Background: Residual renal clearance has been shown to be much more predictive of survival than peritoneal clearance. There has been little data to support a target level of peritoneal clearance. A retrospective study was therefore conducted to see how the peritoneal Kt/V had affected the survival of anuric patients in our center.
Methods: Over a period of 10 years, there were 150 peritoneal dialysis patients with documented anuria. Their survival was analyzed according to their baseline peritoneal Kt/V at the time of documentation of anuria and at the time of their latest altered peritoneal dialysis (PD) prescription (subsequent Kt/V).
Results: There were 90 females and 42 diabetics. The mean age and duration of dialysis were 57.7 +/- 14.7 and 44.1 +/- 31.3 months, respectively. The 2-year and 5-year survival rates were 88.7% and 66.7%, respectively. We found that patients with baseline peritoneal Kt/V below 1.67 had poorer survival after the documentation of anuria than those above [relative risk (RR) 1.985, P= 0.01], although the baseline Kt/V was not an independent risk factors in the whole group of patients. However, such effect was mainly observed in female patients. The survival was identical between those with Kt/V above or below 1.80 (P= 0.98). Among female patients, the group with baseline Kt/V 1.67 to 1.86 had the best survival, followed by those greater than 1.86 and lowest in those below 1.67 (P= 0.0016). For patients with baseline Kt/V below 1.80, those with subsequent Kt/V above 1.76 had better survival than those below (P= 0.033).
Conclusion: Our data suggested that a negative effect of peritoneal Kt/V on survival is apparent at a level below 1.67 and there exists a limit of its effect at around 1.80. We suggested a minimal Kt/V target of 1.70 and an optimal target at 1.80 in anuric patients based on survival data. Prospective randomized study is required to confirm this finding.