A system of practical medicine. By American authors. Vol. 3

by Unknown

Pleurisy is a more prolonged disease, and is not self-limited. The cough of pleurisy is short and quick, with no expectoration, unless it is thin, frothy mucus. In pneumonia the cough is longer, and is accompanied by a tenacious expectoration, more or less free, and generally (not always) tinged with blood. The rusty-colored sputa is almost characteristic of pneumonia. At first there is a marked difference in the dyspnoea in the two diseases. In pleurisy it is superficial, because the lungs are not freely expanded in consequence of the accompanying pain. In pneumonia it is deeper and the oppression is greater. The struggle for breath in the first stage of pneumonia is frequently alarming to witness. The relative frequency of pulse and respiration is more modified in pneumonia. The stitch-like, cutting pain in pleurisy is characteristic and very circumscribed, whereas in pneumonia, unless the pleura is involved, there is little or nothing beyond a dull soreness. We have in pleurisy the restrained movement of the side affected, and corresponding increase of movement of the healthy side. Not so in pneumonia. At the beginning of croupous pneumonia we generally have the crepitant râle heard in inspiration, but not observed in pleurisy. The friction sound, if present, heard in inspiration and expiration, is equally characteristic of pleurisy. If, as sometimes happens, we do not hear either the crepitant râle or the friction sound, we must be cautious in our diagnosis until we have the more definite symptoms of the next stage.

Later on in the clinical course of the diseases, in their second stage—consolidation in pneumonia and effusion in pleurisy—the physical signs enable us to make the differential diagnosis. We expect dulness in both diseases, but it is more absolute in pleuritic effusions, and to the finger, as a pleximeter, the resistance is greater. In pneumonia there is very seldom complete dulness over the whole side of the chest, for there are frequently lobules not consolidated, or spots where the solid deposit has been partially absorbed. Moreover, the area of dulness is not bounded by that peculiar curved line, with its concavity at the base behind, facing the vertebra, gradually becoming convex as it turns upward and forward toward the axilla, again descending toward the sternum, as is the case in pleuritic effusions. Changes of position of the patient may cause the fluid, when in large quantity, in pleurisy, unless prevented by fibrinous adhesions of the two surfaces, to gravitate to a greater or less degree, and thus alter the points where we have flatness on percussion. The enlargement of the thorax, the bulging of the intercostal spaces, the marked displacement of the organs, and the frequently complete obliteration of the semi-lunar space, are characteristic of excessive pleuritic effusions. The displacement of the neighboring organs, especially of the heart, is a very valuable diagnostic sign of pleurisy.

There are, however, other conditions besides the presence of fluid, such as new growths and pneumothorax, which, by increasing the contents of the chest, may produce the same result. We may also meet with cases of congenital malposition of heart or instances where infantile disease, or constrained position, necessitated by occupation, have caused malformation of the contents of the chest.

The most characteristic percussion sign of effusion in pleurisy is the semi-tympanitic (Skodaic) or amphoric resonance high up in front. In rare cases it is found in pneumonia, but it is most pronounced over the consolidated lung, whereas in pleurisy it is above the level of the fluid. The vesicular murmur is not heard below the level of the fluid, unless very feebly at its upper surface, nor indeed is the passage of the tidal column of air up and down the bronchial tubes. In pneumonia bronchial respiration and increased resonance of voice rapidly supervene; whereas in pleurisy the voice is obliterated. In pneumonia we find the characteristic loud, high-pitched, brazen bronchial respiration over the whole of the consolidated portion. When a tubular quality is given to the inspiratory murmur in pleurisy, it is a diffused, distant, and low-pitched sound from the compressed lung. There is a marked contrast between the increased vocal fremitus of pneumonia and its entire absence in pleurisy. In pneumonia there is strong bronchophony with a jarring thrill to the ear, but there is not the displacement of the adjacent organs, the increased volume of the affected side, nor the widening and bulging of the intercostal spaces, with sometimes fluctuations, perceived on auscultatory percussion, as in pleurisy.

Although both diseases are ordinarily unilateral, yet we more frequently meet with double pneumonia than with double pleurisy. It must be borne in mind that we may discover the coexistence of pneumonia and pleurisy. When this does occur special care must be taken in the diagnosis. In cases of pleurisy on the left side, sometimes the impulse of the heart forces the two surfaces of the pleura together, and causes us to hear a pleural, cardiac friction sound. It has the rhythm of the heart, and is heard when respiratory movements have been suspended. This sound is limited to the left border of the heart. Care is needed to prevent the error of diagnosing pericarditis.

The diagnosis of pleurisy from hydrothorax, or passive transudation of fluid into the cavity of the pleura from mechanical causes or blood-poisoning, depends upon the recognition of the fact that ordinarily the latter is not ushered in by fever—that it is bilateral, and is frequently accompanied with dropsy in other parts of the body. Transudations being slowly developed, the lung gradually contracts, and the presence of the fluid is tolerated for a considerable time; indeed, it is not until it is excessive that it compresses the lung. Thus, dyspnoea is not ordinarily produced until the accumulation is very great.

Sometimes the diagnosis between pleurisy and intercostal myalgia, or pleurodynia, is confused and uncertain. The pain may be as intense and the respiration as jerky where there is no pleurisy, if there is great soreness of the muscles between the ribs. The pain is, moreover, accompanied by more or less rise of temperature. Oftentimes the respiration is as painful as in pleurisy, for the individual instinctively refrains from causing the muscles to contract. Usually there is greater tenderness on pressure over the walls of the chest, less fever, and the area of pain is larger in this form of muscular rheumatism. The friction sound, if present, makes the diagnosis clear. We sometimes remain in doubt for twenty-four hours.

Intercostal neuralgia less closely resembles pleurisy. It occurs without fever, generally in anæmic subjects or in those debilitated by chronic general diseases, especially uterine. The tenderness is limited to several points along the course of a nerve, at the exit of the nerve from the spinal cord, in the axillary region, and near the sternum.

Pericardial effusions and aneurisms can ordinarily be readily diagnosed from pleurisies. Their positions in the cavity are so well defined, and the accompanying physical signs are so characteristic, that they ought not to be confounded with pleuritic effusions.

Solid tumors and cysts occupying a considerable portion of the pleura or bulging into it from the mediastinum may deceive us into thinking that there is an effusion. They displace organs, press upon the lungs, or intervene between the lung-texture and the walls of the chest, thus preventing us from hearing the entrance and exit of air and the vibrations of the voice. Not containing air, we have flatness on percussion. Being solid conductors, we have with them increased vocal fremitus, whereas in pleuritic effusions it is not perceived. Ordinarily, tumors are found at the superior or central portion of the chest, and cause an irregular bulging of the walls instead of the general enlargement caused by liquid effusions. Before the discovery of the present modes of physical diagnosis intra-thoracic growths, especially cancerous ones, were frequently confounded with pleurisies by even the most careful observers. Now such errors are only occasionally committed. The history of the case, the general symptoms, absence of fever, etc. will assist us in making the differential diagnosis. A careful examination by physical exploration will give us valuable aids. The bulging produced by malignant growths is not so marked nor is it so uniform. The dulness on percussion is not so pronounced. It does not vary from changes of position of patient. The displacement of heart and other organs is not so marked. Hunt⁵⁰ calls attention to the considerable blood-stained expectoration from cancer. He calls it currant-jelly expectoration. We must look also for the characteristic signs of cancerous cachexia and enlargement of glands in the axilla and in the supra-clavicular fossa. The exploring aspirator-needle will generally enable us to arrive at an accurate diagnosis, with the assistance of a microscope to examine the fluid or solid matter withdrawn. The fluid thus obtained from cancer is generally blood-stained.