ABSCESS OF THE LUNG.
BY WILLIAM CARSON, M.D.
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.
COURSE.—It may be said, in a general way, that the etiology has much to do with its course. If the cause be pneumonia, the course will be such as the detail of symptoms already given shows. In some unknown way the natural course of the disease is interrupted, and what promises to be an average case is followed by the characteristic features of abscess. If pyæmia be the precedent condition, a peculiar form of pneumonia, embolic in origin, appears, and abscesses again follow. Greater septicity and rapidity of destruction are probable sequences. The perforating abscesses are subject to modifying influences of mechanical effect, such as gravitation and the resistance of tissues, and have their peculiar course, which is often marked by great chronicity.
TERMINATION.—In the course of seventeen years the reports of the Cincinnati Hospital show that there have been 6 cases of abscess of the lung treated there. Of these 4 died and 2 were discharged as improved. These figures show the infrequency of such cases, and also represent a greater mortality than probably occurs in the non-hospital class. We know of no large statistics which show what is the percentage of recoveries. Our own experience in private practice gives a majority of recoveries. They were cases following typhoid fever, croupous and catarrhal pneumonia, and hepatic abscess. A termination in a chronic cavity now and then happens: perforation of the pleural cavity, with subsequent pyo-pneumothorax, discharge externally through an intercostal space, or even extension into the abdominal cavity, are among the actual events of such abscesses.
DURATION.—The duration of an ordinary case is subject to wide variations between one and six months. A few cases are recorded of several years' duration. Previous constitutional condition has much to do with this element. The degree of infectiousness in the pyæmic class is important as to time. The abscesses become a subordinate condition in the fate of the case. In this connection we may also refer to Leyden's third variety, a so-called chronic abscess.
PATHOLOGY.—A close parallelism, etiologically and otherwise, is observable up to certain points between gangrene and abscess of the lung. Both are products of, or associated with, pneumonia. That which finally determines whether the result shall be gangrene or abscess is unknown to us. In the article on [GANGRENE OF THE LUNG] some investigations are referred to which point to a probable solution in the existence of specific forms having special pathogenetic force. The tendency of experimental and clinical investigations is to connect the suppurative process closely with the product of specific germs. Ogston in 65 cases of acute abscess found micrococci present in all of them. Obstruction of blood-vessels in the centre of the pneumonic area or on the margin of the abscess walls is an important anatomical element in the production of abscess, and it is claimed that it is often due to colonies of micrococci within their calibre; so that it is probable that there are both mechanical and biological or chemical influences at work. If the view of the zymotic and infectious character of pneumonia be tenable, the contingency of an abscess developing in its course would seem not very remote. Yet the proportion of cases of abscess from pneumonia is not more than 2 per cent. Leyden's high authority supports the idea of the essential and specific differences in the chemical and morphological peculiarities of gangrene and abscess of the lung, but the subject is as yet on a hypothetical basis.
MORBID ANATOMY.—The fresh cavity, generally in the upper lobe, has rough, ragged, and irregular walls, and may have bridles of the more resistant structures, as bronchi and vessels, crossing it. Such a cavity is quite likely to contain portions of undissolved parenchyma or more or less malodorous pus. The older cavity becomes smoother walled, and of more regular limits and cleaner contents. A gradation from granular hepatization through congested to crepitant tissue is almost uniform in the varieties of abscess, whether simple or pyæmic. In addition, some peculiarities are observable in the latter. These are usually several, varying in size from a pea or less to a walnut, some round and others wedge-shaped; others lying superficially and forming slight elevations on the pleural surface. In proportion to the curative progress the cavity will contract and disappear, occasionally leaving behind a cicatricial mark. A lining pus-secreting membrane will sometimes form, resulting in such a limitation of morbid action and such a disappearance of reactionary symptoms as to make the disease entirely local, but quite chronic.
DIAGNOSIS.—The more or less sudden and copious expectoration of pus, without a specially offensive odor, in the course of a case having up to that time the history of a pneumonia, would be considered as due to the development of an abscess in the lung. Some degree of fetor in breath and expectoration is observed, but it is far different from that of gangrene. The detection of the débris of lung-structure in coarse particles, and the microscopic discovery of elastic lung-tissue, are important diagnostic points in contradistinction from the solution of tissue that gangrene usually effects upon the parenchyma of the lung. According to Leyden's3 very complete investigations, the microscope reveals fatty crystals, mostly in roundish fragments, of the size of the epithelium of the lung and of a brilliant structure; pigment-débris of a yellowish-brown or brownish-red color; hæmatoidin and bilirubin, which Traube thought were due to hemorrhagic infarction, but which Leyden has observed in all of his cases; and, lastly, micrococci, in the well-known form of the round, granular micrococci colonies, which differ from those in gangrenous fragments in that they show very little movement and do not give the iodine reaction.
3 "Ueber Lungenabscess," Volkmann's klin. Vorträge, p. 994.
Difficulties of diagnosis arise in the case of an empyema discharging through the bronchi, or of an encysted empyema discharging through the third or fourth intercostal space in front; also, between abscess of the superior portion of the liver and one in the base of the lung, or between the latter and a pyo-pneumothorax. Very careful study of the history in each case is of the first importance. Where this is not attainable the difficulty is often much increased. In the case of the empyema the discharge is more profuse at each time, the whole amount in a given period is much greater, and the time of opening is much delayed beyond that of the pneumonic abscess. Trousseau gives the case of a child who brought up for more than six months 200 grammes of pus daily. He makes children an exception to the rule as to the late opening of the pleural abscesses. In the encysted empyema discharging either internally or externally the difficulties are greater. A portion of the lung-tissue may be so near behind the deposit of matter as to make the physical signs confusing if the pus has opened externally. Some of these and of the interlobular deposits it is almost impossible to diagnose.
In hepatic abscess opening into the lung and bronchi the discharge is copious, dirty brown, paroxysmal, and will generally, on careful observation, show the bile color or its chemical reactions or some microscopic débris of the liver. In Leyden's third class, or the chronic abscess arising in the course of chronic pneumonia, the history is so much like that of some forms of phthisis as scarcely to serve in diagnosis. He thinks there are some macroscopic and microscopic appearances which may serve for diagnosis. There are in the expectoration dark and compact pieces of greenish-black color, not unlike plugs of pus, and larger, black-pigmented fragments of parenchyma, from a pin's head to a hempseed in size. Microscopically, they consist of a close and strongly-pigmented parenchyma, which seldom reveals alveolar structure. They show fatty degeneration and cholesterin plates. This class of cases is mostly without fever. The application of the bacilli-tuberculosis test would seem to offer some assistance in diagnosis.
PROGNOSIS.—A grave prognosis may be formulated if there be a history of feeble constitution, and especially if it be further impaired by habits of intemperance, if the patient belong to either extreme of age, if there has been a recent debauch, or if there be wide variation from the typical form of pneumonia. Variations will be shown in such a complexus of symptoms as follows: fever of low grade, subject to extremes in range; feeble and frequent pulse, but not so marked as in gangrene of the lung; dyspnoea, objective and subjective; typhoid depression; tongue dryish; delirium; copious and fetid or difficult expectoration; physical signs of extensive lesion, such as a large cavity with a large outlying pneumonic area. A favorable prognosis would be conditioned on the appearance of a fewer number of these symptoms or on their evolution in a milder form.
The capacity of the patient to endure a long-continued suppurative discharge is principally determined by his natural vigor and his ability to assimilate food, other elements, such as extent of injury to the lung, being the same. A well-defined superficial cavity would be more favorable, because within surgical relief.
In the pyæmic variety the force of the infectious element will determine largely the result. Chills and sweats are important prognostic elements in such a case.
In the secondary abscesses of either the empyematous or hepatic variety prognosis is grave—more so in the latter than in the former, because surgical procedure would be more promising in the former, and because of the implication of an organ so liable to destructive inflammation as the liver. A long and tedious course of suppuration is possible in either. The dangers in an established abscess arise from liabilities to septic infection and exhaustion consequent on want of reparative power and persistent suppuration.
TREATMENT.—The treatment of abscess differs little if at all from that of gangrene of the lung. The tendencies of the two diseases toward exhaustion and infection are similar, but are less pronounced in the former. The same remedies are necessary in both, such as stimulants, tonics, antiseptics, anodynes, and expectorants internally, inhalations and drainage externally; brandy and malt liquors as stimulants; nourishing and concentrated food at frequent intervals; quinine as tonic and antiseptic; carbolic acid and turpentine as most valuable antiseptics (the latter being also an excellent stimulant); eucalyptus in cases of profuse as well as fetid discharge; carbonate of ammonia, senega, as expectorants; morphine and codeine or anodynes to control cough; carbolic acid for inhalation; and in cases of definitely localized cavities a free opening to be made with antiseptic injections.
Successful cases of surgical interference are reported, and such treatment is now recognized as proper when the system is giving way under septic poison, evinced in chills, sweats, and great prostration, where the purulent discharge is fitful and imperfect, and where the physical signs are clear enough to show the locality of the abscess.