Prerenal acute renal failure develops with. Symptoms and treatment of acute renal failure. Treatment in the initial phase

Acute renal failure is a disease accompanied by a decrease in the excretory function of the kidneys.

In such a state, blood azotemia and pronounced electrolyte disturbances gradually increase.

In such cases, round-the-clock monitoring of the patient's condition is necessary.

All causes of acute renal failure can be divided into 3 groups:

Prerenal.
Renal.
Postrenal.

Prerenal causes of acute failure:

arterial hypotension;
volemia;
decentralization of blood supply;
disturbance of peripheral microcirculation.

There are the following types of shock - posthemorrhagic, infectious, traumatic. Each of them is capable of causing rapid death of renal nephrons.

Similar pathogenetic changes also develop against the background of rapid and profuse fluid loss during burns, vomiting, and an overdose of diuretic drugs (hypochlorothiazide, furosemide).

Renal failure of the kidneys occurs under the influence of the following nosological forms:

sepsis;
uremic-hemolytic syndrome;
kidney dysplasia;
systemic vasculitis;
lupus erythematosus;
nephropathy.

Acute death of renal nephrons develops when toxins enter the bloodstream, as well as when taking medications. In some patients, acute renal failure can be traced after x-ray studies (excretory radiography), the use of chemicals, anemia.

Postrenal insufficiency occurs with the following diseases:

Stenosis of the ureter.
Foreign body of the urinary tract.
Tumors of the urethra and pelvis.
Inflammation of the pelvicalyceal system.
Bacterial and viral infections.

With this type of disease, a blockade of the urinary tract is formed, leading to the expansion of the urinary tract above the narrowing area.

A similar situation occurs with urolithiasis, when a decrease in the lumen of the ureter is caused by a calculus.

Clinical picture (symptoms, classification and stages)

The clinical picture of the disease depends on the pathogenetic stage of acute renal failure:

initial;
oligoanuria;
polyuria;
recovery (reconvalescence).

At the initial stage of the disease, the clinical picture is not accompanied by severe symptoms. They form gradually. The only manifestation of the initial stage of acute renal failure may be oliguria (a decrease in daily diuresis by 10%). Additional signs of the disease are nausea, pallor, abdominal pain, icterus (yellowness of the skin and sclera).

The oliguric stage is characterized by a decrease in the level of diuresis by 25% and is combined with a decrease in the specific gravity of urine up to 1005. At the same time, the heart rate increases in order to normalize the total blood volume. With an increase in the concentration of potassium in the blood, convulsive contractions of the muscles appear.

Examination of the fundus in a patient in the oligouric stage of insufficiency reveals papilledema.

Such changes are quite dangerous, as they are evidence of the presence of small hemorrhages in the brain and other internal organs.

The polyuric degree of pathology is characterized by an increase in the level of diuresis, against which there is an increase in the level of potassium and uric acid in the blood. After its occurrence, the symptoms of blood intoxication disappear.

Pathogenetic classification

At the prerenal stage of acute kidney failure, the following pathogenetic links of the pathological process can be observed:

Decreased cardiac output;
Circulation disorder;
Narrowing of peripheral vessels;
Formation of shunts between capillaries.

All of the above pathogenetic changes without adequate treatment lead to the appearance of a renal form of insufficiency.

With such symptoms of acute renal failure, it is necessary to call emergency care and undergo a full examination by specialists.

What types of shock are combined with renal renal failure:

Septic.
Anaphylactic.
Hypovolemic.
Cardiogenic shock.
Dehydration.
Coma.

In 25% of cases, the renal form of the disease is due to inflammatory causes (glomerulo- and pyelonephritis), interstitial nephritis, vasculitis.

With this form of the disease, additional syndromes occur:

Hemorrhagic - small petechiae on the skin and in the vessels of the brain;
Hypertensive - an increase in blood pressure due to the activation of the renin-angiotensin-aldosterone system;
Nephrotoxic - a significant increase in urea and blood creatinine;
Myorenal syndrome - damage to the muscles, leading to an increase in the level of myoglobin in the blood;
Violation of electrolyte metabolism (hypophosphatemia, hypokalemia);
Intoxication - an increase in temperature, the appearance of c-reactive protein in the blood;
Allergic - an increase in the concentration of immunoglobulins in the blood.

The postrenal form of the disease occurs with the following diseases:

Fibrosis retroperitoneal

obstruction of the urinary tract;
tumors;
Schistosomiasis of the ureter and bladder;
narrowing of the urethra;
Papillitis necrotic;
spinal cord injury;
Fibrosis is retroperitoneal;
Constriction of the vessels of the nephron.

Diagnostics

Diagnosis of acute renal failure is based on the use of the following methods:

Clinical examination;
Urine and blood tests;
Clinical and instrumental methods.

It is important to start treatment of the disease in the early stages in order to prevent the death of the functional renal unit - the nephron.

The main task of the doctor, if a patient is suspected of having this pathology, is to determine the level of urine in the bladder (using ultrasound), to analyze the concentration of potassium and creatinine in the serum.

The next step in the diagnostic procedures is to determine the form of the disease (prerenal, renal or postrenal). First, it is necessary to exclude obstruction of the pelvis and urethra (ultrasound, excretory urography, endoscopy and radionuclide diagnostics).

You may not have guessed that the causes of the same kidney diseases in children, adults and the elderly may be different. Read more - as well as various methods of treatment - folk and conservative methods.

Read about the correct diet for dialysis patients.

And here is a detailed classification of the stages of chronic renal failure. Clinical picture and prevalence of the disease.

What do urine tests show?

In renal failure, urine and blood tests are an important diagnostic method that allows not only to identify the disease, but also to monitor the effectiveness of its treatment.

Indicators of differential laboratory diagnosis of types of acute renal failure are shown in the table:

Indicators	Norm	Acute renal failure
Indicators	Norm	prerenal	Renal	Postrenal
Diuresis (ml/day)	< 15000	< 500	varies	< 500
Relative density of urine	1025-1026	> 1020	1010	1010
Osmolarity of urine	400-600	> 400	< 400	< 400
Urine Na (mol/l)	15-40	< 20	> 30	> 40
Urea urine/plasma	20:1	> 10:1	< 4:1	< 8:1
Osmolarity urine/plasma	1,5-1- 2:1	< 1,1-1	> 1,5:1	< 1:1
Sodium excretion fraction %	< = 1	< 1	> = 2	> 1

What are the changes in the urine in acute kidney failure:

Reduced chlorine and sodium.
Increase in the ratio of blood creatinine to analogue in the urine.
The excreted fraction of sodium is less than 1.
The presence of protein cylinders and urine erythrocytes;
Lots of cellular debris;
The presence of polymorphonuclear leukocytes and eosinophils.
Determination of crystals of uric, oxalic acid.

The study of the electrolyte composition of urine is not the basis for establishing the form of acute renal failure.

The concentration of sodium and chlorine can vary significantly in the presence of concomitant diseases (nephritis, urolithiasis, nephropathy).

Complications

In renal failure, the following complications are observed:

Cardiovascular (hypertension and pulmonary edema);
Metabolic (hyperkalemia, hyponatremia, metabolic acidosis);
Neurological (coma and convulsions);
Hematological (anemia, hemolytic-uremic syndrome, bleeding);
Intestinal (nausea and vomiting);
Inflammatory (urinary infection, septicemia, wound infections).

To assess the degree and severity of complications, the following indicators are determined:

Specific gravity of urine.
Osmolarity of urine.
Sodium in the urine.
Blood/urine creatinine.
The study of urinary sediment.

Treatment of acute renal failure

Treatment of acute renal failure depends on the stage of the disease. At the initial stage of the pathology, the following procedures are carried out:

Restoration of blood flow;
Symptomatic treatment (vasodilators, hypotension, anti-inflammatory drugs);

In the stage of oligoanuria, the following manipulations should be carried out:

Jordan-Giovanetti Diet;
Hemodialysis;
Drinking mode;
The use of antibiotics.

Treatment at the stage of polyuric changes:

Correction of calcium and potassium in the blood.
Fluid intake.
The use of symptomatic agents.

In the postrenal form of the disease, it is necessary to restore the passage of urine. For these purposes, an obstacle should be removed - stones or tumors. Most often, operational methods are used for these purposes.

Dialysis procedures are used when drug therapy does not lead to the elimination of oligoanuria. In such a situation, a person connects to an "artificial kidney" - special equipment that helps remove toxins from the blood.

Treatment of the prerenal form of the disease is aimed at eliminating the etiological factors that led to acute renal failure.

If the disease occurs with hypovolemia or heart failure, beta-blockers are prescribed.

To restore the amount of circulating blood in shock, an infusion of detoxifying agents is prescribed:

Reopoliglyukin or polyglucin;
Ringer-Lock solution;
Intravenous administration of saline solutions.

When blood pressure is restored, an intravenous infusion of furosemide with dopamine should be given to reduce vasoconstriction.

Therapy of the renal form in most cases is carried out by the following methods:

alkalizing therapy;
The introduction of mannitol;
Use of glucose with sodium bicarbonate and furosemide.

The effectiveness of treatment is assessed by the daily increase in urine output and weight loss.

In toxic forms of acute renal failure, plasmapheresis and hemosorption are recommended.

Features of hemodialysis

Dialysis treatment for kidney failure should be started immediately for the following indications:

An increase in the level of urea in the blood daily by 20 mg.
With the threat of pulmonary edema against the background of an increase in the intracellular amount of fluid.
Renal anuria (lack of urination).
Irreversible course of acute renal failure (malignant hypertension, hemolytic uremic syndrome, cortical necrosis).

The choice of type of dialysis is determined by the form of kidney failure. If there is no severe overhydration, hemodialysis is rational. In elderly patients, children, with drug intoxication with a significant increase in creatinine levels, peritoneal dialysis is recommended.

Hemofiltration is carried out throughout the anuric stage of acute renal failure.

If renal function is slightly lost, hemofiltration should be carried out in an intermittent mode (at certain time intervals).

Types of dialysis treatment depending on the connection to the vessels:

Arterio-venous.
Veno-venous.

For hemodialysis, it is important to have a stable blood flow.

Forecast

With obstetric and gynecological forms of renal failure, mortality reaches 20%, with multiple organ failure - 100%, against the background of surgical interventions and injuries - 80-90%, dosage form - 70%.

Heart failure secondary to renal failure

The most unfavorable forms are anuric and oligoanuric. With them, pronounced hypercatabolism occurs, against which the concentration of potassium and other electrolytes in the blood increases. In such a situation, there is a high probability of joining heart failure and myocardial diseases.

Prevention

Prevention of acute renal failure consists in the timely detection and early treatment of diseases that lead to impaired renal function: arterial hypertension, atherosclerosis, vegetative-vascular dystonia, rheumatic diseases and autoimmune conditions.

Maintain genitourinary hygiene to prevent bacterial and viral kidney infections.

- this is a potentially reversible, sudden onset of a pronounced impairment or cessation of kidney function. Characterized by a violation of all renal functions (secretory, excretory and filtration), pronounced changes in water and electrolyte balance, rapidly increasing azotemia. Diagnosis is carried out according to clinical and biochemical blood and urine tests, as well as instrumental studies of the urinary system. Treatment depends on the stage of acute renal failure, includes symptomatic therapy, methods of extracorporeal hemocorrection, maintenance of optimal blood pressure and diuresis.

ICD-10

N17

General information

Acute renal failure is a suddenly developing polyetiological condition, which is characterized by severe impairment of kidney function and poses a threat to the patient's life. Pathology can be provoked by diseases of the urinary system, disorders of the cardiovascular system, endogenous and exogenous toxic effects, and other factors. The prevalence of pathology is 150-200 cases per 1 million population. Older people suffer 5 times more often than young and middle-aged people. Half of the cases of acute renal failure require hemodialysis.

Causes

Prerenal (hemodynamic) acute renal failure occurs as a result of an acute hemodynamic disorder, can develop in conditions that are accompanied by a decrease in cardiac output (with pulmonary embolism, heart failure, arrhythmia, cardiac tamponade, cardiogenic shock). Often the cause is a decrease in the amount of extracellular fluid (with diarrhea, dehydration, acute blood loss, burns, ascites caused by liver cirrhosis). It can be formed due to severe vasodilation in bacteriotoxic or anaphylactic shock.

Renal (parenchymal) acute renal failure is provoked by toxic or ischemic damage to the renal parenchyma, less often by an inflammatory process in the kidneys. Occurs when the renal parenchyma is exposed to fertilizers, poisonous fungi, salts of copper, cadmium, uranium and mercury. It develops with uncontrolled intake of nephrotoxic drugs (anticancer drugs, a number of antibiotics and sulfonamides). X-ray contrast agents and the listed drugs, prescribed in the usual dosage, can cause renal acute renal failure in patients with impaired renal function.

In addition, this form of acute renal failure is observed when a large amount of myoglobin and hemoglobin circulate in the blood (with severe macrohemagglobinuria, transfusion of incompatible blood, prolonged tissue compression during trauma, drug and alcohol coma). Less often, the development of renal acute renal failure is due to inflammatory kidney disease.

Postrenal (obstructive) acute renal failure is formed with acute obstruction of the urinary tract. It is observed with a mechanical violation of the passage of urine with bilateral obstruction of the ureters with stones. Less commonly occurs with tumors of the prostate gland, bladder and ureters, tuberculous lesions, urethritis and periurethritis, dystrophic lesions of the retroperitoneal tissue.

In severe combined injuries and extensive surgical interventions, the pathology is caused by several factors (shock, sepsis, blood transfusion, treatment with nephrotoxic drugs).

Symptoms of acute renal failure

There are four phases of acute renal failure: initial, oligoanuric, diuretic, recovery. At the initial stage, the patient's condition is determined by the underlying disease. Clinically, this phase is usually not detected due to the absence of characteristic symptoms. The circulatory collapse has a very short duration, so it goes unnoticed. Nonspecific symptoms of acute renal failure (drowsiness, nausea, lack of appetite, weakness) are masked by manifestations of the underlying disease, injury or poisoning.

At the oligoanuric stage, anuria rarely occurs. The amount of urine separated is less than 500 ml per day. Severe proteinuria, azotemia, hyperphosphatemia, hyperkalemia, hypernatemia, and metabolic acidosis are characteristic. Diarrhea, nausea, vomiting are noted. With pulmonary edema due to hyperhydration, shortness of breath and moist rales appear. The patient is lethargic, drowsy, may fall into a coma. Often develops pericarditis, uremic gastroenterocolitis, complicated by bleeding. The patient is susceptible to infection due to reduced immunity. Possible pancreatitis, stomatitis parotitis, pneumonia, sepsis.

The oligoanuric phase of acute renal failure develops within the first three days after exposure, usually lasting 10-14 days. Late development of the oligoanuric phase is considered a prognostically unfavorable sign. The period of oliguria can be shortened to a few hours or extended to 6-8 weeks. Prolonged oliguria occurs more often in elderly patients with concomitant vascular pathology. With a phase duration of more than a month, it is necessary to conduct a differential diagnosis to exclude progressive glomerulonephritis, renal vasculitis, renal artery occlusion, diffuse necrosis of the renal cortex.

The duration of the diuretic phase is about two weeks. Daily diuresis gradually increases and reaches 2-5 liters. There is a gradual restoration of water and electrolyte balance. Possible hypokalemia due to significant loss of potassium in the urine. In the recovery phase, further normalization of renal functions takes place, which takes from 6 months to 1 year.

Complications

The severity of disorders characteristic of renal failure (fluid retention, azotemia, impaired water and electrolyte balance) depends on the state of catabolism and the presence of oliguria. In severe oliguria, there is a decrease in the level of glomerular filtration, the release of electrolytes, water and nitrogen metabolism products is significantly reduced, which leads to more pronounced changes in the composition of the blood.

With oliguria, the risk of developing water and salt overload increases. Hyperkalemia is caused by insufficient excretion of potassium with a continuing level of its release from the tissues. In patients who do not suffer from oliguria, the potassium level is 0.3-0.5 mmol / day. More pronounced hyperkalemia in such patients may indicate an exogenous (blood transfusion, drugs, the presence of foods rich in potassium in the diet) or endogenous (hemolysis, tissue destruction) potassium load.

The first symptoms of hyperkalemia appear when the potassium level exceeds 6.0-6.5 mmol/L. Patients complain of muscle weakness. In some cases, flaccid tetraparesis develops. ECG changes are noted. The amplitude of the P waves decreases, the PR interval increases, and bradycardia develops. A significant increase in potassium concentration can cause cardiac arrest. In the first two stages of acute renal failure, hypocalcemia, hyperphosphatemia, and mild hypermagnesemia are observed.

The consequence of severe azotemia is the inhibition of erythropoiesis. Normochromic anemia develops. Immune suppression contributes to the occurrence of infectious diseases in 30-70% of patients with acute renal failure. Accession of infection aggravates the course of the disease and often becomes the cause of death of the patient. Inflammation in the area of postoperative wounds is revealed, the oral cavity, respiratory system, and urinary tract suffer. Sepsis is a common complication of acute renal failure.

There is drowsiness, confusion, disorientation, lethargy, alternating with periods of excitement. Peripheral neuropathy is more common in older patients. With acute renal failure, congestive heart failure, arrhythmia, pericarditis, and arterial hypertension may develop. Patients are concerned about the feeling of discomfort in the abdominal cavity, nausea, vomiting, loss of appetite. In severe cases, uremic gastroenterocolitis is observed, often complicated by bleeding.

Diagnostics

The main marker of acute renal failure is an increase in potassium and nitrogenous compounds in the blood against the background of a significant decrease in the amount of urine excreted by the body up to the state of anuria. The amount of daily urine and the concentration ability of the kidneys are evaluated according to the results of the Zimnitsky test. It is important to monitor such indicators of blood biochemistry as urea, creatinine and electrolytes, which makes it possible to judge the severity of acute renal failure and the effectiveness of ongoing therapeutic measures.

The main task in the diagnosis of acute renal failure is to determine its form. For this, ultrasound of the kidneys and sonography of the bladder are performed, which make it possible to identify or exclude obstruction of the urinary tract. In some cases, bilateral catheterization of the pelvis is performed. If, at the same time, both catheters freely passed into the pelvis, but no urine output is observed through them, it is safe to exclude the postrenal form of acute renal failure. If necessary, to assess the renal blood flow, ultrasound of the vessels of the kidneys is performed. Suspicion of tubular necrosis, acute glomerulonephritis, or systemic disease is an indication for a kidney biopsy.

Treatment of acute renal failure

In the initial phase, therapy is aimed primarily at eliminating the cause that caused impaired renal function. In shock, it is necessary to replenish the volume of circulating blood and normalize blood pressure. In case of poisoning with nephrotoxins, patients are washed with the stomach and intestines. The use in practical urology of such modern methods of treatment as extracorporeal hemocorrection allows you to quickly cleanse the body of toxins that caused the development of acute renal failure. For this purpose, hemosorption is carried out and. In the presence of obstruction, normal urine passage is restored. To do this, stones are removed from the kidneys and ureters, surgical removal of ureteral strictures and removal of tumors.

In the phase of oliguria, furosemide and osmotic diuretics are prescribed to stimulate diuresis. Dopamine is administered to reduce renal vasoconstriction. When determining the volume of fluid administered, in addition to losses during urination, vomiting and bowel movements, it is necessary to take into account losses during sweating and breathing. The patient is transferred to a protein-free diet, limit the intake of potassium from food. Drainage of wounds, removal of areas of necrosis is carried out. When choosing a dose of antibiotics, the severity of kidney damage should be taken into account.

Hemodialysis is prescribed when the level of urea rises to 24 mmol / l, potassium - up to 7 mmol / l. Indications for hemodialysis are symptoms of uremia, acidosis and hyperhydration. Currently, to prevent complications arising from metabolic disorders, nephrologists are increasingly conducting early and preventive hemodialysis.

Forecast and prevention

Mortality primarily depends on the severity of the pathological condition that caused the development of acute renal failure. The outcome of the disease is affected by the age of the patient, the degree of impaired renal function, the presence of complications. In surviving patients, renal function is restored completely in 35-40% of cases, partially - in 10-15% of cases. 1-3% of patients require permanent hemodialysis. Prevention consists in the timely treatment of diseases and the prevention of conditions that can provoke acute renal failure.

Renal insufficiency should be understood as a more or less pronounced violation of all kidney functions.

When characterizing the activity of the kidneys, it is necessary to distinguish between two concepts - the functions of the kidneys and the processes by which these functions are provided. Kidney functions: 1) maintaining a constant volume of body fluids, their osmotic concentration and ionic composition; 2) regulation of acid-base balance; 3) excretion of products of nitrogen metabolism and foreign substances; 4) saving or excretion of various organic substances (glucose, amino acids, etc.) depending on the composition of the internal environment of the body; 5) metabolism of carbohydrates and proteins; 6) secretion of biologically active substances - production of erythropoietin and renin (endocrine function of the kidneys).

This variety of kidney functions is provided by a number of processes occurring in their parenchyma: ultrafiltration in the glomeruli, reabsorption and secretion in the tubules, synthesis of new compounds, including biologically active substances, in special structures of the renal parenchyma, etc.

The development of morphological changes in the kidney under the influence of various factors of aggression causes inhibition or cessation of the processes that provide kidney function, which manifests itself clinically as renal failure.

Distinguish between acute renal failure (ARF) and chronic renal failure (CRF). The different pathogenesis of these pathological conditions and various morphological changes in the renal structures in acute renal failure and chronic renal failure underlie their differences in the clinical picture, treatment and prognosis.

Features and diversity of kidney function, the complexity of the biochemical and physiological processes by which these functions are provided, are reflected in the specifics of the methods of treatment of acute renal failure and chronic renal failure. In particular, we are talking about extracorporeal methods of treatment, which currently allow saving the lives of most patients with acute renal failure and prolonging the life of patients with chronic renal failure for many years.

OPN- this is a sudden, usually reversible, violation of all functions of both kidneys or a single kidney, manifested by a significant decrease or absence of urine output, retention of nitrogenous wastes and metabolic products in the body, and a violation of the acid-base and water-electrolyte balance.

There are three main groups of causes for the development of acute renal failure: prerenal, renal and postrenal.

Prerenal factors for the development of acute renal failure. The main causes of acute renal failure are renal ischemia caused by a decrease in cardiac output (cardiogenic shock), a decrease in BCC (burns, uncontrollable vomiting, bleeding), extensive surgical interventions (bleeding, sepsis, shock). In case of circulatory failure in the kidney (blood pressure drop below 70-60 mm Hg), blood is shunted through the vessels of the pericerebral layer, bypassing the cortical one. This leads to the fact that the cells of the epithelium of the tubules of nephrons under conditions of ischemia are necrotic and exfoliate into the lumen of the tubules, causing obstruction of their lumen and rupture of the basement membrane of the tubules. This leads to the cessation of glomerular filtration. In such a situation, edema of the kidney parenchyma develops and a complete loss of its function.

To renal factors causing the development of acute renal failure include toxic effects on nephron structures (poisoning with heavy metal salts, acids, poisonous mushrooms, nephrotoxic drugs, alcohol surrogates) and immunoallergic kidney damage (glomerulonephritis, collagenoses). Some of these aggressive factors cause damage to the epithelium of the tubules of nephrons, while others cause damage to the glomeruli.

To postrenal factors include occlusion of the upper urinary tract by stones, compression of the ureters by tumors, iatrogenic obstruction of the ureters. In other words, the development of postrenal acute renal failure is based on the cessation of the outflow of urine from the kidneys, caused by any mechanical reasons.

You need to know that with acute renal failure, the patient develops: 1) hyperhydration caused by water retention in the body;
2) hyperazotemia caused by the accumulation of nitrogenous slags in the body; 3) dyselectrolytemia in the form of hyperkalemia, hyponatremia; 4) metabolic acidosis due to a decrease in the content of bicarbonates in the blood; 5) endotoxemia due to the accumulation in the blood of "medium molecules" (medium molecular weight peptides with a mass of 500 to 5000 daltons).

Inadequate treatment or lack of treatment of acute renal failure quickly leads to homeostasis disorders that are incompatible with life.

Clinical picture of OPN. The leading symptom of acute renal failure is oligo- or anuria, followed by the development of a violation of all links of homeostasis.

During acute renal failure of renal and prerenal genesis, 4 stages are distinguished: I - initial, the duration coincides with the duration of the action of aggression factors (shock, poisoning) and the clinical picture is completely due to these factors, stage II - oligoanuric; Stage III - restoration of diuresis (diuretic); Stage IV - restoration of kidney function (recovery). The duration of all these stages depends on the degree of kidney damage.

OPN diagnostics. Based on the history, characteristic clinical picture and laboratory data, it is not difficult to recognize ARF. After an injury or exposure to a person of any toxic factor (poisoning with exogenous poisons, heavy metals, etc.), the resulting decrease in diuresis, the appearance of hypostenuria against the background of azotemia and the general serious condition of the patient makes it possible to reasonably suspect the development of acute renal failure.

In each case of acute renal failure, urinary tract obstruction must be ruled out. For this, the patient needs to perform an ultrasound of the kidneys and bladder. Expansion of the pyelocaliceal systems of the kidneys in a patient with signs of acute renal failure indicates postrenal genesis of renal failure. In order to confirm or exclude postrenal genesis of acute renal failure, cystoscopy and ureteral catheterization are sometimes performed, which provides information about the patency of the ureters.

The main role in the diagnosis of acute renal failure is played by biochemical blood tests. There is an increase in the content of urea and creatinine, hyperkalemia; metabolic acidosis; increase in the content of "medium molecules". In the analysis of urine, proteinuria, cylindruria, leukocyturia are noted, epithelial cells of the renal tubules appear.

Treatment of acute renal failure

Treatment of acute renal failure depends on the causes that caused it. Therapy begins with conservative measures aimed at eliminating the underlying disease, which resulted in acute renal failure: in case of blood loss - replacement transfusion of erythrocyte mass, in case of poisoning with exogenous poisons - gastric lavage and the use of antidotes, in case of urinary tract occlusion - immediate restoration of urine outflow from the kidneys.

Patients with pre- or renal acute renal failure are given osmotic diuretics or lasix, fluids are transfused in an amount equal to the volume of fluid lost per day + 400 ml.

With continued oligo- or anuria for more than 3-4 days, hemodialysis on an artificial kidney apparatus is necessary. In addition, hemodialysis is indicated in cases of progressive deterioration of the patient's condition, with azotemia more than 30 mmol / l; hyponatremia (below 125 mmol/l); hyperkalemia (above 6 mmol / l); with decompensated metabolic acidosis (pH< 7,35). При интенсивном накоплении среднемолекулярных пептидов («средних молекул») параллельно с гемодиализом проводится гемосорбция или лимфосорбция, плазмаферез.

The prognosis for acute renal failure depends on the cause that caused it, the timeliness and adequacy of the treatment. Most patients recover, but kidney function may not recover - chronic renal failure (CRF) develops. The phase of oliguria or anuria is replaced by the recovery phase of diuresis, which passes into the recovery phase with complete or partial restoration of kidney function.

CRF- a complication of progressive diseases of the kidney parenchyma or a single kidney. CRF should be considered as a clinical syndrome caused by irreversible (unlike AKI), usually progressive nephron damage due to various chronic kidney lesions.

Diseases complicated by the development of chronic renal failure include: chronic glomerulonephritis, chronic pyelonephritis, anomalies of the kidneys and ureters, polycystic kidney disease, collagenoses, kidney diseases of metabolic origin (diabetes mellitus, gout with uric acid nephropathy), hypertension, urolithiasis, tuberculosis, amyloidosis of the kidneys.

In the pathomorphology of chronic renal failure, the leading is the death and fibrous replacement of most nephrons. The remaining nephrons with an increase in the functional load compensatory hypertrophy. Increased urine flow in the tubules disrupts reabsorption and an increasing amount of urea falls on each functioning nephron, which stimulates the development of osmotic diuresis. Thus, the minimum required number of nephrons for some time provides the "cleansing" function of the kidneys. This explains the long-lasting hypostenuria and isosthenuria in chronic renal failure.

In its course, chronic renal failure goes through 4 stages: I - latent, II - compensated, III - intermittent, IV - terminal.

Diagnosis of HPN. In the diagnosis of great importance is the anamnesis, the determination of urea and creatinine in the blood, electrolytes, the study of glomerular filtration and tubular reabsorption, the Zimnitsky test, and radionuclide renography. With chronic renal failure in the blood, the content of urea and creatinine, potassium increases, glomerular filtration and tubular reabsorption decrease, blood pH decreases. On the renograms, an afunctional or parenchymal type of curves and a decrease in blood clearance for iodine hippuran are noted. The purification factor (Winter's factor) exceeds 50%. In Zimnitsky's sample, a monotonically low density of urine is noted throughout the day.

Stages of CRF can be diagnosed based on the laboratory parameters shown in the table.

Table. Determining the stage of chronic renal failure

Treatment of HPN. Conservative treatment. Its objectives are to influence water and electrolyte disturbances, acidosis, cardiovascular insufficiency, arterial hypertension and other disorders of the function of internal organs. A low-protein diet is recommended (no more than 20-25 grams of protein per day) with a predominant content of potatoes and carbohydrates, with arterial hypertension and azotemia - a salt-free diet. With edema, osmotic diuretics are prescribed. In the terminal stage of chronic renal failure, renal replacement therapy is performed: hemodialysis, peritoneal dialysis, or kidney transplantation.

The principle of operation of the device ARTIFICIAL KIDNEY. In the device "artificial kidney" hemodialysis is carried out. Dialysis is understood as the exchange of substances between the blood of a patient with renal insufficiency and dialysis solution passing through a semipermeable membrane. In the dialyzers of the "artificial kidney" devices, 2 types of dialysis membranes are used: cellulose and synthetic, which ensure the passage of small molecules of various toxic substances - the end products of metabolism - proteins and water. On one side of the semi-permeable membrane is the patient's blood, on the other - dialysate solution. Blood waste and water pass through the membrane into the dialysis fluid (Figure 7-1). Thus, the blood is cleansed of toxins. The duration of a hemodialysis session is 4-6 hours.

Rice. 7-1. Scheme of the device "artificial kidney"

kidney transplant

The indication for kidney transplantation, as well as for hemodialysis, is CRF in the terminal stage.

Kidney donors can be close relatives of the patient (brother, sister, mother, father), but a kidney can be transplanted from a corpse. Most often, kidney donors are those who died after a traumatic brain injury incompatible with life.

The kidney is transplanted into the iliac region. The renal vein is anastomosed end-to-side with the external iliac vein (Fig. 7-2), the renal artery is anastomosed with the internal iliac artery end-to-end (Fig. 7-3), and the ureter is transplanted into the bladder.

Rice. 7-2. Kidney transplant.

End-to-side anastomosis of the renal vein with the common iliac vein

Rice. 7-3. Kidney transplant.

Anastomosis between the renal artery and the internal iliac artery "end to end"

Failure of the functioning of two kidneys, provoked by a weakening of the blood supply, a delay in glomerular filtration is called acute renal failure (ARF).

The result is an absolute stop in the removal of toxins, failure of acid-base, electrolyte, water balance. Competent therapy prevents painful processes.

Acute kidney failure is the failure of both kidneys to function.

According to medical statistics, the disease affects 200 people out of 1 million.

Features of renal failure

Acute renal failure - contractions, stops the work of the kidneys, provoking an increase in metabolites of nitrogen metabolism, metabolic failure. The pathology of the nephron is due to a reduction in blood supply, a reduction in oxygen.

The pathology of acute renal failure for the occurrence requires from a couple of hours to a week, lasts more than a day. An earlier visit to the doctor provides an absolute resumption of the work of the affected organ. OPN becomes an exacerbation of painful pathologies, is divided into forms:

Hemodynamic (perineral), caused by a sharp failure of hemodynamics. It is characterized by a decrease in blood supply, a decrease in the rate of glomerular filtration. Failures of this type are due to a decrease in the amount of pulsating blood. If there is no restoration of blood supply, then the death of renal tissues is likely.
Parenchymal (renal) - occurs due to toxic or ischemic effects on the kidney parenchyma or acute inflammation. As a result, damage to the integrity of the tubules occurs, the release of their entrails into the tissues.
Obstructive (postrenal) - is formed after the resulting obstruction of the urinary canals. This type provides for the preservation of functions, urination will be difficult.

According to the level of preservation of diuresis, the neoliguric, oliguric form is divided.

Causes of acute renal failure

The etiology of the disease is distinguished by form. Factors in the formation of prerenal acute renal failure include:

reduction in cardiac output;
blockage of the pulmonary artery;
surgical interventions, trauma with blood loss;
tissue damage by high temperatures;
loss of large water and salts due to loose stools, vomiting;
taking diuretics;
drop in vascular tone.

Prerequisites for the renal form of acute renal failure:

toxic effect on the kidney tissue of poisonous plants, copper, mercury salts;
uncontrolled use of drugs (anti-blastoma drugs, antimicrobials and sulfonamides);
contrast agents, drugs can cause pathology in humans;
elevated levels of myoglobin with prolonged tissue compression during trauma, drug, alcohol coma;
inflammatory kidney disease.

There are many reasons for the development of the disease

Factors in the development of postrenal acute renal failure are:

pathology of the cardiac apparatus;
disruptions in the rhythm of the heartbeat;
cardiac tamponade, dehydration;
damage to body tissues by high temperatures;
ascites, low blood pressure;
blockage of blood vessels that carry blood to the kidneys;
toxic effect of toxic substances;
presence of inflammatory diseases.

In trauma and extensive surgery, the formation of acute renal failure is caused by: shock, infection or blood transfusion, therapy with nephrotoxic drugs.

Symptoms of acute renal failure

Distinctive features are characterized by development. There is an aggravation of the patient's well-being, failure of the functioning of organs. Symptoms of the manifestation of acute renal failure are divided into types according to stages.

The initial stage is accompanied by peripheral edema, weight gain. The primary phase is not detected due to the absence of signs. The circulatory crisis that appears at the stage has a duration, proceeds imperceptibly. Nonspecific signs of renal failure (muscle impotence, nausea, headache) are masked by the symptoms of a background illness - shock, injury or poisoning.

The initial stage is accompanied by an increase in weight

If acute glomerulonephritis is a prerequisite for acute renal failure, blood clots in the urine and back pain are observed. The initial phase of acute renal failure is accompanied by low blood pressure, pale skin color, accelerated heartbeat, and reduced diuresis.

Oligoanuria is considered a severe stage. It poses a threat to the life of the patient, accompanied by signs:

reducing or stopping the separation of urine;
poisoning with metabolites of nitrogen metabolism, expressed in the form of nausea, vomiting, loss of appetite;
increase in blood pressure;
difficulty concentrating, fainting;
coma;
swelling of connective tissue and internal organs;
weight gain from excess fluid in the body.

The subsequent course of acute renal failure is determined by the effectiveness of treatment in the second phase. A positive result ensures the onset of a special stage. There is an increase in diuresis, polyuria is formed. Fluid is eliminated from the body, puffiness is reduced, blood will be cleansed of toxins.

The phase of polyuria carries the danger of dehydration, electrolyte imbalance. A month later, diuresis normalizes, a recovery stage appears, which lasts up to 12 months.

With ineffective therapy, the terminal phase of acute renal failure is formed with the risk of mortality. Manifested in the form of symptoms:

difficulty breathing, coughing in the lungs;
expectoration of sputum with blood droplets;
fainting, coma;
spasm, convulsions;
critical palpitations.

The disease affects the body, provokes the development of atrophy of the heart muscle, pericarditis, encephalopathy, weakening of the immune system.

Diagnosis of kidney failure

The process of diagnosing includes the doctor's actions:

study of the anamnesis of pathology, patient complaints;
a study of the life history (whether the organs were injured, whether the patient had poisoning, blood loss, the presence of chronic renal ailments, diabetes mellitus), the contingency of working or living conditions with regular intoxication (paints and varnishes, solvents);
a complete assessment of the general condition of the patient is carried out (degree of consciousness, color of the skin surface, blood pressure indicators), the study of the urinary system with the help of palpation (palpation), light tapping with the edge of the palm in the lumbar region (may be accompanied by pain in the affected side);
blood tests: the presence of anemia (a decrease in the degree of hemoglobin and the number of red blood cells, due to the production of a hormone by the kidneys that ensures the production of red blood cells), an increase in protein breakdown products - creatinine, urea;
study of urine - a decrease in the volume of its production, the appearance of protein in the urine, an increase in urea, creatinine (eliminate the kidneys);
study of electrolytes, urinary components for probable renal pathologies;
ultrasound examination of the kidneys;
examination of the urea, urethra with optical equipment;
radionuclide methods - allow you to visualize the functional, anatomical structure of organs, determine the type of damage to tissues or the urinary apparatus, inflammatory features, the presence of stones or tumors;
according to indications (in case of a prolonged course of acute renal failure or its unknown etiology, a kidney biopsy is performed).

The doctor diagnoses the disease

Information about the size of the organ will not be superfluous. A decrease in size indicates the presence of chronic insufficiency.

Emergency care for illness

With acute renal failure syndrome, emergency care involves calling an ambulance or quickly transporting the patient to the hospital of a medical institution, then the patient must be provided with:

bed rest;
body warming;
removal from hypovolemia and shock (tachycardia, hypotension, shortness of breath, cyanosis of the skin, mucous tissues, anuria, dehydration);
jet introduction of warm salt solution "Trisol";
active therapy for sepsis;
intravenous drip injection of Dopamine provides improved blood circulation. Heparin is administered intravenously, its drip administration is carried out.

Treatment is best done in a hospital.

The resumption of kidney function occurs during compensation of the intravascular volume of fluid, therapy for blood poisoning, stopping the intake of nephrotoxic drugs.

Treatment of acute renal failure

At the first stage of the disease, therapy involves the elimination of the factor that provoked acute renal failure. In the presence of shock, it is required to compensate for the volume of circulating blood, to adjust blood pressure indicators.

The use of innovative methods by urologists, such as extracorporeal hemocorrection, provides cleansing of the body from poisons that caused the formation of acute renal failure. Help hemosorption, plasmapheresis. In the presence of obstructive signs, the normal passage of urine is restored. To do this, stones are removed from the kidneys, ureters.

Hemosorption procedure

The oliguric phase is accompanied by the appointment of furosemide, osmotic diuretics that stimulate diuresis. When setting the size of the injected fluid, excluding losses during urination, vomiting, bowel movements, sweating and breathing should be taken into account.

The patient is assigned protein nutrition, limit the intake of potassium with food. Wounds are drained, areas affected by necrosis are eliminated. The dosage of antibiotics is based on the severity of kidney damage.

Possible complications of the disease

The initiating and supporting stages of acute renal failure are accompanied by failures in the removal of nitrogen metabolism products, water, electrolytes and acids. The manifestation of changes in the chemical structure of the blood is due to oliguria, the process of catabolism in the patient.

The degree of glomerular filtration is noted in comparison with patients without oliguria. In the former, more nitrogen metabolism, water, and electrolytes are released with urine.

Failures in acute renal failure without oliguria in patients are less pronounced than in patients affected by pathology.

The normal increase in the concentration of potassium in the blood serum in patients without oliguria and catabolism is 0.3 - 0.5 mmol / day. Large volumes indicate a potassium load of the endogenous or exogenous type, as well as the release of potassium from cells due to acidemia.

The disease can cause complications

Severe consequences of the pathology may include uremia, as an independent intoxication of the body with the products of protein metabolism. There is a failure in the functioning of organs and systems:

hyperkalemia, which provokes changes in the ECG, as a result there will be a cardiac arrest. Pathology affects the development of muscle weakness and tetraparesis;
blood changes - suppression of hematopoietic function, production of red blood cells. The duration of the existence of erythrocytes decreases, anemia begins to develop;
suppression of the immune system, which causes the appearance of diseases of an infectious type, the addition of an infection aggravates the course of the disease and often leads to death;
manifestations of neurological failures - weakness, clouding of consciousness, a feeling of disorientation, slowness, followed by stages of arousal;
pathologies from the cardiovascular apparatus - arrhythmia, pericarditis, arterial hypertension;
malfunctions of the gastrointestinal tract - discomfort in the peritoneum, nausea, lack of appetite. In acute situations, the development of uremic gastroenterocolitis is likely;
the last stage in the development of uremia is uremic coma - the patient sinks into an unconscious state, severe failures in the functioning of the respiratory and cardiovascular apparatus are formed.

Competently conducted therapy ensures the complete reversibility of the disease, except for its most severe cases. The outcome of the disease depends on the age of the patient, the level of impaired renal function, and the presence of complications.

In a certain proportion of patients, kidney function is restored completely, 1-3% require hemodialysis.

Acute renal failure (ARF) is a rapid, but reversible, depression of renal function, sometimes to the stage of complete failure of one or both organs. Pathology is deservedly characterized as a critical condition that requires immediate medical intervention. Otherwise, the risk of an unfavorable outcome in the form of a loss of organ efficiency increases greatly.

Acute renal failure

The kidneys are the main "filters" of the human body, the nephrons of which continuously pass blood through their membranes, removing excess fluid and toxins with urine, sending the necessary substances back into the bloodstream.

The kidneys are organs without which human life is impossible. Therefore, in a situation where, under the influence of provoking factors, they cease to fulfill their functional task, doctors provide a person with emergency medical care, diagnosing him with acute renal failure. Somatic pathology code according to ICD-10 - N17.

To date, statistical information makes it clear that the number of people facing this pathology is growing every year.

Etiology

The causes of djpybryjdtybz acute renal failure are as follows:

Pathologies of the cardiovascular system that disrupt the process of blood supply to all organs, including the kidneys:
- arrhythmia;
- atherosclerosis;
- heart failure.
Dehydration against the background of the following ailments, which is the cause of changes in blood parameters, or rather, an increase in its prothrombin index, and, as a result, difficult work of the glomeruli:
- dyspeptic syndrome;
- extensive burns;
- blood loss.
Anaphylactic shock, which is accompanied by a sharp decrease in blood pressure, which adversely affects the functioning of the kidneys.
Acute inflammatory phenomena in the kidneys, which lead to damage to organ tissues:
- pyelonephritis.
A physical obstruction to the outflow of urine in urolithiasis, which first leads to hydronephrosis, and then, due to pressure on the tissues of the kidneys, to damage to their tissues.
Taking nephrotoxic drugs, which include a contrast composition for x-rays, causes poisoning of the body, which the kidneys cannot cope with.

OPN classification

The process of acute kidney failure is divided into three types:

Prerenal acute renal failure - the cause of the disease is not directly related to the kidneys. The most popular example of the prerenal type of acute renal failure can be called disorders in the work of the heart, because the pathology is often called hemodynamic. Less often, it occurs against the background of dehydration.
Renal acute renal failure - the root cause of the pathology can be found in the kidneys themselves, and therefore the second name of the category is parenchymal. Renal functional insufficiency in most cases results from acute glomerulonephritis.
Postrenal acute renal failure (obstructive) is a form that occurs when the urinary excretion pathways are blocked by calculi and the subsequent violation of the outflow of urine.

Classification of acute renal failure

Pathogenesis

AKI develops over four periods, which always follow in this order:

initial stage;
oliguric stage;
polyuric stage;
recovery.

The duration of the first stage can last from several hours to several days, depending on what is the root cause of the disease.

Oliguria is a term that briefly refers to a decrease in the volume of urine. Normally, a person should allocate approximately the amount of fluid that he consumed, minus the part “spent” by the body on sweating and breathing. With oliguria, the volume of urine becomes less than half a liter, out of direct relation to the amount of fluid drunk, which entails an increase in fluid and decay products in the tissues of the body.

The complete disappearance of diuresis - happens only in extremely severe cases. And statistically it rarely happens.

The duration of the first stage depends on how quickly adequate treatment was started.

Polyuria, on the contrary, means an increase in diuresis, in other words, the amount of urine can reach five liters, although 2 liters of urine per day is already a reason for diagnosing polyuric syndrome. This stage lasts about 10 days, and its main danger is that the body loses the substances it needs along with urine, as well as dehydration.

After the completion of the polyuric stage, a person, with a favorable development of the situation, recovers. However, it is important to know that this period may be delayed for one year, during which deviations in the interpretation of the analyzes will be detected.

Stages of acute renal failure

Clinical picture

The initial stage of acute renal failure does not have specific symptoms by which the disease could be unmistakably recognized, the main complaints during this period are:

loss of strength;
headache.

The symptomatic picture is supplemented by signs of the pathology that caused acute renal failure:

With oliguric syndrome against the background of acute renal failure, the symptoms become specific, easily recognizable and fit into the overall picture of the pathology:
- decrease in diuresis;
- dark foamy urine;
- dyspepsia;
- lethargy;
- wheezing in the chest due to fluid in the lungs;
- susceptibility to infections due to reduced immunity.
The polyuric (diuretic) stage is characterized by an increase in the amount of urine excreted, so all the patient's complaints stem from this fact, and the fact that the body loses a large amount of potassium and sodium with urine:
- violations in the work of the heart are fixed;
- hypotension.
The recovery period, which takes from 6 months to one year, is characterized by fatigue, changes in the results of a laboratory study of urine (specific gravity, erythrocytes, protein), blood (total protein, hemoglobin, ESR, urea,).

Diagnostics

Diagnosis of OPN is carried out using:

questioning and examining the patient, compiling his anamnesis;
a clinical blood test showing low hemoglobin;
a biochemical blood test, which detects elevated creatinine, potassium, urea;
diuresis monitoring, that is, control over how much liquid (including soups, fruits) a person consumes in 24 hours, and how much he excretes;
the ultrasound method, with acute renal failure more often showing the physiological size of the kidneys, a decrease in size indicators is a bad sign, indicating tissue damage, which may be irreversible;
nephrobiopsy - taking a piece of an organ with a long needle for microscopic examination; performed infrequently due to the high degree of trauma.

Treatment

Therapy of acute renal failure occurs in the intensive care unit of the hospital, less often in the nephrology department of the hospital.

All medical manipulations carried out by a doctor and medical staff can be divided into two stages:

Identification of the root cause of the pathological condition is carried out using diagnostic methods, the study of symptoms, specific complaints of the patient.
Eliminating the cause of acute renal failure is the most important stage of treatment, because without treating the root cause of the disease, any therapy will be ineffective:
- when a negative effect of nephrotoxins on the kidneys is detected, extracorporeal hemocorrection is used;
- when an autoimmune factor is detected, glucocorticosteroids (Prednisolone, Metipred, Prenisol) and plasmapheresis are prescribed.
- in case of urolithiasis, medical litholysis or surgical intervention is performed to remove stones;
- antibiotics are prescribed for infection.

At each stage, the doctor adjusts the appointment, based on the symptomatic picture at the moment.

During oliguria, it is necessary to prescribe diuretics, a strict diet with a minimum amount of protein and potassium, and, if necessary, hemodialysis.

Hemodialysis - a procedure for cleansing the blood of decay products and removing excess fluid from the body, has an ambiguous attitude from nephrologists. Some doctors argue that prophylactic hemodialysis for AKI is necessary in order to reduce the risk of complications. Other experts warn of a trend towards a complete loss of kidney function since the introduction of artificial blood purification.

During the period of polyuria, it is important to replenish the patient's missing blood volume, restore the electrolyte balance in the body, continue diet No. 4, and beware of any infection, especially when taking hormonal drugs.

General principles for the treatment of acute renal failure

Predictions and Complications

AKI against the background of proper treatment has a favorable prognosis: after the disease, only 2% of patients need lifelong hemodialysis.

Complications from acute kidney failure are associated with, that is, with the process of poisoning the body with its own decay products. As a result, the latter are not excreted by the kidneys with oliguria or with a low rate of blood filtration by glomeruli.

Pathology leads to:

violation of cardiovascular activity;
anemia;
increased risk of infections;
neurological disorders;
dyspeptic disorders;
uremic coma.

It is important to note that in acute nephrological insufficiency, in contrast to chronic, complications rarely occur.

Prevention

Prevention of OOP is as follows:

Avoid taking nephrotoxic drugs.
Timely treat chronic diseases of the urinary and vascular system.
Monitor blood pressure, if signs of chronic hypertension are detected, contact a specialist immediately.

On the video about the causes, symptoms and treatment of acute kidney failure: