A system of practical medicine. By American authors. Vol. 3

by Unknown

After section of the lungs there will always be found lesions of the bronchial mucous membrane, which presents evidences of catarrh extending as high as the trachea or larynx in some cases, but habitually growing more intense in the finer tubes, where the membrane is reddened and swollen. Frequently the infiltration extends throughout the structure of the bronchial walls, so that the tubes stand out prominently above the surface of the section. Delafield² has insisted with especial emphasis upon these alterations in the bronchial walls, and on the view that the inflammation extends from the bronchi, not to the group of air-vesicles into which they lead, but directly outward to the peribronchial zones of lung-tissue. In severe cases of longer standing the bronchial tubes often present in addition dilatations, either cylindrical or more rarely globular.

² "The Pathology of Broncho-pneumonia," Medical News, Nov. 15, 1884, p. 534.

The bronchi contain morbid secretions in the form of clear viscid mucus in the early stage, while later they are filled with creamy pus. In some cases there are also found small subpleural collections of more or less inspissated yellowish secretion contained in dilated alveoli or in small globular dilatations of terminal bronchioles. The most plausible explanation of their nature is, as suggested by Fauvel, that they are caused by the suction of particles of bronchial secretion into the alveoli in the forcible inspiratory effects which follow paroxysms of cough, and especially such paroxysms as occur when whooping cough is complicated with catarrhal pneumonia.

The lung-tissue itself exhibits, associated in varying degrees, congestion, oedema, emphysema, collapse, and pneumonic consolidation. The patches of simple collapse are to be easily recognized by their familiar appearance, being depressed below the surrounding tissue, bluish in color, non-crepitant and solid to the touch, and on section smooth, airless, firm, and not friable. They sink in water. As already stated, they can, when recent, be readily inflated, and thus restored to their normal condition. Such patches are most common at the postero-inferior parts of the lungs. They are mostly pyramidal in shape, and vary in size from a few lines to one or two inches in diameter, though in severe cases an entire lobe, or even an entire lung, may pass into this state of collapse. On the other hand, the areas of pneumonic consolidation appear as slightly prominent nodules, varying in size from that of a pea to that of a hazelnut, which may be distinctly felt with the finger, if occurring in the midst of a collapsed patch, by their elevation above the surrounding depressed tissue. They are usually scattered throughout both lungs, often with some symmetry of disposition, especially in the postero-inferior portions. The surrounding zone of tissue is more or less congested and oedematous, and when the nodules are closely adjacent they may become confluent, so that large portions of a lobe or an entire lobe may become infiltrated. Vigorous inflation will usually show in such cases, however, that the consolidation is not uniform or complete. Section of the lung will show that the most varied stages of the inflammatory process are represented in the different nodules; and this is a highly characteristic feature of the disease. The recent nodules are brownish-red or grayish-red, faintly granular, smooth, friable, and yield on scraping a small quantity of thick reddish secretion. Later they become reddish-gray and yellowish-gray in color, yield a thick, airless, milky substance, and finally grow more firm and dry: the inflammatory product undergoes fatty degeneration, is gradually removed by absorption or by expectoration, and the affected area of lung-tissue is slowly restored to its normal state. This is the course in favorable cases, while in those which run into a chronic form or which terminate fatally at an early period the lesions undergo various modifications. In some instances the inflammatory product undergoes more acute degeneration, with destruction of the pulmonary tissue in the affected area, and the subsequent formation of abscesses, which are not to be confounded with the minute aspiration-abscesses above described. I have notes of autopsies in which the lungs have presented every stage of the process of catarrhal pneumonia, from the nodules of incomplete consolidation to circumscribed abscesses. In other cases the thickening of the walls of the alveoli and of the bronchi, together with dilatation of the tubes, has become marked, and the interstitial changes in the zones of peribronchitic pneumonia extend and induce a slow process of fibroid thickening which results in that form of chronic pneumonia which has been called cirrhosis of the lung and fibroid phthisis. In still other cases the morbid products in the alveoli, with or without an antecedent process of suppuration, undergo caseation; and the presence of the degenerate cheesy foci, associated with alveolar and peribronchial thickening, may lead to catarrhal phthisis with or without true tuberculous formations.

The microscopic examination of the pneumonic nodules shows that the essential condition consists in a morbid accumulation within the alveoli, together with changes in the walls of the vesicles, which become infiltrated with cells in the same way as the bronchial walls. These changes become more marked after the disease has lasted some time. The epithelium lining the alveolar walls is the seat of cloudy swelling, becomes less closely attached, and undergoes proliferation, with the formation of large epithelial elements. The morbid product filling the alveoli is composed in varying proportions of these latter elements, of the richly cellular bronchial secretion which has been sucked in from the bronchioles, of leucocytes, and much more rarely of red blood-corpuscles which have escaped from the pulmonary capillaries, and finally of fibrillated exudation. In contrasting these minute appearances of catarrhal pneumonia with those of the croupous form it is to be noted that in the former the fibrinous element is not constant, or is at most scanty, and that the results of diapedesis, leucocytes, and especially red corpuscles, are much less prominent. At a later period of the process fatty infiltration and degeneration of the alveolar contents usually occur, which is the most favorable change, since it disposes toward evacuation with restitution of the lung to its normal state; but at times a larger proportion of pyoid cells appears, and the alveolar walls become involved and break down, so that small abscesses are formed, or, again, the contents may become inspissated and caseous, associated with nuclear growth in the walls of alveoli and bronchioles.

An account has thus been given of the lesions in fully-developed and disseminated catarrhal pneumonia; but I would again ask attention to the existence of a mild and circumscribed form of the disease, which rarely if ever causes death of itself. In these mild attacks, which occur frequently in adults, the part affected may be the base of the lung, but more commonly it is the root, the apex, or the lower anterior portion of the upper lobe. The anatomical condition is probably one of congestion, with extension of catarrhal inflammation into the alveoli without any preceding collapse, and with a varying degree of implication of the walls of the vesicles and of epithelial accumulation in the alveoli, though the process may not always go on to the production of fully-formed pneumonic nodules, such as above described. Yet it seems to me not only illogical, but eminently unsafe, to regard such cases otherwise than as catarrhal pneumonia, since while under proper treatment and in fairly healthy constitutions they uniformly terminate in resolution, on the other hand, they will, if neglected or if occurring in highly-vulnerable constitutions, run into a subacute form, with more extensive implication of the alveolar walls and peribronchial tissue, and will induce catarrhal phthisis. Allusion will be made again to these cases when speaking of the symptoms and diagnosis of catarrhal pneumonia.

In addition to the pulmonary lesions, the bronchial glands are, with rare exceptions, swollen and congested. In cases of longer standing foci of suppuration have been occasionally noted in them (Steiner), though cheesy nodules are more common. Acute miliary tuberculosis is a comparatively frequent complication. Oedema and congestion of the brain and meninges occur frequently, but are to be regarded as secondary lesions without special significance. It is probable, however, that more numerous examinations, in cases where death has been preceded by grave cerebral symptoms, would reveal the occasional occurrence of circumscribed areas of meningitis, with or without miliary tubercles. The liver is congested in acute cases, while in older ones there is apt to be fatty degeneration, which we have seen occur in irregularly distributed patches, imparting a peculiar mottled appearance to the organ. The kidneys also may be congested, but serious changes in the epithelium are rarely met with. Vastly more common are the lesions of catarrhal inflammation of the mucous membrane of the stomach and intestine. While in acute cases they may be superficial and slight, in those which have run a longer course Peyer's patches are prominent, and the solitary glands are enlarged, and not rarely oval ulcerations exist which may coalesce, so that I have seen quite extensive destruction of the mucous membrane of the colon simulating the effects of dysentery.

SYMPTOMS.—Before entering on a detailed description of the symptoms of catarrhal pneumonia it must be premised that this disease presents a far greater range in its degrees of severity than does croupous pneumonia. In this latter disease, although clinical evidence shows that its extent and course are less uniform than is often assumed, there is a remarkable uniformity in the stages through which the inflammatory exudation passes; but in catarrhal pneumonia, as in all forms of catarrhal disease, it is a marked characteristic that the process varies almost infinitely in different cases, both in the location, the extent, and the degree of development of the lesions. It is difficult to avoid the conclusion that a corresponding variety is presented by the symptoms, and that a complete clinical picture of catarrhal pneumonia must include cases of very mild character and of short duration, as well as those of a more severe and fully-developed type. I propose, therefore, to describe a mild form, an acute form of the ordinary well-developed disease, and also a subacute and chronic form.

The mild form is undoubtedly often overlooked, the attack being regarded merely as a feverish cold or as an ordinary bronchitis. Yet certain peculiarities in the symptoms, the course, and the tendencies of the cases I refer to serve to distinguish them, and enable them to be recognized as of more serious nature. More commonly the attacks occur in young adults whose systems are abnormally sensitive either from original weakness or in consequence of overwork, previous sickness, or the action of other depressing and exhausting causes. After some imprudent exposure there is a slight rigor, followed by headache, flushed, feverish feeling, soreness in the chest, aching in the limbs, and tight, dry, painful cough. A careful examination soon after the onset would reveal the familiar signs of a bronchial catarrh, though even now there might be noted a tendency for the affection to be less diffused than is usual in ordinary bronchitis.

If the patient is not prudent and solicitous about his health, no physician is summoned at once, and not rarely in the course of forty-eight or seventy-two hours the general symptoms have subsided so considerably that the patient feels able to move about, and may be led by pressure of business claims to resume his occupation. He finds himself so weak, however, and the cough is so much aggravated, that medical advice is sought. Distinct fever of remittent type is found, the morning temperature not exceeding 100° or 100½°, while in the evening it rises to 102° or 103°. There is a tendency to perspiration, especially on exertion, while exposure to a cool wind or draught causes a chilly feeling; exertion soon fatigues; sleep is restless; appetite is impaired; the tongue coated; the bowels irregular; and the urine high-colored. Cough is troublesome and somewhat painful, and the chest feels sore and weak. Physical examination will reveal, in the first place, bronchitic râles, dry and moist (sonorous, sibilant, and mucous), on both sides of the chest, though not rarely much more markedly on one side than on the other, or even limited to a portion of one side.