Effects of low sodium dialysate in chronic hemodialysis patients: an echocardiographic study

Chronic kidney disease (CKD) and hemodialysis (HD) patients who cannot restrict sodium consumption in their diets sometimes develop significant saline excess and hypertension between dialyses. This study assessed the effect of relatively low sodium dialysate dialysis on changes of echocardiography in hemodialysis patients.

Eighteen patients with end stage renal failure on chronic HD were studied (8 females, 10 males) with a mean age 48.3 +/- 14.6 (24-70) years. The mean time on HD was 30.8 +/- 14.0 (12-60) months. Patients with hematocrit levels under 24% were excluded from the study. In all patients, echocardiography was performed thrice weekly before and after eight-week HD treatment with low sodium dialysate hemodialysis by the same operator (135 mEq/L for patients with sodium levels less than 137, 137 for patients with sodium levels over 137). Left atrium (LA) and left ventricle (LV) volumes and ejection fractions were measured, specifically: LV systolic diameter (LVSD), LV diastolic diameter (LVDD), interventricular septum (IVS), tricuspid regurgitation (TR), mitral regurgitation (MR), pulmonary artery pressure (PAP), and inferior vein cava diameter (IVCD).

In terms of echocardiographic parameters, LVSD, TR, PAP, and IVCD were statistically decreased after low-sodium dialysate treatments (p = 0.002, 0.04, 0.013, and 0.00, respectively). Predialysis systolic and diastolic blood pressure (BP), post-dialysis systolic blood pressure, and interdialytic weight gain was statistically decreased when compared to basal levels (p = 0.00, p = 0.011, p = 0.022, p = 0.001, respectively).

A reduction of the dialysate sodium concentration based on the predialysis sodium levels of the patients could reduce the systolic BP and decrease the volume load on the heart as assessed by echocardiography. Within this short period, postdialysis diastolic BP could not be lowered. The effect of this approach should be studied in broad and lengthy series.