. Despite all best efforts, bleeding occurs in association with cardiac surgery for a variety of reasons. The procedure is a major surgical insult. Large doses of heparin, which are imprecisely reversed with protamine after the procedure, are administered in order to prevent clotting in the pump. The heart-lung machine damages blood elements, in particular platelets. The postoperative platelet count, while it may be considered “adequate” in numbers, frequently is simply counting the presence of platelets shells that either do not work at all or do not work very well.