Randomized Trial on the Effects of Dialysate Potassium Concentration on Intradialytic Hypertension

Introduction

Intradialytic hypertension is not an uncommon condition during chronic hemodialysis. It is associated with unfavorable cardiovascular outcomes, including hospitalization and mortality. Several small studies have demonstrated the contradictory effects of different dialysate potassium concentrations on intradialytic blood pressure. This study is a randomized crossover trial aiming to evaluate the effects of different dialysate potassium concentrations on intradialytic hypertension.

Methods

A 24-week, 2-treatment, 4-sequence, multicenter, double-blinded, randomized, crossover study was conducted at Maharaj Nakorn Chiang Mai Hospital and Lampang Hospital in Thailand among stable patients receiving chronic hemodialysis who experienced intradialytic hypertension >30% of their sessions over the past 3 months. Each participant was randomly assigned to 1 of 4 treatment sequences. During each intervention period, patients were dialyzed with dialysate potassium of either 2 mmol/l (D-K2) or 3 mmol/l (D-K3) for 4 weeks according to their preassigned sequence, separated by a 2-week washout period. The primary outcome was the incidence of intradialytic hypertension.

Results

Forty eligible patients were recruited. The mean age was 61.4 ± 14.2 years and the mean systolic blood pressure (SBP) was 146.6 ± 11.2 mm Hg. Of the 40 patients, 95.5% had hypertension and their average number of antihypertensive drugs was 2.8 ± 1.9. A total of 1380 dialysis sessions were included in the analysis (695 sessions for D-K2 and 685 sessions for D-K3). The incidence of intradialytic hypertension was not significantly different between different dialysate potassium concentrations (D-K2 54.7% vs. D-K3 53.1%, P = 0.788). The changes in SBP, diastolic blood pressure (DBP), and mean arterial pressure (MAP) were not different between the 2 dialysate potassium groups.

Conclusion

Dialysate potassium concentration of 2 or 3 mmol/l did not affect the incidence of intradialytic hypertension in patients receiving chronic hemodialysis who frequently developed intradialytic hypertension.