CHAPTER II. CONFORMATION OF CIEST—CIRCUMSTANCES INFLUENCING IT— (Part 1)

CHAPTER II. CONFORMATION OF CIEST—CIRCUMSTANCES INFLUENCING IT— MODE OF EXAMINATION—MENSURATION—SUCCUSSION. Iv was my object in the first chapter to prevent a frequent source of error, which often produces either an obvious or a concealed influence upon the mind. ‘This is a desire to lay too much stress upon a single set of symptoms, to the neglect of others, and to examine a disease of a part of the body as if it were nearly or altogether unconnected with the same, or with different disorders which attack other organs and tissues. In commencing, therefore, a course of studies which are founded upon the positive evidence of anatomical lesions, and of the cor- responding physical signs, I would put the reader upon his guard against too anatomical, a view of the subject, too exclusive a study of lesions, and would warn him against allowing the results of disease to be confounded with disease itself; or the physical signs. which constitute the key to so many important researches, from being mistaken for actual diagnosis. It is the deductions from the whole of the physical signs and functional symptoms, which constitute the diagnosis; not the naked examination of a single set of them. This may seem a matter which is too trivial to attract much notice; but in practice it is of much moment, and the errors which I have scen from a neglect of it are frequent, and very readily committed. It may seem that this is reasoning against myself, as it were, and attacking the subject upon which Tlay so much stress; but, in professing to give an essay on diagnosis and treatment, imperfect as it is, I am necessarily led to an enlarged study of pathology, and to the view of the subject which seems to me most consistent with facts,—that is, one embracing the relation of the phenomena one to another. Tam also unwilling to diminish the value of positive observa- 28 CONFORMATION OF THE CHEST. tion, by drawing any inferences which the actual state of the subject will not fully warrant; this would be the case, if, at the commencement of our studies, we fall into a contracted, imper- feet mode of reasoning. After giving this warning against the abuse of the physical signs, I may proceed to point out the best method of avoiding or overcoming the difficulties which we mect with, at the com- mencement of our studies. They depend ina great degree upon the difficulty of finding fixed starting points, from which the study of the subject may begin. If we could acquire distinct ideas of the sounds of the chest from description, the difficulty would in a great degree cease, but this requires much care and attention, but by a little effort on the part of a physician who is interested in the subject, we believe that most of the difficulties may be obviated. To aid him, it is, therefore, necessary to explain fully the best mode of learning the sounds,—that is, of acquiring a suflicient number of sounds to serve as a point of departure, and guide for subse- quent study. This method supposes that the sounds are ana- lysed and separated into their elements, and requires at first more than an ordinary share of attention: but the whole time required for learning the art is much shortened, and the subject greatly simplified Most of these initial sounds may be discovered in the healthy body,—that i is, sounds sufficiently similar to those we meet with ase, to enable us to recognise them when they are heard ; and if these are thoroughly learned, the remaining sounds, which are the most easy, are quickly acquired. We will find it to our advantage therefore, to follow very nearly the process which I shall point out, for the purpose of simplifying those‘sounds ; for although it is not indispensably necessary for us, it is highly useful, and really will shorten the time and attention required in their study. In studying the physical signs, I follow as nearly as possible the most natural method, reserving to myself, however, the privilege of deviating from it as often as may be advisable. The physical signs, properly speaking, may be classed under the heads of alteration in the conformation of the thorax, and of CONFORMATION OF THE CHEST. pr) the resonance of the chest on percussion, and the sounds yielded by respiration, or produced during the act of coughing or speak- ing. These constitute the signs which may be regarded as strictly physical. There are some other signs, which, although less important, are, to a certain extent, classed among the phy- sical signs; they belong more properly to the conformation of the thorax, than to any other division: under this head I shall treat of them. These are, suceussion, or giving to the patient a sudden shake, to ascertain the presence of air and liquid in the cavity of the pleura, which is rarely practised, and is, in the majority of cases, both totally unnecessary and highly disagree- able to the patient; palpitation, or examining the chest by placing the hands upon it, and pressing them carefully along the lateral portions of it. CONFORMATION OF THE THORAX. The thorax, it is well known, resembles an irregular truncated cone. It is flattened on each side, and presents numerous in- equalities, depressed in one part,-and elevated in another. For the convenience of study, it is usual to examine it anteriorly, posteriorly, and laterally. Of these surfaces, the lateral, or the axillary, are the most regular,—the posterior, the least so. The walls of the thorax do not represent precisely the space occu- pied by the lungs and heart ; for the liver, spleen, and stomach, encroach slightly upon the lower part of the cavity. This is par- ticularly the case with the liver, which rises on the posterior part of the right side of the chest, nearly half an inch higher than the corresponding boundary on the leftside. On the whole, the lower boundary of the right side may be represented by aline drawn from the spinous process of the twelfth dorsal vertebra, to the lower bone of the sternum: on the left side, the boundary begins also at the twelfth dorsal vertebra, but passes at a distance of half, or at least one-third of an inch higher, until it reaches the precordial region. The lower boundary of the chest, as thus defined, is not always the same, as the size of the liver is of course variable, and the dimensions of the thorax are necessarily influenced by this circumstance. This line is not followed with 30 CONFORMATION OF THE CHEST. perfect regularity, especially on the left side where the heart passes a little beyond the limit of the adjoining part of the chest. At the upper boundary, the difference of the two sides is less; on the right it sometimes rises a little higher than upon the left, from the greater development of the muscles and bony parietes of the thorax on that side; but this difference is, in general, so slightly marked, as scarcely to attract attention. ‘The lungs extend a little beyond the clavicles, especially during the act of full inspiration, but to a distance not exceeding half anineh. At the posterior part of the chest, the upper boundary is formed by a line drawn from the upper dorsal vertebra, outwards and down- wards towards the point of the shoulder. When the conformation of the thorax is perfeetly normal, it presents an irregular plane on each of its four sides; but the angles of these planes are sufficiently rounded to retain a general conoidal shape. Each side of it offers several clevations and depressions ; at the anterior part these correspond with pecu- liaritics of form of the viseera, and are really formed by the parictes of the chest; but the irregularities of form at the pos- terior surface are owing, in great part, to the muscles, to the spine, and to the seapule. The elavicles form a ridge, which is slightly arched; the space above them is therefore depressed, exeept the patient be extremely corpulent, or labour under cer- tain diseases of the lung or pleura. Beneath the clayicle, another depression, but one much shallower, exists; it extends to the lower part of the second rib. The space below this depression is slightly and regularly convex as far as the upper edge of the liver; at that level there is, in many persons, on the right side, a slightly depressed line, which corresponds with the interval between the liver and the lungs. On the left side in young persons, there is often a prominence corresponding to the heart; this is slightly marked, and never decided, as it is in cases of real disease of this organ, or effusions within its investing membrane. The lateral portions of the chest are regularly bulging from the apex to the base; and as the walls are here thinner than elsewhere, and nearly without muscles, the external form cor- responds nearly to the lungs. CONFORMATION OF THE CHEST. 31 The posterior surface is rendered irregular by the scapulz ; but at the part uncovered by these bones its form is nearly as regular as that of the other portions, gradually widening towards the base of the chest. A slight depression, or gutter, exists on each side of the spine, for the reception of the dorsal muscles, The lower and posterior portions are often dilated from effusion into the pleura, and yield to the pressure of liquid from within » with great readiness. The upper part is not changed in confor- mation, except the quantity of liquid be very large. “The con- traction of the chést is also extremely obvious at the lower por- tion after the absorption of pleuritic effusions. In children the form of the chest is much more rounded than in adults; and in women, although the exterior seems more irregular than in males, yet the proper bony parietes are much more regularly formed, and are more conoidal in shape. The conformation of the chest, it is well known, is often cha- racterized by individual peculiarities. Thus, some individuals are called chicken-breasted, from the prominence of the sternum, and others present a well-marked depression at the lower por- tion.of this bone, which is sometimes congenital, and at other times is caused by trades or occupations which oblige the fol- lowers of them to work in a constrained posture, leaning for- wards; this is particularly the case with shoemakers, who nearly all present this depression after working at their trade for a few years. Other individuals who are thin, and of a feeble consti- tution, offer a remarkable contraction of the’ parietes of the chest; but in all these cases, the contraction is more or less general, instead of being confined to a single part of the chest. When it depends upon disease it is much more local, and is caused in nearly every instance by pleuritic adhesions, which draw the walls of the chest towards the lungs. Enlargement of the chest, beyond the natural average, is nearly as frequent as contraction. When it coincides with a general development. of the body, and evidently depends upon a stout and large frame, it is of course indicative of health, rather than disease. The morbid dilatations, properly so called, are local, either limited to a part, or to the whole of one side of the chest; on this account they are readily recognised. They depend either 32 CONFORMATION OF THE CHEST. upon an anormal development of the internal organs, or upon dilatations caused by effusions of air or liquid into the serous cavities of the chest. The comparison of the two sides is re- quisite, in order to recognise dilatations or contractions of the chest: and the thorax must be examined throughout in nearly every position, so that its true and relative dimensions may be ascertained. It is not necessary that the chest should be exposed in order to examine its conformation, although this is much more con- venient than to inspect it when covered. When no objection exists to exposing the chest, the patient should be placed in a sitting posture, or remain erect; if that be impossible, he should lie upon his back, and quite straight, so that the light may fall upon his chest; a cross light may of course give rise to error. The patient should then remain at rest, with his arms lying quietly by his sides or slightly crossed, if the posterior part of his chest be examined: in this way the whole of the anterior or posterior surface may be taken in at a glance. An examination of this kind is, of course, not practicable, in cases of women, or of patients who are sweating profusely; under such cireum- stances, we must content ourselves with the partial inspection, which is practicable when the body is more or less covered by clothing, and we may aid in this examination by passing the hands lightly over the thorax. For in most cases this mode of examination is amply sufficient for the purpose, and is free from the disagreeable circumstances which attend the exposure of the person. The examination by the touch is especially convenient for the posterior and lateral parts of the chest, where the morbid dilatation is generally most considerable. The examination by the touch is called palpation, but I do not think it at all necessary to multiply terms in the description of the methods of physical examination. Palpation, then, is nothing more than the examination of the chest by means of the touch, it aids the sight, and often may be substituted for it when the patient is too thickly covered. The hand forms, as it were, a kind of natural callipers, and will give very accurate results. If we examine the lateral and inferior portions of the chest, we may place the whole palmar surface of the hand upon it; if the CONFORMATION OF THE CHEST. 33 anterior and upper portions be examined, the fingers may be passed lightly over it. In this way we can detect any abrupt deviations from the natural conformation, but a general and moderate rise or depression can scarcely be detected except by the sight. If we cannot resort to this means of investigation, we must content ourselves with the other physical signs. Dilatation of the chest is necessarily produced by all diseases which give rise to enlargement of the pulmonary vesicles, or to distension of the pleure. Those which act upon the pleure: are inflammation—the products of which are serum, lymph, and purulent matter ;—or dropsy, in which the secreted fluid consists merely of serum. The effusions arising from pleurisy are nearly always confined to one side of the chest, take place rapidly, and are much more local than those of hydrothorax, which extend over a large surface, and are not confined to a single lung. Hence, the pleuritic distension begins chiefly at the base of the lung, and extends upwards, involving the whole of one side only in those cases in which the quantity is extremely great. Peri- carditis gives rise to dilatation from the same cause as pleurisy, and the prominence follows very nearly the shape of the peri- cardium, and is therefore somewhat triangular, the small ex- tremity pointing upwards. The extreme dilatation which takes place in severe cases of pleurisy, in which the whole side of the chest is enlarged, elevates the shoulder, and gives the whole body an inclination towards the healthy side. This is often evi- dent when the patient walks or sits in the erect posture. The effusions of liquid into the serous membranes give rise to the most decided, and, as it were, abrupt prominence of the chest; while the dilatation produced by enlarged vesicles is, in general, less decided, or, at least, more gradual. It gives rise to a more equable and moderate bulging of the chest, than that from effu- sions of liquid into the serous cavities. Of course it is most marked near those parts of the lung where the vesicles are most frequently dilated—that is, along the anterior portion of the chest, on each side of the sternum; but, if it involve a large portion of the lungs the shoulders are sometimes elevated, and the space above the clavicles becomes prominent, instead of offering a slight depression, as it does in the natural state. 3 : 34 MENSURATION. Contraction of the thorax is a consequence of many diseases in which pleurisy has oceurred, cither as a primary or secondary lesion; but it is most marked in cases of primary pleurisy, espe- cially where the quantity of effused liquid has been large. In the secondary pleurisy whieh follows or accompanies phthisis, contraction almost invariably takes place, and usually occurs near the summit of the lungs, so that the natural depressions, both above and below the clavicle, are exaggerated. Some- times the depression reaches to the lower portions of the lung, as in ordinary pleurisy. The latter variety usually follows those cases of phthisical pleurisy which have commenced in the ordi- nary way, and in which the development of tubercles takes place rather late in the disease, after the inflammation has ceased, or at least has diminished. The general rule holds good, that contraction is evidence of previous pleurisy,—the exceptions are nearly all of a doubtful nature. In a few rare cases the tissue of the lung contracts from the partial or com- plete cicatrization of a cavity, perhaps from inflammation, although the attendant pleurisy may not be sufficiently exten- sive, or the adhesions strong enough to account for the depres- sion. In these eases we are bound to admit that the pressure of the atmosphere has filled up the vacuum which would other- wise have been left. In the depression which follows pleurisy, it is true that the process is somewhat similar, as I shall show when speaking of this