A review of transfusion risks and optimal management of perioperative bleeding with cardiac surgery

Although the incidence and pathophysiology of many transfusion-related complications are well documented, unresolved questions persist. Transfusion medicine initiatives are being implemented to reduce complications (e.g., chemical inactivation of pathogens, WBC depletion); however, the literature is describing an increased incidence of other potential transfusion-related problems (e.g., TRALI, immune-modulation, MOSF), in addition to identifying new potential pathogens (e.g., variant CJD, SARS, avian influenza viruses). Furthermore, blood shortages may limit our ability to adequately manage our anemic and bleeding patients. Excessive bleeding after cardiac surgery can result in increased morbidity and mortality due to transfusion- and hypoperfusion-related complications, as well as injury to critical organ systems. Use of POC tests of hemostatic function can facilitate the optimal management of excessive bleeding and reduce transfusion. Accordingly, POC tests that assess PLT function may also identify patients at risk for acquired, PLT-related bleeding that may be attenuated with pharmacologic agents. In addition, rapid acquisition of coagulation data can also allow physicians to better differentiate between microvascular bleeding and surgical bleeding. An ideal algorithm would encompass test systems that evaluate heparin activity, fibrinolysis, coagulation factor levels, and qualitative and quantitative PLT abnormalities. rFVIIa has the potential to reduce transfusions and transfusion-related sequelae and may be life-saving in certain circumstances. Randomized, controlled trials are warranted, however, to assess both the efficacy and, more importantly, the safety of this intervention in cardiac surgical patients before its use as a first-line therapy for bleeding or for bleeding prophylaxis. We must continue to carefully investigate the role of new interventions, because the ability to reduce use of blood products to decrease operative time and/or reexploration rates has important implications for disease prevention, overall patient safety, blood inventory, and associated costs, as well as overall health care costs.