Part 4

The system sympathises much more with some parts than with others; and we accordingly find that disorder in one part will give rise to alarming constitutional excitement, whilst in another, a much greater derangement in function and structure will apparently be almost entirely disregarded by the constitution.

Irritation is an effect of sympathy, and differs from inflammation, inasmuch as the functions of the nervous system, and not those of the sanguiferous, are disturbed;—the latter frequently supervenes on the former. Irritation is local, or constitutional. As examples of the strictly local species, may be mentioned that peculiar and dreadfully annoying sensation produced in the alveoli by the presence of a diseased tooth, or the irritation caused by ascarides in the rectum, or by stone in the bladder.

But, from this action being dependent on the nervous agency, irritation is frequently produced in a part remote from the source of the action. Thus, if an irritating cause of any kind be applied to the origin of a nerve, the effects of the irritation may be evinced in a part supplied by its extreme branches; while, if the cause is applied to the termination of a nerve, a similar action is produced at its commencement, and in parts supplied by nerves from the same origin. Thus, disease of the hip-joint causes pain in the knee, whilst dentition in children not unfrequently produces fatal effusion at the base of the brain; and again, irritation at the neck of the bladder frequently gives rise to pain in the feet.

Local impressions, injuries, or irritations, though apparently of little importance, frequently produce irritation which affects the whole system, and is therefore termed constitutional. Syncope sometimes follows the passing of a bougie along the urethra. We meet with too many instances of constitutional irritation following severe injuries or operations, especially if attended with much hemorrhage. In general, there is considerable prostration of strength; the patient is anxious and restless; his sleep is disturbed; the pulse is weak and fluttering, occasionally intermittent; the tongue is white and loaded; the appetite is gone; the stomach rejects the little food which the patient is able to take; he is startled and annoyed by the slightest external impression. At this period of the disorder, rigors generally occur, and are followed by a sense of heat, and by perspiration; then the above symptoms gradually decrease, and the patient recovers; but in certain instances his breathing becomes quick and somewhat oppressed, attended with a peculiar spasmodic elevation of the nostrils; all the secretions are diminished, the intellectual functions become impaired, and there are occasional convulsive twitchings; coma supervenes, preceded by a low muttering delirium, and followed by death.

This action, as well as every other, is much modified by the importance of the part which is the source of the action, and by the constitution of the patient. It is more severe in children than in adults. The affection will be more fully detailed, when treating of local injuries, and the management of patients after severe operations.

The Causes of Inflammation come next to be considered; and first, of the proximate cause or theory. The different states of the Vessels, in their healthy and in their incited condition, have given rise to much discussion. In the first place, considerable difference of opinion exists as to the relative share which the heart, the larger arteries, and the capillaries, have in propelling the circulating fluid in a state of health. Some physiologists are inclined to attribute the principal power to the heart, the blood being propelled and returned, according to them, almost entirely by the vis a tergo; while they suppose that the arteries possess merely a degree of elasticity or tonicity. Considering the arteries as elastic tubes, performing an indispensable part in the propulsion of the blood, we will now briefly consider their state in inflammation.

Passing over the different theories of error loci, spasm, &c., which have at various times been entertained, let us first examine the condition of the capillary vessels, for these are primarily and principally concerned. In inflammation, the balance of the circulation is destroyed, but a diversity of opinion has existed as to the precise nature of the change which occurs. It has been supposed, and perhaps correctly, that the circulation is, in the first instance, much accelerated in the capillary vessels of an inflamed part; but it has been satisfactorily proved by experiment, that, after inflammation is fairly established, the blood circulates more slowly than in the healthy state of the vessels. There appears, in fact, to be, as insisted upon by some writers on the subject, a state of excitement, then of collapse, followed, if the life of the part is not destroyed, by reaction. When a part is stimulated, the circulation is accelerated, and a greater quantity of blood is transmitted by its vessels: if the excitement is speedily removed, they recover themselves, though perhaps a little dilated, and no inflammation ensues. If, for instance, a foreign body of any kind gets entangled betwixt the upper eyelid and the bulb of the eye, and it is permitted to remain a few moments only, redness of the whole surface of the conjunctiva takes place, but it is transitory, and disappears entirely some short time after the extraction of the foreign body. If, however, it is permitted to continue longer in contact with this sensible surface, the membrane reddens more and more, and becomes thickened. Violent pain, with discharge of tears, and alteration of the secretion from the mucous surface, take place, ophthalmia is, in fact, established. If the exciting cause is applied for a sufficient length of time, the extreme vessels lose their contractility, they are weakened, become dilated, and the contained blood circulates slowly. When inflammation is fairly established in a part, the capillaries become considerably dilated, and the blood is often completely stagnated in the inflammatory point. In the circumference of this focus, it is accelerated as formerly noticed: the blood is probably stagnated for two or three days in the capillaries and in the contiguous cellular tissue, when the action is at all violent. It, however, begins to move again; it loses its colouring matter, while stagnated; the fibrin is assimilated to the neighbouring parts, or rather effused, so as to cause the thickening, and the blood globules have possibly undergone a change, and been converted into those of pus. If the disease be of a limited extent, and without breach of surface, they are carried into the circulation very gradually, and in such small numbers as not to produce injury to the health; otherwise the contamination of the blood by a large quantity of pus causes inflammatory fever. It is probable that the permanent dilatation occurs in consequence of the larger vessels in the immediate vicinity being incited, and propelling more blood into the minute capillaries than they can readily return into the corresponding veins; and in consequence of so great a degree of distension being produced, the vessels are incapable of again speedily contracting; the blood, also, from being stagnant, becomes of a darker colour. The larger trunks propelling blood into the distended and comparatively inert capillaries, which are incapable of transmitting into the veins the same quantity of fluid which they receive, will cause the throbbing or pulsating sensation. The blood circulating in the parts around is sometimes apparently changed in quality; it is redder, flocculi appear floating in it, and the globules disappear. These last may have been broken down, or partial decomposition may have taken place from a loss of vital power in the vessels themselves.

The blood globules are, perhaps, merely compressed; for whenever motion is produced in the fluid, they speedily reappear. Fresh globules also find their way into the affected capillaries from neighbouring vessels. The alteration in the component parts of the blood has been supposed to depend upon the previous state of the inflamed vessels in which it is contained: it is said soon to reassume its natural appearance, when brought into a healthy vessel, and reference is made to experiments on the web of the frog’s foot. When once altered, it is, however, questionable if the blood ever reassumes its natural appearance; of course the blood which takes the place of that which was stagnated in the capillaries will be natural. If there have been extensive inflammation, and therefore much altered blood, one of two things will happen, viz., inflammatory fever and its consequences, or the discharge of the offending matter (the altered blood) as pus. We may also conclude that the blood of an inflamed part undergoes chemical changes; for when the part becomes gangrenous, the blood then loses its red colour, and assumes a yellowish-brown hue, from the absorption of its colouring matter, which necessarily implies an alteration in its chemical constitution. It seems not unlikely, that the change which is early observed in the appearance of the blood of an inflamed part is the commencement of a chemical process, which, if the vessels do not regain their contractile power, terminates in the total destruction of the ordinary properties of that fluid. It is probable that the more modern speculators in medical science have paid too little attention to the state of the fluids, and to the fact that, when diseased action occurs in a part, its secretions and supplying fluid are very considerably changed.

But the blood in inflammation also undergoes a change, observable after its removal from the circulation, and especially when the system sympathises with the part affected. The blood, it is generally believed and stated, does not coagulate so quickly as in the natural state, or else, it is said, the red globules, being increased in specific gravity, fall rapidly to the lower part of the containing vessel, so that a yellowish crust appears on the surface of the crassamentum or clot; and this appearance is termed the inflammatory or buffy coat. The blood extracted from the veins of a patient labouring under inflammatory fever often appears to coagulate very quickly; but it contains an unusual proportion of fibrin. In certain states of inflammation, this crust is also much contracted, so that its marginal circumference is at a considerable distance from the sides of the containing vessel; its margins also are elevated and inverted; its upper surface is smooth, whilst the under adheres firmly to the coagulum; and in this state the blood is said to be cupped, as well as buffed. The appearance of the buffy coat is not peculiar to the inflammatory state, but is apparently dependent on hurried circulation, however occasioned. It frequently presents itself in blood removed from the circulation during pregnancy, and in several other conditions of the system, apparently altogether unconnected with inflammatory excitement. In these circumstances, however, the contracted or cupped appearance of the coagulum is hardly ever observed. An ignorance of the above fact leads to dangerous practice, inasmuch as certain practitioners will bleed, and continue to bleed, for very equivocal inflammatory symptoms, conceiving themselves fully warranted in so doing by the presence of the buffy coat. This coat is often not so apparent in the blood first drawn as in that afterwards abstracted.

In inflammation, as was formerly remarked, a greater quantity of blood not only flows into the capillary vessels, but it also escapes from them, or is extravasated. This may occur with or without rupture of the vessels, and to a greater or less extent, according to the violence of the action, and the texture of the part.

When local inflammatory action exists to a considerable degree, the general circulation is more or less disturbed. The heart, and the larger vessels supplying the capillaries, which are more immediately concerned in the local action, subsequently sympathise with the part affected, and, acting with greater vigour than usual, propel the blood into the extreme branches; so that the inflammatory excitement may be said to be gradually communicated by the continuous sympathy, till the whole sanguiferous system becomes subject to its influence. The degree of this general excitement depends greatly on the texture and function of the part primarily affected.

The term Passive Inflammation has been applied to that state in which the larger vessels are not excited, or have ceased to sympathise with the capillary branches. The term Chronic Inflammation is properly limited to the consequence of the acute inflammatory action, the part remaining turgid and swollen, the vessels over-distended with dark blood, but with little or no pain, and without heat or throbbing. Congestion is also employed to denote fulness of the vessels, large as well as small, when no sign of excited circulation, or of decided inflammatory action, has occurred. It is most frequently used, however, when describing the condition of an internal organ. An over-distention of a particular set of vessels may certainly exist (as a consequence of inflammation, or altogether unconnected with it), unattended with inflammatory action. These two states ought to be carefully distinguished from a similar condition of the vessels, attended with inflammation; for practice, which would be beneficial in the one case, is highly prejudicial in the other, and lamentable examples of the non-attention to this distinction are every day observed.

It may here be mentioned, that some have denied the existence of vitality in the blood; and to some minds it may, perhaps, be difficult to conceive how a fluid should be possessed of this principle. But no one can either doubt or deny that the blood, in its distribution, in its manner of receiving increase, in the secretions furnished by it, and in its various morbid changes, is governed by certain laws and principles which cannot be explained by those of chemistry or mechanics, but must belong to some other power. It is allowed, and has been promulgated by all authors, that the blood is one of the most active agents in the animal economy—in repairing waste, in affording peculiar fluids necessary in that economy, in supplying organs with materials for carrying on their functions, &c.; and yet all this, according to some, is accomplished by a dead animal fluid; no one can plausibly object to the laws by which the blood is governed being referred to the power of life, and to their being called Vital Principles.

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, cupping, punctures, or incisions. 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.

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.