Chronic kidney disease and
acute kidney injury (also known as acute renal failure) cause the kidneys to lose their
ability to filter and remove waste and extra fluid from the body.
Hemodialysis is a process that uses a man-made
membrane (dialyzer) to:
- Remove wastes, such as
urea, from the blood.
- Restore the proper balance of
electrolytes in the blood.
- Eliminate extra
fluid from the body.
For hemodialysis, you are connected to a filter (dialyzer)
by tubes attached to your blood vessels. Your blood is slowly pumped from your
body into the dialyzer, where waste products and extra fluid are removed. The
filtered blood is then pumped back into your body.
different types of hemodialysis. Talk about these with your doctor to decide
which one might be best for you.
- In-center hemodialysis. You go to a hospital
or a dialysis center. Hemodialysis usually is done 3 days a week and takes 3 to
5 hours a day.
- Home hemodialysis.
After you are trained, you do your dialysis treatments at home. Hemodialysis is usually done 3 days a week (or every other
day). Discuss with your doctor how long each session needs to be. A session
could be as long as 6 hours, which may help you feel better.
- Daily home
hemodialysis. After you are trained, you do your dialysis treatments at home.
Hemodialysis is done 5 to 7 days a week. Each session takes about 3 hours.
- Nocturnal home hemodialysis. After you are trained, you do your dialysis treatments at home. Hemodialysis is done 3 to 7 nights a week. Each session is done
overnight (about 6 to 8 hours).
Before treatments can begin, your doctor will need to
create a site where the blood can flow in and out of your body during the
dialysis sessions. This is called the
dialysis access. The type of dialysis access you have
will depend in part on how quickly you need to begin hemodialysis.
There are different types of access for hemodialysis:
Fistula. A fistula is created by connecting one of the
arteries to one of the veins in your lower arm. A fistula allows repeated
access for each dialysis session. It may take several months for the
fistula to form. A fistula may not clot as easily as other dialysis access
methods. A fistula is the most effective dialysis access and the most durable.
Complications include infection at the site of access and clot formation
Graft. A vascular access that
uses a synthetic tube implanted under the skin in your arm (graft) may be used
if you have very small veins. The tube becomes an artificial vein that can be
used repeatedly for needle placement and blood access during hemodialysis. A
graft does not need to develop as a fistula does, so a graft can sometimes be
used as soon as 1 week after placement. Compared with fistulas, grafts tend to
have more problems with clotting or infection and need to be replaced sooner. A
polytetrafluoroethylene (PTFE or Gore-Tex) graft is the most common type used
Venous catheter. A tube, or catheter, may
be used temporarily if you have not had time to get a permanent access. The
catheter is usually placed in a vein in the neck, chest, or groin. Because it
can clog and become infected, this type of catheter is not routinely used for
permanent access. But if you need to start hemodialysis right away, a catheter
may be used until your permanent access is ready.
Hemodialysis for acute kidney injury may be done daily
until kidney function returns.
What To Expect After Treatment
About once a month, you will have blood tests to make
sure you are getting the right amount of hemodialysis. These tests are done to
help find out how well hemodialysis is working. Your weight before and after
each session will be recorded, as will the length of time it takes to complete
the dialysis session. If you have hemodialysis at home, you will need to keep
records of your weight before and after each session and the length of each
Why It Is Done
Hemodialysis is often started after
symptoms or complications of
kidney failure develop. Symptoms or complications may
- Signs of
uremic syndrome, such as nausea, vomiting, loss of
appetite, and fatigue.
- High levels of
potassium in the blood
- Signs of the kidneys' inability to rid the body of
daily excess fluid intake, such as swelling.
- High levels of acid in
the blood (acidosis).
- Inflammation of the sac that surrounds the
Hemodialysis is sometimes used when acute kidney injury develops. Dialysis is always used with extra caution in people who have
acute kidney injury, because dialysis can sometimes cause low blood pressure,
irregular heart rhythms (arrhythmias), and other problems that can make acute
kidney injury worse.
How Well It Works
Hemodialysis may improve your
quality of life and increase your life expectancy. But hemodialysis provides
only about 10% of normal kidney function. It does not reverse chronic kidney
Dialysis has not been
shown to reverse or shorten the course of acute kidney injury. But it may be
used when fluid and electrolyte problems are causing severe symptoms or other
problems. Some people who develop acute kidney injury stay dependent on
hemodialysis and will go on to develop kidney failure.
Most complications that occur during dialysis
can be prevented or easily managed if you are monitored carefully during each
dialysis session. Possible complications may include:
- Low blood pressure (hypotension). This is the
most common complication of hemodialysis.
- Muscle cramps. If cramps occur, they usually
happen in the last half of a dialysis session.
- Irregular heartbeat
- Nausea, vomiting, headache, or confusion (dialysis
- Infection, especially if a central venous access
catheter is used for hemodialysis.
- Blood clot (thrombus) formation
in the venous access catheter.
- Technical complications, such as
trapped air (embolus) in the dialysis tube.
Long-term complications of dialysis may include:
- Inadequate filtering of waste products
- Blood clot (thrombus) formation in the
dialysis graft or fistula.
- Cardiovascular disease (heart disease, blood vessel disease, or
What To Think About
Choosing between treatment with
hemodialysis or peritoneal dialysis is based on your
lifestyle, other medical conditions, and body size and shape. Talk to your
doctor about which type would be best for you.
If you have severe
chronic kidney disease and you have not yet developed kidney failure, talk with
your doctor about which type of dialysis might work best for you.
People who have widely fluctuating blood pressure when they receive
hemodialysis (hemodynamic instability) may not be able to continue with
treatment. They may be switched to
Many people first
receive dialysis while waiting for a kidney transplant. Some people may have to
receive dialysis again if the kidney transplant fails.
Complete the special treatment information form (PDF)(What is a PDF document?) to help you understand this treatment.
Primary Medical Reviewer
||Anne C. Poinier, MD - Internal Medicine
Specialist Medical Reviewer
||Tushar J. Vachharajani, MD, FASN, FACP - Nephrology
Current as of
||August 29, 2013