Effect of dextran on fibrinolysis inhibition activity in the blood after major surgery.

Patients undergoing total hip replacement surgery were given 500 ml of 6% dextran 70 or 5% albumin by intravenous infusion on the third postoperative day when the post-traumatic fibrinolysis inhibition has reached its maximum. The large increase in the fibrinolysis inhibition activity measured by a clot-lysis system was counteracted by the infusion of dextran, whereas the albumin infusion had no such effect. The plasma concentration of antiplasmin (chromogenic substrate assay) and the immunologically determined plasma levels of the primary fibrinolysis inhibitor (alpha2-antiplasmin), alpha2-macroglobulin, alpha2-antitrypsin and plasminogen were not changed after the infusion of dextran. It is hypothesized that dextran exerts its effects partly by interfering with the interaction between the primary fibrinolysis inhibitor, fibrin and plasmin(ogen) and by enhancing the activation rate of plasminogen. This observed effect of dextran may be of importance in the prevention of deep venous thrombosis and pulmonary embolic complications, as well as pulmonary microembolism.