PULMONARY EMPHYSEMA.
Definition.—Pulmonary emphysema is characterized by the presence of an ex cess of air in the alveoli and infundibu lar passages, with atrophy of the alveolar walls, or by the adventitious presence of air in the interstitial alveolar tissue.
Varieties. — Emphysema is divided into two general varieties: the vesicular, in which the infundibular passages and alveoli are dilated, and the interlobular, in which the air has penetrated the in terstitial alveolar tissue. The vesicular form is, in turn, subdivided into three varieties: the substantive, or hypertrophic, in which there is distension of the alveoli with atrophy of their walls, which gives rise to general enlargement of the lung; the senile, in which there is atrophy and shrinkage of the lung; and the compen satory, in which the air-cells of a part or the whole of one lung become enlarged so as to assume the functions and com pensate for diseased portions of the op posite lung.
Vesicular Emphysema (Substantive, or Hypertrophic, Form).
Symptoms.—The onset and progress of emphysema are so insidious that the disease may be present a long time be fore it is recognized. Slight dyspncea upon exertion is the first symptom usually noticed. This gradually in creases in intensity until the feeling of suffocation is only absent when the pa tient is lying or sitting quietly; as soon, however, as he moves about, ascends stairs, etc., the dyspnoea appears. Under violent exertion and in advanced cases the dyspncea may become exceedingly severe and be attended by cyanosis. The latter, however, may not only attend a severe attack of dyspncea, it is some times present while the patient is not in active motion. As the disease progresses, both the cyanosis and the dyspncea be come more marked. The patient, as a rule, experiences discomfort, not while inhaling, but while exhaling, wheezing and prolongation of the expiratory act suggesting asthma. The wheezing is not apt to be marked, however, unless catarrhal inflammation of the bronchial mucous membrane be also present. The labored breathing interferes with speech, and is a source of fatigue. The inspira tion is sudden and jerky, while the ex piration is prolonged and noisy. As the disease progresses, the dyspncea becomes more distressing, and is aggravated by indiscretions in diet. Congestive dis orders of the internal viscera, the liver, the intestine, the kidneys, and sometimes ascites may appear, followed, in turn, by emaciation and loss of strength.
Most important of all these associated disorders is bronchitis, which compli cates the majority of cases. The attack may be mild and last but a short time and be attended by harassing cough, mucoid expectoration sometimes streaked with blood; or it may assume a more violent and continuous form, in which the cough and the dyspncea, combined, so closely simulate an access of typical asthma as to mislead the medical attend ant. The sputa are apt to be muco-puru
lent in such cases, and hiemoptyses sug gesting the early signs of pulmonary tuberculosis are frequently observed. The slow progress of the major disease and the recurrence of the acute symp toms of bronchitis every winter, serve, however, to establish the diagnosis. During the summer emphysematous pa tients are sometimes sufficiently comfort able to lead to the belief that a complete cure has been effected. This form is frequently observed in young adults, whereas continuation of the emphysem atous symptoms throughout the year, though characterized by exacerbations during the winter, is usually met with among old subjects. Cardiac symptoms often prevail, the result of hypertrophy followed by dilatation. These, in turn, are brought on by pulmonary congestion induced by the interference with circula tion in the diseased areas.
Diagnosis.—Physical examination of advanced cases of emphysema renders a diagnosis comparatively easy in the ma jority of cases. The "barrel-chest," hav ing all its diameters, especially the an tero-posterior, markedly increased; the prominent scapulm and increased spinal curve and rounded back; the limited motion of the ribs, with unusually wide areas between them; and the prominent costal cartilages and sternum, below which the deep sternal fossa appears in striking contrast, are typical signs. The muscles of the thorax may be enlarged, and the thorax appear raised. The clavicles may stand out horizontally to an unusual degree, causing the head to sink deeper between the shoulders. In less advanced cases, however, the tho racic changes are, of course, less marked and the disease may have lasted a con siderable time without giving rise to de formation of the chest. In all, however, and varying in degree with the progress of the disease, there is reduction of the relative expansion; the chest increas ingly refuses to expand, notwithstanding the manifest muscular efforts which seem only to raise the entire chest up ward. In truth, it is to inability to liberate imprisoned air that the reduced chest-expansion is due, the residual air being greatly in excess, and so filling the emphysematous cavities as to prevent contraction of their walls. The resili ency of the latter is further impeded by the diseased condition of the alveolar structures. Mensuration shows that, while normal expansion reaches three to four inches, an emphysematous chest sometimes does not expand an inch; in rare cases no expansion can be noted. The impact of the heart is often lost, the organ being depressed or concealed by overlapping lung.