Peritoneal Sodium Mass Removal in Continuous Ambulatory Peritoneal Dialysis and Automated Peritoneal Dialysis: Influence on Blood Pressure Control

Abstract

Background/Aim: Sodium and water retention is common in peritoneal dialysis patients and contributes to cardiovascular disease. As peritoneal sodium removal depends partly on dwell time, and automated peritoneal dialysis (APD) often uses short dwell time exchanges, the aim of this study was to compare the 24-hour peritoneal sodium removal in APD and standard continuous ambulatory peritoneal dialysis (CAPD) patients and to analyze its possible influence on blood pressure control. Methods: A total of 53 sodium balance studies (30 in APD and 23 in CAPD) were performed in 36 stable peritoneal dialysis patients. The 24-hour net removal of sodium was calculated as follows: M = ViCi – VdCd, where Vd is the 24-hour drained volume, Cd is the solute sodium concentration in Vd, Vi is the amount of solution used during a 24-hour period, and Ci is the sodium concentration in Vi. Peritoneal sodium removal was compared between APD and CAPD patients. Residual renal function, serum sodium concentration, daily urinary sodium losses, weekly peritoneal Kt/V and creatinine clearance, 4-hour dialysate/plasma creatinine ratio, proportion of hypertonic solutions, net ultrafiltration, systolic and diastolic blood pressures, and need for antihypertensive therapy were also compared between the groups. Results: Peritoneal sodium removal was higher (p < 0.001) in CAPD than in APD patients. There were no significant differences in residual renal function, serum sodium concentration, urinary sodium losses, peritoneal urea or creatinine clearances, 4-hour dialysate/plasma creatinine ratio, or proportion of hypertonic solutions between groups. The net ultrafiltration was higher in CAPD patients and correlated strongly (r = 0.82; p < 0.001) with peritoneal sodium removal. In APD patients, peritoneal sodium removal increased significantly only in those patients with a second daytime exchange. The systolic blood pressure was higher (p < 0.05) in APD patients, and the proportion of patients with antihypertensive therapy was also higher in APD patients, although no significant relationship between blood pressure values and amount of peritoneal sodium removal was found. Conclusions: The 24-hour sodium removal is higher in CAPD than in APD patients, and there is a trend towards better hypertension control in CAPD patients. As hypertension control and volume status are important indices of peritoneal dialysis adequacy, our results have to be considered in the choice of the peritoneal dialysis modality.

Diálisis peritoneal automática adaptada: un método de prescripción eficaz, eficiente y seguro

“…Se ha estudiado que los pacientes en tratamiento de DPCA presentan mayor depuración de toxinas urémicas y eliminación de sodio, que aquéllos que realizan su tratamiento en DPA (3,(13)(14) .…”

Comparison of Volume Overload with Cycler-Assisted versus Continuous Ambulatory Peritoneal Dialysis

“…The short dwell times seem to be associated with significant changes in hemodynamics and BP; these changes may affect GFR (24). CCPD has also been associated with more frequent hypertension and less Na and fluid removal compared with CAPD as a result of the substantial sieving of sodium that can occur during the nocturnal short dwell phase of CCPD (4,6). The literature reports that the majority of patients on CCPD use more than five exchanges per night and have Ͻ100 mmol/d Na removal (4,5,25).…”

Similar Survival on Automated Peritoneal Dialysis and Continuous Ambulatory Peritoneal Dialysis in a Large Prospective Cohort

“…Although APD has been expected to improve survival, convincing evidence of major advantages is lacking. In addition APD has potential disadvantages compared with CAPD like a possible faster decline in residual renal function (1)(2)(3), less sodium removal (3)(4)(5)(6) and more peritoneal protein loss (6). Furthermore, APD is more expensive than CAPD.…”