Dialysis Prescription and Sudden Death

Racial Disparities in End-Stage Kidney Disease Outcomes among Asians and Native Hawaiians and Other Pacific Islanders across Geographic Residence

INTRODUCTION

While Asian and Native Hawaiian and other Pacific Islander (NHOPI) patients have a high prevalence of kidney disease risk factors, there are sparse data examining their end-stage kidney disease (ESKD) outcomes. As Hawaii has high representation of Asian and NHOPI individuals, we compared their ESKD outcomes based on residence in the mainland USA versus Hawaii/Pacific Islands (PIs).

MATERIALS AND METHODS

Using United States Renal Data System data, we examined the impact of geographic residence in the mainland versus Hawaii/PIs on race-mortality associations among incident ESKD patients transitioning to dialysis over January 1, 2000-December 31, 2016 using Cox regression. We examined likelihood of post-dialysis kidney transplantation using Cox models and cumulative incidence curves.

RESULTS

Compared with White patients in the mainland, Asian and NHOPI patients in the mainland had lower mortality: adjusted HRs (95% CIs) 0.67 (0.66-0.67) and 0.72 (0.70-0.73), respectively. When examining Asian and NHOPI patients in Hawaii/PIs, survival benefit was attenuated in Asian and diminished to the null in NHOPI patients (ref: mainland White patients). Cumulative incidence curves comparing Asian, NHOPI, and White patients showed Asian and NHOPI patients in the mainland had the highest likelihood of transplantation, whereas NHOPI and Asian patients in Hawaii/PIs had the lowest likelihood.

CONCLUSION

In the mainland, Asian and NHOPI patients had lower mortality versus White patients, whereas in Hawaii/PIs, this survival benefit was diminished in Asian and mitigated in NHOPI patients. NHOPI and Asian patients in Hawaii/PIs had less transplantation versus those in the mainland. Further research is needed to uncover factors contributing to differential ESKD outcomes among Asian and NHOPI patients across geographic residence.

Optical monitoring of hemodialysis using noninvasive measurement of uric acid in the dialysate

The aim of this study was to present a methodology for predicting changes in uric acid concentrations in the blood of chronically hemodialyzed patients based on an optical measurement of the intensity of selected wavelengths in the dialysate. Blood samples were taken from the arterial line every 30 min throughout the hemodialysis period, to measure uric acid levels. Simultaneously, optical measurements were made on dialysate flowing from the dialyzer. Uric acid concentration can be measured either directly from the blood or from dialyzer outflow with acceptable error. In addition, both methods reveal any increased dynamics in uric acid concentration in the initial phase of hemodialysis. The wavelength of the light was adjusted for optimal uric acid particle detection. Comparing the uric acid concentration measured in the blood of patients with the intensity of wave absorption in the dialysate, the functional relationship between the uric acid concentration levels was determined. Using the optical method for measuring uric acid concentration in the dialysate, the concentration of uric acid in the blood during hemodialysis can be non-invasively and accurately estimated. This method can be used to assess the adequacy of hemodialysis by computer acquisition of uric acid concentrations determined in on-line dialysate.

Epidemiological analysis of death among patients on maintenance hemodialysis: results from the beijing blood purification quality Control and Improvement Center

BACKGROUND

China has the largest number of patients on maintenance hemodialysis (MHD) worldwide. Despite continuous improvements in hemodialysis techniques, patients on MHD have a higher mortality rate than the general population. Understanding the characteristics of death in this population can better promote clinical practice, thereby improving patients' survival.

METHODS

We collected demographic and clinical data for patients on MHD registered in the Beijing Blood Purification Quality Control and Improvement Center database from 2014 to 2020. The annual mortality rate was calculatedand the primary cause of end-stage renal disease (ESRD), dialysis vintage, and cause of death among deceased patients were analyzed.

RESULTS

(1) 24,363 patients on MHD were included, of which 6,065 patients died from 2014 to 2020. The annual mortality rate fluctuated between 7.4% and 8.0%. The median age of death was 70.0 (60.8-79.0) years and the male to female ratio was 1.27:1 (2). The top three primary causes of ESRD in deceased patients were chronic glomerulonephritis (CGN), diabetic nephropathy (DN), and hypertensive nephropathy (HN). Comparison of the annual mortality rate showed DN > HN > CGN (3). The median dialysis vintage of deceased patients was 3.7 (1.8-6.9) years, which slowly increased annually. Patients with diabetes had a shorter dialysis vintage than patients without diabetes (3.4 vs. 4.1 years, Z = 8.3, P < 0.001) (4). The major causes of death were cardiovascular disease (20.2%), sudden death (18.1%), infection (17.9%), and cerebrovascular disease (12.6%). Proportions of death from cardiovascular disease, infection, and sudden death were higher in patients with diabetes (22.2%, 20.2%, and 20.0%) than patients without diabetes (18.4%, 15.8%, and 16.3%). Sudden death was the leading cause of death in young (18-44 years; 27.0%) and middle aged (45-64 years; 20.8%) patients, whereas infection was the leading cause of death in patients aged ≥ 75 years (24.5%).

CONCLUSION

The annual mortality rate of patients on MHD in Beijing was relatively stable from 2014 to 2020. Sudden death was more likely to occur in young and middle-aged patients, and more patients aged ≥ 75 years died from infections.

Cause-Specific Mortality in Patients With Advanced Chronic Kidney Disease in the ISCHEMIA-CKD Trial

BACKGROUND

In ISCHEMIA-CKD, 777 patients with advanced chronic kidney disease and chronic coronary disease had similar all-cause mortality with either an initial invasive or conservative strategy (27.2% vs 27.8%, respectively).

OBJECTIVES

This prespecified secondary analysis from ISCHEMIA-CKD (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches-Chronic Kidney Disease) was conducted to determine whether an initial invasive strategy compared with a conservative strategy decreased the incidence of cardiovascular (CV) vs non-CV causes of death.

METHODS

Three-year cumulative incidences were calculated for the adjudicated cause of death. Overall and cause-specific death by treatment strategy were analyzed using Cox models adjusted for baseline covariates. The association between cause of death, risk factors, and treatment strategy were identified.

RESULTS

A total of 192 of the 777 participants died during follow-up, including 94 (12.1%) of a CV cause, 59 (7.6%) of a non-CV cause, and 39 (5.0%) of an undetermined cause. The 3-year cumulative rates of CV death were similar between the invasive and conservative strategies (14.6% vs 12.6%, respectively; HR: 1.13, 95% CI: 0.75-1.70). Non-CV death rates were also similar between the invasive and conservative arms (8.4% and 8.2%, respectively; HR: 1.25; 95% CI: 0.75-2.09). Sudden cardiac death (46.8% of CV deaths) and infection (54.2% of non-CV deaths) were the most common cause-specific deaths and did not vary by treatment strategy.

CONCLUSIONS

In ISCHEMIA-CKD, CV death was more common than non-CV or undetermined death during the 3-year follow-up. The randomized treatment assignment did not affect the cause-specific incidences of death in participants with advanced CKD and moderate or severe myocardial ischemia. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches-Chronic Kidney Disease [ISCHEMIA-CKD]; NCT01985360).

Mortality and Quality of Life with Chronic Kidney Disease: A Five-Year Cohort Study with a Sample Initially Receiving Peritoneal Dialysis

The quality of life, morbidity and mortality of people receiving renal replacement therapy is affected both by the renal disease itself and its treatment. The therapy that best improves renal function and quality of life is transplantation. Objectives: To study the quality of life, morbidity and mortality of people receiving renal replacement therapy over a five-year period. Design: A longitudinal multicentre study of a cohort of people with chronic kidney disease. Methods: Patients from the Girona health area receiving peritoneal dialysis were studied, gathering data on sociodemographic and clinical variables through an ad hoc questionnaire, quality of life using the SF-36 questionnaire, and social support with the MOS scale. Results: Mortality was 47.2%. Physical functioning was the variable that worsened most in comparison with the first measurement (p = 0.035). Those receiving peritoneal dialysis (p = 0.068) and transplant recipients (p = 0.083) had a better general health perception. The social functioning of transplant recipients improved (p = 0.008). Conclusions: People with chronic kidney disease had a high level of mortality. The dimension of physical functioning worsens over the years. Haemodialysis is the therapy that most negatively effects general health perception. Kidney transplantation has a positive effect on the dimensions of energy/vitality, social functioning and general health perception.

Direct arterial puncture for hemodialysis, a neglected but simple and valuable vascular access

Introduction

The purpose of this study is to present the prevalence and effects of direct arterial puncture (DAP) for hemodialysis patients, and to introduce optimal option for the vascular access (VA) in certain hemodialysis patients with poor condition of vascular or cardiac function in a compelling situation.

Methods

This was a cross-sectional study. Demographic characteristics and laboratory data were extracted from the health care system. Relevant DAP information was collected by a questionnaire. Case-control matching was performed to compare the hemodialysis adequacy between DAP and other VAs.

Results

A total of 526 patients were selected for analysis by convenience sampling, of which 38 patients relied https://www.baidu.com/link?url=eaDh8Hn-yZGJyDB0_h4zBenKd7qY1yX-KNxO-qU49gktQOGTJJg3slTjIbG095st4hRfprQIHRjfhfeGOZyH73y8tvSUCwMmvWbUhyix2ZKon DAP for hemodialysis. The main reasons using DAP for hemodialysis included the cost of arteriovenous access creation or maintenance in 19(50%) patients and the poor condition of vascular or cardiac function in 14 (39.5%) patients. Some complications of DAP occurred, such as aneurysm or pseudoaneurysm in 16(42.1%) patients, infiltration in 12 (31.6%) patients. Differences in hemodialysis adequacy were not statistically significant between DAP and other types of VA.

Conclusion

In conclusion, DAP can meet the need of prescription hemodialysis, yet it has several limitations. Although the patients in our study were long-term dependent on DAP for hemodialysis with various reasons, we do not recommend DAP as a long-term vascular access if better options are available. However, DAP should not be overlooked to be a supplemental VA for hemodialysis with adequate blood flow and availability for individuals with poor condition of vascular or cardiac function in a compelling situation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02836-1.

Hidden risks associated with conventional short intermittent hemodialysis: A call for action to mitigate cardiovascular risk and morbidity

The development of maintenance hemodialysis (HD) for end stage kidney disease patients is a success story that continues to save many lives. Nevertheless, intermittent renal replacement therapy is also a source of recurrent stress for patients. Conventional thrice weekly short HD is an imperfect treatment that only partially corrects uremic abnormalities, increases cardiovascular risk, and exacerbates disease burden. Altering cycles of fluid loading associated with cardiac stretching (interdialytic phase) and then fluid unloading (intradialytic phase) likely contribute to cardiac and vascular damage. This unphysiologic treatment profile combined with cyclic disturbances including osmotic and electrolytic shifts may contribute to morbidity in dialysis patients and augment the health burden of treatment. As such, HD patients are exposed to multiple stressors including cardiocirculatory, inflammatory, biologic, hypoxemic, and nutritional. This cascade of events can be termed the dialysis stress storm and sickness syndrome. Mitigating cardiovascular risk and morbidity associated with conventional intermittent HD appears to be a priority for improving patient experience and reducing disease burden. In this in-depth review, we summarize the hidden effects of intermittent HD therapy, and call for action to improve delivered HD and develop treatment schedules that are better tolerated and associated with fewer adverse effects.

Switching from high-flux dialysis to hemodiafiltration: Cost-consequences for patients, providers, and payers

Hemodiafiltration (HDF) achieves a more efficient reduction of the uremic toxic load compared to standard high-flux hemodialysis (HF-HD) by virtue of the combined diffusive and convective clearances of a broad spectrum of uremic retention solutes. Clinical trials and registry data suggest that HDF improves patient outcomes. Despite the acknowledged need to improve survival rates of dialysis patients and the survival benefit HDF offers, there is little to no utilization in some countries (such as the US) in prescribing HDF to their patients. In this analysis, we present the healthcare value-based case for HDF (relative to HF-HD) from the patient, provider, and payor perspectives. The improved survival and reduced morbidity observed in studies conducted outside the US, as well as the reduced hospitalization, are attractive for each stakeholder. We also consider the potential barriers to greater utilization of HDF therapies, including unfounded concerns regarding additional costs of HDF, e.g., for the preparation and microbial testing of quality of substitution fluids. Ultrapure fluids are easily attainable and prepared from dialysis fluids using established "online" (OL) technologies. OL-HDF has matured to a level whereby little additional effort is required to safely implement it as all modern machine systems are today equipped with the OL-HDF functionality. Countries already convinced of the advantages of HF-HD are thus well positioned to make the transition to OL-HDF to achieve further clinical and associated economic benefits. Healthcare systems struggling to cope with the increasing demand for HD therapies would therefore, like patients, be beneficiaries in the long term with increased usage of OL-HDF for end stage kidney disease patients.

Choices in hemodialysis therapies: variants, personalized therapy and application of evidence-based medicine

The extent of removal of the uremic toxins in hemodialysis (HD) therapies depends primarily on the dialysis membrane characteristics and the solute transport mechanisms involved. While designation of ‘flux’ of membranes as well toxicity of compounds that need to be targeted for removal remain unresolved issues, the relative role, efficiency and utilization of solute removal principles to optimize HD treatment are better delineated. Through the combination and intensity of diffusive and convective removal forces, levels of concentrations of a broad spectrum of uremic toxins can be lowered significantly and successfully. Extended clinical experience as well as data from several clinical trials attest to the benefits of convection-based HD treatment modalities. However, the mode of delivery of HD can further enhance the effectiveness of therapies. Other than treatment time, frequency and location that offer clinical benefits and increase patient well-being, treatment- and patient-specific criteria may be tailored for the therapy delivered: electrolytic composition, dialysate buffer and concentration and choice of anticoagulating agent are crucial for dialysis tolerance and efficacy. Evidence-based medicine (EBM) relies on three tenets, i.e. clinical expertise (i.e. doctor), patient-centered values (i.e. patient) and relevant scientific evidence (i.e. science), that have deviated from their initial aim and summarized to scientific evidence, leading to tyranny of randomized controlled trials. One must recognize that practice patterns as shown by Dialysis Outcomes and Practice Patterns Study and personalization of HD care are the main driving force for improving outcomes. Based on a combination of the three pillars of EBM, and particularly on bedside patient–clinician interaction, we summarize what we have learned over the last 6 decades in terms of best practices to improve outcomes in HD patients. Management of initiation of dialysis, vascular access, preservation of kidney function, selection of biocompatible dialysers and use of dialysis fluids of high microbiological purity to restrict inflammation are just some of the approaches where clinical experience is vital in the absence of definitive scientific evidence. Further, HD adequacy needs to be considered as a broad and multitarget approach covering not just the dose of dialysis provided, but meeting individual patient needs (e.g. fluid volume, acid–base, blood pressure, bone disease metabolism control) through regular assessment—and adjustment—of a series of indicators of treatment efficiency. Finally, in whichever way new technologies (i.e. artificial intelligence, connected health) are embraced in the future to improve the delivery of dialysis, the human dimension of the patient–doctor interaction is irreplaceable. Kidney medicine should remain ‘an art’ and will never be just ‘a science’.

Healthy Lifestyle and Mortality Among Adults Receiving Hemodialysis: The DIET-HD Study

RATIONALE & OBJECTIVE

A healthy lifestyle promotes cardiovascular health and reduces cardiac-related mortality in the general population but its benefits for people receiving maintenance hemodialysis are uncertain.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

5,483 of 9,757 consecutive adults receiving maintenance hemodialysis (January 2014 to June 2017, median dialysis vintage: 3.6 yrs) in a multinational private dialysis network and with complete lifestyle data.

EXPOSURES

Based on the American Heart Association's recommendations for cardiovascular prevention, a modified healthy lifestyle score was the sum of four components addressing use of smoking tobacco, physical activity, diet, and control of systolic blood pressure.

OUTCOMES

Cardiovascular and all-cause mortality.

ANALYTICAL APPROACH

Adjusted proportional hazards (aHRs) regression analyses with country as a random effect to estimate the associations between lifestyle score (low [0-2 points] as the referent, medium [3-5], and high [6-8]) and mortality. Associations were expressed as aHRs with 95% confidence intervals (CIs).

RESULTS

During a median of 3.8 years (17,451 person-years in total), there were 2,163 deaths, of which 826 were related to cardiovascular disease. Compared to patients with a low lifestyle score, the aHRs (95% CIs) for all-cause mortality among those with medium and high lifestyle scores were 0.75 (0.65-0.85) and 0.64 (0.54-0.76), respectively. Compared to patients with a low lifestyle score, the aHRs (95% CIs) for cardiovascular mortality among those with medium and high lifestyle scores were 0.73 (0.59-0.91) and 0.65 (0.49-0.85), respectively.

LIMITATIONS

Self-reported lifestyle, data-driven approach.

CONCLUSIONS

A healthier lifestyle is associated with lower all-cause and cardiovascular mortality among patients receiving maintenance hemodialysis.

Dietary Potassium Intake and Mortality in a Prospective Hemodialysis Cohort

OBJECTIVES

Among hemodialysis patients, clinical practice guidelines recommend dietary potassium restriction given concerns about potential hyperkalemia leading to malignant arrhythmias and mortality. However, there are sparse data informing recommendations for dietary potassium intake in this population. We thus sought to examine the relationship between dietary potassium intake and death risk in a prospective cohort of hemodialysis patients.

DESIGN AND METHODS

Among 415 hemodialysis patients from the prospective "Malnutrition, Diet, and Racial Disparities in Chronic Kidney Disease" cohort recruited across 16 outpatient dialysis clinics, information regarding dietary potassium intake was obtained using Food Frequency Questionnaires administered over October 2011 to March 2015. We first examined associations of baseline dietary potassium intake categorized as tertiles with mortality risk using Cox regression. We then examined clinical characteristics associated with low dietary potassium intake (defined as the lowest tertile) using logistic regression.

RESULTS

In expanded case-mix Cox analyses, patients whose dietary potassium intake was in the lowest tertile had higher mortality (ref: highest tertile) (adjusted hazard ratio 1.74, 95% confidence interval 1.14-2.66). These associations had even greater magnitude of risk following adjustment for laboratory and nutritional covariates (adjusted hazard ratio 2.65, 95% confidence interval 1.40-5.04). In expanded case-mix restricted cubic spline analyses, there was a monotonic increase in mortality risk with incrementally lower dietary potassium intake. In expanded case-mix logistic regression models, female sex; higher serum bicarbonate; and lower dietary energy, protein, and fiber intake were associated with low dietary potassium intake.

CONCLUSIONS

In a prospective cohort of hemodialysis patients, lower dietary potassium intake was associated with higher mortality risk. These findings suggest that excessive dietary potassium restriction may be deleterious in hemodialysis patients, and further studies are needed to determine the optimal dietary potassium intake in this population.

Electrolyte Changes in Contemporary Hemodialysis: A Secondary Analysis of the Monitoring in Dialysis (MiD) Study

BACKGROUND

There is a paucity of contemporary data examining electrolyte changes during and immediately after hemodialysis (HD), and their relationship with dialysate prescriptions. The present study examines these relationships.

METHODS

We analyzed patient- (n=66) and HD session-level pre- and post-dialysis laboratory data (n=1,713) over a six-month period from the Monitoring in Dialysis Study. We fit mixed effects regression models to analyze electrolyte, blood urea nitrogen, creatinine, and albumin levels immediately post-HD, accounting for pre-HD and dialysate prescriptions. In a subset of US patients (n=40), 15-minute post-HD and 30-minute post-HD values were available at one session. Predictive models were fit to estimate electrolyte levels immediately post-HD, accounting for pre-HD concentrations and dialysate prescriptions.

RESULTS

Serum bicarbonate, calcium, and albumin increased (mean increase 4.9±0.3 mEq/L, 0.7±0.1 mEq/L, and 0.4±0.03 g/dL, respectively), whereas potassium, magnesium, and phosphorus decreased immediately post-HD (mean -1.2±0.1 mEq/L, -0.3±0.03 mEq/L, and -3.0±0.2 mg/dL, respectively). Hypokalemia and hypophosphatemia were present in 40% of and 67% of immediate post-HD samples, respectively. Dynamic changes were observed in electrolyte concentrations at 15- and 30-minutes post-HD, compared to immediately post-HD.

CONCLUSION

We describe the magnitude of post-dialytic changes in serum electrolytes with contemporary HD, reporting a high incidence of electrolyte abnormalities post-HD, and present predictive nomograms relating electrolyte changes immediately post-HD to dialysate prescriptions. Our results may be useful for clinical care and provide insights for future research on dialysate prescriptions.

Dialysis-Induced Cardiovascular and Multiorgan Morbidity

Hemodialysis has saved many lives, albeit with significant residual mortality. Although poor outcomes may reflect advanced age and comorbid conditions, hemodialysis per se may harm patients, contributing to morbidity and perhaps mortality. Systemic circulatory "stress" resulting from hemodialysis treatment schedule may act as a disease modifier, resulting in a multiorgan injury superimposed on preexistent comorbidities. New functional intradialytic imaging (i.e., echocardiography, cardiac magnetic resonance imaging [MRI]) and kinetic of specific cardiac biomarkers (i.e., Troponin I) have clearly documented this additional source of end-organ damage. In this context, several factors resulting from patient-hemodialysis interaction and/or patient management have been identified. Intradialytic hypovolemia, hypotensive episodes, hypoxemia, solutes, and electrolyte fluxes as well as cardiac arrhythmias are among the contributing factors to systemic circulatory stress that are induced by hemodialysis. Additionally, these factors contribute to patients' symptom burden, impair cognitive function, and finally have a negative impact on patients' perception and quality of life. In this review, we summarize the adverse systemic effects of current intermittent hemodialysis therapy, their pathophysiologic consequences, review the evidence for interventions that are cardioprotective, and explore new approaches that may further reduce the systemic burden of hemodialysis. These include improved biocompatible materials, smart dialysis machines that automatically may control the fluxes of solutes and electrolytes, volume and hemodynamic control, health trackers, and potentially disruptive technologies facilitating a more personalized medicine approach.

Variations in Magnesium Concentration Are Associated with Increased Mortality: Study in an Unselected Population of Hospitalized Patients

Dysmagnesemia is a serious disturbance of microelement homeostasis. The aim of this study was to analyze the distribution of serum magnesium concentrations in hospitalized patients according to gender, age, and result of hospitalization. The study was conducted from February 2018 to January 2019 at the Central Clinical Hospital in Warsaw. Laboratory test results from 20,438 patients were included in this retrospective analysis. When a lower reference value 0.65 mmol/L was applied, hypermagnesemia occurred in 196 patients (1%), hypomagnesemia in 1505 patients (7%), and normomagnesemia in 18,711 patients (92%). At a lower reference value of 0.75 mmol/L, hypomagnesemia was found in 25% and normomagnesemia in 74% of patients. At a lower reference value of 0.85 mmol/L, hypomagnesemia was found in 60% and normomagnesemia in 39% of patients. Either hypo- or hyper-magnesemia was associated with increased risk of in-hospital mortality. This risk is the highest in patients with hypermagnesemia (40.1% of deaths), but also increases inversely with magnesium concentration below 0.85 mmol/L. Serum magnesium concentration was not gender-dependent, and there was a slight positive correlation with age (p < 0.0001, r = 0.07). Large fluctuations in serum magnesium level were associated with increased mortality (p = 0.0017). The results indicate that dysmagnesemia is associated with severe diseases and generally severe conditions. To avoid misdiagnosis, an increase of a lower cut-off for serum magnesium concentration to at least 0.75 mmol/L is suggested.

Optimization of dialysate bicarbonate in patients treated with online haemodiafiltration

Background

Metabolic acidosis is a common problem in haemodialysis patients, but acidosis overcorrection has been associated with higher mortality. There is no clear definition of the optimal serum bicarbonate target or dialysate bicarbonate. This study analysed the impact of reducing dialysate bicarbonate from 35 to 32 mEq/L on plasma bicarbonate levels in a cohort of patients treated with online haemodiafiltration (OL-HDF).

Methods

We performed a prospective cohort study with patients in a stable chronic OL-HDF programme for at least 12 months in the Hospital Clinic of Barcelona. We analysed pre- and post-dialysis total carbon dioxide(TCO₂₎ before and after dialysate bicarbonate reduction from 35 to 32 mEq/L, as well as the number of patients with a pre- and post-dialysis TCO₂ within 19–25 and ≤29 mEq/L, respectively, after the bicarbonate modification. Changes in serum sodium, potassium, calcium, phosphorous and parathyroid hormone (PTH) were also assessed.

Results

We included 84 patients with a 6-month follow-up. At 6 months, pre- and post-dialysis TCO₂ significantly decreased (26.78 ± 1.26 at baseline to 23.69 ± 1.92 mEq/L and 31.91 ± 0.91 to 27.58 ± 1.36 mEq/L, respectively). The number of patients with a pre-dialysis TCO₂ >25 mEq/L was significantly reduced from 80 (90.5%) to 17 (20.2%) and for post-dialysis TCO₂  >29 mEq/L this number was reduced from 83 (98.8%) to 9 (10.7%). PTH significantly decreased from 226.09 (range 172–296) to 182.50 (125–239)  pg/mL at 6 months (P < 0.05) and post-dialysis potassium decreased from 3.16 ± 0.30 to 2.95 ± 0.48 mEq/L at 6 months (P < 0.05). Sodium, pre-dialysis potassium, calcium and phosphorous did not change significantly.

Conclusions

Reducing dialysate bicarbonate concentration by 3 mEq/L significantly and safely decreased pre- and post-dialysis TCO₂, avoiding acidosis overcorrection and improving secondary hyperparathyroidism control. An individualized bicarbonate prescription (a key factor in the adequate control of acidosis) according to pre-dialysis TCO₂ is suggested based on these results.

Residual Urine Output and Mortality in a Prospective Hemodialysis Cohort

Introduction

Although residual urine output (UOP) is associated with better survival and quality of life in dialysis patients, frequent measurement by 24-hour urine collection is burdensome. We thus sought to examine the association of patients’ self-reported residual UOP, as an alternative proxy of measured residual UOP, with mortality risk in a prospective hemodialysis cohort study.

Methods

Among 670 hemodialysis patients from the prospective multicenter Malnutrition, Diet, and Racial Disparities in Kidney Disease study, we examined associations of residual UOP, ascertained by patient self-report, with all-cause mortality. Patients underwent protocolized surveys assessing presence and frequency of UOP (absent, every 1–3 days, >1 time per day) every 6 months from 2011 to 2015. We examined associations of baseline and time-varying UOP with mortality using Cox regression.

Results

In analyses of baseline UOP, absence of UOP was associated with higher mortality in expanded case-mix adjusted Cox models (ref: presence of UOP): hazard ratio (HR), 1.78 (95% confidence interval [CI], 1.16–2.72). In analyses examining baseline frequency of UOP, point estimates suggested a graded association between lower frequency of UOP and higher mortality, although estimates for UOP every 1 to 3 days did not reach statistical significance (reference: UOP >1 time per day): HR, 1.29 (95% CI, 0.82–2.05) and HR, 1.97 (95% CI, 1.24–3.12) for UOP every 1 to 3 days and absence of UOP, respectively. Similar findings were observed in analyses of time-varying UOP.

Conclusion

In hemodialysis patients, there is a graded association between lower frequency of self-reported UOP and higher mortality. Further studies are needed to determine the clinical impact of more frequent assessment of residual UOP using self-reported methods.

A simple modification of dialysate potassium: its impact on plasma potassium concentrations and the electrocardiogram

Background

Sudden death is frequent in haemodialysis (HD) patients. Both hyperkalaemia and change of plasma potassium (K) concentrations induced by HD could explain this. The impact of increasing dialysate K by 1 mEq/L on plasma K concentrations and electrocardiogram (ECG) results before and after HD sessions was studied.

Methods

Patients with pre-dialysis K >5.5 mEq/L were excluded. ECG and K measurements were obtained before and after the first session of the week for 2 weeks. Then, K in the dialysate was increased (from 1 or 3 to 2 or 4 mEq/L, respectively). Blood and ECG measurements were repeated after 2 weeks of this change.

Results

Twenty-seven prevalent HD patients were included. As expected, a significant decrease in K concentrations was observed after the dialysis session, but this decrease was significantly lower after the switch to an increased dialysate K. The pre-dialysis K concentrations were not different after changing, but post-dialysis K concentrations were higher after switching (P < 0.0001), with a lower incidence of post-dialysis hypokalaemia. Regarding ECG, before switching, the QT interval (QT) dispersion increased during the session, whereas no difference was observed after switching. One week after switching, post-dialysis QT dispersion [38 (34-42) ms] was lower than post-dialysis QT dispersion 2 weeks and 1 week before switching [42 (38-57) ms, P = 0.0004; and 40 (35-50) ms, P = 0.0002].

Conclusions

A simple increase of 1 mEq/L of K in the dialysate is associated with a lower risk of hypokalaemia and a lower QT dispersion after the dialysis session. Further study is needed to determine if such a strategy is associated with a lower risk of sudden death.

Hemodialysis Procedure-Associated Autonomic Imbalance and Cardiac Arrhythmias: Insights From Continuous 14-Day ECG Monitoring

Background

In patients with end‐stage kidney disease, sudden cardiac death is more frequent after a long interdialytic interval, within 6 hours after the end of a hemodialysis session. We hypothesized that the occurrence of paroxysmal arrhythmias is associated with changes in heart rate and heart rate variability in different phases of hemodialysis.

Methods and Results

We conducted a prospective ancillary study of the Predictors of Arrhythmic and Cardiovascular Risk in End Stage Renal Disease cohort. Continuous ECG monitoring was performed using an ECG patch, and short‐term heart rate variability was measured for 3 minutes every hour (by root mean square of the successive normal‐to‐normal intervals, spectral analysis, Poincaré plot, and entropy), up to 300 hours. Out of enrolled participants (n=28; age 54±13 years; 57% men; 96% black; 33% with a history of cardiovascular disease; left ventricular ejection fraction 70±9%), arrhythmias were detected in 13 (46%). Nonsustained ventricular tachycardia occurred more frequently during/posthemodialysis than pre‐/between hemodialysis (63% versus 37%, P=0.015). In adjusted for cardiovascular disease time‐series analysis, nonsustained ventricular tachycardia was preceded by a sudden heart rate increase (by 11.2 [95% CI 10.1–12.3] beats per minute; P<0.0001). During every‐other‐day dialysis, root mean square of the successive normal‐to‐normal intervals had a significant circadian pattern (Mesor 10.6 [ 95% CI 0.9–11.2] ms; amplitude 1.5 [95% CI 1.0–3.1] ms; peak at 02:01 [95% CI 20:22–03:16] am; P<0.0001), which was replaced by a steady worsening on the second day without dialysis (root mean square of the successive normal‐to‐normal intervals −1.41 [95% CI −1.67 to −1.15] ms/24 h; P<0.0001).

Conclusions

Sudden increase in heart rate during/posthemodialysis is associated with nonsustained ventricular tachycardia. Every‐other‐day hemodialysis preserves circadian rhythm, but a second day without dialysis is characterized by parasympathetic withdrawal.