Acute renal failure - a potentially reversible, sudden onset pronounced impairment or cessation of renal function. Characterized by a violation of all renal functions (secretory, excretory and filtration), pronounced changes in water and electrolyte balance, rapidly increasing azotemia. In the development of acute renal failure, there are 4 consecutive phases: initial, oligoanuric, diuretic, and recovery period. 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. It includes symptomatic therapy, methods of extracorporal hemocorrection, maintaining optimal blood pressure and diuresis.
Etiology of prerenal ARF
Prerenal acute renal failure may 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 cirrhosis of the liver). May occur as a result of severe vasodilation caused by bacteric toxic or anaphylactic shock.
Etiology of renal arrester
Occurs with toxic effects on the renal parenchyma of 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-raystatic substances and the listed drugs, prescribed in the usual dosage, can cause renal ARF in patients with impaired renal function.
In addition, this form of OPN occurs when a large amount of myoglobin and hemoglobin circulate in the blood (in case of severe macrohemaglobinuria, incompatible blood transfusion, prolonged compression of tissues during trauma, drug and alcohol coma). Less commonly, the development of renal acute renal failure is due to inflammatory kidney disease.
Etiology of postrenal acute renal failure
It develops when a mechanical violation of the passage of urine occurs with bilateral obstruction of the urinary tract by stones. Rarely occurs in tumors of the prostate gland, bladder and ureter, tuberculous lesions, urethritis and periourethritis, dystrophic lesions of retroperitoneal tissue.
In severe combined injuries and extensive surgical interventions, acute renal failure is caused by several factors (shock, sepsis, blood transfusion, treatment with nephrotoxic drugs).
Symptoms of OPN
Four phases of acute renal failure are distinguished:
The patient’s condition is determined by the underlying disease causing the acute renal failure. Clinically, the initial phase is usually not detected due to the lack of characteristic symptoms. Circulatory collapse that occurs in this phase has a very short duration, and therefore goes unnoticed. Nonspecific symptoms of acute renal failure (drowsiness, nausea, lack of appetite, weakness) are masked by the manifestations of the underlying disease, injury or poisoning.
Anuria occurs rarely. The amount of urine discharge is less than 500 ml per day. Characterized by pronounced proteinuria, azotemia, hyperphosphatemia, hyperkalemia, hypertension, metabolic acidosis. There is diarrhea, nausea, vomiting. When pulmonary edema due to overhydration appears shortness of breath and moist rales. The patient is inhibited, drowsy, may fall into a coma. Often develops pericarditis, uremic gastroenterocolitis, complicated by bleeding. The patient is susceptible to infection due to decreased immunity. Possible pancreatitis, parotitis stomatitis, pneumonia, sepsis.
The oligoanuric phase of acute renal failure develops during the first three days after exposure. The late development of the oligoanuric phase is considered a prognostic unfavorable sign. The average duration of this stage is 10-14 days. The period of oliguria can be shortened to several hours or lengthen to 6-8 weeks. Prolonged oliguria occurs more often in elderly patients with concomitant vascular pathology. When the oliguric stage of acute renal failure last more than a month, it is necessary to conduct additional differential diagnostics to exclude progressive glomerulonephritis, renal vasculitis, occlusion of the renal artery, 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 recovery of water and electrolyte balance. Possible hypokalemia due to significant loss of potassium in the urine.
There is a further restoration of renal function, which takes from 6 months to 1 year.
Complications of OPN
The severity of disorders characteristic of renal failure (fluid retention, azotemia, disruption of water and electrolyte balance) depends on the state of catabolism and the presence of oliguria. In severe oliguria, there is a decrease in the glomerular filtration level, the release of electrolytes, water and nitrogen metabolism products is significantly reduced, which leads to more pronounced changes in the blood composition.
When oliguria increases the risk of water and salt overload. Hyperkalemia in acute renal failure is caused by insufficient excretion of potassium while maintaining its release from the tissues. In patients not suffering from oliguria, the level of potassium is 0.3-0.5 mmol / day. More pronounced hyperkalemia in these 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 level of potassium exceeds 6.0-6.5 mmol / l. Patients complain of muscle weakness. In some cases, develop lethargic tetraparesis. ECG changes are noted. The amplitude of the P teeth decreases, the P-R interval increases, and bradycardia develops. A significant increase in potassium concentration can cause cardiac arrest.
At the first two stages of acute renal failure, hypocalcemia, hyperphosphatemia, mild hypermagnemia are observed.
The consequence of severe azotemia is the inhibition of erythropoiesis. The life span of red blood cells is reduced. Normocytic normochromic anemia develops.
Inhibition of immunity contributes to the occurrence of infectious diseases in 30-70% of patients with acute renal failure. The accession of the infection makes the course of the disease worse and often causes the death of the patient. Inflammation develops in the area of postoperative wounds, the oral cavity, the respiratory system, and urinary tract suffer. A frequent complication of acute renal failure is sepsis, which can be caused by both gram-positive and gram-negative flora.
Drowsiness, confusion, disorientation, lethargy, alternating with periods of arousal. Peripheral neuropathy is more common in older patients.
- Complications of the cardiovascular system
With acute renal failure, congestive heart failure, arrhythmia, pericarditis, arterial hypertension can develop.
Patients are worried about abdominal discomfort, nausea, vomiting, loss of appetite. In severe cases, uremic gastroenterocolitis develops, often complicated by bleeding.
Diagnosis of arrester
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 is estimated according to the results of the Zimnitsky test. The monitoring of such indicators of blood biochemistry as urea, creatinine and electrolytes is important. It is these indicators that make it possible to judge the severity of acute renal failure and the effectiveness of therapeutic measures.
The main task in the diagnosis of acute renal failure is to determine its shape. For this, an ultrasound of the kidneys and bladder is carried out, which allows to identify or eliminate urinary tract obstruction. In some cases, bilateral catheterization of the pelvis is performed. If at the same time both catheters freely passed into the pelvis, but urine excretion through them is not observed, it is safe to exclude the postrenal form of acute renal failure.
If necessary, to assess the renal blood flow spend USDG vessels of the kidneys. Suspected tubular necrosis, acute glomerulonephritis, or systemic disease is an indication for a biopsy of the kidney.
Treatment in the initial phase
Therapy is primarily aimed at eliminating the cause of the renal dysfunction. In case of shock, it is necessary to replenish the volume of circulating blood and normalize blood pressure. In case of poisoning by nephrotoxicity, patients are washed in the stomach and intestines. The use of modern treatment methods in urology such as extracorporeal hemocorrection allows you to quickly cleanse the body of toxins that have become the cause of the development of acute renal failure. For this purpose, hemosorption and plasmapheresis are performed. In the presence of obstruction restore normal passage of urine. To do this, carry out the removal of stones from the kidneys and ureters, the rapid removal of ureteral strictures and the removal of tumors.
Treatment in the phase of oliguria
To stimulate diuresis, furosemide and osmotic diuretics are prescribed to the patient. Dopamine is administered to reduce vasoconstriction of the renal vessels. When determining the volume of fluid injected, in addition to losses during urination, vomiting and emptying of the intestines, it is necessary to take into account losses due to sweating and respiration. The patient is transferred to a protein-free diet, limit the intake of potassium from food. Wound drainage, removal of areas of necrosis. When choosing a dose of antibiotics should take into account the severity of kidney damage.
Indications for hemodialysis
Hemodialysis is carried out with an increase in the level of urea to 24 mmol / l, potassium - up to 7 mmol / l. Indications for hemodialysis are the symptoms of uremia, acidosis and overhydration. Currently, to prevent complications arising from metabolic disorders, nephrologists are increasingly conducting early and prophylactic hemodialysis.
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 patient's age, the degree of renal dysfunction, and the presence of complications. In surviving patients, the renal functions are fully restored in 35-40% of cases, and partially in 10-15% of cases. 1-3% of patients require constant hemodialysis.
Characteristic of the disease
Acute renal failure (ARF) is a syndrome of rapid and sudden dysfunction. As a result, a significant increase in urea is noted, creatinine increases, and a gradual accumulation of protein metabolism in the body is also characteristic.
The International Classification of Diseases (ICD-10) includes several types of acute renal failure:
- with tubular necrosis,
- with acute cortical necrosis,
- with medullary necrosis,
- another arrester,
Find out what kind of syndrome according to ICD-10 (classification of the 10th revision) can only be a specialist.
Most often, the changes caused by the disease are reversible, and after a while you can resume normal kidney function. This can be done in the event that the damaging actions have left a not too large-scale impact. Full restoration of all functions occurs at least in a year.
Forms of renal failure
The causes and symptoms of the disease will depend not only on its form, but also on how quickly it develops. Experts identify three main forms of acute renal failure: prerenal, renal and postrenal.
Causes of prerenal insufficiency - acute circulatory disorders in the kidneys. Pathogenesis develops due to certain disruptions of the body, which reveals this syndrome:
- heart failure
- heart palpitations
- cardiac tamponade,
- frequent or too much dehydration,
- accumulations of "unnecessary" fluid in the abdominal cavity,
- anaphylactic shock,
- artery blockage.
The pathogenesis of this form is in renal tissue damage, ischemic, inflammatory or toxic. Symptoms in this case may be blurred. The disease is a consequence of a number of disorders that are affected by certain causes. Syndrome is manifested due to:
- exposure to poisons, salts, metals or fertilizers,
- drugs in the "wrong" dosage,
- if the treatment was carried out with potentially dangerous medications,
- there was a high content of myoglobin in the blood,
- serious inflammatory diseases of the kidneys.
Stages and symptoms
Symptoms of the manifestation of acute renal failure in a very small extent depend on the factor that accompanies the onset of the disease. The pathogenesis of the disease will be based on its stage and what causes have become a provocateur. A certain classification is used: initial, oligoanuric, polyuric, and recovery period.
Stage II (oligoanuric)
The first signs of the second stage are a sharp decrease in the amount of urine that is released daily (oliguria). The obvious criterion is a reduction in daily fluid excretion to 300-500 ml. If anuria has already occurred, the volume may not exceed 50 ml. For correct diagnosis, these data are of particular importance.
It is in the second stage that the syndrome manifests itself most clearly: metabolic products begin to accumulate, a significant number of them are waste of nitrogenous slags. The kidneys gradually begin to work worse and worse, the result - the acid-base balance in the body is disturbed, the water-electrolyte balance is lost, the process of acidification of the blood, anuria starts. Creatinine can exceed the baseline by 50%.
Acute renal failure at this stage presents the following symptoms:
- peripheral puffiness,
- frequent nausea
- complete loss of appetite
- developing heart rhythm disorder,
- confused consciousness.
Outcomes may not be the most pleasant: due to constant delays in fluids, pulmonary or brain edema, ascites, and hydrothorax develop quickly and quickly. The criterion of urine retention is long, anuria can last about 10-14 days. The disease is actively developing, so it is the most dangerous. If anuria begins or creatinine is too elevated, the patient needs emergency care and urgent treatment.
Stage III (polyuric)
This stage is characterized by a significant increase in fluid, diuresis is gradually restored. The obvious criterion for the polyuric stage is that creatinine gradually returns to normal. Pathogenesis has two phases. The first is the initial diuresis, when the daily amount of urine is a maximum of 400 ml.
Every day the volume of fluid will increase. In the type of polyuria phase, the body releases at least two liters of urine per day. This number is a symptom of the resumption of glomerular kidney function. Pathological changes clinic saves.
Urine at the polyuric stage has a low density, high erythrocyte and protein levels are observed in sediments. Potassium content in the blood gradually comes to normal, the products of nitrogen metabolism and excess creatinine are destroyed. Treatment is required.
The stage of polyuria lasts 10-15 days, at this time you need to monitor all signs of the disease.
Stage IV (recovery period)
The obvious criterion of recovery is the restoration of the volume of normal discharge of urine. Balances of the body (water-electrolyte and acid-base) and creatinine return to normal. If the correct treatment was chosen, recovery will take 10-15 months. In the absence of the necessary assistance, acute renal failure becomes chronic, the syndrome will have to be treated throughout life.
For correct and high-quality diagnosis, it is necessary to analyze the data of the laboratory and instrumental examination and the general clinical picture, without this, the correct treatment is impossible. Syndrome of acute renal failure can be cured in the event that the main causes of the disease are identified. In the future, the prevention of the disease will be necessary.
Required instrumental studies
To make a precise definition of the disease, it is necessary to identify signs of changes in the size of the kidneys, to exclude the possibility of accumulation of fluids in the pleural cavity. In order to identify the signs of the disease must be carried out must:
- tomography of two types: magnetic resonance and computer,
- angiography: problems need to be ruled out, such as renal artery stenosis, ascending thrombosis, aneurysm,
- Abdominal ultrasound,
- Ultrasound of the kidney,
- chest x-ray,
- kidney scan using a radioisotope.
An additional requirement is sometimes a biopsy. If the clinic is confirmed, the patient needs urgent help.
Required laboratory tests
For the diagnosis it is necessary to exclude acute inflammatory diseases, analyze creatinine and urea. Make sure that the disease does not develop. The clinic takes into account hyperkalemia, hyperphosphatemia, hypocalcemia (serum concentration - more than 10 mg) and a number of other data.
To identify the signs, you will need:
- bacteriological and general urine test,
- biochemical and general blood tests.
Types of treatment needed
With such a serious illness, the patient needs emergency care. The criterion of therapy for the most part depends on the stage of the underlying disease. If any symptoms of the disease appear, it is necessary to contact the local therapist. After the visit you will need a nephrologist and a urologist.
Concluded emergency assistance in the rapid elimination of causal factors. If necessary, the patient's body is removed from the shock, restore the amount of urine. A necessary criterion in the case of poisoning is an urgent detoxification.
If a diagnosis such as acute renal failure is made, antibiotics and other drugs are administered in a reduced dosage: most of them are eliminated from the body precisely because of the functionality of the kidneys.
Medication consists of taking a number of medicines. Required:
- salt solutions,
- infusion therapy drugs,
- means for the expansion of blood vessels
- medicines for raising blood pressure.
Emergency care and drug treatment are carried out exclusively under the supervision of a physician, regardless of what causes the disease and how it develops. Self-medication is not allowed and may be life-threatening to the patient.
Causes of acute renal failure
1. Shock kidney. Acute renal failure develops in traumatic shock with massive tissue damage due to a decrease in circulating blood volume (blood loss, burns), and reflex shock. This is observed in case of accidents and injuries, heavy operations, with damage and disintegration of the tissues of the liver and pancreas, myocardial infarction, burns, frostbite, incompatible blood transfusions, abortions.
2. Toxic kidney. OPN occurs when poisoning with nephrotropic poisons such as mercury, arsenic, bertoletova salt, snake venom, insect venom, fungi. Intoxication with drugs (sulfonamides, antibiotics, analgesics), radiopaque substances. Alcoholism, drug addiction, substance abuse, professional contact with heavy metal salts, ionizing radiation.
3. Acute infectious kidney. Develops with infectious diseases: leptospirosis, hemorrhagic fever. Occurs in severe infectious diseases, accompanied by dehydration (dysentery, cholera), and bacterial shock.
4. Obstruction (obstruction) of the urinary tract. Occurs with tumors, stones, compression, trauma to the ureter, with thrombosis and embolism of the renal arteries.
5. It develops with acute pyelonephritis (inflammation of the renal pelvis) and acute glomerulonephritis (inflammation of the renal glomeruli).
Symptoms of acute renal failure
In the initial period, the symptoms of the disease that led to the development of acute renal failure come to the fore. These are symptoms of poisoning, shock, the disease itself. At the same time, the amount of urine excreted (diuresis) initially begins to decrease to 400 ml per day (oliguria), and then to 50 ml per day (anuria). Nausea, vomiting, decreased appetite. There is a drowsiness, a retardation of consciousness, convulsions, hallucinations may appear. The skin becomes dry, pale with hemorrhages, edema appears. Breathing is deep, frequent. Tachycardia, heart rhythm disturbance, arterial pressure is heard. Abdominal distention, liquid stool is characteristic.
With timely treatment, a period of diuresis recovery begins. The amount of urine excreted increases to 3-5 liters per day. All symptoms of acute renal failure gradually disappear. For complete recovery from 6 months to 2 years.
Treatment of acute renal failure
All patients with acute renal failure require urgent hospitalization in the nephrology and dialysis department or in the intensive care unit.
The treatment of the underlying disease, the elimination of the factors that caused kidney damage, is of the utmost importance as soon as possible. Since in most cases the cause is shock, it is necessary to start anti-shock measures as soon as possible. In case of massive blood loss, blood loss is compensated by the introduction of blood substitutes. In case of poisoning, toxic substances are removed from the body by washing the stomach, intestines, the use of antidotes. In severe renal failure, hemodialysis or peritoneal dialysis sessions are performed.
Stages of treatment of patients with acute renal failure:
- Eliminate all causes of reduced renal function, susceptible to specific therapy, including correction of pre-renal and post-renal factors,
- Try to achieve a steady amount of urine output,
- Conservative therapy:
- reduce the quantities of nitrogen, water and electrolytes entering the body to such an extent that they correspond to their output amounts,
- provide adequate nutrition to the patient
- change the nature of drug therapy,
- to monitor the clinical condition of the patient (the frequency of measurements of vital indicators is determined by the patient's condition, measurement of quantities entering the body and substances released from it, body weight, examination of wounds and intravenous infusion sites, physical examination should be carried out daily),
- to ensure control of biochemical parameters (the frequency of determining the concentrations of AMK, creatinine, electrolytes and counting blood formula will be dictated by the patient's condition, in patients suffering from oliguria and catabolism, these indicators should be determined daily, the concentration of phosphorus, magnesium and uric acid - less often)
4. Perform dialysis therapy
A number of manifestations of acute renal failure can be controlled using conservative therapy. After any violations of the volume of the intravascular fluid are eliminated, the amount of fluid entering the body should correspond exactly to the sum of its measured output amount and imperceptible losses. The amount of sodium and potassium injected into the body should not exceed their measured output quantities. Daily monitoring of fluid balance and body weight makes it possible to establish whether the patient has a normal amount of intravascular fluid. In patients with acute renal failure, receiving adequate treatment, body weight is reduced by 0.2-0.3 kg / day. A more significant decrease in body weight suggests hypercatabolism or a decrease in the volume of intravascular fluid, and a less significant one suggests that excessive amounts of sodium and water enter the body. Since most drugs are excreted from the body, at least partially, by the kidneys, ptalnoe attention should be paid to the use of drugs and their dosage. The concentration of sodium in the serum serves as a guide to determine the required amount of injected water. A decrease in sodium concentration indicates that there is an excess of water in the body, while an unusually high concentration indicates a lack of water in the body.
In order to reduce catabolism, it is necessary to ensure daily intake of at least 100 g of carbohydrates in the body. Some of the recent studies state that the introduction of a mixture of amino acids and hypertonic glucose solution into central veins improves the condition of patients and decreases mortality in a group of patients suffering from acute renal failure developed after surgery or injury. Since the parenteral administration of excessively large amounts of nutrients can be associated with significant difficulties, this type of food should be reserved for patients who are prone to catabolism and who cannot obtain satisfactory results with the usual administration of nutrients through the mouth. Previously, anabolic androgens were used to reduce the level of protein catabolism and reduce the rate of increase in AMK. Currently, this treatment is not used. Additional measures that reduce the level of catabolism include the timely removal of necrotic tissue, the control of hyperthermia, and the early onset of specific antimicrobial therapy.
Patients with a weak degree of metabolic acidosis associated with acute renal failure, treatment is not prescribed, except for those whose bicarbonate concentration in the blood serum does not decrease less than 10 meq / l. An attempt to restore the acid-base state by the urgent introduction of alkalis can reduce the concentration of ionized calcium and provoke the development of tetany. Hypocalcemia usually is asymptomatic and rarely requires specific correction. Hyperphosphatemia should be controlled by oral administration of 30–60 ml of aluminum hydroxide 4–6 times a day, since when the amount of calcium x phosphorus is more than 70, soft tissue calcification develops. Early initiation of dialysis therapy will help control the elevated serum phosphorus concentration in patients with severe hyperphosphatemia. If the patient did not reveal acute nephropathy due to uric acid, then secondary hyperuricemia in acute renal failure most often does not require the use of allopurinol. The decrease in the glomerular filtration rate makes the fraction of filtered uric acid and, therefore, the deposition of uric acid inside the tubules insignificant. In addition, for unknown reasons, acute renal failure, despite hyperuricemia, is rarely complicated by clinically manifested gout. For timely detection of gastrointestinal bleeding, it is important to carefully monitor changes in the hematocrit and the presence of hidden blood in the feces. If the hematocrit number decreases rapidly and the rate of this decrease turns out to be inadequate severity of renal failure, then alternative causes of anemia should be sought.
Congestive heart failure and hypertension are indicators of the presence of excess fluid in the body and require the adoption of appropriate measures. It should be remembered that many drugs, such as digoxin, are mainly excreted by the kidneys. As noted earlier, persistent hypertension is not always caused by an increased volume of fluid in the body, and factors such as hyperreninemia may contribute to its development. In some cases, in order to prevent gastrointestinal bleeding, some seriously ill patients successfully conducted a selective blockade of histamine-2 receptors (cimetidine, ranitidine), but the feasibility of such treatment in acute renal failure has not yet been studied. To avoid infection and disruption of the anatomical barriers, prolonged bladder catheterization should be avoided, oral and skin reorganization, intravenous injection catheters should be made and the skin incision should be treated to perform a tracheostomy, as well as careful clinical observation should be carried out. With an increase in body temperature in a patient, it is necessary to carefully examine him, paying particular attention to the condition of the lungs, urinary tract, wounds and places of introduction of a catheter for intravenous infusion.
In acute renal failure, hyperkalemia often develops. If the increase in serum potassium concentration is small (less than 6.0 mmol / l), then to correct it, it is enough to exclude all sources of potassium from the diet and keep constant careful laboratory monitoring of biochemical parameters. If the concentration of potassium in the blood serum increases to levels in excess of 6.5 mmol /, and especially if there are any changes on the ECG, then the patient should be actively treated. Treatment can be divided into emergency and routine forms. Emergency treatment includes intravenous calcium (5-10 ml of 10% calcium chloride solution is administered intravenously for 2 minutes under ECG control), bicarbonate (44 meq in 5 minutes) and glucose with insulin (200–300 ml 20 % glucose solution containing 20-30 U of normal insulin, administered intravenously over 30 minutes). Routine treatment involves the introduction of potassium-binding ion exchange resins, such as polystyrene sodium sulfonate. They can be administered orally every 2-3 hours per dose. 25-50 g with 100 ml of 20% sorbitol for the prevention of constipation. On the other hand, a patient who cannot take medicine by mouth can be administered at intervals of 1–2 h 50 g of sodium polystyrene sulfonate and 50 g of sorbitol in 200 ml of water by means of a retention enema. If refractory hyperkalemia develops, hemodialysis may be necessary.
Some patients with acute renal failure, especially in the absence of their oliguria and catabolism, can be successfully treated without dialysis or with minimal use. There is an increasing tendency to use dialysis therapy in the early stages of acute renal failure to prevent possible complications. Early (prophylactic) dialysis often simplifies patient management, creating the possibility of a more liberal approach to ensuring that adequate amounts of potassium and fluids enter the body and allowing the patient to improve overall well-being. The absolute indications for dialysis are symptomatic uremia (usually manifested by symptoms of the central nervous system and / or the gastrointestinal tract), the development of resistant hyperkalemia, severe acidemia, or the accumulation in the body of excess fluid that is not amenable to medication, and pericarditis. In addition, many medical centers try to maintain predialysis levels of BUN and serum creatinine, respectively, less than 1000 and 80 mg / l. In order to ensure adequate prevention of uremic symptoms in patients without oliguria and catabolism, dialysis may be required only in rare cases, and patients whose condition is aggravated by catabolism and injuries may require daily dialysis. Often, peritoneal dialysis is an acceptable alternative to hemodialysis. Peritoneal dialysis may be especially useful for patients with non-catabolic renal failure, who is shown infrequent dialysis. To control the volume of extracellular fluid in patients with acute renal failure, you can use slow continuous blood filtration using highly permeable filters. Currently available filters, connected to the circulatory system through an arteriovenous shunt, can output from 5 to 12 liters of plasma ultrafiltrate per day without using a pump. Therefore, such devices seem to be particularly useful for the treatment of patients suffering from oliguria and with an increased volume of extravascular fluid and unstable hemodynamics.
The nutrition of such patients is very important.
Complications of acute renal failure
In the initiating and supporting phases of acute renal failure, the excretion of the products of nitrogen metabolism, water, electrolytes and acids from the body with urine is disturbed. The severity of changes that occur in the chemical composition of the blood depends on the presence of oliguria, the state of catabolism in the patient. In non-oligurian patients, higher levels of glomerular filtration are noted than in patients with oliguria, and as a result, more of the products of nitrogen metabolism, water, and electrolytes are excreted in the urine. Therefore, violations of the chemical composition of the blood in acute renal failure in patients not suffering from oliguria are usually less pronounced than in patients with oliguria.
Patients suffering from acute renal failure, accompanied by oliguria, are at high risk of developing salt and water overload, leading to hyponatremia, edema, and stagnation of blood in the lungs. Hyponatremia is a consequence of the ingestion of excessive amounts of water, and edema - excessive amounts of both water and sodium.
Hyperkalemia is characteristic of acute renal failure, due to reduced elimination of potassium by the kidneys with continued release of it from the tissues. The usual daily increase in serum potassium concentration in non-oligurian patients and subject to catabolism is 0.3-0.5 mmol / day. A larger daily increase in serum potassium concentration indicates a possible endogenous (tissue destruction, hemolysis) or exogenous (drugs, food ration, blood transfusion) potassium load, or potassium release from cells due to acidemia. Hyperkalemia is usually asymptomatic as long as the serum potassium concentration does not rise to values in excess of 6.0-6.5 mmol / l. If this level is exceeded, changes on the electrocardiogram are observed (bradycardia, deviation of the electrical axis of the heart to the left, pointed teeth T, expansion of ventricular complexes, an increase in an interval of P - R and decrease in amplitude of teeth P) and finally cardiac arrest can occur. Hyperkalemia can also lead to the development of muscle weakness and sluggish tetraparesis.
In acute renal failure, hyperphosphatemia, hypocalcemia and a low degree of hypermagnemia are also observed.
Soon after the development of significant azotemia, normocytic, normochromic anemia develops, and the hematocrit number stabilizes at a level of 20-30 percent by volume. Anemia is caused by a weakening of erythropoiesis, as well as a slight decrease in the life span of red blood cells.
Infectious diseases complicate the course of acute renal failure in 30-70% of patients and are considered as the leading cause of death. Gates of infection often serve as the airways, surgical sites and urinary tract. At the same time, septicemia often occurs, caused by both gram-positive and gram-negative microorganisms.
Cardiovascular complications of acute renal failure include circulatory failure, hypertension, arrhythmias, and pericarditis.
Acute renal failure is often accompanied by neurological disorders. In patients who are not on dialysis, there are lethargy, drowsiness, clouding of consciousness, disorientation, fluttering tremor, anxiety, myoclonic muscle twitching and seizures. To a greater extent they are characteristic of elderly patients and are amenable to correction during dialysis therapy.
Acute renal failure is often accompanied by complications of the gastrointestinal tract, including anorexia, nausea, vomiting, intestinal obstruction and vague complaints of abdominal discomfort.
Prevention of renal failure.
Preventive treatment deserves special attention because of the high rates of morbidity and mortality among patients with acute renal failure. During the Vietnam War, among the military personnel, there was a fivefold decrease in mortality rates caused by acute renal failure, compared with similar indicators that occurred during the Korean War. Such a decrease in mortality occurred in parallel with the provision of an earlier evacuation of the wounded from the battlefield and an earlier increase in the volume of intravascular fluid. Therefore, it is very important to timely identify patients with high development of acute renal failure, namely: patients with multiple injuries, burns, rhabdomyolysis and intravascular hemolysis, patients receiving potential nephrotoxins, patients undergoing surgical interventions during which there was a need for temporary interruption of renal blood flow. Special attention should be paid to maintaining the optimal values of the volume of intravascular fluid, cardiac output and normal urine flow in such patients. Caution when using potentially nephrotoxic drugs, early treatment in cases of cardiogenic shock, sepsis, and eclampsia can also reduce the incidence of acute renal failure.
Symptoms of acute form
Symptoms of an acute type of kidney failure develop very quickly: from several hours to a week. The patient has a sharp deterioration in the general condition. The duration of feeling unwell can be from 24 hours or more. Restore the functionality of the body is possible only with timely treatment.
In the clinical picture there are several stages:
Symptoms that appear in the first stage depend on the cause of the development of the pathology. For example, it may be signs of shock, intoxication. If the organ damage is infectious, then the patient has muscular weakness, fever and headache.
Intestinal infection causes indigestion and vomiting. Toxic damage is manifested by convulsions, anemia and jaundice. If OPN is caused by glomerulonephritis, then blood is detected in the urine, pain occurs in the lumbar region.
Symptoms of renal failure in men and women at the initial stage of the disease:
- pale skin
- lower blood pressure
- reduction of the daily volume of urine to 10%,
The course of oligoanuria depends on the correctness and timeliness of treatment.
The stage of oligoanuria is considered the most difficult and dangerous for the life of the patient. The following symptoms are observed:
- a sharp decrease in the daily volume of urine or a complete cessation of urine excretion,
- increased breathing
- increased blood pressure
- itching of the skin,
- loss of appetite,
- confusion, loss of consciousness,
- swelling of internal organs, subcutaneous tissue.
With a favorable outcome comes polyuria and recovery. First, diuresis gradually increases, and then all excess fluid is eliminated from the body, swelling disappears, and the blood is cleansed of toxins.
Polyuria is dangerous because there is a risk of dehydration and electrolyte imbalance. This stage lasts about a month, and then comes the process of recovery, which can last up to a year.
If competent treatment of acute renal failure was not carried out, then the terminal stage begins. It has the following symptoms:
- cough and sputum with blood clots,
- muscle cramps
- heart rhythm disorder
- loss of consciousness,
- internal bleeding
- subcutaneous hemorrhage.
Symptoms of the chronic form
Chronic type of renal failure has a less pronounced clinical picture. Initially, the disease may be asymptomatic or with mild signs. Characteristic manifestations are observed only at the last stage, when it is almost impossible to restore kidney function.
Symptoms of chronic kidney failure are listed below:
- dry mouth, thirst,
- pallor and dry skin as a result of anemia,
- the yellowness of the mucous membranes and skin,
- bruises and hemorrhages,
- itchy skin
- puffiness of face
- loss of muscle tone
- sleep disturbance
- memory impairment
- movement disorders in the legs and arms,
- increased urine output, especially at night. But then the daily volume of urine is reduced down to anuria,
- muscle paralysis
- respiratory failure,
- ammonia smell from the mouth,
- high blood pressure,
- loss of appetite and nausea.
The most common first symptom of CRF is the change in the volume of excretion and the color of the urine.
Urine becomes darker or lighter. The presence of blood clots in the urine is possible, because of what it becomes reddish.
The volume of urine initially increases and then begins to decrease. The patient feels heaviness and tightness in the bladder area. With uremia, ulcerative and erosive defects of the intestine and stomach are observed, which lead to bleeding. Often develop acute hepatitis.
If you do not take appropriate measures, death is possible. Therefore, you can not hesitate with treatment. It is important to undergo a full examination and follow all recommendations of the doctor.
Signs in children
Often there is acute and chronic renal failure in children. Symptomatology has some differences from those signs of renal failure, which are observed in adults.
Kidney failure in children causes the following symptoms:
- diarrhea with nausea and vomiting,
- growth retardation
- swelling of the arms and legs,
- enlarged liver
- inhibition, which is replaced by arousal,
- reduction of the daily amount of urine released,
- mood swings
- polyneuropathy, which is accompanied by weakness of the muscles, nervous tics and cramps.
Chronic and acute renal failure in children is also reflected in the appearance. It is observed:
- puffiness of face
- ammoniac breath odor,
- dullness and brittle hair,
- gray tint of skin,
- progressive dystrophy,
- prolonged vomiting
- dark-colored diarrhea with fetid odor,
If the child has the symptoms listed above, a line hospitalization is needed. With the progression of the disease, pulmonary edema occurs, immunity decreases, blood clotting is disturbed, encephalopathy develops. These processes are irreversible. Therefore, parents should be attentive to the health of their child.
Only timely hospitalization and effective therapy can prevent the development of bad consequences.
Consequences of kidney failure
Impaired kidney function leads to a number of negative consequences. OPN causes necrosis of the cortical substance of the kidneys. Dying off occurs as a result of prolonged circulatory disorders of the body. Blood stasis causes swelling. This condition increases the risk of developing an infection.
The worst effects are chronic renal failure. Toxic uremic substances accumulate in the body and adversely affect the nervous system. Observed convulsions and a violation of mental function, disorder of consciousness.
Poor kidney function leads to anemia. This condition results from a decrease in the level of the hormone erythropoietin, which is responsible for the formation of blood red cells. This increases the likelihood of blood infection.
Kidney failure causes problems in the cardiovascular system, hypertension. Increased pressure often leads to heart attacks and strokes.
CKD is also reflected in the state of bone tissue: osteodystrophy is observed. Suffering and gastrointestinal tract: reduced appetite and weight, there are internal bleeding. Diseases of metabolism are also characteristic of the disease.
ARF has the following consequences:
The most terrible and frequent consequence of kidney failure is mortality.
Depending on the severity of acute kidney failure and the presence of related complications, the mortality rate is 25-50% of the total number of patients.
The most common causes of death are:
- uremic coma, which results in damage to the nervous system,
- sepsis. When infected with blood, all organs, systems,
- serious circulatory disorders.
If the arrester is uncomplicated, then the functionality of the organ is restored in 90% of cases.
The ability to normalize the health of the kidneys depends on the stage of the disease, timeliness and correctness of therapy. In severe cases, the patient needs hemodialysis. Such patients are assigned a disability. But in general, the prognosis of acute renal failure with properly conducted activities is favorable.
- increased protein concentration in the blood,
- wrong diet, in which the food contains a lot of protein and phosphorus.
Previously, many patients died of renal failure.
Today, due to the use of hemodialysis and kidney transplantation, death has become less frequent.
To avoid the bad effects of kidney failure, you need to monitor your health and completely eliminate those factors that adversely affect the work of the urinary system. This is especially true of those people who are at risk. For example, kidney problems are often seen in diabetics.
Why does kidney failure arise and how does it manifest itself:
Thus, renal failure is of two types: chronic and acute. These forms have a different clinical picture. Chronic failure is less pronounced and therefore more dangerous. Obvious signs appear only at the last stages, when it is already impossible to restore the functionality of an organ.
The acute form proceeds with more severe symptoms and can also be fatal. The chances of a person returning to normal life depend on timely diagnosis and the right treatment regimen.
Renal arrester form
In the renal form of acute renal failure the kidney parenchyma is affected. It can be caused by inflammatory processes, toxic effects or pathologies of the renal vessels, which lead to insufficient blood supply to the organ. Renal ARF is a consequence of necrosis of the epithelial cells of the tubules of the kidneys. The result is a violation of the integrity of the tubules and the release of their contents into the surrounding tissues of the kidney. The following factors can lead to the development of renal acute renal failure:
- intoxication with various poisons, drugs, radiopaque compounds, heavy metals, snake bites or insects, etc.,
- kidney diseases: interstitial nephritis, acute pyelonephritis and glomerulonephritis,
- damage to the renal vessels (thrombosis, aneurysm, atherosclerosis, vasculitis, etc.),
- kidney injury.
Important: Long-term use of drugs that have a nephrotoxic effect, without prior consultation with the doctor can cause ARF.
A postrenal arrester develops as a result of an acute violation of the passage of urine. In this form of ARF, the kidney function is preserved, but the process of excretion of urine is difficult. Ischemia of the renal tissue may occur, since the pelvic overflowing with urine begins to compress the surrounding kidney tissue. The causes of postrenal ARF include:
- bladder sphincter spasm,
- obstruction of the ureters due to urolithiasis,
- tumors of the bladder, prostate gland, urinary canal, pelvic organs,
- injuries and hematomas,
- inflammatory diseases of the ureters or bladder.
Treatment and emergency care for acute renal failure
In acute renal failure, emergency care is to quickly transport a person to a hospital. In this case, the patient needs to ensure a state of rest, warmth and horizontal position of the body. It is best to call an ambulance, as in this case, qualified doctors will be able to take all the necessary measures directly to the site.
In acute renal failure treatment is carried out taking into account the stage of the disease and the cause of it caused. After eliminating the etiological factor, it is necessary to restore homeostasis and renal excretory function. Given the cause of the surge arrester, you may need:
- antibiotics for infectious diseases
- replenishment of fluid volume (with a decrease in circulating blood volume),
- the use of diuretics and fluid restriction to reduce swelling and increase urine production,
- taking heart drugs in violation of the work of the heart,
- taking drugs to lower blood pressure if it rises,
- surgery to restore damaged kidney tissue injury or to remove obstacles that prevent the flow of urine,
- taking drugs to improve blood supply and blood flow in the nephrons,
- detoxification of the body in case of poisoning (gastric lavage, the introduction of antidotes, etc.).
For removal of toxic products from the blood, hemodialysis, plasmapheresis, peritoneal dialysis, hemosorption are used. Acid-base and water-electrolyte balance is restored by administering saline solutions of potassium, sodium, calcium, etc. These procedures are used temporarily until renal function is restored. With timely treatment, ARF has a favorable prognosis.
We talk about the symptoms and treatment of chronic renal failure in this article.