Background: Recent studies have shown an association between small solute clearance and patient survival. Thus far, little attention has been paid to the potential effects of fluid overload. The aim of this study was to determine the relative importance of baseline patient and treatment characteristics to mortality and technique failure in patients starting peritoneal dialysis.
Methods: One hundred and eighteen consecutive new patients were included in this prospective multicenter cohort study. Cox proportional hazards regression was used to predict mortality and technique failure.
Results: There were 33 deaths and 44 technique failures. The two-year patient survival was 77%, and the two-year technique survival was 64%. Age, systolic blood pressure, and the absolute quantity of small solutes removed at baseline were independent predictors of mortality. A one-year increase in age was associated with a relative risk (RR) of death of 1.05 (95% CI, 1.01 to 1.09) and a 10 mm Hg rise in systolic blood pressure, with a RR of 1.42 (95% CI, 1.17 to 1.73). The removal of 1 mmol/week/1.73 m2 of urinary and dialysate creatinine was associated with a RR of death of 0.95 (95% CI, 0.92 to 0.98) and 0.93 (95% CI, 0.89 to 0.98). The removal of urea had a similar association with the RR of death. Predictors for technique failure were urine volume, peritoneal ultrafiltration, and systolic blood pressure.
Conclusions: Dialysate solute removal was an independent predictor of mortality. The association between systolic blood pressure and mortality shows that the maintenance of fluid balance and the removal of small solutes deserve equal attention.