Ancrod as prophylaxis or treatment for thromboembolism in patients with multiple trauma

To report the initial clinical experience with fibrinogen depletion using ancrod as prophylaxis and treatment for deep vein thrombosis and pulmonary embolism (DVT/PE) in patients with multiple trauma.

A series of cases, selected because of their extreme risk of DVT/PE or because of the appearance of thromboembolic complications despite prophylaxis using conventional methods.

University teaching hospital.

A referred sample comprising 30 patients with multiple blunt trauma. The mean injury severity score was 30. Most cases involved a combination of lower extremity, pelvic and chest injuries.

Fibrinogen was slowly depleted over 24 to 36 hours and the concentration maintained at 0.2 to 0.5 g/L thereafter. Ancrod was continued prophylactically (22 patients) or for established DVT/PE (8 patients) until the patients were mobilized or until there was no longer a contraindication to heparin, or until treatment with warfarin became practical.

Monitoring for DVT by duplex ultrasonography or iodine-125-labelled-fibrinogen scanning, whichever could be applied.

Twenty patients were treated with ancrod for prophylaxis from the outset because it offered theoretic and practical benefits over other methods. No patient treated with ancrod for prophylaxis suffered a clinically significant DVT/PE. Patients in whom heparin prophylaxis failed and who experienced thromboembolic complications were effectively managed with ancrod. There were no deaths and no bleeding complications specifically due to the therapy.

Slow depletion of fibrinogen with ancrod may provide a safe and effective means to prevent DVT/PE in multiple trauma patients or to treat DVT/PE when the risk of bleeding from heparin is great. This initial experience should be evaluated by a randomized controlled trial.