Clinical application of sodium profiling in the treatment of intradialytic hypotension.

BACKGROUND: Intradialytic hypotension is mainly induced by the removal of extracellular sodium during dialysis, which impairs intravascular fluid refilling and reduces blood volume. To counter this complication we tested a new kind of profiled hemodialysis (PHD) consisting of the intradialytic modulation of dialysate sodium concentration according to individual profiles set up using a new mathematical model for intradialytic solutes and water kinetics. The clinical aim of this PHD is to stabilize blood pressure maintaining higher blood volume values than standard dialysis treatments. We clinically validated PHD in comparison with constant dialysate sodium dialysis (CHD).
METHODS: Twenty hypotensive dialysis patients underwent one PHD and one CHD session maintaining the same dialysis length, sodium mass removal and body weight decrease. A new mathematical model was used to define both the dialysate sodium profiles for PHD and the constant dialysate sodium for CHD. Percent blood volume variation (Crit-line), mean blood pressure, heart rate, cardiac output (Doppler-echocardiography) were monitored intradialitically.
RESULTS: Cardiovascular stability improved on PHD as compared with CHD sessions; blood volume and cardiac output during PHD showed a lower decrease than on CHD, the differences statistically significant (from 30' and 60' respectively). Mean blood pressure was, at all time intervals, more stable on PHD than on CHD and was accompanied, on PHD, by a lower heart rate increase (differences statistically significant).
CONCLUSIONS: This study shows that PHD performed using dialysate sodium profiles elaborated by our mathematical model obtains, in hypotensive patients, a higher hemodynamic intradialytic stability than CHD, probably due to a higher stabilization of blood volume.