The cyclopaedia of practical medicine: comprising treatises on the nature and treatment of diseases, materia medica and therapeutics, medical jurisprudence, etc., etc (Volume 2).

Date:
1849-59
Catalogue details

Licence: Public Domain Mark

Credit: The cyclopaedia of practical medicine: comprising treatises on the nature and treatment of diseases, materia medica and therapeutics, medical jurisprudence, etc., etc (Volume 2). Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

    24/812
    collections of pus which are contained within the sac of the pleura. In practice, however, it is not always easy to determine, a priori, the precise nature of the fluid collected within the chest, as its physical characters are found to vary consider- ably, even in those cases that most closely resem- ble each other in their origin, progress, and symp- toms. In a case of empyema of two months' standing, occasioned by the bursting of a tubercu- lous abscess of the lung into the pleura, the effu- sion, as observed by the writer, presented all the characters of genuine pus ; while in another case, where the pleuritic effusion vs-as produced by a similar cause, and assumed the same chronic form, the operation of paracentesis gave issue to a fluid as transparent and colourless as water. Other varieties, to be presently enumerated, have like- wise been observed in the appearance and compo- sition of these fluids ; and as there are no peculiar symptoms by which we can always discriminate their precise nature during the lifetime of the in- dividual, the term is now generally used without any reference to the puriform character of the effusion. When effusion into the thorax takes place in an individual of a dropsical diathesis, and seems to result from an obstruction to the circulation and the consequent transudation of the serous part of the blood, rather than from any irritation of the secreting surface, the disease is denominated hydrotho7-a.z. When the effusion is known to consist of blood, as in penetrating wounds of the chest, where the pulmonary or intercostal vessels have been injured, the term hccmothorax is used to express it; and the name oipneumothorax is applied when the effusion is of a gaseous nature. With these exceptions, all cases of effusion into the pleura that are sufficient to compress the lung and impede the function of respiration, are com- prehended under the generic appellation of em- pyema. The pleura, like other serous membranes, con- stantly exhales a fluid in the form of vapour, by which its surface is lubricated and moistened. In the natural state, this perspiratory fluid always exists in the form of halitus or vapour; but in a morbid state, it is sometimes exhaled in much larger quantities, and instead of vapour assumes the fluid form. Its qualities are then also mate- rially altered, so that, instead of a slight moisture barely sufficient to facilitate the gliding motion of the opposing surfaces on each other, the serous sac is filled with certain morbid secretions, of which the following are the principal :— 1. Serum: its composition is sometimes the same as that of the blood, and sometimes differs fi-om it in containing a greater or less proportion of albumen. 2. The same combined with a certain quantity o.f the colouring matter of the blood. 3. Pure blood. 4. Pus. 5. The spontaneously coagulable and organiza- Me matter of which false membranes are formed, and which, in their turn, are liable to undergo >arious morbid alterations : thus they may become inflamed and form new false membranes, or exhale blood, or secrete pu*:, melanosis, or tubercle; or iBKtly they may be transformed into fibrous, carti- laginous, or osseous tissue. (^Andral, Anatomic Pathologique.) These morbid productions, either singly or va- riously combined, form the principal, if not the only ingredients in all cases of pleuritic effusion. Our knowledge of the pathology of pleuritic diseases in general, and of empyema in particular, has been considerably advanced of late years by the labours of Laennec, Broussais, and Andral, whose works, {Traite d'Auscultation Mediate, Histoire des Phkgmasies Chroniques, CUnique Medicale,) contain the most complete history we possess of these diseases, and may indeed be said to form a new era in the pathology of this class of affections. The effusion of empyema, it is now generally admitted, is in all cases principally, if not entirely, formed by a morbid secretion from the pleura, and may in almost every instance be referred to in- flammation of that membrane, either in an acute or chronic, an evident or latent form ; and even in those cases where pus or other matter is intro- duced into the pleura from an extrinsic source, as from the rupture of a pulmonary or hepatic ab- scess, the collection of fluid which constitutes the empyema consequent thereon, does not consist so much of the matter of the abscess as of the morbid secretion from the pleura, which the irritation caused by the presence of that matter produces. The nature of the exudation in acute pleuritis and the successive stages of its organization and conversion into false membrane, are detailed in a separate article in this work. (See Pleuritis.) For our present purpose, it is only necessary to consider those morbid secretions of the pleura which evince no disposition to become organized or absorbed, but continue to accumulate in the shut sac of that membrane, where they act as a foreign body, and, by their pressure on the import ant organs contained within the parietes of the chest, present a constant obstacle to the due pei formance of their functions. In some cases the effusion consists of a cleai, transparent, or lemon-coloured serum ; sometimes the effused fluid, though it still retains its trans- parency, contains several flocculi of albumen, some suspended and others precipitated to the bottom. More frequently it is rendered quite turbid by the quantity of these minute flocculi that are partially dissolved and suspended in it, while the pleura, more especially the most dependent portion of it, is co- vered with an inorganic layer of a white or yel- lowish paste formed by these flocculi, which fall in the form of the sediment to the bottom of the fluid in which they were suspended. In other cases, and they are by far the most numerous, the effusion is still more turbid, and of a greyish brown or yellow colour—in short, it exhibits every intermediate variety of appearance until it pre- sents all the characters of genuine t)us. These different varieties of effusion arc some- times mixed up with the contents of abscesses formed in the neighbouring parts, as in the lungs or hver, and discharged into the pleura. In some cases the effusion is coloured bv the admixture of a certain quantity of blood, and in some rare in- stances the eflusion has been found to consist en- tirely of blood. This sanguinolent effusion some- times occurs at the very onset of the pleuritic at-