LAUSR

TRADITIONAL MANAGEMENT of post-bypass coagulopathy often relies on the transfusion of fresh frozen plasma and platelets in order to achieve acceptable hemostasis. However, this can often be detrimental to both cardiac function and hemodynamic stability due to the volume overload from excessive transfusion. Furthermore, an increase in red blood cell transfusion is common due to dilution. The rising use of factor concentrates for factor repletion has aided in providing therapy that can be given in much smaller volumes, along with more concentrated amounts of coagulation factors. These concentrates include recombinant activated Factor VII (rFVIIa), fibrinogen concentrates, and prothrombin complex concentrates (PCC). Certainly, the off-label use of these concentrates in cardiac surgery has demonstrated sufficient clinical benefits leading to their inclusion in blood management guidelines; however, their use does not come without safety concerns and thrombosis risk. Additionally, each of these concentrates has been well studied against standard transfusion approaches described above, but there are far fewer direct comparisons of the effectiveness of factor concentrates when compared with other factor concentrates in the cardiac surgery setting. As we continue to explore these therapies for optimal dosing, timing of administration, and safety profiles, we must keep in mind that each of these targetspecific agents works differently with different intended goals, and therefore, any direct comparisons of factor concentrates may not be as straightforward as we would like. Initial comparisons of one factor concentrate to another actually date back to more than a decade ago, although studies did not involve cardiac surgical patients directly. In the setting of sustained anticoagulation (ie, vitamin K antagonist), 4-factor PCC (Factors II, VII, IX, X) compared to rFVIIa, an animal model demonstrated that PCC was more effective in restoring hemostatic function. Interestingly, a comparison of 3-factor PCC (Factors II, IX, X) and low-dose rFVIIa in patients requiring emergent warfarin reversal revealed that 1.0 to 1.2 mg of rFVIIa was more effective at achieving an international normalized ratio (INR) less than 1.5 when compared with 3-factor PCC (average dose 20 U/kg). Next, a direct comparison of 4-factor PCC to 3-factor PCC in an