DEFINITION.—A circumscribed suppuration of the lung, resulting in a cavity.
SYNONYMS.—Abcés du poumon; Lungenabscess.
HISTORY.—The ancients described abscess of the lung, and placed it among the terminations of the inflammation of that organ. They believed that if the inflammation did not resolve itself by the fourteenth or twenty-first day its termination was to be by suppuration. Hippocrates, Van Swieten, and others are mentioned among those who maintained these views and consequent frequency of such cases which prevailed until physical methods and pathological investigation proved their incorrectness. J. P. Frank, Bayle, and Cayol1 are given credit for a partial reversal of this opinion. Avenbrugger,2 a pupil of Van Swieten, in describing vomicæ, divides them into two kinds—the ichorous and the purulent. By the purulent vomica he means an encysted abscess of the chest resulting from the conversion of an inflamed spot into a white, thick, glutinous, fatty matter. When these communicate with the bronchi and discharge any of their contents by expectoration, they are called open; otherwise, close or shut. He gives symptoms and signs belonging to the respective varieties. Corvisart, in his comments on these propositions, says: "In fact, the purulent vomica is always the result of an inflammation, more or less acute, of the lung." He makes distinctions between the various kinds of purulent vomica and the ichorous vomica. Laennec, as in many other subjects of which he treated, has the credit of placing this one on its modern basis, at least so far as the frequent termination of pneumonia in abscess is concerned. Among English writers Stokes deserves especial mention. Abscess was the fifth and the last of the stages of pneumonia, according to his classification. He treated largely of the perforating abscess. Traube, Trousseau, and Leyden are among those who have contributed largely to the elucidation of the subject. The latter has especially claimed for this subject a more prominent place in the literature of practical medicine, and has strongly enforced his views.
1 Nouv. Dict. de Méd. et de Chirurgie, tome xxix. p. 394; and Leyden, "Ueber Lungenabscess," Sammlung klinische Vorträge, von Richard Volkmann, Nos. 114, 115.
2 On Percussion of the Chest, a translation of Avenbrugger's original treatise by John Forbes, with comment by Corvisart, 1761–1808, pp. 38, 43, etc.
ETIOLOGY.—Predisposing Causes.—Everything tending to debilitate the constitution may become a factor in the production of abscess of the lung. Senile constitutions, Bright's disease, chronic alcoholism, diabetes mellitus, and insanity are some of the predisposing causes.
Exciting Causes.—These may be divided, as in the case of gangrene, into the pulmonary, or those originating in the lung or pleura, and the intra-pulmonary, or those originating outside of the lung or pleura. Among the former are included pneumonia and empyema, perforating and discharging into the lung, or one variety of Stokes's perforating abscess, pulmonary apoplexy, and suppurating bronchial glands, opening up a passage through the lung and bronchial tube. Either croupous or catarrhal pneumonia may be associated with or terminate in pneumonia. Among the latter, or extra-pulmonary class are included cases of embolism from the right heart, producing infarction, or from the systemic veins. These emboli carry with them the productive capacity of suppuration. Abscess external to thoracic walls, as in deep-seated mastitis, will at times perforate the walls and enter the lung. Abscesses of the liver not infrequently perforate the diaphragm, and are discharged through the lung.
Foreign bodies in the bronchi may ulcerate through them and produce suppuration of the lung, which may finally open a way externally through the chest-walls.
SYMPTOMATOLOGY.—The symptoms of abscess of the lung, as may be inferred from the enumeration of causes, are divisible into two categories—one including those symptoms with which the abscess may be associated, but which do not necessarily prognosticate it; and the other including the symptoms which indicate the abscess as a fact accomplished. In the simplest and most frequent clinical form, that following pneumonia, the early symptoms would be those of a severe and irregular form, as shown by very troublesome and uncontrollable cough or unusual pain or respiratory embarrassment, high fever, but at that time fairly typical pneumonic temperature, great prostration, etc. These may all diminish in due time, and mostly do without suppuration following. A return of pain, dyspnoea, fever, and general distress should awaken suspicion, yet they may be the result of an extension of pneumonia to other portions of the lungs. Rigors and sweats and increased depression would point to a suppurative process and under such circumstances to the lung as the locality. We cannot, then, positively predict an abscess. It is suspected when a more or less copious eruption of purulent discharge occurs suddenly, and sometimes the discharge is so abundant and pus-like that any other alternative than abscess is very remote; at other times the discharge is small in quantity. The proof of physical cavernous signs is the final step. This is often difficult. A slightly greater increase of lung-density, probably at the middle or upper part, with imperfect bronchial breathing, the appearance of a few moist râles or crepitus, the gradual increase of these and merging into coarser crepitus, and revelation of more or less of the cavity signs, is the physical history of many cases of abscess of the lung. Others have a much more pronounced course, such as the cases of so-called gangrenous abscess—a sort of connecting link between gangrene and abscess of the lung. The breaking down of tissue is ostensibly very sudden, and the cavernous signs are very soon unmistakable. Other clinical forms are the pyæmia, to be distinguished by the antecedent history, which will reveal a source for infectious emboli. The abscesses are usually multiple and small, so that their precise locality cannot be made out. The proof of infectious transportation is sudden pneumonic symptoms, as pain, tinged and finally purulent expectoration. Rupture into pleura may occur and produce empyema. Rupture of hepatic abscess and discharge through the lungs is also a clinical form shown by this antecedent event, pointing to hepatic inflammation. The egress of the pus is sometimes through a narrow track, and not by a reservoir within the pulmonary tissue; at other times the lung is really excavated. The discharge of pus is usually copious and paroxysmal. Leyden recognizes as his third class a form of chronic abscess, or one coming on during a case of chronic pneumonia and bearing great resemblance to a variety of phthisis. Its general symptoms are much the same as in the acute variety, differentiated by the element of time.