Altering Bicarbonate Delivery During Hemodialysis to Affect Filtration of Indoxyl Sulfate

This is a non randomized crossover trial investigating whether changing the pattern of bicarbonate administration during hemodialysis will result in the more efficient filtration of highly protein bound solutes. The experimental group will be dialyzed with low bicarbonate dialysate for the first half of dialysis then switched over to normal bicarbonate dialysate for the second half. The control group will be dialyzed entirely with normal bicarbonate dialysate. The two groups will switch one week late and patients will serve as their own matched controls for a completely standard dialysis and one that is split into two halves with different bicarbonate concentrations.