WHAT IS THE LINK BETWEEN POOR ULTRAFILTRATION AND INCREASED MORTALITY IN ANURIC PATIENTS ON AUTOMATED PERITONEAL DIALYSIS? ANALYSIS OF DATA FROM EAPOS

University Hospital of North Staffordshire, 1 Stoke on Trent; Charing Cross Hospital, 2 London, UK; Klinikum Darmstadt, 3 Darmstadt, Germany; Hammersmith Hospital, 4 London, UK; Karolinska University Hospital, 5 Huddinge, Sweden; Hospital Universitario Dr. Negrin, 6 Las Palmas, Spain; Adelaide & Meath Hospital, 7 Dublin, Ireland; Hospital General Universitario, 8 Alicante, Spain; Ospedale Provinciale Desio, 9 Desio, Italy; Hôpital Européen Georges Pompidou, 10 Paris, France; U.Z. Gasthuisberg, 11 Leuven; Baxter Renal Division Europe, 12 Brussels, Belgium Correspondence to: S.J. Davies, Department of Nephrology, University Hospital of North Staffordshire, Princes Road, Hartshill, Stoke-on-Trent ST4 7LN, United Kingdom. SimonDavies1{at}compuserve.com 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. Setting: 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, HCO 3 , 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