Part 3

PART FIRST.

OF INFLAMMATION.

There are few accidents or diseases, to which the human body is liable, which are not preceded or followed by incited action, increased circulation, and accumulation of blood in the capillary vessels of the part affected; and these phenomena require to be very attentively studied, and correctly understood, by all who propose practising the healing art. As all the salutary as well as diseased processes which occur in the human body are more or less attended or affected by this action, and as its regulation forms a principal part of the duty of the surgical practitioner, this work cannot be more properly commenced than by treating of its nature, consequences, and management.

Inflammation may be defined to be, an unnatural or perverted action of the capillary blood vessels of an organ or part of the body, attended with redness, throbbing, swelling, pain, heat, and disorder of function, as well as with more or less disturbance of the system.

Every part of the body is liable to inflammation; and some writers have divided this action into different kinds, according to the particular tissue which it chiefly involves. But it appears to be always of the same character, though modified by various circumstances, such as the tissue in which it occurs, the state of the constitution, the exciting cause, and the intensity of the action.

The usual division of the subject, into Acute and Chronic, is that which it is here proposed to adopt. The term Chronic Inflammation is more properly applicable to a consequence of the Acute: but it is at the same time true, that morbid actions proceed more slowly in some constitutions, and in some parts of the body, than in others; and that changes of structure and morbid products, such as generally result from inflammatory action, even occasionally occur, without the prominent symptoms of inflammation being experienced by the patient or detected by the practitioner.

The term Morbid is used in contradistinction to what is called Healthy Inflammation; but inflammatory action is generally connected, more or less, with a diseased or disordered state of some part of the body. In many circumstances it is highly necessary that a certain degree of incited action of the vessels should occur, and continue for a certain time; as during the uniting of fractures, the adhesion of wounds, and the healing of some sores—and thus far it is healthful: when, however, the action becomes excessive, it must, for this reason, be considered morbid, as it frustrates the natural reparative process; if the action, in fact, proceeds farther than is necessary for reparation, it becomes a disease, and leads to absorption or destruction of parts. In animals possessing the greatest powers of reparation, inflammation, it appears, does not take place at all, or is very slight, and scarcely ever proceeds to suppuration.

Redness is the first sign of inflammation to be considered; this is observed, in the living body, on the surface, or at the extremities of those canals which terminate externally. The inflamed conjunctiva affords a conspicuous example of this appearance. In a subject that has suffered from an internal inflammatory attack, a good opportunity is frequently afforded of observing the enlarged and injected state of the vessels on which the red colour depends. But inflammation may have existed to a certain degree, and yet the parts may be pale, from the capillaries having emptied themselves into the veins immediately after the patient’s death. The paleness may be also in part caused by the influx of the red globules being impeded immediately after death, or when the patient is in articulo mortis, in consequence of the contraction of the vessels, which is well known to occur at that period.

It has been said that redness is not essential to inflammation; for serous vessels may be altered in size and function by this action, and yet not be sufficiently dilated to receive the red globules of the blood. And, again, that serous vessels may be enlarged so as to admit the red globules; and a part that is colourless when in the healthy state may, in consequence, assume a highly red hue when in an inflamed condition. This may be observed in the cornea lucida, which, when violently inflamed, is pervaded by numerous vessels, visible to the naked eye, distended with red blood, ramifying over the whole of it, and freely inosculating with each other. Some have even supposed that these vessels are newly formed, in consequence of inflammatory action. This opinion is, however, erroneous; as the vessels existed in the cornea previously, and are only increased in size, so as to admit of the accumulation of a sufficient number of red particles to render the vessels visible. The speedy, and, in many cases, instantaneous, appearance of red vessels where they could not previously be observed, decidedly overturns the opinion that new vessels are in such a case formed. New vessels are seldom formed, unless after a breach of structure, or in cases where morbid deposits become vascular. There is no proof of the existence of mere serous vessels in the human body, as any one may ascertain who is accustomed to examine the capillaries with a good microscope. Vessels which are so small as to admit only a very few, say one, or at most two rows of globules, would, of course, appear colourless, and these are what have been called serous vessels. The globules of blood are so small as to be invisible to the naked eye; and vessels carrying only one series of them would appear colourless. No vessels belonging to the sanguiferous system have ever been observed less in character than a blood globule; and this, so far as I have been able to observe, is, as nearly as possible, 1/3000 part of an inch. They appear to be flattened discs; and whether those of the human body have a central nucleus or not, seems, as yet, very doubtful. The globules are here shown upon a scale of 1/4000 part of an inch, linear, and in different positions. They are represented, as seen in the greater number of microscopes, having a central nucleus. Whether, in the blood of mammiferous animals, or not, this is an optical deception, is not very clearly made out; but in that of reptiles the nucleus is easily demonstrable. The redness then is not from error loci, or in consequence of red particles flowing where none flowed before, but from the capillaries becoming distended and dilated with an unusual quantity of blood, which is stagnated in the central part of the inflamed neighbourhood, the inflammatory focus.

Throbbing, to a greater or less degree, is always felt in an inflamed part by the patient; and it is frequently so distinct as to be readily perceived by an attentive examination. This arises, probably, from the stagnation of blood in the vessels of the part over-excited, and principally affected by the disease or injury, causing an increase in the collateral circulation; and it is this rapidly increased action around that gives rise to the signs and symptoms, and constitutes, in point of fact, what is known and recognised as inflammation. The sensation of throbbing is not, however, produced entirely by the action of the capillary vessels, but in consequence, also, of the larger trunks in the neighbourhood sympathising with these capillaries, and so having their action increased also. The obstruction of the capillaries in the early stage of inflammation must necessarily cause a greater force of the heart to be expended on the trunks leading to such capillaries; hence the greater impulse and velocity of blood in the circumferential and patent vessels. In fact, when the inflammatory action is extensive or severe, or when the part affected is of much importance to life, the whole circulating system is disturbed, and thus arises the sympathetic excitement of the constitution.

The incited action of those vessels in the more immediate vicinity of the inflamed part is well marked in cases of Paronychia. There the digital, the radial, and ulnar arteries, with their branches, beat more violently than usual; and with much greater force, though not more rapidly, than the vessels in other parts of the body.

Swelling is caused by the enlarged and overloaded vessels relieving themselves by effusion of part of their contents into the surrounding cellular texture. The effusion varies in extent and consistence, according to the degree of inflammatory action, and the species of resistance offered; at first it is serous, then mixed with fibrin, and consequently spontaneously coagulable. Cæteris paribus, the greater the resistance, the less the effusion, and the more violent the inflammatory action; the chance of its speedy and favourable termination is also more diminished. Even the enlargement of the blood-vessels produces a certain degree of intumescence previous to effusion. The relief to the vessels by effusion giving rise to swelling, when it occurs in loose cellular tissues, may be considered as a beneficent provision of nature. But in vital organs it may be productive of the most serious consequences; as in these, very slight effusion will often endanger the structure of the organ, destroy its functions, and not unfrequently be attended with fatal consequences.

The nature of the effused fluid varies according to the degree of violence and advancement of the action, and is also modified by the texture in which that action occurs. It may consist of serum, lymph, blood, or pus. In inflammation, in short, exhalation, though at first diminished, is soon much increased, whilst the powers of the absorbent vessels are diminished, or at least do not maintain their usual relation to those of the exhalants.

Pain is the next symptom enumerated. Here the very common error of supposing that where there is pain there must always be inflammation may be noticed. Some diseases attended with the most acute pain, as Tic Douloureux and Cramp, are generally unattended with inflammation. Many chronic diseases, too, are accompanied with violent and long-continued paroxysms of pain, without excited circulation of the part.

This erroneous opinion often gives rise to highly prejudicial proceedings, as—the exhausting, by copious depletions, the vital powers of patients, already enfeebled by continued disease or treatment—the consequent aggravation of the urgent symptoms—and, the then only termination of the disease and of the practice, death.

Again, it is true that we must bleed, in some cases, with the view of preventing the occurrence of inflammation; yet the prophylactic treatment may be carried too far, as in cases of violent injuries, or after severe operations. In these instances, the immediate abstraction of blood, so far from being beneficial, expedites the dissolution of the patient, or at least greatly retards the cure. Pains arising from local irritations are often treated in a similar way, whilst the removal of the cause would be much more likely to restore the natural action of the parts.

Though inflammation does not always accompany the sensation of pain, yet the latter, in a greater or less degree, attends inflammatory action; and, perhaps, it is fortunate that it does so. Because, were it not for the occurrence of pain, the patient’s attention would not be directed to the disease; he would continue to use the part as if in health, and the affection would thus be much aggravated. Whereas, according to the existing provision of nature, pain is felt at the commencement of the action, the presence of which the patient is thereby made aware of; and he is compelled to employ such measures for its removal as reason naturally dictates, of which none is more effectual than disusing the affected part. The nerves are thus the safeguards of the various parts of the body in health—their nurses in disease. A part deprived of sensation may be used, even to the destruction of its texture, without producing any impression on the sensorium, and consequently without the animal being conscious of it.

The presence of pain, as a symptom of inflammation, may be easily explained. The connexion of the vascular with the nervous system is very constant and intimate. Their ramifications accompany each other, and are contained in the same cellular sheath; and without the reciprocal influence of each, neither could perform its functions perfectly. By injecting a limb soon after its separation from an animal, and before its vital heat has departed, spasms of all muscles are sometimes produced; showing the intimate connexion between these two systems. This, however, is distinct from the contractions of the muscular fibre produced by the application of stimuli. In the former case, the contractions are universal, and induced through the medium of the nerves. In the latter, the irritability of the fibre is excited.

When the circulation is excited, the nerves accompanying the affected vessels are unusually compressed, and over-stimulated by the circulating fluid, in which, probably, some change takes place, and in this manner unnatural impressions are produced; the nerves themselves are likewise the seat of disease, in consequence of the enlargement of the minute capillaries which permeate them. Over-distension of the coats of the vessels may also be supposed to give rise to painful feelings, independently of any affection of the accompanying nervous trunks.

The degree of pain is generally in proportion to the sensibility of the part when in health; it also depends upon the distensibility of the parts affected, and on the intensity of the inflammatory action. When bones, tendons, &c., which in their uninflamed state are nearly insensible, become inflamed, the pain and suffering are most excruciating, owing to the resistance opposed to the dilatation of the vessels, and the prevention of the effusion by which they naturally relieve themselves.

The kind of pain also varies, in consequence of different modifications in the action causing different impressions on the sensorium. Pain is not always increased in proportion to the natural sensibility of the part; for in some instances the sensibility is rendered much more intense, while in others it is much obtunded.

The last, and, according to some writers, the only unequivocal symptom of inflammation, is Heat. In extravasation of blood into the cellular texture, as under the conjunctiva, there is redness, swelling, and occasionally pain; but at first, and unless the action of the bloodvessels be excited, there will be neither heat nor throbbing. In many internal inflammations heat is much complained of; and in Enteritis it has been considered a pathognomonic symptom.

The signs, symptoms, and consequences of inflammation—and amongst others, heat—are modified by the distance of the affected part from the centre of circulation. All actions, healthy as well as morbid, proceed with more vigour in the superior extremities—in the head, the neck, and the trunk, than in the more remote parts of the body; for to the former the blood is transmitted more speedily, if not in greater quantity, and is not so liable to be impeded in its return. Hence an arm may bear up under a severe injury, which, to an inferior extremity, would prove inevitable destruction. The heat, however, of an inflamed part, is generally supposed to be much greater than it really is. The sensation of heat is considerable to the patient, as well as to any observer, whilst the absolute increase of temperature is very slight indeed. It has been proved by the most decided experiments of Mr. Hunter, on the mucous canals of animals, first when in health, and again after violent inflammation had been excited, that little or no variation of temperature can be observed. The elevation of temperature is probably constant, though only amounting to a degree, or even less. As the blood is the source of heat, wherever an increased quantity is circulated, there should, to some extent, be increased heat.

The effects of an incited action of the vessels on the system at large must now be adverted to; or, in other words, that general disturbance in the system which attends inflammatory incitation, and which occurs in a degree proportioned to the power of the exciting cause, and the kind of texture primarily affected. The functions both of the sanguiferous and nervous systems are deranged, producing a state termed Symptomatic or Sympathetic Inflammatory Fever. From some observations of my friend Mr. Gulliver, it is probable that this state is frequently, if not generally, dependent on changes in the blood consequent on inflammation. A sort of decomposition of part of the fluid and vitiation of the remainder; the fibrin being separated and effused into the injured part for the purposes of reparation, while the blood globules are converted into pus in the capillaries, and mixed with the circulating fluid. Thus the presence of pus in the blood may become the proximate cause of fever; but if an outlet to the matter be established, if it be discharged by the occurrence of suppuration in a cavity or on a surface, the case is benefited and the constitution relieved. This points to an important principle in practice. Nature puts it in operation in small-pox, for example—how favourable it is for the pustules to come out, and to what danger is not the patient exposed if they are repelled.

During the paroxysm of inflammatory fever all the secretions and excretions are diminished or suppressed; and hence the hot dry state of the skin, the thirst with foul and dry tongue, the scanty and high coloured urine, and the constipation of the bowels. This last symptom, however, though it may arise partially from the diminished secretion of mucus, yet is often dependent on disturbance of the functions of the brain and nerves. The pulsations of the arteries become rapid and strong, the sanguiferous system being unable to relieve itself by effusion, in consequence of the obstruction of the exhalants.

If the extreme vessels are in any way obstructed, and the general circulation in consequence much accelerated, the internal viscera become oppressed, and are interrupted in their functions; and relief is experienced only when relaxation occurs in the vessels upon the surface of the body. Thus, in any violent and continued exertion, there is a sense of oppression in the chest, and the functions of the encephalon are somewhat disordered, but as soon as perspiration breaks out the relief is instantaneous, and the animal can, without difficulty, persevere in its exertions.

In inflammatory fever, the breathing is often difficult, and the appetite declines; the patient is restless and watchful, and when he does sleep, he is not thereby refreshed. In the more violent cases, the sensorial functions are much disturbed; even delirium supervenes, with violent muscular exertion and convulsions, and may be followed by coma, should the local affection not subside. The delirium attendant on violent diseases and accidents may often be considered a beneficent effect of nature’s operations; for the patient, frequently losing all consciousness of his situation, seems to be under the influence of the most pleasing hallucinations, and is freed from the more lamentable state of severe mental as well as bodily affliction.

Writers on Inflammation have expatiated at great length on Sympathies; and these have been divided into, 1st, The Partial—the Remote, the Continuous, and the Contiguous;—Remote, when parts sympathise, though situated at a considerable distance from each other;—Contiguous, when the sympathetic action seems to be produced, in separate parts, merely from juxtaposition;—Continuous, when the action extends in parts which are of similar texture, and conjoined with that which is primarily affected.—2d, Universal, where the whole system suffers along with parts of it. For instance, the whole system is often disturbed by a deranged state of the alimentary canal, and, conversely, the bowels, or the skin, the brain, the osseous or any other of the textures, may suffer from a general disorder.