PULMONARY EMBOLISM

Abstract

1. 1. Experimentally, two types of fatal pulmonary embolism have been produced: one which plugs the terminal vascular bed and is characterized by cyanosis and dyspnea; and the other which represents an obstruction to the main pulmonary artery and exhibits a syncopal attack with pallor and fall in blood pressure. 2. 2. The possible mechanisms of death have been analyzed. Atropine protects a large percentage of animals dying from the massive type of embolism, and so does papaverine. Oxygen is helpful in the peripheral type of embolism. 3. 3. Electrocardiograms taken in dogs before and after the production of a massive pulmonary embolism present a picture resembling a serious interference with coronary flow. The possible causes of these findings are analyzed. 4. 4. The clinical application of these findings is discussed. In our series of 100 cases of pulmonary embolism, 87 died and 13 survived. Of the fatal cases, less than 10 per cent died within the first ten minutes, thus allowing time for emergency measures. 5. 5. On the basis of the experimental findings, a combination of atropine and papaverine is advocated to counteract the radiation of autonomic reflexes, which originate in the affected lung. Oxygen is obviously useful in the peripheral type of embolism, in which vasomotor collapse is absent but cyanosis predominates. 6. 6. A few other drugs commonly employed, such as epinephrine, neo-synephrine, digitalis, and strophanthin, are discussed but not recommended. 7. 7. As manifest thrombosis of the veins of the pelvis and lower extremities is comparatively rarely encountered in patients with massive pulmonary embolism and heparinization of a large number of post-operative cases is yet impossible, the early and active interference with the described autonomic reflexes occasionally may be the only available life-saving measure.