The impact of healthy start peritoneal dialysis on the evolution of residual renal function and nutrition parameters

The optimal time to start renal replacement therapy remains controversial. Residual renal function (RRF) and nutrition status being important prognostic factors, the present study evaluates the impact of timely start of peritoneal dialysis (PD) on their evolution. Our study used a prospective database on pre-end-stage renal disease patients at a tertiary care center. We included 18 patients who were planned to start PD at a GFR > 8 mL/min between 1 January and 31 December 1999. At the start of PD (month 0), creatinine clearance (CCr) was 11.3 +/- 3.9 mL/min, actual glomerular filtration rate (GFR) was 8.6 +/- 3.3 mL/min, and Kt/V was 1.56 +/- 0.65. The monthly declines of GFR and CCr before and after the start of PD were -0.47 +/- 0.64 mL/min (GFR) and -0.59 +/- 0.46 mL/min (CCr), and -0.06 +/- 0.30 mL/min (GFR) and -0.05 +/- 0.39 mL/min (CCr) respectively (p = 0.034 and 0.001, respectively). Before the start of PD, CCr was 21.9 +/- 4.6 mL/min (month -12) and 18.1 +/- 4.8 mL/min (month -6, p < 0.001). After the start of PD, CCr was 12.0 +/- 4.3 mL/min (month 3), 11.5 +/- 4.9 mL/min (month 6), and 13.1 +/- 5.4 mL/min (month 12, p = 0.9). Serum albumin dropped until just before the start of PD: 3.89 +/- 0.59 g/dL (month -6) and 3.78 +/- 0.51 g/dL (month -3) versus 2.56 +/- 1.60 g/dL (month 0, p = 0.04). Serum albumin then increased to 3.42 +/- 0.95 mg/dL (month 3 after the start of PD) and 3.35 +/- 0.86 mg/dL (month 6 after the start of PD, p = 0.04). In the months preceding the start of PD, the normalized protein catabolic rate (nPCR) dropped from 1.41 +/- 0.36 g/kg daily (month -6) and 1.34 +/- 0.46 g/kg daily (month -3) to 1.12 +/- 0.25 g/kg daily (month 0). It then stabilized at 1.17 +/- 0.25 g/kg daily (month 3) and 1.18 +/- 0.17 g/kg daily (months 6). One patient died owing to a cerebrovascular accident after 18 months of PD, and one was transferred to hemodialysis because of ultrafiltration failure after 19 months of PD. During 264 patient-months, 14 peritonitis episodes occurred. Of the 14 episodes, 12 resolved without complication, and the catheter was replaced in 2 episodes. After timely start of PD, the rate of RRF decline decreases. Already, at a GFR > 8 mL/min, uremia has a negative impact on nutrition parameters. Timely initiation of PD could reverse the negative evolution of albumin and stop the decline of nPCR. No severe complications related to PD were seen. In view of the important impact of RRF and nutrition on patient outcome, our data may favor an early start of PD.