Dissemenated Intravascular Coagulation in Patients with Septic Shock: Impact of Coagulation Markers on Prediction of the Mortality

Background: Patients with severe sepsis usually present with a generalized activation of the innate immune response that triggers coagulation and inhibits fibrinolysis. Haemostatic abnormalities associated with severe sepsis may vary from subtle laboratory evidence of coagulation activation to clinically overt, severe disseminated intravascular coagulation (DIC). Clinically, severe DIC may contribute to multiple organ dysfunctions by microvascular thrombotic complications. Despite its obvious effects on microcirculatory conditions, the impact of these modifications on mortality prediction is not clear. The International Society on Thrombosis and Haemostasis (ISTH) has proposed a diagnostic scoring algorithm for overt DIC based on routine laboratory test. These templates have been validated prospectively in independent patient populations, both as a tool for defining diagnostic scores for DIC, and as a method to demonstrate prognostic associations for DIC scores with mortality risk. We aimed to study, in patients entering an intensive care unit with septic shock, prognosis performances of two DIC scores D-Dimers (D-Di) and soluble fibrin monomers (SFMC) calculated with an informative cut-off of D-Di or SFMC.

Methods: One hundred fifty-eight consecutive patients with septic shock entering our institutions ICU were investigated on the first day of admission, and two DIC scores (D-Di and SFMC) were registered at the admission and during the first five days. We evaluated the blood cell count and haemostasis-related parameters on the initial blood sample: aPTT ratio, TP ratio, fibrinogen Fg; antithrombin; factor VII, X, II, II; D-Di and SFMC. The diagnosis of overt-DIC was performed according to the recommendations of the ISTH. We used a test trend (Cochran-Armitage) on mortality to analyze prognostic associations for the two DIC scores with mortality risk, according different D-Di and SFMC cut-off.

Results: Eighteen patients died on the first day of inclusion (mortality 11.5%), 35 patients during the first week (22.2%). Sixty-one patients were transfused (38.6%). No AT concentrates were given, Fg concentrates were used for two patients and recombinant activated human protein C (Xigris; Eli Lilly and Co., Indianapolis, USA) was given to 18 patients after the initial blood sampling (11.4%; six of them died). A trend on mortality was detected (p<0.05) according to the two DIC scores (D-Di or SFMC) with a cut-off equal to 2 and to 10 for D-Di and SFMC respectively. We identified with this cut-off that all the patients with a DIC score (D-Di) ≤ 2 (n=19/19) survived [negative predictive value (NVP) equal to 100% (_95%CI: [82.4–100.0]. Similarly, with a SFMC cutoff of 10, 71/84 patients with a DIC score (SFMC) ≤ 2 survived corresponding to a NVP 84.5 % (_95%CI: [75.0–91.5].

Conclusion: This single-institution study demonstrates that the mortality of patients with septic shock is related to DIC scores (D-Di and SFMC). We proposed a significant cut-off for D-Di and SFMC scores that allowed identifying with an excellent NVP patients with a low risk of death.