Individualized dialysate sodium prescriptions using sodium gradients for high-risk hemodialysis patients lowered interdialytic weight gain and achieved target weights

Abstract

Introduction: Large interdialytic weight gain (IDWG) is associated with increased morbidity and mortality in chronic hemodialysis patients. Over 50% of patients at our inner city tertiary academic center dialysis unit had IDWG and target weights (TW) above goal. We conducted an open-label nonrandomized study to explore the effects of an individualized dialysate sodium (DNa) prescription using Na gradients in patients at high risk for large IDWG. Thirty-three patients receiving chronic hemodialysis received individualized DNa prescriptions with a DNa bath of 0 to -2 meq/L below their serum Na level in the intervention group, while patients in the control group were prescribed the standard dialysate Na at 138 mmol/L. Serum Na level, predialysis SBP, symptomatic hypotensive episodes, and %hemodialysis treatments with large IDWG (%TxAIDWG) and above TW(%TxATW) were recorded before and three months after the intervention. We used student t tests to compare continuous variables and Chi-square tests to compare binary variables between the groups at baseline and after the intervention. Age- and sex-adjusted linear regression models were also constructed to assess the differences in each continuous outcome between the groups. Multivariable logistic regression models were conducted by modeling IDWG decrease and above estimated-dry-weight (EDW) decrease as binary dependent variables with adjustment for age, sex, and EDW change.

Findings: Patients with individualized DNa concentrations had 3.6 times greater odds of having lower IDWG than those with standard dialysate Na concentration. This significant association remained after adjustment for age, sex, and changes in EDW (OR: 3.63; 95% CI, 1.03-12.9). There was no difference in predialysis BP or symptomatic hypotensive episodes between the two groups.

Discussion: Individualized DNa prescriptions appeared to be well tolerated and may be effective for optimal fluid management in high-risk hemodialysis patients.

Keywords: Individualized dialysate sodium; above target weight; fluid overload; interdialytic weight gain.