Prevention of fatal pulmonary embolism with warfarin after total hip replacement.

We studied retrospectively the efficacy of low-dose warfarin for the prevention of fatal pulmonary embolism in 1140 patients (1280 hips) undergoing total hip replacement between 1972 and 1989. The first dose, 10-20 mg, was given the night before operation and the regime was continued for 2 weeks after the procedure. Anticoagulation was aimed at achieving a therapeutic level in 4 to 5 days. All the patients were followed for 3 months. Seven died during this period and autopsy showed that 2 (0.16%) died from pulmonary embolism, one at 3 days and the other 10 days after operation. Pulmonary embolism causing symptoms, but which was not fatal, occurred in 32 patients (2.5%). Symptomatic deep vein thrombosis was present in 45 patients (3.5%). There were 14 (1.1%) massive postoperative haematoma, and 7 needed operative treatment. Low-dose warfarin can be recommended as a safe and efficient method of achieving an acceptably low incidence of postoperative thrombo-embolic complications after total hip replacement.