Chronic Kidney Disease

Symptoms

Initially, CKD can only be diagnosed by the presence of protein in the urine, more often albumin. At the same time, signs of the underlying disease are observed: high blood pressure, high blood glucose levels, etc.
In the future, the formation of urine (polyuria) increases, its daily volume reaches 2-3 liters. The patient urinates more often, but, unlike the symptom of frequent urination, a lot of urine is separated each time. Nocturia is also noted - two or more nocturnal urges to urinate. At the same time, more urine is excreted at night than during the day.
Polyuria and nocturia, especially in combination with anemia, should alert for possible CKD. It can also be suspected when edema appears on the face, hands or feet, constant thirst, general weakness, poor appetite and high blood pressure. With the progression of the disease, weight decreases, weakness increases and performance deteriorates. At the same time, hypertension becomes uncontrollable, i.e., drugs stop helping.
In the later stages of the disease, urine output is greatly reduced, up to a complete absence at the final stage. Patients become lethargic and lethargic. They often complain of severe weakness, nausea, dryness and unpleasant taste in the mouth, aversion to food, especially meat, yellowness, pallor and grayish skin tone, skin itching, chilliness and cramps in the calf muscles. High blood pressure is replaced by hypotension, joints, bones and spine can hurt, there is a burning sensation and crawling in the legs.
All symptoms of CKD, with the exception of changes in the amount of urine produced, are nonspecific. They occur in diseases that lead to the development of CKD, such as hypertension or diabetes mellitus. Kidney damage in the presence of such symptoms can be suspected when there is pain and discomfort in the lower back, the color of the urine changes - it becomes red, brown, frothy, contains flakes and sediment.
 

Causes

Chronic kidney disease is recognized as a polyetiological disease. Pathology occurs in diseases of the urinary and other organ systems, the presence of modifiable and non-modifiable risk factors in the patient. All of them cause structural damage to the kidneys, which is manifested by a decrease in their function and corresponding clinical symptoms. Main causes of CKD:

•    Diabetes mellitus . Diabetic angiopathy and nephropathy are recognized as the main etiological factor in renal dysfunction. Diabetes is diagnosed in 30-42% of patients with severe forms of CKD who require replacement therapy. The condition can occur in type 1 and type 2 diabetes.

•    Kidney diseases. The leading role is played by chronic glomerulonephritis , which occurs in 35% of people with signs of CKD. No less significant are infectious pathologies ( Pyelonephritis , Cystitis, Urethritis), obstructive diseases of the urinary tract ( Urolithiasis, Tumors, Prostate Adenoma in Men ).

•    Cardiovascular diseases. Arterial hypertension and associated hypertensive nephropathy cause organ fibrosis and are considered a common cause of CKD. The mutual aggravating effect of these diseases on long-term prognosis for patients.

•    Metabolic disorders. Obesity, dyslipidemia, and metabolic syndrome are all risk factors for chronic renal disease. Non-alcoholic fatty liver disease is a risk factor. Long-term ingestion of protein in extremely high amounts (bodybuilder diet) can cause disease.

•    Chronic inflammation. This condition is observed in autoimmune diseases: vasculitis, systemic lupus erythematosus, rheumatoid arthritis . The cause of a persistent inflammatory process is also infection: human papillomavirus, herpesviruses, pathogens of hepatitis b and c.

•    Medicinal toxicity . Chronic kidney disease is caused by long-term use of nephrotoxic drugs. These include some types of antibiotics, cytostatic drugs, non-steroidal anti-inflammatory drugs. Radiopaque agents have a negative effect with frequent use.

Risk factors:
The term CKD includes kidney damage caused by infectious, atherosclerotic, autoimmune and other causes.
Risk factors for the development of chronic kidney disease are divided into modifiable and non-modifiable, that is, those that can and cannot be influenced.
•    Non-modifiable factors include advanced age, hereditary predisposition, congenital low nephron count, such as underweight at birth, previous acute kidney injury, racial and ethnic factors.
•    Modifiable factors include hypertension, diabetes mellitus, tobacco smoking, drug toxicity, chronic inflammation or systemic infections, urinary tract obstruction, pregnancy, and high protein intake.
 

Treatment

Conservative therapy

The main method of CKD correction is nephroprotection. This is a set of measures that is aimed at slowing down the progression of structural changes in the kidneys, maintaining their function at the highest possible level, delaying the development of terminal chronic renal failure. The tactics of treatment is determined by the stage: at c1, the underlying pathology is corrected and observation is carried out, at c2-c4, pharmacotherapy and treatment of complications are required, at c5, substitution therapy is used.

Therapy begins with the elimination of modifiable risk factors: quitting smoking, adding feasible physical activity, reducing the level of salt in the diet. Obese patients are advised to reduce body weight to a medical standard. As CKD progresses, protein intake should be reduced to minimize the burden on the kidneys. 

Medications play a significant role in treatment:

•    Ace inhibitors. The main class of nephroprotectors that reduce proteinuria, slow the progression of renal dysfunction, are used in the treatment of hypertension. According to the indications, angiotensin receptor blockers are used, which have similar effects.

•    Diuretics. Drugs are prescribed to effectively control blood pressure, prevent further damage to the kidneys. Medicines from the group of thiazide and loop diuretics, aldosterone antagonists are used.

•    Lipid-lowering drugs. Drugs correct the manifestations of nephrotic syndrome, prevent cardiovascular crises, and reduce mortality in the group of patients with chronic kidney disease.

•    Iron preparations. Medications are prescribed to correct renal anemia in tablet form or parenterally for malabsorption in the gastrointestinal tract. According to indications, they are supplemented with erythropoietin preparations to stimulate erythropoiesis.

Tests Required for Diagnosis

Patients with signs of renal dysfunction require urgent consultation with a nephrologist or urologist, since clinical manifestations indicate significant damage to the organ. At the initial appointment, complaints and anamnesis are collected, possible predisposing factors are clarified, and a physical examination is performed. The following examination methods are used to make a diagnosis:

•    Kidney ultrasound . Ultrasound diagnostics is used for non-invasive non-radiation visualization of the cortical and medulla of the kidneys, determination of dilatation of the pelvicalyceal system, diagnosis of cysts and other pathological formations. With the help of ultrasound, blood flow in the renal vessels is assessed.

•    Excretory urography . A targeted x-ray examination provides detailed information about the structure of the kidneys and urinary tract, the presence of volumetric neoplasms and other obstructions to the outflow of fluid. According to the results of the study, the activity of the excretory function of the organ is evaluated.

•    CT scan of the kidneys . Highly informative diagnostics, according to which structural changes in the renal parenchyma, neoplasms, signs of nephrolithiasis are determined. The technique is complemented by ct angiography for visualization of the renal vessels. For a more detailed study of the kidney parenchyma, mri may also be prescribed.

•    Nephroscintigraphy . An informative method for diagnosing chronic renal failure (crf), the degree of perfusion and the activity of excretory processes. The technique evaluates the function of each kidney separately and is used for differential diagnosis of various causes of CKD.

•    Lab tests. Urinalysis markers for chronic kidney disease include albuminuria/proteinuria, changes in cell sediment (erythrocyturia, leukocyturia , cylindruria). In the blood, azotemia, disturbances in the balance of electrolytes and acid-base balance are determined. The most important parameter is gfr, which is calculated from creatinine clearance.

 

Useful info

Regardless of the cause, CKD follows a similar mechanism: it is characterized by glomerulosclerosis, fibrosis of the tubular apparatus and interstitial space. Glomerular sclerosis begins with immune, hemodynamic, or metabolic damage to the endothelium, which triggers the classic inflammatory process. This is followed by infiltration by inflammatory cells, active selection of cytokines, and apoptosis of glomerular cells.
The prolonged existence of the pathological process leads to active proliferation, increased synthesis and deposition of extracellular matrix components. The glomeruli are gradually sclerosed, the number of functioning nephrons decreases, so the load on them increases. Hyperperfusion of the remaining healthy cells causes their damage, as a result of which the disease progresses steadily, the rate of urine filtration is constantly reduced.

 Classification and stages of development of CKD:
When systematizing the disease in practical nephrology, the clinical recommendations of the initiative group kidney disease: improving global outcomes are used. The paper presents the definition, diagnostic criteria and prognosis in CKD. According to these recommendations, there is a classification of chronic kidney disease by stages, which takes into account the indicators of glomerular filtration rate (gfr):

•    C1 - kidney damage is already present, but does not significantly affect the functional state of the organ, so the level of gfr is more than 90 ml / min / 1.73 m2.

•    C2 - initial violations of compensatory processes, as a result of which gfr slightly decreases to the level of 60-89.

•    C3 (a and b) - progressive damage to the renal tissue and the corresponding inhibition of the urinary function, as evidenced by the gfr in the range of 30-59.

•    C4 - a sharp depression of renal function (gfr 15-29), which is accompanied by vivid clinical symptoms and a significant decrease in the patient's performance.

•    C5 - the final stage of the disease, in which gfr decreases to less than 15, to maintain life, patients require constant replacement therapy (dialysis).