Chronic renal failure is a gradual extinction of renal functions caused by the death of nephrons due to chronic kidney disease. In the initial stages, it is asymptomatic, followed by disorders of the general condition and urinary excretion, edema, itching of the skin. Gradual deterioration of kidney function leads to disruption of the vital activity of the body, the occurrence of complications from various organs and systems. Diagnostics includes clinical and biochemical analyses, Rehberg and Zimnitsky samples, ultrasound of the kidneys, ultrasound of the renal vessels. Treatment of CRF is based on therapy of the underlying disease, elimination of symptoms and repeated courses of extracorporeal hemocorrection.
ICD 10
N18 Chronic renal failure
Meaning
Chronic renal failure (CRF) is an irreversible violation of the filtration and excretory functions of the kidneys, up to their complete cessation, due to the death of renal tissue. CRF has a progressive course, in the early stages it is manifested by a general malaise. With an increase in CRF, there are pronounced symptoms of intoxication of the body: weakness, loss of appetite, nausea, vomiting, swelling, skin – dry, pale yellow. Diuresis decreases sharply, sometimes to zero. In the later stages, heart failure, pulmonary edema, a tendency to bleeding, encephalopathy, and uremic coma develop. Hemodialysis and kidney transplantation are indicated.
Causes
Chronic renal failure can be the outcome of chronic glomerulonephritis, nephritis in systemic diseases, hereditary nephritis, chronic pyelonephritis, diabetic glomerulosclerosis, kidney amyloidosis, polycystic kidney disease, nephroangiosclerosis and other diseases that affect both kidneys or a single kidney.
Pathogenesis
The pathogenesis is based on the progressive death of nephrons. Initially, renal processes become less effective, then kidney function is impaired. The morphological picture is determined by the underlying disease. Histological examination indicates the death of the parenchyma, which is replaced by connective tissue. The development of CRF is preceded by a period of suffering from chronic kidney disease lasting from 2 to 10 years or more. The course of kidney disease before the onset of CRF can be conditionally divided into a number of stages. The definition of these stages is of practical interest, since it affects the choice of treatment tactics.
Classification
The following stages of chronic renal failure are distinguished:
- Latent. Proceeds without pronounced symptoms. It is usually detected only by the results of in-depth clinical studies. Glomerular filtration is reduced to 50-60 ml/min, periodic proteinuria is noted.
- Compensated. The patient is concerned about increased fatigue, a feeling of dry mouth. An increase in the volume of urine with a decrease in its relative density. Reduction of glomerular filtration to 49-30 ml/min. Increased creatinine and urea levels.
- Intermittent. The severity of clinical symptoms increases. Complications arise due to increasing CRF. The patient’s condition changes in waves. Reduction of glomerular filtration to 29-15 ml/min, acidosis, persistent increase in creatinine levels.
- Terminal. It is characterized by a gradual decrease in diuresis, an increase in edema, gross violations of acid-base and water-salt metabolism. There are phenomena of heart failure, congestive phenomena in the liver and lungs, liver dystrophy, polyserositis.
Symptoms
In the period preceding the development of chronic renal failure, renal processes persist. The level of glomerular filtration and tubular reabsorption is not impaired. Subsequently, glomerular filtration gradually decreases, the kidneys lose the ability to concentrate urine, and renal processes begin to suffer. At this stage, homeostasis has not yet been disrupted. In the future, the number of functioning nephrons continues to decrease, and with a decrease in glomerular filtration to 50-60 ml/ min, the first signs of CRF appear in the patient.
Patients with latent stage of CRF usually do not complain. In some cases, they note an indistinct weakness and a decrease in performance. Patients with chronic kidney disease in the compensated stage are concerned about a decrease in working capacity, increased fatigue, and a periodic feeling of dry mouth. With the intermittent stage of CRF, the symptoms become more pronounced. Weakness increases, patients complain of constant thirst and dry mouth. Appetite is reduced. The skin is pale, dry.
Patients with end-stage CRF lose weight, their skin becomes gray-yellow, flabby. It is characterized by skin itching, decreased muscle tone, tremor of the hands and fingers, small twitching of the muscles. Thirst and dry mouth increases. Patients are apathetic, sleepy, unable to concentrate.
With an increase in intoxication, a characteristic smell of ammonia from the mouth, nausea and vomiting appears. Periods of apathy are replaced by excitement, the patient is inhibited, inadequate. Dystrophy, hypothermia, hoarseness of voice, lack of appetite, aphthous stomatitis are characteristic. The stomach is swollen, frequent vomiting, diarrhea. The chair is dark, fetid. Patients complain of painful skin itching and frequent muscle twitching. Anemia increases, hemorrhagic syndrome and renal osteodystrophy develop. Typical manifestations of end-stage CRF are myocarditis, pericarditis, encephalopathy, pulmonary edema, ascites, gastrointestinal bleeding, uremic coma.
Complications
CRF is characterized by increasing disorders on the part of all organs and systems. Changes in blood include anemia caused by both the suppression of hematopoiesis and the shortening of the life of red blood cells. Coagulation disorders are noted: prolongation of bleeding time, thrombocytopenia, decrease in the amount of prothrombin. Arterial hypertension (more than half of the patients), congestive heart failure, pericarditis, and myocarditis are observed from the heart and lungs. In the later stages, uremic pneumonitis develops.
Neurological changes in the early stages include absent–mindedness and sleep disturbance, in the later stages – lethargy, confusion, in some cases delirium and hallucinations. Peripheral polyneuropathy is detected from the peripheral nervous system. On the part of the gastrointestinal tract in the early stages, there is a deterioration of appetite, dry mouth. Later, belching, nausea, vomiting, stomatitis appear. As a result of irritation of the mucous membrane during the release of metabolic products, enterocolitis and atrophic gastritis develop. Superficial ulcers of the stomach and intestines are formed, often becoming sources of bleeding.
On the part of the musculoskeletal system, CRF is characterized by various forms of osteodystrophy (osteoporosis, osteosclerosis, osteomalacia, fibrotic osteitis). Clinical manifestations of renal osteodystrophy are spontaneous fractures, skeletal deformities, compression of vertebrae, arthritis, pain in bones and muscles. On the part of the immune system, lymphocytopenia develops in CRF. Decreased immunity causes a high incidence of purulent-septic complications.
Diagnostics
If the development of chronic renal failure is suspected, the patient needs to consult a nephrologist and conduct laboratory tests: biochemical analysis of blood and urine, a Rehberg test. The basis for the diagnosis is a decrease in the level of glomerular filtration, an increase in creatinine and urea levels.
During the Zimnitsky test, isohypostenuria is detected. Ultrasound of the kidneys indicates a decrease in the thickness of the parenchyma and a decrease in the size of the kidneys. A decrease in intra-organ and main renal blood flow is detected on the ultrasound of the renal vessels. X-ray contrast urography should be used with caution due to the nephrotoxicity of many contrast agents. The list of other diagnostic procedures is determined by the nature of the pathology that caused the development of CRF.
Treatment
Specialists in the field of modern urology and nephrology have extensive opportunities in the treatment of CRF. Timely treatment aimed at achieving stable remission often significantly slows down the development of pathology and delays the appearance of pronounced clinical symptoms.
Treatment of the underlying disease
When conducting therapy for a patient with an early stage of CRF, special attention is paid to measures to prevent the progression of the underlying disease. Treatment of the underlying disease continues even with impaired renal processes, but during this period the value of symptomatic therapy increases. If necessary, antibacterial and antihypertensive drugs are prescribed. Sanatorium-resort treatment is shown.
It is required to monitor the level of glomerular filtration, concentration function of the kidneys, renal blood flow, urea and creatinine levels. In case of violations of homeostasis, correction of acid-base composition, azotemia and water-salt balance of the blood is carried out. Symptomatic treatment consists in the treatment of anemic, hemorrhagic and hypertensive syndromes, maintaining normal cardiac activity.
Diet
Patients with chronic renal insufficiency are prescribed a high-calorie (approximately 3,000 calories) low-protein diet, including essential amino acids. It is necessary to reduce the amount of salt (up to 2-3 g / day), and with the development of severe hypertension, transfer the patient to a salt–free diet. The protein content in the diet depends on the degree of renal dysfunction, with glomerular filtration below 50 ml / min, the amount of protein decreases to 30-40 g / day, with a decrease below 20 ml / min – to 20-24 g / day.
Symptomatic therapy
With the development of renal osteodystrophy, vitamin D and calcium gluconate are prescribed. It should be remembered about the danger of calcification of internal organs caused by large doses of vitamin D in hyperphosphatemia. To eliminate hyperphosphatemia, sorbitol + aluminum hydroxide is prescribed. During therapy, the level of phosphorus and calcium in the blood is monitored. Correction of the acid-base composition is carried out with a 5% solution of sodium bicarbonate intravenously. With oliguria, furosemide is prescribed in a dosage that provides polyuria to increase the volume of urine excreted. To normalize blood pressure, standard antihypertensive drugs are used in combination with furosemide.
With anemia, iron preparations, androgens and folic acid are prescribed, with a decrease in hematocrit to 25%, fractional transfusions of erythrocyte mass are carried out. The dosage of chemotherapeutic drugs and antibiotics is determined depending on the method of excretion. Doses of sulfonamides, cephaloridin, methicillin, ampicillin and penicillin are reduced by 2-3 times. When taking polymyxin, neomycin, monomycin and streptomycin, even in small doses, complications may develop (neuritis of the auditory nerve, etc.). nitrofuran derivatives are contraindicated in patients with CRF.
Glycosides should be used with caution in the treatment of heart failure. The dosage decreases, especially with the development of hypokalemia. Patients with intermittent stage of CRF are prescribed hemodialysis during the exacerbation period. After the improvement of the patient’s condition, they are again transferred to conservative treatment.
Extracorporeal detoxification methods
The appointment of repeated courses of plasmapheresis is effective. When the terminal stage occurs and there is no effect from symptomatic therapy, the patient is prescribed regular hemodialysis (2-3 times a week). Transfer to hemodialysis is recommended with a decrease in creatinine clearance below 10 ml/min and an increase in its plasma level to 0.1 g/l. Choosing the tactics of therapy, it should be borne in mind that the development of complications in chronic renal failure reduces the effect of hemodialysis and excludes the possibility of kidney transplantation.
Prognosis and prevention
The prognosis for chronic renal failure is always serious. Sustained rehabilitation and significant prolongation of life is possible with timely hemodialysis or kidney transplantation. The decision on the possibility of these types of treatment is made by transplantologists and doctors of hemodialysis centers. Prevention provides for the timely detection and treatment of diseases that can cause CRF.