Anuria is a pathological condition in which the amount of urine excreted is less than 50 ml per day. It is detected in acute renal failure of various origins, in the final stage of chronic renal failure, in severe cardiovascular and multiple organ failure, various shock conditions, renal vascular thrombosis, and urolithiasis. The cause of anuria is established on the basis of anamnesis, physical examination data, hardware and laboratory techniques. Treatment includes infusion therapy, extracorporeal detoxification, drugs, surgical methods.
Anuria is a serious pathological condition that requires emergency therapeutic measures; if not corrected, it becomes the cause of death. Depending on the etiology, the following variants of anuria are distinguished:
- Arenal. Rare form. It is observed in the absence of kidneys in newborns, after bilateral nephrectomy or removal of the only functioning kidney in people of other ages.
- Prerenal. It is caused by a violation or cessation of blood circulation in the kidneys due to a critical decrease in blood pressure or blockage of the lumen of blood vessels.
- Renal. It occurs as a result of damage to the kidney parenchyma in severe nephrological diseases, the intake of nephrogenic poisons, and some other conditions.
- Postrenal. Urine is formed, but cannot enter the bladder due to blockage of the ureter by a stone, tumor, or inflammatory infiltrate.
- Reflex. It is caused by a failure of the nervous regulation of the process of urination against the background of various adverse influences, for example, hypothermia or rough instrumental manipulations.
Why does anuria occur?
Organ failure
There is prerenal anuria. The condition develops in acute right ventricular failure, usually due to pulmonary embolism. Against the background of stagnation in the systemic circulation, edema, shortness of breath, pain in the region of the heart and right hypochondrium occur. Anuria also accompanies the final stage of chronic cardiovascular insufficiency, which has developed as a result of heart defects, arterial hypertension, emphysema, pneumosclerosis, cardiomyopathies, myocarditis and other pathologies.
Multiple organ failure is formed in patients with peritonitis, sepsis, infectious-toxic shock, severe polytrauma. Manifested by shortness of breath, cyanosis, edema, hemodynamic disorders, liver dysfunction, abdominal pain. Psychomotor agitation is replaced by depression of consciousness, tachycardia - bradycardia. The amount of urine decreases, anuria develops in severe cases in the decompensation phase.
shock states
One of the hallmarks of any shock is a drop in blood pressure. With a decrease in systolic blood pressure to 40-50 mm and below, the blood supply to the kidneys is sharply disturbed, which entails the formation of first prerenal oliguria, and then anuria. The symptom is observed in severe course, is detected in the following conditions:
- Septic shock. It is provoked by extensive purulent processes (abscesses, phlegmon), festering wounds and open fractures. It can occur against the background of taking immunosuppressants and a long stay in the intensive care unit. It is accompanied by febrile temperature, convulsions, respiratory failure, enlargement of the liver and spleen.
- Cardiogenic shock. Diagnosed with extensive heart attacks, severe myocarditis, cardiac tamponade, massive pulmonary embolism, poisoning with cardiotoxic poisons. At first, cardiac pains predominate, then respiratory failure, pulmonary edema, tachycardia, and severe hypotension join. Reduced diuresis or lack of urine is complemented by impaired consciousness, the development of stupor or coma.
- Traumatic shock. More often formed with severe injuries. May be the result of extensive operations. At first, the victim is excited, frightened, anxious, complains of pain. Then he becomes drowsy and lethargic. With further deterioration of the condition, convulsions, impaired consciousness are noted. Symptoms of intoxication include nausea, vomiting, dark urine, oliguria, and anuria.
- hypovolemic shock. It is found with external and internal traumatic and non-traumatic bleeding, extensive burns, accumulation of plasma in the abdominal cavity with pancreatitis and peritonitis, fluid loss with severe intestinal infections. There are tachycardia, hypotension, pallor, impaired consciousness, a decrease in the amount of urine up to anuria.
- Burn shock. Anuria or severe oliguria is characteristic of an extremely severe shock condition that occurs with deep burns of more than 40% of the body area. Develop at an early stage. Urine black or dark brown. Disorders of thermoregulation, confusion, nausea, repeated vomiting, intestinal paresis are noted.
Anuria - lack of urine
Vascular damage
Another provoking factor of prerenal anuria is the blockade of blood flow in the vessels of the kidneys. The symptom is more often observed with bilateral thrombosis of the renal veins, sometimes with a reflex cessation of the activity of the second kidney against the background of unilateral occlusion. Typical sharp pains in the lower back, blood in the urine, decreased urination up to anuria, weakness, nausea, vomiting. Another possible reason for the cessation of blood circulation is the compression of blood vessels by tumors, scars and inflammatory infiltrates.
Chronic renal failure
Renal anuria is found at the final stage of CRF. Causes of impaired renal function are:
- chronic glomerulonephritis;
- chronic pyelonephritis;
- hereditary nephritis;
- polycystic;
- amyloidosis;
- diabetic glomerulosclerosis;
- nephroangiosclerosis;
- bilateral tuberculosis of the kidneys.
Signs of the end stage of chronic renal failure are thirst, the smell of ammonia from the mouth, weight loss, skin itching, grayish-yellow skin tone, decreased muscle tone, muscle twitching. Anuria is combined with increasing anemia, hemorrhagic syndrome, ascites, pulmonary edema.
Acute renal failure
In transfusion shock, transfused red blood cells are destroyed, forming unbound hemoglobin, which damages kidney tissue. There is anxiety, agitation, cyanosis, pallor or marbling of the skin with reddening of the face, tachycardia, shortness of breath, back pain. Subsequently, an imaginary improvement is possible, which is replaced by swelling and yellowness of the skin. Hematuria, oliguria or anuria indicate the development of acute renal failure.
The syndrome of prolonged crushing is formed in victims of earthquakes, building collapses, industrial accidents. A type of pathology is the positional compression syndrome that occurs when sleeping in a non-physiological position after taking alcohol or drugs. After the pressure is removed, the condition briefly improves, and then worsens again. Oliguria is observed, urine is the color of meat slops, in severe cases anuria develops. Possible endotoxic shock, multiple organ failure.
Toxic nephropathy is formed when nephrotoxic (heavy metal salts, phenol, gasoline, ethylene glycol, fungal toxins) or hemolytic (copper sulfate, acetic acid, snake venom) substances enter the body. Anuria is detected in severe pathology, may be accompanied by uremic coma.
Blockade of the ureter
Postrenal anuria is potentiated by bilateral calculi in the ureters with KSD, less often by reflex cessation of the work of the second kidney with blockade of one ureter. Patients complain of extremely intense pain in the lumbar region, sometimes with irradiation to the groin. Patients are restless, rushing about. With bilateral damage and the lack of timely assistance, the development of acute renal failure is possible. In addition, the ureter can be compressed from the outside by scars, tumors, or inflammatory foci.
Reflex anuria
The occurrence of reflex anuria may be due to hypothermia. With a moderate lesion, disturbances in the nervous regulation are aggravated by a decrease in renal blood flow. With severe hypothermia, neurogenic and vascular disorders are complemented by the development of acute renal failure. Sometimes rough therapeutic and diagnostic manipulations in the urinary tract, for example, cystoscopy or bougienage of the urethra, lead to the refrector type of anuria.
Diagnostics
Determining the cause of a symptom is the responsibility of a nephrologist or urologist. Anuria accompanies serious conditions, which are often associated with complex violations of body functions and pose a danger to life, therefore, intensive care physicians are involved in the examination and treatment. Establish the time of onset of the symptom, previous disorders, predisposing factors. Conduct an external inspection. The examination program includes the following procedures:
- Sonography. Ultrasound of the kidneys and ureters makes it possible to confirm changes in the renal parenchyma, to identify stones. In the course of ultrasound examination of the renal vessels, hemodynamic disturbances are determined. Patients with KSD undergo an ultrasound of the bladder to detect stones in the lower urinary tract.
- Beam methods. In the process of survey urography, X-ray-positive stones are viewed. In case of toxic nephropathy and ICD, CT of the kidneys is informative, allowing to visualize even minor changes in the renal tissue, to clarify the location, type and size of stones. CT phlebography is recommended if necessary to establish the position of the thrombus, it is prescribed with caution due to the toxicity of contrast agents.
- Heart research. Patients with cardiogenic shock, cardiovascular and multiple organ failure require electrocardiography. According to echocardiography, the pumping function of the myocardium is assessed. During the MRI of the heart, malformations, coronary artery disease and other cardiac pathologies are diagnosed.
- Laboratory tests. Due to the impossibility or difficulty in obtaining urine, the leading role is played by biochemical parameters of blood, indicating the severity of impaired renal function (creatinine, urea, electrolytes). In case of organ failure, an extended laboratory examination is carried out with the determination of CBS, glucose, hemoglobin, liver tests, etc.
- Other research. The list of instrumental techniques depends on the type of pathology. In case of traumatic shock, x-rays of fractures are performed, and if internal bleeding is suspected, endoscopic techniques are used: laparoscopy, gastroscopy, colonoscopy. Due to the serious condition of the patient, the possibilities of examination may be limited.
Hemodialysis
Treatment
Conservative therapy
Therapeutic tactics is determined by the nature of the pathology that provoked anuria:
- Organ failure. In heart failure, cardiac glycosides, nitrates, vasodilators, diuretics, anticoagulants, beta-blockers are used. Patients with multiple organ failure require plasma transfusions, infusion therapy, antibiotics, steroid hormones.
- shock states. Therapeutic measures include the impact on the cause of the development of shock and the normalization of vital signs. Carry out blood transfusions, transfusion of colloid and crystalloid solutions. Oxygenation is used, according to indications, mechanical ventilation is performed. The impact on etiofactors includes pain relief of fractures, the appointment of narcotic analgesics, nitrates, cardiotonic drugs, steroids, antiarrhythmic drugs.
- Renal failure. A special diet is required. At certain stages, stimulation of diuresis with the help of diuretics is indicated. Methods of extracorporeal detoxification are widely used: plasmapheresis, hemosorption, hemofiltration, peritoneal dialysis, in the late stage of CRF - periodic hemodialysis. Similar measures are recommended for toxic nephropathy.
- Urolithiasis disease. In the presence of a tendency to independent discharge of stones, terpenes are prescribed. To eliminate renal colic, antispasmodics, analgesics and thermal procedures are used. In most cases, conservative methods are ineffective, surgery is required.
Surgery
In pathological conditions accompanied by anuria, the following interventions are performed:
- CKD: kidney transplant.
- ICD: ureterolithoextraction, ureterolithotomy, remote and contact ureterolithotripsy.
- Cardiogenic shock: balloon angioplasty, artificial ventricle, intra-aortic balloon counterpulsation.
- Hypovolemic shock: surgical elimination of the source of bleeding (ligation of blood vessels, stitching of gastric ulcers, suturing of liver ruptures, splenectomy, etc.).
- Renal vein thrombosis: thrombectomy, installation of a cava filter.