Venous Thrombosis and Pulmonary Embolism

Abstract

The data on the frequency of venous thrombosis and pulmonary embolism in inpatient material varies depending on the quality and extent of diagnostic measures available. On the basis of clinical investigation results the frequency of thrombosis in patients treated as inpatients, is quoted as up to 5%, pulmonary embolism between 1 and 2%, and the mortality after pulmonary embolism between 0.1 and 1%. In unselected post mortem material venous thromboses are quoted as 1.4–30%. In internal medicine post mortem material, 40–60% of venous thromboses were determined. In 15–20% of these patients with thromboses a pulmonary embolism was demonstrable. Again, of these only 11–15% had been diagnosed clinically, and were regarded as the cause of death in 3–8%. The accuracy of diagnosis of thrombosis and pulmonary embolism without technical equipment is in the most favorable case established as between 50 and 60%. However, it is usually lower (Fig. 1). Since phlebography, the ultrasound Doppler probe, and the radio-fibrinogen test were introduced, it has become clear that without prophylaxis thrombosis occurs in a considerably higher percentage of cases than formerly assumed (Table 2). About 90% of all clinically relevant thromboses occur in the venous region of the lower extremities and pelvis; 4% affect the upper limbs, and 2–4% affect the venous flow regions of other organs. Embolism of all grades of severity occurs with thromboses of the iliofemoral region in about 40% of cases, and in the lower leg in 11–30%.