What Is Dialysis?

 

Dialysis is a procedure that is performed routinely on persons who suffer from acute or chronic renal failure or who have ESRD. The process involves removing waste substances and fluid from the blood that are normally eliminated by the kidneys. Dialysis may also be used for individuals who have been exposed to or ingested toxic substances to prevent renal failure from occurring. There are two types of dialysis that may be performed, including the following:

Peritoneal dialysis

Peritoneal dialysis is performed by surgically placing a special, soft, hollow tube into the lower abdomen near the navel. After the tube is placed, a special solution called dialysate is instilled into the peritoneal cavity. The peritoneal cavity is the space in the abdomen that houses the organs. It is lined by two special membrane layers called the peritoneum. The dialysate is left in the abdomen for a designated period of time, which will be determined by your physician. The dialysate fluid absorbs the waste products and toxins through the peritoneum. The fluid is then drained from the abdomen, measured, and discarded. There are three different types of peritoneal dialysis: continuous ambulatory peritoneal dialysis (CAPD), continuous cyclic peritoneal dialysis (CCPD), and intermittent peritoneal dialysis (IPD).

CAPD does not require a machine. Exchanges, often referred to as "passes," can be done three to five times a day during waking hours. CCPD requires the use of a special dialysis machine that can be used in the home. This type of dialysis is done automatically, even while you are asleep. IPD uses the same type of machine as CCPD, but treatments take longer. IPD can be done at home, but usually is done in the hospital.

Possible complications of peritoneal dialysis include an infection of the peritoneum, or peritonitis, where the catheter enters the body. Peritonitis causes fever and stomach pain. Your diet for peritoneal dialysis will be planned with a dietitian, who can help you choose meals according to your physician's orders. Generally:

  • You may have different protein, salt, and fluid needs
  • You may have different potassium restrictions
  • You may need to reduce your calorie intake since the sugar in the dialysate may cause weight gain

Hemodialysis

Hemodialysis can be performed at home or in a dialysis center or hospital by trained healthcare professionals. A special type of access called an arteriovenous (AV) fistula is placed surgically, usually in your arm. This involves joining an artery and a vein together. An external, central, intravenous (IV) catheter may also be inserted, but is less common for long-term dialysis. After access has been established, you will be connected to a large hemodialysis machine. The machine drains the blood; bathes it in a special dialysate solution, which removes waste substances and fluid; and then returns it to your bloodstream.

Hemodialysis is usually performed several times a week and lasts for 4 to 5 hours. Because of the length of time hemodialysis takes, it may be helpful to bring reading material to pass the time. During treatment you can read, write, sleep, talk, or watch TV.

At home, hemodialysis is done with the help of a partner, often a family member or friend. If you choose to do home hemodialysis, you and your partner will receive special training.

Possible complications of hemodialysis include muscle cramps and hypotension (sudden drop in blood pressure). Hypotension may cause you to feel dizzy, weak, or sick to your stomach. Side effects are prevented by following the proper diet and taking medications as prescribed by your physician. A dietitian will work with you to plan your meals according to your physician's orders. Generally:

  • You may eat foods high in protein, such as meat and chicken (animal proteins)
  • You may have different potassium restrictions
  • You may need to limit the amount you drink
  • You may need to avoid salt
  • You may need to limit food containing mineral phosphorus (such as milk, cheese, nuts, dried beans, and soft drinks)

Long-Term Outlook for End Stage Renal Disease

People with ESRD are living longer than ever. Dialysis treatments (both hemodialysis and peritoneal dialysis), however, are not cures for ESRD, but they will help you feel better and live longer. Over the years, ESRD can cause other problems, such as bone disease, high blood pressure, nerve damage, and anemia (having too few red blood cells). You should discuss prevention methods and treatment options for these potential problems with your physician.

Latest Renal Failure News
Chicken legs may control high blood pressure: study

October 9, 2008 — HONG KONG (Reuters) - Scientists in Japan have identified four proteins in chicken legs which appear to be effective in controlling high blood pressure, a study has said.

Blood pressure control poor with kidney disease

September 19, 2008 — NEW YORK (Reuters Health) - New research indicates that despite being informed about high blood pressure and its treatment, few patients with kidney disease are able to control their blood pressure.

Kidneys with small tumors okay for transplantation

August 22, 2008 — NEW YORK (Reuters Health) - The availability of kidneys for transplantation could be increased by using kidneys removed for small, incidentally detected tumors, the results of an Australian study suggest.

Select news items provided by Reuters Health