1. The peritoneal membrane
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Anatomy
• Physiology
Solutions
Concentrates
Dialysers
Membranes
Machines
Peritoneal Dialysis
Training
Oshakati hospital
2014
College
Accesses
Tubings
MD. JOSE L. RODRIGUEZ
NEPHROLOGIST
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2. Introduction
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• DEAR STUDENTS THIS TRAINING ALLOWED
YOU TO PROVIDE BETTER CARE TO THE
CHRONIC RENAL FAILURE PATIENTS .
• WE ARE SURE THAT THE OBJECTIVES OF THIS
TRAINING WILL BE ACHIEVED.
PROFESSORS……
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3. Chronic Kidney Failure
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Chronic kidney failure, also called chronic
kidney disease, describes the gradual
loss of kidney function. Your kidneys filter
wastes and excess fluids from your blood,
which are then excreted in your urine.
When chronic kidney failure reaches an
advanced stage, dangerous levels of fluid,
electrolytes and wastes can accumulate
in your body.
7.2.1 The peritoneal membrane / P. Martin
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4. The peritoneal anatomy
A sagittal section trough the
peritoneal cavity
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General facts
• Living membrane
• Reusable
• Provides lubrication for internal
organs
• Normally contains 10 - 100 cc's
fluid
• Semipermeable
• Bi-directional
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5. Sagittal view of the peritoneal
cavity during peritoneal dialysis
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7.2.1 The peritoneal membrane / P. Martin
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6. The covering layer of peritoneal
cells is called mesothelium
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Mesothelium is not just a covering layer, it consists of active
metabolic cells.
Some of the secretory activities are provoked by the dialysis
procedure.
7.2.1 The peritoneal membrane / P. Martin
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9. Peritoneal physiology
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Diffusion
RANDOM movement of solutes
across the peritoneal membrane
from an area of high concentration
to an area of low concentration
(without assistance by any flow of
fluid)
HIGH
7.2.1 The peritoneal membrane / P. Martin
low
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11. Peritoneal physiology
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Osmosis
Movement of water across the
peritoneal membrane from
an area of low concentration to
an area of high concentration.
low
7.2.1 The peritoneal membrane / P. Martin
HIGH
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14. Fluid removal is dependent on:
• the dwell time
• the peritoneum characteristics
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rapid transperitoneal absorption with decline of the osmotic
gradient in time:
Dextrose 1.5%: maximum UF rate of 9.27 mL/min
Dextrose 4.25%: maximum UF rate of 21.0 mL/min
Dextrose 1.5% removes 100-300 cc of extra water
Dextrose 2.3% removes 300-500 cc of extra water
Dextrose 4.25% removes 600-800 cc of extra water
7.2.1 The peritoneal membrane / P. Martin
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16. Peritoneal dialysis
• Diffusion
solute removal
• Convection
fluid removal
• Ultrafiltration (osmotic pressure gradient)
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The composition of PD solution is the key factor
that governs diffusion, convection as well as the
removal of fluid excess from the body
· Electrolytes correction
· Body fluid balance
· Acid-base control
· Blood purification
7.2.1 The peritoneal membrane / P. Martin
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17. Causes of Chronic Renal Failure:
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HIVAN (Namibia)
Diabetes
Hypertension
Renal vascular disease (also vascular disease)
Nephritis
Pyelonephritis & chronic UT I
Polycystic kidney disease
Renal Neoplasms
Analgesic nephropathy
Immunological disorders: Lupus, Goodpasture syndrome,
scleroderma
• Metabolic disorders: gout
7.2.1 The peritoneal membrane / P. Martin
• Nephrotic Syndrome primary or secondary
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21. Peritoneal Dialysis Catheter
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Two double-cuff Tenckhoff peritoneal
catheters: standard (A), curled (B).
7.2.1 The peritoneal membrane / P. Martin
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22. Dialysis
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Dialysis is the diffusion of solute molecules through a
semipermiable membrane, passing from higher
concentration to that of lower concentration. It is the
process of separating colloids and crystalline substances in
solution by the difference in their rate of diffusion through a
semi permeable membrane.
The purpose of dialysis is to remove endogenous and
exogenous toxins and to maintain fluid electrolyte and acidbase balance till the renal function recovers. It is a
substitute for some excretory functions of kidneys but does
not replace the endocrine and metabolic functions.
7.2.1 The peritoneal membrane / P. Martin
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23. INDICATIONS
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Uremic symptoms with neurologic
abnormalities
Persistent hyperkalemia, above 6.5 mEq/L
Blood urea level more than 50 mmol/l
Serum Creatinine more than 900 µmol/l
Severe acidosis, pH less than 7.2,
TCO2 less than 10-12 mEq/L
Hyperphosphatemia
Pulmonary edema and CCF
7.2.1 The peritoneal membrane / P. Martin
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24. Peritoneal dialysis
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Peritoneal dialysis is a technique that employs the
patient’s peritoneal membrane as a dialyzer.
Excess body water is removed by an osmotic
gradient created by the high dextrose
concentration in the dialysate; wastes are
removed by diffusion from the peritoneal
capillaries into the dialysate.
Because peritoneal dialysis is not as efficient as
hemodialysis, it must be performed daily rather
than 3 times weekly as in hemodialysis.
7.2.1 The peritoneal membrane / P. Martin
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27. 3 steps in peritoneal dialysis
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Infusion :
A sterile, dialysis solution flows into your peritoneal cavity by gravity via a catheter or
tube that has been surgically placed into the abdomen. The filling takes about 10
minutes. Once the filling is complete, the catheter is shut so that it does not leak.
Dwell :
The lining of the peritoneal cavity called the peritoneum acts as a natural filter. It lets
the waste products and excess fluids in the blood filter through into the dialysis
solution, while holding back important substances that the body needs. The length of
time varies from 3 - 6 hours. While the solution is in the body you can move about.
Drain :
The dialysis solution containing the wastes is drained again by gravity from your body
through the catheter into an empty bag. This takes about 10-20 minutes. A bag
containing sterile dialysis solution replaces the bag containing waste products. The
whole process is then repeated. Each of these replacements is called a ' Bag
Exchange'.
7.2.1 The peritoneal membrane / P. Martin
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30. 1.Continuous ambulatory
peritoneal dialysis
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It is the most commonly used method of
peritoneal dialysis. The filtration process
occurs most hours of the day. The
exchange usually take about 3 minutes
3-4 times a day and only require a
solution bag with tubing attached to it
that connects to the child’s blood
stream. It gives freedom.
7.2.1 The peritoneal membrane / P. Martin
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31. 2.Automated Peritoneal Dialysis
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a)Continuous Cyclic Peritoneal Dialysis
Continuous regimen means that the
dialysis solution is present in the
peritoneal cavity continuously, with the
exception of short significant periods
between exchange.
It uses duel lumen catheterization, i.e., 2
catheters, one for inflow and other for
outflow.
7.2.1 The peritoneal membrane / P. Martin
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32. Intermittent Peritoneal Dialysis
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-USUALLY DONE IN HOSPITAL
It means the dialysis sessions are
performed several times a week.
This technique uses one catheter
for inflow and outflow.
Flow is interrupted after both inflow
and outflow during exchange.
7.2.1 The peritoneal membrane / P. Martin
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33. PROCEDURE
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The abdomen is cleaned in preparation for surgery, and
a catheter is surgically inserted with one end in the
abdomen and the other protruding from the skin. Before
each infusion the catheter must be cleaned, and flow
into and out of the abdomen tested.
The warmed solution is allowed to enter the peritoneal
cavity by gravity and remains a variable length of time
(usually 10-15 minutes) according to the rate of solute
removal and glucose absorption in individual patients.
The total volume is referred to as dwell while the fluid
itself is referred to as dialysate.
7.2.1 The peritoneal membrane / P. Martin
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34. College
The dwell can be as much as 2.5 litres, and
medication can also be added to the fluid
immediately before infusion. The dwell
remains in the abdomen and waste products
diffuse across the peritoneum from the
underlying blood vessels. After a variable
period of time depending on the treatment
(usually 4–6 hours), the fluid is removed and
replaced with fresh fluid.
7.2.1 The peritoneal membrane / P. Martin
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The peritoneum is a large, intricately arranged serous membrane which lines the abdominal wall (parietal peritoneum) and visceral organs of the abdominal cavity (visceral peritoneum). The peritoneal cavity is the space between the parietal and the visceral layers of peritoneum. The primary purpose of the peritoneum is to provide a smooth surface over which the abdominal viscera may easily move. Normally the peritoneal cavity contains less than 100 ml of fluid, but can accommodate a 20-fold increase without patient discomfort. The peritoneal cavity is lined by a layer of living mesothelial cells on a connective tissue base which is perfused with circulatory and lymphatic vessels (1). The peritoneal membrane is semipermeable, i.e. it is highly permeable for water and smaller solutes but permeability decreases with increasing solute size and molecular weight. Transport processes take place in both directions across the peritoneal membrane: from the peritoneal microcirculation into the peritoneal cavity and vice versa, i.e. the peritoneal membrane is bi-directional.
The dialysate pulls the waste and extra fluid from the patient's blood into the peritoneal cavity. The dialysate remains in the abdomen for a specified amount of time before it is drained and replaced with fresh dialysate. The time during which the dialysate remains in the patient's abdomen is known as the dwell time. When the dialysate is drained, the wastes and extra fluids are also drained, and fresh dialysate is replaced to clean the blood. This filling and draining process is called an exchange because the dialysate that has been in the abdomen is being exchanged for new, fresh dialysate. Exchanges can be done manually or with a machine called a cycler.
The physiological basis of dialysis across the peritoneum entails the processes of diffusion, convection and osmosis.
The main factors which affect diffusion in peritoneal dialysis are solute size, concentration gradient, solute electrical charge and capillary blood flow rates. Solute size and electrical charge are also important variables regarding membrane permeability.
Osmosis is the movement of a solvent from one solution to another of higher concentration, separated by a semipermeable membrane, in order to extinguish solute concentration gradients across the membrane. The membrane is semipermeable in the sense of being impermeable to solutes in the more concentrated compartment, and being highly permeable to the solvent. Osmotic pressure is the pressure that must be applied to a solution to prevent the inflow of solvent.