Acute Renal Failure - Causes, Symptoms and Treatment .MF .
Renal failure - a violation of secretory (excretory) renal function with the accumulation of toxins in the blood of nitrogen, normally removed from the body in urine.It may be acute or chronic.The following is considered acute renal failure, and chronic, see the article: Chronic renal failure.
Acute renal failure
Acute renal failure (ARF) - a syndrome of sudden, rapid reduction or termination of the functions of both kidneys (or a single kidney), leading to a sharp increase in products of nitrogen metabolism in the body, breach of the general metabolism.Impaired function of the nephron (the structural unit of the kidney) occurs due to a reduction in renal blood flow and a sharp decline in the delivery of oxygen to them.
Acute renal failure develops in a few hours to 1-7 days and continues over 24 hours.With timely treatment and correctly spent treatment ends with complete recovery of renal function.Acute renal failure is always a complication of other pathological processes in the body.
Causes of acute renal failure
1. Shock kidney.Acute renal failure develops in traumatic shock with massive tissue damage, due to a decrease in circulating blood volume (blood loss, burns), reflex shock.It is observed in case of accidents and injuries, heavy operations, in case of damage and decay, and liver tissues of the pancreas, myocardial infarction, burns, frostbite, transfusion of incompatible blood, abortion.
2. Toxic kidney.ARF occurs when poisoning nephrotropic poisons such as mercury, arsenic, bertoletova salt, snake poison, insect poison mushrooms.Intoxication drugs (sulfonamides, antibiotics, analgesics), radiopaque agents.Alcoholism, drug addiction, substance abuse, occupational exposure to salts of heavy metals, ionizing radiation.
3. Acute infectious kidney.Developed in infectious diseases: leptospirosis, hemorrhagic fever.It occurs when heavily occurring infectious diseases involving dehydration (dysentery, cholera), and bacterial shock.
4. Obstruction (obstruction) of the urinary tract.Occurs when the tumors, stones, compression, ureteral injury, thrombosis and embolism of the renal arteries.
5. Developed with acute pyelonephritis (inflammation of the renal pelvis) and acute glomerulonephritis (inflammation of the glomeruli).
prevalence of acute renal failure
- 60% of all cases of acute renal failure associated with surgery or trauma.
- 40% of cases of acute renal failure in a patient develops the treatment in medical institutions.
- 1-2% - in women during pregnancy.
Symptoms of acute renal failure
In the initial period to the fore the symptoms of the disease, which led to the development of acute renal failure.This symptoms of poisoning, shock, of diseases.At the same time it begins to decrease the amount of urine (diuresis) initially to 400 mL per day (oliguria) and then to 50 ml per day (anuria).Nausea, vomiting, decreased appetite.There drowsiness, confusion of consciousness, there may be convulsions, hallucinations.The skin becomes dry and pale, with bleeding, swelling appear.Breath deep and frequent.Auscultated tachycardia, irregular heartbeat, increased blood pressure.Typically bloating, loose stools.
With time begun treatment, a period of recovery of diuresis.The amount of urine is increased to 5.3 liters per day.Gradually are all symptoms of acute renal failure.For full recovery must be from 6 months to 2 years.
Treatment of acute renal failure
All patients with acute renal failure in urgent need of hospitalization to the department of nephrology and dialysis, or in the intensive care unit.
decisive importance has begun as soon as possible treatment of the underlying disease, the elimination of factors that cause kidney damage.Since in most cases the cause is a shock, it is necessary as holding antishock measures as soon as possible start.If massive blood loss offset the loss of blood by introducing substitutes.If poisoning - derive from the body toxins by flushing the stomach, intestines, the use of antidotes.In severe renal failure conduct sessions of hemodialysis or peritoneal dialysis.
Stages of treatment of patients with acute renal failure:
- Eliminate all causes of decline in renal function, amenable to specific treatment, including correction and postrenal prerenal factors;
- Try to achieve a stable value of the volume of urine;Conservative therapy
- entering the body to reduce the amount of nitrogen, water, and electrolytes in such an extent that they are consistent with their quantities outputted;
- provide adequate patient nutrition;
- change the nature of drug therapy;
- ensure control over the clinical condition of the patient (measurement frequency of vital signs is determined by the condition of the patient, measuring the amount entering the body and emissions from it substances; body weight; inspection of wounds and places intravenous infusion; physical examination should be performed on a daily basis);
- ensure control of biochemical parameters (frequency determining BUN concentrations, creatinine, electrolytes and counting blood counts will be dictated by the condition of the patient, in suffering oliguria and catabolism of patients to determine these indicators should be on a daily basis, concentrations of phosphorus, magnesium and uric acid - less)
4. Run dialysis therapy
Some manifestations of acute renal failure can be controlled with conservative therapy.After you have corrected any violations vnutosudistoy volume of liquid, the amount of liquid entering the body must correspond exactly to the sum of its measured output quantity and insensible losses.Amount injected into the body of sodium and potassium should not exceed the measured output quantities.Daily monitoring of fluid balance and body weight makes it possible to determine whether not disturbed patient vnutosudistoy normal volume of liquid.In patients with acute renal failure receiving adequate treatment, body weight is reduced by 0.2-0.3 kg / day.A more significant decrease in body weight suggesting hypercatabolism vnutosudistoy or reducing the volume of fluid and considerable less suggests that the body receives excessive amounts of sodium and water.Since most drugs excreted, at least in part by the kidneys, it is necessary to pay attention ptalnoe use of medicines and their dosage.sodium concentration in the blood serum serves as a reference for determining the required amount of water added.Reduced sodium concentration indicates that the body has an excess of water, while an unusually high concentration indicates a lack of water in the body.
To reduce the need to provide, per diem catabolism intake of at least 100 g carbohydrate.Some recent studies have argued that the introduction of the central vein of amino acids and hypertonic glucose solution mixture improves the condition of patients and reduce mortality in patients suffering from acute renal failure developed after surgery or injury.Since parenteral administration of excessively large amounts of nutrient may be associated with considerable difficulties, this type of food should be reserved for patients prone to catabolism, in which you can not get satisfactory results using a standard injection of nutrients through the mouth.Previously, to reduce the level of protein catabolism and decrease the rate of increase AMC used anabolic androgens.Currently, such treatment is not applied.Among other measures, reducing the level of catabolism are timely removal of necrotic tissue, controlling hyperthermia and early initiation of specific antimicrobial therapy.
Patients with a weak degree of metabolic acidosis associated with acute renal failure, treatment is not indicated, except for those who bicarbonate concentration in the serum does not drop below 10 mEq / L.An attempt to restore the acid-base state by the urgent introduction of alkali can reduce the concentration of ionized calcium and cause tetany development.Hypocalcemia is usually asymptomatic and rarely requires specific correction.Hyperphosphatemia be controlled with 30-60 mL of oral administration 4-6 times per day of aluminum hydroxide, since the magnitude of the calcium x phosphorus product than 70 soft tissue calcification develops.Timely initiation of dialysis therapy will help control the increased phosphorus concentration in the serum of patients with severe hyperphosphatemia.If the patient did not reveal acute nephropathy caused by uric acid, the secondary hyperuricemia acute renal failure usually do not require the use of allopurinol.Reduction in glomerular filtration rate value does share filtered uric acid and hence deposition of uric acid in the tubules negligible.In addition, for unknown reasons, acute renal failure, in spite of hyperuricemia, seldom complicated by clinically gout.For early detection of gastrointestinal bleeding is important to closely monitor the changes in hematocrit and the presence of occult blood in the stool.If the hematocrit will decline rapidly and the rate of this decline will be inadequate degree of severity of renal failure, it is necessary to seek alternative causes of anemia.
congestive heart failure and hypertension are an indicator of the presence in the body of excess liquid and require appropriate action.It should be remembered that many of the drugs such as digoxin, are excreted primarily by the kidneys.As noted previously, not always resistant hypertension is caused by increased fluid volume in the body;in its development can contribute to such factors as giperreninemiya.In some cases, in order to prevent gastrointestinal bleeding in critically ill some successfully carried out a selective blockade of histamine-2 receptor (cimetidine, ranitidine), but the feasibility of this treatment for acute renal failure has not yet been investigated.To avoid infection and compromising the integrity of the anatomical barriers, avoid prolonged bladder catheterization, to conduct rehabilitation of the oral cavity and skin, the site of injection catheters for intravenous infusion and skin incision to perform a tracheostomy processing with aseptic and perform careful clinical observation.With an increase in body temperature of the patient must be carefully inspect it, paying particular attention to the state of the lungs, urinary tract, wounds and places the delivery catheter for intravenous infusion.
In acute renal failure often develops hyperkalemia.If the increase in the concentration of potassium in the blood serum of a small (less than 6.0 mmol / l), correct them only enough to exclude from the diet of all sources of potassium and maintain a permanent thorough laboratory control of biochemical parameters.If the concentration of potassium in the blood serum is increased to levels above 6.5 mmol / and especially if there will be any changes in the ECG, it is necessary to begin aggressive treatment of the patient.Treatment can be divided into emergency and routine forms.Emergency treatment involves intravenous administration of calcium (5.10 ml of a 10% calcium chloride solution is administered intravenously for 2 minutes under the control of the ECG), sodium (44 meq administered intravenously for 5 min) glucose and insulin (200-300 ml 20%, is administered intravenously over 30 min) glucose solution containing 20-30 units of regular insulin.Routine treatment includes administering kaliysvyazyvayuschih ion exchange resins such as sodium polystyrene sulfonate.They can be administered by mouth every 2-3 hours at dose.25-50 ml with 100 g of 20% sorbitol for the prophylaxis of constipation.On the other hand, a patient who can not take the drug orally, can be administered at intervals of 1-2 hours 50 g of sodium polystyrenesulfonate, and 50 g of sorbitol to 200 ml of water by retention enema.In the case of refractory hyperkalemia may need to hemodialysis.
Some patients with acute renal failure, especially in case of lack of catabolism and oliguria, can be successfully treated without using a dialysis therapy or a minimum in use.There is an increasing tendency to use dialysis therapy in the early stages of acute renal failure in order to prevent possible complications.Early (prophylactic) dialysis often simplifies the management of the patient, creating the possibility of more .liberalnogo approach to intake of appropriate amounts of potassium and fluids, and will help improve the patient's general state of health.Absolute indications for dialysis are symptomatic uremia (usually manifested by symptoms from the central nervous system and / or gastrointestinal tract);development of resistant hyperkalemia, severe acidemia or accumulation in the body of excess liquid is not amenable to medical exposure, and pericarditis.In addition, in many medical centers try to support pre-dialysis BUN and creatinine levels in serum of less than 1,000, respectively, and 80 mg / l.In order to ensure adequate prevention of uremic patients without symptoms of oliguria and catabolism of dialysis may be required only in rare cases, a patient whose condition is burdened catabolism and injuries, you may need to perform dialysis, per diem.Often, peritoneal dialysis is an acceptable alternative to hemodialysis.Peritoneal dialysis can be particularly useful nekatabolicheskoy patient with renal insufficiency, which is shown infrequent dialysis.To control the volume of the extracellular fluid in patients with acute renal failure, you can use a slow continuous blood filtration using highly permeable filters.Currently available commercially filters connected to the circulatory system via the arteriovenous shunt allow output of from 5 to 12 liters of ultrafiltrate of blood plasma per day without using the pump.Therefore, these devices apparently particularly useful for treating patients suffering and oliguria have increased volume and extravascular fluid hemodynamically unstable.
Power of such patients is very important.
Nutrition in acute renal failure
Hunger and thirst dramatically worsen the condition of patients.Assign protein diet (no more than 20 g of protein per day).The diet consists mainly of carbohydrates and fats (water porridge, butter, yogurt, bread, honey).If it is impossible meal intravenous nutrient mixtures, glucose.
Complications of acute renal failure
in initiating and supporting the phases of acute renal failure, impaired excretion of urinary nitrogen metabolism of food, water, electrolyte and acid.Intensity of changes taking place at the same time to the chemical composition of the blood, depends on the presence of oliguria, catabolic state in a patient.We do not suffer from oliguria patients had higher levels of glomerular filtration rate than in patients with oliguria, and therefore in the first urine excreted greater nitrogen metabolism of food, water, and electrolytes.Therefore, the chemical composition of blood disorders in acute renal failure in patients not suffering from oliguria are usually less pronounced than that of suffering oliguria.