41 British Medical Journal, March 27, 1869.
42 Clinique méd., t. iii. p. 715.
43 Such a case is reported by Playfair in Part V. of his Treatise on Midwifery, and is also recorded in Obst. Trans., vol. xii. p. 194.
Although the heart-beats are vigorous at first, they soon become weak, intermittent, and irregular. Similar characters may be noted in the pulse, which is very soon compressible, thready, and at times almost imperceptible. These latter conditions of the cardiac movements may exist from the beginning of the accidents, and may be accompanied by coldness of the extremities and chilly sensations (Cohn). Frequently we observe convulsive movements and foam at the mouth just before death. When these symptoms have been remarked, the question has been raised as to whether the patient was suffering from an epileptic seizure.44 The first impressive effects of pulmonary embolism undoubtedly attach themselves to the respiration and circulation. The nervous system is not always so visibly affected. Frequently the patients preserve complete mastery of their intelligence to the end, and cry out in no doubtful accents, "I am stifling! I am dying!" Occasionally they even point with their fingers to the exact seat of the sudden obstruction in the chest. In a case of Vidal45 the peculiar and painful sensations indicated by the patient in the precise location of the embolus had considerable diagnostic importance. This indication, however, is not always valuable, and may be misleading, as in the case reported by Ormerod, when the patient, a young girl, paraplegic, was attacked suddenly with intense feelings of suffocation and pointed to the throat as being the seat of the obstruction.46 Frequently these suddenly fatal cases occur in the course of an acute or chronic disorder, and usually the terrible phenomena manifest themselves after some movement or effort, as one makes in sitting up in bed or reaching for a desired object. Under these latter circumstances sudden pallor may overspread the features, the heart cease to beat, and the patient expire in a true syncopal attack, without any of the asphyxic appearance previously referred to. Usually, however, the need of air is most acutely felt, the muscles of the neck and thorax are violently contracted, whilst the patient suffers from intense anxiety and oppression. Meanwhile, air enters the lungs freely with each successive inspiration. Percussion and auscultation of the chest do not reveal any notable change in the pulmonary structure, and the peculiar asphyxia which is present results rather from the want of blood to be oxygenated than from the lack of air or sanguineous stagnation. Indeed, Lancereaux affirms that death in all cases of fatal pulmonary embolism follows upon these progressive asphyxic features. Never, according to him, does it occur from a real attack of syncope.47
44 Picot, Les grands Processus morbides, 1876.
45 Ball, Des Embolies pulmonaires, Observ. xxvii., Thèse, Paris, 1862.
46 London Med. Gazette, vol. ix. p. 788, quoted by Hayden, p. 1029.
47 "Comptes rendus de la Société de Biologie," 1861, Dict. de Méd. et de Chirurgie, vol. xxix. p. 365.
The immediate cause of death in these cases is differently regarded by eminent authorities. Virchow48 holds that the heart-beats suddenly stop and death is caused by syncope. Picot and Panum claim that inasmuch as the left heart does not receive any blood from the lungs, the brain cannot be supplied, and thus anæmia of the brain becomes the immediate source of a fatal termination. True it is that owing to the complete obstruction of the pulmonary trunk or its bifurcation no blood can reach the brain, but for a similar reason the coronary arteries cannot be supplied, and indeed the whole arterial system remains empty, whilst the surface of the body becomes livid, owing to marked venous distension. Paget holds to a conservative view, believing that death results at times from anæmia and on other occasions from syncope. It is the belief of the writer that most of the phenomena preceding death are in the majority of cases those of asphyxia, and he recognizes with Bertin49 and Lancereaux that deficient oxygenation of blood is, after all, the essential cause of death. In all cases of very rapid death, Lancereaux believes that the embolic clot must have originated in, and been transported from, one of the large veins of the lower extremities or the pelvis, and that the prolongation of clots formed elsewhere in the venous system, when broken off and carried in the blood-current, are insufficient by reason of their small size to block up completely the pulmonary artery.50
48 Gesamm., Abhandl., 1862, p. 316, quoted by Playfair.