[Antithrombin III and fibrinogen after surgical interventions on the abdomen and heart]

We have explored the changes of plasma concentrations of antithrombin III and fibrinogen in patients recovering from major abdominal and cardiac surgery. In one group of patients subjected to major abdominal surgery we detected a statistically significant reduction of antithrombin III in the second and third postoperative day, followed by return to normal values in the fourth or fifth day. Fibrinogen, instead, increased to as much as 180% of the preoperative value in the first four postoperative days and reverted slowly to preoperative values between the fourth and the eighth day. In another group of patients subjected to cardiac surgery procedures utilizing the heart-lung machine, however, we found no significant reductions of antithrombin III in the early postoperative period. These results suggest the possible influence of local tissue factors affecting the plasma levels of antithrombin III differently in the two types of surgery under discussion. The patients subjected to extracorporeal circulation, on the other hand, showed a depletion of plasma fibrinogen down to less than 30 or 40% of preoperative values. This may reflect activation of coagulation processes and the considerable sequestration of fibrin at some interfaces of the heart-lung machine.