Effect of Low-Sodium versus Conventional Sodium Dialysate on Left Ventricular Mass in Home and Self-Care Satellite Facility Hemodialysis Patients: A Randomized Clinical Trial.

BACKGROUND: Fluid overload in patients undergoing hemodialysis contributes to cardiovascular morbidity and mortality. There is a global trend to lower dialysate sodium with the goal of reducing fluid overload. METHODS: To investigate whether lower dialysate sodium during hemodialysis reduces left ventricular mass, we conducted a randomized trial in which patients received either low-sodium dialysate (135 mM) or conventional dialysate (140 mM) for 12 months. We included participants who were aged >18 years old, had a predialysis serum sodium ≥135 mM, and were receiving hemodialysis at home or a self-care satellite facility. Exclusion criteria included hemodialysis frequency >3.5 times per week and use of sodium profiling or hemodiafiltration. The main outcome was left ventricular mass index by cardiac magnetic resonance imaging. RESULTS: The 99 participants had a median age of 51 years old; 67 were men, 31 had diabetes mellitus, and 59 had left ventricular hypertrophy. Over 12 months of follow-up, relative to control, a dialysate sodium concentration of 135 mmol/L did not change the left ventricular mass index, despite significant reductions at 6 and 12 months in interdialytic weight gain, in extracellular fluid volume, and in plasma B-type natriuretic peptide concentration (ratio of intervention to control). The intervention increased intradialytic hypotension (odds ratio [OR], 7.5; 95% confidence interval [95% CI], 1.1 to 49.8 at 6 months and OR, 3.6; 95% CI, 0.5 to 28.8 at 12 months). Five participants in the intervention arm could not complete the trial because of hypotension. We found no effect on health-related quality of life measures, perceived thirst or xerostomia, or dietary sodium intake. CONCLUSIONS: Dialysate sodium of 135 mmol/L did not reduce left ventricular mass relative to control, despite improving fluid status. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: The Australian New Zealand Clinical Trials Registry, ACTRN12611000975998.

Low dialysate sodium levels for chronic haemodialysis.

BACKGROUND: Cardiovascular (CV) disease is the leading cause of death in dialysis patients, and strongly associated with fluid overload and hypertension. It is plausible that low dialysate [Na+] may decrease total body sodium content, thereby reducing fluid overload and hypertension, and ultimately reducing CV morbidity and mortality. OBJECTIVES: This review evaluated harms and benefits of using a low (< 138 mM) dialysate [Na+] for maintenance haemodialysis (HD) patients. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 7 August 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: Randomised controlled trials (RCTs), both parallel and cross-over, of low (< 138 mM) versus neutral (138 to 140 mM) or high (> 140 mM) dialysate [Na+] for maintenance HD patients were included. DATA COLLECTION AND ANALYSIS: Two investigators independently screened studies for inclusion and extracted data. Statistical analyses were performed using random effects models, and results expressed as risk ratios (RR) for dichotomous outcomes, and mean differences (MD) or standardised MD (SMD) for continuous outcomes, with 95% confidence intervals (CI). Confidence in the evidence was assessed using GRADE. MAIN RESULTS: We included 12 studies randomising 310 patients, with data available for 266 patients after dropout. All but one study evaluated a fixed concentration of low dialysate [Na+], and one profiled dialysate [Na+]. Three studies were parallel group, and the remaining nine cross-over. Of the latter, only two used a washout between intervention and control periods. Most studies were short-term with a median (interquartile range) follow-up of 3 (3, 8.5) weeks. Two were of a single HD session, and two of a single week's HD. Half of the studies were conducted prior to 2000, and five reported use of obsolete HD practices. Risks of bias in the included studies were often high or unclear, lowering confidence in the results.Compared to neutral or high dialysate [Na+], low dialysate [Na+] had the following effects on "efficacy" endpoints: reduced interdialytic weight gain (10 studies: MD -0.35 kg, 95% CI -0.18 to -0.51; high certainty evidence); probably reduced predialysis mean arterial blood pressure (BP) (4 studies: MD -3.58 mmHg, 95% CI -5.46 to -1.69; moderate certainty evidence); probably reduced postdialysis mean arterial BP (MAP) (4 studies: MD -3.26 mmHg, 95% CI -1.70 to -4.82; moderate certainty evidence); probably reduced predialysis serum [Na+] (7 studies: MD -1.69 mM, 95% CI -2.36 to -1.02; moderate certainty evidence); may have reduced antihypertensive medication (2 studies: SMD -0.67 SD, 95% CI -1.07 to -0.28; low certainty evidence). Compared to neutral or high dialysate [Na+], low dialysate [Na+] had the following effects on "safety" endpoints: probably increased intradialytic hypotension events (9 studies: RR 1.56, 95% 1.17 to 2.07; moderate certainty evidence); probably increased intradialytic cramps (6 studies: RR 1.77, 95% 1.15 to 2.73; moderate certainty evidence).Compared to neutral or high dialysate [Na+], low dialysate [Na+] may make little or no difference to: intradialytic BP (2 studies: MD for systolic BP -3.99 mmHg, 95% CI -17.96 to 9.99; diastolic BP 1.33 mmHg, 95% CI -6.29 to 8.95; low certainty evidence); interdialytic BP (2 studies:, MD for systolic BP 0.17 mmHg, 95% CI -5.42 to 5.08; diastolic BP -2.00 mmHg, 95% CI -4.84 to 0.84; low certainty evidence); dietary salt intake (2 studies: MD -0.21g/d, 95% CI -0.48 to 0.06; low certainty evidence).Due to very low quality of evidence, it is uncertain whether low dialysate [Na+] changed extracellular fluid status, venous tone, arterial vascular resistance, left ventricular mass or volumes, thirst or fatigue. Studies did not examine cardiovascular or all-cause mortality, cardiovascular events, or hospitalisation. AUTHORS' CONCLUSIONS: It is likely that low dialysate [Na+] reduces intradialytic weight gain and BP, which are effects directionally associated with improved outcomes. However, the intervention probably also increases intradialytic hypotension and reduces serum [Na+], effects that are associated with increased mortality risk. The effect of the intervention on overall patient health and well-being is unknown. Further evidence is needed in the form of longer-term studies in contemporary settings, evaluating end-organ effects in small-scale mechanistic studies using optimal methods, and clinical outcomes in large-scale multicentre RCTs.

Independent community house hemodialysis as a novel dialysis setting: an observational cohort study.

BACKGROUND: There is revived interest in home hemodialysis (HD), which is spurred by cost containment and experience indicating lower mortality risk compared with facility HD and peritoneal dialysis (PD). Social barriers to home HD include disruptions to the home environment, interference with family life, overburdening of support networks, and fear of social isolation. A submodality of home HD, in which patients from urban settings undertake independent HD in unstaffed nonmedical community-based home-like settings, is described in this study. The survival of patients treated in this manner is compared with that of those using conventional home HD. STUDY DESIGN: An observational cohort study using the Australia and New Zealand Dialysis and Transplant Registry. SETTING & PARTICIPANTS: All adult patients starting renal replacement therapy in New Zealand since March 31, 2000, followed up through December 31, 2010. PREDICTOR: The main predictor was time-varying dialysis modality (home HD, facility HD, PD, and community house HD), adjusting for the confounding effects of patient demographics and time-varying comorbid conditions. OUTCOME: Patient mortality. RESULTS: 4,709 patients with 12,883 patient-years of follow-up (5,591, PD; 1,532, home HD; 5,647, facility HD; and 113, community house HD) were analyzed. Community house HD patients were younger, healthier, and more likely to be Pacific people than those using other modalities, including home HD. Relative to home HD, adjusted mortality HRs were 2.18 (95% CI, 1.78-2.67) for facility HD, 2.17 (95% CI, 1.77-2.66) for PD, and 1.48 (95% CI, 0.64-3.40) for community house HD. LIMITATIONS: Small number of patients receiving community house HD, possible residual confounding from the limited collection of comorbid conditions (eg, no collection of cognitive or motor impairment), and absence of socioeconomic, medication, and biochemical data in analyses. CONCLUSIONS: Within limits, this study shows community house HD to be both safe and effective. Community house HD provides an option to improve the uptake of home HD.

Are dialysate sodium levels too high?

Universal lower dialysate [Na+] is often advocated as a means of improving the dire cardiovascular plight of our dialysis patients. However, there is evidence associating lower dialysate [Na+] and increased morbidity and mortality especially in frailer patients, probably as a result of more frequent intra-dialytic hypotension. In this editorial, we summarize arguments for and against lower dialysate [Na+], and provide recommendations around selecting the most appropriate dialysate [Na+] for specific clinical subsets that may benefit from manipulation of salt and water balance. The lack of overall clarity on relative benefits and risks of lower dialysate [Na+] does not support the case for empirical "across the board" change, and experimental testing in clinical trials is required to determine safe and effective use.