Acute pulmonary embolism: II. Clinical

Pulmonary embolism is the commonest lethal pulmonary disease in the United States and is a contributing cause to the deaths of many additional patients. Yet its clinical recognition remains difficult and often impossible. This is so because the lung has no pain fibers, and has a large vascular reserve, and because clinical manifestations, when present, are variable, complex, and not infrequently completely obscured by the underlying disorder. It is unlikely that additional clinical observations will significantly increase accuracy of diagnosis. Increased accuracy of diagnosis will depend upon the development of new screening tests and the fullest use of those presently available. These latter are the triad of increased serum lactic dehydrogenase and bilirubin with a normal serum glutamic oxalacetic transaminase, frequently repeated electrocardiograms and roentgenograms of the chest, lung scanning, and (hopefully) ultrasound. There would appear to be no reason to use screening tests in the vast majority of instances of pulmonary embolism which are clinically silent and free of clinical precursors, and yet these emboli may be forerunners of an additional pulmonary embolism for which treatment is still not satisfactory. Hence the best hope for reducing the morbidity and mortality from pulmonary emboli lies not in treatment but in prevention.