As distinct from prerenal causes, renal causes of renal failure include all pathological conditions which affect parenchyma of kidneys. The most often reasons of acute kidneys affection are acute glomerulonephrites, interstitial nephritises, renotrophic intoxications, clottage of renal vessels, kidney infarct, etc. It is necessary to note, that the pathological process can affect both renal glomuluses (glomerulonephritis), disturbing the process of filtration, and epithelium of tubules (nephritis, intoxications), what results in their congestion and their disturbed reabsorbtion.
One of common forms of renal failure is congestion of renal tubules by haemoglobin of decayed erythrocytes that usually occures during massive hemolysis. Renal failure develops also in case of nephrectomy of both kidneys or their serious traumas.
The most common postrenal causes of renal failure are acute obstruction of ureters of both kidneys which can occure in case of urolithiasis, prelum of ureters by a ligature (during surgical operations), hematoma (because of traumas), tumour, etc. As a rule, simultaneous functional disorder of both ureters happens quite seldom.
Treatment of acute renal failure at the early stage of development is directed on liquidation of the shock. Also diuretics and anticoagulants are often prescribed. Balanced and healthy nutrition plays an important role as well: a low-protein diet with daily energy value no more than 1500-2000 kcal is advised. Among other medicinal preparations used to treat acute renal failure are anabolics and polyvitaminic preparations. In case of infectious complications antibiotics are prescribed.
To normalize diuresis it is necessary to maintain an optimum balance of a liquid in the organism of a patient suffering from renal failure. Liquid is taken either orally, or intravenously. It is important not to overdose the amount of liquid because it can increase hydremia and can become the reason of water poisoning.
Disintoxication therapy (haemodialysis, hemofiltration, peritoneal dialysis, hemosorption) is necessary, if acute renal failure (ARF) is caused by intoxication of the organism. Then, ARF treatment is focused on restoration of water and electrolytic balance (for normal diuresis). In case of dehydration sodium chloridum, plasma, albuminum, glucose are used, together with increased consumption of water. Electrolits (potassium, sodium chloridum) are very helpful in normalizing electrolytic balance. Food rich in potassium is necessary to prevent hypokalemia.
Treatment of chronic renal failure (CRF) includes conservative therapy (diet, disintoxication), dialysis and kidney transplantation. The diet should be based on food with low amount of proteins and rich in fats, carbohydratesm and vitamins. Daily consumption of water should be not less than 1500-2000 ml. It is recommended to inject solution of sodium carbonate, glucose, and sodium chloridum.
At the late stages of CRF such methods of a dialysis are applied: constant peritoneal dialysis, haemodialysis. The terminal stage of chronic renal failure that has developed on the background of chronic pyelonephritis, chronic glomerulonephritis, polycystosis of kidneys, and hydronephrosis, is the indication for transplantation of a kidney.
There are prerenal, renal and postrenal causes of renal failure.
Disturbance of blood supply of kidneys is the main prerenal cause of renal failure (RF). It is assumed that the process of renal filtration (the first stage of uropoiesis) depends entirely on the amount of blood flowing to kidneys. This amount is determined by arterial pressure. Therefore, in most cases, acute renal failure (ARF) is caused by a sharp drop of arterial pressure, because it reduces significantly the amount of blood going to kidneys.
The cause of such a drop is a critical condition, a shock, which is characterized by a severe disorder of blood circulation. This shock condition is cause by a considerable loss of blood, traumas, burns (a hypovolemic shock), heart-work disorder (a cardiogenic shock in case of myocardial infarction), a septic shock (in case of sepsis), an anaphylactic shock (when getting specific allergens in the sensitized organism) and so forth.
Thus, during a critical drop of blood supply of kidneys the process of urine filtration becomes impossible and uropoiesis stops. This state is called anuria.
Renal failure is a pathological condition which is characterized by a complete or partial renal disfunction in maintaining chemical constancy of the organism. Renal failure is accompanied with improper process of secretion and removal of urine, water-salt, acid-alkaline and osmotic imbalance, slow removal of nonvolatile acids and nitrous products (urea, creatinine, urinary acid, etc.).
From the point of view of pathogeny and clinical development of the disease there are two types of renal failure: acute and chronic.
Acute renal failure (ARF) is a severe disfunction of one or both kidneys that affects either all nephrons, or all parts of canaliculi, or glomerular system. ARF develops as a result of affection of various pathological exogenous or endogenous causes on renal parenchyma.
Diagnostics is based first of all on the anamnesis: whether the patient used toxicant products or medicinal preparations, attempted to do an abortion, etc. Further, it is necessary to exclude obstruction of urinary ways with the help of catheterization. Among other methods that are used to diagnose acute renal failure are: ultrasonic examination, computer tomography, radioisotopic renography, cystoscopy.
Chronic renal failure (CRF) is a pathological symptom complex that is caused by rapid decrease of nephrons and their functioning, as well as glomerular filtration. CRF develops as a consequence of such diseases and factors as: chronic glomerulonephritis and pyelonephritis, metabolic disease and disturbances (diabetes, gout), anomalies of kidneys and ureters (hypoplasia of kidneys, polycystosis of kidneys, neuromuscular dysplasia of ureters), intoxication with lead, mercury, analgesics, antibiotics, etc.
When this symptoms of this pathological condition occure, it is necessary to consult your doctor immediately. It is of vital importance to start the appropriate course of treatment without a delay.