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

by Unknown

²⁷ Ziemssen's Supplement.

²⁸ Wien. med. Wochenschr., 1878, quoted by Garland.

²⁹ "Ein Beitrag zur phy. Diag. der Pleur.," Berlin klin. Wochenschrift, 1878, No. xii.

Although the fluid first collects over the posterior portion of the diaphragm, flatness on percussion is first observed over the axillary portion of the diaphragm, because, as explained by Calvin Ellis, the conditions there are more favorable for percussion. As the effusion increases the line of flatness, when the patient is in the upright position, advances, not directly up the back and horizontally across the chest, as was formerly supposed, but across the back in a curve reaching its highest point in the axilla, from which it descends toward the sternum.³⁰ R. Douglass Powell³¹ says the upper margin of the effusion in typical cases is not a water-level, but presents a curve having its convexity upward and in the lateral region. Since the attention of the author was first called to a careful examination of the curve of flatness as ascertained by light and delicate percussion (in the erect position), he has found it to be more or less of an Ellis curve at an early stage of the effusion. The line is sometimes better defined than at others. All observers, however, must acknowledge that at the stage of the disease when cases of chronic fibro-serous pleurisy are first seen the letter S curve is not well marked. Mason states that although in some of his 200 cases this peculiarity was observed, in others the line was horizontal. When fluid fills the chest to excess and overcomes the elasticity of the lung, it gives flatness on percussion high up, even to the clavicle, and behind to the supra-spinous fossa. The fluid filling the cavity, the line of flatness becomes nearly horizontal. Then it is that percussion reveals the displacement of the diaphragm and abdominal organs. On removing the excess of fluid by aspiration or by absorption, this curved line reappears, and continues as previously.

³⁰ See section on Pathological Anatomy of Pleurisy, distribution line.

³¹ London Med. Times and Gazette, Oct., 1882.

Contrary to the general belief, when the fluid is moderate in quantity change of position of the patient modifies but little the area of flatness, owing to its being retained between the lung and diaphragm. Woillez³² noticed slight mobility (never more than to the extent of one intercostal space) only in 5 of his 82 cases. He concluded that the conditions were very different from what they were in ordinary vessels outside the body. Woillez does not attempt to explain what these conditions are. Skoda acknowledged that in the majority of cases the fluid does not change its position as the patient moves. Skoda and Wintrich attribute the non-movement of fluid to adhesions. Garland, and subsequently W. H. Stone and Douglass Powell, showed that the effusions were immovable when in moderate amounts, because they were kept so by the retractility of the lung, and that the large amounts were movable because the retractility had been overcome by them. When in large quantities the fluid accumulates in depending positions of the chest. Later on in the disease, adhesions and bands mechanically interfere with the line of flatness; or if there be any disease of the lung interfering with its retractive force, the fluid may not take its usual line. These peripheral adhesions frequently occur at the upper margin, and are sometimes wavy and irregular. They often occur early in the disease, and prevent in a marked degree the fluid from yielding to the negative lung-traction.

³² Mal. Aigues des Org. Resp., Paris, 1872.

By these bands the pleuritic fluids become sacculated in different parts of the thorax—between the lungs and the walls of the chest, between the diaphragm and lungs and the pericardium, the mediastinum, the vertebral column, and actually between the lobes of the lung. Fraentzel holds that the percussion sound is dull over the thorax whenever the effusion attains the depth of from one inch and a half to two inches between the lung and the chest wall. Garland by his experiments on dogs shows that the fluid does not thus rise between the lung and parietes, except a very thin layer, by capillary attraction, not sufficient to cause flatness on percussion or to interfere with the expansion of the lung unless the amount is very excessive, and not until the lifting power of the lung is completely overpowered. When the effusion is very large, it fills up the posterior portion of the thorax, compressing the lung against the uppermost portion of the spine or the mediastinum. The percussion sound is absolutely flat, provided the force of the blow be not too great; in that case the ribs are thrown into vibration or the vibrations extend to the sound lung. This materially impairs the dulness and may lead to error of diagnosis.

The lung may be prevented from contracting by reason of various kinds of adhesions or by means of widespread infiltrations, by emphysema, and by laryngeal stenosis. In such cases, as the effusion increases, it quickly rises in the thinner layers without displacing the organs. Fraentzel warns us that sometimes, in left-sided effusions, the lung having become adherent to the heart, the heart is drawn back with the lung away from the wall of the chest, and then it cannot be felt anywhere: the absence of the apex-beat and the feebleness of the heart-sounds may lead us to assume, incorrectly, that there is effusion in the pericardium. If the fluid collects between the external layer of the pericardium and the mediastinum, the heart is surrounded and pressed by the pleuritic effusion.