What Is Hemodialysis?

Hemodialysis is a medical treatment that uses a machine with a special filter to take waste and extra water out of the blood. It can take over this job when the kidneys can't do it.

Why Do People Need Hemodialysis?

The main job of the kidneys is to clean the blood. They take out extra water and waste (things the body doesn't need). These leave the body as pee (urine).

If the kidneys don't work as they should, waste quickly builds up in the body and makes a person sick. When the kidneys stop removing enough waste and extra water from the blood, the person has kidney failure. Then, the person needs dialysis to clean the blood because the kidneys can't.

There are two types of dialysis: hemodialysis (hee-moh-dye-AL-ih-sis) and peritoneal dialysis (pair-eh-tih-NEEL dye-AL-ih-sis).

How Does Hemodialysis Work?

During hemodialysis, a machine removes blood from the bloodstream, cleans it, and returns it to the bloodstream. Only a safe amount of blood leaves the body at one time.

Before they get hemodialysis, children need a soft, flexible tube (a catheter) placed into a large vein, usually in the chest. This tube is a temporary pathway to get blood out of the bloodstream and back in again.

The catheter stays in place until doctors do another procedure to make a more permanent pathway. This permanent pathway is stronger than normal blood vessels and can handle the faster blood flow and repeated needle sticks needed for hemodialysis.

Doctors have two options for the pathway, which both happen in an arm. They can make:

  • a fistula (FISS-chuh-luh) by joining an artery to a nearby vein under the skin to make a bigger blood vessel
    or
  • a graft by using a flexible tube to join the artery to the vein

What Happens During Hemodialysis?

Hemodialysis usually takes place in a special clinic called a dialysis center. Some kids get treatments at a hospital.

A nurse connects the catheter, fistula, or graft to a needle and tubing that takes blood from the bloodstream. The blood goes into a special filter called a dialyzer (DYE-uh-lye-zer) or "artificial kidney."

The dialyzer has two parts: one for blood and one for a cleaning fluid called dialysate (dye-AL-uh-zate). A thin wall called a membrane separates these two parts. The membrane keeps important things inside the blood, like blood cells and proteins, which are too large to pass through it. Small waste and extra water pass through the membrane and are washed away. When the blood is clean, the machine sends it back to the child through another tube.

How Long Does Hemodialysis Take?

Most kids get dialysis three times a week. It takes about 4 hours each time.

During treatment, kids can lie down or sit in a chair. They can read, watch TV, play video games, or nap.

Is Hemodialysis Uncomfortable?

Each time a child has a hemodialysis treatment, a needle goes into the fistula or graft. After repeated treatments, most kids get used to the feeling. After treatment, kids sometimes feel tired. Some may have muscle cramps, headaches, nausea, or dizziness, but this is rare.

Are There Any Risks to Hemodialysis?

Hemodialysis does have some risks, including:

  • Problems with the catheter, fistula, or graft. Germs can get into the catheter, fistula, or graft and cause an infection. Blood clots can block the catheter, fistula, or graft. The treatment team will teach you how to recognize these problems so they can be handled right away.
  • Low blood pressure. Rarely, a person's blood pressure can go down during treatment. If this happens, they might be dizzy, have a headache, or feel sick (or throw up). The medical team can change the treatment plan to avoid this.
  • Itching. Hemodialysis can make the skin feel itchy, especially during or right after a treatment.
  • Sleep problems. Some people can have trouble sleeping due to aching or restless legs or brief pauses in breathing.

How Can Parents Help?

When kids need dialysis, staying healthy helps them avoid problems and feel their best. Here are a few tips:

  • Help kids eat the right foods. Kids on dialysis need to get the right amount — not too much or too little — of fluids, salt, vitamins, and minerals each day. Too much potassium or phosphorus, for example, can affect the heartbeat or weaken bones. A doctor or a dietitian at the dialysis clinic can give advice on the right meal plan.
  • Help kids remember to take medicine if needed. Kids often need medicines to control their blood pressure, help produce red blood cells, and control nutrient levels in the blood. Follow the doctor's instructions, and ask before your child takes any nonprescription medicines, vitamins, or other supplements.
  • Plan ahead. Make sure your child can continue treatments during travel. If you go to a dialysis clinic in a different town, call ahead and make sure they can fit your child into their schedule.

What Else Should I Know?

Kids and teens who get hemodialysis can go to school or work. They can still do most of their usual activities, planned around the dialysis schedule. Jobs and sports with lots of heavy lifting or contact, though, may not be OK to do. But even with some limits, kids still can do many things they enjoy.

Some people need dialysis treatments for the rest of their lives. If so, they might switch back and forth between hemodialysis and peritoneal dialysis, which usually can be done at home.

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