Adequacy of dialysis in automated peritoneal dialysis: a clinical experience.
OBJECTIVE
To compare the peritoneal clearances of urea and creatinine in continuous ambulatory peritoneal dialysis (CAPD) with three types of automated peritoneal dialysis (APD): continuous cycling peritoneal dialysis (CCPD), 50% tidal peritoneal dialysis (TPD), and 25% TPD and to assess the usefulness of the peritoneal equilibration test (PET) in predicting peritoneal clearances in overnight APD.


METHODS
Eleven uremic patients (mean age 44.5 +/- 15.45 years with a mean time on dialysis of 42.63 +/- 25.62 months) were included in the study.


METHODS
PET for urea and creatinine following Twardowski's method. Peritoneal clearances for urea and creatinine CAPD: samples of blood and dialysate within 24 hours. APD: blood mean levels of urea and creatinine before and after nighttime dialysis. Dialysate: urea and creatinine in nocturnal and daytime dialysate.


RESULTS
Peritoneal clearance of creatinine was 38.14 +/- 9.99 L/week/1.73 m2 in CAPD, 44.28 +/- 12.4 L/week/1.73 m2 in CCPD, 50.07 +/- 17.86 L/week/1.73 m2 in 50% TPD (p < 0.05) and 40.18 +/- 6.65 L/week/1.73 m2 in 25% TPD. Peritoneal clearance of urea improved significantly in the three modalities of APD: 51.91 +/- 12.58 L/week/1.73 m2 in CAPD; 66.7 +/- 9.9 L/week/1.73 m2 in CCPD (p < 0.05); 76.3 +/- 14.5 L/week/1.73 m2 in 50% TPD (p < 0.001) and 64.4 +/- 11.4 L/week/1.73 m2 in 25% TPD (p < 0.05). The dialysate/ plasma (D/P) ratio of creatinine at 30, 60, 120, 180, and 240 minutes showed significant correlation with nighttime APD clearance. Nevertheless, only the D/P ratio of urea at 30, 60, and 120 minutes correlated with overnight APD clearance.


CONCLUSIONS
A remarkable improvement was observed with APD regarding the clearance of urea mainly when 50% tidal peritoneal dialysis was used, whereas it was less noticeable in the clearance of creatinine. The PET is a helpful tool in predicting overnight peritoneal clearances of creatinine but it is less useful in predicting urea clearance.
Fernández Rodríguez
A M
AM
Division of Nephrology, Hospital Nuestra Señora del Pino, Las Palmas de Gran Canaría, Spain.
Vega Díaz
N
N
Palop Cubillo
L
L
Baamonde Laborda
E
E
Morales Umpierrez
A
A
Pérez Borges
P
P
Navarro Zurita
M
M
Plaza Toledano
C
C
D000328:Adult; D003404:Creatinine / Q000378:metabolism; D005260:Female; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D007676:Kidney Failure, Chronic / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000379:methods; D010531:Peritoneal Dialysis, Continuous Ambulatory; D010537:Peritoneum / Q000378:metabolism; D014508:Urea / Q000378:metabolism
D014508:Urea; D003404:Creatinine