Table 6.

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

Dialysate Prescription	Change in Serum Electrolyte (Posthemodialysis Minus Prehemodialysis) in mEq/L or mg/dl,a Mean (SEM)
	Unadjustedb	P Value	Model 1b	P Value	Model 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.

^aVariability in number of sessions may be due to missing collections or data recording.

^bNegative sign (−) indicates a decrease.