Part 4

Certain circumstances give rise to inflammation, and have been called its _Exciting_ or _Immediate Causes_. Among the external applications producing inflammation, stimulants bear a conspicuous part; the effects of which, in causing this action, are well shown by many experiments that have been performed on the lower animals: by the application of ammonia, spirits of wine, or common salt, for example, to the diaphanous web of a frog’s foot. As stimulants usually causing inflammatory action, by their being applied to the surface of the body, may be enumerated acids, alkalies, certain salts, animal substances, such as cantharides, the juices of many plants, many poisons, an excessive degree of heat, &c. Any solid substance, though by no means acrimonious in its quality, may act as an exciting cause, as by pressure or friction.

Wounds also, especially when of considerable size, and occurring whilst the constitution is in an unhealthy condition, give rise to local, and occasionally general, inflammatory action.

This action is besides frequently produced by injury from an obtuse body causing a bruise or fracture; by the lodgement of extraneous substances, or of decayed portions of the system,—such as portions of bones, tendons, &c.; or by irritating matter generated in the system itself,—by concretions, tumours, vitiated secretions, &c.

One of the most frequent causes of inflammation is cold; the action of which, however, cannot always be readily explained. In some instances, it appears to act directly on a part, as in inflammation of the mucous membrane lining the organs of respiration: in others, its action is indirect, probably by disturbing the equality of the circulation, the inflammation occurs in a part distant from the surface the temperature of which had been diminished. In the great majority of instances in which inflammation has occurred, in consequence of very intense cold, it is produced by the sudden application of heat whilst the temperature of the part is greatly below the natural standard, as will afterwards be more particularly illustrated. But the inflammatory action may be produced, even though no heat be afterwards applied directly to the part, by its vessels being too rapidly brought into a degree of action similar to that of the surrounding parts which are in their natural condition. Sudden and general diminution of temperature seems to act as an exciting cause, by producing an instantaneous suppression of the transpiration. Another exciting cause of the inflammation, is the retention of the secreted fluids, causing unnatural distension of canals or cavities, and is exemplified by cystitis occurring in consequence of retention of urine. Certain states of the constitution are justly supposed to excite inflammation, in particular textures. Other exciting causes of inflammation might be enumerated, but these will be more naturally explained, and more fully considered, whilst treating of inflammation of the various tissues and organs. Their effects are various and diversified, according to the intensity of the cause, the structure, function, and sympathies of the part affected, and the state of the system. And it is also to be remembered, that not unfrequently inflammatory action appears, whilst we can assign no cause for its production.

Inflammation is said to terminate in _Resolution_, _Suppuration_, and _Mortification_. The application of the word termination, however, is injudicious; for in general the inflammatory action, though much abated, is not extinguished by the occurrence of suppuration or mortification, but often continues in the surrounding parts with unabated intensity; and not unfrequently several of the terminations occur combined with each other.

_Adhesion_ has also been mentioned as a termination of inflammation, but perhaps improperly; for, although in certain parts of the body, as in the serous cavities, adhesion is produced in consequence of inflammatory action, and during its progress, still the process of adhesion is altogether independent of this action in other textures, such as the cellular. In the uniting of a flesh wound, a certain degree of incited action of the blood vessels is necessary for the accomplishment of the adhesive process; but should that incited action reach the inflammatory pitch, the union by the first intention is interrupted, and the wound must heal by granulation with suppuration. The process of adhesion will be more properly attended to when treating of wounds.

The various terminations of inflammation are salutary or destructive, according to circumstances; but resolution is, in general, the one most to be desired; complete resolution, however, perhaps seldom occurs; after the inflammatory action has attained a certain point, this cannot be expected to happen.

Resolution takes place in consequence of the reëstablishment of the circulation in the capillaries, in which the blood had stagnated; hence the diminution of the increased action in the larger vessels—the effused fibrin, at the same time, if there was much swelling, is partly absorbed. The circulation in the part becomes again natural, and the circulating fluid also resuming its healthy properties, the redness and sensation of throbbing cease. In consequence of the bloodvessels regaining their contractility, the nervous system is no longer preternaturally stimulated, and thus the increased sensibility is done away with. In short, when inflammation terminates in resolution, the part is left in the same state in which it was previous to the supervention of the attack. It is not an instantaneous process, but gradual in its completion.

Again, it not unfrequently happens, when inflammation has occurred in the surface, and continued for a short period, that it spontaneously disappears, and does not again return; the action is said to terminate in _Delitescence_, and of course this is always a favourable occurrence. But if the inflammation, after having suddenly disappeared, attacks another part at a distance from that first affected, the change is termed _Metastasis_. If the inflammation leaves an internal viscus, and appears on the surface of the body, the circumstance is favourable; but if it leaves the latter to attack the former, the result is highly dangerous.

_Treatment._—In the treatment of inflammation, with a view of procuring resolution, our attention must be first directed to the exciting cause: it is, if possible, to be discovered, and removed. Thus, foreign bodies are to be extracted—fractures reduced—strictures divided—unnatural accumulations of fluid withdrawn, &c. In many cases, if the exciting cause is removed, nothing more is required; the inflammation speedily subsides. If the cause cannot be removed, or if, after its removal, the inflammation proceeds unabated, the arterial action must be reduced by general and local abstraction of blood. By general depletion, the action of the whole sanguiferous system is diminished, as well as of those vessels more immediately engaged in the morbid action; but the affected capillaries are still dilated, and less capable than the larger trunks of effective contraction to propel their contents; and are therefore only sufficiently depleted by the local abstraction of blood, by leeches,[3] cupping, punctures, or incisions.[4] Blood may be drawn either from arteries or from veins. In Arteriotomy, the blood is discharged more rapidly, and its flow is of longer continuance, than from a vein, so that the system may thereby be almost completely deprived of its circulating fluid; and perhaps a more speedy impression may be made on the inflammatory action. One objection to venesection is, that after frequent and copious venous hemorrhage, the internal vessels become gorged with blood, and a disposition to apoplexy is induced.

But bleeding is not to be had recourse to without due consideration of the age, strength, constitution, and idiosyncrasy of the patient; if employed, it must be modified according to these; and it has already been mentioned, that depletion is not always to be persevered in on account of the presence of the buffy coat.[5]

Bleeding is materially assisted in reducing the activity of the circulation, by the employment of saline purgatives, along with nauseating doses of antimony. Diaphoretics are of essential service in promoting the action of the exhalants, and thereby relieving the affected capillaries. The exhibition of opium is frequently advantageous, more especially after depletion, in allaying the painful sensations when severe, and averting reaction, and also in procuring refreshing sleep, when the patient is anxious and restless. Digitalis has been administered, with the view of reducing the arterial action; but it has been fully established, that this medicine acts at first as a direct stimulant, and that it is only after its use has been continued for some time that its effects become sedative.

The local applications to an inflamed part are sometimes made hot, sometimes cold. The latter will perhaps be at first the more grateful to the sensations of the patient. They are, however, with greater propriety employed before inflammatory action is fairly established, and they act by constringing the superficial vessels with which those more deeply seated sympathise to a certain extent; but warm fomentations are more pleasant and useful when inflammation has really taken place; they relieve the pain more effectually, and at the same time promote the cutaneous transpiration; they relax the surface moreover, effusion is thus encouraged, the deeper vessels are so far relieved of their load, and the pressure upon, and stimulation of, the nerves are thus diminished. After the violence of the symptoms has abated somewhat, the vessels still, however, being loaded with blood, the inflammation in fact having become chronic, stimulants may with propriety be applied directly to the affected parts; these are employed, perhaps, with greatest advantage immediately after the bloodvessels are unloaded by leeching, scarification, or punctures; this practice is borne out by the result of experiment and observation. It is seen, that after the vessels have become dilated, and the blood has stagnated in them through the infliction of injury, or the application of some stimulating substance, that the employment of another and different stimulus immediately causes the contraction of the capillaries, and the renewal of active circulation.

During an inflammatory attack, the patient should be allowed very little food, and what he does receive must contain little nutriment in proportion to its bulk. But in many cases it is unnecessary to enjoin such abstinence, as the patient has no appetite, and refuses food.

In inflammation of deeply-seated parts, such as the apparatus of some articulations, it is a frequent mode of assisting the completion of resolution to excite inflammatory action in an external, and consequently less vital and important part. This is accomplished by the application of stimuli, caustics, cautery, setons, &c.

It appears that the stimulating substance produces an incited action of the bloodvessels, or a revulsion, according to the older authors, in the part to which it is applied; and that, consequently, the neighbouring arterial trunks, in order to sustain that incited action, supply the part with a larger proportion of their contents than it usually receives; and the necessary consequence of the stimulated part receiving an additional supply of blood is, that the part originally inflamed receives less. The effect, indeed, seems analogous to that of topical bleeding, with this difference—that it is more permanent. Besides, it determines suppuration on the surface, and so renders it less necessary for the vessels to produce pus in a worse situation—the deeper seated parts.

But it must be borne in mind, that this method is not to be resorted to in the commencement, or during the active state, of the inflammatory action, but only when that action has begun to decline, otherwise the disease may be much aggravated, instead of being relieved.

If, notwithstanding all the means employed to procure resolution, the inflammatory action continues unabated, the result next to be desired and accelerated is Suppuration; and with this view, it becomes necessary to change the treatment, both local and general.

Above all, disuse and a proper position of the affected part must not be neglected. Unless absolute repose is strictly enjoined and attended to, and the return of blood from the inflamed tissues is favoured, very great difficulty will, in the majority of cases, be experienced in removing any of the signs or symptoms of inflammatory action, even by the most energetic means, general or local. This will be more fully insisted upon in the progress of the work.

OF SUPPURATION AS A CONSEQUENCE OF INFLAMMATORY ACTION.

It has already been stated, that the blood is stagnated in the capillaries occupying the centre of the inflamed part, as well as extravasated in the contiguous cellular tissue. Pus has long been considered as a secretion; but, from the time of Mr. Hunter downwards, a great similarity between the globules of pus and those of blood has been recognised: the former, however, are spherical, larger, and rougher on the surface, and are not so regular in size as those of blood; their diameter is between 1/2000 and 1/3000 of an inch, although some of the globules may be occasionally seen a little larger or smaller than these measurements. Smaller particles are also detected, the molecules of the pus globules, each of which contains two or three. These molecules are insoluble in acids, soluble in caustic alkalis, and can be freed from the fibrous capsule in which they are contained, and of which the pus globule is composed, when treated with acetic acid. The appearance of the pus globules and molecules is here shown upon a scale, the squares of which are 1/4000 of an inch. These small particles were pointed out to me by my friend, Mr. Gulliver, nearly two years ago, as constituting an important element in suppuration. It results from his observations that the entire pus globule is composed in its central part of these minute molecules, the diameter of which is from 1/10666 to 1/8000 of an inch, cemented together, as it were, by a superficial deposit of matter possessing all the properties of coagulated lymph. And these minute nuclei constitute a proximate animal principle, possessing such well marked characters as to justify us in regarding them as peculiar in their nature, and essential to the composition of the pus globule. Thus they resist putrefaction with remarkable pertinacity, are very dense, and spherical in form, and are insoluble in some acids which act with facility on albumen, fibrin, or the blood-corpuscle. They are easily seen by treating a little recent pus with sulphurous acid, which so acts on the pus-globule as to render the nuclei distinctly visible through its fibrinous capsule; by sulphuric acid the external part of the pus-globule is quickly dissolved, and the nuclei, somewhat shrunk, are seen in considerable numbers floating separately about the field of vision. The instrument used by Mr. Gulliver in these observations was a compound achromatic microscope, with a deep object glass, having one-eighth of an inch focal length.

In many constitutions, the slightest incited action of the vessels is followed by the formation of pus, and the appearance of a depôt of purulent matter is often the first indication that such action has existed; but in the majority of instances, the deposition of pus is preceded by the usual characters of well-marked inflammatory action. Suppuration occasionally occurs without previous solution of continuity; for pus is frequently contained in the serous and mucous cavities, when no breach of continuity can be discovered, at least we find a fluid not distinguishable from purulent matter; it may be a vitiated secretion, but still it presents the usual characters of pus. But it occurs, generally, when there has been a previous læsion of structure, and in this case its progress is most distinctly marked. In exposed cellular texture, for example, particles of blood are effused; the serum is afterwards absorbed, and the lymph remains; this latter gives transmission to minute vessels which deposit the purulent fluid, whilst others secrete particles of organised matter to form granulations, in order to repair the loss of substance. This process is often unattended with any great degree of constitutional disturbance, because the fibrin effused sets a bound to the pus, and is the provision against its being mixed in large quantities with the blood. In healthy suppuration, the separation of fibrin and pus from the blood in this way seems to have direct relation to each other; and in unhealthy inflammation, when this does not take place, the consequences are mixture of pus with the blood as formerly noticed. In the latter form of suppuration the fibrin, instead of being assimilated to the contiguous mass, is mixed with the pus; hence the proneness to putrefaction of such discharge, and its disposition to coagulate spontaneously when evacuated. This kind of suppuration, being matured generally without thickening of parts, has been sometimes pointed out as suppuration independently of previous inflammatory action.

After purulent matter has begun to accumulate under the surface, the pressure thereby occasioned produces condensation of the neighbouring cellular tissue, which, along with the previously effused lymph, forms the parietes of the abscess; and in proportion as the matter accumulates, the cavity enlarges by the successive processes of ulceration of portions of its parietes, by continued effusion of lymph, and by farther condensation of the surrounding parts. Thinning of the parietes takes place by ulcerative absorption, particularly towards the surface—or, if that be difficult, towards a mucous outlet—as is exemplified by the bursting into the bowels or bronchiæ of abscess of the liver.

But in some instances, when no lymph is previously effused, and no cyst is formed, the matter is not confined, but pervades the cellular substance extensively, and is generally followed by more or less sloughing of that tissue, and by great constitutional disturbance. This most frequently occurs in patients of a debilitated habit, in whom the incited action has been so slight as not to cause the effusion of lymph, by which nature usually sets bounds to the suppurating process.

M. Gendrin advanced the opinion that pus was nothing but transformed blood; but his experiments on frogs are at least doubtful, since Mr. Gulliver, on repeating them, could not by any means induce the process of suppuration in these animals. It has been rendered probable by this gentleman’s observations that suppuration is a sort of proximate analysis of the blood, the fibrin being added to the contiguous parts, as in causing them to swell, forming the cysts of abscesses; the blood globules altered into pus being discharged as useless and excrementitious matter.

Pure pus is heavier than water, of a yellowish-white colour, somewhat of the consistence of cream. It is very little inclined to putrefaction, less so, perhaps, than any animal fluid not oily. It is composed of globules, and a clear transparent fluid, coagulable, it has been said, by the muriate of ammonia. When a solution of this salt produces any change, it is by rendering the pus more ropy; not coagulation, but a sort of gelatinisation follows. It is said also to be sweet and “mawkish to the taste.”

In unhealthy pus, such as already noticed, or in vitiated muco-puriform secretion, the colour and consistence are different, and flakes, resembling portions of lymph, are seen floating in it: they consist of fibrin thrown off with the pus, instead of being used for reparation and bounding the extent of the abscess; and by this latter circumstance such fluid is distinguished from the pure or laudable pus. In purulent matter also, especially that of an unhealthy character, the existence of a quantity of sulphureted hydrogen is indicated by the blackening of silver probes, and of various substances applied to the sore. It is necessary to bear in mind, that a matter resembling pus in many particulars, but in reality differing essentially from it, has generally been regarded as true purulent fluid; for it results, from some observations of Mr. Gulliver, that the pulpy matter, so frequently found in the substance of fibrinous clots of the heart and veins, is simply fibrin which has coagulated and passed into the state of softening, which he regards as a very frequent elementary disease. The subject is one of great interest, because it is connected with the theory of suppuration, and tends to modify materially our views on the pathology of the veins.

The symptoms attendant on suppuration vary much according to the nature of the parts involved. In general, it is accompanied with the subsidence of acute pain and fever; but, in unyielding textures, the increase of swelling, by the formation of purulent matter, is often attended with an aggravation of the symptoms, and with an increase of danger to the structures affected. The pain which accompanies suppuration is dull, and attended with a sensation of fulness and throbbing, and an increase of the tumour; ultimately the parietes of the abscess become absorbed, and the collection, being more superficial, the most careless observer must be convinced of its existence, by the less equivocal signs of fluctuation and pointing. In general, especially when the abscess is deeply seated, a greater or less degree of œdema surrounds it, producing a soft pitting tumour; but not unfrequently, when the degree of excitement is more intense, lymph, instead of serum, is effused, rendering the part more hard and resisting: in such cases it may be difficult to discover the existence of purulent matter, and the tactus eruditus, as it is called, will be found of material service; for, though pus is neither acrid nor corroding, still, if allowed to remain for any long period, much mischief may be caused—the bones may become diseased—muscles and tendons may slough—and the matter may discharge itself, by means of ulceration, into certain cavities and canals, and produce very serious consequences. Of the bad effects produced by the pressure and irritation of extensive and undisturbed collections of purulent matter, every practitioner must have seen numerous examples. Still, through prejudice, erroneously conceived opinions, or servile imitation, the greatest dread seems, with many, to exist of the practice of giving a free exit to the contents of such depôts.

The symptoms and sensible signs of suppuration are usually preceded by shivering, recurring at intervals, and commonly terminating in profuse perspiration. But this is by no means an unequivocal sign of the occurrence of suppuration; and this process very often takes place without any feeling of rigor.