Systemic activation of tissue-factor dependent coagulation pathway in evolving acute respiratory distress syndrome in patients with trauma and sepsis

Background: Extravascular coagulation and fibrin deposition coupled with pe rturbations of intravascular coagulation occurs in association with acute r espiratory distress syndrome (ARDS), To evaluate the pathogenetic role of a n extrinsic coagulation pathway in the intravascular coagulation of ARDS pa tients and to explore the time course of the changes of tissue factor level s, platelet counts, and disseminated intravascular coagulation (DIC), we pe rformed a prospective cohort study, Methods: The study subjects consisted of 113 patients: 27 patients with ARD S, 31 patients at risk for but not developing the syndrome, and 55 patients without ARDS, According to the underlying disease, the patients were furth er subdivided into two groups: patients with trauma (n = 76) and patients w ith sepsis (n = 37), Tell normal healthy volunteers served as control subje cts. Plasma tissue factor antigen (tissue factor) levels and platelet count s were measured on the day of admission and on days 1 through 4 after admis sion. Simultaneously, the DIC scores were determined. Results: The values of tissue factor in the patients with ARDS were signifi cantly more elevated than those measured in the other two groups (p < 0.001 ) and control subjects (p < 0.001) on the day of admission. The values cont inued to be markedly high up to day 4 of admission. On the day of admission , the platelet counts in the ARDS patients showed significantly lower value s (p < 0.05) than those in the other two groups. The incidence of DIC and t he DIC scores in ARDS patients mere significantly higher than those in the other tyro groups. The tissue factor levels (r(s) = 0.428, p < 0.0001) and DIC scores (r(s) = 0.357, p < 0.0002) correlated significantly with Lung In jury Score. When the patients were subdivided into two subgroups, i.e., tra uma and sepsis, some differences of the tissue factor levels were noted bet ween the two groups. Conclusion: We demonstrated that tissue-factor dependent coagulation pathwa y of plasma is extensively activated in patients with ARDS, followed by int ravascular coagulation and platelet consumption. We further provide precise information on the time course of tissue factor levels and DIC in patients with ARDS and those at risk for developing this syndrome.