• Nephrology: Kidney Dialysis

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    For almost half a century in many countries, patients with terminal forms of chronic kidney failure can continue a relatively autonomous life for several years. And earlier it seemed impossible. The reason for this was chronic dialysis of the kidneys, without which they could not survive a few days.

    Problems of chronic kidney failure and hemodialysis

    In the World, there are about 500-600 thousand people with end-stage renal failure( chronic renal failure), which several times a week needs dialysis of the kidneys. Otherwise, within a few days they would have died.

    However, the incompatibility of such patients to the proportion of the population differs in different regions of the Earth. For example, in developing countries in Africa and South-East Asia, people with this pathology meet no more than 1.0-1.5 cases per 100 thousand of the population. In Europe and North America, this figure is 10 times more important. The frequency of newly registered cases is approximately the same. Everything is explained very simply. In developed countries, hemodialysis is very common about the public, rather than in developed countries. Therefore, most of the patients do not survive the next dialysis session.

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    This is important! The essence of the method is quite simple. It consists in purifying blood from low-molecular compounds. When hemodialysis, such compounds are creatine, urea, uric acids, indoles and some other metabolic products that are normally removed from the body by the kidneys. But with terminal CRF, they can not already perform these functions.

    Procedure for hemodialysis

    Hemodialysis is a special dialysis method and is used for blood purification. It has been successfully used for almost 50 years. This method is hardware, and produced with the help of the so-called "artificial kidney."Over the years, he has undergone many changes. But the principle of work, which was presented more than 150 years ago by the Scottish scientist T. Graham, remains unchanged. Blood, passing through special membranes. They share blood and a special dialysis solution. As a result, due to the action of the laws of osmosis, various low-molecular compounds come out of it.

    During repeated blood passage, various substances related to proteins also leave. In addition, dialysis of the kidneys helps to restore the normal balance of red blood cells due to the fact that the primary dialysate contains their specific concentration. At the output is completely cleared blood. She goes back to the bloodstream.

    To ensure constant access to the patient's circulatory system, a specially implanted fistula is used. It connects the large vessels of the limb. In many countries, they make one more of the upper limbs. It connects the radial artery and one of the large subcutaneous veins of the forearm. Each session in the fistula inserts special sticks. One, taking blood to the apparatus, is directed toward the artery. Friend, because there is a "return", is directed towards the vein. On average, one session of hemodialysis lasts 3 hours. Its repetition is necessary once in 2 days.

    But there are other programs:

    • Short. Daily for 2 hours.
    • Twice a week for 4 or 5 hours.

    All depends on the individual characteristics of the body and the functionality of the hospital. The last factor is the economic factor and transport accessibility.


    Used at the beginning of its development as a means for removing uremic coma caused by a large amount of nitrogenous compounds( urea, uric acid) due to renal failure, dialysis of the kidneys now has a rather wide range of indications:

    • Acute renal failure and uremic coma.
    • Terminal stage of chronic renal failure. Usually, program hemodialysis( permanent and systematic) is indicated with a decrease in renal function by 80-85%.This is clearly seen from laboratory tests. Creatinine in the blood plasma is greater than 800 mmol / l, urea more than 20 mmol / l, blood potassium more than 6.5-7 mmol / l.
    • Poisoning by medicinal and poisonous substances. But only by those, offices can move through the dialysis membrane.
    • Acute alcohol poisoning, up to coma.
    • Severe disturbances of electrolyte balance of blood plasma.
    • As a measure of dehydration under certain life-threatening conditions.

    In some clinics, dialysis is used to reduce antigen-antibody complexes. But since this is only a temporary phenomenon, hemodialysis is neither economically nor physiologically justified. So for example is done with some systemic diseases. For example, systemic lupus erythematosus, scleroderma.

    Complications of hemodialysis

    The average life expectancy of patients on programmed hemodialysis is more than 10-15 years. Although there are sporadic cases, when patients lived more than 20 years. In any case, dialysis is associated with the development of a number of complications.

    All of them are conditionally divided into early and late. The first are associated with the very procedure of hemodialysis. The second group of complications is the result of the course of chronic renal failure. Also, the latter category includes complications arising after several years of procedures.

    Early complications:

    • Reduced blood pressure or hypotension. Occurs in every third patient in the first year of the procedure. It can be associated with a high rate of ultrafiltration in the apparatus and rapid removal of fluid from the body.
    • Neurological disorders: imbalance, dizziness, up to nausea and vomiting. Arise as a result of fluctuations in blood pressure.
    • Syndrome of water-electrolyte disorders: weakness, headaches, nausea, convulsions. They are the result of imbalance of ions in the dialysis solution and blood in the "stroke".
    • Allergic reactions to the dialysis solution and anticoagulants used during the procedure.
    • Acute hemolysis and the development of anemia. As a result of the destruction of erythrocytes in ultrafiltration and electrolyte imbalance.

    Late complications:

    • Infectious. Hepatitis and some other nonspecific infections.
    • Exchange violations. Among them in the first place is the development of amyloidosis of the kidneys.
    • Anemia. As a result of the absence in the blood of erythropoietin, which is normally produced by the kidneys.
    • Development of arterial hypertension. It also occurs because of the existing chronic renal failure. But its mechanism is associated with chronic nephron ischemia.

    Nevertheless, despite the complications and development of life dependence, dialysis is the only way out for a certain category of patients. For the time that they are on programmed hemodialysis, a small part survives to kidney transplantation.

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