GANGRENE OF THE LUNG-.
of the lung is not a common disease of childhood. If the num ber of recorded cases be a fair measure of the relative frequency of the lesion, this form of illness would appear to be much more often met with in adult life than at an earlier age. A contrary opinion has, however, pre vailed, chiefly on the authority of E. Boudet, who in the space of five months met with five cases of pulmonary gangrene in the child. This experience is, however, too exceptional to furnish a satisfactory base for statistical calculation.
The extent of tissue which undergoes the gangrenous change is variable. The lesion may occupy only a limited patch in one of the lobes (circum scribed gangrene), or may involve the whole of the lobe, or even of the lung (diffused gangrene).
gangrene may be the consequence of a general condition affecting the whole body, or may arise in Constitutionally healthy subjects from some local cause which interferes with the circulation of the blood in the lung.
In the first case, a disposition to spontaneous mortification of tissue is manifested as a result of the eruptive fevers, especially measles, and other depressing diseases which cause great prostration of nervous power and lower the nutrition of the whole body. The gangrene is usually of the diffused variety, and the lung is often not the only organ which suffers from the morbid tendency. There may be also gangrene of the gums, the cheeks, the pharynx, and in female children of the vagina, and these com monly precede in point. of time any manifestation of a similar affection of the pulmonary organs.
Of the local causes which interfere with the circulation through the lungs the most common in children is probably the presence of a foreign body in the air-passages. The irritation of the intruding substance sets up a form of pneumonia which may run rapidly into gangrene. Of the few examples of the lesion which have come under ray own care one was a case of this kind. It is narrated shortly in another chapter (see page 529). In cases where lobar pneumonia ends in mortification of the lung the gan grenous lesion cannot be looked as a natural consequence of the pul monary inflammation. Indeed, the inflammatory disease is often not a true croupous pneumonia, but an acute hepatisation of the lung resulting from the presence in the organ of some local irritant. Thus, a variety of pulmonary inflammation with which gangrene is often associated is that due to emboli swept into the pulmonary circulation from an ante-mortem clot formed in the right side of the heart. The irritation of these emboli
causes complete stasis in neighbouring.); vessels, and sets up putrefaction and gangrene in the lung tissue around. BoniHard states that this ac cident may happen in cases of true croupous pneumonia and determine the gangrenous change ; indeed, according to this observer, a peculiar ten dency to the formation of such coagula is a common feature of the pneu monic disease. But even if this be the case, the mortification of tissue is induced by something superadded to the original lesion, and is not to be regarded as an ordinary incident of the croupous form of pulmonary inflammation.
The retention of decomposing secretions in dilated bronchi and cavities in the lung is another local cause of the gangrenous lesion in the Child. It may arise in the course of phthisis, or at the end of an attack of acute catarrhal pneumonia. So, also, extensive hemorrhage into the lung, if it undergo putrefaction, is said to be a cause of gangrenous changes in the surround ing tissue. No doubt in all these cases a debilitated or cachectic state of the system favours the occurrence of pulmonary gangrene; but mortifica-. tion of the lung may arise in children of sound constitution who are well nourished, and whose sanitary surroundings have been to all appearance satisfactory.
Morbid Anatomy.—The commonest form in which gangrene of the lung is met with in the child is that of a patch of mortification situated in the centre of a lobe and surrounded by gray hepatised tissue. The gan grenous patch consists of a pulpy detritus, yellowish-grey, dark green, or slate grey in colour, and intolerably offensive in its smell. It gradually breaks down and leaves a cavity with disintegrated gangrenous shreds ad hering to its walls. This is the circumscribed variety in which the num ber of sphacelated masses may be one or more. In some cases the diseased area is very small, and the lesion consists merely in greenish streaks of gangrenous odour and semi-liquid consistence in the centre of a broncho pneumonic nodule. In other instances we find patches of catarrhal pneumonia enclosing small gangrenous abscesses of variable number, com municating here and there with a bronchus.