Routine monitoring of sodium and phosphorus removal in peritoneal dialysis (PD) patients treated with continuous ambulatory PD (CAPD), automated PD (APD) or combined CAPD plus APD.
Background: Adequate removal of sodium (Na) and phosphorus (P) is of paramount importance for patients with dialysis-dependent kidney disease can easily quantified in peritoneal dialysis (PD) patients. Some studies suggest that automated PD (APD) results in lower Na and P removal. Methods. In this study we retrospectively analysed our data on Na and P removal in PD patients after implementation of a routine monitoring in 2011. Patients were stratified in those treated with continuous ambulatory PD (CAPD, n=24), automated PD (APD, n=23) and APD with one bag change (CAPD+APD, n=10). Until 2015 we collected time-varying data on Na and P removal from each patient (median 5 [interquartile range 4-8] values). Results: Peritoneal Na and P removal (mmol per 24h +/- standard deviation) was 102 +/- 48 and 8 +/- 2 in the CAPD, 90 +/- 46 and 9 +/- 3 in the APD and 126 +/- 39 and 13 +/- 2 in the CAPD+APD group (ANOVA P=0.141 and <0.001). Taking renal excretion into account total Na and P removal (mmol per 24h) was 221 +/- 65 and 16 +/- 5 in the CARD, 189 +/- 58 and 17 +/- 6 in the APD and 183 +/- 38 and 16 +/- 6 in the CAPD+APD group (P=0.107 and 0.764). Over time, peritoneal removal of Na but not that of P increased in all groups. In patients with modifications of PD treatment, Na but not P removal was significantly increased over-time. Conclusions: Overall Na and P removal were similar with different PD modalities. Individualized adjustments of PD prescription including icodextrin use or higher glucose concentration can improve Na removal while P removal is mainly determined by the dialysate volume.