Changes in Serum Bicarbonate Levels Caused by Acetate-Containing Bicarbonate-Buffered Hemodialysis Solution: An...

Fresenius Medical Care's NaturaLyte dialysate has been associated with increased risk of sudden cardiac death by causing metabolic alkalosis from its acetate content based on retrospective data using pre-dialysis bicarbonate levels only. The study objective was to measure inter/intra-dialytic changes in serum bicarbonate and degree of alkalosis conferred by varying concentrations of NaturaLyte bicarbonate dialysate. Thirty-nine hemodialysis patients were divided into four groups based on prescribed bicarbonate dialysate concentrations; Group 1 (N = 9): 30-32 mEq/L, Group 2 (N = 5): 33-34 mEq/L, Group 3 (N = 10): 35-36 mEq/L, Group 4 (N = 15): 37-40 mEq/L. Serial (pre-dialysis, immediate post-dialysis, 2 h post-dialysis, and 68 h post-dialysis) bicarbonate levels were measured. Mean pre-dialysis serum bicarbonate levels (representing 44 h post-dialysis levels) in all four groups were not statistically different. Pre-dialysis and 68 h post-dialysis bicarbonate levels in each group were also not significantly different. However, immediate post-dialysis and 2 h post-dialysis bicarbonate levels were significantly increased in all four groups proportional to dialysate dose. There was statistically significant inter-group bicarbonate level difference (P < 0.05) except between the first and second (P = 0.43) and second and third (P = 0.07) groups in the immediate post-dialysis period. Similar results were obtained for the 2 h post-dialysis period. High bicarbonate dialysate causes large and rapid fluctuations in serum bicarbonate levels during the intra/inter-dialytic period, which returns to baseline within 44 to 68 h after dialysis. This refutes the necessity to correct pre-dialysis acidosis with high bicarbonate dialysate since rapid equilibration is likely to occur and unnecessarily exposes patients to large shifts in their acid base balance.