PD membrane failure

Question 1

What is Peritoneal Solute Transfer Rate? (PSTR)

Answer 1

Rate of solute transfer across the membrane

described as;
a. diffusion capacity
b. mass transfer area coefficient (MTAC)
- maximal rate of clearance by diffusion
c. solute dialysate-to-plasma concentration ratio (D/P ratio)

ISPD peritoneal membrane dysfunction

Question 2

How to identify Peritoneal Solute Transfer Rate (PSTR) ?

Answer 2

1. from 4hrs PET
2. use 2.5% / 4.25% glucose solution
3. creatinine as index solute

Question 3

Affects on fast PSTR

Answer 3

1. lower survival
2. lower UF
3. increase net fluid reabsorption

Solution
1. icodextrin
2.prescribe higher glucose conc

Question 4

low UF capacity

Answer 4

1. net UF from 4h PET < 400ml (with 4.25% solution) or < 100ml (with 2.3% solution)
   AND / OR
2. daily UF is insufficient to maintain adequate fluid status

Question 5

Factors that determine the efficiency of water transport

Answer 5

1. peritoneal osmotic conductance to glucose (OCG)
2. rate of glucose diffusion from dialysate to blood
3. peritoneal lymph flow
4. glucose conc at the start of dwell

Question 6

PET test (peritoneal Equilibration test)

Answer 6

peritoneal membrane clearance and UF characteristic
by measuring
- dialysate to plasma ratio (D/P ratio) of creatinine and glucose
at specific time
under standard condition

Question 7

How to perform PET test?

Answer 7

0 hr
2 hr
4 hr

dialysate urea / creat / glu 0,2,4 hrs
blood urea / creat / glu 2hrs

Question 8

Sodium sieving phenomenon

Answer 8

consequence of dissociation between the amount of water and sodium transported over the peritoneal membrane.

decrease of dialysate [Na] (dip) during 1st hour of hypertonic dwell

Question 9

causes of membrane dysfunction

Answer 9

1. type 1: fast PSTR
2. type 2: low osmotic conductance to glucose
3. type 3: low effective peritoneal surface area
4. type 4: High Total Peritoneal Fluid Loss Rate

Question 10

Type 1: fast PSTR

Answer 10

Def:
D/P ratio > 0.65 (>0.81)

causes: (local inflammation)
a. membrane inflammation cause large effective vascular surface area
b. neovascularization
*post peritonitis

mx:
use short dwell
change to APD
icodextrin with long dwell
rest peritoneum for 2-3 month

Question 11

Type 2: low osmotic conductance to glucose

Answer 11

def:
sodium dip at 60min < 5mmo/l
sodium sieving ratio < 0.07 with 4.35% glucose (low)

causes:
a. functional alteration of aquaporin
b. aquaporin deficiency

*can happen at start of PD

mx:
? steroid
conversion to HD

Question 12

type 3: low effective peritoneal surface area

Answer 12

diffuse hypopermeability of the peritoneal membrane results in impairment of both solute transport and ultrafiltration

causes:
a. structural alteration in peritoneum - fibrosis —> EPS

*happen over years on PD

Mx:
conversion to HD

Question 13

typer 4: High Total Peritoneal Fluid Loss Rate

Answer 13

an increase in the rate of bulk fluid absorption from the peritoneal cavity into lymphatics and into the local tissues

= high ‘effective lymphatic absorption rate’ (due to lymphangiogenesis)

Mx:
conversion to HD