Phosphaturia

Phosphaturia, the excretion of cloudy, milky-white urine of alkaline reaction, containing large amounts of amorphous salts of alkaline earth metals (calcium and magnesium) and phosphoric acid. Clinically, true, or constitutional P. is distinguished from symptomatic P., which is observed in a number of disorders of acid-base balance in the body. Unlike the second form, primary essential P. is an expression of deep, apparently hereditarily conditioned disorders of mineral metabolism and kidney function. Such P. should therefore be regarded as a special disease, resp. as a separate nosological unit among diseases of metabolism. Secondary, or symptomatic P. can occur in the most diverse pathological conditions and diseases characterized by a decrease in the amount of acid valences or an increase in the amount of bases in the body. The kidneys, as one of the organs regulating the exchange of acids and bases in the body, in such cases promote the restoration of the so-called acid-base balance by the enhanced excretion of excess alkaline ions with urine. As a result, large amounts of di- and tribasic salts of calcium phosphate appear in the urine. Due to their poor solubility, these salts precipitate from the urine in the form of sediment shortly after urination. Such P. can occur, for example, following increased secretion of strongly acidic (rich in H-ions) gastric juice. P. can also develop as a consequence of abundant vomiting of acidic masses with a high content of hydrochloric acid in them. Finally, with a uniform plant-based diet, urine can become amphoteric or even alkaline, which often leads to the precipitation of calcium phosphate salts. A characteristic feature of all the above-mentioned forms of P. is that they occur or rather manifest themselves usually only after the urine is excreted from the body and cools; such forms of P. are not persistent and quite easily cease with the elimination of the primary cause. True, or primary forms of P. are undoubtedly constitutional disorders. Clinically, they manifest in the form of attacks or paroxysms of pain in the kidney area, along the course of the ureters, as well as burning at the end of urination. These attacks can be caused or provoked by various circumstances - these include neuropsychological shocks, gross dietary errors, etc. A characteristic feature of true P. is the precipitation of abundant calcium phosphate sediment still within the urinary tract. The second distinctive and very important sign of primary P. should be considered the formation on the surface of the urine and at the point of its contact with the vessel wall of a thin whitish, greasy, iridescent film, the density of which increases as the phosphate precipitate forms. As for the extrarenal symptology of P., it is not characteristic, but it can be noted that phosphaturics in most cases belong to individuals with a hypersthenic constitution, suffer from heartburn, constipation, indefinite pains in various parts of the abdominal cavity, irritability, and great neuropsychological lability. The pathogenesis of true P. has not been finally clarified. The attempt to consider P. as calciuria, i.e., exclusively as excessive excretion of alkaline earths, cannot be considered correct. It is true that the ratio ^-1 equal in normal conditions to ^-, increases in P. to ~-~ due to an increase in the amount of calcium in the urine, but this alone cannot exhaust the pathogenesis of P. Urine, as is known, belongs to those biological solutions where poorly soluble compounds, such as uric acid and phosphate salts, are contained in a concentration that many times exceeds their limit of solubility in water. Such stability, especially in alkaline urine, is due to the presence in it of protective colloids excreted by the kidneys in small amounts, but sufficient to keep the most difficultly soluble salts (calcium phosphates) in solution. This especially applies to alkaline urine of herbivores, as well as people who eat plant food. By extracting such alkaline transparent urine with ether, one can observe abundant precipitation of phosphates in it (Lichtwitz). One can therefore assume that the alkaline urine contains a protective colloid, which due to its solubility in ether was thus extracted. The characteristic film on the surface of the urine of phosphaturics also forms from coagulated colloid. Lichtwitz is inclined to see in this a pathogenetic factor of P., all the more so that with the addition of acid, both the phosphate precipitate and the film dissolve, after which the urine becomes clear. The basic pathophysiological feature of phosphaturics perhaps boils down to a violation of the function of the renal parenchyma, which secretes a colloid that does not have sufficient stabilizing properties. Some researchers, however, are not inclined to associate the occurrence of P. exclusively with a violation of such kidney function, taking into account the numerous neuropathic symptoms of phosphaturics; these clinicians see the main cause of P. in the lesion of the autonomic nervous system, which regulates the function of most internal organs and intermediate metabolism. It should be emphasized, however, that opponents of Lichtwitz's theory of the genesis of P. have not been able to present factual material in favor of any other interpretation of the mechanism of development of this condition. The treatment of symptomatic P. does not present particular difficulties: such P. can be eliminated, and sometimes disappears on its own when the primary cause that caused it is eliminated; for example, a decrease in gastric hypersecretion (with atropin), cessation of abundant vomiting, or finally a change in diet by adding acid-rich food leads to the disappearance of symptomatic P. Constitutional P., however, is difficult to treat therapeutically. Special difficulties arise when trying to prevent a phosphaturic attack, which usually occurs without any apparent cause. The best therapeutic and at the same time preventive method in primary P. is a diet rich in acid valences (meat, meat products, oatmeal, glucose, eggs, cottage cheese, etc.). However, achieving a shift in the reaction of phosphaturics' urine from alkaline to acidic is only possible with great difficulty, since the kidney of a phosphaturic apparently has a reduced ability to excrete anions. Nevertheless, the injection of atropin, the administration of so-called 'acidic' food often brings significant subjective relief to the patient and reduces or sometimes stops an attack of P. Such a dietary regime, along with general hygienic measures, such as warm baths, abundant drinking, in particular weakly mineralized water (Essentuki No. 20), moderate exercise, neuropsychological rest, creates conditions for the cessation of phosphaturic attacks and subjective pain sensations, without, of course, eliminating the constitutional defect in metabolism leading to P. This is obviously the basis for the observed cases of 'cure' of primary P. In essence, it is only a matter of eliminating the main symptom of the disease. The treatment of constitutional P. with mineral waters at resorts (Essentuki, partly Zheleznovodsk) is poorly justified, since most mineral waters, when taken internally, strongly alkalinize the urine and thus create conditions for intensifying phosphaturia.