Two variable sodium profiles and adverse effects during hemodialysis: a randomized crossover study

Intradialytic symptomatic hypotension and muscle cramps are frequent and disturbing adverse effects involving hemodialysis patients. The use of sodium profiling has been a proposed approach to preclude such events. The aim of the study was to compare the frequency of intradialytic adverse effects and changes in anthropometric and physiological variables without profiling and with two distinct sodium profiles. A prospective study randomized 22 stable hemodialysis patients to receive either a step (11 patients) or a linear (11 patients) dialysate sodium profile for 12 consecutive sessions, following a 12-session steady sodium control period. After a wash-out period of 12 sessions, the groups were crossed over for another 12-session period. Frequency of adverse effects, interdialytic weight gain, pre- and post-dialysis blood pressure were computed. The frequency of intradialytic adverse effects was significantly different between the control and either the step or linear periods (48.5%, 33.7%, and 36.0%, respectively; P < 0.001). No significant differences in interdialytic weight gain or pre-dialysis blood pressure were detected between treatment periods. The mean post-dialysis systolic blood pressure was lower in the linear period (128 +/- 21; 127 +/- 20; 123 +/- 22 mm Hg, for the control, step and linear periods, respectively; P = 0.014). Seven patients benefited from sodium profiling, yet two became more symptomatic. Overall, both sodium profiles were associated with fewer intradialytic adverse effects. Intradialytic symptomatic hypotension occurred less often with the step profile, while a tendency to fewer cramps was associated with the linear profile. However, sodium profiling may not benefit every dialysis patient and should be individually evaluated.