Ex vivo thrombin generation patterns in septic patients with and without disseminated intravascular coagulation

The thrombin generation test (TGT) describes the ability of the plasma to generate thrombin. Its usefulness in septic patients has yet to be assessed.

Patients admitted for severe sepsis in a medical intensive care unit were sampled for TGT on day 0, 3, 6, and 10. TGT data were compared to "classical" hemostastic tests and to outcome parameters, notably disseminated intravascular coagulation (DIC) according to International Society for Thrombosis and Hemostasis criteria as well as survival.

A total of 102 patients were recruited of whom 11 received therapeutic anticoagulation and showed profoundly-altered TGT parameters. In comparison to healthy subjects, the 67 septic patients without DIC exhibited longer Lag times, higher Rate Indices, no change in peak or amount of thrombin generated, although the return to baseline was prolonged. In the 24 DIC patients, Lag time and Rate Index did not differ from healthy subjects (Rate Index being significantly lower than in Sepsis patients). The decreases in peak and amount of thrombin generated were not significant. Return to baseline was prolonged comparatively to Sepsis patients. Due to a large overlap of TGT values between groups, the ability of TGT parameters to diagnose DIC or predict survival was respectively poor or absent.

The thrombin Generation Test displayed particular patterns in septic patients and in septic DIC patients. The wide overlap between patients in TGT values prevents the usefulness of this test in clinical practice.