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

by Unknown

2. Chronic Lobular Emphysema.

In many cases emphysema is confined to a limited number of lobules, especially at the apices, the anterior borders, or about the base of the lung; and being gradual in development and permanent in duration, it is then termed chronic lobular emphysema. This is the form frequently met with in the different varieties of pulmonary phthisis, in which its development seems supplementary to the incapacitation of other portions of the lung. The lobules nearest to the surface of the lung or immediately beneath the pleura are found to be most distended, so that they often project beyond the adjacent surface.

Chronic lobular emphysema is chiefly of interest in connection with the other pulmonary diseases which give rise to it. The mechanism of its production is like that of acute lobular emphysema, but the diseases occasioning it being chronic the emphysema to which they give rise is equally permanent. At the apex of the lung, its most common situation, it is very often associated with tubercle in a calcareous state. The changes accompanying this deposit of tubercle favor the loss of elasticity in the vesicles of the apex, and the violent expiratory efforts, with closure of the glottis, occurring in the attacks of cough to which phthisical patients are subject, force the air into this part especially, and also into other regions of less resistance, and thus occasion permanent distension of the vesicles.

SYMPTOMS AND SIGNS.—The signs of this form of emphysema are so often masked by those proper to phthisis that the detection of the former is difficult or impossible. This, however, is of no practical importance in respect to treatment. At times the distension of the vesicles at the apex is so great as to produce bulging in the supra-clavicular region and to overcome the dulness due to deposit by the resonance it occasions.

TREATMENT.—No special treatment beyond that of the causative affections is required.

3. Hypertrophic Lobar Emphysema.

This is a substantive affection, and is much the most important form of the disease, both in its origin and development and in the consequences to which it leads. Though sometimes limited to one lung, or even to a single lobe of one lung, yet it more commonly involves the greater part of both lungs, which are increased in size, as shown by the alteration of the contour of the chest during life and by the appearance of the organs after death. This enlargement of a lobe or of a whole lung is of course the aggregate of the increase in size of the individual vesicles, the changes in which form the pathological units of the disease.

ETIOLOGY.—In no disease is the study of etiology as throwing light on treatment, both medicinal and hygienic, of more value than in emphysema, the important question being as to whether it takes its origin from some immediate mechanical cause acting upon the healthy cell-walls, and thus distending them, or whether they suffer such distension only when they have been previously weakened by some degenerative process in their tissue. The importance of determining this point correctly with reference to treatment is obvious.

In partial and lobular emphysema the change may have been wrought by causes mechanical in their nature and directed specially to the affected parts, such as have been already referred to; but in the general diffused or lobar form of the disease, in which by degrees the greater part or the whole of a lung is involved, we are almost compelled to assume the existence of some degenerative process or tendency coextensive with the malady and determining its existence. That any one form of degeneration is present in all cases has never been proved; indeed, it may be said to have been disproved. Rainey's view, that the change in the air-cells is essentially dependent on fatty degeneration of their walls, was based mainly on observations made upon a single case, and, although favored by the eminent authority of C. J. B. Williams, it has not been substantiated. The same thing must be said of Sir William Jenner's teaching, that fibroid degeneration is the essential lesion. Though both fibroid and fatty changes are found in not a few cases, yet in others a careful examination has failed to detect either the one or the other of them, so that neither can be regarded as the essential condition explaining all cases. Nevertheless, it is probable in the highest degree that a degenerative change of some kind, due to imperfect or perverted nutrition of the cell-walls, always exists in general lobar emphysema, though its nature may sometimes elude observation.

In cases of well-marked emphysema there may be no discoverable morphological changes in the walls of the alveoli, though, as remarked by Hertz,² "a tissue-relaxation may be present in the lung without our being able to recognize any corresponding microscopic abnormality."