P1243ABSOLUTE BLOOD VOLUME VARIATIONS INFLUENCED BY DIALYSATE TEMPERATURE DURING HAEMODIALYSIS

Abstract

Abstract Background and Aims Intradialytic hypotension is a common complication in haemodialysis. Vascular refilling occurs to preserve haemodynamic stability. Recent studies report a feasible and noninvasive method to determine absolute blood volume, which would allow us to estimate vascular refilling during haemodialysis. During years, it has been proposed that lowering the dialysate temperature could improve intradialytic hypotension outcomes in patients undergoing chronic haemodialysis. The objective of this study is to analyze if lowering dialysate temperature modifies variations in absolute blood volume during haemodialysis. Method The study was performed in 51 patients under haemodialysis treatment. During two different sessions, relative blood volume was assessed using dialysate temperatures of 35.5ºC (cool dialysate) and 36.5ºC (neutral dialysate). Absolute blood volume and vascular refilling were calculated using Kron et al methodology (Hemodial Int. 2016;20(3):484–91). Intradialytic hypotension was defined as a systolic blood pressure below 85 mmHg or a drop of pressure above 20 mmHg accompanied by symptoms. Statistical analysis was performed using paired t-Test or Wilcoxon rank sum. Results 31 episodes of intradialytic hypotension were observed, 14 under cool dialysate and 26 during neutral dialysate. We did not found statistically differences in absolute blood volume or in refilling volume between cool and warm dialysate temperature. In the group of patients with intradialytic hypotension (Table 1) we observed lower drop in absolute blood volume in the 35.5ºC dialysate group (0.59 L) versus 36.5ºC group (0.72 L). Although no statistically significant differences were found in vascular refilling volumes, when cool dialysate was used refilling tended to be higher. Conclusion It seems that in selected groups of patients the use of cool dialysate could improve absolute blood volume stability during HD treatments, although further studies are needed.