urine are afforded by cases of diabetes mellitus and diabetes
insipidus. But a daily excretion of from 70 to 100 ounces is common
enough with atrophied kidneys, with large white kidneys, and with waxy
kidneys.
It is exceedingly difficult to form any rational idea of the causes of
the variations in the amount of urine in the course of the same case,
and in different cases with similar kidney lesions. Various
explanations have been attempted, ascribing these changes to the
hypertrophy of the left ventricle of the heart, to changes in
blood-pressure, to lesions of the arteries, to changes in the
composition of the blood, to lesions in particular portions of the
kidneys. But any one who tries to apply these explanations to any
number of actual cases will find many difficulties.
The most evident causes of diminution in the amount of urine seem to be
an abnormal condition of the circulation of the blood and either
congestion or structural changes of the kidneys.
The specific gravity of the urine varies from day to day and from hour
to hour in the same person, having a regular relation to the quantity
of urine passed. But a long-continued deviation from the normal
specific gravity is usually an evidence of disease. The highest
specific gravities obtain with saccharine diabetes. Abnormally high
specific gravities also often occur in the urine of patients with a
high temperature, with chronic congestion of the kidneys, and in some
cases of acute and chronic parenchymatous nephritis.
Low specific gravities are the rule in diabetes insipidus and with
acute and chronic diffuse nephritis. In chronic diffuse nephritis the
specific gravity remains low even if the quantity of urine passed is
very small. When there is almost suppression of urine from occlusion of
the ureters the urine that is passed is of low specific gravity.
These changes in specific gravity correspond of course to the amount of
solid matter in solution in the urine, and may depend upon a change in
the relative proportion of the fluid and solid constituents of the
urine, or upon an absolute increase or decrease of the solid portions.
Any change in the absolute amount of solid matter excreted in the urine
must depend upon changes in the composition of the blood, or in the
circulation of the blood through the kidneys, or in the structure of
the kidneys themselves. All these three conditions seem to exist in
Bright's disease, and either together or separately may diminish the
daily excretion of solid matter.
It is not necessary here to enumerate the different solid constituents
of {75} the urine. A change in the amount of many of them merely
indicates disorders of the digestive process. Urea seems to be the most
important of the excretory substances, and its quantity is regularly
diminished both in acute and chronic Bright's disease.
Blood is found in the urine in a considerable number of cases of
Bright's disease. If it is present in large quantities, the urine will
be of a reddish color; if in smaller quantities, of a smoky color; and
if in still smaller quantities, the color will not be changed. Blood is
found regularly with acute diffuse nephritis, with the more severe
cases of acute parenchymatous nephritis, with the exacerbations of
chronic diffuse nephritis, and with suppurative nephritis. The blood
seems to be derived from the tufts of vessels in the Malpighian bodies.
Albumen in the urine is a very common symptom of renal disease, but it
is not confined to such cases. It is also found without any structural
lesions of the kidneys.
1. There are some individuals whose urine, for many years, will contain
small quantities of albumen, and yet their general health is good and
they never develop any renal symptoms. In some of these cases the urine
is always somewhat diminished in quantity, and in some there is also a
little sugar in the urine.
2. In a large number of perfectly healthy persons small amounts of
albumen will appear as a temporary condition after muscular exercise,
sea-bathing, eating certain kinds of food, etc.
3. Albumen may be present in considerable amount for weeks or months in
the urine of young persons, and then disappear altogether. The general
health may continue good or be somewhat depreciated. After a time the
albumen disappears and the patients have no further trouble.
4. General convulsions, concussion of the brain, and transfusion of
blood often produce a temporary albuminuria.
Some observers believe that albumen is always present in the urine, but
in such small amounts as to elude the ordinary tests.
Both physiological and pathological albuminuria is most constant and
abundant after eating.
The albumen is not all of the same character. Most of it is
serum-albumen, but with it is a smaller amount of globulin and
sometimes of peptones. As yet the serum-albumen seems to be of the
principal practical importance.
Pathological albuminuria is most constant and the albumen is most
abundant with acute and chronic parenchymatous nephritis, with acute
diffuse nephritis, and with the large white variety of chronic diffuse
nephritis. It is least constant and least abundant with the atrophic
variety of chronic diffuse nephritis, with some waxy kidneys, with
interstitial nephritis, and with chronic congestion of the kidney. A
variety of explanations have been given to account for the production
of albumen by diseased kidneys, but none of them are very satisfactory.
The albuminuria has been ascribed to disease of the epithelium of the
Malpighian bodies; to increase of the blood-pressure within the renal
arteries, either with or without disease of the arterial walls; to
slowing of the blood-current in the arteries; to diminution of the
blood-pressure in the arteries; to congestion of the renal veins; to
changes in the {76} composition of the blood; to changes in the
epithelium of the renal tubules.
For practical purposes it is to be remembered that large amounts of
albumen regularly indicate structural changes in the kidneys; that
small amounts of albumen are found without any kidney lesions, with
chronic congestion of the kidney, and with chronic diffuse nephritis;
that chronic diffuse nephritis may exist without albuminuria for a long
time.
In many cases of kidney disease we find in the urine bodies of
cylindrical shape called casts. The same bodies are also found within
the tubules of diseased kidneys. Concerning the nature and origin of
these bodies we are still ignorant. We only know that they are formed
within the kidney tubules and are carried thence into the urine. With
the exception of the blood-casts, which are composed simply of a number
of blood-globules pressed together, all casts seem to be formed of a
peculiar homogeneous hyaline substance to which other elements may be
added. Hyaline casts are composed entirely of such material. Waxy casts
are formed of the same substance, which becomes denser. Epithelial
casts are made by the adhesion of epithelial cells to the surface of
hyaline casts. Nucleated, granular, and fatty casts are hyaline casts
with the fragments of degenerated epithelium incorporated in them.
Occasionally hyaline casts are found in the urine of healthy persons.
They also occur as a temporary condition after severe muscular
exertion, with typhlitis, with renal calculi, and with jaundice. Most
frequently, however, they are associated with structural disease of the
kidneys. Usually they are found in albuminous urine, and in proportion
to the amount of albumen, but we may find casts without albumen and
albumen without casts.
With chronic congestion of the kidney the casts are hyaline and few in
number. With acute parenchymatous nephritis there are hyaline,
granular, nucleated, and epithelial casts. With chronic parenchymatous
nephritis there are hyaline, granular, and nucleated casts. With acute
diffuse nephritis there are blood, epithelial, hyaline, granular,
nucleated, and fatty casts. With chronic diffuse nephritis there are
hyaline, waxy, granular, fatty, nucleated, and epithelial casts.
An accumulation of serum in the subcutaneous connective tissue, in the
serous cavities, and in the lungs is one of the regular symptoms of
Bright's disease. It usually appears first in the feet or in the face.
Such dropsy is said to be due to a low specific gravity of the
blood-serum; to the loss of albumen; to the scanty elimination of
urine; to hydræmia plethora; or to changes in the walls of the
blood-vessels.
The functions of the stomach are often disordered, either with or
without the existence of chronic gastritis. Loss of appetite, nausea
and vomiting, oppression after eating, etc. continue and grow worse
throughout the disease. Vomiting is also a frequent concomitant of the
so-called uræmic attacks.
Diarrhoea often occurs with dropsy and a scanty excretion of urine, and
may then be of service to the patient, but it sometimes becomes very
profuse, rebellious to treatment, and is of positive injury.
Dyspnoea associated with Bright's disease seems to occur in several
different ways. It may be of mechanical origin from oedema of the lungs
or from hydrothorax. It may be a purely nervous phenomenon, {77} or it
may depend upon a complicating heart lesion. The nervous dyspnoea seems
to be allied to the uræmic vomiting and cerebral symptoms; it is often
most distressing.
In the course of chronic Bright's disease disturbances of vision occur
dependent on three different conditions: (1) There may be a loss of
vision, usually temporary, without any discoverable lesion of the eye.
(2) There may be simple neuro-retinitis. (3) There may be the
characteristic nephritic retinitis with hemorrhages and fatty
degeneration of the retina. These two forms of retinitis are often the
first symptoms of renal disease.
Neuralgic pains, most frequently referred to some part of the head or
face, but also to other parts of the body, are prominent symptoms in
some cases.
The Blood.--Both in acute and chronic Bright's disease the patients
often become markedly anæmic and pale. This change in the color of the
patient corresponds to an alteration of the composition of the blood
with the details of which we are not as yet fully acquainted. The blood
seems to be thinner and more watery.
Cerebral Symptoms.--Headache, drowsiness, stupor, sleeplessness,
delirium, coma, muscular twitchings, and general convulsions are of
frequent occurrence. The headache and drowsiness may continue during
the course of the disease for many months. The stupor, sleeplessness,
delirium, coma, muscular twitchings, and general convulsions are apt to
occur in attacks which last for several days, and then pass away or
terminate in the death of the patient. With such cerebral symptoms are
often associated dyspnoea, vomiting, increased temperature, and
diminution in the excretion of urine. The entire group of symptoms is
commonly known by the name of uræmia.
It is a matter of great practical importance to determine the cause of
these cerebral symptoms, for otherwise there can be no rational
treatment of them. It is evident that such cerebral symptoms must
depend upon anatomical changes in the brain or its membranes, or upon a
change in the composition of the blood which circulates through the
brain, or upon the quantity of blood supplied to the brain.
It is to be remembered that such cerebral symptoms occur most
frequently with the atrophic form of chronic diffuse nephritis; that
they are often the first symptom of renal disease; that the same person
may have several such attacks, with no cerebral symptoms during the
interval; that the urine is usually, but not always, diminished during
the attack, and becomes more abundant when the attack ceases; that such
attacks also occur with the chronic congestion of the kidney due to
cardiac disease, in pregnant women without kidney disease, and with
diseased arteries and high arterial tension without kidney disease.
Anatomical changes in the brain or its membranes do exist in a
considerable number of cases of chronic Bright's disease. Chronic
meningitis with thickening of the pia mater and an increase of serum is
quite common; anæmia and oedema of the brain-tissue are often seen. But
there are a great many cases with cerebral symptoms without such
lesions, and with such lesions without cerebral symptoms.
The composition of the blood is undoubtedly changed in most of the
cases with cerebral symptoms. It is natural to look for such changes as
{78} are due to perversion of the excretory function of the kidneys,
and to ascribe the cerebral symptoms to the poisoning of the blood by
urea, by urea transformed into carbonate of ammonia, or by the other
excretory matters which should be eliminated by the urine. Moreover, it
has been demonstrated that there is a very marked increase in the
amount of urea contained in the blood in such cases. On the other hand,
we find that suppression of urine with accumulation of urea in the
blood may exist for a long time without cerebral symptoms if the
suppression is due to obstruction of the ureters; that with chronic
congestion of the kidney, puerperal convulsions, and diseased arteries
urea is excreted in fair amount, although cerebral symptoms exist; and
that even in cases of cerebral symptoms with chronic diffuse nephritis
there may be no increase of urea in the blood.
In most of the cases with cerebral symptoms, however, there are other
changes in the composition of the blood, concerning the exact nature of
which we are still ignorant. In most cases of chronic Bright's disease
the patients become pale and the blood is thin and watery; and this is
also often the case with chronic congestion of the kidney and with
diseased arteries. In pregnancy the quantity of blood is said to be
increased: in cholera a considerable part of the fluid portions of the
blood is lost.
Changes in the amount of blood in the brain may be due to lesions of
the cerebral arteries or to contraction of these arteries; to changes
in the arteries in other parts of the body; to organic disease or
functional disorder of the heart; or to a change in the whole amount of
blood contained in the body.
It seems to me probable that the so-called uræmic symptoms are most
frequently due to disturbances of the circulation of blood. Such
disturbances of the circulation produce in the brain cerebral symptoms;
in the lungs, dyspnoea; in the stomach, vomiting; in the kidneys,
suppression of urine.
With the atrophic form of chronic diffuse nephritis we have all the
conditions necessary for an irregular circulation--hypertrophy of the
left ventricle, diseased arteries, and hydræmic plethora. In the other
cases with cerebral symptoms there are also conditions present capable
of interfering with the circulation.
Acute Parenchymatous Nephritis.
PATHOLOGICAL ANATOMY.--The lesions of acute parenchymatous nephritis
vary with the intensity of the inflammatory process.
(1) Mild Cases.--The kidneys are of normal size and weight. The
capsules are not adherent, the surface of the kidney is smooth, the
cortex is of normal color or rather pale. The epithelial cells lining
the convoluted tubes are swollen and granular.
(2) More Severe Cases.--The kidneys are increased in size. The cortex
is thick and whitish, with white striæ extending in to the bases of the
pyramids. The epithelium of both the convoluted and straight tubes and
of the Malpighian bodies is swollen and granular. There is cast matter
in the tubes. {79}
(3) The Most Severe Cases.--The increase in the size of the kidneys is
still more marked. The epithelium of most of the tubes is not only
swollen and granular, but is also in many tubes detached from their
walls. A great deal of cast-matter, and sometimes blood, is found in
the tubes. There are no changes in the stroma or in the blood-vessels
of the kidneys.
ETIOLOGY.--Acute parenchymatous nephritis occurs both as a primary and
secondary lesion. The idiopathic cases occur without assignable cause
or after exposure to cold, and are not very common. The secondary cases
are seen very frequently. They complicate a variety of other diseases.
With pneumonia, typhus fever, and typhoid fever the nephritis is
usually of mild type. With yellow fever and acute atrophy of the liver
the nephritis is very severe. With scarlatina, diphtheria, pyæmia,
peritonitis, phosphorus- and arsenic-poisoning the severity of the
nephritis varies with the different cases.
SYMPTOMS.--(1) The Idiopathic Cases.--The urine is diminished in
quantity and may be suppressed; its specific gravity continues nearly
normal; it contains albumen, usually in large amounts, sometimes blood:
in some cases very few casts are seen, in others there are large
numbers of hyaline, granular, and nucleated casts.
As regards the other symptoms, it is convenient to divide the
idiopathic cases into three classes. In the first class dropsy and
anæmia are the most marked symptoms; with these there are loss of
appetite and a depreciation in the general condition of the patient. In
the second class cerebral symptoms are more prominent. There will be
delirium, convulsions, stupor, coma, and with these persistent
vomiting, dyspnoea, and great prostration, but no dropsy. The third
class suffer from the symptoms of both the other classes. Dropsy,
anæmia, loss of appetite, cerebral symptoms, vomiting, dyspnoea, and
prostration are all present.
(2) The Secondary Cases.--The condition of the urine varies with the
intensity of the nephritis. In the mild cases the urine is unchanged.
In the more severe cases we find the urine diminished in quantity,
containing albumen in varying amount, sometimes blood. Hyaline and
granular casts are often present, but are not very numerous. Dropsy
does not usually occur except with the parenchymatous nephritis of
scarlatina. Nausea and vomiting are not infrequent, but it is often
difficult to tell whether they are due to the primary disease or to the
nephritis. Cerebral symptoms--convulsions, delirium, stupor, and
coma--occur with the more severe cases.
DURATION.--(1) The Primary Cases.--The class of cases characterized by
cerebral symptoms are of short duration. The bad cases die at the end
of a few days, the milder cases recover within a few weeks. The class
of cases characterized by dropsy last longer, often for several months.
(2) The Secondary Cases.--The renal symptoms continue during the course
of the primary disease, and may disappear with the termination of this
disease. But if the nephritis is severe the renal symptoms may continue
for months after the primary disease has run its course. Albumen and
casts are especially apt to persist for a long time. Such a persistence
of the nephritis is especially apt to occur with scarlatina and
diphtheria.
{80} PROGNOSIS.--(1) The Primary Cases.--The cases characterized by
both dropsy and cerebral symptoms usually end fatally. The cases
characterized by cerebral symptoms alone are also very apt to die. The
cases characterized by dropsy and anæmia often get well, but the
albumen and casts may persist for a long time, and the patient may have
several attacks of such a nephritis.
(2) The Secondary Cases.--Here the prognosis varies with the intensity
of the nephritis. The more severe forms of the inflammation may add
very much to the danger of the primary disease or may persist for a
long time afterward.
TREATMENT.--(1) The Primary Cases.--In the cases characterized by
dropsy the first indication is to get rid of the dropsy, and this is to
be done by the methodical use of diuretics, cathartics, and
diaphoretics. It will be found, however, that there is a great
difference in the different cases as regards the precise time when
these remedies will take effect and the dropsy decrease. Usually it is
the best plan during the first few weeks of the disease to keep the
patient confined to bed or to the house, and on a milk diet. From time
to time efforts should be made to reduce the dropsy, but if these
efforts produce no effect they should be discontinued and then tried
again. In addition to the dropsy the condition of the stomach and the
anæmia require treatment. For the stomach the milk diet is perhaps the
most efficacious treatment. For the anæmia iron given by the mouth,
combined with daily inhalations of oxygen gas, is of very great
service. It is very important in these cases to guard against relapses.
If possible, the patients should not return to their ordinary pursuits
for a year after their apparent recovery, but should spend that time in
travelling and improving their health in every possible way.
In the cases characterized by cerebral symptoms it must be confessed
that treatment is not very efficacious. Diuretics have no effect,
cathartics seem to do no good. Systematic sweating, the use of
pilocarpine in small doses twice a day, inhalations of nitrite of amyl,
the administration of chloral hydrate, caffeine, digitalis, and
convallaria, and the use of fluid food in small doses, are indicated.
(2) The Secondary Cases.--While the primary disease, to which the
nephritis is secondary, is running its course there is little to be
done for renal symptoms. If, however, these symptoms persist after the
termination of the primary disease, then the main indication is to
improve the general health in every possible way.
Chronic Parenchymatous Nephritis.
A good deal of confusion is connected with this name, for the reason
that many authors include in this one class all the large white kidneys
except the waxy ones, and such kidneys present a variety of lesions.
There are, however, a moderate number of cases in which the morbid
changes are confined to the epithelium of the tubes and to the
Malpighian bodies. All the kidneys, no matter what their gross
appearance may be, which present changes in the stroma and
blood-vessels, as well as in the tubes, belong properly to the class of
chronic diffuse nephritis. I confine the name of chronic parenchymatous
nephritis, therefore, to {81} those kidneys in which the inflammatory
process runs a chronic course and is confined to the epithelium of the
tubes and the Malpighian bodies.
LESIONS.--The kidneys are regularly increased in size, often weighing
sixteen or twenty ounces. The capsules are not adherent, the surface of
the kidney is smooth. The cortex of the kidney is thick and white, with
white striæ running into the bases of the pyramids; the pyramids are
large and red. The epithelium of most of the tubes and of the
Malpighian capsules is swollen, granular, and detached. Cast-matter is
present in the tubes. There may be an increase in the number of the
small cells which cover the tufts of vessels in the Malpighian bodies.
ETIOLOGY.--This form of nephritis is not very common. It may follow
acute parenchymatous nephritis and chronic congestion of the kidney; it
is one of the complications of chronic pulmonary phthisis, and it
occurs as an idiopathic disease.
SYMPTOMS.--There is a good deal of variety in the different cases as to
the quantity and specific gravity of the urine. Usually the quantity is
somewhat diminished, and the specific gravity is between 1020 and 1030.
Albumen is regularly present in considerable quantity, but it may be
scanty, and may even disappear altogether for a time. Hyaline and
granular casts are usually present, but in small numbers.
Dropsy is a regular symptom, and often goes on to general anasarca,
although the degree of the oedema varies from week to week.
Occasionally a case will run its course without any dropsy.
The functions of the stomach are disturbed, and the patients suffer
from loss of appetite, nausea, and vomiting.
Muscular twitchings, convulsions, stupor, and coma only occur in the
very severe cases.
Dyspnoea is often produced by the dropsy, sometimes is simply a nervous
phenomenon.
Bronchitis with cough and expectoration may be a complication.