Procoagulant activity in patients with isolated severe head trauma

Objective: To determine the degree of regional and systemic coagulation activation soon after isolated severe head injury. Design: Prospective, controlled clinical study. Setting: The emergency room and intensive care unit (ICU) of a trauma center in a university hospital serving a population of 5 million people. Patients: Twenty four trauma victims: 20 patients with isolated severe head injury (head trauma group, Glasgow Coma Score of less than or equal to 8) and four patients with isolated bone fracture (control group). Interventions: Insertion of central venous, i.e, superior caval vein, jugular bulb, and arterial catheters for blood sampling. Measurements and Main Results: Central venous (i.e., superior caval vein) global coagulation variables (i.e., prothrombin time, activated partial thromboplastin time, fibrinogen concentration, antithrombin III activity, and platelet count) and central venous and jugular bulb activation coagulation and fibrinolysis variables (i.e., prothrombin fragment F1+2, thrombin-antithrombin III complex, soluble fibrin, and D-dimer concentration) were measured soon after trauma (<6 hrs) and 3 hrs later. When compared with the control group patients, upon ICU admission, fibrinogen concentration (p < .005) and platelet count (p < .025) were significantly decreased in the head trauma group. Thrombin-antithrombin III complex (p < .025), prothrombin fragment F1+2 (p < .025), and D-dimer (p < .005) concentrations measured at the time of ICU admission were significantly higher in the head trauma group than in the control group. Only in the head trauma group were soluble fibrin concentrations increased above the normal range; thrombin-antithrombin III complex and the prothrombin fragment F1+2 were found to be significantly higher in cerebrovenous blood than in central venous blood (p<.025). There was no cerebrocentral venous difference in the concentrations of soluble fibrin or D-dimer in either group. Conclusions: Within 6 hrs after severe isolated head trauma, systemic procoagulant overflow from the traumatized cerebral microvasculature proceeds to the thrombin level and is then inhibited by antithrombin III. Regional and systemic hypercoagulability and increased D-dimer concentrations appear to be common among head trauma patients. Increased procoagulant and consecutive fibrinolytic turnover may, therefore, spark disseminated intravascular coagulation in this patient group.