The best evidence available to guide a policy for prescribing the dialysate sodium concentration, [DNa], comes from large randomly selected observational studies, such as the Dialysis Outcomes and Practice Patterns Study (DOPPS). These show that, after adjustment for differences in demographics and comorbidity, using a [DNa] lower than 140 mEq/L is associated with patients taking longer to recover after a dialysis treatment, worse symptoms of kidney failure, a higher score for the burden of kidney disease and worse mental and physical health-related quality of life. It is also associated with greater risks of being admitted to hospital and dying. These outcomes are more important than any medically determined surrogate outcome, such as the control of blood pressure or interdialytic weight gain. The most appropriate policy for prescribing the dialysate sodium concentration is to use a [DNa] of 140 mEq/L for the majority of patients.
