ObjectivesTo describe the time course and prognostic significance of tumor necrosis factor-alpha (TNF-alpha) levels and hemostatic abnormalities in clinical sepsis.DesignProspective, observational study with sequential measurements in an inception cohort.SettingAn emergency department in a university teaching hospital. Patients were followed up until they either left the hospital or died.PatientsDuring a 1-yr period, 43 adult patients were selected from all emergency department patients who met the established criteria for sepsis. Excluded were patients with either organ dysfunction or septic shock at the time of admission.InterventionsNone.Measurements and Main ResultsBlood samples were collected serially (day of admission and on days 3, 5, and 7) to determine TNF-alpha, platelet count, fibrinogen, factor VII, antithrombin III, tissue-type plasminogen activator activity, plasminogen activator inhibitor activity, plasminogen, and alpha 2-antiplasmin. Fibrinopeptide A was measured only on the day of admission. Data were analyzed to determine whether admission values or serially obtained values within 7 days were useful in predicting outcome. Thirteen patients died and 30 survived. On admission, assay values indicated that platelet count and antithrombin III were significantly lower than normal (as observed in 50 healthy adults). Fibrinogen, plasminogen activator inhibitor type 1, tissue-type plasminogen activator, fibrinopeptide A, and TNF-alpha were higher than normal, whereas concentrations of factor VII, plasminogen, and alpha 2-antiplasmin were in the normal range. No differences were detected in the admission values between survivors and nonsurvivors, except for antithrombin III. However, subsequent values of some variables demonstrated a difference between survivors and nonsurvivors. Survivors showed increasing platelet count and antithrombin III values compared with nonsurvivors, in whom the values remained low, with no significant changes during the study period. High TNF-alpha levels were found in both groups, but only survivors experienced progressive decrease during the observation period.ConclusionsEarly clinical sepsis is characterized by high plasma levels of TNF-alpha and by activation of the coagulation and fibrinolysis systems. Longitudinal analysis of some variables (antithrombin III, platelet count, and TNF-alpha) showed some differences with time between the survivor and nonsurvivor groups, but we feel that such differences were not large enough to be predictive in individual patients. (Crit Care Med 1999; 27:1303-1308)