Effects of peritoneal dialysate acidity on the net ultrafiltration and solute removal in patients on intermittent peritoneal dialysis

The effects of pH of conventional lactate-based peritoneal dialysis solutions (LPDS) on the net ultrafiltration and solute removal in intermittent peritoneal dialysis (IPD) were studied. Conventional LPDS is rendered acidic to minimize the caramelization of glucose. Fifteen stable uremic patients were put on weekly IPD with a conventional 1.5% LPDS (hourly 2 L cycle for 60 L). pH of the LPDS was raised to around 7.4 by the addition of 1.4 mmol sodium hydroxide (1 M solution) to each litre of LPDS under an aseptic condition before the commencement of dialysis. A similar study was performed with the same 15 patients but the sodium hydroxide was replaced by a similar amount of sodium chloride. The net ultrafiltration, removal of urea, creatinine, sodium, and potassium were determined and compared. Serum levels of urea, creatinine, sodium, and potassium were also measured before and after the IPD. No peritonitis was encountered during the study. The net ultrafiltration volume in the euvolemic LPDS group was greater than the acidic LPDS group although this was not statistically significant [(mean ±SD) 2526 ±910 mL and 2186 ±750 mL, respectively, p = 0.21]. The clearances of urea, creatinine, sodium, and potassium showed no differences in both groups. We concluded that the ultrafiltration, clearances of urea, creatinine, sodium, and potassium in IPD were not affected by the pH of a LPDS from our results and a larger study is warranted to see the effect of dialysate pH on the peritoneal membrane.