Definition:—A general toxemia manifested by a group of symptoms, direct or reflex, referable in the main to the nervous system, which are due to the retention in the body, from deficient or imperfect renal action of certain secretory or excretory products of the kidneys.
Etiology:—Various theories have been advanced concerning the origin of the toxins which cause the disease. Some of these have been sustained for a time, others have been proven to be untenable, while others are accepted because nothing better is suggested. Whether the retained toxins which induce this condition are the identical substances which should be excreted by the kidneys, or whether they are products due to imperfect or irregular tissue metabolism, is one of the yet unsolved pathologic problems. The consensus of opinion is in favor of the latter belief. Whether the morphologic products which should be excreted are toxic in themselves if retained, or whether these substances are changed chemically when retained, producing other substances which are toxic, is a part of the question that demands solution. The condition occurs most frequently in conjunction with and as a result of some one of the forms of acute or chronic nephritis. It occurs also with diseases which, in their course seriously influence the renal organs, or their functions, such as scarlet fever, diphtheria, typhus and typhoid fevers, cholera, yellow fever and gout. It follows profound septic absorption, and occurs during pregnancy.
Urea and uric acid having been found in increased quantities in the blood in uremia, and in decreased quantities in the urine, the theory was accepted for a long time, that these products were the real cause. Frerichs advanced the theory that when urea was retained in the blood, there was a decomposition of its molecule, the nitrogen of which, combining with the carbonic acid and hydrogen, formed an ammoniacal compound, probably the ammonium carbonate. This decomposition would be facilitated or retarded by the condition of the system at the time of the retention. This may explain the fact that an excess of urea may be injected into the blood by way of experiment, in a condition of health, without inducing intoxication.
The author, in 1886 and 1887, made a considerable study of uremic intoxication in horses, in the disease known as azoturia. In this interesting study there seemed to him to be strong grounds for Frerichs' theory, as there is often no disorder, if the animal is kept quiet, until the enormous excess of urea is eliminated. Violent, sudden exercise will develop all the symptoms within a few minutes. It seems reasonable to believe that the exercise produces a toxin from decomposition of the enormous quantity of urea in the blood. It is certain that certain changed conditions must exist in kidney disease, before uremic poisoning occurs, as there are a few cases in which there is no apparent diminution in quantity, either of the solids or of the water. Again, in uremic cases there is usually deficiency of the watery constituent of the urine as well as of the solids, while occasionally there is a very large quantity of water, the specific gravity of the urine being low. Again, to further complicate the solution of the problem, there are several forms of deficient renal action, unaccom panied with uremia.
Symptomatology:—Perhaps the most common form of uremia is that form which is characterized by convulsions. This is designated as the convulsive type. The convulsions may occur without any previous announcement; more commonly, however, especially in puerperal cases, there is an extreme bursting headache. The convulsion is epileptiform in character, involving first, the muscles of the head, face and arms, to be soon followed by one involving a larger portion of the muscular structure of the body, and quickly becoming general. The pulse becomes rapid and usually feeble; there is at first an increase of the temperature, and in occasional cases, the temperature remains high; in others it falls to normal or below. The mind becomes involved, the patient soon becoming unconscious and coma ultimately follows.
In other cases of this same form, the premonitory symptoms are marked; there is for some days headache, drowsiness, dulness, vertigo and amaurosis, faulty vision, spots before the eyes, or the ability to see only half of an object. There may be no apparent alteration of the retina, or there may be congestion or edema, or rupture of a capillary on the retina, or distinct albuminuric retinitis may be present. There may be ringing in the ears and some nausea, with muscular twitchings which increase until the characteristic convulsion appears. This condition is more apt to be present where the uremia is the sequel of some acute disorder. In yet other cases, there are as the first symptoms, dulness, quickly passing into coma, or dulness followed by delirium; occasionally with the delirium there is a mild form of mania or delusional insanity, preceding the convulsions and coma. Often the convulsions are followed by paralysis, which may be general or there may be a hemiplegia, or a local paralysis.
There is a form of uremic intoxication in which the first symptom is difficulty of breathing. The respiration at first is slightly asthmatic, later this difficulty of breathing increases suddenly with exertion; the patient feels suffocated, and is obliged to assume a sitting posture; the skin of the face becomes dusky, but seldom cyanosed. These symptoms may all disappear, leaving the patient apparently well, to recur again with more or less abruptness after a few days, or they may occur only in the night. As the difficulty progresses the respiration may assume the Chayne-Stokes type, which predicts a serious result.
Another manifestation of uremia is that which involves the gastrointestinal tract. This is usually ushered in with vomiting, which is violent and persistent, and which can not be traced to any disorder of the stomach, and is not relieved by treatment directed to this organ. Sometimes this is accompanied with constant nausea of an extreme type. It is not uncommon for a severe diarrhea to occur shortly following the vomiting, which may soon amount to a profuse watery purging.
With all manifestations of uremia, the heart is early influenced. Palpitation with irregular action is common, usually the heart beats slowly and is oppressed at first with a large, round, full, soft stroke. Later it becomes rapid and hard, and still later, in the serious stage of the disease, it becomes very rapid, feeble, soft and easily compressible.
A symptom of uremia which is well-nigh pathognomic and should not be overlooked is the urinous odor of the breath. It differs somewhat from the characteristic odor of urine, but is sufficiently similar to be easily recognized. Occasionally the odor is ammoniacal like that of decomposed urine. The urine is quite scanty, often completely suppressed. When examined it is of dark color, has a high specific gravity, is sometimes cloudy, occasionally loaded with urates, but is usually deficient in urea and is sometimes wine colored from the presence of blood. It usually contains a large quantity of albumin and tube casts.
Diagnosis:—The presence of a scanty quantity of urine which contains albumin, associated with any of the above symptoms, will act as a strong clue to the observing physician. The usual, somewhat erratic symptoms, occurring without unconsciousness, or paralysis, will exclude apoplexy. If hemiplegia, or monoplegia are present, this differentiation will be difficult or impossible. In apoplexy the pupils are unequally dilated and albuminuria is absent at first; in alcoholism, and in opium poisoning, there is an absence of nerve irritation, and of convulsive tendencies. With opium the pupil is contracted, and there is the characteristic odor of the drug on the breath. The increased arterial tension, extreme headache, usually flushed face when convulsions appear, persistent vomiting, the urinous odor of the breath, and accentuation of the second heart sound, are confirmatory before the spasm, causing the spasm to be anticipated where it is not the initial symptom. In coup de soleil, or heat stroke, a differential diagnosis is determined by the existing conditions; the high temperature, more pronounced cyanosis and early absence of albuminuria.
Prognosis:—This condition must be invariably regarded as serious. The prognosis is grave but must be based upon the cause and attendant conditions. While many die a large percentage of the cases respond satisfactorily to treatment.
Treatment.—Elimination is the essential primary consideration in the treatment, whatever the cause of the disease, or whatever the other pathological conditions involved in it. I put my patients immediately to bed and avoid everything of an irritating or exciting nature. If consistent the patient may first have a hot bath, but this is not always admissible. Heat is then applied over the kidneys and this is persisted in until these organs are secreting freely. I consider this the most important of all auxiliary measures. I have had success in almost hopeless cases where I permitted no abatement of bearable heat for from three to five days. A hydragogue cathartic may be early administered and in sthenic cases a full dose of pilocarpin, especially if the secretory functions have been sluggish. The bowels should be kept freely open for several days. Perspiration should be encouraged by the use of jaborandi or of ginger, eupatorium or asclepias, in hot infusion. This result may be attained by a warm wet sheet pack which can be applied every day for several days if the uremic symptoms persist. This is especially valuable in post-scarlatinal, or post-diphtheritic nephritis. If the patient has a high temperature the sheet may be applied at a little less than the normal body temperature, 90° or 95° F. and that enveloped in a dry, warm blanket. The reaction should be complete in a short time. The hot pack is the safest with children and feeble adults, especially those where an eruption has failed to appear satisfactorily, or has receded.
For the convulsions veratrum is the most available remedy. It may be given in from ten to twenty minim doses hypodermically, and repeated in twenty or thirty minutes. The inhalation of chloroform may be needed; occasionally a full hypodermic of morphin is advised, but this remedy is rapidly losing its popularity. Gelsemium will prevent convulsions if they can be anticipated. Five minim doses may be given every hour until its physiological influence is apparent. It acts favorably also upon the kidneys, relieving the extreme irritation often present, producing dilatation of the capillaries, and increasing the functional renal activity. The dose may be given in an ounce of hot water. Later gelsemium may be given in smaller doses in conjunction with macrotys and hydrangea, to continue the process of renal elimination. The introduction of half a dram of sodium bromid and twenty grains of chloral in two ounces of hot water into the rectum will be of material service in controlling convulsions.
In cases of nephritis following scarlet fever, or where there is intense local renal congestion, I have overcome the congestion, established free renal secretion and reduced dropsical symptoms, by the administration of one grain of santonin, alternated with a minim of belladonna, every hour. This is, indeed, satisfactory treatment and will often succeed when other measures have failed.
Other remedies available in bringing about normal renal activity, after the acute symptoms are past, are chimaphila, ten drops every two hours, when there is urinary irritation; polytrichum juniperum when dropsy results from suppression; apocynum when the dropsy is general and the heart weak; triticum or epigea in hot infusion when it is necessary to greatly increase the excretion of water. When uremic coma threatens, one-eighth of a grain of caffein should be given hypodermically every two or three hours. It assists in the elimination of urea and uric acid, overcomes dulness or drowsiness, greatly encourages the action of the heart, and promotes normal respiration. It is indicated with quebracho in uremic asthma. In the restoration of the heart's action and of the general strength of the patient, hypodermoclysis of the normal salt solution, or this solution injected within the rectum every six hours, will exercise a general beneficial influence. It is a direct kidney stimulant also, of much power and efficiency.
Echinacea should be given in from ten to twenty drop doses every two or three hours, in every case where uremia is suspected. It should be continued during the entire course of the disorder. It is positively curative of the disease and prevents convulsions, and other complications.