title: Adequacy of dialysis in automated peritoneal dialysis: a clinical experience.
abstract: 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.
authors.affiliation: Division of Nephrology, Hospital Nuestra Señora del Pino, Las Palmas de Gran Canaría, Spain.
authors.forename: A M
authors.initials: AM
authors.lastname: Fernández Rodríguez
authors.forename: N
authors.initials: N
authors.lastname: Vega Díaz
authors.forename: L
authors.initials: L
authors.lastname: Palop Cubillo
authors.forename: E
authors.initials: E
authors.lastname: Baamonde Laborda
authors.forename: A
authors.initials: A
authors.lastname: Morales Umpierrez
authors.forename: P
authors.initials: P
authors.lastname: Pérez Borges
authors.forename: M
authors.initials: M
authors.lastname: Navarro Zurita
authors.forename: C
authors.initials: C
authors.lastname: Plaza Toledano
mesh_terms: 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
chemical_list: D014508:Urea; D003404:Creatinine