Causes, cold, damp, soils and exposures, as with rheumatism, youth,
vigor, heavy diet, digestion, or hepatic disorder, over-exertion,
perspiration and succeeding chill, wading or swimming rivers, standing
in snow, salted snow, rain, sleet, snow, draughts between open doors
and windows, clipping, cold sponging of legs, tuberculosis, a common
cause in man and cattle is rare in horses, surface pneumonias,
cancers, actinomycosis, tumors. Traumas from broken rib, penetrating
intercostal wound, blows, contusions, ruptured pulmonary or
intercostal abscess. Irritant (infectious) exudate suggests microbes.
Symptoms, chill, reaction, partial sweats, pawing, pointing one foot,
hyperthermia, hard, jarring pulse, hurried breathing, inspiration
catching, pleuritic ridge, uneasy movements, hacking cough, tumors and
twitching of chest muscles, tender intercostals, grunting, friction
sound, subsiding with appearance of dull area below, signs of
effusion, relief, dyspnœa, lifting flanks and loins, perspirations,
stocking limbs, pasty swelling on sternum, effusion of same level on
both sides, creaking sounds, splashing, gurgling, metallic tinkling,
weakness, sinking. Signs of adhesions, compression of lung, abscess.
Duration. Lesions, early formation of false membranes, pleuritic
effusion, its composition, its color at different stages, dry
pleurisy, sero-fibrinous, sero-fibro-purulent, hydro-pneumothorax,
tubercle. Prognosis. Treatment, during the chill, warm air, clothing,
drinks, injections, compresses, pilocarpin during early inflammatory
stage, derivatives, dry cupping, mustard, cantharides, hot water, or
air, cold applications, laxatives, calmatives, antirheumatics,
alkaline agents, with bitters, diuretics, heart tonic, iodine,
mercury, thoracentesis.
_Causes._ Pleurisy is common in all domestic animals and especially so
in cold, damp, exposed localities which suffer equally from rheumatism.
It occasionally extends to the fascia of the limbs, the joints, or the
navicular or other trochlea as a rheumatic affection. The disease is
prevalent among young and vigorous horses, four or five years old, on
stimulating feeding. Here hepatic derangements and poisons,
over-exertion, perspiration and succeeding chills are especially to be
suspected. Plunging the limbs in ice cold water as in wading a river
(Fromage), standing in snow and above all in salted snow, or facing a
cold rain, sleet, or snow when perspiring or fatigued, are recognized
causes. A full drink of ice cold water when freely perspiring, and
followed by standing in the frosty air, or in a cold current indoors.
Exposure unblanketed after clipping in winter (Field, Trasbot), and even
sponging the body or legs with cold water when heated or fatigued or
both. St. Cyr found that pneumonias stood to pleurisies as 3: 1, Trasbot
as 10: 1, yet the latter draws attention to the fact that in cavalry
horses habituated to the stable and sent out into camps in the depth of
winter, the pleurisies are more numerous than pneumonias. This may
suffice to show the importance of the rôle filled by cold and chill in
the production of pleurisy. Yet many physicians look upon the chill as a
predisposition only, while the true origin of disease is microbian. And
in man a large proportion of pleurisies appear to be distinctly
tuberculous. Bowditch traced 90 cases of acute pleurisy and found that
32 had tuberculosis. The objection to generalizing too largely on this
for the lower animals is that the horse and dog, in which tuberculosis
is rare, are by far the most common subjects of pleurisy, whilst cows
which are very prone to tuberculosis show few cases of simple pleurisy.
Again we find pleurisy in the horse as the result of other diseases
localized in or adjacent to the pleura, and where there is nothing to
indicate tuberculosis. Thus it follows pneumonia approaching the surface
of the lung, cancers, actinomycosis and other tumors, and traumas—a
pulmonary abscess bursting into the pleura, a broken rib scratching and
lacerating the lung, a perforating wound of the intercostal space, or in
cattle a sharp pointed body advancing from the reticulum toward the
heart.
But the presumptive absence of the tubercle bacillus in the great
majority of pleurisies in the horse does not prove the absence of all
pathogenic microbes. Trasbot, who rejects the microbian theory, found
that the injection of a little of the exudate into the pleural cavity of
a sound horse, always determined a generalized pleurisy. Injections of
distilled water with the same antiseptic precautions, made separately by
himself and Laborde, had no pathogenic effect. Trasbot attributes the
pleurisy vaguely, to the irritant effect of the exudate, but if it
should finally be shown that this exudate contains microbes, though they
may not be those of tuberculosis, the irritant action will be much more
clearly explained. There are forms of pleurisy which are unquestionably
the result of microbes, as in lung plague, influenza, canine distemper,
glanders, tuberculosis, pneumo-enteritis, actinomycosis, and
theoretically it might be supposed that in our ordinary acute
pleurisies, other germs that have been lurking harmless in the system
may take occasion by reason of the lowered vitality induced by a chill,
or a trauma, to colonize the thoracic serosa and develop pleurisy. Under
such a theory, the predisposing and microbian element would remain
equally effectual, but only operative when conjoined, neither being
pathogenic without the other.
Until the constancy of the microbian factor is demonstrated we must
recognize the time honored doctrine, that pleurisy may be due to cold,
exposure, over exertions, to traumatic injuries, blows, concussions,
fractures, penetrating wounds, and to extension by contiguity from
adjacent diseases.
Most commonly pleurisy is unilateral on the right side but is often on
the left or on both sides.
_Symptoms._ There is the early symptom of shivering followed by a hot
stage in which the limbs participate and partial sweats bedew the
surface. There are first uneasy movements of the fore limbs with some
lifting of the flanks and this discomfort increases until the patient is
panting with pain and occasionally glancing round at his heaving flanks
and even pawing as in colic. If the pleurisy is confined to one side the
corresponding fore limb is often advanced before the other. The
temperature is 102° and upward. The pulse is quick, hard and
incompressible being usually compared to a jarred wire and beats from 48
to over 60 per minute. The breathing is highly characteristic. It is
hurried, is carried on chiefly by the abdominal muscles to avoid the
rubbing of the inflamed pleuræ on each other, and has the inspiration
short and suddenly checked by an audible closure of the glottis while
the expiration is slow and prolonged. This character of the breathing is
well observed when the ear is placed against the false nostril. The
laboring abdominal muscles stand out as a ridge from the outer angle of
the ilium along the lower ends of the last ribs (pleuritic ridge). A
tremor on this line is often noticeable in the early stages. It may also
be felt by the hand laid on the costal region. The horse does not stand
obstinately still as in pneumonia, but frequently moves as if seeking an
easier posture. The short, hacking cough contrasts with the deep, rare
cough of pneumonia. The expired air is not so hot, nor the mucous
membrane of the nose so red as in the last named disease and there is no
nasal discharge. A twitching of the muscles of the chest is sometimes
seen and if the intercostal muscles are pressed upon, the animal winces
and frequently grunts. This last symptom is likewise seen in rheumatic
disease of the intercostal muscles (pleurodynia) but the absence of the
fever, the cough, and other chest symptoms sufficiently distinguish
this. Auscultation detects in the early stages in addition to a healthy
respiratory murmur, a friction sound audible in inspiration only in
short jerks near the close of the act and comparable to the rubbing of
the palm of one hand over the other laid over the ear, but this is no
longer heard when effusion of liquid has taken place into the pleuræ.
Percussion in the early stages detects no change from the healthy chest
resonance.
If not relieved in from twenty-four to thirty-six hours, a remarkable
modification of the symptoms takes place indicating the occurrence of
effusion. The violent symptoms are suddenly relieved. The quick catching
breathing which is in many cases accompanied by a grunt, becomes easy
and though fuller than natural is comparatively regular. In particular
the inspiration is free and full and comparatively painless, the sudden
check and the grunt by which it was arrested having alike disappeared.
The tension of the abdominal muscles and the tucked up appearance of the
flanks give way; the pulse acquires a softer character, the haggard
pinched countenance is relaxed, and a general appearance of comfort and
even liveliness prevades the animal. This temporary improvement is often
so great that the horse will take to feeding as if he had all at once
recovered.
The apparent recovery is, however, only transient. Soon the pulse
becomes more frequent and loses its fulness, the breathing is more
laborious and attended with a characteristic lifting of the flanks and
loins, the nostrils are widely dilated, the limbs outstretched and the
elbows outturned, the eyes stare and project and the countenance has a
haggard appearance indicating threatened suffocation. Partial sweats may
break out on the surface, due to the state of nervous excitement and
general relaxation and supplementing in some degree the impaired
exhalation from the lungs. Auscultation over the lower region of the
chest shows a complete absence of the respiratory murmur, rising to the
same level precisely at all points. Percussion elicits no resonance on
the same region. If the effusion has taken place slowly or existed for
some time, the dulness and absence of sound will usually indicate that
the liquid rises to the same level on both sides. So thin and permeable
is the posterior mediastinum in its lower part that unless thickly
coated by new solid exudations, the effusion readily passes through it
and rises to the same height on both sides. If gas as well as liquid is
produced in the pleural sac a gurgling or splashing sound may be heard
on auscultation, and occasionally, after rising or other change of
position, a _metallic tinkling_, due to droppings from the shreds of
false membranes above into the fluid below.
As the disease proceeds dropsical effusions are observed beneath the
skin of the breast and abdomen, a mucous rattle is heard in the trachea,
the nose, ears and limbs become cold, the pulse increases in rapidity
and weakness, shows the distinct anæmic tremor or thrill, and becomes
rapidly imperceptible; the horse moves unsteadily and often falls
suddenly dead.
This early fatality is, however, only seen in the worst cases. In those
about to terminate favorably improvement is shown usually about the
fourth day. The lifting of the flanks and loins becomes moderated, the
ribs move more freely, the grunt ceases, the pulse is fuller, softer and
less frequent, and auscultation and percussion show a steady decrease in
the effusion. Appetite meanwhile returns, the horse moves more freely,
lies down for a length of time in succession, and convalescence lasts
from two to three weeks.
In the less fortunate cases structural changes more or less permanent,
keep up symptoms of illness for a variable length of time. Sometimes
after the liquid effusion has been absorbed the lung remains attached to
the side of the chest by newly formed tissue (false membrane) and while
this is undergoing a drying and organizing process, it gives rise to a
leathery, creaking sound heard on auscultation and easily mistaken for
crepitation. Sometimes an abscess forms on the surface of the pleura or
in the newly organized false membrane, and either bursts into the
pleural sac (empyema) where it serves to increase and sustain the
irritation, or it makes its way through the intercostal spaces and is
discharged externally. In this last case its advance toward the surface
is heralded by an extensive inflammatory infiltration and pasty swelling
much more tender to the touch than the dropsical swelling already
referred to. Another condition is that in which false membranes of
considerable thickness invest a lung and, following the law of all
fibrous structures in process of organization, they contract and cause a
compression and partial collapse of the contained lung tissue. A
flattening of the corresponding side of the chest and a muffled and
almost inaudible respiratory murmur is the result of this condition. In
some measure these symptoms are present during convalescence in all
cases of pleurisy since the lung never expands to its full size till
some time after apparent recovery, but it is only when the organ is
invested with false membrane that the symptoms are very apparent.
In all such cases of prolonged pleurisy from protracted structural
change there is continued illness without the violent symptoms by which
the acute form of the disease is manifested. The acute suffering, the
restlessness, the grunt, and even the catching breathing may be absent;
the temperature may be almost reduced to the healthy standard, the pulse
small and tolerably soft, the appetite considerably improved and the
different secretions tolerably normal; yet the pinching of the
intercostal spaces causes sharp pain, and measurement, auscultation and
percussion testify to the persistence of disease. The animal is
hidebound, unthrifty and unequal to any exertion. The cough is weak and
painful and sometimes accompanied by a grunt.
Besides the changes connected with exudation and effusion, and
organization or suppuration in the exuded products, _gangrene_ sometimes
results. A case of this kind is related by _Percivall_.
The _duration_ of pleurisy may thus extend from two days in very acute
cases to several weeks, or even months if we estimate it by the
continuance of _hydrothorax_ in the chronic cases.
_Post Mortem Appearances._ These consist mainly in the presence of false
membranes lining the pleura and hanging in cobweblike shreds into the
cavity of the chest, and of the liquid effusion which fills up the chest
at its most dependent part. The pericardium also contains fluid in many
cases. The periods at which exudation takes place, and when the
principal changes take place in the exuded materials have been well
investigated by Dupuy, Hamont, Delafond and St. Cyr. They induced
pleurisy by injecting irritant liquids into the chest, and noted the
regular sequence of changes.
Dupuy injected two drachms of oxalic acid dissolved in three ounces of
water. Symptoms of pleurisy at once came on, with the friction sound
characteristic of its early stages. Next day friction sound had ceased
and evidence of effusion existed. The same experiment repeated on
several horses showed that if killed at any period subsequently to this,
considerable exudation had already taken place. In one horse in which
the disease was of 50 hours’ standing the chest contained 43 pints of
citrine-colored fluid, and abundance of yellow, thick, false membrane
enveloping the costal and pulmonary pleuræ.
Hamont injected seven ounces of a weak solution of tartaric acid into
the left pleural sac, repeated the injection next morning and destroyed
the horse twenty minutes afterward. The chest opened immediately showed
a small amount of liquid on the affected side, and the pleura injected
and reddened.
Delafond made twenty-two experiments with the same general result.
Percivall found recent adhesions between the lungs and side so early as
seventeen hours after the commencement of the pleurisy.
Andral injected rabbits with acetic acid and in nineteen hours found in
the injected pleura soft, thin, false membranes traversed by red
anastomosing lines, and in certain cases a serous or puriform fluid.
W. Williams found a false membrane formed twenty-four hours after the
injection of the irritant.
St. Cyr in a series of 43 experimental and casual pleurisies in horses,
found that in a very few hours there was marked local congestion and
swelling of the pleura speedily followed by the formation of soft,
pulpy, friable false membranes, largely amorphous and granular but
impregnated with many cells and nuclei. These adhere feebly to the
pleura but may accumulate with prodigious rapidity so as to cover in
three or four days the whole pleural surface on one or both sides. The
attendant serous effusion was bloody, turbid, or lactescent. The pleural
surface under the false membrane was highly vascular and studded with
fragile, red conical elevations projecting into the membrane.
Exceptionally the sub-serous connective tissue became the seat of
exudation as well.
From the sixth to the ninth day the false membranes began to become
vascular and from the tenth to the fourteenth day commenced to organize
into the connective tissue. With the advent of this stage, the
inflammatory action tended to subside, and the reabsorption and repair
to ensue.
_Pleuritic effusion._ This varies greatly at the different stages of the
disease. As effused it has a composition resembling that of the blood:—
Water, 911 to 924
Albumen, 63.33 to 82.50
Fibrine formers, 2.16 to 12.50
Extractive matter.
Salts.
The progressive changes from the hæmorrhagic effusion to the limpid
hydrothorax and their relation to the different stages of the disease
and the subsidence of the inflammation are of the greatest importance in
deciding questions of responsibility, when the animal has recently
changed hands. St. Cyr has classified his cases in the following
instructive table:
─────────────────────┬─────────────────────────────────────────┬───────
Duration of the │ │
Disease. │ Effusions. │Total.
─────────────────────┼──────┬─────────────────┬────────┬───────┼───────
│ Port │ │Muddy or│ │
│Wine. │Sero-sanguineous.│Grayish.│Limpid.│
─────────────────────┼──────┼─────────────────┼────────┼───────┼───────
From 1st to 7th day.│ 9│ 6│ 3│ │ 18
„ 8th to 15th day. │ 2│ 3│ 4│ 6│ 15
„ 16th to 30th day. │ │ 1│ 1│ 5│ 7
After 30th day. │ │ │ │ 3│ 3
─────────────────────┼──────┼─────────────────┼────────┼───────┼───────
│ 11│ 10│ 8│ 14│ 43
─────────────────────┴──────┴─────────────────┴────────┴───────┴───────
Up to the 7th day 50 per cent. were dark red; after the 7th day only
13.3 per cent.; and after the 15th day none. Up to the 7th day 83.3 per
cent. were either dark red or sero-sanguineous and not one had attained
to translucency. After the 7th day only 8 per cent. were of port wine
hue, and by the 15th day 24 per cent. of all cases of over seven days
standing were already transparent. Of all cases of over 15 days
standing, 80 per cent. were perfectly translucent and none showed the
dark red hue. Finally after the 30th day all remaining cases were
limpid. This of course must not be applied with the same confidence in
both directions. While translucency of the effusion bespeaks seven days
standing and probably fifteen or twenty, the dark red hue must not be
held to imply a recent date for the attack. A relapse in the course of
convalescence may easily and quickly stain anew a liquid that was
already limpid, or had advanced far toward this condition.
The appearance of the lung tissue in a case of confirmed pleurisy is
characteristic. The lung is of a dull red color, shrunken, slightly
collapsed, flabby, scarcely crepitant under pressure and heavier than
water or floating in water. It is tough, not friable like hepatized
lung, and its cut surface is dry, smooth, and presents the interlobular
septa very well marked. This is due to the compression by effused
liquid, and by the organizing and contracting false membranes covering
the lung and implies nothing more than simple condensation. The air cell
may be collapsed, but contains no new product and has not parted with
its epithelium and the lung can be inflated through the bronchia.
_Differentiation according to the nature of the effusion._ Pathologists
have divided acute pleurisy into the _dry_, _sero-fibrinous_, and
_sero-fibro-purulent_.
=1. Dry or fibrinous pleurisy= has usually a more acute type and the
exudate containing an excess of the fibrinogenous elements forms a
coagulum or false membrane on the affected surface tending to bind that
to the part adjacent—the lungs to the costal pleura. The serum, small in
quantity, is in the main retained in the exudate or if set free is
actively reabsorbed by the healthy pleura.
=2. Sero-fibrinous pleurisy.= This form is usually less acute and more
extended involving perhaps an entire pleural sac, or even both sides of
the chest. This is the common form of pleurisy and is that referred to
in the experiments of St. Cyr and others above. The earliest lesions in
experimental cases (with chloride of zinc solution) in dogs are an
uniform bright red congestion, with a bright, shining surface as yet
perfectly dry. There is already shedding of patches of the endothelial
cells, swelling and proliferation of the superficial connective tissue
cells and the formation of a few pus globules. This is seen in from half
an hour to six hours after the application of the irritant.
Next follows the exudation of fibrine and serum, which respectively
coagulate as false membrane on the inflamed membrane, or drop to the
bottom of the sac as liquid. The fibrine appears as granules, little
knobs and threads between and on the endothelial cells and entangling a
few pus cells. The changes are now much more marked in the connective
tissue cells, which are more numerous, larger, nucleated and often
stellate or polygonal. Changes are well advanced in twenty-four hours.
The cells go on increasing to the fourth or fifth day, when new blood
vessels are formed into the membrane and may be injected from the
pleura. From this time, in favorable cases absorption of the liquid
proceeds, and the fibrine is organized, and by the fourteenth day is
transformed into connective tissue, the superficial cells forming
endothelium and the deeper, branching connective tissue cells. The
result is the thickening of the pleura and the formation of adhesions.
The case, however, may prove fatal, or it may be protracted through the
continued production of fibrine and serum, or it may pass into empyema.
=3. Sero-fibrino-purulent pleurisy.= =Empyema.= This is usually very
dangerous as well as complicated. It may supervene on the last described
form. It may depend on rupture into the pleura of abscess of the lung,
bronchial glands, liver, diaphragm or intercostal space and the
infection of the chest cavity. It may in the same way follow the
laceration of a bronchium by a broken rib, the perforation of the
intercostal space by a foreign body, or (in cattle) the penetration of
the chest by a sharp pointed body from the reticulum. It may follow at
once on pleurisy of a very high grade. Probably in all such cases there
is infection of the pleura by pus microbes. When there is a
communication with a bronchium, the reticulum or the external air there
are usually septic germs in addition, and the contents of the chest
become fœtid.
The purulent fluid may accumulate in the lower part of the pleural sac,
or it may be confined in abscess form in the false membrane, and extend
thence into surrounding tissues. The pus-containing pleura, or cavity
infected by the pus germs, assumes the appearance of a granulating
surface, or of the lining membrane of an abscess, and continues to
produce pus in greater or less amount.
The formation of pus in the pleura is known as _empyema_. When air
enters the pleura through a wound perforating the chest wall, or when
gas is formed in the pleura, the condition is =pneumothorax=. As liquid
is usually present as well it is =hydro-pneumothorax=.
Tubercular and other forms of pleurisy have in certain cases been
superadded to the specific local lesions, by which such diseases are
individually characterized.
_Prognosis._ Occurring in an otherwise healthy system and especially if
confined to one side of the chest, pleurisy is not frequently fatal, and
under appropriate treatment recovery is oftentimes rapid and
satisfactory. A certain number of cases merge into chronic hydrothorax,
the inflammation apparently subsiding, but reabsorption failing to take
place. The hydrothorax may last for months or even a year.
_Treatment._ If seen during the _chill_ and before inflammation has been
definitely established every effort must be directed to secure its
abortion, if possible. No time should be lost in placing the patient in
a warm comfortable stall or box, covering him with woolen blankets and
actively rubbing and loosely flannel bandaging the legs. Warm drinks and
warm injections must be given. Half an ounce or an ounce of camomile or
boneset in infusion in two or three quarts of hot water, or in the
absence of this any of the carminatives, or etherial, alcoholic or
ammoniacal stimulants may be given. Pilocarpin in 7 grain dose
hypodermically may promptly secure a revulsion of blood to the skin and
at once overcome the chill and prove a most effective derivative from
the pleura. Placing the legs in buckets of hot water, or the whole
animal in a hot air bath will often act equally well. Packing the chest
and even the abdomen in a blanket wrung out of very hot water and
covering it closely by one or two dry ones, or, better still, by a
rubber or other impermeable covering, will long retain both heat and
moisture, securing free cutaneous circulation, and soothing in a most
effective way the irritation in the chest. This may be maintained as
long as requisite to relieve the patient, and then the body may be
uncovered, a part at a time, rubbed dry and covered with a dry woolen
blanket. By using elastic circingles over the compress they are adapted
to the respiratory movements and any restriction in the movement of the
ribs is beneficial by limiting the friction, pain and irritation in the
pleura.
In the second stage, when inflammation has already set in, the same
general measures of derivation toward the skin and hot bath or soothing
derivative compress are still demanded though they may be substituted by
more stimulating derivatives. The bleeding of the patient into his own
vessels is sought in various ways. On the continent of Europe
stimulating embrocations (essential oils, ammonia and oil, mustard,
etc.) are applied to the limbs. In America and England similar agents
are more commonly applied to the walls of the chest and dry cupping in
the same region has been resorted to. Metallic cups with small mouths
and having a capacity of about a pint each, have the air rarefied by
plunging into each a spirit lamp, and, on its withdrawal, suddenly
applying the mouth of the cup on the skin of the costal region
previously well coated with lard. Another form of cup is made with a
tube and stopcock in its otherwise blind end by means of which it is
exhausted with a syringe after its mouth has been applied to the skin.
In the absence of both a narrow mouthed glass tumbler may be employed,
the air is rarefied by inserting into it a burning spill of paper or
wood for a few seconds and on its withdrawal the cup is instantly
inverted on the skin. If the animal is very hairy or very thin it may be
necessary to shave the part, and smear with oil and even to select a
very narrow mouthed cup. When applied the cup is cooled with water or
otherwise and owing to the partial vacuum the skin is strongly drawn up
into it and the blood accumulates in and under the skin. It may be kept
on for half an hour at a time and with ten or twelve cups on one side
the patient tends to profuse perspiration establishing a strong
revulsion toward the skin, and great relief. In dangerous cases three or
four applications may be required in twenty-four hours.
Next to this the mustard application is perhaps the safest and most
valuable. The best ground mustard (black by preference) is made into a
very thin pulp with tepid or cold (never hot nor boiling) water and
rubbed in against the hair so as to soak the surface of the skin; it is
then closely covered with paper and with a rubber or other impervious
covering or, in default of better, with a close blanket and left on for
two hours. By this time the skin should be thickened to the extent of at
least a quarter of an inch and the derivation and relief will be very
manifest.
Cantharides is sometimes used but like most other severe irritants, is
liable to induce sympathetic irritation in an already severely inflamed
pleura, and thus to obviate all benefit. Cantharides is also liable
through extensive absorption to irritate the kidneys. To counteract this
Bouley gave ½ drachm doses of camphor with alleged good effect.
Some practitioners make local applications of hot water and of aqua
ammonia (confined) but unless very closely watched these are liable to
destroy the hair follicles and produce permanent blemish.
The hot air, steam bath, and hot compress have the advantage over the
mere irritant derivatives that their action is from first to last
soothing and free from all risk of inducing sympathetic irritation and
yet as derivatives they are eminently efficient. Next to them in safety
and efficacy comes dry cupping.
The irritant derivatives are often the most valuable, but must be used
with great judgment. They are always dangerous when the pleural
inflammation runs very high and when the local irritation and suffering
are specially acute. Under such circumstances it is usually desirable to
adopt other measures to moderate the severity of the inflammation, and
to fall back on baths, compresses and cups until the irritation is
alleviated before vegetable or animal vesicants are resorted to. In
acute and severe attacks these latter are especially applicable to the
early stages before the inflammation has been fully formed, or after the
stage of free effusion has set in.
With high fever and no benefit from hot local applications, cold
irrigation or refrigerant compresses to the walls of the chest, have
proved useful, but considering the rôle filled by cold in causation and
the suggested relation between pleurisy and rheumatism this is not to be
followed as a general practice.
If the patient has been a hearty feeder and if there is evident
costiveness a purgative (aloes or sulphate of soda) is often desirable
at the outset, but if the disease is of a low type this is always
dangerous, owing to susceptibility of the intestinal mucosa and it is
safer to correct constipation by injections or at most by a pint of
olive oil.
When the suffering is very acute and is aggravating the fever, a
hypodermic injection of morphine will often greatly relieve and even
favor a revulsion of blood toward the skin, but as it tends to suppress
the action of both bowels and kidneys it should be avoided unless it
seems absolutely necessary, and above all it should not be given by the
stomach. Cocaine hypodermically may be used to relieve pain.
Both fever and suffering can sometimes be greatly relieved by large
doses (2 drachms 3 or 4 times daily) of salicylate of soda, which again
suggests a close relation of the disease to rheumatism. Acetanilid or
phenacetin may be used to fill the same indication.
Next come the questions of alkaline and diuretic treatment. Some cases
do well if given nitrate of potash freely in the drinking water. Some
prefer the alkaline diuretics, such as acetate of potash or ammonia,
bicarbonate of potash or soda, biborate of soda, or the vegetable
diuretics such as colchicum, squills, etc. Fraënkel found that, while
comparatively ineffective alone, these proved most efficient (in man)
when combined with cinchona or other bitter. The hint should be useful
to the veterinarian. Diuretics in the stage of effusion should be pushed
as far as the strength of the patient will warrant.
Friedberger and Fröhner recommend pilocarpin, and no agent produces an
equal secretion from the natural emunctories and an equal tendency to
reabsorption. It is however so profoundly exhausting that it must be
used with the greatest judgment and caution.
Digitalis has often an excellent effect. Though not primarily a
diuretic, it is a powerful tonic of the heart and circulation, and by
increasing the blood tension it usually produces a free flow of urine.
In combination with the diuretic salts it may be used from the first but
it is especially valuable, after effusion and when attention must be
given mainly to securing reabsorption. Care is demanded that we avoid
its cumulative action, and in place of continuous large doses, a strong
infusion applied over the loins will sometimes have a good effect. It
may also be combined with bitters and even with ferruginous tonics in
the advanced stages.
In combination with neutral salts and digitalis, iodide of potassium
would seem to be indicated. Results however do not show a great
superiority to other diuretics in favoring absorption.
Tincture of iodine, painted upon the chest over the affected parts, and
repeated until tender, acts more or less as both a derivative and
deobstruent. A liniment of iodide of potassium and soap is a convenient
form of application.
The inunction of the chest walls with mercurial ointment has strong
advocates both among physicians and veterinarians, and is combined in
such cases with the exhibition of calomel internally. Unless the good
effects are shown in a day or two it may well be abandoned.
When effusion becomes dangerous through excess, and in advanced cases
when it fails to yield to medicinal measures thoracentesis is called
for. (See under _hydrothorax_.)