Simposio
Fosforo e MBD in PD:
vecchi e nuovi protagonisti
Rimozione del fosforo e dialisi
peritoneale
Roberto Russo
Hyperphosphatemia is a predictor of
overall and CV mortality
Noordzij M et al NDT 21: 2513–2520,2006
Serum Phosphorus and Mortality in
Dialysis Patients
Ansell D et al NDT 22: 667, 2007
Serum Phosphorus and Mortality in PD Patients
Data on 7034 PD patients who attended Da Vita dialysis clinics
for at least 3 months
Mehrotra et al Perit Dial Int 27: Suppl 3, S12, 2007
Percentage achievement of the K/DOQI
guideline for bone metabolism
40%
Calcium
Phosph
CaxP
iPTH
Noordzij M et al NDT 21: 2513–2520,2006
Management of hyperphosphatemia
in PD patients
• Dietary phosphate restriction
• Removal of phosphate by dialysis
and residual renal function
• Administration of phosphate binder
Total body phosphate
bone and teeth
intracellular fluid
extracellular fluid
1%
14%
700 g
85%
Phosphate balance in dialyzed patients
Diet
1000 mg/d
7000 mg/week
Intestinal absorption
(50-70%)
Removal (HD)
600 mg/d
4200 mg/week
800 mg/session
2400 mg/ week
300-400 mg/d
2400 mg/ week
Removal (PD)
Difference
+ 1800 mg/ week
Ketteler M, Gross ML, Ritz E. Kidney Int 2005;67:s120-7
Sedlacek M et al Am J Kidney Diseases 2000; 36: 1020-1024
Bammens B et al Am J Kidney Dis 2005; 46: pp 512-519
Superior dialytic clearance of |[beta] |2-microglobulin and
p-cresol by high-flux hemodialysis as compared to peritoneal
dialysis
Phosphate clearance
• 55 L/1.73 m2 in APD 34 patients
• 66 L/1.73 m2 in CAPD 16 patients
Enevepoel P et al Kidney Int 2006; 70:794-9
Is it possible to control hyperphosphataemia
with diet?
Serum P 5.5 mg/dl
PCl 57L/week
5,5 mg/dl x 57 L / sett = 3135 mg of P - 3135/7 = 447 mg
60-64 g proteine x 14-15 mg (contenuto di P x g proteine) = 960 mg/2 = 480 mg
Rufino M et al Nephrol Dial Transplant 1998; 13(Suppl 3): 65–67
Urinary phosphate excretion
• CAPD patients urinary excretion (48.8+21.4)
represent about 40% of the total Pi removed
• Urinary Pi excretion was linearly related to
GFR values
Messa P et al Nephrol Dial Transplant 1998; 13 (Suppl 6): 43–48
Residual Renal Function and
Phosphate Levels
• Only 29% of patients with preserved RRF had
a serum phosphate concentration > 5.6 mg/dl
as compared with 44% of the anuric patients
• Residual GFR was an important predictor of
serum phosphate levels in a cross sectional
study of over 250 prevalent PD patients
Wang AYM et al Amer J Kidney Dis 2004; 43: 712-720
Urinary phosphate excretion
Bammens B et al Amer J Kidney Dis 2005; 46: 512-519
Cumulative Survival
Sopravvivenza dei pazienti in
dialisi peritoneale
With RRF
No RRF
Follow-up months
Wang AYM, Nephrol Dial Transplant 2005
Phosphate control with nocturnal HD
CHD
NHD
Mucsi I et al Kidney Int 1998
Phosphate control with nocturnal HD
Lindsay RM et al Amer J Kidney Dise 2003; 42: (Suppl 1) S24-S29
D/P Ratio of Solutes in PD
1,0
0,9
UREA
CREATININE
0,7
PHOSPHATE
D/P
0,4
8
2
4
Tempo di stazionamento (ore)
Transperitoneal phosphate transport
• Convention
• Diffusion down an electrochemical gradient
• Lymphatic convective absorption is not a
factor
Graff J et al Clin Physiol 1996; 16:291-300
Phosphate removal on PD
Daily transfer
1.5%
4.25%
0
50
100
mg
66 mg
111 mg
150
200
P < 0.001
250
300
350
Delmez JA et al Kidney Int 1982; 21: 862—867
Predictors of phosphate removal
Messa P et al Nephrol Dial Transplant 1998; 13 (Suppl 6): 43–48
Association between 24-hour UF and
percent of phosphate removed by UF
Granja CA et al Contrib Nephrol 2009; 163:198-205
Phosphate Balance in Peritoneal
Dialysis: Role of Ultrafiltration
Granja CA et al Contrib Nephrol 2009; 163:198-205
Phosphate clearance according to peritoneal
membrane transport characteristic
Sedlacek M et al Am J Kidney Diseases 2000; 36: 1020-1024
Phosphate clearance according to peritoneal
membrane transport characteristic
Badve SV et al Clin J Am Soc Nephrol 2008; 3: 1711–1717
Relation between the D/P ratios and
clearance of phosphorus and creatinine
Sedlacek M et al Am J Kidney Diseases 2000; 36: 1020-1024
Determinants of peritoneal phosphate
clearance, by linear regression
Badve SV Clin J Am Soc Nephrol 2008; 3: 1711–1717
Phosphate clearance according to peritoneal
membrane transport characteristic
Peritoneal Phosphate Clearance
60
50
CAPD
APD
49.5 49.7
42.4
40
36.4
35.6
28.9
30
20
10
0
H
HA
LA & L
Badve SV Clin J Am Soc Nephrol 2008; 3: 1711–1717
Phosphate clearance according to peritoneal
membrane transport characteristic
IPD 15x2 totale 30 L - TPD (50%) 29x1 totale 30 L
Piraino B et al Perit Dial Int 1994; 14:145-148
Peritoneal Phosphate clearances
according to PD modality
60
*
* CCPD2
Liters/week
50
40
CAPD
30
CCPD
20
10
0
Evenepoel
Sedlacek
Gallar
The impact of various NIPD cycling regimens on
phosphorus removal in chronic PD patients
5
L/1.73 m2
4
3
4,71 + 1,81
4,51 + 1,61
14 L
24 L
24 L
7 cycles of 2 L
12 cycles of 2 L
24 cycles of 1 L (Tidal
50%)
3,96 + 1,36
2
1
Juergensens P et al Int J Artif Organs 2005;28:1219-23
A comparison of clearances on tidal peritoneal
dialysis and intermittent peritoneal dialysis
IPD 15x2 totale 30 L - TPD (50%) 29x1 totale 30 L
Piraino B et al Perit Dial Int 1994; 14:145-148
Daily phosphate clearance
L/1.73 m2
Adequacy of automated peritoneal dialysis
with and without manual daytime exchange:
a randomized controlled trial
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
P = 0.68
7,6 + 2,0
CCPD
7,7 + 1,7
CCPD 2
Demetriou D et al Kidney Int 2006; 70:1649-55
Conclusions 1
• Total phosphate clearance depends on both RRF and
peritoneal clearance and may fall substantially as RRF
declines
• Phosphate clearances are limited with PD therapy
• Phosphate clearance on NIPD is inferior to that on
CAPD because of time dependent removal of
phosphate
• High flow CCPD may produce a marginal increase in
peritoneal phosphate clearance
• CCPD and CCPD2 do not appear to have major
differences
Conclusions 2
• There is a real concern that with reduction in
K/DOQI guidelines to KT/V 1.7, phosphate
removal with PD will be further compromised
• To prevent hyperphosphatemia most patients
undergoing PD require an exogenus
phosphate binder