46 Loc. cit.
COMPLICATIONS AND SEQUELÆ.—The inflammation may extend by contiguity to the lung-parenchyma, pneumonia supervening after a few days, or it may appear to come on simultaneously. It is, however, a rare complication. Lacaze47 reported one case, and that followed thoracentesis; Lugrol reported a similar case.
47 Loc. cit.
Pneumonia does not appear to commence after the effusion has reached the point of compressing the lung. The inflammations frequently are peribronchitic and broncho-pneumonic. The mediastinum may become involved. Fraentzel states that it can never be clearly proved that simple croupous pneumonia exists as a complication of primary pleuritis on the side affected; on the sound side it occurs occasionally. Laennec taught that the compression by the fluid always tended to prevent the occurrence of pneumonia. Anstie's opinion was that when the lung is compressed to carnification it is incapable of inflammation. The most formidable way in which pneumonia may complicate pleurisy is where, considerable effusion existing in one pleura, inflammation attacks the opposite lung. It may be doubted whether this ever occurs in truly primary pleurisies: kidney disease, specific fevers, pyæmia, etc. nearly always precede it. Hyperæmia or congestion of the opposite lung, without its amounting to pneumonia, does occur, and is a very grave complication. The same may be said of double pleurisy and peritonitis as resulting from blood-poisoning. It rarely happens in primary acute pleurisy that both pleuræ become involved. When such is the case, however, it is generally tubercular in its nature, and necessarily a very grave if not a fatal complication. Walshe reports having seen 4 cases of idiopathic bilateral pleurisy in persons thoroughly healthy and perfectly free from constitutional taint of any kind. In all the pericardium was involved, and in 1 the peritoneum. They were all fatal. Acute pericarditis from extension of the inflammatory process is a frequently-occurring complication. When the inflammation extends to the pericardium, the effusion is of the same character as that of the pleurisy, whether it be sero-fibrinous, purulent, or hemorrhagic. It is a complication of great gravity and is sometimes the cause of a fatal termination of the pleurisy. We have never met with endocarditis as a complication, but Fraentzel speaks of having seen it in acute pleurisy in children. Before complete carnification occurs oedema of the lungs may be produced on the diseased side or in the healthy lung. This pulmonary oedema, when it attacks the sound side, is acute, being produced by rapid pulmonary congestion, which causes free, albuminoid, and frothy expectoration, often ending in asphyxia. The serum and albumen of the blood by transudation pass into the bronchi and the alveoli, and fill them more rapidly than they can be expectorated: the subject dies by suffocation. Auscultation reveals fine vesicular râles, characteristic of oedema of the lungs, closely resembling the fine crepitation of pneumonia. Traube has named this oedema pneumonia serosa. Engorgement it certainly is, but it can scarcely be designated a pneumonia. It closely resembles the oedema we meet with after thoracentesis, which has been named by Hérard expectoration albumineuse.
Bronchial catarrhs, when complicating pleurisies, cause dyspnoea, add much to the discomfort, and protract the duration of the disease. Barth48 speaks of dilatation of bronchi as a complication of pleurisy. Woillez49 calls attention to a complication which has been generally overlooked by the authorities—a persistent pain which some patients suffer in the side of the chest a long time after the disease has been cured. The most dangerous complications are syncope, formation of clots, venous emboli, and exaggerated distension of the thoracic walls by the effusion.
48 Mém. de la Soc. Méd. d'Obs., Paris, 1856.
49 Article "Pleurisy," Mal. Aigu. Resp., 1872.
Sequelæ.—The connection of pleurisies, especially chronic, with subsequent tuberculosis, is very generally admitted. Bartholow says: "The importance of pleuritis as a cause of phthisis is hardly sufficiently recognized in inducing tubercular deposit, and by adhesion limiting the movements of the organs, and thus inducing diseases." Anstie says: "It is now well established not merely that pleurisy often occurs in phthisical lung disease, but that pleurisy itself is capable of setting up true tuberculosis even in previously healthy persons. This is specially apt to occur where purulent effusion has been allowed to remain too long in the pleura, or where paracentesis has been performed repeatedly for empyema, the wound being closed in the interval." Modern authors thus consider that a productive field is offered for the bacillus tuberculosis.
Flint states that "in an analysis of 47 cases, in 3 the subsequent development of phthisis was probable, although not demonstrated, and in 1 case only the occurrence of this disease as a sequel was certain." Of 53 cases reported by Blakiston, not one became phthisical during several years after recovery from the pleurisy. Flint says the effect of chronic pleurisy with effusion in a person already phthisical is to arrest or retard for a time the progress of phthisis. We have mentioned the retraction of the chest-walls with deformity of shoulders and spine, and the permanent dislocation of the heart and larger blood-vessels, as serious results, as also the orifices produced by the bursting of the empyemas outwardly. These may all in time, with judicious care and treatment, be very materially lessened, and even cured. Empyema sometimes causes destruction of the periosteum of the ribs and subsequent necrosis. It is questionable whether there are any cases of pleurisy which do not leave more or less extensive adhesions between the two pleural surfaces. In many cases they do not, it is true, seem to injure seriously the general health, yet they must impair the full functions of the lungs. How frequently this is the case is shown at autopsies of persons dying of other diseases, where we find extensive adhesions when we had no reason during life to suspect that such would be the case. Adhesive bands may interfere with the expansion of the lungs and cause chronic bronchial catarrhs, ending in death. Caseous pneumonias are among the sequelæ of pleurisy. When the false membranes are thick and numerous, the lung remains impervious to air and useless. This condition sometimes produces bronchiectasis. While it is true that the lungs, when the effusion is not great enough to actually compress them, sometimes retain their expansibility for three, six, or even eight months, yet there are cases where they do not expand after being bound down for months, and then we have depression of the walls of the chest. Woillez met with 6 such cases.
DIAGNOSIS AND PROGNOSIS.—The diagnosis of the several varieties of pleurisy ought easily to be made by the due appreciation of the general symptoms and physical signs we have enumerated. Cases occur where the differential diagnosis is not free from difficulties, even to the most careful of observers. Pleurisies on the left side are more easily diagnosed than those on the right side. Most of the signs are much more frequently observed on the left than on the opposite side: some of them are rarely met with except on the left. Before the discovery of the science of auscultation and percussion pleurisy and pneumonia were frequently confounded. By their aid the two diseases may ordinarily be diagnosed with precision. In both there are chilliness, fever, cough, and dyspnoea. At the initiation of acute pleurisies, we expect for several days more or less of chilliness, but in pneumonia one, or at most two, decided rigors. The temperature in primary pleurisy rarely goes beyond 100° F. in the first twenty-four hours, whereas in croupous pneumonia, in the same length of time, it not unfrequently rises to 103° F. or 104° F. In consequence of this high temperature in pneumonia the skin becomes hot and dry, with frequently a bright spot on the cheek corresponding to the side of the diseased lung. This is not the case in pleurisies, where, on the contrary, we have a pale, anxious expression of face. The comparatively mild fever of pleurisy is continuous. We have not, as in pneumonia, the marked changes, often of two or three degrees, between the morning and evening temperatures, nor have we critical days (between the fifth and eleventh) where the fever breaks with rapid defervescence.