Treatment of acute renal failure must begin with the treatment of the underlying disease that caused it.
To assess the degree of fluid retention in the patient's body, daily weighing is desirable. For a more accurate determination of the degree of hydration, the volume of infusion therapy and indications for it, it is necessary to install a catheter in the central vein. You should also take into account the daily urine output, as well as the patient's blood pressure.
In prerenal acute renal failure, it is necessary to restore the BCC as soon as possible and normalize blood pressure.
For the treatment of renal acute renal failure caused by various substances of a medicinal and non-medicinal nature, as well as some diseases, it is necessary to start detoxification therapy as soon as possible. It is desirable to take into account the molecular weight of the toxins that caused acute renal failure, and the clearance capabilities of the applied method of efferent therapy (plasmapheresis, hemosorption, hemodiafiltration or hemodialysis), the possibility of the earliest possible administration of the antidote.
In postrenal acute renal failure, immediate drainage of the urinary tract is necessary to restore adequate urine flow. When choosing the tactics of surgical intervention on the kidney in conditions of acute renal failure, even before the operation, information about the sufficient function of the contralateral kidney is needed. Patients with a single kidney are not so rare. During the stage of polyuria, which usually develops after drainage, it is necessary to control the fluid balance in the patient's body and the electrolyte composition of the blood. The polyuric stage of acute renal failure may present with hypokalemia.
Medication for acute renal failure
With undisturbed gastrointestinal passage, adequate enteral nutrition is required. If it is impossible, the need for proteins, fats, carbohydrates, vitamins and minerals is satisfied with the help of intravenous nutrition. Taking into account the severity of glomerular filtration disorders, protein consumption is limited to 20-25 g per day. The required caloric intake should be at least 1500 kcal / day. The amount of fluid required by the patient before the development of the polyuric stage is determined based on the volume of diuresis for the previous day and an additional 500 ml.
The greatest difficulties in treatment are caused by the combination of acute renal failure and urosepsis in a patient. The combination of two types of uremic and purulent intoxication at once significantly complicates treatment, and also significantly worsens the prognosis for life and recovery. When treating these patients, it is necessary to use efferent methods of detoxification (hemodiafiltration, plasmapheresis, indirect electrochemical oxidation of blood), the selection of antibacterial drugs based on the results of bacteriological analysis of blood and urine, as well as their dosage taking into account the actual glomerular filtration.
Treatment of a patient with hemodialysis (or modified hemodialysis) cannot be a contraindication to surgical treatment of diseases or complications that led to acute renal failure. Modern possibilities of monitoring the blood coagulation system and its drug correction allow avoiding the risk of bleeding during operations and in the postoperative period. For efferent therapy, it is advisable to use short-acting anticoagulants, for example, sodium heparin, the excess of which can be neutralized by the end of treatment with an antidote - protamine sulfate; sodium citrate can also be used as a coagulant. To control the blood coagulation system, a study of the activated partial thromboplastin time and determination of the amount of fibrinogen in the blood are usually used. The method for determining the time of blood clotting is not always accurate.
Treatment of acute renal failure even before the development of the polyuric stage requires the appointment of loop diuretics, for example, furosemide up to 200-300 mg per day in divided doses.
To compensate for catabolic processes, anabolic steroids are prescribed.
With hyperkalemia, intravenous administration of 400 ml of 5% glucose solution with 8 IU of insulin, as well as 10-30 ml of 10% calcium gluconate solution is indicated. If it is not possible to correct hyperkalemia by conservative methods, then the patient is indicated for emergency hemodialysis.
Surgical treatment of acute renal failure
To replace kidney function during oliguria, you can use any method of blood purification:
- hemodialysis;
- peritoneal dialysis;
- hemofiltration;
- hemodiafiltration;
- low-flow hemodiafiltration.
In case of multiple organ failure, it is better to start with low-flow hemodiafiltration.
Treatment of acute renal failure: hemodialysis
Indications for hemodialysis or its modification in chronic and acute renal failure are different. In the treatment of acute renal failure, the frequency, duration of the procedure, dialysis load, filtration rate and dialysate composition are selected individually at the time of examination, before each treatment session. Hemodialysis treatment is continued, preventing an increase in blood urea levels above 30 mmol / l. With the resolution of acute renal failure, the concentration of blood creatinine begins to decrease earlier than the concentration of blood urea, which is regarded as a positive prognostic sign.
Emergency indications for hemodialysis (and its modifications):
- "Uncontrolled" hyperkalemia;
- severe overhydration;
- hyperhydration of the lung tissue;
- severe uremic intoxication.
Scheduled indications for hemodialysis:
- the urea content in the blood is more than 30 mmol / l and / or the concentration of creatinine is more than 0.5 mmol / l;
- pronounced clinical signs of uremic intoxication (such as uremic encephalopathy, uremic gastritis, enterocolitis, gastroenterocolitis);
- overhydration;
- severe acidosis;
- hyponatremia;
- a rapid (within several days) increase in the content of uremic toxins in the blood (daily increase in the urea content, exceeding 7 mmol / l, and creatinine - 0.2-0.3 mmol / l) and / or a decrease in urine output
With the onset of the stage of polyuria, the need for hemodialysis treatment disappears.
Possible contraindications for efferent therapy:
- afibrinogenemic bleeding;
- unreliable surgical hemostasis;
- parenchymal bleeding.
A two-way catheter installed in one of the central veins (subclavian, jugular, or femoral) is used as a vascular access for dialysis treatment.
Acute renal failure (ARF) is a rapid, acute decrease or complete cessation of all kidney functions due to severe damage to most of the renal tissue, resulting in the accumulation of protein waste products in the body.
Due to the violation of the excretory (excretory) function of the kidneys, nitrogenous slags enter the human blood, which, during normal body activity, are removed along with the urine. Their number increases, the general condition of the patient worsens, the metabolism is significantly disturbed. The disease is also characterized by a sharp decrease in the amount of urine excreted (oliguria) to its complete absence (anuria).
In most cases, acute renal failure is a reversible process, but in the absence of timely medical care and the formation of a deep lesion of the renal tissue, the process becomes irreversible and becomes chronic.
Diagnosis of the disease is carried out on the basis of data from clinical and biochemical analyzes of blood and urine, as well as instrumental studies of the urinary system.
Treatment depends on the current stage of acute renal failure.
Etiology of Acute Renal Failure (ARF)
The occurrence and condition of an arrester depends on the reasons, which can be conditionally divided into three groups:
- Prerenal. Collapse, shock, severe arrhythmias, sepsis, heart failure, poor circulation, a significant decrease in circulating blood volume (as a result of profuse blood loss), anaphylactic or bacteriotoxic shock, a decrease in the amount of extracellular fluid, and many other reasons can cause conditions in which prerenal ARF develops ...
- Renal. Toxic effect on the renal parenchyma of poisonous fungi, fertilizers, uranium, mercury, cadmium and copper salts. It develops with the uncontrolled intake of antibiotics, sulfonamides, antineoplastic drugs, etc. When a large amount of hemoglobin and myoglobin circulates in the blood (due to prolonged compression of tissues during trauma, transfusion of incompatible blood, alcoholic and narcotic coma, etc.). Less common is the development of renal acute renal failure due to inflammatory kidney disease.
- Post-renal. Mechanical impairment of the outflow of urine caused by bilateral obstruction of the urinary tract stones. Less commonly, it occurs in severe injuries, extensive surgical interventions, tumors of the bladder, prostate gland, urethritis, etc.
Unexpected renal dysfunction with acute renal failure leads to pronounced metabolic disorders, in case of failure to provide timely medical care, consequences that are incompatible with life occur.
The development of acute renal failure occurs from several hours to seven days and can last twenty-four hours. If you promptly seek help from doctors, then the treatment will end with a complete restoration of the functions of both kidneys.
Kidney failure (ARF) symptoms
There are four phases of acute renal failure. At the initial stage, the patient's condition is determined by the underlying disease causing acute renal failure. There are no characteristic symptoms. Non-specific symptoms of acute renal failure - deterioration of health, loss of appetite, nausea, vomiting, diarrhea, edema of the lower and upper extremities, increased liver volume, lethargy or agitation of the patient - are masked by manifestations of the underlying disease, poisoning or injury.
At the first stage of the disease, lasting from several hours to several days, pronounced pallor of the skin, characteristic abdominal pains caused by acute intoxication are also manifested.
In the second phase (oligoanuric), there is a sharp decrease in the amount of urine excreted. During this period, the end products of metabolism accumulate in the blood, the main of which are nitrogenous toxins. Due to the termination of the kidneys' functions, acid-base balance and water-electrolyte balance are disturbed.
As a result of these processes, the following symptoms of acute renal failure occur: nausea, vomiting, loss of appetite, peripheral edema, heart rhythm disturbances and neuropsychiatric disorder.
Due to acute fluid retention in the body, edema of the brain, lungs, ascites or hydrothorax may develop.
The stage of oligoanuria lasts on average two weeks, its duration depends on the volume of kidney damage, the adequacy of the treatment and the rate of recovery of the epithelium of the renal tubules.
The third stage (restorative) is characterized by a gradual restoration of diuresis and takes place in two stages. At the first, the daily amount of urine does not exceed 400 ml (initial diuresis), then there is a gradual increase in the volume of urine - up to two liters or more. This indicates the regeneration of the glomerular function of the kidney.
The diuresis stage lasts 10-12 days. During this period, the activity of the cardiovascular and respiratory systems, digestive organs is normalized.
The fourth stage is the stage of recovery. Completely regenerate kidney function. Recovery of the body after long-term treatment can last from several months to one year or more. During this period, the volume of excreted urine, water-electrolyte and acid-base balance are normalized. In some cases, ARF can become chronic.
Diagnosis of acute renal failure (ARF)
As mentioned above, the main indicator of acute renal failure is an increase in nitrogenous compounds and potassium in the blood with a significant decrease in the amount of urine excreted by the body up to the state of anuria. The concentration ability of the kidneys and the amount of daily urine are assessed according to the results of the Zimnitsky test. Monitoring of indicators of urea, creatinine and electrolytes is of great importance. They make it possible to judge the severity of acute renal failure and the effectiveness of the treatment.
The main task in diagnosing a disease is to determine its form. For this, an ultrasound of the kidneys and bladder is performed, which allows to identify or exclude blockage of the urinary tract. In some cases, bilateral pelvic catheterization is performed. If both catheters pass freely into the pelvis, but no urine flow is observed through them, it is safe to exclude the postrenal form of ARF.
In order to determine the renal blood flow, ultrasound of the renal vessels is performed. If acute glomerulonephritis, tubular necrosis, or systemic disease is suspected, a kidney biopsy is done.
Complications of acute renal failure
The danger to the health and condition of the patient with acute renal failure lies in its complications.
Violation of water-salt metabolism. With oliguria, the risk of developing water and salt overload increases. Insufficient excretion of potassium while maintaining the level of its release from body tissues is called hyperkalemia. In patients without this disease, the potassium level is 0.3-0.5 mmol / day. The first symptoms of hyperkalemia occur at rates of 6.0-6.5 mmol / day. Muscle pain appears, ECG changes are noted, bradycardia develops, and an increased potassium content in the body can cause cardiac arrest.
In the first two stages of acute renal failure, hyperphosphatemia, hypocalcemia, and mild hypermagnesemia are observed.
Change in blood. Inhibition of erythropoiesis is a consequence of severe azotemia. In this case, the life of erythrocytes decreases, normocytic normochromic anemia develops.
Immune disorders. Infectious diseases occur in 30-70% of patients with acute renal failure due to weakened immunity. The attached infection complicates the course of the disease and often becomes the cause of the patient's death. The area of postoperative wounds becomes inflamed, the respiratory system, the oral cavity, and the urinary tract suffer. A common complication of acute renal failure is sepsis, which can be caused by both gram-positive and gram-negative flora.
Neurological disorders. In patients with acute renal failure, drowsiness and lethargy are recorded, alternating with periods of excitement, confusion of consciousness, disorientation in space are observed. Peripheral neuropathy occurs more often in elderly patients.
Complications from the cardiovascular system. With acute renal failure, arrhythmia, arterial hypertension, pericarditis, congestive heart failure can develop.
Disorders of the gastrointestinal tract. Patients with acute renal failure have abdominal discomfort, loss of appetite, nausea, and vomiting. In severe cases, uremic gastroenterocolitis develops, complicated by bleeding.
Treatment of acute renal failure (ARF)
The most important thing in the treatment of acute renal failure is the timely identification of all symptoms, elimination of the causes that provoked kidney damage.
Treatment in the initial phase. Therapy is aimed at eliminating the cause of the impaired renal function. In case of shock, it is necessary to normalize blood pressure and replenish the circulating blood volume. In case of poisoning with nephrotoxins, the patient's stomach and intestines are washed. In urology, extracorporeal hemocorrection is used, which allows you to quickly cleanse the body of toxins that have caused the development of acute renal failure. For this purpose, hemosorption and plasmapheresis are performed. In the presence of obstruction, the normal passage of urine is restored. For this purpose, stones are removed from the kidneys and ureters, the strictures of the ureters are removed, and the tumors are removed surgically.
Treatment in the phase of oliguria. The patient is prescribed furosemide and osmotic diuretics to stimulate diuresis. Dopamine is administered to reduce renal vasoconstriction. It is important to take into account the losses during sweating and breathing (400 ml) when determining the volume of injected fluid, in addition to losses during vomiting, bowel movement and urination. The patient is limited to the intake of potassium from food, he is transferred to a strict protein-free diet. Drainage of wounds and removal of areas of necrosis are performed. When choosing a dose of antibiotics, the severity of kidney damage is taken into account.
Indications for hemodialysis. Hemodialysis is performed in a patient with acute renal failure when the level of urea rises to 24 mmol / l, potassium - up to 7 mmol / l. Symptoms of uremia, acidosis and overhydration are indications for hemodialysis. Currently, to prevent complications arising from metabolic disorders, nephrologists are increasingly conducting early and prophylactic hemodialysis.
Prognosis for Acute Renal Failure
The outcome of ARF disease is influenced by the patient's age, the degree of renal dysfunction, and the presence of concomitant complications. The lethal outcome depends on the severity of the pathological condition that caused the development of acute renal failure.
If, upon detection of acute renal failure, a timely diagnosis is made, treatment is carried out correctly in stationary conditions, then the recovery of patients is guaranteed by 40%. Partial restoration of kidney function is observed in 10-15% of cases, 1-3% of patients need constant hemodialysis.
Prevention of acute renal failure
Carrying out preventive measures in order to avoid the disease of acute renal failure includes the need to completely eliminate various etiological factors. If the patient has chronic kidney disease, then after passing the examination and consulting a doctor, it is necessary to gradually reduce the dose of previously prescribed drugs.
Also, to prevent the manifestation of acute renal failure, it is necessary to undergo an X-ray contrast examination annually, a day before the procedure by introducing a hypotonic sodium solution, so that a large number of polyurias develop.
With effective prevention, timely and adequate treatment of such a disease as acute renal failure, it is possible to prevent all its serious consequences, to keep the kidney function in a normal state.
Renal failure- a pathological condition that occurs in various diseases and is characterized by a violation of all kidney functions.
The kidney is an organ of the urinary system. Its main function is the formation of urine. 
It goes like this:
- The blood entering the vessels of the kidney from the aorta reaches the glomerulus from the capillaries, surrounded by a special capsule (Shumlyansky-Bowman's capsule). Under high pressure, the liquid part of the blood (plasma) with the substances dissolved in it seeps into the capsule. This is how primary urine is formed.
- Then the primary urine moves through the convoluted tubule system. Here water and substances necessary for the body are absorbed back into the blood. Secondary urine is formed. Compared with the primary, it loses in volume and becomes more concentrated, only harmful metabolic products remain in it: creatine, urea, uric acid.
- From the tubular system, secondary urine enters the renal cups, then into the pelvis and into the ureter.
- Excretion of harmful metabolic products from the body.
- Regulation of osmotic blood pressure.
- Hormone production. For example, renin, which is involved in the regulation of blood pressure.
- Regulation of the content of various ions in the blood.
- Participation in hematopoiesis. The kidneys secrete the biologically active substance erythropoietin, which activates the formation of red blood cells (red blood cells).
The causes of kidney failure
Causes of Acute Renal Failure
Classification of acute renal failure, depending on the cause:- Prerenal... It is caused by impaired renal blood flow. The kidney is not getting enough blood. As a result, the process of urine formation is disrupted, pathological changes occur in the renal tissue. It occurs in about half (55%) of patients.
- Renal... Associated with the pathology of the renal tissue. The kidney receives enough blood, but cannot make urine. It occurs in 40% of patients.
- Post-renal... Urine forms in the kidneys, but cannot flow due to an obstruction in the urethra. If an obstacle occurs in one ureter, then the function of the affected kidney will be taken over by a healthy one - renal failure will not occur. This condition occurs in 5% of patients.
In the picture: A - prerenal renal failure; B - postrenal renal failure; C - renal renal failure.Causes of Acute Renal Failure:
| Prerenal |
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| Renal |
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| Post-renal |
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Causes of Chronic Kidney Failure
Kidney failure symptoms
Symptoms of Acute Renal Failure
Symptoms of acute renal failure depend on the stage:- initial stage;
- the stage of reducing the daily volume of urine less than 400 ml (oliguric stage);
- stage of restoration of urine volume (polyuric stage);
- full recovery stage.
| Stage | Symptoms |
| Initial | At this stage, as such, there is still no renal failure. The person is worried about the symptoms of the underlying disease. But abnormalities in the kidney tissue are already taking place. |
| Oliguric | Kidney dysfunction increases, the amount of urine decreases. Due to this, harmful metabolic products are retained in the body, and violations of the water-salt balance occur. Symptoms:
|
| Polyuric | The patient's condition is normalized, the amount of urine increases, as a rule, even more than normal. At this stage, dehydration and infections can develop. |
| Full recovery | Final restoration of kidney function. It usually lasts 6 to 12 months. If during acute renal failure most of the kidney tissue was turned off from work, then full recovery is impossible. |
Chronic kidney failure symptoms
- At the initial stage, chronic renal failure has no manifestations. The patient feels relatively normal. Usually, the first symptoms appear when 80% -90% of the kidney tissue ceases to perform its functions. But until that time, a diagnosis can be made if an examination is carried out.
- General symptoms usually appear first: lethargy, weakness, increased fatigue, frequent malaise.
- Urinary excretion is impaired. In a day, it is formed more than it should be (2-4 liters). This can lead to dehydration. Frequent urination at night is noted. In the later stages of chronic renal failure, the amount of urine decreases sharply - this is a bad sign.
- Nausea and vomiting.
- Twitching of muscles.
- Itchy skin.
- Dryness and bitterness in the mouth.
- Stomach ache.
- Diarrhea.
- Nose, stomach bleeding due to decreased blood clotting.
- Hemorrhage on the skin.
- Increased susceptibility to infections. Such patients often suffer from respiratory infections, pneumonia.
- In the late stage: the condition worsens. There are attacks of shortness of breath, bronchial asthma. The patient may lose consciousness, fall into a coma.
Diagnosis of renal failure
| Diagnostic method | Acute renal failure | Chronic renal failure |
| General urine analysis | In the general analysis of urine in acute and chronic renal failure, it is possible to identify:
 |
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| Bacteriological examination of urine | If the impaired renal function was caused by an infection, then the pathogen will be detected during the study. Also, this analysis allows you to identify an infection that has arisen against the background of renal failure, to determine the sensitivity of the pathogen to antibacterial drugs.  |
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| General blood analysis | In acute and chronic renal failure, the general blood test reveals changes:
 |
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| Blood chemistry | Helps to assess pathological changes in the body caused by impaired renal function. In a biochemical blood test in acute renal failure, changes can be detected:
| In chronic renal failure, the biochemical blood test usually reveals changes:
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| These methods allow you to examine the kidneys, their internal structure, renal cups, pelvis, ureters, bladder. In acute renal failure, CT, MRI and ultrasound are most often used to find the cause of the narrowing of the urinary tract.  |
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| Doppler ultrasound | Ultrasound examination, during which you can assess the blood flow in the vessels of the kidneys. | |
| Chest x-ray | It is used to detect disorders of the respiratory system, some diseases that can cause kidney failure.
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| Chromocystoscopy |
| |
| Kidney biopsy | The doctor receives a fragment of the kidney tissue and sends it to the laboratory for examination under a microscope. Most often, this is done using a special thick needle that the doctor inserts into the kidney through the skin. Biopsy is used in doubtful cases, when it is not possible to establish a diagnosis.
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| Electrocardiography (ECG) | This study is mandatory for all patients with acute renal failure. It helps to identify violations of the heart, arrhythmias.  |
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| Zimnitsky test | The patient collects all urine during the day in 8 containers (each for 3 hours). Determine its density and volume. The doctor can assess the state of kidney function, the ratio of daytime and nighttime urine volumes. | |
Renal failure treatment
Acute renal failure requires immediate hospitalization of the patient in a nephrological hospital. If the patient is in serious condition, he is placed in the intensive care unit. Therapy depends on the cause of the kidney dysfunction. In chronic renal failure, therapy depends on the stage. At the initial stage, the underlying disease is treated - this will help prevent severe renal dysfunction and easier cope with them later. With a decrease in the amount of urine and the appearance of signs of renal failure, it is necessary to fight pathological changes in the body. And during the recovery period, you need to eliminate the consequences.
Directions of treatment for renal failure:
| Direction of treatment | activity |
| Eliminating the causes of prerenal acute renal failure. |
|
| Eliminating the causes of renal acute renal failure |
|
| Elimination of the causes of postrenal acute renal failure | It is necessary to remove the obstacle that interferes with the outflow of urine (tumor, stone, etc.). Most often, this requires surgical intervention. |
| Eliminating the causes of chronic renal failure | Depends on the underlying disease. |
| Measures to combat disorders that occur in the body in acute renal failure |
|
| Elimination of violations of water-salt balance |
|
| Fighting blood acidification | The doctor prescribes treatment when the acidity (pH) of the blood falls below the critical value of 7.2. A solution of sodium bicarbonate is injected intravenously until its concentration in the blood rises to certain values, and the pH rises to 7.35. |
| Combating anemia | With a decrease in the level of erythrocytes and hemoglobin in the blood, the doctor prescribes blood transfusions, epoetin (a drug that is an analogue of the renal hormone erythropoietin and activates hematopoiesis). |
| Hemodialysis, peritoneal dialysis | Hemodialysis and peritoneal dialysis are methods of purifying the blood from various toxins and unwanted substances. Indications for acute renal failure:
In peritoneal dialysis, a blood purification solution is injected into the abdominal cavity. As a result of the difference in osmotic pressure, it picks up harmful substances. It is then removed from the abdomen or replaced with a new one.
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| Kidney transplant | Kidney transplantation is carried out in case of chronic renal failure, when severe disorders occur in the patient's body, and it becomes clear that it will not be possible to help the patient in other ways. The kidney is taken from a living donor or corpse. After the transplant, a course of therapy with drugs that suppress the immune system is carried out so that the donor tissue does not reject.
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Diet for acute renal failure
Prognosis for renal failure
Prognosis for Acute Renal Failure
Depending on the severity of the course of acute renal failure and the presence of complications, from 25% to 50% of patients die.The most common causes of death:
- Damage to the nervous system - uremic coma.
- Severe circulatory disorders.
- Sepsis is a generalized infection, "blood poisoning", in which all organs and systems are affected.
Prognosis for chronic renal failure
Depends on the disease, against the background of which there was a violation of kidney function, age, condition of the patient's body. Since the introduction of hemodialysis and kidney transplantation, the death rate of patients has become less frequent.Factors that worsen the course of chronic renal failure:
- arterial hypertension;
- improper diet when food contains a lot of phosphorus and protein;
- high blood protein;
- increased function of the parathyroid glands.
- kidney injury;
- an infection of the urinary system;
- dehydration.
Prevention of chronic renal failure
If the correct treatment of a disease that can lead to chronic renal failure is started in a timely manner, then renal function may not be affected or, at least, its impairment will not be so severe.Some drugs are toxic to kidney tissue and can lead to chronic kidney failure. You should not take any medications without a doctor's prescription.
Most often, renal failure develops in people with diabetes mellitus, glomerulonephritis, arterial hypertension. Such patients need to be constantly monitored by a doctor, to undergo examinations in a timely manner.
- This is a potentially reversible, sudden onset, severe impairment or cessation of renal function. Characterized by a violation of all renal functions (secretory, excretory and filtration), pronounced changes in the water-electrolyte balance, rapidly increasing azotemia. Diagnostics is carried out according to the data of clinical and biochemical analyzes of blood and urine, 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 urine output.
ICD-10
N17
General information
Acute renal failure is a suddenly developing polyetiological condition characterized by severe renal impairment and 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 of the population. Elderly people suffer 5 times more often than young and middle-aged people. In half of ARF cases, hemodialysis is required.
Causes
Prerenal (hemodynamic) acute renal failure occurs as a result of acute hemodynamic disturbances, can develop in conditions that are accompanied by a decrease in cardiac output (with pulmonary embolism, heart failure, arrhythmias, 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 form as a result of 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. It occurs when the renal parenchyma is exposed to fertilizers, poisonous fungi, salts of copper, cadmium, uranium and mercury. It develops with the uncontrolled intake of nephrotoxic drugs (anticancer drugs, a number of antibiotics and sulfonamides). X-ray contrast substances and these drugs, prescribed in the usual dosage, can cause renal acute renal failure in patients with impaired renal function.
In addition, this form of ARF is observed when a large amount of myoglobin and hemoglobin circulates in the blood (with severe macrohemaglobinuria, transfusion of incompatible blood, prolonged compression of tissues during trauma, drug and alcohol coma). Less commonly, the development of renal ARF is due to inflammatory kidney disease.
Postrenal (obstructive) ARF is formed in acute urinary tract obstruction. It is observed with a mechanical violation of the passage of urine with bilateral obturation of the ureters with stones. Less commonly, it occurs with tumors of the prostate, bladder and ureters, tuberculous lesions, urethritis and periurethritis, degenerative lesions of the retroperitoneal tissue.
In severe concomitant injuries and extensive surgical interventions, the pathology is caused by several factors (shock, sepsis, blood transfusion, treatment with nephrotoxic drugs).
ARF symptoms
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. Circulatory collapse has a very short duration, so it goes unnoticed. Non-specific 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 to be separated is less than 500 ml per day. Characterized by severe proteinuria, azotemia, hyperphosphatemia, hyperkalemia, hypernatasia, metabolic acidosis. Diarrhea, nausea, vomiting are noted. With pulmonary edema due to overhydration, shortness of breath and moist rales appear. The patient is inhibited, drowsy, may fall into a coma. Pericarditis, uremic gastroenterocolitis, complicated by bleeding often develop. The patient is susceptible to infection due to decreased immunity. Possible pancreatitis, stomatitis, mumps, 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 up to several hours or lengthened up to 6-8 weeks. Prolonged oliguria often occurs in elderly patients with concomitant vascular pathology. If the phase lasts more than a month, it is necessary to carry out differential diagnostics to exclude progressive glomerulonephritis, renal vasculitis, renal artery occlusion, diffuse necrosis of the renal cortex.
The diuretic phase lasts about two weeks. Daily urine output gradually increases and reaches 2-5 liters. There is a gradual restoration of the water-electrolyte balance. Possible hypokalemia due to significant loss of potassium in the urine. In the recovery phase, further normalization of renal functions occurs, which takes from 6 months to 1 year.
Complications
The severity of disorders characteristic of renal failure (fluid retention, azotemia, imbalance in water and electrolyte balance) depends on the state of catabolism and the presence of oliguria. With severe oliguria, there is a decrease in the level of glomerular filtration, the release of electrolytes, water and nitrogen metabolism products significantly decreases, 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 inadequate excretion of potassium while maintaining the level of its release from the tissues. In patients who do not suffer from oliguria, the level of potassium is 0.3-0.5 mmol / day. More pronounced hyperkalemia in such patients may indicate exogenous (blood transfusion, medications, the presence of potassium-rich foods 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 P-R 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. Normocytic normochromic anemia develops. Suppression of immunity contributes to the occurrence of infectious diseases in 30-70% of patients with acute renal failure. The addition of an infection aggravates the course of the disease and often becomes the cause of the patient's death. Revealed inflammation in the area of postoperative wounds, suffers from the oral cavity, respiratory system, urinary tract. A common complication of acute renal failure is sepsis.
Drowsiness, confusion, disorientation, lethargy, alternating with periods of excitement are noted. Peripheral neuropathy is more common in older patients. With acute renal failure, congestive heart failure, arrhythmia, pericarditis, and arterial hypertension may develop. Patients are worried 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 capacity of the kidneys are assessed 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 the treatment.
The main task in the diagnosis of ARF is to determine its shape. 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 pelvic catheterization is performed. If, at the same time, both catheters freely passed into the pelvis, but no urine flow is observed through them, it is safe to exclude the postrenal form of ARF. If necessary, renal blood flow is assessed by ultrasonography of the renal vessels. Suspected tubular necrosis, acute glomerulonephritis, or systemic disease is an indication for a kidney biopsy.
ARF treatment
In the initial phase, therapy is aimed primarily at eliminating the cause that caused the impaired renal function. In case of shock, it is necessary to replenish the circulating blood volume and normalize blood pressure. In case of poisoning with nephrotoxins, the patient is washed 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 have caused the development of acute renal failure. For this purpose, hemosorption is carried out and. In the presence of obstruction, the normal passage of urine is restored. To do this, they remove stones from the kidneys and ureters, promptly remove ureteral strictures and remove tumors.
In the phase of oliguria, to stimulate diuresis, the patient is prescribed furosemide and osmotic diuretics. Dopamine is administered to reduce renal vasoconstriction. When determining the volume of injected fluid, in addition to losses during urination, vomiting and bowel movement, it is necessary to take into account losses during sweating and breathing. The patient is transferred to a protein-free diet, potassium intake from food is limited. Drainage of wounds, removal of areas of necrosis is carried out. When choosing a dose of antibiotics, the severity of kidney damage should be considered.
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 overhydration. Currently, to prevent complications arising from metabolic disorders, nephrologists are increasingly conducting early and prophylactic 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 influenced by the patient's age, the degree of renal dysfunction, and the presence of complications. In surviving patients, renal functions are fully restored in 35-40% of cases, partially in 10-15% of cases. 1-3% of patients require constant hemodialysis. Prevention consists in the timely treatment of diseases and the prevention of conditions that can provoke acute renal failure.
Kidney disease is a dangerous condition that leads to a decrease in the quality of life and entails dangerous complications, up to and including death. The most common is acute renal failure.
Acute renal failure (ARF) is a disease that occurs when one or two kidneys stop functioning or decrease in performance. The disease develops rapidly, accompanied by a sharp deterioration in the patient's condition and the development of severe intoxication. According to the international classification of diseases, the diagnosis of acute renal failure is microbial 10, class N17 is assigned.
When diagnosed with acute renal failure, symptoms begin to manifest quickly enough. There are several stages of the disease, each of which has a peculiar course and is characterized by a certain condition of the patient.
Initial - lasts from 2-3 hours to 3 days. The patient experiences weakness, drowsiness, dyspeptic disorders in the form of nausea or indigestion may appear. There are no specific signs.
Oligoanuric - characterized by a sharp decrease in the volume of urine, a change in its color. A protein is present in the OAM, and the acentonic syndrome develops. The blood contains high levels of nitrogen, phosphates, sodium and potassium. Strong intoxication develops, up to a coma, and general immunity decreases.
Popiuric - a decrease in the daily volume of urine is abruptly replaced by its increase, hypotension develops, due to the leaching of useful minerals, including potassium. Arrhythmia may develop. With a favorable course and appropriate treatment, within a week the symptoms fade away, there is an improvement in the condition and blood counts.
The recovery phase - lasts up to a year, consists in the complete restoration of kidney function. Provided that preventive measures are followed, the outcome is favorable.
Depending on the causes of the disease, the following types of acute renal failure are distinguished:
Prerenal ARF - characterized by a sharp slowdown in renal blood flow. The reasons include:
- cardiovascular diseases;
- heart arrhythmia syndrome;
- blockage of the pulmonary artery;
- severe dehydration;
- cardiogenic shock.
Renal acute renal failure is characterized by a sharp release of toxic substances due to ischemic damage to the kidney tissue. Causes:
- poisoning with pesticides;
- excessive use of a number of medications, including antibiotics;
- increased content of hemoglobin in the blood;
- acute pyelonephritis and other inflammatory diseases.
Postreal ARF is caused by obstruction of the urinary tract, which is caused by:
- neoplastic diseases of internal organs;
- urethritis;
- narrowing of the pathways due to the abundance of calculi.
The causes of acute renal failure are varied. In addition to all of the above, a disease can occur due to the penetration of bacteria from other organs, therefore, even ordinary SARS can lead to the development of the disease.
Diagnosis of the disease
Since the primary signs of renal failure can be easily confused with the symptoms of other diseases, special laboratory tests and diagnostic measures should be carried out to make a diagnosis. During the examination, the doctor will collect a personal and family analysis, examine the condition of the skin, determine the presence of concomitant somatic diseases, listen to the heartbeat, and assess the state of the lymphatic system.
Further, a general urine test and a biochemical blood test are performed. There is a drop in hemoglobin, the development of leukocytosis and lymphopenia. According to biochemistry, a decrease in hematocrit is diagnosed, which indicates hyperhydration. In addition, there is an increase in the level of urea up to 6.6 mmol / l and creatinine - up to 1.45 mmol / l. An increased content of calcium, potassium, sodium, phosphate, and a decrease in acidity can be detected.
In the urine, hyaline and granular casts are found, erythrocytes and leukocytes increase, and the specific gravity is significantly reduced. An increase in the level of eosinophils in acute nephritis is possible. When diagnosed with acute renal failure, the pathogenesis depends on the causative agent of the disease and the form of the disease. To determine it, as well as to confirm or refute acute renal failure, an ultrasound examination of the kidneys and bladder is performed. There is an increase in the volume of internal organs, the presence of calculi in the pelvis and urinary tract.
For a better study, cystoscopy (examination of the bladder) and ureteroscopy (endoscopy of the urethra) are performed, as well as radionuclide research methods that allow assessing the state of internal organs by introducing a contrast agent.
In addition, a study of the heart, ECG, CT, MRI, angiography, chest X-ray (to exclude the accumulation of fluid in the pleura of the lungs), radioisotope scanning of the kidneys are carried out. In severe cases, biopsy and bilateral pelvic catheterization may be recommended.
Treatment features
When diagnosed with acute renal failure, treatment is prescribed immediately. The drugs prescribed for the disease are determined by the type and stage of the disease.
In the initial stage of acute renal failure, treatment of a concomitant disease that caused renal dysfunction is taken as the basis. In the case of cardiogenic shock, therapy is prescribed aimed at normalizing cardiac activity, eliminating arrhythmias and restoring blood flow. In case of chemical or food poisoning, they relieve acute intoxication syndromes. If there are stones in the pelvis, they are cleaned, and methods are also used to get rid of stones. In the event that the clinic of the disease obliges, anticancer therapy is prescribed.
If the disease is diagnosed at the stage of oliguria, the patient is prescribed diuretics, in particular furasimide, mannitol, a 20% glucose and insulin solution. To prevent dehydration of the body, dopamine is injected intravenously to the patient, as well as other drugs that restore the electrolyte balance of the blood. For severe inflammatory processes, antibiotics are prescribed. All treatment is carried out exclusively in a hospital to prevent the development of complications and the occurrence of side effects. Also, the patient is advised to lead a healthy lifestyle and follow a special diet with low protein and salt content.
If the clinic of the disease is characterized by manifestations of dangerous symptoms, surgical intervention or connection to the hemodialysis system is recommended. The latter is used in case of persistent developed intoxication of the body, if the level of urea in the tests rises to 24 mmol / l, and potassium is diagnosed at 7 mmol / l. In addition, the dialysis procedure is prescribed with the ineffectiveness of conservative therapy, the serious condition of the patient, and the state of chronic ketocidosis.
Features of the course of the disease in children
Acute renal failure in children is a rather rare disease, but very dangerous. Not so long ago, it had very negative consequences, including death. The disease manifests itself as a sudden deterioration in well-being, electrolyte imbalance, severe intoxication and headache and is characterized by hypoxia of the renal tissues, as well as damage to the tubules.
Acute renal failure develops in children against the background of diseases such as:
- nephritis;
- infectious diseases of the urinary system;
- toxic shock;
- intrauterine infections and hypoxia;
- hemoglobin and myoglobinuria;
- renal ischemia.
Also, a predisposition to the onset of the disease can be banal hypothermia, suffocation, respiratory failure, asphyxia - in newborns. In young patients, two forms of the disease are distinguished: functional and organic.
Functional acute renal failure in children occurs against the background of dehydration and impaired blood flow through the vessels. This form of the disease is poorly diagnosed, however, it is reversible. The organic form of the disease poses a great danger. The disease, manifested by lethargy, pallor and dryness of the skin, has pronounced symptoms.
There is a low amount of urine, nausea, dizziness, vomiting and tachycardia may occur, often developing acetone syndrome, manifested by indomitable vomiting and severe dehydration. In especially severe cases, moist rales are heard in the lungs, there is a risk of developing a uremic coma.
If at least one of the symptoms appears, the child needs to be hospitalized immediately. Emergency care for acute renal failure will be provided immediately. It includes measures to restore electrolyte balance, compensate for fluid in the body. Also, therapy is prescribed for the underlying disease that caused the problem in the kidneys.
The rest of the therapeutic measures in children are no different from adults. It is important to heal the disease to the end, and not to let everything take its course after the disappearance of the main symptoms. On average, treatment of severe forms in young patients lasts 3-6 months. If the kidneys are not fully restored, a chronic form of the disease may develop.
Chronic renal failure
If the acute form of the disease could not be cured completely, removing all possible causes, and kidney dysfunction is observed for 3 months or more, the chronic form of the disease develops. Its symptoms slowly increase, ranging from excessive weakness and rapid fatigue of the patient and ending with the development of cardiac asthma and pulmonary edema. Other symptoms of chronic kidney disease include:
- dryness and bitterness in the mouth;
- frequent seizures;
- loss of appetite;
- lower back pain;
- frequent headaches and pressure drops.
During the illness, internal bleeding may develop, the body's resistance to various infections may decrease, frequent dizziness is possible, up to loss of consciousness. The reasons provoking chronic renal failure include diabetes mellitus, various infectious diseases, diseases of the cardiovascular system, chronic glomerulonephritis, urolithiasis, polycystic kidney disease, poisoning with toxic products.
Acute and chronic renal failure is diagnosed in the same way, with the proviso that in the chronic form of the disease, the indicators may not be so overestimated, but last for a longer time. The treatment is also similar. If the disease develops rapidly, the doctor may recommend removal of the malfunctioning kidney or hemodialysis and peritoneal dialysis procedures.
The difference between the latter is that during hemodialysis, blood plasma is periodically filtered through an "artificial kidney" apparatus in order to purify the blood and remove toxins, while in peritoneal dialysis, cleaning occurs directly through the patient's peritoneum using a special catheter that conducts dialysis solution into the patient's blood.
Diet for renal failure
Treatment of any form of renal failure is impossible without adherence to a special diet. Since the disease is associated with impaired renal function, the diet in acute renal failure is characterized by a decrease in protein (up to 50 grams per day), salt, and the consumption of fatty, spicy, fried foods should also be limited.
Food has a high calorie content, rich in healthy fats and carbohydrates. You should not neglect fresh vegetables and fruits, use berry fruit drinks, juices and compotes, it is also recommended to include whole grain bread in the diet, as well as baked goods based on corn and rice flour.
The basis of the diet is taken from cereals, soups, vegetable stews, low-fat broths, the use of legumes, nuts, dried fruits is permissible. In limited quantities, it is possible to eat fatty fish, caviar, dairy products, seeds, eggs.
- drinks containing caffeine;
- chocolate;
- rich bone and meat broths;
- alcoholic drinks;
- hot spices;
- smoked and canned foods;
- mushrooms.
Otherwise, nutrition for acute and chronic renal failure should be selected for each patient individually. It should be noted that during periods of exacerbation, the diet should be tightened, salt should be completely removed, the amount of proteins should be reduced to 20 grams per day, and the use of animal proteins is more likely to be acceptable than plant proteins. That is why in the acute form of the disease one should not lean on beans, various nuts and dried fruits. However, food should be enjoyable, so it's worth experimenting with recipes to get delicious meals from the ingredients available.
Complications of kidney failure
Complications in acute and chronic renal failure develop in the absence of timely treatment and failure to follow the recommendations of a specialist.
In the case of an acute form, the level of risk depends on the degree of the disease, the state of catabolism, the presence of oliguria and nephrotic syndrome. In this case, there is a risk of serious poisoning with metabolic products and minerals, the concentration of which in the blood is steadily increasing. Hyperkalemia develops without proper attention in acute renal failure. Having reached critical values, this condition can lead to serious heart problems, up to and including death.
Diseases can cause severe changes in the blood, provoking anemia or causing immune disorders. Patients with a chronic form of the disease must be extremely careful and avoid contact with unhealthy people. Their body, more than others, is susceptible to infection, which can rapidly develop and lead to the death of the patient.
It is also possible to develop neurological diseases and the occurrence of acute heart failure. In severe cases of acute renal failure, gastroenterocolitis develops, causing intestinal bleeding, which further complicates the patient's condition.
In the case of a chronic form of the disease, there is an active leaching of calcium from the body, which leads to increased fragility of bones. From the side of neurology, frequent seizures, complete or partial loss of consciousness, and mental retardation may appear. Pregnant women with chronic renal failure require special attention. The development of the disease or the occurrence of an exacerbation can lead to abortion and a threat to the mother's life.
Disease prevention
If the symptoms of the acute form of the disease are arrested or the period of exacerbation in chronic patients is removed, the patient should take a whole range of measures so that the disease does not return soon or even recedes altogether:
- Follow a strict diet. Even if there has been a steady improvement, you should not lean on protein foods. And, if the patient still allows himself meat, then let it be boiled or baked, well, in no case smoked or spicy.
- Give up alcohol or reduce its consumption.
- Limit your intake of caffeinated beverages.
- Maintain weight. If the condition allows, you should go in for sports or, at least, walk more in the fresh air.
- Carefully follow all the recommendations of the attending physician, take all medications prescribed for treatment without omissions.
- Quit smoking.
- Avoid being in smoky rooms, working with pesticides.
- Reduce the risk of any exposure to toxins from the outside.
- In the event of foci of inflammation in any area of the body, immediately stop them in order to avoid the spread of infection.
Acute renal failure is a dangerous disease leading to serious malfunctions of the body, up to and including death. No one is immune from the disease. But it is possible to get rid of complications. The main thing is to turn to a narrow specialist in time and follow all the recommendations not only in the stage of exacerbation, but also throughout the entire period of rehabilitation.
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