Peritoneal dialysis is a type of dialysis that uses the peritoneum in the abdomen as a filtration membrane. It is used to remove excess fluid, correct electrolyte problems, and remove toxins in patients with kidney failure. It has better outcomes than hemodialysis in the first couple years. Peritoneal dialysis works through diffusion, ultrafiltration, and fluid absorption processes to transport uremic solutes and potassium out of the peritoneal capillary blood into the dialysate fluid. Factors like concentration gradients, the peritoneal surface area, and intrinsic membrane resistance affect peritoneal diffusion and fluid removal.

1. Dr Naveed Khalid

2. Type of dialysis which uses peritoneum in a persons’s
abdomen as filtration membrane
(through which fluid and dissolved substances are
exchanged with the blood.)

3. It is used to
*Remove excess fluid
*Correct elctrolyte problems
*Remove toxins with those in kidney failures.
It has better outcome then hemodialysis during first couple
of years.

4. Peritoneum is the serosal membrane that lines the
peritoneal cavity. The peritoneum is divided into 2 portions
1. The visceral peritoneum >>> which lines the gut and the
other visceras
2. The parietal peritoneum >>> which lines the walls of the
abdominal cavity

8. this model holds that the peritoneal capillary is the critical
barrier to peritoneal transport and the solute and water
movement across the peritoneal capillary is dependant on
the relative abundance of pores of different sizes.

9. 1. Large pores: radius of 20-40mm. Macromolecules such
as proteins are transported through these pores
2. Small pores: radius of 4-6mm. Small solutes such as
urea, creatinine, sodium and potassium in association
with water are transported through these.
3. Ultra pores: radius of < 0.8 mm. Responsible for
transport of water only.

10. contains the electrolytes sodium, chloride, calcium, and
magnesium
Dextrose as an osmolyte
Lactate as a buffer

11. This transport comprises of processes that take place
simultaneuosly:
1. Diffusion
2. Ultrafiltration
3. Fluid absorption

12. Uremic solutes and potassium diffuse from peritoneal
capillary blood into peritoneal fluid, whereas glucose,
lactate or bicarbonate present in the dialysate diffuse
in the opposite direction

13. Peritoneal diffusion depends on the following factors:
1. The concentration gradient
2. Effective peritoneal surface area
3. Intrinsic peritoneal membrane resistance
4. Molecular weight of the solute
5. Mass transfer area co efficient
6. Peritoneal blood flow

14. this occurs as a consequence of the osmotic gradient between
the dialysis solution and the peritoneal capillary blood; it is due
to the high concentration of glucose in the dialysis solution and
depemds on the following :
1. Concentration gradient for the osmotic agent
2. Effective peritoneal surface area
3. Hydraulic conductance of peritoneal membrane (reflects the
density of the small pores)
4. Hydrostatic pressure gradient
5. Oncotic pressure gradient
6. sieving

15. Fluid absorption from the peritoneal space occurs via
lymphatics at a relatively constant rate.
There is little or no sieving.
Fluid absorption via lymphatics reduce the efficiency of
both solute and fluid removal by peritoneal dialysis.
Fluid is also absorbed via parietal peritoneum into the
tissues of the abdominal wall, from where it is taken up by
the local lymphatics and perhaps by peritoneal
cappilaries.

16. The factors that affect the rate of fluid absorption are :
1. Intraperitoneal hydrostatic pressure
2. Effectiveness of lymphatics

17. Peritoneal equilibration test (PET)
The peritoneal equilibration test (PET) is a
semiquantitative assessment of peritoneal membrane
transport function in patients on peritoneal dialysis.
The solute transport rates are assessed by the rates of
their equilibration between the peritoneal capillary blood
and dialysate.

18. Net fluid removal
Depends on the balace between peritoneal ultrafiltrations
and peritoneal fluid absorption. In clinical practice, fluid
removal in peritoneal dialysis can be enhanced by the
following:
1. Maximising osmotic gradient
2. An osmotic agent with a higher reflection co efficient
3. Increasing urine output

19. Peritoneal clearence
Clearence for a given solute is defined as
“The volume of plasma cleared of that solute per unit time.”

20. Greater lifestyle flexibility and independence
A less restricted diet
A less restricted diet

21. Peritoneal Dialysis might not work if patient have
Extensive surgical scars inabdomen
A large area of weakened abdominal muscle (hernia)
Limited ability to care for himself, or a lack of caregiving
support
Inflammatory bowel disease or frequent bouts of
diverticulitis

22. Infections
Weight gain
Hernia
Inadequate dialysis