Effect of Dialysate and Plasma Sodium on Mortality in a Global Historical Hemodialysis Cohort.

SIGNIFICANCE STATEMENT: This large observational cohort study aimed to investigate the relationship between dialysate and plasma sodium concentrations and mortality among maintenance hemodialysis patients. Using a large multinational cohort of 68,196 patients, we found that lower dialysate sodium concentrations (≤138 mmol/L) were independently associated with higher mortality compared with higher dialysate sodium concentrations (>138 mmol/L). The risk of death was lower among patients exposed to higher dialysate sodium concentrations, regardless of plasma sodium levels. These results challenge the prevailing assumption that lower dialysate sodium concentrations improve outcomes in hemodialysis patients. The study confirms that until robust evidence from randomized trials that are underway is available, nephrologists should remain cautious in reconsideration of dialysate sodium prescribing practices to optimize cardiovascular outcomes and reduce mortality in this population. BACKGROUND: Excess mortality in hemodialysis (HD) patients is largely due to cardiovascular disease and is associated with abnormal fluid status and plasma sodium concentrations. Ultrafiltration facilitates the removal of fluid and sodium, whereas diffusive exchange of sodium plays a pivotal role in sodium removal and tonicity adjustment. Lower dialysate sodium may increase sodium removal at the expense of hypotonicity, reduced blood volume refilling, and intradialytic hypotension risk. Higher dialysate sodium preserves blood volume and hemodynamic stability but reduces sodium removal. In this retrospective cohort, we aimed to assess whether prescribing a dialysate sodium ≤138 mmol/L has an effect on survival outcomes compared with dialysate sodium >138 mmol/L after adjusting for plasma sodium concentration. METHODS: The study population included incident HD patients from 875 Fresenius Medical Care Nephrocare clinics in 25 countries between 2010 and 2019. Baseline dialysate sodium (≤138 or >138 mmol/L) and plasma sodium (<135, 135-142, >142 mmol/L) concentrations defined exposure status. We used multivariable Cox regression model stratified by country to model the association between time-varying dialysate and plasma sodium exposure and all-cause mortality, adjusted for demographic and treatment variables, including bioimpedance measures of fluid status. RESULTS: In 2,123,957 patient-months from 68,196 incident HD patients with on average three HD sessions per week dialysate sodium of 138 mmol/L was prescribed in 63.2%, 139 mmol/L in 15.8%, 140 mmol/L in 20.7%, and other concentrations in 0.4% of patients. Most clinical centers (78.6%) used a standardized concentration. During a median follow-up of 40 months, one third of patients ( n =21,644) died. Dialysate sodium ≤138 mmol/L was associated with higher mortality (multivariate hazard ratio for the total population (1.57, 95% confidence interval, 1.25 to 1.98), adjusted for plasma sodium concentrations and other confounding variables. Subgroup analysis did not show any evidence of effect modification by plasma sodium concentrations or other patient-specific variables. CONCLUSIONS: These observational findings stress the need for randomized evidence to reliably define optimal standard dialysate sodium prescribing practices.

[Renal insufficiency and cardiovascular risk]. / Niereninsuffizienz und kardiovaskuläres Risiko.

Patients with chronic renal insufficiency often show symptoms that are atypical for cardiovascular problems. The correct interpretation of the symptoms is crucial in order to correctly assess the risk of a heart-related emergency and to take preventive measures and initiate the right therapy. Biomarkers such as NT-proBNP, troponin T or hsCRP (highly sensitive CRP) are independent predictors of mortality, but do not replace instrument-based diagnostics. Patients with renal insufficiency often have stiff vessels which, due to the premature reflection of the pulse wave, can lead to left ventricular dysfunction and ultimately to heart failure.

Hyponatraemia and fluid overload are associated with higher risk of mortality in dialysis patients.

BACKGROUND: The 5-year mortality rate for haemodialysis patients is over 50%. Acute and chronic disturbances in salt and fluid homeostasis contribute to poor survival and are established as individual mortality risk factors. However, their interaction in relation to mortality is unclear. METHODS: We used the European Clinical Database 5 to investigate in a retrospective cohort analysis the relationship between transient hypo- and hypernatremia, fluid status and mortality risk of 72 163 haemodialysis patients from 25 countries. Incident haemodialysis patients with at least one valid measurement of bioimpedance spectroscopy were followed until death or administrative censoring from 1 January 2010 to 4 December 2019. Fluid overload and depletion were defined as >2.5 L above, and -1.1 L below normal fluid status, respectively. N = 2 272 041 recorded plasma sodium and fluid status measurements were available over a monthly time grid and analysed in a Cox regression model for time-to-death. RESULTS: Mortality risk of hyponatremia (plasma sodium <135 mmol/L) was slightly increased when fluid status was normal [hazard ratio (HR) 1.26, 95% confidence interval (CI) 1.18-1.35], increased by half when patients were fluid depleted (HR 1.56, 95% CI 1.27-1.93) and accelerated during fluid overload (HR 1.97, 95% CI 1.82-2.12). CONCLUSIONS: Plasma sodium and fluid status act independently as risk factors on mortality. Patient surveillance of fluid status is especially important in the high-risk subpopulation of patients with hyponatremia. Prospective patient-level studies should examine the effects of chronic hypo- and hypernatremia, risk determinants, and their outcome risk.

Relationship between measured and prescribed dialysate sodium in haemodialysis: a systematic review and meta-analysis.

BACKGROUND: Dialysate sodium (DNa) prescription policy differs between haemodialysis (HD) units, and the optimal DNa remains uncertain. We sought to summarize the evidence on the agreement between prescribed and delivered DNa, and whether the relationship varied according to prescribed DNa. METHODS: We searched MEDLINE and PubMed from inception to 26 February 2020 for studies reporting measured and prescribed DNa. We analysed results reported in aggregate with random-effects meta-analysis. We analysed results reported by individual sample, using mixed-effects Bland-Altman analysis and linear regression. Pre-specified subgroup analyses included method of sodium measurement, dialysis machine manufacturer and proportioning method. RESULTS: Seven studies, representing 908 dialysate samples from 10 HD facilities (range 16-133 samples), were identified. All but one were single-centre studies. Studies were of low to moderate quality. Overall, there was no statistically significant difference between measured and prescribed DNa {mean difference = 0.73 mmol/L [95% confidence interval (CI) -1.12 to 2.58; P = 0.44]} but variability across studies was substantial (I2 = 99.3%). Among individually reported samples (n = 295), measured DNa was higher than prescribed DNa by 1.96 mmol/L (95% CI 0.23-3.69) and the 95% limits of agreement ranged from -3.97 to 7.88 mmol/L. Regression analysis confirmed a strong relationship between prescribed and measured DNa, with a slope close to 1:1 (ß = 1.16, 95% CI 1.06-1.27; P < 0.0001). CONCLUSIONS: A limited number of studies suggest that, on average, prescribed and measured DNa are similar. However, between- and within-study differences were large. Further consideration of the precision of delivered DNa is required to inform rational prescribing.

Sodium, volume and pressure control in haemodialysis patients for improved cardiovascular outcomes.

Chronic volume overload is pervasive in patients on chronic haemodialysis and substantially increases the risk of cardiovascular death. The rediscovery of the three-compartment model in sodium metabolism revolutionizes our understanding of sodium (patho-)physiology and is an effect modifier that still needs to be understood in the context of hypertension and end-stage kidney disease. Assessment of fluid overload in haemodialysis patients is central yet difficult to achieve, because traditional clinical signs of volume overload lack sensitivity and specificity. The highest all-cause mortality risk may be found in haemodialysis patients presenting with high fluid overload but low blood pressure before haemodialysis treatment. The second highest risk may be found in patients with both high blood pressure and fluid overload, while high blood pressure but normal fluid overload may only relate to moderate risk. Optimization of fluid overload in haemodialysis patients should be guided by combining the traditional clinical evaluation with objective measurements such as bioimpedance spectroscopy in assessing the risk of fluid overload. To overcome the tide of extracellular fluid, the concept of time-averaged fluid overload during the interdialytic period has been established and requires possible readjustment of a negative target post-dialysis weight. 23Na-magnetic resonance imaging studies will help to quantitate sodium accumulation and keep prescribed haemodialytic sodium mass balance on the radar. Cluster-randomization trials (e.g. on sodium removal) are underway to improve our therapeutic approach to cardioprotective haemodialysis management.

Identifying Outcomes that Are Important to Living Kidney Donors: A Nominal Group Technique Study.

BACKGROUND AND OBJECTIVES: Living kidney donor candidates accept a range of risks and benefits when they decide to proceed with nephrectomy. Informed consent around this decision assumes they receive reliable data about outcomes they regard as critical to their decision making. We identified the outcomes most important to living kidney donors and described the reasons for their choices. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Previous donors were purposively sampled from three transplant units in Australia (Sydney and Melbourne) and Canada (Vancouver). In focus groups using the nominal group technique, participants identified outcomes of donation, ranked them in order of importance, and discussed the reasons for their preferences. An importance score was calculated for each outcome. Qualitative data were analyzed thematically. RESULTS: Across 14 groups, 123 donors aged 27-78 years identified 35 outcomes. Across all participants, the ten highest ranked outcomes were kidney function (importance=0.40, scale 0-1), time to recovery (0.27), surgical complications (0.24), effect on family (0.22), donor-recipient relationship (0.21), life satisfaction (0.18), lifestyle restrictions (0.18), kidney failure (0.14), mortality (0.13), and acute pain/discomfort (0.12). Kidney function and kidney failure were more important to Canadian participants, compared with Australian donors. The themes identified included worthwhile sacrifice, insignificance of risks and harms, confidence and empowerment, unfulfilled expectations, and heightened susceptibility. CONCLUSIONS: Living kidney donors prioritized a range of outcomes, with the most important being kidney health and the surgical, lifestyle, functional, and psychosocial effects of donation. Donors also valued improvements to their family life and donor-recipient relationship. There were clear regional differences in the rankings.

Perspectives of Older Kidney Transplant Recipients on Kidney Transplantation.

BACKGROUND AND OBJECTIVES: Older kidney transplant recipients are susceptible to cognitive impairment, frailty, comorbidities, immunosuppression-related complications, and chronic graft failure, however, there has been limited focus on their concerns and expectations related to transplantation. This study aims to describe the perspectives of older kidney transplant recipients about their experience of kidney transplantation, self-management, and treatment goals to inform strategies and interventions that address their specific needs. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Face-to-face semistructured interviews were conducted with 30 kidney transplant recipients aged 65-80 years from five renal units in Australia. Transcripts were analyzed thematically. RESULTS: Six themes were identified: restoring vitality of youth (with subthemes of revived mindset for resilience, embracing enjoyment in life, drive for self-actualization); persisting through prolonged recovery (yielding to aging, accepting functional limitations, pushing the limit, enduring treatment responsibilities); imposing sicknesses (combatting devastating comorbidities, painful restrictions, emerging disillusionment, anxieties about accumulating side effects, consuming treatment burden); prioritizing graft survival (privileged with a miracle, negotiating risks for longevity, enacting a moral duty, preserving the last opportunity); confronting health deterioration (vulnerability and helplessness, narrowing focus to immediate concerns, uncertainty of survival); and value of existence (purpose through autonomy, refusing the burden of futile treatment, staying alive by all means). CONCLUSIONS: Older kidney transplant recipients felt able to enjoy life and strived to live at their newly re-established potential and capability, which motivated them to protect their graft. However, some felt constrained by slow recuperation and overwhelmed by unexpected comorbidities, medication-related side effects, and health decline. Our findings suggest the need to prepare and support older recipients for self-management responsibilities, clarify their expectations of post-transplant risks and outcomes, and provide assistance through prolonged recovery after kidney transplantation.

Identifying and integrating patient and caregiver perspectives for clinical practice guidelines on the screening and management of infectious microorganisms in hemodialysis units.

INTRODUCTION: The integration of patient and caregiver input into guideline development can help to ensure that clinical care addresses patient expectations, priorities, and needs. We aimed to identify topics and outcomes salient to patients and caregivers for inclusion in the Kidney Health Australia Caring for Australasians with Renal Impairment (KHA-CARI) clinical practice guideline on the screening and management of infectious microorganisms in hemodialysis units. METHODS: A facilitated workshop was conducted with 11 participants (patients [n = 8], caregivers [n = 3]). Participants identified and discussed potential topics for inclusion in the guidelines, which were compared to those developed by the guideline working group. The workshop transcript was thematically analyzed to identify and describe the reasons underpinning their priorities. FINDINGS: Patients and caregivers identified a range of topics already covered by the scope of the proposed guidelines and also suggested additional topics: privacy and confidentiality, psychosocial care during/after disease notification, quality of transportation, psychosocial treatment of patients in isolation, patient/caregiver education and engagement, and patient advocacy. Five themes characterized discussion and underpinned their choices: shock and vulnerability, burden of isolation, fear of infection, respect for privacy and confidentiality, and confusion over procedural inconsistencies. DISCUSSION: Patients and caregivers emphasized the need for guidelines to address patient education and engagement, and the psychosocial implications of communication and provision of care in the context of infectious microorganisms in hemodialysis units. Integrating patient and caregiver perspectives can help to improve the relevance of guidelines to enhance quality of care, patient experiences, and health and psychosocial outcomes.

Establishing Core Outcome Domains in Hemodialysis: Report of the Standardized Outcomes in Nephrology-Hemodialysis (SONG-HD) Consensus Workshop.

Evidence-informed decision making in clinical care and policy in nephrology is undermined by trials that selectively report a large number of heterogeneous outcomes, many of which are not patient centered. The Standardized Outcomes in Nephrology-Hemodialysis (SONG-HD) Initiative convened an international consensus workshop on November 7, 2015, to discuss the identification and implementation of a potential core outcome set for all trials in hemodialysis. The purpose of this article is to report qualitative analyses of the workshop discussions, describing the key aspects to consider when establishing core outcomes in trials involving patients on hemodialysis therapy. Key stakeholders including 8 patients/caregivers and 47 health professionals (nephrologists, policymakers, industry, and researchers) attended the workshop. Attendees suggested that identifying core outcomes required equitable stakeholder engagement to ensure relevance across patient populations, flexibility to consider evolving priorities over time, deconstruction of language and meaning for conceptual consistency and clarity, understanding of potential overlap and associations between outcomes, and an assessment of applicability to the range of interventions in hemodialysis. For implementation, they proposed that core outcomes must have simple, inexpensive, and validated outcome measures that could be used in clinical care (quality indicators) and trials (including pragmatic trials) and endorsement by regulatory agencies. Integrating these recommendations may foster acceptance and optimize the uptake and translation of core outcomes in hemodialysis, leading to more informative research, for better treatment and improved patient outcomes.

'I feel stronger and younger all the time'-perspectives of elderly kidney transplant recipients: thematic synthesis of qualitative research.

BACKGROUND: Kidney transplantation offers improved survival and quality of life to an increasing number of elderly patients with end-stage kidney disease. However, elderly kidney transplant recipients may face unique challenges due to a higher burden of comorbidity, greater cumulative risk of immunosuppression-related complications and increasing frailty. We aimed to describe the perspectives of elderly kidney transplant recipients. METHODS: Electronic databases were searched to April 2015. Qualitative studies were eligible if they reported views from elderly kidney transplant recipients (≥60 years). Thematic synthesis was used to analyse the findings. RESULTS: Twenty-one studies involving >116 recipients were included. We identified seven themes. 'Regaining strength and vitality' meant valuing the physical and psychosocial improvements in daily functioning and life participation. 'Extending life' was the willingness to accept any organ, including extended criteria kidneys, to prolong survival. 'Debt of gratitude' entailed conscious appreciation toward their donor while knowing they were unable to repay their sacrifice. 'Moral responsibility to maintain health' motivated adherence to medication and lifestyle recommendations out of an ethical duty to protect their gift for graft survival. 'Unabating and worsening forgetfulness' hindered self-management. 'Disillusionment with side effects and complications' reflected disappointment and exasperation with the unintended consequences of medications. 'Finality of treatment option' was an acute awareness that the current transplant may be their last. CONCLUSIONS: Kidney transplantation was perceived to slow and even reverse the experience of aging among elderly recipients, especially compared with dialysis. However, some were frustrated over persistent limitations after transplant, struggled with the burden of medication side effects and worried about a possible return to dialysis if the transplant failed. Clarifying patient expectations of transplantation, providing support to alleviate the debilitating impacts of immunosuppression and addressing fears about deteriorating health and graft failure may improve satisfaction and outcomes in elderly kidney transplant recipients.