[Prevention of thromboembolism with low-dose heparin].

With an amidolytic assay plasma heparin activity is measured in patients undergoing elective abdominal surgery and general surgery under LDH-prophylaxis. The data obtained suggest that the response of the hemostatic system to 3 X 5000 U. heparin is individual and unpredictable. In 82 patients undergoing hip fracture surgery it could be demonstrated that there is a correlation between anticoagulant heparin activity and the incidence of DVT.