Transfusion of Blood Products Affects Outcome in Cardiac Surgery

Abstract

There remains controversy as to when patients undergoing cardiac surgery should receive a transfusion and whether a low hematocrit and its treatment with a transfusion of red cells influences outcome. The data related to this controversy are reviewed. Although the risk of known viral transmission is currently low, stored red cells do not function normally, and each unit contains activated inflammatory cells and mediators. These changes cause limited oxygen release, impaired microcirculatory flow, and immune suppression. A number of studies have observed decreased survival associated with transfusions in trauma, coronary artery bypass grafting, and intensive care unit patients. Studies that show an adverse outcome associated with low hematocrit are not definitive, because they fail to distinguish between the impact of low hematocrit per se and the possible adverse effects of transfusion, for what the low hematocrit may simply be a surrogate. The observation that a low hematocrit is associated with an adverse outcome does not necessarily prove that "treatment" of the anemia with a red cell transfusion will improve the outcome. Stored platelets contain a highly activated mixture of platelets with storage lesions and inflammatory mediators. Two retrospective post hoc multifactorial analyses suggest that platelet transfusions are associated with substantial increased morbidity and mortality. Clearly, large prospective studies are required to define the proper trigger for blood product transfusion to balance the adverse effects of anemia and platelet deficiency or dysfunction with the adverse effects of transfusion of blood products on morbidity and mortality associated with cardiac surgery and anesthesia.

Audit of factor VIIa for bleeding resistant to conventional therapy following complex cardiac surgery

“…Further, we had growing concerns about the limitations and side effects of conventional therapy. 11,12 Therefore, with the approval of the Austin Health Drugs and Therapeutics Committee, we developed a guideline for the use of rFVIIa in cardiac surgery (Table III) which was applied to the last 25 patients in this series. Our guideline has much in common with a recent Israeli guideline for rFVIIa use in uncontrolled bleeding, including trauma.…”

“…11,22 One study of 50 medical and surgical patients found that rFVIIa was more effective in mild to moderate coagulopathy than severe coagulopathy. 23 If used, rFVIIa should be administered in a timely manner, not as a "last ditch option".…”

Risks Associated With the Transfusion of Various Blood Products in Aortic Valve Replacement

“…Blood transfusions after CABG have commonly been associated with increased long-term mortality (1)(2)(3)(4)(5)(6)(7)(8) as has CABG combined with AVR (9). We reached different results in a CABG population, where we extended the number of risk-factors entered in the survival analysis and did not find any association between transfusion of RBC and long-term survival in patients only undergoing CABG (10).…”

Perioperative Administration of Fibrinogen is Associated with Increased Risk of Postoperative Thromboembolic Complications after Cardiac Surgery

“…Severe bleeding during and after cardiac surgery is a serious and relatively common complication associated with increased morbidity and mortality [1][2][3]. The risk of postoperative bleeding increases with age and prolonged cardiopulmonary bypass (CPB) [4][5].…”