Table 2.
Plasma Sodium Concentration and Outcomes in Each Study Phase
| Phase A (n = 15) | Phase B (n = 15) | Phase A+ (n = 14) | Pa | |
|---|---|---|---|---|
| Dialysate [Na] (mEq/L) | 140b | 134c or 136 | 140 | |
| [Na] gradient (mEq/L) | 4.2 ± 3.2 | −0.6 ± 1.5 | 2.9 ± 2.6 | |
| Dry weight (kg) | 86.8 ± 21.3 | 87.9 ± 21.6 | 87.2 ± 22.2 | |
| Pre-HD [Na] (mEq/L) | 136.2 ± 3.1 | 136.2 ± 2.1 | 137.1 ± 2.6d | 0.01 |
| Post-HD [Na] (mEq/L) | 142.1 ± 1.5 | 138.4 ± 1.5e | 141.1 ± 1.5 | −0.001 |
| IDWG (kg) | 4.2 ± 0.8 | 3.6 ± 0.6e | 4.1 ± 0.9 | 0.02 |
| IDWG% | 5.0 ± 1.0 | 4.4 ± 1.2e | 5.0 ± 1.8 | 0.03 |
| Pre-HD blood pressure | ||||
| Systolic (mm Hg) | 159.0 ± 22.0 | 150.7 ± 24.7e | 150.3 ± 30.2d | 0.03 |
| Diastolic (mm Hg) | 89.7 ± 11.6 | 84.0 ± 10.6 | 85.1 ± 15.4 | 0.1 |
| MAP (mm Hg) | 112.8 ± 13.3 | 106.2 ± 14.0 | 106.8 ± 19.8 | 0.07 |
| Post-HD blood pressure | ||||
| Systolic (mm Hg) | 128.6 ± 15.7 | 126.1 ± 14.6 | 132.5 ± 18.5 | 0.5 |
| Diastolic (mm Hg) | 77.6 ± 11.0 | 74.3 ± 11.0 | 80.9 ± 9.1 | 0.2 |
| MAP (mm Hg) | 94.6 ± 11.6 | 91.6 ± 11.2 | 98.0 ± 11.2 | 0.3 |
Note: Measurements are expressed as mean ± standard deviation.
Abbreviations and definitions: HD, hemodialysis; IDWG, interdialytic weight gain; IDWG%, IDWG divided by estimated dry weight, then multiplied by 100; MAP, mean arterial pressure; [Na], sodium concentration; [Na] gradient, dialysate sodium concentration minus the pre-HD plasma sodium concentration.
a
P values represent comparison among the 3 study phases.
b
One participant dialyzed in phase A with dialysate sodium concentration of 145 mEq/L.
c
Three participants dialyzed in phase B with dialysate sodium concentrations of 134 mEq/L.
d
P < 0.05 comparing phase A+ versus phase A.
e
P < 0.05 comparing phase B versus phase A.