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

by Unknown

⁴⁴ Consumption and Dis. of Lungs and Pleura, 1878.

Above the level of the fluid, and again as absorption of fluid takes place, we have a return of the characteristic friction sound as the muscles of the chest recover their normal power. With care this sound will not be confounded with intra-pulmonary râles, which are moist sounds removed or modified by cough or expectoration. These convey to the ear the sound of bubbles of air as they pass through the mucus and the secretions of the bronchi; whereas the friction sounds are superficial noises from rough surfaces moving over each other. The mucous râles which are sometimes heard are not from the pleurisy, but from bronchial catarrh. The friction sounds heard in the stage of absorption are ordinarily coarser and more abrupt. They are unequally jerking in character, and in quality resemble osseous crepitation. In chronic pleurisy, and for a long time after the fluid is gone in acute pleurisies, we have pleuritic rubbing sounds when the walls of the chest are drawn out in full respiration. At the absorption stage we ordinarily hear the lung gradually expanding. The respiratory sounds are feeble, and frequently moist subcrepitant râles are heard in the bronchial tubes. If the effusion has been of long duration, we find the pleural surfaces so thoroughly coated with fibrinous deposit, and the lung so separated by bands from the costal pleura, that the expansion of the lung is very much impaired and the percussion dulness does not subside. Leaming and Camman of New York give numerous cases where there might well be difference of opinion as to whether the signs heard were intra-pulmonary or pleuritic. In cases where the intra-pulmonary adventitious râles resemble the extra-pulmonary frictions, the diagnosis is assisted by considering the length of the sound. The character and intensity of the friction murmur varies very much. It may be a slight grazing sound or a coarse, sharp creaking-of-leather noise. Walshe gives no less than six modifications of the friction sound, ranging from a feeble, scarcely audible noise to one of extreme loudness. Friction sound is mostly an isolated phenomenon—that is, it is not accompanied by any unnatural quality of respiratory or vocal sound. Advanced type friction consists of a series of jerking sounds, rarely exceeding three or four in number.

We must remember that sometimes, notwithstanding a considerable quantity of fluid, the lung expands, and, pushing the fluid aside, causes the rubbing of the pleural surfaces together. When unmistakable, these respiratory friction phenomena are pathognomonic of the results of pleurisy. Thus they are properly considered of great value in the diagnosis.

Pneumo-pericardial Friction Sounds.—On the left side the uneven pleural surfaces are sometimes forced together by the impulse of the heart; of course, the resulting friction sounds are cardiac in their rhythm. Then, again, fibrinous deposits on the outer surface of the pericardium are forced against those of the covering pleural layers, both by respiratory and heart impulses. Close attention to the rhythm and the positions where these sounds are heard will prevent their being considered pericardial in their nature.

The fluid may be nearly removed and yet the condensation of the superficial strata be sufficient to produce extensive and marked dulness. Under such circumstances the production of friction phenomena is inevitable. The retention of some portion of the lung surface in tolerably close proximity to the costal pleura by means of adhesions also renders the production of friction sound possible, although a considerable quantity of fluid be present in the pleura. It is common to find effusion signs in the back and friction signs in front. We most frequently have friction at the base when there is absolute flatness. If the walls be separated by fluid, there can be no friction from contact. But it rarely happens that the fluid rises between the surfaces. To produce friction sounds we must have motion of rough surfaces which are in contact.

If the patient talks while we are listening in cases of small effusion we hear over the scapula, toward the spine, and between the scapula and the spine, bronchophony, as we do also when the lung is nearly deprived of air, in which case the sound sometimes has the bleating, nasal resonance designated by Laennec ægophony. In his opinion this was of constant occurrence and of great diagnostic value, but now it has been demonstrated that this sound can be heard when there is no fluid whatever, but consolidated lung. Anstie calls it one of the fancy signs of pleurisy. Ægophony is an unimportant variety of bronchophony, and not a characteristic phenomenon of pleuritic effusions. Of itself, it is not diagnostic of effusion, yet it is none the less true that it is a modification of bronchophony, and is commonly met with in cases of moderate pleuritic effusion, usually toward the upper margin of the fluid. It is difficult to state definitely the amount of fluid which usually produces it. Guttman thinks it is probably produced by the vibration of the walls of the flattened, compressed bronchi; this vibration is excited by the voice and transmitted to the thin layer of fluid which, at the upper part of the exudation, lies between the lung and the chest-wall. This tremulous movement of the sides of the bronchi gives the voice sounds a quavering, interrupted character; and, as they have to pass through a fluid medium to reach the surface, they lose in clearness and precision and acquire a nasal twang.

When the effusion is large, and we have full dilatation of the chest, all vocal resonance ceases, because the vocal vibrations go through media of such different kinds that they are lost before they reach the ear. During absorption, before the lung recovers its normal volume, we again hear bronchophony. Pleural adhesions and thickening cause the sound to be heard through the effusion when we least expect it. It is not unusual to find ægophony and bronchophony in the same lung. They are also found in some cases of pneumonia, and in some individuals, especially in children, we have between the scapula a normal resonance of the voice, with an ægophonic resonance.

Bacelli's Sign (Pectoriloquie aphonique).—This, the reverberation of the whispered voice through the fluid, is a sign of considerable value. If well marked it indicates fibro-serous fluid; its absence, however, does not show that the fluid is not of this character. (See [Purulent Pleurisy].)

Auscultation is of great value as indicating with definiteness the position occupied by the effusion as it is being reabsorbed.

Heart Murmur.—From excessive accumulation of fluid in the pleural sac a systolic murmur over the base of the heart is very often heard. That it is produced by pressure or twisting of the aorta is evident from the fact that it ceases when the fluid is withdrawn.