Acute renal failure - Treatment

Treatment of acute renal failure is determined by the etiology, form and stage of acute renal failure. As is known, both prerenal and postrenal forms are necessarily transformed into the renal form during development. That is why treatment of acute renal failure will be successful with early diagnosis of the disease, determination of its cause, and timely initiation of efferent therapy.

Treatment of acute renal failure has the following goals:

• treatment of the underlying disease that led to the development of acute renal failure;
• restoration of water-electrolyte balance, as well as correction of acid-base balance;
• renal function replacement;
• ensuring adequate nutrition;
• treatment of concomitant diseases.

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Indications for hospitalization

All patients with suspected or confirmed acute renal failure are subject to emergency hospitalization in a multidisciplinary hospital with a hemodialysis department.

By the time of discharge, patients still have polyuria with normalized concentrations of nitrogen metabolites and electrolytes. During the recovery period, patients who have suffered acute renal failure require long-term outpatient observation and treatment by a nephrologist at their place of residence for at least 3 months.

Non-drug treatment of acute renal failure

Treatment of acute renal failure must begin with therapy for the underlying disease that caused it.

To assess the degree of fluid retention in the patient's body, daily weighing is desirable. For a more accurate determination of the degree of hydration, the volume of infusion therapy and indications for it, it is necessary to install a catheter in the central vein. It is also necessary to take into account the daily diuresis, as well as the patient's arterial pressure.

In prerenal acute renal failure, it is necessary to quickly restore the circulating blood volume and normalize blood pressure.

For the treatment of acute renal failure caused by various medicinal and non-medicinal substances, as well as some diseases, it is necessary to start detoxification therapy as early as possible. It is advisable to take into account the molecular weight of the toxins that caused acute renal failure and the clearance capabilities of the applied method of efferent therapy (plasmapheresis, hemosorption, hemodiafiltration or hemodialysis), the possibility of the earliest possible administration of the antidote.

In postrenal acute renal failure, immediate drainage of the urinary tract is necessary to restore adequate urine flow. When choosing the tactics of surgical intervention on the kidney in conditions of acute renal failure, information on the sufficient function of the contralateral kidney is necessary before the operation. Patients with a single kidney are not so rare. During the polyuria stage, which usually develops after drainage, it is necessary to monitor the fluid balance in the patient's body and the electrolyte composition of the blood. The polyuric stage of acute renal failure can manifest itself as hypokalemia.

Drug treatment of acute renal failure

With unimpaired passage through the gastrointestinal tract, adequate enteral nutrition is necessary. If this is impossible, the need for proteins, fats, carbohydrates, vitamins and minerals is satisfied with intravenous nutrition. Taking into account the severity of the glomerular filtration disorder, protein intake is limited to 20-25 g per day. The required caloric intake should be at least 1500 kcal/day. The amount of fluid required by the patient before the development of the polyuric stage is determined based on the volume of diuresis over the previous day and an additional 500 ml.

The greatest difficulties in treatment are caused by a combination of acute renal failure and urosepsis in a patient. The combination of two types of intoxication at once - uremic and purulent - significantly complicates treatment, and also significantly worsens the prognosis for life and recovery. When treating these patients, it is necessary to use efferent methods of detoxification (hemodiafiltration, plasmapheresis, indirect electrochemical oxidation of blood), the selection of antibacterial drugs based on the results of bacteriological analysis of blood and urine, as well as their dosing taking into account the actual glomerular filtration.

Treatment of a patient with hemodialysis (or modified hemodialysis) cannot serve as a contraindication to surgical treatment of diseases or complications that have led to acute renal failure. Modern possibilities of monitoring the blood coagulation system and its drug correction allow avoiding the risk of bleeding during operations and in the postoperative period. For efferent therapy, it is advisable to use short-acting anticoagulants, such as sodium heparin, the excess of which can be neutralized by the end of treatment with an antidote - protamine sulfate; sodium citrate can also be used as a coagulant. To monitor the blood coagulation system, a study of activated partial thromboplastin time and determination of the amount of fibrinogen in the blood are usually used. The method for determining the blood coagulation time is not always accurate.

Treatment of acute renal failure even before the development of the polyuric stage requires the administration of loop diuretics, for example furosemide up to 200-300 mg per day in divided doses.

To compensate for catabolic processes, anabolic steroids are prescribed.

In hyperkalemia, intravenous administration of 400 ml of 5% glucose solution with 8 U of insulin, as well as 10-30 ml of 10% calcium gluconate solution is indicated. If hyperkalemia cannot be corrected by conservative methods, the patient is indicated for emergency hemodialysis.

Surgical treatment of acute renal failure

To replace kidney function during oliguria, any method of blood purification can be used:

• hemodialysis;
• peritoneal dialysis;
• hemofiltration;
• hemodiafiltration;
• low-flow hemodiafiltration.

In case of multiple organ failure, it is better to start with low-flow hemodiafiltration.

Treatment of acute renal failure: hemodialysis

Indications for hemodialysis or its modification in chronic and acute renal failure are different. In the treatment of acute renal failure, the frequency, duration of the procedure, dialysis load, filtration rate and dialysate composition are selected individually at the time of examination, before each treatment session. Hemodialysis treatment is continued, preventing an increase in the urea content in the blood above 30 mmol/l. When acute renal failure resolves, the concentration of creatinine in the blood begins to decrease earlier than the concentration of urea in the blood, which is regarded as a positive prognostic sign.

Emergency indications for hemodialysis (and its modifications):

• "uncontrolled" hyperkalemia;
• severe hyperhydration;
• hyperhydration of lung tissue;
• severe uremic intoxication.

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Planned indications for hemodialysis:

• blood urea content greater than 30 mmol/l and/or creatinine concentration greater than 0.5 mmol/l;
• pronounced clinical signs of uremic intoxication (such as uremic encephalopathy, uremic gastritis, enterocolitis, gastroenterocolitis);
• overhydration;
• severe acidosis;
• hyponatremia;
• rapid (within a few days) increase in the content of uremic toxins in the blood (daily increase in urea content exceeding 7 mmol/l, and creatinine - 0.2-0.3 mmol/l) and/or decrease in diuresis

With the onset of the polyuria stage, the need for hemodialysis treatment disappears.

Possible contraindications to efferent therapy:

• afibrinogenemic bleeding;
• unreliable surgical hemostasis;
• parenchymal bleeding.

A two-way catheter inserted into one of the central veins (subclavian, jugular or femoral) is used as vascular access for dialysis treatment.

Approximate periods of incapacity for work

Depending on the underlying disease that led to the development of acute renal failure, the period of disability can range from 1 to 4 months.

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Further management

Patients should be advised to limit physical activity and follow a diet with moderate protein content.

Prognosis of acute renal failure

A large number of surviving patients experience complete recovery of renal function; in 10-15% of cases, recovery is incomplete: renal function is reduced to varying degrees.