title: What is the link between poor ultrafiltration and increased mortality in anuric patients on automated peritoneal dialysis? Analysis of data from EAPOS.
abstract: BACKGROUND
  Primary analysis of the European Automated Peritoneal Dialysis Outcomes Study (EAPOS) found that patients with daily ultrafiltration (UF) below a predefined target of 750 mL at baseline experienced increased mortality and continuing low UF over 2 years.
  
  
  METHODS
  Multicenter, prospective observational study of prevalent, functionally anuric patients on automated peritoneal dialysis (APD) treated to predefined standards.
  
  
  METHODS
  Secondary data analysis to determine clinical covariates that might support a link between poor UF and outcome, including pattern of comorbidity, prescription, nutrition as determined by Subjective Global Assessment (SGA), membrane function, and blood pressure (BP). Ultrafiltration was treated as a categorical (comparing patients above and below target at baseline) and continuous dependent variable in univariate and multivariate regression. The relationship between BP and survival was also explored.
  
  
  RESULTS
  Of 177 patients recruited from 28 centers across Europe, 43 were below the UF target at baseline. Compared to those above target, there were no differences in the spread of comorbidity, type of APD prescription, SGA, BP, hemoglobin, HCO3, or parathyroid hormone, at baseline or at any later time. At baseline, plasma calcium and, at 12 months, plasma phosphate were lower in the low UF group. There was a weak positive correlation between baseline systolic or diastolic BP and UF, which remained on multivariate analysis but accounted for just 9% of the variability in BP. There was no clear relationship between baseline BP and survival, although, if anything, low BP was associated with earlier death. Poor UF was associated with lower mean dialysate glucose concentration during the first 4 months and with consistently worse membrane function.
  
  
  CONCLUSIONS
  The increased mortality associated with poor UF is likely multifactorial and not easily explained by clear differences in comorbidity, nutritional state, or other indices of treatment at baseline. The lower plasma phosphate suggests a subsequent fall in appetite. Poor BP control is unlikely to be the explanation, and a link between lower BP, reduced UF, and earlier death is suggested. Failure to achieve adequate UF due to worse membrane function remains an important and potentially reversible or preventable cause.
authors.affiliation: Department of Nephrology, University Hospital of North Staffordshire, Princes Road, Hartshill, Stoke-on-Trent ST4 7LN, United Kingdom. SimonDavies1@compuserve.com
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Davies
authors.forename: Edwina A
authors.initials: EA
authors.lastname: Brown
authors.forename: Werner
authors.initials: W
authors.lastname: Reigel
authors.forename: Elaine
authors.initials: E
authors.lastname: Clutterbuck
authors.forename: Olof
authors.initials: O
authors.lastname: Heimbürger
authors.forename: Nicanor Vega
authors.initials: NV
authors.lastname: Diaz
authors.forename: George J
authors.initials: GJ
authors.lastname: Mellote
authors.forename: Javier
authors.initials: J
authors.lastname: Perez-Contreras
authors.forename: Renzo
authors.initials: R
authors.lastname: Scanziani
authors.forename: Christian
authors.initials: C
authors.lastname: D'Auzac
authors.forename: Dirk
authors.initials: D
authors.lastname: Kuypers
authors.forename: Jose C
authors.initials: JC
authors.lastname: Divino Filho
mesh_terms: D001002:Anuria / Q000401:mortality*; D001331:Automation; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010530:Peritoneal Dialysis / Q000401:mortality / Q000706:statistics & numerical data*; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D001786:Blood Glucose