Blood clotting and fibrinolytic activities were studied in cases of severe trauma, general surgical operations and extracorporeal circulation. Among those cases, changes in fibrinolytic and clotting activities were smallest in general surgical cases. In cases of severe trauma and extracorporeal circulation, especially in cases of prolonged perfusion reductions in platelet counts, and fibrinogen and other clotting factor levels were observed. In most cases of extracorporeal circulation, prolongation of r values in thrombelastogram and reduciton in factor V and factor II (prothrombin) level were observed. As far as the fibrinolytic activities were concerned, slight changes. were observed in most cases.
However, since changes in clotting activities were also observed in cases with normal fibrinolytic activities, it is not considered that the changes in clotting activities were caused by the abnormal fibrinolytic system. In cases of extracorporeal circulation, changes in firbinolytic activities were observed to be more likely happened, when the bubble oxygenators were employed. In cases of severe trauma, it was observed that the more severe the trauma was, the more prominent were the changes in fibrinolytic system.
