Nephritis is a disease of the kidneys, in which changes occur in the tissues of the organs themselves; these changes may be caused by inflammation of the kidneys and renal passages brought on as results of the retention of certain poisonous substances in the blood, or from the action of specific bacteria. The disease may be acute or chronic in form and develop as a result of prolonged exposure to cold and wet, of tonsillitis, scarlet fever, typhoid fever, and to a less extent of malaria, syphilis, pregnancy, and tuberculosis, as well as from the effects of certain irritating drugs, such as cantharides and turpentine.
Directing the Treatment.—In any case the treatment must be directed toward the relief of the acute symptoms in the beginning and followed up by a general treatment which will tend to strengthen and relieve the overtaxed organs and to increase their power to functionate normally.
Causes and Effects.—In acute nephritis, the chief symptoms are uremia, and edema; the urine is materially diminished in quantity and at times suppressed; it is often found to be rich in albumen and containing hyaline and blood casts, red and white blood cells, and various pigments.
In chronic nephritis, which may be the result of an acute attack, or as a sequel of other diseases already mentioned, there is seen to be a progressive loss of flesh and strength, marked anemia, gastro-intestinal disturbances, increased blood tension and edema, the latter especially in the face on arising in the morning. Uremia may develop at any time.
Limiting the Work of the Kidneys.—In both acute and chronic nephritis, great effort must be put forth to relieve the tax upon the kidneys and to stimulate their functioning power.
In other diseases, in which definite organs are involved, the treatment consists chiefly of resting the affected parts (1) by starvation, (2) by deflecting the work to other organs when it is possible, chiefly by changing the diet until the disturbance is overcome. This is generally effectual in most cases, as has been specially demonstrated in the treatment of gastro-intestinal diseases.
Problems to Be Considered.—But in nephritis, there are other problems to consider, which make it impossible to institute such a treatment as will effect a perfect rest of the renal organs. The kidneys represent the chief source whereby the waste products of the body are eliminated. This waste consists not only of the end-products of the nitrogenous foods ingested, but also the end-products of tissue metabolism, which is the inevitable result of the wear and tear of life. Hence, when the functions of the kidneys are disturbed, these products, often toxic in character, are retained instead of excreted. Thus instead of forming normal constituents of the urine they find their way into the general circulation, exerting a damaging effect upon the tissues, especially of the kidneys with which they are brought into such direct contact.
Substances Difficult of Excretion.—It has been proved that the kidneys in nephritis find it difficult to excrete certain substances, namely, urea, water, salts, and the purin bodies. Many authorities claim that the uremia manifested in acute nephritis is the result of the retention of end-products of the protein metabolism already mentioned and that the edema is due to a like retention of water and salts. The greatly diminished quantity of urine voided during the acute attack would seem to prove this theory. Martin Fisher,[114] however, claims the condition to be due to an acidulation of the tissues with a consequent osmosis of water, and directs his treatment to overcome this condition, not by restricting the quantity of water and salt, as is generally practised, but by injecting a saline solution into the body in large quantities with the effect of increasing the flow of urine by concentrating the salt content of the blood and therefore its osmotic power. The fluids are withdrawn from the tissues, thus adding fluidity to the blood stream, which in turn flushes the kidneys, ridding them of the poisons which interfere with their normal functioning.
Adjusting the Diet.—The uremia and edema must be relieved. Since it is an undisputed fact, in the majority of cases, that good results from the regulating of the diet so as to minimize as far as possible the work of the kidneys, the various diet cures will be included here.
Milk Cure.—Milk, as a rule, forms a basis of most of the nephritic diets chiefly because of its low salt and protein content and on account of its non-toxic end-products.