Effect of fluid and sodium removal on mortality in peritoneal dialysis patients

Abstract

Background. Adequacy of peritoneal dialysis (PD) traditionally is assessed using Kt/Vurea and total creatinine clearance (TCC). However, this approach underestimates the importance of fluid and sodium removal. The aim of this study was to determine the effect of fluid and sodium removal on morbidity and mortality in PD patients. Methods. One hundred twenty-five PD patients were monitored for three years from the beginning of the treatment. The effects of demographic features, comorbidity, peritonitis rate, blood pressure, medications, blood biochemistry, peritoneal membrane transport characteristics, residual renal function (RRF), Kt/Vurea, TCC, normalized protein nitrogen appearance (nPNA), and removal of sodium and fluid on mortality were evaluated. Total and cardiovascular hospitalization rates were also recorded. A Cox proportional hazards model was used to determine factors predicting mortality. Results. In the Cox model, comorbidity, total sodium and fluid removals, hypertensive status, serum creatinine, and RRF were independent factors affecting survival. In contrast, Kt/Vurea or TCC did not affect the adjusted survivals. Total sodium and fluid removal and hypertensive status also significantly influenced the hospitalization rate. Systolic and diastolic blood pressures were negatively correlated with total fluid (P < 0.001) and sodium removal (P < 0.001). Conclusions. Together, these findings suggest that removal of sodium and fluid is a predictor of mortality in PD patients, whereas Kt/Vurea and TCC are not factors. Adequate fluid and sodium balance is crucial for the management of patients on PD.