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Patient
Advice and Information
Peritoneal Dialysis
by Dr Panayiotopoulos, Consultant Vascular and General Surgeon
Essex.
1. Why do patients with end stage
renal failure need dialysis?
The main functions of the kidney
are:
a.
Blood filtration of waste products
b.
Elimination of excess fluid
c.
Formation of hormones to control anaemia
When the kidney does not function well [the cause is
diabetes in 42%, hypertension in 25% and chronic infection in 10% of
the cases], water accumulates into the body, hypertension ensues
and the blood vessels harden; the waste products of metabolism
cannot be filtrated and serious complications may arise. As
there are treatments available for this type of renal insufficiency
[peritoneal dialysis or haemodialysis with an artificial kidney
machine], early intervention, before the kidneys stop to function
completely, is necessary.
2. How can dialysis be achieved?
Dialysis can be achieved by either haemodialysis
or peritoneal dialysis
 · In
haemodialysis, blood is pumped from the body [via plastic
tubes called blood lines] through the dialyzer [figure on
left], which in fact, is a bundle of tiny synthetic fibers. The
membrane of these fibers is so thin that water is allowed to pass,
and varying the pressure across the membrane allows the dialysis
machine to remove the excessive fluid buit up between treatment and
the dialysis solution to carry away the waste products. The
haemodialysis machine pumps the blood, adds anticoagulants [to thin
the blood] and regulates the purification process by the dialysis
solution. The purest blood is then returned to the patient. This
type of dialysis requires that either an arteriovenous fistula or
synthetic graft access be created. Alternatively, a double
lumen catheter inserted into one of the big veins in the neck
can be used.
-
 In peritoneal dialysis,
blood is not taken away from the body to be filtered. The
lining of the abdomen [peritoneum] is used to filter and
remove the toxic products of metabolism that accumulate. The
abdomen is filled with a special dialysis fluid [dialysate] that
stays for some time in the abdomen to allow exchange of the waste
products through the lining of the abdomen. Then, the fluid is
drained from the abdomen and is discraded. In order to achieve
this, a tube [PD Catheter, Tenchof] has to be placed in the
abdomen and stay there. Peritoneal dialysis is a flexible method,
and does not have to be done in hospital [compared to
haemodialysis]. However, it is time consuming as it has to be done
daily and it takes time time [while haemodialysis is usually done
2-3 times a week for 2-4 hours]
3. What types of peritoneal dialysis are available?
· Continuous
Ambulatory Peritoneal Dialysis [CAPD],
which is the commonest and works using gravity. A bag of warm fluid
is lifted and gravity lets it enter the peritoneal cavity.
After 40-60min, the bag is lowered to allow fluid drain out via
gravity. The bag changes are usually done 3-4 times a day with
normal routine in-between.
· Automated
Peritoneal Dialysis [APD].
It takes place during the night, with a machine [usually the
“Home Choice” which is small] warming up the fluid, pumping
it in and draining it out at scheduled intervals in preset cycles.
4. Is peritoneal dialysis the best option?
It is not easy to answer such a question, as it
depends on many variables. It certainly involves a lot of commitment
and the best decision is made by a team of people [nephrologist,
nurse, social worker etc] in respect to each individual, a joint, of
course, decision, including you. Although peritoneal dialysis is
suitable for most patients, it may not be used in people who had
previous major surgery, as the peritoneum may be scarred and not in
a prime condition to be used as filter.
5. Are there any risks in peritoneal dialysis?
There is an increased chance of developing
peritonis [inflammation of the lining], probably caused by
either infection at the exit site of the catheter or by
contamination at the exchange of bags. In such a case, you should
inform your doctor and quite often the tube may have to be removed.
-
Exit
wound infection:
It usually causes redness, soreness, local tempeture and some
times fluid oozing.
-
Peritonitis:
The signs are the presence of stomach pain, fever, sickness and
drainage of cloudy fluid.
There is also a risk the tube
to be blocked by omentum [the covering of the bowel] and stop
functioning. In such a case further intervention may be needed, to
reposition the cathter or remove the omentum. If the tube is
blocked, then it is not easy to fill the abdomen with fluid and such
an action usually causes pain. It is also not easy to drain the
fluid inserted via gravity when the bag is lowered down. Quite often
even aspiration may not be feasible.
If any of these conditions happen, do not hesitate to
ring the nurse or doctor who looks after you.
6. How is the catheter positioned in the abdomen?
This is usually done under
general anaesthaesia,
through a small
incision below the belly button.
The surgeon positions the soft tube and checks the flow through it.
The catheter is held in place by
two cuffs,
one just before the skin exit wound, the other just outside the
peritoneal cavity. Usually there are not any stitches to be removed,
as disolvable ones are been used in most cases.
The risk of the procedure is minimal and does not
take long [30-60min]; dialysis is usually carried out at the end of
the procedure to flush the peritoneal cavity and prevent the tube
from blocking. Usually 60-100ml of fluid will be left into the
abdomen and the tube will be filled with heparin solution fluid
before turning its stopcock.
7. What happens afterwards?
In most of the cases the tube is not used for 2-3
weeks. When you will come back at a pre-arranged appointment, you
will have lots to learn, as the nurses will show you how dialysis
works and will give you lots of little tips. You will have lots of
new skills to acquire , but be certain that, although it may look
difficult in the beginnning, it certainly becomes easier with time.
Remember that there is always a team of people
looking after you, eager to help you and answer all your questions.
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Please note:
A written referral from a general practitioner is helpful but is not essentially required in order to make an appointment to see a consultant specialist. |
