Diabetes Insipidus.
Synonyms:—Polyuria; hydruria; diuresis.
Definition:—This is a chronic constitutional disorder, of nervous origin, characterized by the passage of a large quantity of urine of low specific gravity, which contains no abnormal constituents.
Etiology:—This condition is more apt to occur in early adult life, and may be directly traced to shock or to some serious injury, which may have been accompanied with fright, or it may follow a heat stroke, or some other direct injury to the nervous system. The transient polyuria of neurasthenics, of hysterical patients, or that due to sudden anger or grief, should not be confused with diabetes insipidus. Blows upon the head and other direct injuries, or cerebral tumors, are sometimes the cause. A number of instances have been found in which there was no doubt that the disease was hereditarily transmitted. It occurs also in tubercular, epileptic and syphilitic patients and in alcoholics, after prolonged infectious fevers and influenza, and as the result of the development of abdominal tumors. Post-mortem investigation, however, carefully conducted, has revealed no characteristic pathological changes with which to account for its occurrence. The pathological conditions observed in the kidneys are only those which will occur as the result of forced, prolonged over-activity.
Symptomatology:—The patients who suffer from this disorder are seldom in good health when the first symptoms are observed. There will probably have been a profuse flow of urine for some little time before the attention of either the patient or physician is called to it. Or there may have been some other occasion for a urinary analysis, when the low specific gravity of the urine has attracted the attention of the physician and has led to an investigation. It will be observed that there is an inordinate thirst, which is only partially relieved by the drinking of a large quantity of water, until the desire to urinate occurs and a large quantity of urine is passed, with a return of the thirst.
The quantity of water passed varies from one gallon to as much as six or eight gallons within twenty-four hours, in extreme cases. An average patient will pass from one to two gallons. The specific gravity of this urine will vary from 1002 to 1005, but I have examined many specimens from many patients where at some time during the twenty-four hours the urinometer would stand at the water point, 1000. When the normal quantity of solids is passed in the excessive quantity of water, the relationship between the solids and water as shown by the specific gravity would necessarily result in a low registration. When the normal solids are reduced, as was the case in the patients above referred to, there are usually other conditions which must be taken into consideration. This same fact is also true when the normal solids are increased or when, with a large quantity of water, the specific gravity of the urine would run from 1010 to 1015. Usually in these cases the urea is in excess.
A simple rule which I have given my students with which to obtain an approximate knowledge of the amount of solids passed is that the weight of the body be multiplied by the arbitrary number six, and this quotient be taken as the standard of comparison to represent in grains the amount of solids he should pass. Then multiply the last two figures of the specific gravity of the urine by the number of ounces of urine passed. By this rule, then, a patient weighing 150 pounds should pass 900 grains of solids in twenty-four hours. If, however, he is passing a gallon and a half of urine with a specific gravity of 1005, he will be passing 192 ounces of urine, which, multiplied by the last figure of the specific gravity, will represent 960 grains, or an approximately correct amount. This rule applies to all cases in uranalysis, and is often of great service for immediate use.
These patients are morose, peevish, irritable, and often despondent. There is dryness of the mouth and of the skin, as all other excretions are deficient. Usually the temperature is subnormal, the pulse large, round, full and slow. The appetite is not often impaired, but from imperfect salivation there is usually impairment of digestion. The loss of flesh is by no means as great as in some cases of diabetes mellitus. The patient is indisposed to exertion, as weariness, exhaustion, muscular aching and transient pains, especially in the loins, are apt to occur from prolonged effort. These patients exhibit a marvelous tolerance to the influence of alcohol, some being able to take enormous quantities without intoxication.
Diagnosis:—The diagnosis depends upon the fact that a patient in fairly good health is subject to constant thirst, passes at frequent intervals a large quantity of pale, limpid urine of low specific gravity, which contains neither albumin nor sugar. It is distinguished from a transient, inoffensive polyuria by its persistency, and from diabetes mellitus by the dark color and high specific gravity of the urine of the latter disease.
Prognosis:—The course of this disease is usually a long one, and during this time there may be no serious impairment of the health. When it arises from causes which in themselves are progressive, or when complications arise, the course of the disease may be more rapid, or death may occur from the complications. A fatal result seldom occurs directly from this malady. Recovery may be promised in a fair proportion of cases.
Treatment:—In the treatment of these patients, the central nervous system must have first consideration. Nerve tonics, easily appropriated restoratives and upbuilding remedies will lay a foundation for the action of specifically indicated remedies. Phosphorus and strychnin will usually be selected as the primary essential remedies. Benefit will be derived from the compound syrup of the phosphates, persistently administered. Where nervous hyperesthesia or nervous irritability exists, a combination of hydrobromic acid and ergot in the proportion of eight or ten minims of the first remedy, in the officially dilute form, and from ten to fifteen minims of the latter remedy, every three or four hours, may be administered. There will be found frequent cases in which this combination may be used as a routine treatment for the polyuria. Ergot is sometimes given alone in half dram doses four or five times a day for this purpose. Another remedy of much benefit, especially in cases where the skin is cold and the circulation, both capillary and general, is sluggish, is belladonna. This remedy exercises a rational physiologically direct influence upon the circulation. It may be applied in the form of a plaster or strong liniment over the spinal cord and across the kidneys. It may be given also internally, in small doses frequently repeated. In occasional cases the hypodermic use of atropin, in one-one-hundredth grain doses, two or three times in twenty-four hours, will be of service; but I prefer the regular administration of one or two drops of the tincture of belladonna every three hours. Rhus aromatic, in twenty drop doses every three or four hours, has been advised, but the specific indications for the drug cannot be given. There is probably an occasional case when it will be found of benefit. Some physicians depend upon the use of morphin or codein to produce restfulness and to control the output of urine during the night, that the sleep be not disturbed. I prefer to depend upon the bromids and hyoscyamus.
In the feeding of these patients care must be taken that any large quantity of water taken be drunk before the meals a sufficient time to permit the stomach to be comparatively empty when food is taken. Any fluid taken during the meals should be taken in sips only, to supply the deficiency of the saliva and to facilitate the thorough mastication of the food.
