Objective: To study the influence of residual renal function (RRF) on different parameters of the renal substitutive treatment offered by peritoneal dialysis. Methods: We analyzed the impact of RRF on dialysis dose, nutrition parameters, anemia and phosphocalcic metabolism in 37 patients with end-stage renal disease (ESRD) treated by continuous ambulatory peritoneal dialysis (CAPD). Analytical controls were done every 6 months after an initial assessment at the end of the first month of treatment. Multiple lineal regression models were used as the statistical method to analyze the influence of RRF on different theoretically dependent factors. RRF was calculated as a mean of creatinine and urea clearances. Three observations per patient were used: one at the end of the first month of treatment; a final one at the end of follow-up (mean time 24.2 ± 11.4 months), and at a mean time between them (13.4 ± 6.7 months), with a final number of 111 observations. Results: Dialysis dose: RRF was the most important factor in terms of creatinine clearance (r² = 0.94; β = 0.999), KT/V (r² = 0.68; β = 0.819) and β₂-microglobulin levels (r² = 0.46; β = –0.489). Nutrition parameters: RRF was a determinant factor for normalized protein catabolic rate (r² = 0.53; β = 0.471), percent lean body mass (r² = 0.45; β = 0.446) and albumin levels (r² = 0.25; β = 0.229). Anemia: RRF was the most important factor when studying hemoglobin levels (r² = 0.28; β = 0.407). Phosphocalcic metabolism: Between the analyzed factors, RRF was the only one which reached significance on serum phosphate levels (r² = 0.19; β = –0.594). RRF did not show any relationship with either calcium or PTH levels. Conclusions: Independent of other factors, RRF in CAPD is positively and directly related to dialysis dose, β₂-microglobulin levels, nutrition parameters (albumin, normalized protein catabolic rate and percent lean body mass, hemoglobin and serum phosphate levels.

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, 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.

♦ Objective Conventional continuous ambulatory peritoneal dialysis (CAPD) in patients without residual renal function and with high solute transport is associated with worse clinical outcomes. Automated peritoneal dialysis (APD) has the potential to improve both solute clearance and ultrafiltration in these circumstances, but its efficacy as a treatment modality is unknown. The European Automated Peritoneal Dialysis Outcomes Study (EAPOS) is a 2-year, prospective, European multi-center study designed to determine APD feasibility and clinical outcomes in anuric patients. The present article describes the baseline data for patients recruited into the study. ♦ Design All PD patients treated in the participating centers were screened for inclusion criteria [urinary output < 100 mL/24 h, or residual renal function (RRF) < 1 mL/min, or both]. After enrollment, changes were made to the dialysis prescription to achieve a weekly creatinine clearance above 60 L per 1.73 m2 and an ultrafiltration rate above 750 mL in 24 hours. ♦ Setting The study is being conducted in 26 dialysis centers in 13 European countries. ♦ Baseline Data Collection The information collected includes patient demographics, dialysis prescription, achieved weekly creatinine clearance, and 24-hour ultra-filtration (UF). ♦ Results The study enrolled 177 anuric patients. Median dialysis duration before enrollment was 22.5 months (range: 0 – 285 months). Mean solute transport measured as the dialysate-to-plasma ratio of creatinine (D/PCr) was 0.74 ± 0.12. Patients received APD for a median of 9.0 hours overnight (range: 7 – 12 hours) using a median of 11.0 L of fluid (range: 6 – 28.75 L). Median daytime volume was 4.0 L (range: 0.0 – 9.0 L). Tidal dialysis was used in 26 patients, and icodextrin in 86 patients. At baseline, before treatment optimization, the weekly mean total creatinine clearance was 65.2 ± 14.4 L/1.73 m2, with 105 patients (60%) achieving the target of more than 60 L/1.73 m2. At baseline, 81% of patients with high transport, 69% with high-average transport, and 40% with low-average transport met the target. At baseline, 70% of patients with a body surface area (BSA) below 1.7 m2, 60% with a BSA of 1.7 – 2.0 m2, and 56% with a BSA above 2.0 m2 achieved 60 L/1.73 m2 weekly. Median UF was 1090 mL/24 h, and 75% of patients achieved the UF target of more than 750 mL/24 h. ♦ Conclusion This baseline analysis of anuric patients recruited into the EAPOS study demonstrates that a high proportion of anuric patients on APD can achieve dialysis and ultrafiltration targets using a variety of regimes. This 2-year follow-up study aims to optimize APD prescription to reach predefined clearance and ultrafiltration targets, and to observe the resulting clinical outcomes.

We conducted a retrospective study with 750 peritoneal dialysis (PD) patients in a Spanish multicenter registry between 1993 and 1999 to analyze comorbidity and mortality in type 1 diabetes (T1D), type 2 diabetes (T2D) and nondiabetic (ND) patients. 163 patients (21.7%) were diabetic – 96 T1D (58.8%) and 67 T2D (42.2%) – while 587 were not (78.3%). Different comorbidity factors such as the presence of cardiovascular disease, age over 70 and dyslipidemia at the start of PD were analyzed as well as the incidence of peritonitis, the peritonitis-free interval, need for hospitalization, mortality rate, early mortality rate, survival curves (log rank) and the impact factor (Cox) on mortality for the different variables. The comorbidity index (number of comorbidity factors when starting the treatment) and the peritonitis incidence were higher for T2D. Hospitalization rates were similar, but mortality rates were higher for T2D and early mortality rates (death during the 1st year of treatment) were higher for T1D. The actuarial survival curves showed a higher mortality for T2D with no differences between ND and T1D after adjustment for age. The mortality odds ratio was 1.78 for T2D and 1.13 for T1D, differences which were not significant after adding age over 70 and cardiovascular disease to the variables analyzed. Our results show that associated comorbidity is the most important difference between ND, T1D and T2D. While cardiovascular comorbidity is responsible for the higher percentage of early mortality found in T1D when compared to ND, both age and cardiovascular disease are responsible for the higher comorbidity and mortality found in T2D.

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