Hemodialysis is the most common method used to treat advanced and permanent kidney failure. Since the 1960s, when hemodialysis first became a practical treatment for kidney failure, much have been learnt about how to make hemodialysis treatments more effective and minimize side effects. In recent years, more compact and simpler dialysis machines have made home dialysis increasingly attractive. But even with better procedures and equipment, hemodialysis is still a complicated and inconvenient therapy that requires a coordinated effort from the whole health care team, including the nephrologist, dialysis nurse, dialysis technician, dietitian, and social worker. The most important members of the health care team are the patient and his/her family. By learning about the treatment, the patient can work with the health care team to give the best possible results, and the patient can lead a full, active life.

When The Kidneys Fail

Healthy kidneys clean a person's blood by removing excess fluid, minerals, and wastes. They also make hormones that keep bones strong and blood healthy. When the kidneys fail, harmful wastes build up in the body, the blood pressure may rise, and the body may retain excess fluid and not make enough red blood cells. When this happens, treatment is needed to replace the work of the failed kidneys.

How Hemodialysis Works

In hemodialysis, blood is allowed to flow, a few ounces at a time, through a special filter that removes wastes and extra fluids. The clean blood is then returned to the body. Removing the harmful wastes and extra salt and fluids helps control the blood pressure and keep the proper balance of chemicals like potassium and sodium in the body.

One of the biggest adjustments a patient must make when hemodialysis treatments start is following a strict schedule. Most patients go to a clinic-a dialysis center-three times a week for 3 to 5 or more hours each visit. For example, a patient may be on a Monday-Wednesday-Friday schedule or a Tuesday-Thursday-Saturday schedule. He/she may be asked to choose a morning, afternoon, or evening shift, depending on availability and capacity at the dialysis unit. The dialysis center will explain the options for scheduling regular treatments.

Researchers are exploring whether shorter daily sessions, or longer sessions performed overnight while the patient sleeps, are more effective in removing wastes. Newer dialysis machines make these alternatives more practical with home dialysis.

Hemodialysis.

Even in the best situations, adjusting to the effects of kidney failure and the time a patient spend on dialysis can be difficult. Aside from the "lost time,?the patient may have less energy. Changes need to be made in work or home life, giving up some activities and responsibilities. Keeping the same schedule kept when the kidneys were working can be very difficult now that the kidneys have failed. Accepting this new reality can be very hard on the patient and the family.

Many patients feel depressed when starting dialysis, or after several months of treatment. Such patients should talk with the social worker, nurse, or doctor because this is a common problem that can often be treated effectively.

Getting Your Vascular Access Ready

Arteriovenous fistula

Graft

One important step before starting hemodialysis is preparing a vascular access, a site on your body from which your blood is removed and returned. A vascular access should be prepared weeks or months before you start dialysis. It will allow easier and more efficient removal and replacement of your blood with fewer complications.

The dialysis machine is about the size of a dishwasher. This machine has three main jobs:

• pump blood and watch flow for safety
• clean wastes from blood
• watch the blood pressure and the rate of fluid removal from the body

Structure of a typical hollow fiber dialyzer

The dialyzer is a large canister containing thousands of small fibers through which blood is passed. Dialysis solution, the cleansing fluid, is pumped around these fibers. The fibers allow wastes and extra fluids to pass from the blood into the solution, which carries them away. The dialyzer is sometimes called an artificial kidney.

• Reuse. The dialysis center may use the same dialyzer more than once for treatments. Re-use is considered safe as long as the dialyzer is cleaned before each use. The dialyzer is tested each time to make sure it is still working, and it should never be used for anyone but the same patient. Before each session, it must be ascertained that the dialyzer is labeled with the patient's name and it has been cleaned, disinfected, and tested.

Dialysis solution, also known as dialysate, is the fluid in the dialyzer that helps remove wastes and extra fluid from the blood. It contains chemicals that make it act like a sponge. The doctor will give the patient a specific dialysis solution for the treatments. This formula can be adjusted based on how well the patient handle the treatments and on the blood tests.

Many people find the needle sticks to be one of the hardest parts of hemodialysis treatments. Most people, however, report getting used to them after a few sessions. If the needle insertion is painful, an anesthetic cream or spray can be applied to the skin. The cream or spray will numb the skin briefly so the needle won't be felt.
Most dialysis centers use two needles-one to carry blood to the dialyzer and one to return the cleaned blood to the body. Some specialized needles are designed with two openings for two-way flow of blood, but these needles are less efficient and require longer sessions. Needles for high-flux or high-efficiency dialysis need to be a little larger than those used with regular dialyzers.

Arterial and venous needles

Some people prefer to insert their own needles. Training is required on inserting needles properly to prevent infection and protect the vascular access. The patient may also learn a "ladder?strategy for needle placement in which the needle insertion point "climb?up the entire length of the access session by session so that no area is weakened with a grouping of needle sticks. A different approach is the "buttonhole?strategy in which a limited number of sites is used by inserting the needle back into the same hole made by the previous needle stick.

About once a month, the dialysis care team will test the patient's blood by using one of two formulas-URR or Kt/V-to see whether the treatments are removing enough wastes. Both tests look at one specific waste product, called blood urea nitrogen (BUN), as an indicator for the overall level of waste products in your system.

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