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,[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.
[Illustration]
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.