PLEURISY, or PLEURITIS, inflammation of the pleura or serous membrane investing the lungs and lining the interior of the thoracic cavity. It is a common form of chest complaint, and may be either acute or chronic, more frequently the former.
The morbid changes which the pleura undergoes when inflamed are similar to those which take place in other .serous membranes, such as the peritoneum (see PERITONITIS), and consist of three chief conditions or stages of pro-gress. (1) Inflammatory congestion and infiltration of the pleura, which may spread to the tissues of the lung on the one hand, and to those of the chest wall on the other. (2) Exudation of lymph on the pleural surfaces. This lymph is of variable consistence, sometimes composed of thin and easily separated pellicles, or of extensive thick masses or strata, or again showing itself in the form of a otough membrane. It is of greyish-yellow colour, and microscopically consists mainly of coagulated fibrine along with epithelial cells and red and white blood corpuscles. Its presence causes roughening of the two pleural surfaces, which, slightly separated in health, may now be brought into contact by bands of lymph extending between them. These bands may break up or may become organized by the development of new blood-vessels, and adhering per-manently may obliterate throughout a greater or less space the pleural sac, and interfere to some extent with the fiee play of the lungs. (3) Effusion of fluid into the pleural cavity. This fluid may vary in its characters. Most commonly it is clear or slightly turbid, of yellowish-green colour, sero-fibrinous, and containing flocculi of lymph. In bad constitutions or in cases where the pleurisy complicates some severe form of disease, e.g., the acute infectious maladies, it is deeply-coloured, bile-stained, sero-purulent, purulent, or bloody, occasionally containing bubbles of air from decomposition. The amount may vary from an almost inappreciable quantity to a gallon or more. When large in quantity it may fill to distension the pleural sac, bulge out the thoracic wall externally, and compress more or less completely the lung, which may in such cases have all its air displaced and be reduced to a mere fraction of its natural bulk lying squeezed up upon its own root. Other organs, such as the heart and liver, may in conse-quence of the presence of the fluid be shifted away from their normal position. In favourable cases the fluid is absorbed more or less completely and the pleural surfaces again may unite by adhesions; or, all traces of inflam-matory products having disappeared, the pleura may be restored to its normal condition. When the fluid is not speedily absorbed it may remain long in the cavity and compress the lung to such a degree as to render it incapable of re-expansion as the effusion passes slowly away. The consequence is that the chest wall falls in, the ribs become approximated, the shoulder is lowered, the spine becomes curved and internal organs permanently displaced, while the affected side scarcely moves in respiration. Some-times the unabsorbed fluid becomes purulent, and an empyasma is the result. In such a case the matter seeks vent in some direction, and it may point as an abscess upon the chest or abdominal wall, or on the other hand burst into the lung and be discharged by the mouth. It must be observed that many cases of pleurisy do not reach the stage of effusion, the inflammation terminating with the exudation of lymph. To this form the term dry pleurisy is applied. Further pleurisy may be limited to a very small area, or, on the contrary, may affect throughout a greater or less extent the pleural surfaces of both lungs.
Pleurisy frequently arises from exposure to cold; hence it is more common in the colder weather; but besides this various other causes are connected with its occurrence. Thus it is often associated with other forms of disease within the chest, more particularly pneumonia, bronchitis, and phthisis, and also occasionally accompanies pericarditis. Again it is apt to occur as a secondary disease in certain morbid constitutional states, e.g., the infectious fevers, rheumatism, gout, Bright's disease, diabetes, &c. Further, wounds or injuries of the thoracic walls are apt to set up pleurisy, and the rupture of a phthisical cavity in the lungs causing the escape of air and matter into the pleura has usually a similar effect.
The symptoms of pleurisy vary, being generally well-marked, but sometimes obscure. In the case of dry pleurisy, which is on the whole the milder form, the chief symptom is a sharp pain in the side, felt especially in breathing. Fever may or may not be present. There is slight dry cough; the breathing is quicker than natural, and is shallow and of catching character. If much pain is present the body leans somewhat to the affected side, to relax the tension on the intercostal muscles and their covering, which are even tender to touch. On listening to the chest by the stethoscope the physician recognizes sooner or later " friction," a superficial rough rubbing sound, occurring only with the respiratory acts and ceasing when the breath is held. It is due to the coming together during respiration of the two pleural surfaces which are roughened by the exuded lymph. The patient may him-self be aware of this rubbing sensation, and its vibration or fremitus may be felt by the hand laid upon the thoracic wall during breathing. This form of pleurisy may be limited or may extend over the greater part of one or both sides. It is a not unfrequent complication of phthisis in all its stages. In general it disappears in a short time, and complete recovery takes place; or on the other hand extensive adhesions may form between the costal and pulmonary surfaces of the pleura, preventing uniform expansion of the lung in respiration, and leading to emphysema. Although not of itself attended with danger, dry pleurisy is sometimes preliminary to more serious lung disease, and is always therefore to be regarded while it lasts with some degree of anxiety.
Pleurisy with effusion is usually more severe than dry pleurisy, and, although it may in some cases develop insidi-ously, it is in general ushered in sharply by rigors and fever, like other acute inflammatory diseases. Pain is felt in the side or breast, of a severe cutting character, referred usually to the neighbourhood of the nipple, but it may be also at some distance from the affected part, such as through the middle of the body or in the abdominal or iliac regions. This transference of the pain occasionally misleads the medical examiner. The pain is greatest at the outset, and tends to abate as the effusion takes place. A dry cough is almost always present, which is particularly distressing owing to the increased pain the effort excites. The breathing is painful and difficult, tending to become shorter and shallower as the disease advances and the lung on the affected side becomes compressed. The patient at first lies most easily on the sound side, but as the effusion increases he finds his most comfortable position on his back or on the affected side. When there is very copious effusion and, as is apt to happen, great congestion of the other lung, or disease affecting it, the patient's breathing may be so embarrassed that he cannot lie down.
On physical examination of the chest the following are among the chief points observed. (1) On inspection there is more or less bulging of the side affected, obliteration of the intercostal spaces, and sometimes elevation of the shoulder. (2) On palpation with the hand applied to the side there is diminished expansion of one-half of the thorax, and the normal vocal fremitus is abolished. Should the effusion be on the right side and copious, the liver may be felt to have been pushed downwards, and the heart somewhat displaced to the left; while if the effusion be on the left side the heart is displaced to the right. (3) On percussion there is absolute dulness over the seat of the effusion. If the fluid does not fill the pleural sac the floating lung may yield a hyper-resonant note. (4) On auscultation the natural breath sound is in-audible over the effusion. Should the latter be only partial the breathing is clear and somewhat harsh, with or without friction, and the voice sound is asgophonic. Posteriorly there may be heard tubular breathing with asgophony. These various physical signs render it im-possible to mistake the disease for other maladies the symptoms of which may bear a resemblance to it, such as pleurodynia.
The absorption or removal of the fluid is marked by the disappearance or diminution of the above-mentioned physical signs, except that of percussion dulness, which may last a long time, and is probably due in part to the thickened pleura. Friction may again be heard as the fluid passes away and the two pleural surfaces come together. The displaced organs are restored to their position, and the compressed lung re-expanded. Fre-quently this expansion is only partial, and consequently, as already indicated, the chest falls in, the respiration on one side is imperfectly performed, and the patient remains permanently short in breathing to a greater or less degree.
In most instances the termination is favourable, the acute symptoms subsiding and the fluid (if not drawn off) gradually or rapidly becoming absorbed, sometimes after re-accumulation. On the other hand it may remain long without undergoing much change, and thus a condition of chronic pleurisy becomes established. Such cases are to be viewed with suspicion, particularly in those who are predisposed to phthisis, of which it is sometimes the precursor.
Pleurisy may exist in a latent form, the patient going about for weeks with a large accumulation of fluid in his thorax, the ordinary acute symptoms never having been present in any marked degree. Cases of this sort are often protracted, and their results unsatisfactory as regards complete recovery.
The chief dangers in pleurisy are the occurrence of a large and rapid effusion, particularly if both sides be affected, causing much embarrassment to the breathing and tendency to collapse; the formation of an empytema (often marked by recurring rigors and hectic symptoms); severe collateral congestion of the other lung; imperfect recovery; and the supervention of phthisis. Further the consequences are apt to be more serious where pleurisy exists as a complication of some pre-existing disease.
The treatment of pleurisy need only be alluded to in general terms. It will necessarily depend as regards details upon the form and severity of the attack. One of the first symptoms calling for treatment is the pain. Opiates in the form of morphia or Dover's powder are useful along with the application to the chest of hot poultices or fomentations sprinkled with turpentine. In severe cases much relief to the pain and difficulty of breathing may be afforded by the application of a few leeches to the side. Cases of simple dry pleurisy usually soon yield to such treatment, aided if need be by the application of a fly-blister or of iodine to the chest. The fixing as far as possible of the one side of the thorax by means, of cross straps of adhesive plaster according to the plan recom-mended by Dr Roberts seems of use in many instances. In the case of pleurisy with effusion, in addition to these measures, including blistering, the internal use of saline cathartics and diuretics appears to be often of service in diminishing the amount of the fluid in the pleural cavity, as are also powerful diaphoretics such as pilocarpin. When these measures fail to reduce the effusion the question of the artificial removal of the fluid comes to be considered. The operation (thoracentesis) was practised by the ancient physicians, but was revived in modern times by Trousseau in France and Bowditch in America, by the latter of whom an excellent instrument was devised for emptying the chest, which, however, has been displaced in practice by the still more convenient aspirator. The propriety of this proceeding in pleurisy with effusion has been much discussed, but there now appears to be a general consent that in cases of extensive accumulation, when other means such as those briefly referred to fail to reduce or remove the fluid in a short time, the only hope of preventing such compression of the lung as will impair its function lies in the performance of thoracentesis. All the more will the operation be justifiable if the accumulated fluid is interfering with the function of other organs, such as the heart, or is attended with marked embarrassment of the breathing. The chest is punctured in the lateral or posterior regions, and in most eases the greater portion or all of the fluid may be safely drawn off. In general the operation is unattended with danger, although not entirely exempt from such risks as sudden syncope, and therefore not to be undertaken without due vigilance as well as a careful consideration of the individual case and its associa-tions. In many instances not only is the removal of distressing symptoms speedy and complete, but the lung is relieved from pressure in time to enable it to resume its normal function. When there is any evidence that the fluid is purulent the operation should be performed early. In such cases it is sometimes necessary to establish for a time a drainage of the pleural cavity by surgical measures.
The convalescence from pleurisy requires careful tending, and the state of the chest should he inquired into from time to time, in view of the risks of more serious forms of lung disease supervening. (J. O. A.)
The above article was written by: J. O. Affleck, M.D.