Postoperative thromboembolism and risk factors in elective hip surgery

The incidence of pulmonary embolism determined by perfusion - ventilation lung scintigraphy was 19% in 108 consecutive patients undergoing elective hip operations. Twelve patients had clinical symptoms. The sensitivity of clinical symptoms was 30 and the specificity 93%. Warfarin was used as prophylactic anticoagulant. The incidence of deep vein thrombosis examined by contrast venography was 43%. Only one patient developed femoral vein thrombosis propagating from the calf region. From the clinical risk factors, overweight had a statistically significant relationship to thromboembolism (p = 0.005). Age over 60 years was positively associated but the difference was not significant. When operation time exceeded 150 min the risk increased significantly (p less than 0.01). A large volume of blood loss at operation showed an increased but statistically insignificant trend towards thromboembolism. There were no fatal emboli. Although prophylactic warfarin treatment is not able to prevent the development of thromboembolism, it probably reduces the incidence of fatal pulmonary emboli. Of clinical and operative risk factors overweight and increasing operation time seem to have the strongest relationship to thromboembolism.