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

by Unknown

⁵⁰ Loc. cit.

Inflammations of the pleuræ are sometimes caused by the presence of intra-thoracic tumors. Abscesses of the liver and echinococci cysts may ascend, and, pushing the diaphragm before them, occupy the pleural sacs, and thus simulate pleuritic effusions.

Pulmonary atelectasis, caseous inflammation of the tissue of the lung, aneurisms of the large thoracic blood-vessels, may, without care, be mistaken for pleurisies. It is very important to ascertain the nature of the fluid effused into the pleural cavity, whether or not it is serous, sero-fibrinous, purulent, or hemorrhagic. Generally this can be done by careful study of the accompanying general symptoms and the clinical history of the case. If there are repeated irregular rigors from the beginning, followed by high fever and free perspirations, there is every reason to fear that the fluid is purulent. If symptoms of blood-poisoning develop, we are still more confident that there is pus. Its hemorrhagic character may be inferred when great pallor, weakness, and lowered temperature suddenly appear during an acute attack.

Bacelli's physical sign known as pectoriloquie aphonique, or the passage through the effused fluid of the whispered voice, has considerable significance as a means of testing the nature and character of the fluid. His conclusion was that, when heard, it showed the fluid was fibro-serous; when not heard, it revealed to us that the effusion was purulent or sero-purulent. Laennec had noticed that in voiceless consumptives the whispers would sometimes resound as if the patient shouted in the ear of the auscultator. R. Douglass Powell reported⁵¹ 10 cases bearing upon the value of this sign. In 6 of these, in which the fluid was clear, 5 yielded the sign, the sixth did not. In 2 acute cases, when the effusion was purulent, the sign was heard. He adds that he has heard the sign to perfection in fetid sero-purulent effusion. Mercadie⁵² claims that when pectoriloquie aphonique is heard in purulent effusions it is only at the uppermost part of the fluid near its limit, where it has become very thin from the weightier portion, the flocculi, and the leucocytes falling to the dependent portion of the sac. Care must be taken in listening for this sign. The patient must be ordered to speak each syllable slowly and in a whisper, distinctly counting up to twenty or thirty. If it be present we ought to be able to perceive that the syllables sound, to the ear, clearly articulated along the height of the effusion. The sound is caused by the transmission of the whisper without any buzzing and without continuous murmur. The maximum of intensity of this sound is heard along the vertebral gutters and along the posterior base of the pleural cavity. It becomes feeble in its distinctive character as we approach the axillary region and also immediately under the angle of the scapula. The theoretical objection has been made to this sign that its production is contrary to well-known physical laws of the conduction of sound-waves. It is said because the sound originates in the air it must be indifferently conducted by fluid; moreover, that its transmission ought to be in proportion to the density of the fluid, whereas this sound is best conducted by a thin fluid. Walshe's explanation of the greatly-increased sound-conducting power of a consolidated lung in croupous pneumonia was that it was owing to its homogeneity of structure. Bacelli avails himself of this principle to account for our hearing through a fibro-serous fluid the whispered sonorous waves, and our not hearing them when the fluid was sero-purulent or purulent. In the latter case the fluid is excessively heterogeneous, containing leucocytes in abundance, besides layers of membranes, flocculi, and blood-discs. The sound-waves are lost as they pass through these media of different density. We have found it to be a physical sign of value in the differential diagnosis of the nature of the fluid, yet its presence is not pathognomonic of serous effusions. In thin fluids it is generally heard, and ordinarily it is not found in purulent pleurisies. If well marked, it indicates a fibro-serous effusion. Its absence does not necessarily show purulent pleurisy. Its greatest value is as indicating the purulent transformation of a fibro-serous effusion.

⁵¹ Trans. Int. Med. Cong., 1881, vol. ii.

⁵² Thèse de Paris, 1876.

Thanks to modern investigations, we have in the very fine needle of the aspirator, or that of the hypodermic syringe, a delicate and sure means of accurate diagnosis, not only as to the nature of the fluids, but as to that of tumors and growths which may be confounded with them. We would not use for exploration a trocar and canula. We consider it best to employ a short needle in aspiration, for fear that a delicate hypodermic needle might break. Flint states that he has known several instances of this accident. Aspiration can be performed with perfect safety, and, indeed, without any fears of unpleasant results even if we perforate an aneurism. The orifice made is so small that the tissues close the moment the needle is withdrawn after making the exploratory puncture. If care be taken to cleanse the instrument and to use Listerism that no deleterious germ be introduced, the operation is harmless. (See [Purulent Pleurisy].)

Blunders in diagnosis, however, will rarely occur if an examination is conducted with great accuracy, and if we follow the course of the disease with care.

PROGNOSIS.—The prognosis of simple primary pleurisy is generally favorable, unless it is complicated with other diseases or occurs in enfeebled persons. The intrinsic tendency of the disease is to recovery. Laennec considered that the prognosis in acute pleurisy was always favorable. Pleurisy with scanty sero-fibrinous effusion is not in itself serious. Dry pleurisy is free from danger. Subacute pleurisy with large effusions, where the course of the disease is insidious and slow, is more apt to be followed by tuberculosis than the more acute cases. Louis's law, deduced from 150 cases, that patients never died from the effusion in acute pleurisies, was long since disproved by Trousseau. Lacaze du Thiers published in 1873, in his thesis, a number of cases of sudden death from large accumulation of fluid. These deaths were caused by a large amount of effusion being thrown out rapidly, and suddenly compressing the lung before the system had time to accommodate itself to the presence of the effusion. These cases, termed foudroyant, should be very carefully watched. There is danger of death from orthopnoea when the pleural cavity is completely filled, especially in latent pleurisies, where the patient, unaware of the risk, makes, perhaps, unusual physical exertions. Some deaths have been caused by oedema of the lungs and some by syncope; others, again, from thrombosis of the pulmonary artery. We must bear in mind the grave prognostic value of attacks of orthopnoea and severe dyspnoea, because they, more than the mere quantity of the fluid, show the want of tolerance in the organism. These cases demand prompt mechanical interference with the aspirator. The very rapid accumulation of the effused liquid, even if unattended by dyspnoea, is an unfavorable sign, for observation has proved that in such a case its absorption is attended with more difficulty. Bilateral pleurisies attended with considerable effusion are commonly fatal.

If there are complications with other acute diseases, such as pericarditis or pneumonia, the prognosis may be far from favorable, more particularly if pleurisies supervene when the organism has been exhausted by a long continuance of the primary disease.