Effects of recombinant human activated protein C on the coagulation system: a study with rotational thromboelastometry

Background: Recombinant human activated protein C (rhAPC) is an anticoagulant that can be used for treatment of patients with severe sepsis. The use of rhAPC is accompanied by an increased risk of severe bleeding. Rotational thromboelastometry is a method for measuring the status of the coagulation. The aim of the study was to investigate whether rotational thromboelastometry could be used for monitoring the effects of rhAPC on the coagulation. Methods: Whole blood was mixed in vitro with concentrations of rhAPC ranging from 0 to 75 ng/ml and analysed with rotational thromboelastometry. Results: The parameter Coagulation Time was significantly prolonged by increasing the concentrations of rhAPC ( P =0.002). Other parameters were not significantly affected. Conclusion: rhAPC dose dependently affects the early humoral parts of the coagulation, while platelet function and fibrinogen to fibrin conversion seem virtually unaffected.