Effect of peritoneal dialysis fluid composition on peritoneal area available for exchange in children

Background. Although conventional peritoneal dialysis fluids (PDFs), such as Dianeal(R), are non-physiological in composition, new PDFs including Physioneal(R) have a more neutral pH, are at least partially buffered with bicarbonate and, most importantly, contain low concentrations of glucose degradation products (GDPs). Methods. To evaluate the impact of new PDFs in childcare, we performed a comparative crossover study with Dianeal(R) and Physioneal(R). We examined both intraperitoneal pressure (IPP), which partly reflects pain induction, and the total pore area available for exchange, which indicates the number of capillaries perfused in the peritoneal membrane at any given moment and therefore partly reflects peritoneal dialysis capacity. The IPP was determined after inflow of 1000 ml/m(2) body surface area (BSA) of dialysate (intraperitoneal volume; IPV). The steady-state unrestricted area over diffusion distance (A(0)/Deltax, in cm(2)/cm per 1.73 m(2) BSA) was calculated from the three-pore theory. Six children were enrolled in the study. On the first day, two consecutive peritoneal equilibration tests of 90 min each were performed using first Dianeal(R) and then Physioneal(R). On the second study day, the procedure was repeated with the fluids given in the opposite order. to IPV (ml/m(2)) Results. The mean IPP normalized was significantly higher for Dianeal(R) (9.5 +/- 0.9 cm/1000 ml/m(2)) than for Physioneal(R) (7.9 +/- 1.2 cm/1000 ml/m(2), P < 0.01). The mean A(0)/Deltax was 17 +/- 4% larger with Dianeal(R) (36095 +/- 2009 cm(2)/cm per 1.73 m(2)) than with Physioneal(R) (31780 2185 cm(2)/cm per 1.73 m(2), p < 0.001; based on 24 data pairs). Conclusions. These pilot study results suggest a higher biocompatibility for Physioneal(R) than for Dianeal(R). Less inflow pain associated with Physioneal(R) induced a lower IPP reflecting enhanced fill volume tolerance, and the lower A(0)/Deltax reflected less capillary recruitment. Taken together, these results suggest that the new more biocompatible PDFs will improve peritoneal dialysis therapy, although this conclusion will require verification in extended clinical trials.