Two patients are reported in whom fatal alveolar pulmonary haemorrhage occurred after pulmonary embolectomy. Possible causes and methods of prevention are discussed.Pulmonary haemorrhage after embolic occlusion of a pulmonary artery usually follows the infarction of lung parenchyma. This complication is particularly prevalent in patients suffering from chronic congestive cardiac failure. The usual finding in such cases is obstruction of a segmental or smaller artery with infarction of the parenchyma supplied by it. The haemorrhage itself is usually slight and unimportant as regards eventual prognosis.Parenchymal bleeding following obstruction of the main branches of the pulmonary artery, without overt evidence of infarction, and severe enough to cause death at a time when the obstructing embolus has been removed, is a rare eventThe purpose of this communication is to describe two patients in whom fatal pulmonary haemorrhage occurred following the removal of the obstructing clot. This complication of pulmonary embolectomy is relevant, as several nonoperative methods of treating acute pulmonary embolism have recently been introduced. CASE HISTORIES CASE 1 Mrs. R. S., aged 55 years, had a right partial nephrectomy for renal calculus. There was no previous history of cardiac disease. On the fifth postoperative day thrombophlebitis occurred in the left leg. A few hours later chest pain, dyspnoea, and a fall in blood pressure occurred. Heparin therapy was started, but 22 hours later there was a further episode with dyspnoea, cyanosis, and hypotension. An electrocardiogram showed acute right heart strain ( Fig. 1). A pulmonary angiogram (Fig. 2) showed a complete blockage of the right main pulmonary artery and a further block in the artery to the left lower lobe.In view of continued deterioration despite routine medical treatment, emergency pulmonary embolectomy with cardiopulmonary bypass was carried out 34 hours after the initial embolus. A large coiled clot was removed from the right main pulmonary artery, and smaller fragments from the left lower lobar artery. The total time on full bypass was 20 mirnutes. While weaning off bypass there was a massive exudation of haemorrhagic pulmonary oedema fluid from the endoctracheal tube. This rapidly resembled pure blood and appeared to come from the right lung, which looked congested and infarcted. The left lung became flooded, despite attempts to exclude the right with a Carlen's tube. It proved impossible to oxygenate the arterial blood, and the patient died from cardiac arrest.Necropsy showed a healthy heart and coronary vessels. There was antemortem thrombus in the left femoral vein. Fluid blood was present in the right bronchial tree. The right lung was soft and haemorrhagic with antemortem thrombus in the smallest arteries, but the major pulmonary vessels were normal. Histological examination confirmed infarction of the parenchyma (Fig. 3). An incidental finding was a recent right adrenal haemorrhage (Fox, 1969). CASE 2 Mr. J. W., aged 53 years, had suffered from myelo...
