Hemodialysate composition and intradialytic metabolic, acid-base and potassium changes

Area of Science:

• Nephrology
• Biochemistry
• Internal Medicine

Background:

• Dialysate composition significantly impacts patient metabolism and acid-base balance during hemodialysis.
• Acetate-based dialysates have been associated with metabolic disturbances.

Purpose of the Study:

• To compare the effects of acetate versus bicarbonate dialysates, with and without glucose, on intermediary metabolites, acid-base balance, and potassium removal.
• To determine optimal dialysate formulations for patients with limited metabolic capacity.

Main Methods:

• A four-way cross-over study comparing hemodialysis with dialysates containing acetate or bicarbonate, each with or without glucose.
• Measurement of intermediary metabolites, acid-base balance parameters, and potassium levels pre- and post-dialysis.

Main Results:

• Acetate dialysates caused significant metabolic perturbations (increased citrate, acetoacetate, beta-hydroxybutyrate; decreased pyruvate) compared to bicarbonate.
• Bicarbonate dialysates resulted in minimal metabolic changes and higher post-dialysis base equivalents.
• Glucose addition reduced metabolic changes, but less effectively than switching from acetate to bicarbonate.
• Potassium removal was higher when glucose was omitted from the dialysate, unaffected by acetate or bicarbonate.

Conclusions:

• Bicarbonate and glucose should be included in dialysate, especially for patients with compromised metabolism.
• Acetate-based dialysates can lead to significant metabolic acidosis and require careful monitoring.
• Glucose in dialysate may necessitate adjustments in dialysate potassium concentration to maintain homeostasis.