Kidney stone disease

Renal stone disease is associated with the formation of calculi in the kidneys, or rather in cups and pelvis, which causes a variety of pathological changes in the kidneys and urinary tract.

Etiology, pathogenesis. The causes of kidney stones have not been studied enough. A certain role is played by metabolic disturbances: phosphoric-calcium, oxalic acid, uric acid and, more rarely, amino acids. Important factors in the formation of urinary stones are infections and disorders of the urodynamic function of the kidneys and urinary tract. Disorders of phosphorus-calcium metabolism are due to hyperparathyroidism, certain endocrinopathies, bone injuries, hypervitaminosis D, long-term intake of alkalis and calcium salts, ie, excess renal calcium and phosphate. Calcium phosphate stones are formed at a urine pH of about 7.0. The increased isolation of oxalic acid salts and the formation of calcium oxalate stones are due to excessive endogenous formation of oxalates and excessive intake of oxalic acid or oxalate-forming substances as a result of metabolism (for example, taking large doses of ascorbic acid). Oxalates precipitate at a urine pH of about 5.5 and an increase in the concentration of calcium ions. The solubility of oxalates is enhanced in the presence of magnesium ions in the urine.

Uraturia and urate formation are observed in the violation of the exchange of uric acid (gout), with diseases accompanied by the breakdown of its own proteins, and with excessive intake of food from purine bases. Urate stones are formed at a urine pH below 5.5, and at pH above 6.2 they dissolve. Rarely formed stones from cystine in cystinuria and stones of a different chemical composition. Often urinary stones have a mixed composition. For the formation of concrements, certain conditions are necessary - urinary infection and urinary stasis. Kidney stones cause not only inflammation of the mucous membrane of the pelvis and calyces, but also secondary interstitial nephritis. Infection and obstruction of the urinary tract aggravate pathological changes (apostematous nephritis, calculous pialonephritis, etc.) and disrupt kidney function.

Symptoms, course. Sometimes the disease occurs secretly and is detected accidentally during X-ray examination on another occasion, or its first signs appear when the stone is large, and the patient only notes dull indeterminate pain in the lumbar region. Most often, with a small stone, the disease is manifested by attacks of renal colic, and in the period between attacks-blunt pain, changes in urine, the removal of stones and sand. Dull pain in the lumbar region increases with prolonged walking, during a shaking ride, after lifting weights, but more often without certain reasons. Since the patient often uses a heating pad (after which the pain subsides), you can see the "marble" skin pigmentation in the area above the affected kidney. Repeated urine tests in kidney stones always reveal a microhematuria that intensifies after walking and physical exertion.

Piuria is a common symptom of a disease that, along with bacteriuria, indicates infection of the stone. Increased body temperature and leukocytosis often accompany renal colic and are not always due to a purulent infection. But long-term, non-stop pain in the lumbar region, accompanied by fever and leukocytosis, can be a manifestation of developing apostematous nephritis and serve as an indication for hospitalization of the patient. Purulent infection often complicates the course of nephrolithiasis and leads to the occurrence of calculous pyelonephritis (or pionephrosis). When urine outflow is disturbed, these complications are accompanied by an increase in body temperature, symptoms of intoxication, leukocytosis, a shift of the leukocyte formula to the left, an increase in ESR. Another formidable complication is anuria. It can be the result of obturation of the urinary tract on both sides (or a single kidney), but often anuria develops as a result of bacterial shock when one ureter is obturated.

Diagnosis. Kidney stone disease is easily diagnosed if, after renal colic, hematuria appears and urinary stones leave. In the absence of these signs, the diagnosis is made on the basis of the combination of the above symptoms and the data of the urological examination. X-ray examination is the main method of diagnosis of nephrolithiasis. The most valuable intravenous urography, it allows you to determine the presence of stones, their number, location, size, condition of the kidneys and urinary tract. The detection of a stone that does not retain X-rays is very likely to indicate that it is an urate.

Treatment of nephrolithiasis is aimed at arresting attacks of renal colic, removal of stone, treatment of infection and prevention of recurrent stone formation. Solving these problems requires special knowledge and consultation of a urologist. Only a smooth stone with a diameter of less than 10 mm can independently move away. Surgical removal of kidney stones is indicated with concomitant infection, obstruction of the urinary tract, impaired renal function, and painful repetitive pain. Conservative treatment and prevention of recurrent stone formation depend on the composition of the stones. Elimination of infection and urine acidification are the main measures to prevent recurrence of phosphate formation. The diet should be rich in proteins, contain animal fats. You can prescribe ascorbic acid 3-4 g / day or methionine 3-4 g / day. Prevention of oxalate formation is to observe a diet that excludes foods rich in oxalic acid, ascorbic acid, calcium salts (sorrel, beans, chocolate, milk, etc.). With phosphaturia and oxalaturia, it is advisable to use magnesium preparations (magnesium oxide, 0.15 g 3 times a day), and after surgery - methylene blue. Urate stones can be dissolved using a diet and alkalinizing urine, and drugs that reduce the formation of uric acid. Diet with urates excludes foods rich in purine compounds (poultry, kidneys, liver, cheese, coffee). Food should be predominantly plant. To alkalize urine, magurlite, sopuran, blemarene and other similar preparations are used in doses that ensure the maintenance of urine pH between 6.2 and 6.6. Allopurinol - a drug that reduces the formation of uric acid, is used for a high concentration of uric acid in the blood. In the prevention of any stone formation, it is important that urine is not highly concentrated. The patient should drink a lot of fluids, spa treatment is indicated (Truskavets, Sair-me, Zheleznovodsk, etc.).

The prognosis with timely and adequate treatment is favorable.