Individualized reduction in dialysate sodium in conventional in-center hemodialysis

Recent studies have focused on the association between dialysate sodium (Na⁺) prescriptions and interdialytic weight gain (IDWG). We report on a case series of 13 patients undergoing conventional, thrice-weekly in-center hemodialysis with an individualized dialysate Na⁺ prescription. Individualized dialysate Na⁺ was achieved in all patients through a stepwise weekly reduction of the standard dialysate Na⁺ prescription (140mEq/L) by 2-3mEq/L until reaching a Na⁺ gradient of -2mEq/L (dialysate Na⁺ minus average plasma Na⁺ over the preceding 3 months). Interdialytic weight gain, with and without indexing to dry weight (IDWG%), blood pressure, and the proportion of treatments with cramps, intradialytic hypotension (drop in systolic blood pressure >30mmHg) and intradialytic hypotension requiring an intervention were reviewed. At the beginning of the observation period, the pre-hemodialysis (HD) plasma Na⁺ concentration ranged from 130 to 141mEq/L. When switched from the standard to the individualized dialysate Na⁺ concentration, IDWG% decreased from 3.4%±1.6% to 2.5%±1.0% (P=0.003) with no change in pre- or post-HD systolic or diastolic blood pressures (all P>0.05). We found no significant change in the proportion of treatments with cramps (6% vs. 13%), intradialytic hypotension (62% vs. 65%), or intradialytic hypotension requiring an intervention (29% vs. 33%). Individualized reduction of dialysate Na⁺ reduces IDWG% without significantly increasing the frequency of cramps or hypotension.