Table 6.

Unadjusted and adjusted changes in prehemodialysis to posthemodialysis serum electrolytes according to different dialysate prescriptions

Dialysate PrescriptionChange in Serum Electrolyte (Posthemodialysis Minus Prehemodialysis) in mEq/L or mg/dl,a Mean (SEM)
Unadjustedb P ValueModel 1b P ValueModel 2b P Value
Dialysate sodium n/N (%)
 135 (mEq/L)−0.6 (0.6)−1.4 (0.5)−1.5 (0.5)
 191/1511 (13%)
 138 (mEq/L)−0.7 (1.2)−0.4 (0.9)−0.4 (0.9)
 146/1511 (10%)
 140 (mEq/L)0.5 (0.4)0.6 (0.3)0.6 (0.3)
 1174/1511 (78%)
0.10<0.001<0.001
Dialysate potassium
 1 and 2 (mEq/L)−1.3 (0.1)−1.3 (0.04)−1.3 (0.04)
 1336/1630 (82%)
 3 and 4 (mEq/L)−0.9 (0.1)−0.9 (0.1)−0.9 (0.1)
 294/1630 (18%)
<0.001<0.001<0.001
Dialysate bicarbonate
 24–32 (mEq/L)4.5 (0.5)3.7 (0.4)3.5 (0.5)
 351/1610 (22%)
 33–36 (mEq/L)4.8 (0.3)4.4 (0.3)4.5 (0.3)
 803/1610 (50%)
 37–40 (mEq/L)5.1 (0.4)6.7 (0.4)6.7 (0.4)
 456/1610 (28%)
0.57<0.001<0.001
Dialysate calcium
 1.5 and 1.6 (mEq/L)1.2 (0.2)0.8 (0.2)0.8 (0.2)
 359/1647 (22%)
 2 and 2.5 (mEq/L)0.4 (0.1)0.4 (0.1)0.4 (0.1)
 926/1647 (22%)
 3.0 and 3.5 (mEq/L)1.1 (0.1)1.4 (0.1)1.4 (0.1)
 362/1647 (22%)
<0.001<0.001<0.001
  • Model 1 adjusted for the pre-dialysis serum concentration; Model 2 adjusted for the predialysis serum concentration and dialysis session length.

  • Changes in serum sodium, potassium and bicarbonate are presented in mEq/L; changes in serum calcium are presented in mg/dl. P values for the association between categorical dialysate prescription with electrolyte change.

  • a Variability in number of sessions may be due to missing collections or data recording.

  • b Negative sign (−) indicates a decrease.