Mini-peritoneal equilibration test: A simple and fast method to assess free water and small solute transport across the peritoneal membrane.
BACKGROUND
Loss of ultrafiltration (UF) of peritoneal membrane is one of the most important causes of peritoneal dialysis failure. UF is determined by osmotic forces acting mainly across small pores (UFSP) and ultrasmall pores or free water transport. At present, only semiquantitative estimates or complicated computer simulations are available to assess free water transport. The aim of this study was to assess free water transport during a 3.86% peritoneal equilibration test lasting 1 hour. In this condition, sodium transport is mainly due to convection, allowing the estimate of ultrafiltration of small pores and then of free water transport (total UF - UFSP).


METHODS
In 52 peritoneal dialysis patients we performed a 3.86% peritoneal equilibration test (4 hours) and a 3.86% mini-peritoneal equilibration test (1 hour) and compared UF and small solute transports obtained with the two methods.


RESULTS
During the 3.86% mini-peritoneal equilibration test, UFSP and free water transport were 279 +/- 142 mL and 215 +/- 86 mL, respectively; free water transport well correlated to total UF during the 3.86% peritoneal equilibration test (r= 0.67). The groups of peritoneal transporters, categorized according to glucose dialysate ratio (D/D(0)) and to creatinine/plasma ratio (D/P(Creat)), were in good agreement for the two peritoneal equilibration tests (weighted kappa 0.62 and 0.61, respectively).


CONCLUSIONS
The 3.86% mini-peritoneal equilibration test is a simple and fast method to assess free water transport. It also gives information about total UF and small solute transports and it is in good agreement with the 3.86% peritoneal equilibration test.
La Milia
Vincenzo
V
Department of Nephrology and Dialysis, A. Manzoni Hospital, Lecco, Italy.
Di Filippo
Salvatore
S
Crepaldi
Monica
M
Del Vecchio
Lucia
L
Dell'Oro
Cesare
C
Andrulli
Simeone
S
Locatelli
Francesco
F
D000328:Adult; D000368:Aged; D015314:Dialysis Solutions / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000378:metabolism / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009997:Osmotic Pressure; D010530:Peritoneal Dialysis; D010537:Peritoneum / Q000378:metabolism*; D014867:Water / Q000378:metabolism*
D015314:Dialysis Solutions; D014867:Water