EMPHYSENIA OF THE LUNGS (CHRONIC, ACUTE, AND INTERSTITIAL) Form, Etiology and Pathogenesis.—We must distinguish three kinds of emphysema; genuine chronic, acute (pulmonary inflation), and interstitial emphysema.
1. The chronic, alveolar, generalized emphysema (rarefying emphy sema) which runs its course with pertnanent enlargement of the alveoli, obliteration of alveolar septa and capillaries, loss of elasticity, which is the form so frequently seen in adults, is rarely and only exceptionally met with in ohler children, where it presents the same symptoms as in adults. We shall, therefore, not consider it more fully, except to men tion the fact that many adults date back the beginning of their emphy sema to the later period of childhood. In certain cases, gradual velopment of the disease is seen in long continued bronchial asthma, adenoid vegetations, chronic, relapsing bronchitis. and in enlargement of the bronchial glands.
,More frequently, a partial chronic emphysema develops in the neighborhood of portions of the lungs which have been deprived of air for some time, as in tuberculosis, and in rachitis producing deformity of the thorax, in which instance the habitual dyspncea also assists. In these cases, vicarious emphysema is also indicated, which most particu larly affects the sound lung in cases of contraction of an entire lung. In these cases, recovery is still possible after years, provided the origi nal trouble. disappears, since a long period of time is necessary to produce a loss of the elastic element.
2. In children, acute alveolar emphysema (inflammation of the lungs) is found much more frequently than genuine, chronic emphysema. The same may occur secondarily in all diseases which are accompanied by forced or labored respiration, in which instances the increased expira tory pressure is often responsible (whooping-cough, severe cough); often times also the forced inspiratory breathing and the diminution of the respiratory surfaces (croup, and tracheal-bronchial stenoses, bronchia litis, bronchopneumonia, etc.). Besides atelectases and consolidation of the lungs it also often appears "xicariously." Under these circum stances there is simply a distention of the pulmonary alveoli with the respective portion of lung. On section, these areas are pale, prominent, and do not collapse. Beyond the distention of the alveolus no histologi cal changes are found. The anterior portions of the lungs and their bor ders are most frequently affected. Inflation of the anterior portions of the lungs is e.specially frequent in very young infants, and is almost invariably the rule in bronchiolitis and bronchopneumonia. Forced pulmonary inflation in asphyxiated newborn infants may cause a general pulmonary distention, and in rare eases may also occur in bronchial croup (Variot).
3. Interstitial emphysema is seen more frequently in children than in adults. It may- develop as a subpleural or interlobular, but seldom as a peribronchial affection, and may extend through the inediastinum to underneath the external skin. On post-mortem examination after all kinds of diseases accompanied by severe coughing and dyspncea, air vesicles in various stages of distention, movable and often arranged in chain-like rows, are found beneath the' pleura. They are the result of rupture of the alveoli. A similar direct interlobular escape of air from
small bronchi into the peribronchitie tissue is most likely to occur in localized tuberculosis. But only interstitial emphysema produces clinical symptoms after it has increased in extent and penetrated the mediastinurn, usually- only when it has travelled along the trachea or (esophagus and appears as a subcutaneous emphysema. Subcutaneous emphysema (originating from the lungs) is in general observed only in young infants after severe dyspmea, and violent coughing, par ticularly in pertussis, as well as in diphtheria, tuberculosis, and bronchopneumonia.
The symptoms of chronic emphysema are sufficiently well known as they occur in the adult. It is to be noted that the barrel-shaped thorax is frequently absent in children. The acute pulmonary disten tion is often overshado-wed by the underlying disease, and remains un noticed. The attention is most apt to be directed to this contlition when the course of the disease is prolonged, and in cases of bronchiolitis. In extensive emphysema there are found a diminution of the respiratory murmur anteriorly, prominence of the anterior portion of the thorax, together with symptoms of descent of the pulmonary marg,in in the right anterior mamillary line, besides a diminution of the cardiac dul ness, which are unmistakable signs. After the termination of the primary condition, the pulmonary inflation recedes, and usually disappears com pletely even after the most obstinate attack of whooping-cough. Inter stitial emphysema progresses without any symptoms. Even in cases of extensive accumulation in the mediastinum, it is only suspected when there is a rapid increase of clyspncea and cyanosis (compression of the large vessels); but on the other hand it is easily recognized a-here it appears subcutaneously. There usually appears first on the neck at the base of the sternum a soft, crackling swelling, more rarely first on the cheek. Within 12-30 hours the emphysema may spread rapidly to the neck, head, lateral portions of the thorax, and the rest of the upper portion of the body. It proves rapidly fatal in most cases. When the underlying conditions are favorable, the extravasated air is absorbed within 1-2 weeks.
From what has been said the diagnosis is obvious. In cases of unusual size of the lungs and the corresponding depth of the pulmonary border, the readily movable margins of the lungs protect against the erroneous assumption of a chronic emphysema. An acute inflation is usually found only on careful percussion of the pulmonary margins.
The prognosis is dependent upon the primary condition. The treatment of chronic emphysema is the same as in the adult, though pneumatic therapy is less frequently indicated, and respiratory gym nastics, eventually with manual aid iu expiration, is sufficient. In the first place, we should seek to. cure the primary disease (bronchitis, asthma). Sojourn in the country, forest air, and mountains, prove use ful in these cases. Also in addition a course of treatment with arsenic and iodides. After the termination of the primary disease the acute inflammation of the lungs subsides of its own accord. In subcutaneous emphysema, capillary puncture and pressing out of the air are to be tried, in addition to relief of the dyspnct.a.