Effect of dialysate bicarbonate and sodium on blood pH in maintenance hemodialysis-A prospective study.

Abstract

The validity of adjusting dialysate bicarbonate based on pre-hemodialysis (HD) serum bicarbonate is unclear. There are no studies of the impact of dialysate sodium on blood pH. To understand the impact of dialysate bicarbonate and sodium on blood pH. Two hundred arterialized blood samples were obtained on the third session of HD with four configurations of dialysate: sodium (140, 137 mEq/L) and bicarbonate (38, 32 mEq/L). The correlation between pre-HD serum bicarbonate and pH was modest (r=0.6). A lower dialysate sodium (p=0.035) and a higher bicarbonate (p=0.02) associated with a higher post-HD blood pH. The frequency of pre-HD blood pH of <7.4 and a post-HD blood pH of >7.5 did not differ for samples with serum bicarbonate <22, 22-26, or >26 mEq/L. Adjusting dialysate buffer based on pre-HD serum bicarbonate is unnecessary. A higher bicarbonate and lower dialysate sodium associate with post-HD alkalemia.