Hemodialysis - a method of extracorporeal blood purification from the exchange (mainly nitrogenous bases) products through an artificial semipermeable membrane apparatus "artificial kidney".
Indications for hemodialysis
Indications for hemodialysis:
- acute and chronic renal failure
- poisoning by different poisons
- poisoning medicinal substances
- severe disorders of blood electrolyte composition
In chronic kidney disease indication forhemodialysis is kidney failure that does not respond to conservative therapy, and proceeds to the terminal stage of the disease. Hemodialysis is a method that allows you to extend the life of the patient, when fully exhausted their own possibilities of maintaining a satisfactory condition of the body.
The symptoms of uremic intoxication arisingdue to increased concentration in the blood of nitrogenous bases are dyspeptic disorders (nausea, vomiting), the smell of urine in the breath, anemia, increased bleeding, dry and icteric staining of the skin, itching, sleep disturbances, and others. The absolute sign of decompensated uremia and indications for hemodialysis considered pericarditis. Hemodialysis is required and due to the temporary deterioration in renal function, for example due to the aggravation of the primary disease.
Contraindications to the use of hemodialysis
Application software hemodialysiscontraindicated in patients with malignant tumors, nervous system lesions (hemiplegia), mental disorders, some contagious (infectious) infections. Unfavorable conditions for hemodialysis are untreatable hypotension, ongoing internal bleeding and hemophilia.
The apparatus "artificial kidney"
Hemodialysis is performed using apparatus"Artificial kidney". At the heart of its operation are dialysis principles allows to remove from the patient's blood substance plasma of low molecular weight (electrolytes - sodium, calcium, potassium, products of nitrogen metabolism - urea, creatinine, uric acid, etc.), And partly to ultrafiltration whereby derived excess water and toxic substances with higher molecular weight.
Despite the variety of designs, allartificial kidney devices have a circuit composed of the dialyzer and, device for mixing and conveying the dialyzer dialysate perfusion device that provides advancement through a blood dialyzer, and monitor.
Device as a major part of the machine. The most important functional element of it is semi-permeable dialysis membrane that divides the interior of the dialyzer into two parts for the blood and solution.
Dialysate is close to a plasma ultrafiltrate and is designed to recover the salt uremic disorders and blood acid-base composition.
During hemodialysis procedure the doctor usesaccess for hemodialysis blood through the device. The function unit is to withdraw from the blood and regulate the metabolic products of plasma chemical balance. After that, the purified blood is returned back into the bloodstream through the hemodialysis access. Creating access - the port, is a small operation. There are two types of ports. The most common access - fistula (a connection to the artery vein) and the stent (artificial tube that connects an artery to a vein).
A week after the operation the fistula begins"ripen". It increases in size, it may look like a cord under the skin. The entire process usually takes 3-6 months. Matured fistula should be broad and flexible enough to be easily put into her dialysis needles.
The stent can be used in 2-6 weekshow will it engraftment. Fistula usually preferred, since the patient's own tissues are used for its formation, which are more resistant to infection than the stent. However, when vein occlusion or a small diameter of the stent is preferred.
When used as fistula and stentthe connection between an artery and a vein increases the volume of blood flow through the vein. In response, Vienna stretched and becomes elastic. With this vein extends through a larger volume of blood, which increases the efficiency of hemodialysis.
Before the artificial kidney treatments sterilized and washed with canister connect dialysate.
The duration of hemodialysis is approximately 5-6hours. In the course of the blood pressure treatments are permanent supervision of a physician, the patient's heart rate and other indicators, as well as the state of the vascular access. After the procedure is applied to the area of aseptic (sterile) dressing.
Complications of hemodialysis
The kidneys are involved in the work of many systemsso the body when the kidneys stop working, the function of other body systems also disrupted. Unfortunately, this leads to disruption of the entire organism and affects the patient's condition. Complications of hemodialysis:
- bone disease
- increase the level of potassium in the blood
- damage to the nervous system
Anemia means that reduces the amount of blood in erythrocytes (red blood cells), which are transferred via the hemoglobin oxygen to tissues. Among the causes of anemia in dialysis release:
- deficiency of erythropoietin, a hormone produced by healthy kidneys to stimulate formation of erythrocytes in the bone marrow
- blood loss due to bleeding, dialysis and blood sampling
- reduced intake of iron and vitamins with the food of the diet, poor absorption of iron in the intestine or the loss of iron and vitamins during the dialysis
Diseases of bones
In patients with end-stage renal phasefailure disturbed absorption of calcium, phosphorus, and vitamin D. This leads to increased bone fragility (renal osteodystrophy). As a result of these changes appear osteomalacia (bone destruction) because the kidneys can not convert vitamin D to a form which facilitates calcium absorption. An imbalance in the blood calcium and phosphorus compounds leads to deposition in the heart, lungs, skin, joints and blood vessels. The deposition of calcium in the skin leads to inflammation, development of painful skin ulcers (calciphylaxis).
Increased blood pressure
If used together with kidney disease hashigh blood pressure, it is necessary to limit the use of salt and fluids. If hypertension is left untreated, damage to the blood vessels can lead to stroke or heart attack.
Pericarditis, an inflammation is called a shell,covering the heart - the pericardium. The main reason - lack of dialysis. There is accumulation of fluid around the heart, impaired ability of the heart to contract and reduced blood ejection.
Increased blood levels of potassium (hyperkalemia)
Patients who are on hemodialysis, is recommended diet low in potassium. Increasing blood potassium can lead to heart failure.
Damage to the nervous system (peripheral neuropathy)
Peripheral neuropathy manifests violationsensitivity in the hands, feet and legs. This occurs for various reasons, among them the accumulation of waste products of the body, diabetes, lack of vitamin B12 and other causes.
Prevention of complications during hemodialysis
The final decision on the duration of treatment and prevention of complications the patient is taking. By the measures of prevention of complications include:
- prevention of infectious complications in compliance with hygienic requirements for intravenous catheter care
- adherence to the assigned diet doctor
- eating the recommended amounts of liquid
- receiving prescription drugs
- according to the treatment plan undergo hemodialysis in specialized centers
- inform medical staff about all the symptoms of complications
If the treatment of the terminal phase of renal failure requiring hemodialysis, for the prevention of complications should implement the recommendations of the appointment and the medical staff.