Renal failure
The functional unit of the kidney is the nephron, which is composed of many capillary glomeruli. This is where urine filtration processes take place. And the processes of reabsorption for the purpose of subsequent excretion occur in the tubules. Each human kidney contains about one million nephrons. When 90% of the nephrons fail, renal failure begins, in which the kidneys cannot cope with the usual load.
Renal failure: causes
In the bloodstream of the body, the kidneys are peripheral organs. In any stressful situation, the blood circulation is centralized. First of all, vital organs are supplied with oxygen and nutrients: heart - brain - lungs. Despite the importance of kidney function, they are "overboard" and receive minimal amounts of blood. Therefore, the kidneys are considered "shock organs".
Almost any prolonged stressful situation in one way or another affects the work of the urinary system. Renal failure has the following causes:
- Shock of any nature;
- Collapse - a sharp drop in blood pressure;
- Traumatic kidney injury;
- Acute lesions of the renal parenchyma in inflammatory and autoimmune diseases (pyelonephritis, glomerulonephritis);
- Injury or removal of a single kidney;
- Acute poisoning of an organism of any nature: from natural poisons to medicinal substances;
- Diseases leading to a violation of the outflow of urine;
- Late gestosis;
- Neoplastic kidney disease.
When the blood circulation is centralized, the renal nephrons are "turned off" from the general circulation, and the blood passes through the opened reserve capillaries, bypassing the filtration stage. With kidney disease, the capillaries of the renal glomeruli are destroyed, as a result of which acute renal failure develops, the symptoms of which are the main function of the organs - excretory.
Renal failure: symptoms
When a particular organ is affected, all the symptoms indicate not a failure or lack of its functions. Because the kidneys remove liver-neutralized substances from the blood when acute renal failure develops, all metabolites continue to circulate in the blood throughout the body, including the brain. It is affected by specific toxins, primarily ketone bodies. The patient has disorders of consciousness: from stupor to coma. Mood changes: either euphoria occurs, or depression. There is no appetite, but vomiting appears, which does not bring any relief. As a compensatory reaction, diarrhea appears - excess fluid is excreted through the gastrointestinal tract. Systemic edema appears, which differ from cardiac edema by a rapid increase - literally in a few hours.
Acute renal failure, first of all, is manifested by the main, cardinal symptoms:
- Oliguria;
- Anuria.
With oliguria, urine output is less than 400 ml per day. With anuria, 50 ml is released in 24 hours.
Stages of renal failure
In acute failure of kidney function, three successive stages are distinguished:
- Initial;
- Oliguric;
- Recovery.
In the initial stage, the manifestations of the disease are causal. If it is shock or poisoning, symptoms of shock or intoxication are noted first. General symptoms of weakness do not directly indicate that renal failure is developing, which is most often not treated during this period.
With oliguria, there is a pronounced picture of the disease, therefore, emergency measures are taken. Drugs are used to improve blood flow to the kidneys. The volume of circulating blood is replenished. The fight against edema is carried out: infusion of saline and protein solutions. Diuretics are not used in the second phase. Stimulation of urination has no pathogenetic rationale, since diuretics do not improve the blood supply to the nephrons.
The recovery stage is characterized by polyuria. An increased amount of urine indicates that the filtration function of the kidneys is working. Renal failure stops, therefore, the digestive, respiratory and motor systems return to normal. If a person was in a coma, consciousness returns to him. During this period, therapeutic measures are taken to replenish fluid loss.
Renal recovery depends on the impact of the damaging factor. Treatment of the final stage of renal failure is carried out in an outpatient clinic, under the control of urine tests.
Renal failure: symptoms in children
In children, the disease progresses more rapidly than in adults. This is due to the anatomical and physiological characteristics and the reasons why renal failure develops in children of different ages:
- Neonatal period - renal vascular thrombosis or disseminated intravascular coagulation syndrome;
- From infancy to three years - hemolytic uremic syndrome - a disease associated with the blood system;
- Preschool and school age - glomerulonephritis or acute pyelonephritis.
Treatment depends on the cause of the disease, but all procedures are performed in the same way as for adults. Only the dosages of medications change.
Chronic renal failure: symptoms
In a chronic course, renal failure is manifested not only by dysuric disorders, but violations of all kidney functions are noted:
- Blood pressure rises;
- Blood hemoglobin decreases;
- Calcium is lost, osteoporosis develops;
- The contractile function of the myocardium changes.
As a rule, chronic renal failure, treatment is forced to take place constantly, in the hemodialysis unit.
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The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
