Dialysis is a treatment for severe kidney failure (also called renal failure, stage 5 chronic kidney disease, and end-stage renal disease). When the kidneys are no longer working effectively, waste products and fluid build up in the blood.

Dialysis take over a portion of the function of the failing kidneys to remove the fluid and waste. Dialysis is typically needed when about 90 percent or more of kidney function is lost. This usually takes many months or years after kidney disease is first discovered. Early in the course of kidney disease, other treatments are used to help preserve kidney function and delay the need for replacement therapy.

WHICH TYPE OF DIALYSIS IS BEST?

Once dialysis becomes necessary, you (along with your physicians) should consider the advantages and disadvantages of the two types of dialysis:

  • Hemodialysis (in-center or at home)
  • Peritoneal dialysis

The choice between hemodialysis and peritoneal dialysis is influenced by a number of issues such as availability, convenience, underlying medical problems, home situation, and age. This choice is best made by discussing the risks and benefits of each type of dialysis with a healthcare provider.

VASCULAR ACCESS

An access creates a way for blood to be removed from the body, circulate through the dialysis machine, and then return to the body at a rate that is higher than can be achieved through a normal vein. There are three major types of access: primary AV fistula, synthetic AV bridge graft, and central venous catheter. Other names for an access include a fistula or shunt.

The access should be created before hemodialysis begins because it needs time to heal before it can be used. Discussions about the access should begin even earlier, since you will need to avoid injuring blood vessels that will eventually be used for access. Having an intravenous line (IV) or frequent blood draws in the arm that will be used for access can damage the veins, which could prevent them from being used for a hemodialysis access. The access is usually created in the non-dominant arm; for a right-handed person this would be their left arm.

After the access is placed, it is important to monitor and care for it over time.

Primary AV fistula — A primary AV fistula is the preferred type of vascular access. It requires a surgical procedure that creates a direct connection between an artery and a vein. This is often done in the lower arm, but can be done in the upper arm as well. Sometimes a vein that would not normally be useful for creating an AV fistula can be moved so that it is more accessible; this is often done in the upper arm. Regardless of its location or how it is created, the access is located under the skin. During dialysis, two needles are inserted into the access. Blood flows out of the body through one needle, circulates through the dialysis machine, and flows back into the access through the other needle.

A primary AV fistula is usually created two to four months before it will be used for dialysis. During this time, the area can heal and fully develop or “mature”.

Synthetic bridge graft — Sometimes, a patient’s arm veins are not suitable for creating a fistula. In these cases, a surgeon can use a flexible rubber tube to create a path between an artery and vein. This is called a synthetic bridge graft. The graft sits under the skin and is used in much the same way as the fistula except that the needles used for hemodialysis are placed into the graft material rather than the patient’s own vein.

Grafts heal more quickly than fistulas and can often be used about two weeks after they are created. However, complications such as narrowing of the blood vessels and infection are more common with grafts than with AV fistulas.

Central venous catheter — A central venous catheter uses a thin flexible tube that is placed into a large vein (usually in the neck). It may be recommended if dialysis must be started immediately and the patient does not have a functioning AV fistula or graft. This type of access is usually used only on a temporary basis. In some cases, however, there can be problems maintaining an AV fistula or graft, and the central venous route is used for long-term access.

Catheters have the highest risk of infection and the poorest function compared to other access types; they should be used only if a primary fistula or synthetic bridge graft cannot be maintained.

DIETARY CHANGES

Some patients, especially those who receive dialysis in a center, will need to make changes in their diet before and during hemodialysis treatment. These changes ensure that you do not become overloaded with fluid and that you consume the right balance of protein, calories, vitamins, and minerals.

A diet that is low in sodium, potassium, and phosphorus may be recommended, and the amount of fluids (in drinks and foods) may be limited. A dietitian can help you to choose foods that are compatible with hemodialysis treatment.