5 Klinik der Brustkrankheiten, vol. i. p. 827.
6 Boston Med. and Surg. Journal, vol. xcv. p. 486.
7 Gangræna Pulmonum bei Kindern, 1872.
Of the 46 Vienna Hospital cases, 43 were male and 3 female. Huntington's cases were males 24, females 8. Of Lebert's own 32 cases, 22 were males; of the 32 others summarized by him, in 4 sex was not mentioned, and of the remainder 17 were males and 11 females. These figures show the large predominance of males in the liability to attack.
Exciting Causes.—They may be classified as pulmonary and extra-pulmonary. The influence of the alcoholic habit has been referred to above among predisposing causes: debauches are a frequent antecedent, especially in hospital cases, by means of resulting pulmonary hyperæmia and drunkard's pneumonia. Its association with croupous pneumonia may be assumed as settled after some warm disputes. The pneumonia of Bright's disease and putrid bronchitis are occasionally causative; bronchiectasies result in it not unfrequently. Extension of diphtheritic inflammation from the tracheal and bronchial mucous membrane is another form. The catarrhal pneumonia secondary to measles may produce it in children.
Embolism is the most frequent cause in the class of extra-pulmonary causes. It may be mechanical or infecting. A bronchial artery may be plugged so as to produce a gangrenous slough from mechanical cutting off of nutrition. Embolism of the pulmonary artery branches is more frequent, and by bringing about infarction and apoplexy may produce gangrene. Of the infecting variety may be mentioned emboli from the peripheral veins, as in surgical or uterine phlebitis, or from cerebral sinuses secondarily involved from otitis. Other causes acting from without on the lungs are foreign bodies, as particles of food passing beyond the trachea into the lungs, as in case of the insane or drunkards, and blows on the walls of the chest. These latter are capable of producing not only the ordinary phenomena of contusion-pneumonia8 but gangrene, and without evidence of external injury or fracture of the ribs.
8 M. Litten, p. 26, vol. v., Zeitschrift für klinische Medicin.
SYMPTOMATOLOGY.—Gangrene of the lung is the termination of a process the beginning and progress of which are not declared or cannot be followed through characteristic symptoms. Even its final occurrence may remain unknown if a communication be not established with a bronchus, which event is followed by the true symptoms, the expectoration and its odor. Whatever symptoms occur previous to that event may occur independent of it. Adopting Lebert's dictum,9 gangrene of the lung is not a pathological unit. As its pathogenesis varies, so does its symptomatology. A feature common to its several varieties is marked constitutional depression and variations from the typical form of the disease in which it occurs. If pneumonia, croupous or catarrhal, be the precedent or associated disease, it will be marked by soft and feeble and frequent pulse, restlessness, dulness or distress of countenance, more or less cyanosis, cool and relaxed skin, possibly delirium, dry tongue, unusual dyspnoea and pleuritic pain, copious prune-juice expectoration, irregular or non-typical temperatures. Along with these functional variations occur some in physical signs, as a lesser amount of dulness or of bronchial breathing, indicative of less structural density and corresponding exudation. A case with such an evolution may afford a presumption of an outcome in gangrene, but appearance of the characteristic expectoration and fetor is necessary to exclude it from irregular forms of pneumonia, which have no such termination. The same general remark applies to the cases of gangrene in bronchiectasic cavities. Perhaps some aggravation of the general condition may excite apprehension, but the characteristic phenomena of expectoration, odor, etc. must decide. If the cause be of embolic origin, we may expect some suddenness and perhaps shock in the beginning, and later the evidences of a more limited inflammation of the lung-tissue, such as circumscribed dulness and modified respiratory sound, which finally end in those indicating destruction of lung-tissue.
9 Op. cit., p. 803.
The macroscopic characters of the expectoration are those of a putrid or fetid liquid of varying shades of color, ashy gray, dirty green, or greenish-yellow, prune-juice, or more or less hemorrhagic. The odor, which is at first so fetid and penetrating, often disappears after the expectoration has been standing a while. It is separable, as first described by Traube,10 into three principal layers. The uppermost, covered with a layer of foam, consists of, first, dirty green, crumbling, confluent lumps; second, of larger, homogeneous, green muco-purulent masses; and, third, of whitish-gray, transparent, mucous masses. The second layer is formed of a colorless fluid. At the bottom is a fine yellowish-white sediment. Microscopically are found fat-acid crystals, many large fat-drops, and finely granular débris, masses of free, black pigment. It is said elastic tissue is nowhere to be found, but to this statement there are no doubt exceptions. Other bodies have been found by Leyden and Jaffee,11 which they named Leptothrix pulmonalis. Kannenberg,12 besides the above forms, found constantly infusoria of the family of monads in the sputa of 11 out of 14 cases of pulmonary gangrene. He considers them peculiar to the processes of decomposition in the lungs.