#6844 MONITOR SWITCHING-INDUCED VARIATIONS IN CONDUCTIVITY AND PLASMA SODIUM DURING HEMODIALYSIS SESSIONS

Abstract

Abstract Background and Aims Until the advent of the new monitors with sodium modules, the differences between prescribed and actual sodium have been little studied. And most dialysis centers have a fixed sodium prescription. However, the sodium gradient during sessions is one of the key factors in its balance in hemodialysis patients. Predialysis plasma sodium has an important interindividual but not intraindividual variability, which supports the hypothesis of reference sodium (setpoint). This work aimed to compare the impact of switching from the 5008 Cordiax monitor to the new 6008 Cordiax monitor on the actually measured conductivity and initial and final plasma sodium. Method A total of 106 hemodialysis patients were included. Each patient received two dialysis sessions in which only the monitor was varied. The variables collected were: concentrate, prescribed sodium and bicarbonate, real conductivity, initial and final plasma sodium measured by ionic dialysance, and the change in plasma sodium concentration during treatment (ΔPNa), which has been related to mortality when it exceeds 4 mmol/L, was calculated. The clinical research ethics committee of Hospital Clínic de Barcelona approved the present study. Results The change of dialysis monitor showed small, although significant, differences in initial (138.14 mmol/L with 5008 vs. 138.81 mmol/L with 6008) and final plasma sodium (139.58 mmol/L vs. 140.97 mmol/L), as well as in the actual conductivity obtained (13.97 vs. 14.1 mS/cm). The ΔPNa also increased significantly, with the percentage of patients with a ΔPNa greater than 4 mmol/L going from 6 to 22% with the monitor change. All these differences were statistically significant regardless of the concentrate used. All sessions were performed without notable clinical incidents, hypotension, cramps or thirst episodes. Conclusion The ultimate goal of hemodialysis should be to achieve isonatremia that allows complete elimination of interdialytic sodium gain and avoid intradialytic sodium loading. The change from 5008 to 6008 monitor is associated with an increase in conductivity, higher plasma sodium, and an increase in ΔPNa. Knowing and confirming this change will allow us to individualize the sodium prescription to find adequate isonatremic dialysis and, thus, avoid possible adverse effects.