CIRCUMSCRIBED EMPYEMA.—In this disease there is a clear history of acute onset, with pleuritic symptoms, and a sudden evacuation of large quantities of pus. The dyspncea is not usually of long standing and generally comes on with comparative suddenness. Distinct dull ness over the purulent area serves to in dicate the true condition present.
The data for forming a correct diag nosis are: The sputum, especially as re gards (a) fcetor, (b) daily amount, (c) physical characters, and (d) method of expectoration. Rotor of breath on coughing. Physical signs of chest, in cluding, the signs of cavities, especially in relation to (a) their size, distribu tion. occurrence, and symmetry; (b) their generally non-progressive char acter and daily variations. The tem perature-range in bronehiectasis varies within very wide limits. It may remain normal for many weeks at a time. even when the sputum is offensive. On the other hand. it may conform to one of the remittent or intermittent types, with a range of as much as four or five degrees. T. D. ,Acland (Practitioner, April, 1902).
Etiology.—When chronic bronchitis is the primary cause of bronchiectasis the patients are usually past middle life, with the exception of the form due to foreign bodies, which may invade the respiratory tract at any age. Dilatation of the bronchi is more likely to present itself during early middle life. As stated, it usually follows primary disor ders of the lung, but it is most prone to do so in persons weakened by diathetic conditions or untoward habits. Under the former may be classed alcoholism, syphilis, gout, and rheumatism. Under the latter alcoholic conditions tending to mechanically induce an increase of the bronchial air-pressure by interfering with the free egress of the atmospheric current; laryngeal paralyses; laryngeal, infralaryngeal, and tracheal hypertro phic processes; neoplasms or aneurisms compressing the trachea or the larger bronchi; foreign bodies in any part of the inferior respiratory tract, etc., are as many possible causative factors. Ex posure to cold and wet, dust, irritating' gases, etc., tend to increase the local dis order by promoting the tendency to local congestion. Adenoid tend to predispose a child to the affec tion.
Prognosis.—Bronchiectasis being, as a rule, a secondary disorder, its prog nosis depends, to a great measure, upon that of the disease acting as cause. Again, the degree of dilatation induced —whether it be cylindrical, circum scribed, localized, or diffused—bears an important influence upon the course of the disease. A slight modification of the bronchial lumen does not necessarily preclude the enjoyment of practically good health; when, however, the lumen of the tubes is markedly increased or studded with saccular dilatations, the infectious processes already described are apt to present themselves at any time and greatly aggravate the danger. Pro gressive emphysema and gangrene are among the complications to be expected. Dilatation and hypertrophy of the right ventricle is frequently observed in cases showing a history of pertussis. On the whole, well-marked bronchiectasis does not tend toward recovery.
A successful result is to be hoped for when appropriate measures are instituted at an early date—measures calculated to aid Nature's curative processes. This, of course, emphasizes the need of an early diagnosis, for, when fibrous replace ment of the pulmonary parenchyma has occurred to any marked extent, a cure is seldom obtained. The expectoration then persists and factor recurs.
Pathology. — The bronchial tube in some cases is only temporarily dilated; this occurs in children after whooping cough or acute pneumonic disease. It is far more common, however, when there has once been dilatation, to have re peated attacks of inflammatory trouble, and the dilatation continually increasing year by year. The effect on the bron chial tubes themselves is probably first of all swelling, sometimes observed in the mucous membrane, which becomes velvety in appearance; the muscular coat of the smaller bronchi then becomes tumefied and its resistance is weakened. Owing to the frequent attacks there is a considerable fibrosis or peribronchial thickening around these dilated bronchi. In some cases, however, instead of hyper trophy of the small tubes there is thin ning and dilatation. When the bronchi are large this dilatation is very striking. On post-mortem are found large cavities with many valvular reflections of the mucous membrane,—au exaggeration of the normal condition of the bronchial tube; so that a large cavity seems to be partitioned off by these valvular septa, especially in the sacculated form of bron chiectasis; there is a small opening, which is the bronchial tube leading to it. Not only are the bronchial tubes affected, but the surrounding area of lung is also involved. It is affected in two ways: First an extensive inflamma tion spreads from the peribronchial con nective tissue, which is continuous with the whole frame-work of the lung. This tissue sends out delicate filaments be tween the alveoli of the lung, and this net-work is again continuous with the pleura and with the septa passing in from the pulmonary pleura. This frame work becomes indurated, the chronic in flammation round the tubes continues until there is an interstitial fibrosis,— an interstitial thickening of the pulmo nary substance round the dilated bron chial tubes. But such a lung with dilated tubes is especially liable to re peated attacks of catarrh or catarrhal pneumonia; therefore specimens some times show evidences of acute catarrhal pneumonia, but more often those of a chronic indurative pneumonia. The consolidation due to chronic pneumonia is distinct from the first, and is char acterized, by a reticular thickening, or fibrosis, of the connective-tissue elements forming the frame-work of the lung. The contents of the alveoli are in many cases consolidated, and the appearance is not of recent, but of organized, ex udation. When stained with eosin and hxmatoxylin, the eosin picks out the blood-vessels. The centre of the alveoli may thus be shown to be filled with small cellular elements and small blood vessels, indicating that it is becoming fibroid and organized.