DEMANGE ON AZOTURIA.
The importance of the study of urology has of late been more fully realized by Medical practitioners, and M. Demange in his thesis (Thése de Paris, 1878) has undertaken to give a full account of the progress of this branch of medical science, being also fortunate enough to be able to enrich it by several new or very little known observations on azoturia. The latter seem the most interesting part of his thesis; we give them here briefly. The normal quantity of urea which must be contained in the urine in the space of twenty-four hours is from nineteen to fourteen grammes. If more or less is excreted, this is caused either by some local or general affection. Some years ago, Bouchard, in studying the causes of loss of flesh in patients suffering from diabetes insipidus, discovered that a large number among them lost an enormous quantity of urea. Having thoroughly examined their symptoms he thought himself fully justified in describing azoturia as a special disease, having peculiar clinical symptoms. The affection begins with a sensation of ravenous hunger, polydipsia or profuse sweating. The thirst is excessive, and the urine passed is generally in proportion with the quantity of drink swallowed by the patient. Its density is from 1000 to 1002. In order to be able to calculate justly the amount of urea lost in twenty-four hours, all the urine passed in twenty-four hours, all the urine passed in this time must be kept and mixed. In some cases it has reached the amount of eighty-seven grammes, a most enormous quantity, which proves that nutrition is very much impaired. Senator Kien and M. Bouchard have shown that what is called extractive matter is eliminated, corresponding to urea in such cases, and that chlorates and phosphates are ejected in a similar proportion. We must, therefore, not be astonished if the patients present general symptoms which are analogous to those of diabetic patients, with the exception of the visual troubles of the latter. Both the crystalline lens and the retina remain intact, and the sight is only influenced by the anæmic state of the brain, which is caused by the dyscrasia, and which in certain cases produces a torpor of the intellect verging on imbecility. As in cases of diabetes mellitus and albuminuria, sometimes the quantity of urea decreases, and even falls below the normal amount.
In order to be able to make an exact diagnosis, it is necessary to examine carefully, both the urea and the other excreta, for several days consecutively. As a rule, persons attacked by simple polyuria, or who are suffering from interstitial nephritis, beginning with polyuria, do not present the symptoms which we have enumerated.
Disturbances of the nervous symptom and alcoholism claim the first place in the etiology of this affection, and indicate the treatment which has to be adopted. It consists in administering drugs to calm the nervous erethism (opium and valerian), and to put a stop to the excessive and progressive impoverishment of the tissues (arsenic, a suitable diet, etc.) Valerian has proved specially successful in different cases, even effecting a complete cure. Besides these cases of azoturia, combined with polydipsia, Bouchard thought that there was another form of the same disease, in which there was no abnormal excretion of urine, although the latter contained an excessive amount of urea. However, as his observations in that respect are far from being satisfactory, and as these are evidently cases of cachexia, the etiology of which is very obscure, it will be wiser to leave them alone for the present. The author then goes on to consider the much-debated question on the varying amount of urea in glycosuria. In some patients suffering from the latter affection, as much urea is eliminated as the general amount in azoturic patients. It is true, however, that there may be something more than a simple coincidence between these two affections, and several authors have tried to link them together. Lécorché, who admits the hepatic theory of the formation of urea, thinks that this is only the double result of hyper-activity of the functions of the liver. Bouchard, on the contrary, considers it as a true complication of the existing affection, where troubles of nutrition are added to those resulting from insufficient respiratory combustion. According to him, the difference between melitæmia and azotæmia consists in the first resulting from the accumulation of a product of secretion, while the second results from the accumulation of a product of secretion. Azoturia is, therefore, as we said, only a complication, an accessory element which must, however, be considered as being a most important prognostic symptom. According to the same author the abundance of sugar in diabetes is owing more to a want of combustion than an exaggerated production of this substance in the organisms. If this be the case, how can we explain the coincidence of an abnormally low temperature with the production of an exaggerated quantity of urea, such as has been observed in every case without exception? This is the weak point of M. Bouchard’s theory, and it would perhaps be better to refrain from giving a decided opinion on the subject until it has been more thoroughly studied. In short, whenever there is an excessive excretion of urea we may consider it as a symptom of incipient cachexia, followed by loss of flesh. The most important question, however, for the medical practitioner is the following: are these two affections to be considered as belonging to two different groups, but having been developed incidentally at the same time in the same patient; or are they connected through a link which is still unknown to us, thereby forming one affection or disease? If these questions could be solved, there might be some hope of discovering some rational mode of treatment, so as to prevent albuminuria from setting in, in which case all is lost. In another chapter we find the calculation of the amount of urea excreted in several chronic diseases, such as obesity, syphilis and athrepsy. Here it is easy to make a mistake, and still more so to err in trying to interpret the results obtained, because here the nourishment taken by the patient plays an important part, which is easily overlooked, e. g., in fleshy persons. Azoturia may be produced either by excess of food, or by abstaining from farinaceous food. The only way of ascertaining if the combustive functions are really exaggerated in a patient would be to compare the amount of chlorates contained in the secretions with the weight of the patient. Since Brouardel published his paper, on what he termed the uropoietic functions of the liver, several experiments have been made to ascertain the amount of urea excreted in diseases of this organ. The results have been very contradictory, but it is certain that large quantities of urea have been found in the urine of patients whose liver was completely degenerated.—London Medical Record.