Evaluation of postoperative blood coagulation changes in elderly patients undergoing major surgery

18 elderly patients submitted to major surgery for malignancies or other disease were studied to assess the relationship between changes of blood coagulation factors and inhibitors in the early post-operative period and the appearance of lower limb deep vein thrombosis. A decrease in serum antithrombin III (AT III) Protein C antigen (PC: Ag) and Plasminogen activity (PLG) levels from the second to the fourth postoperative day, together with a simultaneous increase in serum fibrinogen (FG) and von Willebrand Factor (vWF:Ag) antigen levels was observed. In 8 patients, PC:Ag levels dropped below the limit considered at risk to develop DVT (less than 60 U/dl). A patient with the lowest PC:Ag levels had deep vein thrombosis From the analysis of data it was concluded that in the postoperative period, blood coagulation changes occur in elderly patients, predisposing to the risk of deep vein thrombosis.