Dialysate Potassium, Dialysate Magnesium, and Hemodialysis Risk

One of the fundamental goals of the hemodialysis prescription is to maintain serum potassium levels within a narrow normal range during both the intradialytic and interdialytic intervals. Considering the extraordinarily high rate of cardiovascular mortality in the hemodialysis population, clinicians are obligated to explore whether factors related to dialytic potassium removal can be modified to improve clinical outcomes. Observational studies and circumstantial evidence suggest that extreme concentrations of serum and dialysate potassium can trigger cardiac arrest. In this review, we provide an overview of factors affecting overall potassium balance and factors modulating potassium dialysate fluxes in dialysis, and we review data linking serum and dialysate potassium concentrations with arrhythmias, cardiovascular events, and mortality. We explore potential interactions between serum and dialysate magnesium levels and risks associated with dialysate potassium levels. Finally, we conclude with proposed dialytic and novel nondialytic approaches to optimize outcomes related to potassium homeostasis in patients on hemodialysis. Dialysis clinicians need to consider changes in the overall clinical scenario when choosing dialysate potassium concentrations, and an effective change in practice will require more frequent serum potassium monitoring and responsive dialysis care teams.