INFLAMMATION
Definition--Nature of inflammation from surgical point of
view--Sequence of changes in bacterial inflammation--Clinical
aspects of inflammation--General principles of treatment--Chronic
inflammation.
Inflammation may be defined as the series of vital changes that occurs
in the tissues in response to irritation. These changes represent the
reaction of the tissue elements to the irritant, and constitute the
attempt made by nature to arrest or to limit its injurious effects, and
to repair the damage done by it.
The phenomena which characterise the inflammatory reaction can be
induced by any form of irritation--such, for example, as mechanical
injury, the application of heat or of chemical substances, or the action
of pathogenic bacteria and their toxins--and they are essentially
similar in kind whatever the irritant may be. The extent to which the
process may go, however, and its effects on the part implicated and on
the system as a whole, vary with different irritants and with the
intensity and duration of their action. A mechanical, a thermal, or a
chemical irritant, acting alone, induces a degree of reaction directly
proportionate to its physical properties, and so long as it does not
completely destroy the vitality of the part involved, the changes in the
tissues are chiefly directed towards repairing the damage done to the
part, and the inflammatory reaction is not only compatible with the
occurrence of ideal repair, but may be looked upon as an integral step
in the reparative process.
The irritation caused by infection with bacteria, on the other hand, is
cumulative, as the organisms not only multiply in the tissues, but in
addition produce chemical poisons (toxins) which aggravate the
irritative effects. The resulting reaction is correspondingly
progressive, and has as its primary object the expulsion of the irritant
and the limitation of its action. If the natural protective effort is
successful, the resulting tissue changes subserve the process of repair,
but if the bacteria gain the upper hand in the struggle, the
inflammatory reaction becomes more intense, certain of the tissue
elements succumb, and the process for the time being is a destructive
one. During the stage of bacterial inflammation, reparative processes
are in abeyance, and it is only after the inflammation has been allayed,
either by natural means or by the aid of the surgeon, that repair takes
place.
In applying the antiseptic principle to the treatment of wounds, our
main object is to exclude or to eliminate the bacterial factor, and so
to prevent the inflammatory reaction going beyond the stage in which it
is protective, and just in proportion as we succeed in attaining this
object, do we favour the occurrence of ideal repair.
#Sequence of Changes in Bacterial Inflammation.#--As the form of
inflammation with which we are most concerned is that due to the action
of bacteria, in describing the process by which the protective influence
of the inflammatory reaction is brought into play, we shall assume the
presence of a bacterial irritant.
The introduction of a colony of micro-organisms is quickly followed by
an accumulation of wandering cells, and proliferation of
connective-tissue cells in the tissues at the site of infection. The
various cells are attracted to the bacteria by a peculiar chemical or
biological power known as _chemotaxis_, which seems to result from
variations in the surface tension of different varieties of cells,
probably caused by some substance produced by the micro-organisms.
Changes in the blood vessels then ensue, the arteries becoming dilated
and the rate of the current in them being for a time increased--_active
hyperæmia_. Soon, however, the rate of the blood flow becomes slower
than normal, and in course of time the current may cease (_stasis_), and
the blood in the vessels may even coagulate (_thrombosis_). Coincidently
with these changes in the vessels, the leucocytes in the blood of the
inflamed part rapidly increase in number, and they become viscous and
adhere to the vessel wall, where they may accumulate in large numbers.
In course of time the leucocytes pass through the vessel
wall--_emigration of leucocytes_--and move towards the seat of
infection, giving rise to a marked degree of _local leucocytosis_.
Through the openings by which the leucocytes have escaped from the
vessels, red corpuscles may be passively extruded--_diapedesis of red
corpuscles_. These processes are accompanied by changes in the
endothelium of the vessel walls, which result in an increased formation
of lymph, which transudes into the meshes of the connective tissue
giving rise to an _inflammatory œdema_, or, if the inflammation is on a
free surface, forming an _inflammatory exudate_. The quantity and
characters of this exudate vary in different parts of the body, and
according to the nature, virulence, and location of the organisms
causing the inflammation. Thus it may be _serous_, as in some forms of
synovitis; _sero-fibrinous_, as in certain varieties of peritonitis, the
fibrin tending to limit the spread of the inflammation by forming
adhesions; _croupous_, when it coagulates on a free surface and forms a
false membrane, as in diphtheria; _hæmorrhagic_ when mixed with blood;
or _purulent_, when suppuration has occurred. The protective effects of
the inflammatory reaction depend for the most part upon the transudation
of lymph and the emigration of leucocytes. The lymph contains the
opsonins which act on the bacteria and render them less able to resist
the attack of the phagocytes, as well as the various protective
antibodies which neutralise the toxins. The polymorph leucocytes are the
principal agents in the process of phagocytosis (p. 22), and together
with the other forms of phagocytes they ingest and destroy the bacteria.
If the attempt to repel the invading organisms is successful, the
irritant effects are overcome, the inflammation is arrested, and
_resolution_ is said to take place.
Certain of the vascular and cellular changes are now utilised to restore
the condition to the normal, and _repair_ ensues after the manner
already described. In certain situations, notably in tendon sheaths, in
the cavities of joints, and in the interior of serous cavities, for
example the pleura and peritoneum, the restoration to the normal is not
perfect, adhesions forming between the opposing surfaces.
If, however, the reaction induced by the infection is insufficient to
check the growth and spread of the organisms, or to inhibit their toxin
production, local necrosis of tissue may take place, either in the form
of suppuration or of gangrene, or the toxins absorbed into the
circulation may produce blood-poisoning, which may even prove fatal.
#Clinical Aspects of Inflammation.#--It must clearly be understood that
inflammation is not to be looked upon as a disease in itself, but rather
as an evidence of some infective process going on in the tissues in
which it occurs, and of an effort on the part of these tissues to
overcome the invading organisms and their products. The chief danger to
the patient lies, not in the reactive changes that constitute the
inflammatory process, but in the fact that he is liable to be poisoned
by the toxins of the bacteria at work in the inflamed area.
Since the days of Celsus (first century A.D.), heat, redness, swelling,
and pain have been recognised as cardinal signs of inflammation, and to
these may be added, interference with function in the inflamed part, and
general constitutional disturbance. Variations in these signs and
symptoms depend upon the acuteness of the condition, the nature of the
causative organism and of the tissue attacked, the situation of the part
in relation to the surface, and other factors.
The _heat_ of the inflamed part is to be attributed to the increased
quantity of blood present in it, and the more superficial the affected
area the more readily is the local increase of temperature detected by
the hand. This clinical point is best tested by placing the palm of the
hand and fingers for a few seconds alternately over an uninflamed and an
inflamed area, otherwise under similar conditions as to coverings and
exposure. In this way even slight differences may be recognised.
_Redness_, similarly, is due to the increased afflux of blood to the
inflamed part. The shade of colour varies with the stage of the
inflammation, being lighter and brighter in the early, hyperæmic stages,
and darker and duskier when the blood flow is slowed or when stasis has
occurred and the oxygenation of the blood is defective. In the
thrombotic stage the part may assume a purplish hue.
The _swelling_ is partly due to the increased amount of blood in the
affected part and to the accumulation of leucocytes and proliferated
tissue cells, but chiefly to the exudate in the connective
tissue--_inflammatory œdema_. The more open the structure of the tissue
of the part, the greater is the amount of swelling--witness the marked
degree of œdema that occurs in such parts as the scrotum or the eyelids.
_Pain_ is a symptom seldom absent in inflammation. _Tenderness_--that
is, pain elicited on pressure--is one of the most valuable diagnostic
signs we possess, and is often present before pain is experienced by the
patient. That the area of tenderness corresponds to the area of
inflammation is almost an axiom of surgery. Pain and tenderness are due
to the irritation of nerve filaments of the part, rendered all the more
sensitive by the abnormal conditions of their blood supply. In
inflammatory conditions of internal organs, for example the abdominal
viscera, the pain is frequently referred to other parts, usually to an
area supplied by branches from the same segment of the cord as that
supplying the inflamed part.
For purposes of diagnosis, attention should be paid to the terms in
which the patient describes his pain. For example, the pain caused by
an inflammation of the skin is usually described as of a _burning_ or
_itching_ character; that of inflammation in dense tissues like
periosteum or bone, or in encapsuled organs, as _dull_, _boring_, or
_aching_. When inflammation is passing on to suppuration the pain
assumes a _throbbing_ character, and as the pus reaches the surface, or
"points," as it is called, sharp, _darting_, or _lancinating_ pains are
experienced. Inflammation involving a nerve-trunk may cause a _boring_
or a _tingling_ pain; while the implication of a serous membrane such as
the pleura or peritoneum gives rise to a pain of a sharp, _stabbing_
character.
_Interference with the function_ of the inflamed part is always present
to a greater or less extent.
#Constitutional Disturbances.#--Under the term constitutional
disturbances are included the presence of fever or elevation of
temperature; certain changes in the pulse rate and the respiration;
gastro-intestinal and urinary disturbances; and derangements of the
central nervous system. These are all due to the absorption of toxins
into the general circulation.
_Temperature._--A marked rise of temperature is one of the most constant
and important concomitants of acute inflammatory conditions, and the
temperature chart forms a fairly reliable index of the state of the
patient. The toxins interfere with the nerve-centres in the medulla that
regulate the balance between the production and the loss of body heat.
Clinically the temperature is estimated by means of a self-registering
thermometer placed, for from one to five minutes, in close contact with
the skin in the axilla, or in the mouth. Sometimes the thermometer is
inserted into the rectum, where, however, the temperature is normally
¾° F. higher than in the axilla.
_In health_ the temperature of the body is maintained at a mean of about
98.4° F. (37° C.) by the heat-regulating mechanism. It varies from hour
to hour even in health, reaching its maximum between four and eight in
the evening, when it may rise to 99° F., and is at its lowest between
four and six in the morning, when it may be about 97° F.
The temperature is more easily disturbed in children than in adults, and
may become markedly elevated (104° or 105° F.) from comparatively slight
causes; in the aged it is less liable to change, so that a rise to 103°
or 104° F. is to be looked upon as indicating a high state of fever.
A sudden rise of temperature is usually associated with a feeling of
chilliness down the back and in the limbs, which may be so marked that
the patient shivers violently, while the skin becomes cold, pale, and
shrivelled--_cutis anserina_. This is a nervous reaction due to a want
of correspondence between the internal and the surface temperature of
the body, and is known clinically as a _rigor_. When the temperature
rises gradually the chill is usually slight and may be unobserved. Even
during the cold stage, however, the internal temperature is already
raised, and by the time the chill has passed off its maximum has been
reached.
The _pulse_ is always increased in frequency, and usually varies
directly with the height of the temperature. _Respiration_ is more
active during the progress of an inflammation; and bronchial catarrh is
common apart from any antecedent respiratory disease.
_Gastro-intestinal disturbances_ take the form of loss of appetite,
vomiting, diminished secretion of the alimentary juices, and weakening
of the peristalsis of the bowel, leading to thirst, dry, furred tongue,
and constipation. Diarrhœa is sometimes present. The _urine_ is usually
scanty, of high specific gravity, rich in nitrogenous substances,
especially urea and uric acid, and in calcium salts, while sodium
chloride is deficient. Albumin and hyaline casts may be present in cases
of severe inflammation with high temperature. The significance of
general _leucocytosis_ has already been referred to.
#General Principles of Treatment.#--The capacity of the inflammatory
reaction for dealing with bacterial infections being limited, it often
becomes necessary for the surgeon to aid the natural defensive
processes, as well as to counteract the local and general effects of the
reaction, and to relieve symptoms.
The ideal means of helping the tissues is by removing the focus of
infection, and when this can be done, as for example in a carbuncle or
an anthrax pustule, the infected area may be completely excised. When
the focus is not sufficiently limited to admit of this, the infected
tissue may be scraped away with the sharp spoon, or destroyed by
caustics or by the actual cautery. If this is inadvisable, the organisms
may be attacked by strong antiseptics, such as pure carbolic acid.
Moist dressings favour the removal of bacteria by promoting the escape
of the inflammatory exudate, in which they are washed out.
#Artificial Hyperæmia.#--When such direct means as the above are
impracticable, much can be done to aid the tissues in their struggle by
improving the condition of the circulation in the inflamed area, so as
to ensure that a plentiful supply of fresh arterial blood reaches it.
The beneficial effects of _hot fomentations and poultices_ depend on
their causing a dilatation of the vessels, and so inducing a hyperæmia
in the affected area. It has been shown experimentally that repeated,
short applications of moist heat (not exceeding 106° F.) are more
efficacious than continuous application. It is now believed that the
so-called _counter-irritants_--mustard, iodine, cantharides, actual
cautery--act in the same way; and the method of treating erysipelas by
applying a strong solution of iodine around the affected area is based
on the same principle.
[Illustration: FIG. 6.--Passive Hyperæmia of Hand and Forearm induced by
Bier's Bandage.]
While these and similar methods have long been employed in the treatment
of inflammatory conditions, it is only within comparatively recent years
that their mode of action has been properly understood, and to August
Bier belongs the credit of having put the treatment of inflammation on a
scientific and rational basis. Recognising the "beneficent intention" of
the inflammatory reaction, and the protective action of the leucocytosis
which accompanies the hyperæmic stages of the process, Bier was led to
study the effects of increasing the hyperæmia by artificial means. As a
result of his observations, he has formulated a method of treatment
which consists in inducing an artificial hyperæmia in the inflamed area,
either by obstructing the venous return from the part (_passive
hyperæmia_), or by stimulating the arterial flow through it (_active
hyperæmia_).
_Bier's Constricting Bandage._--To induce a _passive hyperæmia_ in a
limb, an elastic bandage is applied some distance above the inflamed
area sufficiently tightly to obstruct the venous return from the distal
parts without arresting in any way the inflow of arterial blood (Fig. 6).
If the constricting band is correctly applied, the parts beyond
become swollen and œdematous, and assume a bluish-red hue, but they
retain their normal temperature, the pulse is unchanged, and there is no
pain. If the part becomes blue, cold, or painful, or if any existing
pain is increased, the band has been applied too tightly. The hyperæmia
is kept up from twenty to twenty-two hours out of the twenty-four, and
in the intervals the limb is elevated to get rid of the œdema and to
empty it of impure blood, and so make room for a fresh supply of healthy
blood when the bandage is re-applied. As the inflammation subsides, the
period during which the band is kept on each day is diminished; but the
treatment should be continued for some days after all signs of
inflammation have subsided.
This method of treating acute inflammatory conditions necessitates
close supervision until the correct degree of tightness of the band has
been determined.
[Illustration: FIG. 7.--Passive Hyperæmia of Finger induced by Klapp's
Suction Bell.]
_Klapp's Suction Bells._--In inflammatory conditions to which the
constricting band cannot be applied, as for example an acute mastitis, a
bubo in the groin, or a boil on the neck, the affected area may be
rendered hyperæmic by an appropriately shaped glass bell applied over it
and exhausted by means of a suction-pump, the rarefaction of the air in
the bell determining a flow of blood into the tissues enclosed within it
(Figs. 7 and 8). The edge of the bell is smeared with vaseline, and the
suction applied for from five to ten minutes at a time, with a
corresponding interval between the applications. Each sitting lasts for
from half an hour to an hour, and the treatment may be carried out once
or twice a day according to circumstances. This apparatus acts in the
same way as the old-fashioned _dry cup_, and is more convenient and
equally efficacious.
[Illustration: FIG. 8.--Passive Hyperæmia induced by Klapp's Suction
Bell for Inflammation of Inguinal Gland.]
_Active hyperæmia_ is induced by the local application of heat,
particularly by means of hot air. It has not proved so useful in acute
inflammation as passive hyperæmia, but is of great value in hastening
the absorption of inflammatory products and in overcoming adhesions and
stiffness in tendons and joints.
_General Treatment._--The patient should be kept at rest, preferably in
bed, to diminish the general tissue waste; and the diet should be
restricted to fluids, such as milk, beef-tea, meat juices or gruel, and
these may be rendered more easily assimilable by artificial digestion if
necessary. To counteract the general effect of toxins absorbed into
the circulation, specific antitoxic sera are employed in certain forms
of infection, such as diphtheria, streptococcal septicæmia, and tetanus.
In other forms of infection, vaccines are employed to increase the
opsonic power of the blood. When such means are not available, the
circulating toxins may to some extent be diluted by giving plenty of
bland fluids by the mouth or normal salt solution by the rectum.
The elimination of the toxins is promoted by securing free action of the
emunctories. A saline purge, such as half an ounce of sulphate of
magnesium in a small quantity of water, ensures a free evacuation of the
bowels. The kidneys are flushed by such diluent drinks as equal parts of
milk and lime water, or milk with a dram of liquor calcis saccharatus
added to each tumblerful. Barley-water and "Imperial drink," which
consists of a dram and a half of cream of tartar added to a pint of
boiling water and sweetened with sugar after cooling, are also useful
and non-irritating diuretics. The skin may be stimulated by Dover's
powder (10 grains) or liquor ammoniæ acetatis in three-dram doses every
four hours.
Various drugs administered internally, such as quinine, salol,
salicylate of iron, and others, have a reputation, more or less
deserved, as internal antiseptics.
Weakness of the heart, as indicated by the condition of the pulse, is
treated by the use of such drugs as digitalis, strophanthus, or
strychnin, according to circumstances.
Gastro-intestinal disturbances are met by ordinary medical means.
Vomiting, for example, can sometimes be checked by effervescing drinks,
such as citrate of caffein, or by dilute hydrocyanic acid and bismuth.
In severe cases, and especially when the vomited matter resembles
coffee-grounds from admixture with altered blood--the so-called
post-operative hæmatemesis--the best means of arresting the vomiting is
by washing out the stomach. Thirst is relieved by rectal injections of
saline solution. The introduction of saline solution into the veins or
by the rectum is also useful in diluting and hastening the elimination
of circulating toxins.
In surgical inflammations, as a rule, nothing is gained by lowering the
temperature, unless at the same time the cause is removed. When severe
or prolonged pyrexia becomes a source of danger, the use of hot or cold
sponging, or even the cold bath, is preferable to the administration of
drugs.
_Relief of Symptoms._--For the relief of _pain_, rest is essential. The
inflamed part should be placed in a splint or other appliance which will
prevent movement, and steps must be taken to reduce its functional
activity as far as possible. Locally, warm and moist dressings, such as
a poultice or fomentation, may be used. To make a fomentation, a piece
of flannel or lint is wrung out of very hot water or antiseptic lotion
and applied under a sheet of mackintosh. Fomentations should be renewed
as often as they cool. An ordinary india-rubber bag filled with hot
water and fixed over the fomentation, by retaining the heat, obviates
the necessity of frequently changing the application. The addition of a
few drops of laudanum sprinkled on the flannel has a soothing effect.
Lead and opium lotion is a useful, soothing application employed as a
fomentation. We prefer the application of lint soaked in a 10 per cent.
aqueous or glycerine solution of ichthyol, or smeared with ichthyol
ointment (1 in 3). Belladonna and glycerine, equal parts, may be used.
Dry cold obtained by means of icebags, or by Leiter's lead tubes through
which a continuous stream of ice-cold water is kept flowing, is
sometimes soothing to the patient, but when the vessels in the inflamed
part are greatly congested its use is attended with considerable risk,
as it not only contracts the arterioles supplying the part, but also
diminishes the outflow of venous blood, and so may determine gangrene of
tissues already devitalised.
A milder form of employing cold is by means of evaporating lotions: a
thin piece of lint or gauze is applied over the inflamed part and kept
constantly moist with the lotion, the dressing being left freely exposed
to allow of continuous evaporation. A useful evaporating lotion is made
up as follows: take of chloride of ammonium, half an ounce; rectified
spirit, one ounce; and water, seven ounces.
The administration of opiates may be necessary for the relief of pain.
The accumulation of an excessive amount of inflammatory exudate may
endanger the vitality of the tissues by pressing on the blood vessels to
such an extent as to cause stasis, and by concentrating the local action
of the toxins. Under such conditions the tension should be relieved and
the exudate with its contained toxins removed by making an incision into
the inflamed tissues, and applying a suction bell. When the exudate has
collected in a synovial cavity, such as a joint or bursa, it may be
withdrawn by means of a trocar and cannula. There are other methods of
withdrawing blood and exudate from an inflamed area, for example by
leeches or wet-cupping, but they are seldom employed now.
Before applying leeches the part must be thoroughly cleansed, and if
the leech is slow to bite, may be smeared with cream. The leech is
retained in position under an inverted wine-glass or wide test-tube till
it takes hold. After it has sucked its fill it usually drops off, having
withdrawn a dram or a dram and a half of blood. If it be desirable to
withdraw more blood, hot fomentations should be applied to the bite. As
it is sometimes necessary to employ considerable pressure to stop the
bleeding, leeches should, if possible, be applied over a bone which will
furnish the necessary resistance. The use of styptics may be called for.
_Wet-cupping_ has almost entirely been superseded by the use of Klapp's
suction bells.
_General blood-letting_ consists in opening a superficial vein
(venesection) and allowing from eight to ten ounces of blood to flow
from it. It is seldom used in the treatment of surgical forms of
inflammation.
_Counter-irritants._--In deep-seated inflammations, counter-irritants
are sometimes employed in the form of mustard leaves or blisters,
according to the degree of irritation required. A mustard leaf or
plaster should not be left on longer than ten or fifteen minutes, unless
it is desired to produce a blister. Blistering may be produced by a
_cantharides plaster_, or by painting with _liquor epispasticus_. The
plaster should be left on from eight to ten hours, and if it has failed
to raise a blister, a hot fomentation should be applied to the part.
_Liquor epispasticus_, alone or mixed with equal parts of collodion, is
painted on the part with a brush. Several paintings are often required
before a blister is raised. The preliminary removal of the natural
grease from the skin favours the action of these applications.
The treatment of inflammation in special tissues and organs will be
considered in the sections devoted to regional surgery.
#Chronic Inflammation.#--A variety of types of chronic and subacute
inflammation are met with which, owing to ignorance of their causations,
cannot at present be satisfactorily classified.
The best defined group is that of the _granulomata_, which includes such
important diseases as tuberculosis and syphilis, and in which different
types of chronic inflammation are caused by infection with a specific
organism, all having the common character, however, that abundant
granulation tissue is formed in which cellular changes are more in
evidence than changes in the blood vessels, and in which the subsequent
degeneration and necrosis of the granulation tissue results in the
breaking down and destruction of the tissue in which it is formed.
Another group is that in which chronic inflammation is due to mild or
attenuated forms of pyogenic infection affecting especially the lymph
glands and the bone marrow. In the glands of the groin, for example,
associated with various forms of irritation about the external genitals,
different types of _chronic lymphadenitis_ are met with; they do not
frankly suppurate as do the acute types, but are attended with a
hyperplasia of the tissue elements which results in enlargement of the
affected glands of a persistent, and sometimes of a relapsing character.
Similar varieties of _osteomyelitis_ are met with that do not, like the
acute forms, go on to suppuration or to death of bone, but result in
thickening of the bone affected, both on the surface and in the
interior, resulting in obliteration of the medullary canal.
A third group of chronic inflammations are those that begin as an acute
pyogenic inflammation, which, instead of resolving completely, persists
in a chronic form. It does so apparently because there is some factor
aiding the organisms and handicapping the tissues, such as the presence
of a foreign body, a piece of glass or metal, or a piece of dead bone;
in these circumstances the inflammation persists in a chronic form,
attended with the formation of fibrous tissue, and, in the case of bone,
with the formation of new bone in excess. It will be evident that in
this group, chronic inflammation and repair are practically
interchangeable terms.
There are other groups of chronic inflammation, the origin of which
continues to be the subject of controversy. Reference is here made to
the chronic inflammations of the synovial membrane of joints, of tendon
sheaths and of bursæ--_chronic synovitis_, _teno-synovitis_ and
_bursitis_; of the fibrous tissues of joints--chronic forms of
_arthritis_; of the blood vessels--chronic forms of _endarteritis_ and
of _phlebitis_ and of the peripheral nerves--_neuritis_. Also in the
breast and in the prostate, with the waning of sexual life there may
occur a formation of fibrous tissue--chronic _interstitial mastitis_,
_chronic prostatitis_, having analogies with the chronic interstitial
inflammations of internal organs like the kidney--_chronic interstitial
nephritis_; and in the breast and prostate, as in the kidney, the
formation of fibrous tissue leads to changes in the secreting epithelium
resulting in the formation of cysts.
Lastly, there are still other types of chronic inflammation attended
with the formation of fibrous tissue on such a liberal scale as to
suggest analogies with new growths. The best known of these are the
systematic forms of fibromatosis met with in the central nervous system
and in the peripheral nerves--_neuro-fibromatosis_; in the submucous
coat of the stomach--_gastric fibromatosis_; and in the
colon--_intestinal fibromatosis_.
These conditions will be described with the tissues and organs in which
they occur.
In the _treatment of chronic inflammations_, pending further knowledge
as to their causation, and beyond such obvious indications as to help
the tissues by removing a foreign body or a piece of dead bone, there
are employed--empirically--a number of procedures such as the induction
of hyperæmia, exposure to the X-rays, and the employment of blisters,
cauteries, and setons. Vaccines may be had recourse to in those of
bacterial origin.