Bicarbonate,L-Lactate and D-Lactate Balance in Intermittent Peritoneal Dialysis

Abstract

Systemic acid-base values and bicarbonate and lactate balance were measured during dialysis in seven patients on chronic intermittent peritoneal dialysis (IPD). Dialysate contained 40 mM lactate, including 20 mM D-Iactate and 20 mM L-Iactate. Mean predialysis plasma bicarbonate concentration was 22 mM and rose to 25 mM after dialysis. The average net alkali gain during dialysis, calculated as lactate gain minus bicarbonate loss, was 80 mmoles/ treatment or 34 mmoles/day. There was considerable variability in alkali gain between patients and between treatments in the same patient. The major factors influencing alkali gain were peritoneal solute clearance and dialysate effluent volume, or ultrafiltration. Both in the balance study, and in a shorter study comparing the effects of consecutive 4.25% or 0.5 % glucose exchanges on net alkali gain, the authors demonstrated that increasing ultrafiltration reduced net alkali gain by about 26 mmoles/liter ultrafiltrate. D-Iactate appears to be quantitatively as important as Llactate in bicarbonate generation. Further longitudinal studies are required to define the relationship between net alkali gain, dietary hydrogen-ion generation and blood acid-base values.