Haemodialysis
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Haemodialysis is an effective dialysis treatment for removing excess water and
waste products from the body. However, it is rarely the first choice of treatment in
young babies with kidney failure, as it is technically much more difficult than other
types of dialysis. Haemodialysis can become a necessary treatment for children
with kidney failure – when the kidneys stop working properly. Using a special
machine with an ‘artificial kidney’, haemodialysis removes extra water and waste
products from the blood. This partly replaces the work of healthy kidneys.
Haemodialysis usually takes place three or more times a week at your child’s
paediatric nephrology unit – a specialised unit at the hospital that treats babies,
children and young people with kidney conditions. The hospital can usually
arrange transport so your child can travel to and from the hospital. Some families
are able to do haemodialysis at home – and get equipment and training from the
hospital.
A team of healthcare professionals will do regular assessments – the amount of
time on dialysis and some other details will be adjusted especially for your child’s
needs. They will show you how to help manage your child’s health while on dialysis, and will look out for any
possible complications.
Haemodialysis is often shortened to HD. Another type of ‘haemodialysis’ performed in the hospital is
‘haemodiafiltration’, shortened to HDF. Another type of dialysis is peritoneal dialysis.
ÎÎFor a detailed overview of dialysis, and an introduction of both types, please read the topic Dialysis.
Overview
Preparing for haemodialysis
The haemodialysis machine will need to pump blood out
of and back into your child’s body. Your child will need a
procedure to allow access to the bloodstream. There are
two main options – creating a fistula and inserting a ‘line’.
Fistula
An arteriovenous fistula (usually shortened to fistula)
can be created. This joins two types of blood vessels to
make one large, stronger blood vessel – usually at the
wrist or elbow.
For regular dialysis sessions, the needle(s) are inserted
into the fistula. A fistula needs to be made about 8 weeks
Haemodialysis | Page 1
before dialysis starts, to allow time for it to develop and get
strong enough.
For many children who are on dialysis long term, a
fistula is the best option because there is much less risk
of infection or blockage. Occasionally, a fistula fails to
develop, or there is bleeding or other complications, and
some children need to come back for a new procedure.
With a good functioning fistula there is a ‘buzzing’ feeling
in the area around the fistula, and your child will be shown
how to take care of it.
»»Read more about creating and look after
a fistula in the infoKID topic Heamodialysis
fistula
Central venous line
Risks
A central venous line is a soft, long, thin tube (catheter)
that is placed into one of the large blood vessels in
your child’s body. This is usually in the neck or chest, or
occasionally the groin. It is often called a ‘line’.
Haemodialysis is a crucial, life-saving treatment for
children in kidney failure. It removes toxins and excess
water from their body which, if left untreated could reach
dangerous levels and become life threatening. The vast
majority of children with kidney failure are able to have this
treatment. However it has side-effects, has an impact on
your child’s and family’s lifestyle and carries risks.
A temporary line can be placed for children who will need
haemodialysis quickly or for a short time. For long-term
use, a permanent line is placed by surgery. For each
dialysis session, tubes are connected to the end(s) of the
catheter.
A line may be more suitable for, or preferred by, some
children – especially those who are too small for a fistula.
It does, however, have a greater risk of infection or
blockage, and needs to be looked after carefully.
»»More about inserting and looking after a
line
What happens in haemodialysis
In haemodialysis, a machine with an ‘artificial kidney’
called the dialyser cleans the blood as it passes through
the machine. Blood is pumped out of the body, through
tubes, and passes through the artificial kidney before
being returned to the body.
Your healthcare team will speak to you about these risks,
and what to look out for. They include the following.
zz Blood clots (thrombosis) – when the blood clumps
together. If this happens in a line, fistula or graft, it
may stop working.
zz Narrowing of blood vessels (stenosis) – this usually
happens slowly and your child’s dialysis team can
look for early warning signs.
zz Side-effects – including feeling tired during or after
the dialysis session, muscle cramps or low blood
pressure (hypotension), which may be sudden.
There are some other risks, depending on whether your
child has a fistula or a line.
»»Read more about risks
Each dialysis session usually lasts 3–4 hours and is
normally done during the day, although if done at home,
overnight is another option. Most children have sessions
three times a week, though they may need it more often.
Although children are connected to the machine, they can
read, do school work, play with toys or sleep.
Supporting your child
»»More about what happens in
haemodialysis
Your child’s healthcare team is there to help you. They
can provide support with your child’s education, accessing
financial benefits and planning holidays around dialysis.
There may also be help available from a team social
worker and/or psychologist.
Changing dialysis
It may be possible – or sometimes necessary – to change
the type of dialysis for your child. This may depend on your
child’s health and complications of dialysis, how he or she
is responding to dialysis, or your family’s situation. Speak
with your child’s healthcare team for more information.
Haemodialysis | Page 2
Haemodialysis can be a difficult and stressful experience
for your child and the whole family, including other children.
You and your child will learn more over time about how to
help live with dialysis.
Speaking with other families of children on dialysis can
also be a huge support.
ÎÎIf you have any concerns or need additional
support, speak with your doctor or nurse.
»»More information about supporting
your child and the future in Dialysis – an
introduction
Central venous line
What is it?
A central venous line (or ‘line’) is a long, thin tube
(catheter) that is placed into one of the large blood
vessels in the body. This is usually in the neck or chest, or
occasionally the groin.
Part of the catheter is inside the body, and part outside.
The part of the body where the catheter comes out is
called the exit site. There are one or two ports, or caps,
at the ends of the catheter, which connect to tubes for
each dialysis session.
A line can be inserted shortly before the first dialysis
session starts.
Temporary line
What happens
Your child will be moved into an operating theatre, a room
where surgery takes place.
The general anaesthetic will be given as an injection or
breathed in. When your child is asleep, the surgeon will
make a small cut in the area where your child’s catheter
will be inserted – this is normally in the chest or neck – and
carefully place the catheter into a blood vessel.
After the surgery
Your child will go back to the ward, where he or she will be
monitored by a healthcare team – this may be for one or
two days, or longer. He or she will have a dressing over the
cut. The catheter will usually be taped to his or her skin.
A temporary line is used for short-term dialysis. The line
is inserted by a surgeon/anaesthetist or nephrologist.The
catheter is inserted into a vein, and exits in the same site.
Your child may feel some effects from the anaesthesia, but
these do not usually last long. They include feeling sick
and being sick (vomiting), headache, sore throat, or feeling
dizzy or lightheaded.
Permanent line
Your nurse will give your child some medicines to help with
any pain from the surgery.
A permanent line is used for
long-term dialysis. The line is
usually inserted by a surgeon or
anaesthetist.
Risks
The catheter is inserted in the
vein and then tunnelled under
the skin to exit at a different site.
For example, if the catheter is
A haemodialysis line
inserted in the neck, it exits
on the front of the chest. This
means that the catheter cannot be seen when your child
wears a shirt or blouse. It stays secure with a cuff, which
sits under the skin. This type of catheter is sometimes
called a tunnelled cuffed catheter.
Surgery
Inserting a line
The most common complication is infection, caused by
germs entering the body. Infections are more likely in a line
than in a fistula.
A line can be inserted shortly before haemodialysis
needs to start. The procedure takes place at your child’s
paediatric renal unit, a specialised unit for babies,
children and young people with kidney conditions, which
may be in a different hospital.
The procedure usually takes 1–2 hours, though your child
will probably stay in the hospital for at least one night to
recover. You can bring a change of clothes and some toys
and books.
Preparing for surgery
Your child will be given a general anaesthetic, special
medicine so he or she can sleep through the procedure
and not feel any pain. The anaesthetist will speak to you
about the best option for your child. You will be asked to
give written consent, or permission, for the surgery.
Your child may be given antibiotic medicines to prevent
infection.
All surgery has some risks, but these are very rare.
Occasionally, children bleed from the cut. Some need to
go back to the hospital, and/or will need to take antibiotic
medicines to treat an infection.
Very occasionally, the surgery causes a puncture
wound in a lung. This may cause problems breathing
(pneumothorax), and may require surgery to treat.
Infection
ÎIf
Î your child has a fever (temperature above
38°C), this may be a sign of infection – contact
your unit straight away.
Most infections can be treated with antibiotic medicines,
which kill germs.
Sometimes, this can be septicaemia (infection in the
blood), which is more serious. In these cases, the line may
need to be removed. A new line can normally be inserted
after a few days – after the infection has cleared – and
haemodialysis can start again.
Taking care of the line
You and your child will be shown how to keep the exit site
clean to reduce the risk of infection, and to make sure the
catheter stays taped to his or her body so it does not get
dislodged or caught in clothing.
Make sure that you, your child or anyone else does
not remove or touch the ends (the ports or caps) of the
catheter. If this happens contact your renal unit.
Haemodialysis | Page 3
During dialysis
How long haemodialysis takes
and how often it is needed
Each dialysis session usually lasts 3–4 hours and is
normally done during the day. Most children have sessions
three times a week, though they may need it more often.
How dialysis works
For each dialysis session your child is connected to the
haemodialysis machine.
Before dialysis
Although children are connected to the machine, they can
read, do school work, play with toys or sleep.
Your child will need a quick assessment before each
session. The machine is then programmed especially for
your child.
Where haemodialysis takes
place
If at the hospital, a haemodialysis nurse will do these
tests and set up the machine. If at home, you or another
carer who has been trained will do this. The tests include:
zz weight – to estimate how much fluid needs to be
removed in the dialysis session
Hospital
Most of the time,
haemodialysis takes
place in a special
area in the paediatric
renal unit at hospital
(hospital HD).
Your unit may offer
transport, such as
a taxi or bus service, so your
child can travel to and from the
hospital.
zz blood pressure measurement (blood pressure
medicines are usually not taken on the morning
before dialysis)
zz temperature – to make sure your child is not too hot
or cold.
During dialysis
Child having haemodialysis
Home
Some children have haemodialysis in their home (home
HD). In the UK there are now two types of HD machines.
The one that is most commonly available is about the size
of a large chest of drawers and heavy. These machines
will require some modifications to your home in order to
work safely and effectively. There is also a smaller, mobile
machine that does not require any home modifications
but you will require more space at home to store all the
supplies. Both types of HD service may not be available at
your unit, but if you ask your consultant, it may be possible
to arrange for you to learn at another unit.
In order to undertake HD at home, some practical issues
will need to be thought about, including:
zz the availability of this service
zz whether your home can accommodate the
equipment. The machines and equipment, including
the supplies of concentrate and water, need to be
carefully stored away from children and pets
zz how far you live from the unit
zz the time needed to train you to run haemodialysis
and the time your child is likely to be on dialysis – if
it is anticipated that your child will have a kidney
transplant within 6 months, home HD may not be
beneficial
zz the age and size of your child. Some children who are
very young or small may only be suitable for hospital
HD.
If you decide to use haemodialysis at home, you will
receive lots of training and support from your unit.
Haemodialysis | Page 4
zz Your child will be connected to the machine. If he or
she has a fistula, one or two needles are inserted
into it – special gel or cream can be used to help your
child stop feeling any pain. The needle(s) are placed
in the fistula each dialysis session. If your child has a
line, the tubes will be connected to the port(s) at the
end of the catheter.
zz The machine pumps blood out of the body through
the tube. The blood passes into an artificial kidney,
which is called a dialyser. This sits outside the
machine.
zz The dialyser has a membrane that contains millions
of small holes that acts as a sieve or filter – this works
a bit like the filters in our kidneys (the glomeruli). The
dialyser is continuously bathed with a special fluid
called dialysate.
zz As blood passes through the dialyser, waste products
and salts move across the dialyser membrane into the
dialysate fluid and are safely removed from the body.
zz Excess water also filters out of the blood through the
membrane and is removed from the body. This is
called ultrafiltration.
zz The cleaned blood is then pumped back out of the
dialyser through another tube and back into the body.
Blood is pumped out of and into the body quickly – only a
small amount of blood is outside the body at any time.
A nurse – or you if at home – will measure your child’s
blood pressure throughout the session.
Although your child is connected to the machine, he or she
can read books, play games, do homework or sleep.
A newer type of ‘haemodialysis’ called haemodiafiltration
(HDF) is performed in some children’s kidney units. It uses
a similar machine but works differently to clean out the
blood and remove more toxins from it.
Medicines
After the dialysis session
Your child may receive some of his or her medicines at
the same time as haemodialysis. These are added to the
circuit.
After the session, your child is disconnected from the
machine. The nurse – or you, if at home – will take your
child’s blood pressure and temperature, and weigh him
or her to check that the right amount of fluid has been
removed.
zz Iron supplements – some children need these for
anaemia, a common problem in the blood of children
with chronic kidney disease; iron helps the body
make healthy red blood cells to carry oxygen round
the body.
zz EPO (erythropoietin) or darbepoietin – many
children need to take this hormone as a medicine,
as their kidneys are less able to make the hormone,
which also helps make red blood cells.
Further information
This is the end of the information on haemodialysis.
Further topics about kidney conditions, tests and
treatments are available on the infoKID website at
www.infoKID.org.uk.
Your notes and contact information
www.infoKID.org.uk
Version 1, January 2014. © RCPCH, BAPN and BKPA 2013, all rights reserved. Reviewed by: January 2017.
For details on any sources of information used in this topic, please contact us through our website www.infoKID.org.uk.
We take great care to make sure that the information in this leaflet is correct and up-to-date. However, it is important that
you ask the advice of your child’s doctor or nurse if you are not sure about something. This information is intended for
use in the United Kingdom, and may not apply to other countries.
Royal College of Paediatrics and Child Health (RCPCH), British Association of Paediatric Nephrology (BAPN),
British Kidney Patient Association (BKPA) and the contributors and editors cannot be held responsible for the accuracy of
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