A controlled trial of two bicarbonate-containing dialysis fluids for CAPD--final report.

BACKGROUND: The combination of a low pH and a high concentration of lactate which is present in most dialysis fluids is found to be cytotoxic in vitro. For these reasons it would seem logical to use a bicarbonate-containing solution and thus automatically provide a solution with a neutral pH. METHODS: A parallel, randomized, open-label, prospective 2-month trial with an optional 4 month extension was undertaken to compare two novel bicarbonate-based solutions; one containing 38 mmol/l of bicarbonate (B), and one containing a mixture of 25 mmol/l bicarbonate and 15 mmol/l of lactate (B/L), with a control solution (C) containing 40 mmol/l lactate. RESULTS: Three groups of 19 (C), 20 (B), and 20 (B/L) patients were recruited and data from approximately 55 patient months were accumulated in each group. The data show that both bicarbonate-based solutions maintain acid-base levels within the normal range, that there were no changes in any of the other blood biochemistry parameters measured in the peritoneal equilibration test or with regard to adequacy of dialysis, and that furthermore, both solutions were well tolerated. CONCLUSIONS: This study showed that either the bicarbonate or bicarbonate/lactate solutions could be utilized efficaciously in patients undergoing CAPD.

A randomized controlled trial of a bicarbonate- and a bicarbonate/lactate-containing dialysis solution in CAPD.

OBJECTIVE: To evaluate the safety and efficacy of bicarbonate- and bicarbonate/lactate-based PD fluids. DESIGN: A randomly allocated prospective controlled trial lasting eight weeks. SETTING: Five renal units in Europe. PATIENTS: Individuals who have been treated by CAPD for at least three months and who have had at least one month's therapy with 40 mmol/L lactate PD fluid. Those with recent infection, diabetes or other serious illness are excluded. Forty-seven individuals have entered the study so far. INTERVENTIONS: Patients are randomly allocated to three groups. Group 1 receive 40 mmol/L lactate dialysate, Group 2 are given 38 mmol/L bicarbonate fluid and Group 3 are tested with a 25 mmol/L bicarbonate and 15 mmol/L lactate dialysate. OUTCOME MEASURES: The primary outcome measure is the plasma bicarbonate level. Adverse events and ease of use of the two-chambered bags used by Groups 2 and 3 are also being assessed. RESULTS: To date, plasma bicarbonate levels have been the same in all treatment groups up to the end of the trial period. There are no differences in serum lactate levels. No side effects are attributable to the test fluids. The patients have managed the two-chambered bags successfully. CONCLUSION: This trial is still ongoing, but to date, neutral bicarbonate based fluids have been as effective as lactate dialysate in treating uremic acidosis.