Effects of coagulation factor deficiency on plasma coagulation kinetics determined via thrombelastography®: Critical roles of fibrinogen and factors II, VII, X and XII

Background: Thrombelastography (TEG®) is used to assess coagulopathy. However, a comprehensive characterization of the effects of specific coagulation factor deficiencies and mode of activation on TEG® data does not exist. Methods: Thrombelastography® was performed for 15min with control plasma and plasmas deficient (<1% activity) in Factors II, V, VII, VIII, IX, X, XI, XII, or XIII activated with celite (0.28 mg ml^-1) or tissue factor (TF, 0.1%) (n = 6 per condition). Additional fibrinogen concentration activity (75-345 mg dl^-1) and Factor II, VII, X and XII activity-response relationships (1%, 6.25%, 12.5%, 25%, 50% and 100% activity) were obtained (n = 8 per condition). Thrombelastography® parameters included reaction time (R), angle (α), and clot strength (A, amplitude; G, elastic modulus). Results: Celite activation of FXII-deficient plasma, TF activation of FVII-deficient and FX-deficient plasma, and celite or TF activation of FII-deficient plasma resulted in an almost undetectable clot. Compared to control values, celite activation of plasmas deficient in FXI, FIX and FVIII resulted in prolonged R and decreased α values, whereas TF activation resulted in decreased α values. Celite and TF activation of FV-deficient plasma resulted in prolonged R and decreased α values, whereas FXIII-deficient plasma had decreased α, A and G-values compared to control values. Conclusions: The fundamental finding of this study is that coagulation factor deficiencies affect TEG® parameters in both a factor-dependent and activation-dependent fashion. Utilizing both celite and TF activation improves the diagnostic power of TEG®. Based on such TEG® data, more targeted administration of blood products could potentially help improve perioperative hemostatic outcomes.