What is hemodialysis for? Hemodialysis - what is it and at what creatinine is it prescribed? Carrying out hemodialysis in stationary conditions

Every year, tens of thousands of new cases of chronic renal failure - chronic renal failure - are diagnosed worldwide. The disease has a chronic progressive course, and there are not many ways to effectively treat it. One of them is hemodialysis, a method of treatment that successfully replaces healthy kidneys and allows you to cleanse the blood of substances that are unnecessary and toxic to the body. Despite the advantages, the procedure has its own complications. Let's try to figure out how long life can last on hemodialysis, how often it should be done, and what patients with chronic renal failure need to know.

When blood purification is indispensable

Hemodialysis is a blood purification that takes place outside the kidneys. The main purpose of the procedure is to maintain the constancy of the internal environment, as well as to rid the body of:

urea - the end product of protein metabolism in the body;
creatinine - a substance formed during active energy metabolism in muscle tissue;
substances poisoning the body (for example, strontium, arsenic, plant and animal poisons);
medicines - salicylic acid preparations, barbiturates, sedatives, sulfonamides, etc.;
ethyl alcohol (alcohol);
"Extra" electrolytes (potassium, sodium) and fluids.

The main indications for hemodialysis are:

chronic renal failure with symptoms of uremia (occurs when the functional activity of the kidneys decreases to 20-30%);
acute renal failure arising from inflammatory diseases (pyelonephritis, glomerulonephritis), acute urinary retention, crash syndrome, etc.;
poisoning with poisons, toxic substances, alcohol, drugs and medicines;
overhydration - "water poisoning" of the body;
violations of the ionic composition of blood with extensive burns, dehydration, prolonged intoxication, intestinal obstruction.

Although in many of the conditions listed above, the patient's kidneys partially retain their functional activity and do not require hemodialysis, in some cases only this procedure can save the patient's life. Clear criteria for the need for hemodialysis include:

oliguria (daily urine output is 500 ml or less);
kidneys filter less than 200 ml of blood within 1 minute, their functional activity is lost by 80-90%;
the level of urea in the biochemical blood test exceeds 33-35 mmol / l;
plasma creatinine levels above 1 mmol / l;
potassium concentration - more than 6 mmol / l;
bicarbonate level - less than 20 mmol / l;
growing signs of uremia, edema of the brain and internal organs.

The principle of operation of the hemodialysis machine

Hemodialysis is a relatively "young" treatment technology: it recently turned 40 years old. Over the years, it has become widespread throughout the world and has even grown to a separate branch of medicine.

The apparatus of the "artificial kidney" is simple and consists of two interconnected systems:

for processing (purifying) blood;
for dialysate preparation.

The patient is taken venous blood, which is fed through a soft catheter to the filtration system. The main component of the filtration system is a semi-permeable membrane made of cellulose or synthetic materials. Pores of a certain size allow the separation of substances harmful to the body, as well as excess fluid and plasma with proprietary elements. The purified blood flows back to the patient, and the dialysate with unnecessary substances is disposed of. On average, this procedure lasts 4-5 hours and is carried out in an intensive care unit.

During hemodialysis, the doctor carefully monitors the patient's blood pressure and other vital signs. In case of a sharp deviation from the norm, the procedure is suspended. Before blood sampling, the patient is given heparin or other antiplatelet agents that prevent the formation of blood clots that invariably form on the vascular wall when using a soft catheter.

Note! Today there is a possibility of carrying out hemodialysis at home. To do this, the patient needs to purchase a portable "artificial kidney" apparatus, the cost of which ranges from 15-25 thousand dollars, and to undergo training in the independent use of the device.

The distinctive features of home hemodialysis include:

convenience and comfort for the patient;
no risk of infection with blood-borne infections (HIV, hepatitis B, C);
lack of medical supervision, the possibility of complications of the procedure.

The negative effects of hemodialysis

Hemodialysis is a procedure that is quite traumatic for the body. It can cause the following side effects in the patient:

loss of essential mineral salts, electrolyte disturbances;
muscle pain, cramps, spasms provoked by a lack of sodium, magnesium, chloride, potassium and other elements in the blood;
pathology of heart rhythm, atrial fibrillation, extrasystole, right or left bundle branch block;
hypotension;
anemia caused by the destruction of red blood cells during the procedure;
bone pain.

How long does this therapy last?

The main method of symptomatic treatment of chronic renal failure is renal dialysis: how long patients live with him largely depends on the course of the pathology and the characteristics of the organism.

If the hemodialysis schedule is observed (with a persistent decrease in the functional activity of the organ - usually 2-3 times a week) and the absence of progressive signs of cerebral edema, the patient feels good and can maintain his usual lifestyle for years.

On average, the life expectancy of patients with chronic renal failure who regularly undergo blood purification is not inferior to that of healthy people. Hemodialysis can be performed until a donor kidney is found for the person. Sometimes it takes years: on average, 1000 transplant operations are performed in Russia annually, while there are at least 24 thousand patients awaiting their turn.

Every hemodialysis patient should understand how important the blood purification sessions are for him. Compliance with medical recommendations and regular visits to the clinic, where the "artificial kidney" apparatus is located, will allow a patient with chronic renal failure to live a long and active life, and patients with acute disorders will quickly return to health.

It is known that life expectancy directly depends on the condition of the kidneys. But only the chronically ill really knows.

His body works in the mode of ever-increasing poisoning by the wastes of its own metabolism, because the organs of purification and excretion cannot cope with their task.

Smells of acetone, vinegar and other poisons in the air he exhales. They are clearly read by others among other unpleasant odors, but give only a distant idea of what is happening inside the body at this time.

The skin connected to the evacuation of toxins also exudes a waste of no less strength.

And then extremely clogged biological filters fail. They refuse to serve, causing the sick person to despair.

But not with someone who already has experience in hemodialysis. Such a patient does not bring the matter to a critical point - he knows: it's time to visit the dialysis center.

What is kidney dialysis?

The term "artificial kidney" apparatus is widely known. But for those who have questions for the kidneys, the unit saves lives. Or extends it for years.

An artificial kidney machine is a construction (machine) that makes renal hemodialysis possible.

The literal translation of the term "dialysis" means: separation or fractionation. Therefore, the literal answer to the question: kidney dialysis, what is it - means a division into good and bad. Thanks to the machine, which takes over the function of failing kidneys, the good that the body needs is returned to it, the obscene is removed.

Kidney hemodialysis is an artificial purification of the blood from toxins. During the procedure, it leaves the body for a short time in order to return to it cleansed.

“Leaving” does not mean at all that it is merging from the bloodstream somewhere - it continues to circulate, driven by the heart.

But some interference is made in its movement - the "artificial kidney" apparatus, or hemodialyzer, is connected.

Blood comes into it from:

punctured vein, or
direct arteriovenous connections, or
graft- a synthetic tube that mimics the saphenous vein.

Leaving it already cleansed, it returns to the bloodstream through punctured vein.

The entire volume of blood is passed through the apparatus many times. The process is carried out either in sessions of 4-5 hours, or runs around the clock constantly. Depending on the pathology option, needs (and financial capabilities) of the patient, constructions are used:

stationary;
portable, body-worn, weighing 4-7 kg.

All this time, the movement of blood does not stop for a moment - it moves by contractions of the heart, which continues to perform its function as a pump. The procedure is exactly the same as a natural process. Only in the middle of the blood path from heart to heart there is a kidney constructed by man.

A short excursion into chemistry and physics

An illustration of the process is the purification of smoking smoke in a hookah, where it is passed through water and then consumed.

Kidney hemodialysis uses 3 physical and chemical laws, which can be realized by the diffuser - filter apparatus, which is a membrane with selective permeability.

Process diffusion happens through a membrane between the hemodialysis solution and the patient's blood. It allows you to extract compounds with given molecular weights from the blood.

In accordance with the pore diameter and other clear parameters of the filter membrane, these are electrolyte ions and proteins of the β2-microglobulin category.

But in parallel there is (possible) and the reverse process - the transition from the solution for hemodialysis into the blood of electrolytes and high molecular weight compounds. Considering this fact, a given concentration of electrolytes is maintained in the dialysate solution, which allows maintaining the salt balance in the patient's blood. To prevent the penetration of microbial poisons and other toxins into the patient's blood, the working solution is systematically cleaned.

Insufficient perfection of filtering membranes does not yet allow extraction from blood toxins, chemicallyassociated with proteins, as well as their hydrophobic fractions.

Removal of hydrophobic fractions of toxins occurs using the same filter due to the process convection, possible due to the presence of osmotic pressure. It arises from the difference in the concentration of solutions on different sides of the membrane.

The blood pathway during hemodialysis is lengthened and difficult. Therefore, to facilitate filtration through the membrane, the hemodialyzer operates its own pump... Due to its work, pressure is created by blood on the surface of the membrane, and the process is started ultrafiltration - removal of excess water from the body.

The rest of the design is:

blood pipeline;
a dialysate solution propulsion system and
control system for multiple parameters of both environments.

To prevent blood clotting, it is used anticoagulant(most often heparin).

Summary: since each chemical compound has a certain electric charge, specific gravity, chemical and spatial structure, kidney hemodialysis is electrochemical sorting on the beneficial and harmful to the body with the regular removal of the harmful with the help of the apparatus.

As a result of using a hemodialyzer, the following occurs:

extraction from the blood of most nitrogenous compounds that are not chemically bonded to proteins;
ridding the body of edematous fluid.

When and to whom is hemodialysis of the kidneys indicated?

If recently intravenous injection was equivalent to surgery, then hemodialysis of the kidneys is essentially an operation.

Therefore, before starting hemodialysis, not only the indication for the procedure is taken into account, but also factors that can complicate (make it impossible) the course of the operation - contraindications.

The main testimony for the hemodialysis procedure there are options:

acute renal failure;
chronic renal failure;
poisoning with medicines or poisons (subject to their ability to pass through the membrane of the hemodialyzer);
severe disorders of the electrolyte balance of the blood;
alcohol intoxication;
life-threatening overhydration (category of pulmonary edema, brain), which cannot be eliminated by other (conservative) methods. In the latter version, to improve the condition, we use the method isolated ultrafiltration.

The basis data are used to prescribe the hemodialysis procedure laboratory and instrumental diagnostics:

indicators of the level of urea in the blood;
Ultrasound, MRI of the kidneys.

Contraindications

Kidney hemodialysis has contraindications both relative and absolute.

conditions with the possibility of massive bleeding (and,).

The second is the options:

mental disorders and pathologies (epilepsy, schizophrenia, psychosis);
malignant neoplasms in an incurable stage (for example: throat cancer in stage 4);
blood diseases (,);
severe neurological pathologies;
in patients over 70 years old or senile (over 80 years old) age;
a combination of two (or more) significant pathologies such as advanced atherosclerosis, diseases with respiratory failure;
drug addiction and alcoholism without the likelihood of rehabilitation.

About security guarantees

In addition to the emergence of a number of social and financial issues in front of the patient (the cost of one course reaches 1.5 million rubles, because for 1 session the volume of dialysate is about 120 liters), the opportunity for it should not be discounted. complications during this mini-operation.

Since the kidneys not only participate in the cleansing of the internal environment of the body, but are also complex hormone-producing formations, risk of occurrence complications as:

arterial hyper- or hypotension;
hyper- or hyponatremia;
convulsive syndrome or seizure of epilepsy;
air embolism or thrombus formation;
weakness, dizziness, nausea, vomiting, or heart rhythm disturbances due to changes in intracranial pressure;
an allergic response to the components of the dialysate solution.

In the age of disposable catheters and syringes, a natural question arises: is it not dangerous to use a device that simulates the work of the kidneys? Will any infection of the hepatitis or HIV / AIDS category be transmitted through the device?

Unintentional infection the patient during the preparation of the procedure is unlikely, but it is also possible - it all depends on the state of immunity and the general status of the body. Indeed, with the loss of kidney function up to 85% (which is the basis for treatment), the state of the internal "climate" often changes irreversibly.

"Artificial kidney" - the only method of blood purification?

After receiving an answer to the question: kidney dialysis, what is it - it would be unfair not to get acquainted with alternative methods of blood purification.

In addition to cleansing with an artificially constructed kidney, there are other methods based on the same principle of a restricted membrane.

Peritoneal dialysis

At peritoneal dialysis the role of the filter is performed by its own peritoneum the patient to be cleaned when intestinal dialysis the same function is performed by colon wall.

Although both methods are less effective, they make it possible to achieve a satisfactory result when hemodialysis is contraindicated.

In addition, they differ in the lower cost of ingredients and equipment.

The method of detoxification hemosorption is somewhat different. It offers the purification of the patient's blood by its perfusion through a detoxifier - a special column-filter made of activated carbon or another type of sorbent.

Applied in a specialized hospital, the technique, being also cheaper than hemodialysis, has its own field of application in the removal of a number of toxic substances from the body.

After solving a number of technical issues (such as replacing a sorbent of a simple composition with ion-exchange resins), this method promises great prospects.

In the case when all options for detoxification have been exhausted, the patient has the last chance to survive - kidney transplantation.

On the need for a regimen and diet for hemodialysis

In view of the load on the body, which increases both with all options and in the process of its apparatus treatment, there is a need for therapeutic nutrition.

Due to the forced circulation of blood and aggressive intervention in the existing balance of metabolism, part of the amino acids, minerals and vitamins, the supply of which should be replenished by the consumption of high-grade protein foods, predominantly of animal origin.
In the presence of arterial hypertension, it is prescribed completely salt-free diet.
Due to a sharp decrease in the volume of diuresis (oliguria of any genesis: with cardiac, renal, hepatic insufficiency), consumption water is also sharply limited.
Due to a disorder of excretion in the urine potassium it is necessary to reduce the consumption of foods rich in this substance in order to avoid its overabundance in the body.
Balance disorder phosphorus and calcium - minerals working in close conjunction with potassium, there is a need for forced correction of their content in the blood.
Renal failure causes greater caution about compounds aluminum... This microelement, which gets inside when using aluminum dishes or is part of complexes of multivitamins, becomes very toxic under the changed new conditions. Therefore, rash behavior and non-compliance with the diet can become, damage to bone tissue and neurological pathology.

For drug correction of the level of all of the listed microelements, repeated laboratory diagnostics are required.

Forecast and conclusion

Deciding on certain measures for the patient's diet and lifestyle remains the prerogative of the attending physician or medical council, while the patient must coordinate all his actions with a specialist doctor (nephrologist or urologist).

Kidney dialysis (hemodialysis) - what is it

This procedure consists in purifying human blood from harmful waste products of the body and artificially stabilizing the water-electrolyte balance.

Dialysis cannot heal the kidneys or slow down inflammatory or regressive processes in the kidney tissue. Its purpose is to maintain the performance of all body systems until the moment when the patient's excretory organs can again perform this task or before the transplant is performed.
Very often, in the presence of a number of indications and / or in the impossibility of transplantation, the procedure has to be carried out for life.

Dialysis is a general concept, based on the methodology, hemodialysis and intestinal dialysis are distinguished. However, the last two types are less effective and are used, as a rule, in the presence of contraindications to hemodialysis, or as a temporary measure.

It is not obvious, but the procedure requires psychological preparation. The question here is not so much how many people live on kidney dialysis, but how ready a person is for this procedure and possible restrictions in everyday life after it (diet, medication).

Indications for hemodialysis procedure

Hemodialysis sessions, as a necessary measure to maintain life, are prescribed for acute and chronic renal failure to cleanse the kidneys from endotoxins, but they can also be recommended for the following pathological conditions:

poisoning with products containing alcohols;
the presence in the body of poisons of plant or chemical origin;
overhydration (excess fluid) that does not respond to drug treatment and is life-threatening (pulmonary or cerebral edema);
violation of water and electrolyte balance in the body;
an overdose condition as a result of a violation of the medication regimen.

It is worth noting that the attending physician can only recommend hemodialysis, the decision is made by the patient himself, who should be provided with comprehensive information about possible side effects.

How many live on such a procedure

Not so long ago, the diagnosis of chronic renal failure left no chance of survival. , prescribed for life, allows you to support the body of such patients. On what period? And here everything is not so simple.

Each patient asks the question, how long do they live on hemodialysis according to modern statistics? The often voiced term is 15 years. The patient's psychological attitude is very important here - you need to show a little will, without this the process of adaptation to the procedure may be delayed, someone may need the help of loved ones - and this is also not forbidden.

Also, one should not forget that quite recently we could only talk about 3 or 7 years of life, however, the equipment is being improved, the procedure itself becomes more streamlined and during his life on hemodialysis the patient may have the opportunity to carry out transplantation - after it is necessary in dialysis will simply disappear.

Do not forget that medicine does not stand still and can provide patients with drugs to compensate for some "weakening" of the body after the dialysis procedure.

So there is no need to despair and remember that earlier (and now - even more so) there were cases when people lived on this procedure for decades.

Complications of dialysis affecting life

The human body is not always able to adequately respond to this not entirely natural procedure. In doing so, it is important to separate the unwanted symptoms associated with adaptation to dialysis and systemic problems.

The first is a temporary phenomenon, they may require only symptomatic correction, and, as a rule, fade away as you get used to the procedure.

More serious side effects of the sessions include:

pressure surges and heart rhythm disturbances;
anemia;
epileptic seizures;
diseases associated with the spread of microbial flora in the body - sepsis, endocarditis, osteomyelitis;
large-scale violation of water and electrolyte balance.

In these cases, the following measures will help:

constant monitoring and correction of a number of indicators;
adequate drug therapy;
adherence to diet and.

Also, the cause of complications may be conducting sessions in the presence of contraindications:

mental disorders or tendency to them;
tuberculosis;
oncological diseases accompanied by metastases;
arterial hypertension and pre-stroke condition;
a number of blood diseases (anemia with impaired formation of erythrocytes, cancer, clotting abnormalities);
diabetes.

At the same time, if the likelihood of death is high, the procedure can be carried out even if there are contraindications.

Unfortunately, human and technical interference in the procedure cannot be ruled out. As a result, the following undesirable phenomena may occur:

equipment malfunctions;
incorrectly selected dialysate composition;
the ingress of air particles into the bloodstream;
obstruction of the hardware catheter;
introducing infection into the bloodstream during dialysis or preparation for it.

At the same time, subject to the rules for operating the equipment and the proper level of qualifications of personnel, the likelihood of such cases is very small.

Factors helping to prolong life

Undoubtedly, the severity of the underlying disease and the general condition of the body play an important role. But the following points can affect life expectancy:

In order to start applying this technique, you should not wait for the complete one. If there are indications with procedures, it is better not to delay.
You should adhere to the session schedule prescribed by your doctor.
You need to be careful about the choice of medications used, and, if possible, the clinic in which the sessions are held.
Do not keep silent about eating disorders or emerging ailments - this information may be important for correcting the regime of procedures.
You will need to make changes in your daily diet - the food should be rich in proteins and contain a limited amount of salt, some spices and water. It is advisable to avoid canned food, smoked meats and foods rich in potassium. Diet is a prerequisite, especially for lifelong dialysis.

It's important to know! Under such a condition as lifelong hemodialysis of the kidneys, the role of diet is so great that life expectancy can directly depend on it.

Simply put - you need to understand that hemodialysis, cleansing the body and working "instead of the kidneys", is still not a natural process. Therefore, it is important to monitor your health in general and listen to your doctor in all matters related to supportive care. Then there is an opportunity to live a full life for several decades.

Hemodialysis is a procedure for extrarenal blood purification from various toxins, metabolic products, and excess water. In addition, during the procedure, it is possible to correct the electrolyte balance. The procedure is carried out using the "Artificial kidney" apparatus. The method is based on the use of special membranes with selective permeability. On one side of the membrane, blood flows, on the other, a dialysis solution capable of absorbing endo- and exotoxins.

The membranes used can differ in their selectivity. Some of them are even capable of passing some proteins. Also, the properties of the dialysis solutions used may differ in their properties, which are able not only to absorb toxins and metabolic products, but also to replenish the lack of minerals in the patient's blood.

Indications for hemodialysis:

poisoning;
drug overdose;
pronounced deviations in the electrolyte composition of the blood;
pronounced excess of fluid in the body, which is not eliminated by conservative therapy: pulmonary edema, cerebral edema.

Complications:

lowering blood pressure;
convulsions;
infectious complications;
nausea, vomiting;
air embolism;
dialysis syndrome - develops under the condition of a rapid decrease in the osmotic pressure of the blood and is manifested by impaired consciousness such as stunning, convulsive seizures;
cardiac arrhythmia - develops with rapid calcium and sodium in the blood;
allergic reactions to the components of the membrane used in the apparatus.

Contraindications:

absolute:

schizophrenia;
epilepsy;
running oncological processes;
age more than 80 years (if the patient has diabetes mellitus - more than 70 years);
severe diseases of the nervous system;
the presence of 2 or more severe concomitant diseases: malignant tumors, coronary heart disease with a history of heart attack, heart failure; severe atherosclerosis with decompensated peripheral vascular occlusion, liver cirrhosis, COPD;
alcoholism, drug addiction, vagrancy.

relative:

pulmonary tuberculosis, proceeding in an active form;
risk of bleeding: gastric ulcer and duodenal ulcer, Melory Weiss syndrome, uterine fibroma ...

Diet for hemodialysis

The main goal of adhering to a diet is to reduce the intake of foods, the metabolism of which leads to a rapid increase in endotoxins. Let's take a look at the basic rules that should be followed by patients on continuous hemodialysis:

Limiting fluid intake. Usually, the volume of fluid consumed per day should fluctuate within the following limits: daily urine output + 500-800 ml. At the same time, the total weight gain between hemodialysis sessions should not exceed 2-2.5 kg. It should be borne in mind that with an increase in fluid loss through the skin and respiration (hot summer, high body temperature), the amount of fluid consumed can be increased.
Limiting salt intake (6-8 g of salt per day) or completely salt-free diet.
Limiting the use of foods containing a large amount of potassium: bananas, citrus fruits, dried fruits, some vegetables (especially potatoes), natural juices, herbs, bran, oatmeal, nuts, chocolate, cocoa. On average, the amount of potassium consumed per day should not exceed 2000 mg.
Limited consumption of foods rich in phosphorus (fish, cheese ...);
It is advisable to eat food that is sufficient in animal protein and energy (calories).

The listed rules are general, but individual characteristics should be taken into account and the recommendations of the attending physician should be carefully followed.

How is hemodialysis performed?

Creation of conditions for normal blood flow to the "Artificial kidney" apparatus. This requires a direct connection between the artery and the vein:

Fistula creation is a surgical connection between a vein and an artery, usually in the forearm.
The use of a graft - in this case, the communication between the artery and the vein is realized through a synthetic tube. Usually, graft placement is performed at the initial stages of hemodialysis, when the fistula is not yet formed. The downside is the higher likelihood of complications.
Catheterization of large veins in the neck, chest, or thigh. Usually this method is used for urgent hemodialysis when there is no time to create a full fistula.

The doctor calculates which membrane and dialysate to use. This is determined by the disease, the degree of preservation of the functioning of the kidneys, as well as the severity of intoxication and electrolyte imbalance.
Also, the doctor determines the required frequency and duration of the procedures, which also depends on the residual renal function.

Usually the procedure is carried out 3 times a week, and the average duration is 4-5 hours. Most often, procedures are performed on an outpatient basis, i.e. in a hemodialysis department. However, there are portable (home) dialyzers that allow shorter but daily procedures. Such devices significantly improve the patient's quality of life, reduce the likelihood of contracting viral hepatitis, and allow more freedom to change their place of residence and even travel.

Patients suffering from various renal pathologies are well aware of hemodialysis what it is. It is used to cleanse the blood from accumulated harmful substances. This procedure is long and exhausting. In addition, a person should plan his entire daily life taking into account the need for hemodialysis. But nevertheless, in cases of complete kidney failure and in the absence of conditions for transplantation, it remains the only way to save a person's life. Therefore, many patients live on hemodialysis for a long time. When hemodialysis is prescribed and what it is, how often it is performed, will be described below.

What is kidney hemodialysis? The idea of an "artificial kidney" apparatus, which is used for extrarenal blood purification, originated in the middle of the 19th century. The basics of hemodialysis are based on the diffusion principle. In the case of liquids, diffusion can be described as the process of movement of substances in a solution through a special membrane from a solution with a high concentration to a less concentrated solution.

Since its inception, the apparatus has been repeatedly modified and today it is a compact device consisting of several filters and a porous membrane. The work on its improvement does not stop. Currently, portable modifications have been developed, and even those whose components are implanted into the patient's body instead of diseased kidneys.

The principle of operation of the device is that it is connected to the patient's circulatory system. In hemodialysis, blood is on one side of the membrane, and on the other there is a special solution called dialysis. Due to different concentrations from the blood through the membrane, various substances are excreted into it, which in a healthy person are filtered by the kidneys. The membranes used in the device can have different characteristics and allow the diffusion of various substances - from metal ions to protein molecules that are much larger in size. Additional materials with hemostatic (hemostatic) properties can also be used.

In the artificial kidney apparatus, which is used today, convection is used along with diffusion. It is also carried out through the membrane due to the fact that there are different pressures in the patient's blood and in the dialysate solution. It is created by a special pump available in the device. Thanks to convection, it is possible to rid the blood of excess fluid. All processes are computer controlled.

Thus, using the modern Artificial Kidney device, effective blood detoxification is carried out from:

substances formed during the breakdown of proteins (urea);
energy metabolism products (creatinine);
various poisons, ranging from arsenic to mushroom toxins;
medical supplies;
alcohol (both ethyl and methyl);
electrolytes - sodium, potassium, calcium;
excess water.

Today it is no longer necessary to prove the effectiveness of hemodialysis. Millions of people pass it every day in the world. It significantly increases the patient's life expectancy and allows waiting for the appearance of a donor organ suitable for transplantation.

The list of indications for hemodialysis is quite extensive. But all these cases have one thing in common: the patient's condition must be critical, when there are simply no other ways to save his life.

The hemodialysis procedure is carried out in the following conditions:

loss of functionality by the kidneys (both in acute and chronic form);
poisoning with medicines and poisons;
severe alcohol poisoning (including methyl alcohol intoxication);
changes in the composition of electrolytes in the blood;
accumulation of a significant amount of water in the tissues, pulmonary edema.

If there is any disease from the above list, you can purify the blood in other ways. Specific indications for hemodialysis are determined based on the results of blood and urine tests.

The only way to save the patient is when there is a transcript of analyzes showing the following results:

with a significant decrease in the volume of urine produced per day (500 ml or less);
with a significant increase in the content of urea in the blood plasma (35 mmol / l and more);
if the patient's blood contains keratonin from 1 mmol / l and above;
potassium level is more than 6 mmol / l;
bicarbonate level - 20 mmol / l;
if the functionality of the kidney is no more than 10-15% (less than 200 ml of blood is filtered per minute).

In some cases, hemodialysis is also prescribed for diabetes mellitus, since it can be used to lower the sugar content and significantly improve the patient's condition.

In medicine, different types of hemodialysis are used. They can be classified according to different principles.

In this regard, the types of procedures differ in the following way:

at the place where it is held;
by the functionality of the "artificial kidney" device;
on the ultimate goal of the procedure.

Cleaning can be done in different places, it is done:

at home;
outpatient;
in the hospital.

Carrying out the procedure in different places has its own advantages and disadvantages. Hemodialysis at home is good in that the device for cleaning, which can be used at home, has a compact size, you can do hemodialysis on it for a period of 2 to 4 hours. Using a home machine, you can maximally coordinate the hemodialysis procedure with the needs of the body, there is no connection to a medical institution. But this type of hemodialysis has a very high cost. As much as such equipment costs, most of our citizens will not be able to pay. Therefore, this type of cleaning is not very popular in our country.

On an outpatient basis, the place where hemodialysis is performed is a special clinic. The patient needs to go through it three times a week. The cleaning time is 4 hours. Best of all, this method is suitable for those people who have acute renal failure, or failure in a chronic form, when it is no longer possible to restore the organ's previous working capacity.

When carrying out the procedure on an outpatient basis, the advantages include the fact that the patient is constantly available to specialists, continuous adjustment of treatment is carried out. In such centers it is possible to achieve the required level of sterility, which is very important during hemodialysis.

The disadvantage is that the patient is tied to a medical facility that needs to be visited frequently, the need to wait for his turn, and, albeit small, but the likelihood of contracting hepatitis.

In a hospital, hemodialysis is carried out for those patients who come with severe poisoning. The equipment for making it is available in all large clinics. The mechanism of the procedure is carried out in the same manner and does not differ from what is carried out on an outpatient basis. There are no differences in the equipment used. The advantage in this case is the constant monitoring of the patient by specialists, and the disadvantages include the need to constantly be in the hospital and a higher risk of hepatitis infection than under previous conditions.

According to the features of the functionality of the device, hemodialysis can be divided into the following types:

normal;
highly efficient;
using high permeability membranes.

The machine used for conventional hemodialysis uses a cellulose membrane with a size of 0.8 to 1.5 m². It can only pass small particles. The procedure takes 4-5 hours, and the blood flow rate is up to 300 ml per minute.

Highly effective hemodialysis uses a machine called a dialyzer. Through its membrane, movement is carried out in two directions: in one there is a blood flow at a speed of 350-500 ml per minute, and in the other, dialysate moves at a speed of up to 800 ml per minute. Thus, the membrane is used more efficiently and the procedure time is reduced to 3-4 hours.

By using membranes with high permeability, large molecules can be filtered during hemodialysis. This improves the quality of the procedure and reduces the likelihood of complications, but at the same time increases the risk of dialysate components entering the bloodstream. Therefore, when using this type of hemodialysis, sterility plays an important role.

By the nature of the patient's condition, two types of procedure can be distinguished:

acute hemodialysis;
chronic hemodialysis.

The use of acute hemodialysis is indicated in the presence of acute renal failure, which occurs against the background of severe intoxication of the body through various poisons, alcohol, drug overdose and other similar conditions. The purpose of manipulation in these cases is to restore normal kidney function. Acute hemodialysis may require only one treatment.

Chronic dialysis is used for chronic renal failure (CRF), when the restoration of normal kidney function is no longer possible.

It is aimed primarily at maintaining the vitality of the body and is carried out on an ongoing basis with a certain frequency. Therefore, there is such a definition as programmed hemodialysis, because it is possible to program hemodialysis for a long time.

It is impossible to learn all about hemodialysis without considering alternative methods of blood purification. Peritoneal dialysis is such an alternative.

The indications for it are the following situations:

The patient has contraindications to hemodialysis.
There is no opportunity to visit the hemodialysis center.
It is impossible to find a place on the patient's body to connect the artificial kidney apparatus.

To prepare the patient for peritoneal dialysis, a special hole is formed in his peritoneum through which the procedure will be carried out in the future. A catheter is inserted into the hole and 2 liters of dialysate is poured into the hole. After that, the catheter is closed and the person can go about their usual activities. In this case, the human abdominal cavity is used as a filter. The filtration process itself takes place through the capillaries located in the peritoneum. After 6 hours, the solution must be drained and filled with a new one. Thus, the procedure is carried out 4 times a day.

The advantages of this method include the fact that it does not require expensive equipment and can be carried out at home. The disadvantage is that it is impossible to 100% exclude the entry of pathogenic microbes into the peritoneum. Therefore, the risk of peritonitis is high.

There are also contraindications for this method. Peritoneal dialysis cannot be done if the patient has intestinal adhesions or is obese.

Hemodialysis is a very serious procedure. Each session is a test for the body and carries the risk of rather severe complications.

During hemodialysis, complications can be as follows:

Pressure surges. Most often they happen downward. The risk of this complication is especially high in elderly people with heart problems. This situation is associated with the fact that the intake of liquid for dialysis is carried out too quickly. Therefore, it is reduced. The opposite, when the pressure rises sharply, also happens. In this case, the rate of fluid intake is increased, and the patient can be given pressure pills.
Convulsions. They are also caused by excessive fluid intake. Therefore, if they occur, the procedure is stopped, and the patient is injected with hypertonic solutions.
Nausea turning into vomiting. This symptom is associated with a sharp drop in blood pressure.
Biocompatibility reaction. It develops when blood comes into contact with the components of the dialysate solution. The patient may develop signs of allergy up to anaphylactic shock, which can lead to serious consequences. In such cases, it is necessary to identify the component to which the reaction occurs and replace it with some kind of analogue.

The severity of the procedure and the complications of hemodialysis raise the question of how long one can live in such a situation. How long people live on kidney hemodialysis depends on several factors. The main role is played by the chosen treatment tactics. It is also important to ensure vascular access and adherence to the correct regimen of water consumption.

Statistics show that on average people live on hemodialysis for 10 to 15 years.

There are situations when a patient has all the indications for him to undergo a blood purification procedure, but he is not prescribed. Contraindications for hemodialysis have their own characteristics. They are divided into absolute and relative.

Absolute contraindications include:

cirrhosis of the liver;
pulmonary tuberculosis in active form;
conditions that can cause sudden severe bleeding.

Contraindications, which are of a relative nature, include:

mental illness;
advanced oncological diseases;
blood diseases;
problems with the nervous system;
pregnancy;
alcoholism or drug addiction;
Advanced age (more than 80 years old, and with diabetes mellitus - more than 70 years).

Speaking about contraindications to hemodialysis, it should be noted that in urgent cases, when the question is that people live on, despite the possible risks, the cleaning procedure is still carried out.