EXPERIENCES WITH BICARBONATE SOLUTIONS IN PERITONEAL-DIALYSIS

The nowadays common peritoneal dialysis solutions contain 35 - 40 mmol/l of lactate. The continuous use of these solutions in CAPD can result in an increased blood lactate concentration with various side effects. Cellular dysfunctions may also be due to increased lactate concentrations and low pH-levels. While in many patients a 35 mmol/l lactate solution only inadequately compensates metabolic acidosis, a lactate increase up to 40 mmol/l results in negative effects due to high lactate concentrations. Various methods on the production of solutions have been applied to test the use of bicarbonate as a physiological buffer. The aim of all these variants was to avoid problems concerning production and storage, especially the precipitation of calcium and magnesium salts. To achieve this aim alkaline bicarbonate containing solutions have been mixed into acid solutions immediately before use. An alternative solution was the mixture of bicarbonate and glycylglycine to avoid the precipitation of calcium salts. Now another possibility is the use of a double-chamber-bag containing an acid and an alkaline bicarbonate containing compartment. The mixing of both solutions immediately before use avoids the precipitation of calcium and magnesium salts and results in a physiological pH-value. During a randomised open cross-over study testing this bicarbonate solution an increase of arterial bicarbonate from 21.25 mmol/l to 23.36 mmol/l was measured. The dialysis efficiency regarding ultrafiltration and urea/creatinine clearance was comparable to the lactate containing control solution. First clinical results with bicarbonate solutions in peritoneal dialysis show that technical problems can be solved and that metabolic acidosis can be compensated without reducing the dialysis efficiency.