Effect of the Peritoneal Dialysate Buffer on UL TRafil Tration: Studies in Normal Rabbits

Abstract

We studied an animal model to test the ultrafiltration capability of three different peritoneal dialysis solutions: Brand A, containing lactate and manufactured in Canada, Brand B, containing acetate and manufactured in U.S.A. and Brand C also containing acetate and manufactured in France. Solutions with 1.5 g0/o and 4.25 g0/o glucose concentrations were tested. We found no significant difference in the amount of ultrafiltration produced with the three brands when glucose concentration was 1.5 g0/o. However with glucose concentration of 4.25 g 0/o ultrafiltration was significantly lower with the Brand C-French acetate solution comparing to Brand A-Iactate solution. Brand B (acetate U.S.A.) solution produced ultrafiltration volumes that were between the other two and were not statistically significantly different from either Brand A (acetate) nor from Brand C (acetate). We concluded that the lower ultra-filtration produced by Brand C is not due to the presence of acetate buffer but to other factors operating alone or in combination with acetate. Adequate peritoneal ultrafiltration for fluid balance is one of the main factors in the success of continuous ambulatory peritoneal dialysis (CAPD). Ultrafiltration failure associated with the use of acetate buffered dialysis solution has been described frequently in France (I, 2, 3), but only occasionally in North American centres (4,5,6). It is still controversial whether acetate or some other element(s) is the factor responsible for the ultrafiltration failure observed in French patients. The first report of an international co-operative study revealed that ultrafiltration is significantly lower in patients using acetate, compared to those using lactate dialysis solutions (7). However, the second report of this study, which contained results from patients using a larger number of brands, showed that acetate may not be a responsible factor because there were patients using acetate-solutions manufactured outside France who had an ultrafiltration similar to that produced with lactate brands (8). Because of this, we chose to study in an animal model the ultrafiltration produced with solutions containing different buffers during acute experiments. This paper reports our findings.