Strategies to diagnosis and screening of deep venous thrombosis and pulmonary embolism

The clinical diagnosis of venous thrombosis or pulmonary embolism is unreliable and must be confirmed by objective methods. The available objective diagnostic tests which have been evaluated for deep vein thrombosis and shown to be of value are venography, IPG, and (125I)-fibrinogen leg scanning. All these methods have certain disadvantages, but the potential advantages of accurate diagnosis using a combination of non-invasive tests as an alternative to venography are considerable. This approach is cost-effective, because it avoids unnecessary hospital admissions and reserves anticoagulant treatment for those in whom diagnosis of deep venous thrombosis is confirmed. Non-invasive techniques can also be used to screen high risk surgical patients for whom no inexpensive, effective, safe form of prophylaxis is available. The correct diagnostic approach in suspected pulmonary embolism remains to be established. The initial screening by perfusion lung scan with ventilation studies, followed by either the demonstration of pulmonary emboli with angiography, or the demonstration of peripheral deep venous thrombosis, is considered to be the safest approach