Hemodialysis-patient information

As patients, their families and carers need to know?

Hemodialysis (HD) is the most common form of treatment of patients with terminal renal failure. If you start treatment with hemodialysis, it means that you there is still only 10-15% of normal kidney function. It is not enough to cleanse the body of toxins and keep healthy. At that time you have symptoms such as anemia, nausea, vomiting, fatigue and sweating (especially the palms, feet and ankles).

It is important to know that hemodialysis is not a cure for your sick kidneys. By the time you be healthy transplanted kidney, you will need to be treated with some form of dialysis, sometimes for life.Some patients have lived 35 more years on hemodialysis. They can tell you how important it is to stick to strict schedules of dialysis, medications are prescribed and the child to have a long and productive life as a terminal kidney patient.

How is hemodialysis?

Nearly 90% of patients in terminal renal dialysis centers in 3-5 hours of dialysis three times a week. In most centers this is done on schedule Monday-Wednesday-Friday or Tuesday-Thursday-Saturday, and the time is morning, afternoon or evening. During hemodialysis using a special machine and the filter used for blood purification of patients. This is done by surgically constructed to access the bloodstream, usually on hand, as described earlier.

Dialysis membrane filter is divided into two parts. The first is the blood of patients that leads from the body and cleanses the toxins, and then back into the body. The second is called the dialysate fluids used for Ťispiranjeť. Sewage purposes of substances from the blood such as urea, potassium, creatinine and excess fluid pass through the dialysis membrane and is removed by the dialysate.

The adequacy of hemodialysis

In the initial implementation of chronic hemodialysis (60's and early 70-ies of the 20th century), nephrologists did not know how dialysis takes to keep patients healthy. Once you have learned how to maintain blood values ​​essential substances, eg. potassium, optimal, put the problem in order to maintain long-term patients and healthy living. Patients suffering from complications such as infection and inflammation.

It was found that many of these complications can be reduced or even removed a longer time interval of the dialysis (8-12 hours), and patients to accept in the hope that makes them relatively healthier. Nephrologists have noticed that their patients will not accept a longer time interval of dialysis and began to explore the value or Ťmarkereť that will help them to more accurately determine the amount received adequate dialysis therapy.

"Markers" adequacy of dialysis

Following some of the "markers", doctors have found a more precise way odeđivanja adequacy of dialysis therapy.

- Urea or blood urea nitrogen levels in the blood: Urea is a waste product of protein that we take food to digest and break down and which are normally excreted in urine. Nephrologists found that patients in worse condition that it is the level of urea in the blood higher. Urea is a small molecule that is removed through the dialysis membrane. In dialysis scheme Monday-Wednesday-Friday, the level of urea in the blood is highest on Monday before dialysis, and the lowest on Friday after the last weekly dialysis.

- Kt / V: Two well-known nephrologists have discovered a simple formula for the measurement of dialysis therapy. "K" is the "clearance" of urea in milliliters per minute. TTT has Ťvrijemeť in minutes, a "V" the volume of body water in liters. Since the formula used by the individual volume of each patient's body fluids, resorted to the "standardization", because patients who are equally heavy volume can have different body fluids. Experts have recommended the value of Kt / V of 1.2 or more as optimal for adequate diajlize.

- Urea kinetic model: using the value of Kt / V for the definition and measurement of dialysis therapy.This "marker" is used the level of urea in the blood before and after dialysis, analyzes of protein metabolism and protein shows that the patient currently has in their diet. At first the doctors thought it was better if the patient takes less protein in their diet. Further experiments showed that it is better that the patient consume more, not less protein. Anyway, today is the attitude of medicine such that the part of patients with residual renal function advises restricted protein intake to maintain the healthy function. It is very important that you consult with your nephrologist about the amount of protein in the diet that is most appropriate for you.

- The ratio of urea elimination: elimination of urea, the end result of dialysis, is a measure used to determine the efficiency of elimination Waste products of metabolism from the body. This "marker" is expressed as a percentage. Significant world health authorities recommend 65% or more and is usually measured once a month. The ratio of urea elimination of 65% is equivalent to the value of Kt / V of 1.2.The ratio of urea elimination of 65% and the value of Kt / V of 1.2 as the optimum value of dialysis adequacy. Numerous studies have shown that patients with a permanently lower Kt / V or lower ratio of urea elimination have more health problems and increased risk of death.

Home hemodialysis

Several years ago, more and more patients and nephrologists has documented the benefits of implementation of dialysis at home, because if there are opportunities. Several hundred scientific papers published on the subject in the last three decades. Patients can learn to perform hemodialysis three times a week at your own home. Some patients practice daily or nocturnal hemodialysis (6-7 times per week). The data suggest that patients who are dialysis longer time interval several times a week at home, live longer than those who do it three times a week at dialysis centers.

Hemodialysis - dialyzer

Hemodialysis is done so that blood flows out of a special tube and purified, and then distilled back into the body of another tube.

In the process of dialysis are important parts:

dialyzer

device for hemodialysis

Solution for hemodialysis

equipment (needles, tubes)

The most important part of the dialyzer or artificial kidney, which contains a semi-permeable membrane to form capillaries. Through this membrane pass only molecules of certain sizes and water.

Dialyzer is attached to a dialysis machine and changing with each dialysis.

The dialysis solution or dialysate is an electrolyte solution similar to plasma without proteins. The solution maintains the electrolyte balance and participates in the process of purifying the blood.

The device is a dialysis machine that contains the prepared dialysate pump, and pump blood and to maintain a constant temperature of blood and dialysate to their steady flow.

Most patients have dialyis to 3 times a week and the process takes approximately 4 hours.

Vascular access

Patients undergoing hemodialysis should have access to the path of blood in the form of hemodialysis arteriovenous fistula, graft or catheter. When creating a small fistula surgeon procedure under the skin, usually on the wrist connects the artery and vein. If blood vessels are too weak to make a fistula is formed graft (graft blood vessels), and catheters are typically used temporarily, but may be permanent.

When you establish an adequate approach to the patient with two outputs are connected to the device for hemodialysis. Questions are two pins, soft tubes connected part that comes from the arteries leading into the camera, and the part that comes out of the device leads to a vein.

HISTORY OF DIALYSIS

First century. pr. BC: In China records first mentioned organ transplantation under general anesthesia.

13th st: Giugliermo Saliceto in Durities in Renibus: "The pressure in the kidneys ... or can not be treated successfully, or can not be cured."

17th century. William Shakespeare: Henry IV.

Falstaff: "What does the doctor about my water?"

Page: "He says, sir, that water is in itself a good, healthy water, but its owner would have to have a disease which is not conscious."

1861st Thomas Graham introduced the concept of the physical chemistry of making use of selectively permeable dialysis membrane to separate big molecular substances and low molecular substances from solution.

1922nd It was discovered in heparin, but it began as a systemic anticoagulant prescribed only twenty years later. Until then prescribed hirudin, an anticoagulant, which is very uncertain is received from the heads of leeches.

HEMODIALYSIS

1924th Haas George spent the first successful hemodialysis in patients with end-stage renal failure.Dialysis lasted 15 minutes and went without complications.

1944th Willem Kolff in the Netherlands, then under Nazi occupation, constructed the first device for hemodialysis. As a dialysis membrane was used cellophane. Kolff was after the war emigrated to the United States has developed several other hemodialysis machines that were used in the Korean War.

1946th Nils Alwall produced the first hemodialysis machine with controlled ultrafiltration.

1960th Belding Scribner made the first permanent vascular access, thus creating the foundation for the development of chronic hemodialysis. Fistula is composed of two tubes embedded in the blood vessels, which were then merged together with a piece of Teflon placed on a steel plate. A few years later created a simpler version of such a vascular access, so called. "Shunt poor." It consisted of two tubes embedded in the artery and vein and connected teflon loop.

1962nd In Seattle, he began to work the first center for chronic hemodialysis. The first patients were Clyde Shields (died in 1971. In) and Harvey Gentry (died in 1987. In).

1966th Cimino and Brescia were first described subcutaneous arterio-venous fistula, obtained by connecting the radial artery and vein. Such a form of cardiovascular approach used today in patients on chronic hemodialysis.

R. The Hickman and B. H Scribner become effective hemodialysis in children.

Haemofiltration

1966th In the U.S. and Germany conducted the first tests of new membranes for dialysis, propusnijih for midsize molecules.

1977th Kramer is, when setting up a system for haemofiltration, mistakenly punktirao femoral artery instead of vein. Artery blood pressure was sufficient to maintain the extracorporeal blood flow. In this way the first time carried out continuous arterio-venous hemofiltration (CAVH).

1982nd Bischoff puncturing the femoral vein and the addition of blood pumps in vitro bloodstream achieve greater and greater blood flow ultrafiltration. This resulted in continuous veno-venous hemofiltration (CVVH).