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 patients. The presence of multiple pathogenic factors contributes to hemodynamic instability and explains why therapies that modulate only a specific aspect of the problem are only partially effective. Cool dialysate (34.5 degrees C to 35.5 degrees C) and midodrine may provide hemodynamic stability through an increase in peripheral vascular resistance, whereas high dialysate calcium concentration (HDCa; 3.5 mEq/L) improves intradialytic blood pressure through preservation of cardiac output. Theoretically, the combination of these two types of therapies might further reduce the frequency and severity of hypotension during hemodialysis (HD). We undertook a study to evaluate the effect of HDCa added to midodrine and/or cool dialysate in the treatment of patients with severe IDH. Twenty-eight patients met the entry criteria, and 23 patients completed the prospective crossover study. Five patients 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) were significantly reduced with HDCa compared with low dialysate calcium. However, there were no significant improvements in symptoms of or interventions for IDH. Thus, it appears that the addition of HDCa to midodrine and/or cool dialysate further improves blood pressure in patients with IDH. However, this therapy did not reduce symptoms or interventions required for IDH. In addition, hypercalcemia complicated this therapy in 22% of the patients.