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Symptoms of acute renal failure
Last reviewed: 23.04.2024
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In the course of acute renal failure, there are 4 stages:
- initial - the effect of the damaging agent on the epithelial cells of the tubules (duration is several hours);
- oligo-anuric - maintaining a relatively low GFR, a decrease in diuresis increases azotemia (this stage can last several days, in case of dialysis, the development of the next stage is possible);
- polyuric - restoration of water-discharge function of the kidneys (several weeks continue, about 80% of patients in this period suffer an infection, which can be the cause of death);
- recovery - the stage of slow recovery of normal glomerular filtration rate and tubular functions (duration is 6-24 months).
In the initial stage of acute renal failure, the clinical picture is dominated by the symptoms of the pathological process, which is complicated by kidney damage, so oliguria, metabolic acidosis, hyperkalemia and azotemia are usually obscured by manifestations of the underlying disease. Oliguria less than 0.3 ml / (kghch) - the main clinical manifestation of acute renal failure. In the oligoanuric stage, a decrease in diuresis and an increase in azotemia prevail, the phenomena of uremic intoxication. During this period, mortality is highest. With adequate treatment following the oligoanuric stage, polyuric acute renal failure occurs, in which diuresis is 2-3 times higher than the age norm and is combined with low urine osmolarity. Hyponatremia is replaced by hypernatremia, and hyperkalemia is hypokalemia. At this stage in the state of the child there is no noticeable improvement, inhibition, muscle hypotension, hyporeflexia, paresis and paralysis persist. In the blood, high rates of azotemia, and in the urine a lot of protein, leukocytes, erythrocytes, cylinders, which is associated with the release of dead cells tubular epithelium and resorption of infiltrates. At this stage, often a layering of the infection occurs until the development of the septic state. The duration of the recovery phase is from several months to several years until the complete restoration of the nephron function.
In uncomplicated cases, metabolic acidosis is detected in the blood on the background of acidotic respiration and respiratory alkalosis. In complicated cases, acidosis is replaced by metabolic alkalosis (prolonged vomiting) or combined with respiratory acidosis (pulmonary edema). Changes in electrolyte metabolism are characterized by hyponatremia, hypochloraemia, hypermagnesia, hyperphosphatemia, hypocalcemia, which are combined with clinical symptoms reflecting the effect of these disorders on the central nervous system and blood circulation (somnolence or coma, convulsions, heart rhythm disturbances). In most children, hyperkalemia is also noted, but in some newborns, despite a sharp decrease in diuresis, hypokalemia occurs (due to vomiting and profuse diarrhea).
Ureemic intoxication is manifested in the appearance of skin itch, anxiety or inhibition, indomitable vomiting, diarrhea, signs of cardiovascular insufficiency.
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