Short-term effects of bicarbonate/lactate-buffered and conventional lactate-buffered dialysis solutions on peritoneal ultrafiltration: a comparative crossover study

Background. This study was designed to compare the effects of a conventional lactate-based peritoneal dialysis (PD) solution (D) and a new biocompatible bicarbonate/lactate-based solution with a low concentration of glucose degradation products (P) on peritoneal ultrafiltration (UF) and other peritoneal membrane indices. Methods. Twenty-six stable, prevalent PD patients were enrolled in this prospective study. They sequentially underwent 3 months of therapy with the D solution and 3 months with the P solution in a randomized order. Daily, overnight and 4-h UF on PET were measured and other peritoneal membrane indices were also assessed using PET with 2.27% glucose solution. Results. Twenty-one patients successfully completed the study. The mean daily peritoneal UF with D was 1324 +/- 602 ml and 881 +/- 633 ml with P (P < 0.001) and this lower daily UF of 443 ml (95% CI 275-610 ml) with P was associated with a similarly lower daily total fluid removal of 394 ml (95% CI 210-577 ml), as urine volume did not differ between D and P. The decrement in UF with the P solution was reversible. There were no significant differences in other peritoneal membrane indices (D/P creatinine, D/D(0) glucose, 4-h UF at PET, weekly creatinine clearance, weekly urea Kt/V) or blood pressure and body weight between the solutions whereas calculated peritoneal fluid absorption rate was significantly higher with the P than with the D solution. Conclusion. This study shows that the daily UF with the P solution may be lower than with the D solution. The mechanism for this short-term and reversible effect that conceivably reflects differences in biocompatibility is not clear although our results implicate that the peritoneal fluid absorption rate may differ between the two solutions.