Hemodialysis

Overview

In hemodialysis, also called dialysis, a machine sends your blood through a filter called a dialyzer. The filter removes wastes, salts and extra fluid before the blood returns to your body. Hemodialysis (he-moe-die-AL-uh-sis) is one way to treat advanced kidney disease. It can help manage fluid levels, blood pressure, and levels of minerals such as potassium and sodium when the kidneys cannot do this well enough.

With hemodialysis, you'll need to:

• Follow a regular treatment schedule.
• Take medicines regularly.
• Make changes in your diet.

You work closely with your healthcare team, including a kidney specialist and other professionals with experience managing hemodialysis. Hemodialysis can be done in a dialysis center, hospital or home, depending on your needs, training and treatment plan.

Why it's done

Your healthcare team may recommend hemodialysis if advanced kidney disease or a sudden kidney injury causes wastes, extra fluid or minerals to build up in your body. A blood test called estimated glomerular filtration rate (eGFR) helps show how well your kidneys are filtering your blood. A lower eGFR means your kidneys are filtering less well.

The decision to start hemodialysis is not based on eGFR alone. It also depends on your symptoms, overall health, quality of life and treatment goals.

Hemodialysis may be needed if you have very low eGFR along with symptoms such as nausea, vomiting, loss of appetite, weight loss, severe itching, tiredness or confusion. It also may be needed if you have kidney failure that is causing too much fluid in your body, high potassium levels or too much acid in your blood. In some situations, hemodialysis also can remove certain toxins or medicines from the blood.

Some people with advanced chronic kidney disease may be able to have a kidney transplant and not need to start dialysis. Others with kidney failure may choose care that focuses on managing symptoms and quality of life without dialysis. Your care team can help you understand dialysis, transplant and other care options based on your health needs and goals.

Risks

Many people who need hemodialysis also have other health conditions. And hemodialysis does not do everything that healthy kidneys do. Your dialysis team watches you closely because symptoms and complications can happen during treatment, between treatments or after years of treatment.

You can help lower your chances of complications during and after dialysis by following your care plan. Limit fluids and salt as directed, and take your medicines as prescribed.

During or soon after hemodialysis

During dialysis treatment, you may have some of these conditions, but you likely won't experience all of these issues:

• Low blood pressure. A drop in blood pressure is common during hemodialysis. It may cause dizziness, lightheadedness and cramping. It also may cause nausea, vomiting, shortness of breath or changes in alertness.
• Muscle cramps. Cramps may happen when a large amount of fluid is removed during treatment. Changes in blood pressure or levels of minerals such as potassium, calcium or magnesium also may play a role.
• Nausea, vomiting and headache. These symptoms may be related to low blood pressure, changes in fluid or mineral levels, a reaction to the dialyzer, or dialysis that is not removing enough waste.
• Chest pain or shortness of breath. These symptoms may have many causes, including low blood pressure, heart disease, heart rhythm changes, inflammation around the heart or, rarely, air entering the bloodstream.
• Bleeding. Blood-thinning medicine often is used during hemodialysis to keep blood from clotting in the dialysis machine. Because of this, bleeding can happen from the access site after needles are removed.

Between treatments and over time

Possible risks from ongoing dialysis include:

• Infection. A fistula, graft or catheter where blood moves between your body and the dialysis machine can become infected. A bloodstream infection can cause fever, chills, low blood pressure or serious illness.
• Narrowing, clotting or swelling of the access site. A fistula, graft or catheter used for dialysis access can narrow, clot or develop other issues that make hemodialysis less effective.
• Too much fluid. Drinking more fluid than recommended and eating salty food between treatments can lead to swelling, high blood pressure, shortness of breath or heart failure.
• Mineral changes. Potassium, calcium and phosphorus levels can become too high or too low. These changes may affect the heart, bones, muscles or nerves.
• Anemia. Not having enough red blood cells in your blood is called anemia. Kidney failure can lower the body’s supply of a hormone that helps make red blood cells. Blood loss from testing or dialysis also can contribute to anemia.
• Bone and mineral disease. Kidney failure can affect vitamin D, calcium, phosphorus and parathyroid hormone levels. These changes can weaken bones over time.
• Itching. Itching is common in people receiving hemodialysis. It may be related to waste buildup, dry skin, phosphorus imbalance, or bone and mineral disease.
• Sleep or mood changes. Some people receiving hemodialysis have trouble sleeping, restless legs, anxiety or depression. Tell your care team if these symptoms affect your daily life. 
• Amyloidosis. After years of hemodialysis, proteins can build up around joints and tendons. This is called dialysis-related amyloidosis. This can cause pain, stiffness, fluid in the joints or carpal tunnel syndrome.

Your dialysis team can help you manage any complications from dialysis.

Tell your dialysis team right away if you have chest pain, shortness of breath, fainting, fever or chills. Tell them if you have sudden weakness, confusion, bleeding that does not stop, severe pain or changes in your access site. These changes may include swelling, drainage, a new lump or loss of pulse. They also may include loss of the buzzing or vibrating feeling over the access site. This feeling is called a thrill.

How you prepare

Preparation for hemodialysis often starts weeks to months before treatment begins. Before treatment can start, your healthcare team needs to set up a safe way for blood to move between your body and the dialysis machine. This pathway is called vascular access or dialysis access. During dialysis treatment, blood leaves your body through the access, passes through the dialyzer to be filtered, and returns to your body through the access.

Your care team may talk with you about how to protect arm veins before access is created. This may include avoiding any unneeded blood draws, IV lines or peripherally inserted central catheters in an arm that may be used for dialysis access. Before access surgery, your care team may check blood vessels with a physical exam and ultrasound or other vein mapping tests.

Types of dialysis access include:

• Arteriovenous fistula. An arteriovenous fistula, also called an AV fistula, is a surgical connection between an artery and a vein, usually in the arm. It typically is preferred for long-term hemodialysis because it tends to last longer and has lower risks of clotting and infection than other access types.
• Arteriovenous graft. An arteriovenous graft, also called an AV graft, uses a synthetic tube to connect an artery and a vein. A graft may be used when blood vessels are not suitable for an arteriovenous fistula.
• Central venous catheter. A central venous catheter is a tube placed into a large vein, often in the neck or chest. A catheter may be used for emergency or short-term hemodialysis, while a fistula or graft matures, or when other access options are not possible.

Follow your care team's instructions for caring for your access site and checking it before each treatment. Ask what changes to report and who to contact after hours.

You may meet with your dialysis team to plan your care. This team may include a kidney specialist, dialysis nurse, dietitian, social worker or technician. They can help you review your treatment schedule, medicines, diet, fluid limits, transportation and, when needed, home hemodialysis training.

What you can expect

Hemodialysis can take place in a dialysis center, at home or in a hospital.

In-center hemodialysis often is done three times a week. Each treatment usually takes about 3 to 5 hours, but your schedule depends on your health needs.

You may be able to travel while receiving hemodialysis. Dialysis centers are available in many places. Your dialysis team can help you plan treatments while traveling. Your team can schedule treatments at another center, or you can contact the center directly. Plan ahead so the center has space and the information needed for your care.

Home hemodialysis may involve shorter treatments done more often, or longer treatments done overnight. Before starting home hemodialysis, you and anyone who helps you will need training and a care plan from your dialysis team.

During hemodialysis

At the start of treatment, your care team checks information such as weight, blood pressure, pulse and temperature. The skin over the access site is cleaned before needles are placed in a fistula or graft or before a catheter is connected to the dialysis tubing.

During treatment, blood travels through tubing to the dialyzer. A cleansing fluid called dialysate flows on the other side of a thin membrane in the dialyzer. Wastes and extra fluid move from the blood into the dialysate. The cleaned blood then returns to your body.

Your blood pressure and symptoms are checked during treatment because blood pressure and fluid levels can change while fluid is removed. Tell your healthcare team if you feel dizzy or if you feel like throwing up. Tell them if you are short of breath, itchy, anxious, chilled, hot or uncomfortable. Also tell your care team if you have cramps or chest pain.

You may be able to read, watch a show, rest or sleep during treatment, depending on where and when you receive hemodialysis. If you do home hemodialysis, you and a trained helper, if needed, will follow a care plan from your dialysis team.

After hemodialysis

When treatment is finished, the needles or catheter lines are disconnected, and pressure is applied to help stop bleeding at the access site. Your weight and blood pressure may be checked again. These measurements help your care team understand how much fluid was removed and how you tolerated treatment.

Many people return to usual activities after in-center dialysis, but tiredness, low blood pressure, cramping, nausea or headache can happen after treatment. Your care team may adjust your dialysis prescription, medicines, fluid goals or dialysate if symptoms keep happening.

Results

The goal of hemodialysis is to remove enough waste and extra fluid from your blood to help you feel better and lower the risk of complications from kidney failure.

Your care team checks how well hemodialysis is working. You may have blood tests before and after treatment to measure urea, a waste product in the blood. These tests include the urea reduction ratio (URR) and Kt/V. Both tests help show whether dialysis is removing enough waste.

Your care team also may check your:

• Blood pressure and weight before, during and after treatment.
• Blood counts and blood chemistry.
• Potassium, calcium, phosphorus and albumin levels.
• Blood flow through your access site.

Your care team may change how long, how often or how intensely you receive hemodialysis based on your symptoms, test results, fluid levels, remaining kidney function and treatment goals.

If you are receiving hemodialysis for a sudden kidney injury, you may need treatment only for a short time if your kidneys recover. If you had long-term kidney disease before the sudden injury, full recovery is less likely.

If you have advanced chronic kidney disease, hemodialysis usually continues unless you receive a kidney transplant, change to another type of dialysis or choose another care plan.

Between treatments, you can help hemodialysis work well by following your care plan for food, fluids and medicines. Your plan may include limits on sodium, potassium, phosphorus or fluids. A dietitian can help you choose foods that fit your health needs and preferences.

Talk with your care team if symptoms, travel plans, home responsibilities, transportation, cost or mood changes make your treatment plan hard to follow. Your team may be able to help.

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