Sodium removal in peritoneal dialysis: the role of icodextrin and peritoneal dialysis modalities

One of the main goals of dialysis is the control of extracellular volume, because inadequate sodium and fluid removal result in fluid overload and increased mortality. In the present study, we evaluated the roles of continuous ambulatory peritoneal dialysis (CAPD), continuous cycling peritoneal dialysis (CCPD), and the use of icodextrin on sodium removal in 29 patients (n = 18 on CAPD, n = 11 on CCPD). Daily removal of sodium by each modality and dialysis adequacy by Kt/V and creatinine clearance were evaluated. A significantly higher amount of sodium was removed in CAPD patients than in CCPD patients, although peritoneal dialysis clearances were lower in CAPD, and no difference in daily ultrafiltration was observed between the modalities. In the CAPD group, patients using icodextrin for the long dwell showed significantly increased 24-hour sodium removal (218 +/- 65 mmol/L) as compared with patients not using icodextrin (96.3 +/- 58 mmol/L, p < 0.001); they also showed increased daily ultrafiltration (1685 +/- 302 mL vs. 717 +/- 440 mL, p < 0.001). In the CCPD group, 8 patients were using icodextrin for the long dwell, and they showed significantly increased sodium removal only for the day exchange (43 +/- 49 mmol/L) as compared with patients not using icodextrin (-60 +/- 6, p < 0.001). Hypertension was less common in the CAPD patients than in the CCPD patients. These results indicate that CAPD is a more efficient modality than CCPD for sodium removal. Icodextrin is an effective tool not only for increasing adequacy, but also for removing more sodium in both modalities.