Randomized prospective study of the effect of increased dialytic dose on nutritional and clinical outcome in continuous ambulatory peritoneal dialysis patients

Cohort studies have shown that greater urea (Kt/V) and creatinine clearance s (CCr) were associated with better survival in patients on continuous ambu latory peritoneal dialysis (CAPD). The possibility of improved patient outc ome with increased dialytic dose remains unknown. We prospectively studied over 1 year the effects of an extra 2-L bag on the outcome of 82 patients u ndergoing three daily 2-L exchanges for at least 12 months. At 1 year, 36 p atients were undergoing 6-L exchanges, whereas 30 patients underwent 8-L ex changes, The increased dialytic dose resulted in increased total weekly Kt/ V (TKt/V; 1,82 to 2.02), whereas total weekly CCr (TCCr) was maintained (63 .2 to 61.9 L/1.73 m(2)). Control patients had reduced solute clearances (TK t/V, 1.87 to 1.67; TCCr, 64.8 to 54.6 L/1.73 m(2)). The fourth bag exchange resulted in a significant increase in net ultrafiltration (0.83 to 1.51 L/ d), whereas the control group also had greater ultrafiltration (0.68 to 1.0 1 L/d) after 1 year. Although the normalized protein equivalent of nitrogen appearance (nPNA) was stable in the controls, the patients using 8-L excha nges achieved a greater nPNA (1.10 to 1.24 g/kg/d), There was no associated change in serum albumin levels (3.79 to 3.48 g/dL), The hospitalization ra te increased in the controls (0.9 to 1.8 admissions/12 mon), whereas it was unchanged in the patients using 8-L exchanges, In conclusion, a 33% increa se in dialytic prescription led to increased peritoneal and total clearance s. Despite achieving increased nPNA (13%), the serum albumin level was unch anged. However, the increased hospitalization rate observed in the controls was avoided in the group using 8-L exchanges. (C) 2000 by the National Kid ney Foundation, Inc.