Normal prothrombinase activity, increased systemic thrombin activity, and lower antithrombin levels in patients with disseminated intravascular coagulation at an early phase of trauma: comparison with acute coagulopathy of trauma-shock.

BACKGROUND: We tested the hypotheses that an increase in systemic thrombin activity occurs in both disseminated intravascular coagulation (DIC) with the fibrinolytic phenotype and in acute coagulopathy of trauma shock (ACoTS), and that the patients diagnosed as having ACoTS overlap or are identical with those diagnosed as having DIC. METHODS: We made a prospective study of 57 trauma patients, including 30 patients with DIC and 27 patients without DIC. Patients with ACoTS, defined as a prothrombin time ratio >1.2, were also investigated. We included 12 healthy volunteers as controls. The levels of soluble fibrin, antithrombin, prothrombinase activity, soluble thrombomodulin, and markers of fibrin(ogen)olysis were measured on days 1 and 3 after the trauma. The systemic inflammatory response syndrome and the Sequential Organ Failure Assessment were scored to evaluate the extent of inflammation and organ dysfunction. RESULTS: Patients with DIC showed more systemic inflammation and greater Sequential Organ Failure Assessment scores and were transfused with more blood products than the patients without DIC. On day 1, normal prothrombinase activity, increased soluble fibrin, lesser levels of antithrombin, and increased soluble thrombomodulin were observed in patients with DIC in comparison with controls and non-DIC patients. These changes were more prominent in patients with DIC who met the overt criteria for DIC established by the International Society on Thrombosis and Haemostasis. Multiple regression analysis showed that antithrombin is an independent predictor of high soluble fibrin in DIC patients. Greater levels of fibrin and fibrinogen degradation products, D-dimer, and the fibrin and fibrinogen degradation products/D-dimer ratio indicated increased fibrin(ogen)olysis in DIC patients. Almost all ACoTS patients overlapped with the DIC patients. The changes in the measured variables in ACoTS patients coincided with those in DIC patients. CONCLUSION: Normal prothrombinase activity and insufficient control of coagulation give rise to systemic increase in thrombin generation and its activity in patients with DIC with the fibrinolytic phenotype at an early phase of trauma. The same is true in patients with ACoTS, and shutoff of thrombin generation was not observed.

Massive amounts of tissue factor induce fibrinogenolysis without tissue hypoperfusion in rats.

Trauma-induced tissue factor (TF) release into the systemic circulation is considered to play an important role in the development of disseminated intravascular coagulation (DIC) immediately after severe trauma. However, the relationship between TF and hyperfibrinolysis, especially fibrinogenolysis, has been unclear. A total of 18 rats were divided into three groups: (a) the control group was infused with normal saline; (b) the low-dose group was infused with 4 U/kg TF; and (c) the high-dose group was infused with 16 U/kg TF. Arterial blood was drawn immediately and 2 and 4 h after the start of TF infusion. At each sampling point, arterial blood gases, platelet counts, and coagulation variables were measured. The fibrinogen degradation products were evaluated by a Western blot analysis. Hypotension, hypoxemia, and lactic acidosis were not observed in any of the three groups. In proportion to the doses of TF, the platelet counts, coagulation, and fibrinolysis variables deteriorated in line with DIC. The α2-plasmin inhibitor levels significantly decreased in the high-dose group compared with the other groups. The amounts of fibrinogen degradation products increased in proportion to the doses of TF. The plasmin-α2-plasmin inhibitor complex level in the high-dose group increased more than that of the other groups. In conclusion, TF can induce DIC associated with fibrinolysis and fibrinogenolysis without tissue hypoperfusion. The decrease in the α2-plasmin inhibitor level and the significant increase in the plasmin level may be the two main factors underlying the pathogenesis of hyperfibrin(ogen)olysis after TF administration.