Ultrafiltration volume by once-weekly hemodialysis is a predictor of technique survival of combination therapy with peritoneal dialysis and hemodialysis.

Overhydration is a major cause of technique failure of peritoneal dialysis (PD). Hence, we investigated the impact of ultrafiltration (UF) volume by once-weekly hemodialysis (HD), excess volume beyond their dry weight, on technique survival of PD and HD combination therapy (PD+HD). Forty-six anuric PD+HD patients were divided into three groups according to baseline UF volume by HD: low-UF (<mean - 1SD), middle-UF (≥mean - 1SD and <mean + 1SD), and high-UF (≥mean + 1SD). High-UF group showed larger extracellular water normalized to height (P = .038) and longer HD sessions (P < .001) compared with low-UF group, whereas low-UF group was older than middle-UF group (P = .001). Technique survival rate was significantly lower in high-UF group than in low and middle-UF groups (P < .001), and the rates at 44 months were 80%, 90%, 20% in low, middle, and high-UF groups, respectively. Chronic overhydration was the leading cause of technique failure for all. This study suggests that fluid overload remains a major cause of technique failure of PD even after once-weekly HD is added.