How is chronic renal failure treated?

Before starting treatment of a patient with chronic renal failure, it is necessary to determine the disease that led to the development of renal failure, the stage and the main clinical and laboratory symptoms of renal dysfunction. An unambiguous interpretation of these important indicators is considered important for the management tactics, and therefore the use of the same terminological and diagnostic approaches.

Patients with chronic renal failure require dietary correction and syndrome treatment.

A high-calorie, low-protein diet is recommended to help prevent protein-energy malnutrition.

Low-protein diet. Protein metabolism products play an important role in immune and non-immune mechanisms of chronic renal failure progression (increased renal plasma flow, leading to hemodynamic disturbances). Following a low-protein diet in the early stages of renal failure helps reduce excess phosphorus concentration and slow down the development of secondary hyperparathyroidism and renal osteodystrophy. However, it is not recommended to sharply reduce the protein content in the diet of children (unlike adults). In children, depending on age, gender and the severity of chronic renal failure, it should be from 0.6 to 1.7 g / kg of body weight per day (70% - animal proteins).

In order to prevent protein-energy malnutrition (PEM), the risk of which is higher in children with chronic renal failure than in adults, and when a number of products are forced to be excluded from the diet, their full replacement with others of equal nutritional and biological value is necessary. The use of ketoanalogues of amino acids is recommended, as well as the inclusion of soy products in the diet.

Hypophosphate diet. Hypophosphate diet should be followed with SCF less than 50 ml/min, while the phosphorus content in the daily diet should not exceed 800-1000 mg. Products rich in phosphates include milk and dairy products, beans, soybeans, beans, peas, lentils, protein products (eggs, lamb, poultry, liver, salmon, sardines, cheeses), bread and cereal products (corn bread, barley, bran, wafers), chocolate, nuts.

Since it is difficult for children to adhere to a hypophosphate diet, starting from the early stages of chronic renal failure, with a daily content of more than 1 g of phosphates in food, substances that bind them are prescribed.

Drug treatment of chronic renal failure

• Conservative treatment of renal failure begins at the early stages of its development and is determined by the severity of the underlying disease and chronic renal failure, the presence of complications from other organs and systems.
• Children with long-term kidney diseases and a decrease in endogenous creatinine clearance below 70 ml/min are subject to outpatient observation by a nephrologist.
• To slightly reduce the content of nitrogenous wastes in the blood serum, enterosorbents can be used that bind creatinine, urea and other toxic products secreted in the gastrointestinal tract. An absolute contraindication to the use of sorbents is an ulcerative process and/or bleeding in the gastrointestinal tract.
• Treatment should include measures to prevent osteodystrophy: regular monitoring of the concentration of Ca ² parathyroid hormone, phosphates, alkaline phosphatase activity starting from the early stages of chronic kidney disease in children (with SCF <60 ml/min), the administration of calcium preparations in combination with active metabolites of vitamin D ₃.
• The main measures for the prevention and treatment of osteodystrophy in patients receiving renal replacement therapy:
  • maintaining normal calcium concentrations in the blood;
  • ensuring adequate calcium content in the dialysis fluid;
  • reducing dietary phosphate intake;
  • use of phosphate binders;
  • administration of active forms of vitamin D3 _metabolites;
  • correction of acidosis;
  • complete purification of water used to prepare hemodialysis solution.
• Prescription of vitamin D preparations before the occurrence of obvious signs of hyperparathyroidism (hypocalcemia, increased parathyroid hormone concentration, alkaline phosphatase activity in the blood), which helps prevent osteodystrophy and ensure satisfactory development of the child. For successful treatment and prevention of renal osteodystrophy, the parathyroid hormone content should be within the normal range of the pre-dialysis stage and be 150-250 pg/ml in children undergoing dialysis.

• The use of ACE inhibitors helps prevent the progression of sclerotic changes in the kidneys due to a decrease in renal hyperperfusion and a decrease in arterial pressure. Therefore, ACE inhibitors in combination with angiotensin receptor antagonists, beta-blockers and slow calcium channel blockers can be attributed to the basic therapy of arterial hypertension. For example, captopril orally at 0.3-0.5 mg/kg in 2-3 doses or enalapril orally at 0.1-0.5 mg/kg once a day for a long time (under the control of arterial pressure).
• Early correction of anemia, allowing to reduce the left ventricular mass index in patients in the pre-dialysis and dialysis stages of chronic renal failure. Treatment with erythropoietin beta is started if the hemoglobin concentration does not exceed 110 g/l during repeated testing. The lack of effect or insufficient response to treatment with erythropoietin beta is usually due to absolute or functional iron deficiency. Its preparations are recommended to be prescribed to all patients with anemia.
• For patients with chronic renal failure in the pre-dialysis and dialysis periods with a hemoglobin content of less than 110 g/l, the following treatment regimen may be prescribed: erythropoietin beta subcutaneously 2-3 times a week at a weekly dose of 50-150 IU/kg under the control of hemoglobin concentration and hematocrit, determined once every 2-4 weeks. If necessary, a single dose is increased once every 4 weeks by 25 U/kg until the optimal hemoglobin concentration is achieved. Then a maintenance dose is prescribed: for children weighing less than 10 kg - 75-150 U/kg (about 100 U/kg); 10-30 kg - 60-150 U/kg (about 75 U/kg); more than 30 kg - 30-100 U/kg (about 33 U/kg). At the same time, iron preparations (trivalent) are prescribed.

The goal of treatment is to increase the hemoglobin concentration by 10-20 g/l per month. If after the start of treatment with erythropoietin beta or after the next increase in the dose the hemoglobin content increases by less than 7 g/l in 2-4 weeks, the dose of the drug is increased by 50%. If the absolute increase in the hemoglobin concentration after the start of treatment exceeds 25 g/l per month or its content exceeds the target, the weekly dose of erythropoietin beta is reduced by 25-50%.

Renal replacement therapy for chronic renal failure

The problem of replacing lost renal functions in children is complex and has not yet been solved worldwide. This is due to the technical complexity of performing a kidney transplant in a small child and creating a long-term functioning vascular access for hemodialysis, as well as the difficulty of drug replacement of lost humoral functions of the kidneys. The decision on renal replacement therapy should be made in a timely manner to prevent irreversible consequences of uremia for the musculoskeletal system, developmental delays in the child and damage to internal organs.

Indications for initiation of renal replacement therapy in children with chronic renal failure:

• SCF less than 10.5 ml/min;
• the occurrence of symptoms of uremia and its complications: pericarditis, nausea, vomiting, edema resistant to treatment, severe acidosis, blood clotting disorders, neuropathy, severe BEN with SCF less than 15-20 ml/min.

The nephrology service should have the ability to use all three methods of renal replacement therapy (peritoneal dialysis, hemodialysis and kidney transplantation), which will allow choosing the optimal method for the patient.

For full hemodialysis, it is necessary to conduct sessions lasting 4-5 hours 3 times a week, subject to careful monitoring of the process, especially in children and patients with unstable hemodynamics.

There are no absolute contraindications to hemodialysis, but there may be cases when a session cannot be performed for technical reasons.

Contraindications to hemodialysis:

• the child's low body weight and the resulting inability to establish vascular access to ensure adequate blood flow;
• cardiovascular failure;
• hemorrhagic syndrome (risk of severe bleeding during heparinization).

In these situations, peritoneal dialysis is indicated. Peritoneal access in children is easy to perform. Complications associated with the catheter are usually not life-threatening. Continuous outpatient peritoneal dialysis is performed at home by parents; the procedure is painless and takes little time. Periodically (once every 2 weeks), blood tests are performed, as well as an examination of the patient in the clinic.

Benefits of peritoneal dialysis:

• fewer restrictions on the selection of sick children compared to hemodialysis (especially regarding the age and body weight of the child);
• patients on peritoneal dialysis have been shown to have better preservation of residual renal function than patients on hemodialysis. This is why peritoneal dialysis is more suitable for patients with significant residual renal function and the possibility of its restoration;
• According to literature data, the best results of kidney transplantation were observed in patients undergoing peritoneal dialysis;
• Peritoneal dialysis provides a higher quality of life: children can live at home, go to school, and lead an active lifestyle.

Peritoneal dialysis is preferred as a starting treatment method, as it helps preserve residual renal function and is more beneficial for the cardiovascular system.

Contraindications to peritoneal dialysis:

• leakage of the abdominal cavity (presence of ileostomy, drains, early stages after laparotomy);
• adhesions and tumor formations in the abdominal cavity, limiting its volume;
• purulent infection of the abdominal wall or peritonitis.

Dialysis in children with chronic renal failure is usually started only for the purpose of subsequent kidney transplantation, since the period of a child's stay on dialysis is limited. It should be remembered that in combination with drug treatment, it does not restore the lost humoral functions of the kidneys. That is why it is desirable that the waiting time for transplantation does not exceed 1-2 years, and with increasing lag in physical development, an increase in symptoms of renal osteodystrophy, it should be significantly less.

Kidney transplantation is the optimal method for correcting the terminal stage of chronic renal failure in a child. There are no absolute contraindications to transplantation in children. Relative, temporary contraindications that require treatment and dialysis include malignant neoplasms and some diseases accompanied by a high risk of relapse in the transplant. The main source of organs for children is adult donors. The size of an adult kidney allows it to be transplanted into a child even at a young age. The threshold indicators for a child, after reaching which a kidney transplant from an adult donor is possible, are considered to be a height of 70 cm and a weight of 7 kg. Both cadaveric and living related donors are used for kidney transplantation. They must be compatible with the recipient by blood type, have a negative cross-lymphocytotoxic test (absence of cytolysis when combining donor lymphocytes and recipient serum). Matching antigens of the major histocompatibility complex (HLA) is desirable.

After a kidney transplant, the child must receive immunosuppressive therapy for the entire period of transplant function, aimed at preventing rejection. The main principle of the immunosuppression regimen is a combination of 2-3 drugs in small doses. Their choice depends on the presence and severity of side effects. Based on these principles, the child is selected an immunosuppression regimen that is not accompanied by significant side effects and does not affect the quality of life.

Evaluation of treatment effectiveness

Effective treatment of chronic renal failure is evidenced by the absence of a progressive increase in the concentration of creatinine and urea nitrogen in the blood, anemia, osteodystrophy and other complications of chronic renal failure, normal development and satisfactory well-being of patients.

Prognosis for chronic renal failure

Each of the methods of renal replacement therapy has a certain survival period, and transplantation is also considered not the final stage of treatment, but only one of the stages. After the loss of transplant function, it is possible to return to peritoneal dialysis or, in case of loss of peritoneal function, to hemodialysis with subsequent re-transplantation. The current level of development of renal replacement therapy allows us to predict several decades of active and fulfilling life. Nevertheless, chronic renal failure is considered a progressive disease and the mortality rate among children receiving dialysis is 30-150 times higher than in the general population. At the present stage, the expected life expectancy for a child who began receiving dialysis before the age of 14 is about 20 years (US data). That is why the diagnostic and therapeutic approach to chronic renal failure should be aimed at primary prevention, early diagnosis and active treatment at all stages.

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