Effect of bicarbonate-containing dialysate on chronic hemodialysis patients: a comparative study.

Changes in pH and blood gases were studied during hemodialysis with both acetate and bicarbonate dialysates. During acetate dialysis, PaO2 and PaCO2 decreased significantly (P less than 0.05) from 101 +/- 2 to 93 +/- 3 mmHg and from 34.4 +/- 1.0 to 31.8 +/- 0.9 mmHg, respectively, whereas during bicarbonate dialysis neither parameter changed significantly. The final pH was 7.45 +/- 0.01 during acetate dialysis and 7.50 +/- 0.02 during bicarbonate dialysis. Plasma bicarbonate rose immediately and progressively from 18.9 +/- 0.8 to 26.8 +/- 0.9 mmol/L with bicarbonate dialysis, whereas the increase was moderate, from 19.6 +/- 0.6 to 22.3 +/- 0.5 mmol/L, with acetate dialysis. These data indicate that dialysis-induced hypoxemia was prevented and correction of acidosis was more adequate with bicarbonate dialysis. During a two-year period on bicarbonate dialysis, total cholesterol, HDL-cholesterol, and triglycerides did not change significantly when compared to acetate dialysis. The most striking change was the increased tolerance to dialysis with bicarbonate dialysis, which included a 50% reduction in hypotensive episodes and muscle cramps and an almost complete absence of headache, nausea, and vomiting.