Treatment of severe intradialytic hypotension with the addition of high dialysate calcium concentration to midodrine and/or cool dialysate

Treatment of intradialytic hypotension (IDH) in the end-stage renal disease population has been a difficult task for nephrologists caring for these pa tients. The presence of multiple pathogenic factors contributes to hemodyna mic instability and explains why therapies that modulate only a specific as pect of the problem are only partially effective. Cool dialysate (34.5 degr eesC to 35.5 degreesC) and midodrine may provide hemodynamic stability thro ugh an increase in peripheral vascular resistance, whereas high dialysate c alcium concentration (HDCa; 3.5 mEq/L) improves intradialytic blood pressur e through preservation of cardiac output. Theoretically, the combination of these two types of therapies might further reduce the frequency and severi ty of hypotension during hemodialysis (HD). We undertook a study to evaluat e the effect of HDCa added to midodrine and/or cool dialysate in the treatm ent of patients with severe IDH. Twenty-eight patients met the entry criter ia, and 23 patients completed the prospective crossover study. Five patient s dropped out of the study secondary to hypercalcemia. The addition of HDCa significantly improved post-HD mean arterial pressure (MAP; 95.6 +/- 12.7 versus 90.8 +/- 12.5 mm Hg; P = 0.002). The decreases in MAP from pre-HD to lowest intradialytic (16.3 +/- 8.2 versus 20.6 +/- 10.0 mm Hg; P = 0.009) and pre-HD to post-HD (2.0 +/- 8.5 versus 8.15 +/- 10.8 mm Hg; P = 0.002) w ere significantly reduced with HDCa compared with low dialysate calcium. Ho wever, there were no significant improvements in symptoms of or interventio ns for IDH. Thus, it appears that the addition of HDCa to midodrine and/or cool dialysate further improves blood pressure in patients with IDH. Howeve r, this therapy did not reduce symptoms or interventions required for IDH. In addition, hypercalcemia complicated this therapy in 22% of the patients. (C) 2001 by the National Kidney Foundation, Inc.