Definition.—The continued presence of an excess of calcium oxalate in the urine.
Etiology.—Oxalic acid is found in small quantities, a mere trace, in normal urine, and in still larger quantities, transient oxaluria, after eating certain fruits and vegetables; such as apples, pears, tomatoes, rhubarb, asparagus, cauliflower, spinach, beans, sorrel, etc. It is found in hypochondriasis, diabetes mellitus, catarrhal icterus, neurasthenia, gout, tuberculosis, and cancer. It is supposed to be due to disordered metabolism, especially of the fats and carbo-hydrates.
Symptoms.—"The symptoms of oxaluria are those of greatly depressed vitality. The appetite is irregular, and digestion imperfect, with well-marked dyspeptic symptoms. The secretions are deranged, the skin being very susceptible to external impressions, at times dry and harsh, again soft and flabby and covered with an unnatural perspiration; the bowels are usually torpid and sluggish and do not respond well to the action of medicine. The patient is low-spirited and melancholy, the temper is irritable, and there is great restlessness, and constant brooding over his condition. There is frequently a very disagreeable impression of weight and pain in the loins and small of the back; the urine is voided with increased frequency, and with more or less heat and scalding.
"The patient becomes greatly emaciated as the disorder advances, and frequently sinks into a state of confirmed hypochondriasis. If the disease goes thus far, some other part of the system becomes the seat of the disease, as the lungs, liver, bowels, etc., which carries the patient off."'
Diagnosis.—The specific gravity of urine in oxaluria is usually from 1,020 to 1,030, and, as before remarked, in many cases it contains an excess of uric acid and urates, urate of ammonia being deposited on cooling, and sometimes tinted with purpurin.
The deposit of oxalate of lime occurs in the form of white, glistening powder, which, when examined under the microscope, is found to consist of transparent octahedra, with sharply defined edges and angles. The best way of making the examination is to allow a portion of the urine, passed a few hours after a meal, to stand until cool, then decant the major portion, and pour a part of the remainder into a watch-glass, when, on applying heat, the crystals of oxalate will be collected at the bottom.
Oxalic calculi are next in frequency to the uric; they are generally of a dark-brown color, rough and tuberculated, hard, compact, and perfectly laminated. It is insoluble in the alkalies, dissolves slowly in nitric and hydrochloric acid, if previously well broken up, and under the blowpipe expands and effloresces into a white powder. A variety of this species is remarkably smooth, and of small size, and from its shape has been described under the name of "hemp-seed."
Prognosis.—Is generally favorable.
Treatment.—"In the treatment of oxaluria, the most prominent indications are, to improve the general health, and to establish secretion from the other emunctories. As there is a condition of confirmed dyspepsia, this must be managed as heretofore named. I might here remark that I have found the strong infusion of peach-bark given in quantities of two teaspoonfuls every three hours, and also the tincture of collinsonia in half-teaspoonful doses four times a day, very successful remedies in these cases. I frequently order the triple phosphate of quinine, strychnia, and iron (compound tonic mixture) in half-teaspoonful doses two or three times a day. It should be given with water, as much as half a wine-glassful at every dose. The colorless fluid hydrastis fits some cases well, in doses of half a teaspoonful. The hydrastis is a very efficient agent in some of these cases, as is also the ptelea, populus and liriodendron. These remedies should in all cases be associated with the mineral acids, the nitric being recommended by Dr. Prout, but a combination of one part nitric and two or three of hydrochloric, by others.
"If there is a tenderness on pressure over the epigastrium, I would strongly recommend the irritating plaster. To overcome constipation of the bowels where it exists, we may employ the Podophyllin pill, named under the head of uric acid, or the powder of sulphur and phosphate of soda, named in preceding pages. The diet should be regulated with the greatest care, all agents that produce flatulence or acidity of the stomach being discarded, animal and vegetable food being used in about equal proportions. The same means to increase elimination from the skin, as in the case of uric acids, should be employed here, and especially should flannel be worn next to the skin, and warm clothing-, to protect the body against sudden changes in temperature. In many cases, all drinks but water will have to be excluded, and especially should wine, beer, and other stimulants be proscribed: a small portion of brandy being allowed if absolutely necessary."