Acute kidney failure

Acute renal failure is a syndrome caused by a sudden (within a few hours or days) potentially reversible impaired renal or kidney function, which developed based on the lesion of the canal apparatus (necrosis of the tubules) due to the effects of exogenous or endogenous factors.

[1], [2], [3], [4], [5 -]

Epidemiology

On average, in various countries, 1 million population accounts for 30 to 60 cases of acute renal failure per year. The share of nephrological patients with acute renal failure in intensive care units is 10-15%. Despite the constant improvement of hemodialysis technology and the creation of new dialysis and filtration technologies, the mortality rate during the development of acute renal failure is from 26 to 50%, and with a combination of acute renal failure and sepsis, it reaches 74%. Acute renal failure in pediatric practice occurs with a frequency of 0.5-1.6%, and in newborns it reaches 8-24%. At the same time, a share of rennal and triumphant acute renal failure accounts for 15%.

[7], [8], [9], [10], [11 -]. [13], [14], [15], [16]

Causes of the acute renal failure

How acute renal failure is developing is still not known, however, four main reasons for its development are noted:

• Tubular obstruction;
• Interstitial edema and passive reverse current of the glomerular filtrate at the level of the tubules;
• Kidney hemodynamics disorder;
• Disseminized intravascular coagulation.

On a large statistical material, it is currently proved: the morphological basis of acute renal failure is the lesion of the mainly channel apparatus in the form of nephrothelial necrosis with damage to the basal membrane or without it; With an uncontrolled defeat of glomeruli. Some foreign authors use the Russian-speaking term “acute tubular necrosis” as a synonym for the “acute renal failure”. Morphological changes, as a rule, are reversible, therefore, the clinical and biochemical symptom complex is also turned. Nevertheless, in a few cases, in severe endotoxic (less often exotoxic) effects, it is possible to develop bilateral total or subtotal cortical necrosis, which differ in morphological and functional irreversibility.

[17], [18], [19], [20]

Pathogenesis

For a long time, renal failure was identified with uremia, however, pathological changes in the body in case of impaired renal function are much more complicated, more dynamic and cannot be explained only by the accumulation of nitrogenous toxins. Depending on the speed and severity of a decrease in glomerular filtration, acute renal failure and chronic renal failure are distinguished.

[21], [22], [23], [24], [25]

Symptoms of the acute renal failure

A thorough history of the anamnesis is necessary with the clarification of information about the recently transferred acute diseases, the presence of chronic diseases, taking drugs, contact with toxic substances and clinical symptoms of intoxication.

Acute renal failure proceeds with the following symptoms: dry mouth, thirst, shortness of breath (extracellular hyperhydration develops, the first sign of which is the interstitial edema of the lungs), edema of the soft tissues in the lumbar region, the edema of the lower extremities (it is also possible to accumulate fluid in the cavities: hydrotorax, hydrotorax, hydrotorax, hydroerac ascites, the development of cerebral edema and seizures is not excluded).

[26], [27]

Forms

The following forms are distinguished: interruption (hemodynamic), rennal (parenchymal) and praenal (obstructive) acute renal failure. Most often, rennated acute renal failure (up to 70% of cases) is found. The most common reason for the interrupted acute renal failure is the development of hypotension against the background of problems with the cardiovascular system and the patient's body dehydration. The critical level of arterial pressure is considered 60 mm Hg, and below it, the urination ceases. Renal acute renal failure develops with damage to the kidney parenchyma (according to different authors, up to 25% of cases), most often caused by the action of nephrotoxic substances (for example, drugs). Wrestling acute renal failure is associated with impaired obstruction of the urinary tract.

[28], [29], [30]

Diagnostics of the acute renal failure

Currently, there are no specific tests that allow at the very early stage to diagnose “acute renal failure”. The most reliable and simple marker of acute renal failure is a continuous increase in creatinine levels. Patients in serious condition need daily control of diuresis and electrolyte composition of blood.

Acute renal failure has typical diagnostic criteria: at clinical blood test moderate anemia and an increase in ESR can be observed. Anemia in the first days of anuria is usually relative. Delivered by hemodilization, does not reach a high degree and does not require correction. Blood changes are characteristic of exacerbation of the urinary tract infection. With acute renal failure, a decrease in immunity is observed, as a result of which there is a tendency to develop infectious complications: pneumonia, suppuration of operational wounds and places of reaching the skin of catheter installed in the central veins, etc.

At the beginning of the Oliguria period, the urine is dark, contains a lot of protein and cylinders, its relative density is reduced. During the period of diurez restoration, the low relative density of urine is preserved, proteinuria, almost constant leukocyturia as a result of the release of dead tubular cells and resorption of interstitial infiltrates, cylinder, erythrocyturia.

[31], [32], [33], [34], [35]. [36]

Treatment of the acute renal failure

Acute renal failure is treated depending on the etiology, form and stage of this disease. As you know, both the interruption and triumphant forms in the development process are necessarily transformed into a renal form.

That is why the treatment of acute renal failure will be successful in the early diagnosis of the disease, determining its cause, as well as the timely beginning of efferent therapy.

Prevention

Acute renal failure can be prevented by adequate treatment of the underlying disease, in which acute renal failure is possible. In case of interrupt acute renal failure, it is necessary to strive for timely correction of hypovolemia. If possible, it is necessary to avoid nephrotoxic drugs, and if they are used according to indications, to take into account SKF.

In patients from risk groups, a sharp decrease in blood pressure and BCC should be avoided, the use of X-ray contact drugs, nephrotoxic medicines, as well as drugs that actively affect the renin-aldosterone-angiotensin system and reduce renal blood flow.

Apply drugs, especially antibiotics, NSAIDs, sodium heparin and saluretics, follows strict indications, with caution. At the same time, with infections caused by nephrotropic pathogens, the prescription of antibiotics is an important component of the prevention of acute renal failure.

As cytoprotectors that reduce the risk of acute renal failure, slow calcium channels (verapamil), glycine, theophylline, antioxidants, vitamin E, etc.) are recommended. Postoperative acute renal failure is prevented by using mannitol and loop diuretics.

[37], [38], [39], [40], [41]