OBJECTIVES: To investigate the time course and the relation to prognosis of coagulation and fibrinolytic abnormalities in patients with septic shock. PATIENTS AND METHODS: Forty-eight consecutive patients admitted to the medical ICU with the diagnosis of septic shock (diagnosed by defined criteria) were studied. Mortality was 25 of 48. Mean age was 57 +/- 7.3 years. Blood samples were obtained on days 1, 4, and 7 after hospital admission to measure tissue-type plasminogen activator antigen (t-PA), urokinase-type plasminogen activator (u-PA), plasminogen activator inhibitor antigen (PAI-1), plasminogen, alpha 2-antiplasmin, fibrinogen, antithrombin III, protein C, protein S, thrombin-antithrombin complexes (TAT), D-dimer, and von Willebrand factor-related antigen (vWF:Ag). RESULTS: All patients showed marked abnormalities in both the coagulation and fibrinolytic systems. There were signs of coagulation activation and elevation of both activators and inhibitors of fibrinolysis. Nonsurvivors showed lower levels of protein C and antithrombin III and higher concentration of TAT than survivors. While both t-PA and PAI-1 concentrations were high in survivors and nonsurvivors, only survivors showed a progressive normalization of both parameters during the study period. Low plasminogen levels and plasminogen/alpha 2-antiplasmin ratio were found in both groups, presenting a trend toward normalization only in survivors. The differences reported were not apparent at the time of hospital admission. CONCLUSIONS: Septic shock is characterized by coagulation activation and fibrinolysis activation and inhibition. Nonsurvivors present a particular hemostatic profile characterized by a more marked activation of coagulation and a more intense inhibition of fibrinolysis. None of the abnormalities studied was significantly different between survivors and nonsurvivors at the time of hospital admission. In the presence of fibrin formation, nonsurvivors present a maintained imbalance in the fibrinolytic response determined by higher PAI-1 plasma concentration, probably contributing to their poor outcome.