Evaluation of the Thrombelastograph Targeted Coagulation Assessment

Abstract

Extracorporeal circulation predisposes patients to hemorrhagic risk which may increase both homologous transfusion requirements and the need for pharmacological intervention. The aim of this study was to evaluate the efficacy of a new diagnostic coagulation assay utilizing the thrombelastograph (TEG). Following Institutional Review Board approval, blood was drawn from healthy, non-medicated volunteers and four in vitro coagulopathic conditions were created, which included: hyperfibrinolysis (100% lysis), hypofibrinogenemia (<50 mg/dl), and both qualitative (1000 ug/ml nitroglycerin) and quantitative (<50 K/mm3) platelet abnormalities. Each of these four blood samples was then divided among four vials that contained known quantities of either: aminocaproic acid, fresh frozen plasma (FFP), platelet concentrate, or heparinase, and TEG profiles were completed. Twenty-one samples were evaluated and the following results were obtained. Hyperfibrinolysis- 100% correction of fibrinolytic potential in the aminocaproic acid vial, but none in the other vials. Qualitative platelet dysfunction- significantly improved time to coagulation in the platelet vial but not in the FFP, heparinase or aminocaproic acid vials. Quantitative platelet dysfunction- no significant difference observed between any vials. Hypofibrinogenemia- significant improvement in the TEG index in the FFP vial (-2.7 ± 0.5) when compared to the aminocaproic acid ( -8.6 ± 2.5, p<.001), platelet (-6.5 ± 0.5, p<.01) and heparinase (-8.8 ± 2.5, p<.001) vials. We conclude that this coagulation assessment assay may help in identifying the specific source of bleeding during surgeries where hyperfibrinolysis, hypofibrinogenemia, or qualitative platelet dysfunctions are present.