Clinical experience with two physiologic bicarbonate/lactate peritoneal dialysis solutions in automated peritoneal dialysis

Background. Patients on automated peritoneal dialysis (APD) usually receive larger volumes of dialysis solution and more frequent, shorter exchanges than patients on continuous ambulatory peritoneal dialysis (CAPD), and therefore are likely to derive greater benefit from more physiologic solutions. Methods. Peritoneal dialysis solutions containing 25 mmol/L bicarbonate and either 10 or 15 mmol/L lactate were compared with standard lactate solutions (35 or 40 mmol/L) in two prospective, open-label studies of patients on APD. Each study included a 2-week baseline period (lactate solution), a 6-week treatment period (bicarbonate/lactate solution), and a 2-week follow-up period (same lactate solution as baseline). Biochemical analyses and assessments of vital signs and safety parameters were conducted at baseline, every 2 weeks during treatment, and at the end of the follow-up period. A product use questionnaire was administered in one study at the end of treatment. Results. A statistically significant rise in plasma bicarbonate (approximately 2 mmol/L) occurred when patients switched from a lactate solution to the bicarbonate/lactate solution with equimolar buffer concentration (P<0.001 for each solution). Plasma bicarbonate decreased by 1.16 mmol/L after a switch from lactate 40 mmol/L to bicarbonate/lactate 35 mmol/L (P<0.001). When patients switched to bicarbonate/lactate 35, the majority of individual venous plasma bicarbonate values were in the normal range. A switch from a lower calcium (1.25 mmol/L) lactate solution to a higher calcium (1.75 mmol/L) lactate/bicarbonate solution resulted in a statistically significant rise in serum calcium (0.06 mmol/L, P<0.018). The product use questionnaire revealed improvements in symptoms, including reduced pain on infusion. Conclusion. Bicarbonate/lactate solutions may be used safely and effectively in patients on APD. The availability of 2 formulations with different buffer and calcium content provides flexibility for the control of acidosis as well as calcium balance.