Effect of Kt/V on survival and clinical outcome in CAPD patients in a randomized prospective study

There has been a lack of randomized control study on the effect of Kt/V on patient outcome. This interventional study was designed to examine the effect of Kt/V on continuous ambulatory peritoneal dialysis (CAPD) patients' clinical outcome and nutritional status in a randomized prospective manner.

A total of 320 new CAPD patients with baseline renal Kt/V <1.0 were recruited from six centers in Hong Kong and were randomized into three Kt/V targets: group A, 1.5 to 1.7; group B, 1.7 to 2.0; and group C,>2.0. Kt/V and nutritional status were assessed every 6 months and dialysis prescription adjusted accordingly. Nutritional assessment included serum albumin and composite nutritional index (CNI). Patients were allowed to withdraw at the discretion of their physicians or themselves.

Total Kt/V were significantly different between groups (P = 0.000) and the difference was contributed by peritoneal Kt/V only. The overall 2-year patient survival was 84.9%. There was no statistical difference in patient survival among the three groups (2-year survival in group A, 87.3%; group B, 86.1%; and group C, 81.5%). However, there were more patients withdrawn by physicians in group A (group A, 16; group B, 7; and group C, 6; P = 0.023). Total Kt/V or Kt did not significantly affect survival after adjustment to age and diabetes. There was no difference in serum albumin, CNI scores, and hospitalization rate, but there were more patients in group A requiring erythropoietin (EPO) treatment after 1 year.

Patients with total Kt/V maintained below 1.7 had significantly more clinical problems and severe anemia but there was no difference in outcome demonstrated for patients with Kt/V maintained above 2.0 and between 1.7 and 2.0. We recommended that the minimal target of total Kt/V should be above 1.7.