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:
- 1845
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.)
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![the circulation, only a small proportion of the blood contained in their circulating system, (An- dral, Op. cit.) Besides these, which may be considered as the physiological causes of pulmonary emphysema, there are others which produce a similar condi- tion of the organ in a manner purely mechanical, by keeping the air-cells in a state of over-disten- sion. Amongst these may be enumerated violent efforts of any kind (especially if often renewed) which cause the long-continued retention of the breath; repeated attacks of catarrh, bronchitis, asthma, or other diseases of the lungs or air-tubes, attended with difficulty of breathing, or distress- ing paroxysms of coughing. The mechanism of the over-distension and rup- ture of the air-cells in these cases may be explain- ed by the efforts which are constantly made by the powerful muscles of inspiration to introduce a fresh supply of air into the air-cells, while that which they contain is prevented from escaping by pellets of viscid mucus, spasmodic stricture of the bronchi, or turgescence of the bronchial mem- brane, according to the nature of the disease which produced the dyspnoea. In this way, the air-cells are kept in a state of over-distension which the efforts that are made to evacuate them only tend to conhrm and increase ; and provided the obstruction is of some continuance, the dilated condition of the cells will be rendered permanent, or else their parietes will give way, and allow sev- eral cells to be thrown into one. From this view of the matter, it will readily be understood why all diseases accompanied by pro- tracted attacks of dyspnoea, or violent and often repeated paroxysms of coughing, are so constantly followed by emphysema, especially when occur- ring in persons advanced in life, in whom, as we have already explained, the lungs are peculiarly predisposed to this disease by the atrophy which their parenchymatous texture naturally undergoes at this period of life. But though the over-dis- tension and rupture of the air-cells is in general a slow process produced by long-repeated efforts to overcome an obstruction to the free exit of their contents, and is consequently the result, in most cases, of some chronic affections of the bronchial tubes, such as dry catarrh, asthma, or the congest- ed state of the mucous membrane, so frequently produced by organic lesions of the heart; it may likewise be produced in a very short space of time, when the efforts made by the muscles of respira- tion are violent and constantly repeated. We have frequently found the lungs emphysematous in children dying of hooping-cough; and in one instance, where the hooping-cough had not last- ed longer than three weeks, we saw several cells dilated to the size of garden-peas, of a globular form, and with their parietes evidently hypertro- phied. [The disease is considered by some to be the result of bronchitis—the mucous secretion of which cannot readily be expectorated, and there- fore dilates the vesicles; but this is denied by M. Louis, because, in the cases which he observed, the emphysema was rarely preceded by bronchi- tis, and the bronchial tubes, in the vicinity of the dilated vesicles, were found empty, containing neither mucus nor false membrane. A recent writer, Dr. G. Budd, ascribes it to a want of elas- ticity of the lung, or, in other words, to absence of its natural tendency to collapse. The power- ful muscles of inspiration are continually acting to dilate the chest, and thence, by virtue of atmos- pheric pressure, the air-cells. This agency is not counteracted, as it should be, by the natural elas- ticity of the lung, and the air-cells, as well as the cavity of the chest, are, in consequence, perma- nently dilated. The question as to its hereditary nature was closely and ably investigated by the late Dr. J. Jackson, Jun., of Boston, who attained the fol- lowing results. First. Of twenty-eight patients, affected with pulmonary emphysema, eighteen were the offspring of parents, one of whom had been attacked with the same affection, and several of whom had died in the course of it. In some cases, the same was true of the brothers and sis- ters. Secondly. Of fifty individuals, not affected with emphysema, three only were descended of parents who laboured under the disease; whence it would follow, that emphysema is frequently an hereditary affection. It would appear, too, that hereditary influence is much more marked, where the emphysema dates from early infancy, than in those in whom it commences immediately before, or subsequently to the age of twenty.] From.whatever cause the emphysema proceeds, its constant effect is to render the portion of lung affected incapable of perfonning its respiratory functions, as is evident from the absence of respi- ratory murmur in the part during life, and the difficulty with which the air escapes from the overstrained or ruptured cells, even after the lung has been removed from the body. Moreover, as the emphysema is in almost every instance origin- ally produced by turgescence of the bronchial membrane, or spasm of the circular fibres, so from an effect it generally becomes a cause, and main- tains the disease by which it was originally ex- cited. Accordingly we find that persons labour- ing under emphysema of the lung are particularly liable to attacks of asthma and bronchitis, and, as a consequence of the latter, and of the efforts made during respiration, to hypertrophy or dilata- tion of the heart. These intercurrent diseases usually occur only after long intervals during the first years of the disease ; but when the complaint is of long standing, and the patient is far advanc- ed in life, the paroxysms become more frequent and more severe, each succeeding attack increases the extent of the organic lesions and rupture of the pulmonary tissues, and sometimes interlobular emphysema then ensues. From these observations it may be concluded that pulmonary emphysema in a moderate degree is not a disease of great severity, and that the principal danger is to be apprehended from the repeated attacks of bronchial disease by which the emphysematous condition of the lung was origi- nally produced, and to which, in its turn, it seems to act as a predisposing cause. From the pathology of emphysema, its diag- nosis and treatment may be easily deduced. The dyspncea, which is its most constant symptom, depends in a great measure on the extent of the disease, and the age and constitution of the indi- vidual. When the emphysema is rapidly formed,](https://iiif.wellcomecollection.org/image/b21116775_0019.jp2/full/800%2C/0/default.jpg)
