The influence of automated peritoneal dialysis on the decrease in residual renal function.

Abstract

closely monitored in APD patients in order to adjust PD prescriptions and maintain adequacy. Background. Automated peritoneal dialysis (APD) has been increasingly used in recent years. Our purpose was to investigate whether the good preservation of Key words: automated peritoneal dialysis; continuous residual renal function ( RRF ) that has been reported ambulatory peritoneal dialysis; residual renal function in patients on continuous ambulatory peritoneal dialysis (CAPD) is also observed in APD. Methods. RRF was determined and compared prospectively over 1 year in two groups of peritoneal Introduction dialysis (PD) patients: 18 consecutive new patients starting on APD (12 continuous cyclic peritoneal dia- Following the initial observations by Rottembourg [1], lysis (CCPD) patients and six nightly intermittent it is now recognized that residual renal function (RRF ) peritoneal dialysis (NIPD) patients) and 18 selected is better preserved in end-stage renal disease patients patients who had started on CAPD at the same time on continuous ambulatory peritoneal dialysis (CAPD) and were matched for baseline characteristics. RRF than in those on haemodialysis. This finding has been was assessed on normalized creatinine clearance recently reviewed and confirmed by Lameire [2]. (ml/min/1.73 mO) measured before the start of PD, at Good preservation of RRF is one of the main 6 months, and at 1 year. Wilcoxon’s rank sum test was advantages of peritoneal dialysis (PD). RRF plays a used to compare diVerences between the two groups. major role in maintaining water and electrolyte balance Results. Creatinine clearance (Cl Cr ) was 6.1 ml/min in without stringent food and water intake restriction, in the APD group and 6 ml/min in the CAPD group at maintaining renal endocrine function, and in eliminatthe start of PD. The monthly rate of Cl Cr decrease was ing so-called middle molecules. Beside these clinical significantly higher in the APD group: ’0.28 ml/min vs benefits, RRF is one of the factors that determine ’0.1 ml/min (P=0.04) at 6 months and ’0.26 ml/min adequacy in PD patients. Consequently the length of vs ’0.13 ml/min (P=0.005) at 1 year. RRF decreased time PD remains adequate depends on the rate at at the same rate in patients treated with NIPD or which RRF declines. The importance of RRF preservaCCPD. The daily instilled volume of 3.86% glucose tion in PD patients has been confirmed by the dialysis solution ( l/day) was higher in APD patients CANUSA study, which found a link between PD than in CAPD patients: 2.5 vs 0 at 6 months and 1 patient outcome and adequacy indices [3]. The change year but there was no significant diVerence in ultrafil- in these indices primarily resulted from a decrease in tration rate ( l/day) between APD and CAPD patients RRF over the course of that study. The importance of at these timepoints: 0.53 vs 0.6 and 0.88 vs 0.7 respect- RRF has been recently emphasized by Bargman et al. ively. There was no diVerence between the two groups who demonstrated that it is a predictor of patient in body weight and blood pressure, which remained survival on PD independently of PD dose [4]. stable in both groups throughout the study period. Shortly after we expanded the use of automated Conclusions. RRF declined rapidly in APD patients peritoneal dialysis (APD) in our department, when whereas it was well preserved in CAPD patients. This second-generation home cyclers became available may be explained by the less stable fluid and osmotic (1995), we had the impression that some of our APD load together with the intermittent nature of APD and patients had an unusually rapid decline in RRF. We the larger use of hypertonic dialysate. RRF should be therefore undertook this study to investigate whether the good preservation of RRF previously reported in