Fluid retention is associated with cardiovascular mortality in patients undergoing long-term hemodialysis

Dialysis parameters associated with SARS-CoV-2 infection and prognosis in end-stage kidney disease

BACKGROUND

The Covid-19 pandemic has affected patients with end-stage kidney disease (ESKD). Whether dialysis parameters have a prognostic value in ESKD patients with Covid-19 remains unclear.

MATERIALS AND METHODS

We retrospectively evaluated clinical characteristics, blood pressure (BP) and dialysis parameters in ESKD patients undergoing maintenance outpatient hemodialysis, with (Covid-ESKD) and without (No-Covid-ESKD) Covid-19, at four Brazilian hemodialysis facilities. The Covid-ESKD (n = 107; 54% females; 60.8 ± 17.7 years) and No-Covid-ESKD (n = 107; 62% females; 58.4 ± 14.6 years) groups were matched by calendar time. The average BP and dialysis parameters were calculated during the pre-infection, acute infection, and post-infection periods. The main outcomes were Covid-19 hospitalization and all-cause mortality.

RESULTS

Covid-ESKD patients had greater intradialytic and postdialysis systolic BP and lower predialysis weight, postdialysis weight, ultrafiltration rate, and interdialytic weight gain during acute-illness compared to 1-week-before-illness, while these changes were not observed in No-Covid-ESKD patients. After 286 days of follow-up (range, 276-591), there were 18 Covid-19-related hospitalizations and 28 deaths among Covid-ESKD patients. Multivariable logistic regression analysis showed that increases in predialysis systolic BP from 1-week-before-illness to acute-illness (OR, 95%CI = 1.06, 1.02-1.10; p = .004) and Covid-19 vaccination (OR, 95%CI = 0.16, 0.04-0.69; p = .014) were associated with hospitalization in Covid-ESKD patients. Multivariable Cox-regression analysis showed that Covid-19-related hospitalization (HR, 95%CI = 5.17, 2.07-12.96; p < .001) and age (HR, 95%CI = 1.05, 1.01-1.08; p = .008) were independent predictors of all-cause mortality in Covid-ESKD patients.

CONCLUSION

Acute Covid-19 illness is associated with variations in dialysis parameters of volume status in patients with ESKD. Furthermore, increases in predialysis BP during acute Covid-19 illness are associated with an adverse prognosis in Covid-ESKD patients.

Effect of long-term serum sodium levels on the prognosis of patients on maintenance hemodialysis

Abnormal serum Na (SNa) levels are common in patients with chronic kidney disease (CKD) which is associated with increased morbidity and mortality. There are relatively few studies on the effect of SNa indicators on the prognosis of patients undergoing maintenance hemodialysis (MHD). We aim to investigate the effect of long-term SNa levels on the survival and prognosis of patients undergoing hemodialysis (HD). Newly entered HD patients in the registration system of Zhejiang Provincial Dialysis Quality Control Center between January 1, 2010 and December 31, 2019 were included and followed up until December 31, 2020. Multiple sodium levels were collected from patients, defining long-term SNa as the mean of multiple SNa, according to which patients were grouped, with the prognostic differences between subgroups compared by Kaplan-Meier modeling and multifactorial Cox regression modeling. Finally, a total of 21,701 patients were included in this study and Cox regression showed that decreased SNa levels (Na < 135 mmol/L, HR = 1.704, 95% CI 1.408-2.063, p < 0.001; 135≦Na≦137.5 mmol/L, HR = 1.127,95% CI 1.016-1.250, p = 0.024) and elevated SNa levels (142.5 < Na≦145mmol/L, HR = 1.198, 95% CI 1.063-1.350, p = 0.003; Na > 145mmol/L, HR = 2.150, 95% CI 1.615-2.863, p < 0.001) were all independent risk factors for all-cause mortality in MHD patients.

Changes in right ventricular dimensions, function, and pulmonary circulation loading according to the degree of interdialytic weight gain in maintenance hemodialysis patients

INTRODUCTION

The aim of this study was to investigate changes in echocardiographic right ventricular (RV) indices in relation to the degree of fluid accumulation between hemodialysis sessions, evaluated according to the recommended threshold of interdialytic-weight-gain corrected for dry weight (IDWG%).

METHODS

A post-hoc analysis was performed using data from 41 maintenance hemodialysis patients. Patients were divided into a higher (>4.5%) and a lower (<4.5%) IDWG% group and underwent an echocardiographic assessment at the start and the end of the 3-day and the 2-day interdialytic interval.

RESULTS

RV systolic pressure (RVSP) increments were more pronounced in the higher compared to the lower IDWG% group (16.43 ± 5.37 vs. 14.11 ± 13.38 mm Hg respectively, p = 0.015) over the 3-day interval, while changes in RV filling pressures, did not differ significantly between the groups (p = 0.84).

CONCLUSIONS

During the 3-day interdialytic interval, pulmonary circulation is particularly overloaded in patients with fluid accumulation higher than the recommended thresholds, as evidenced by higher RVSP elevations.

Management of patients with heart failure and chronic kidney disease

Chronic kidney disease (CKD) and heart failure are often co-existing conditions due to a shared pathophysiological process involving neurohormonal activation and hemodynamic maladaptation. A wide range of pharmaceutical and interventional tools are available to patients with CKD, consisting of traditional ones with decades of experience and newer emerging therapies that are rapidly reshaping the landscape of medical care for this population. Management of patients with heart failure and CKD requires a stepwise approach based on renal function and the clinical phenotype of heart failure. This is often challenging due to altered drug pharmacokinetics interactions with various degrees of kidney function and frequent adverse effects from the therapy that lead to poor patient tolerance. Despite a great body of clinical evidence and guidelines that have offered various treatment options for patients with heart failure and CKD, respectively, patients with CKD are still underrepresented in heart failure clinical trials, especially for those with advanced CKD and end-stage renal disease (ESRD). Future studies are needed to better understand the generalizability of these therapeutic options among heart failures with different stages of CKD.

Interdialytic weight gain and low dialysate sodium concentration in patients on chronic hemodialysis: a systematic review and meta-analysis

PURPOSE

The present systematic review and meta-analysis aimed at evaluating the effect of low dialysate sodium concentration on interdialytic weight gain (IDWG) in chronic hemodialysis patients.

METHODS

Studies were eligible for inclusion if they were English language papers published in a peer-reviewed journal and met the following inclusion criteria: (1) studies in adult patients (over 18 years of age), (2) included patients on chronic hemodialysis since at least 6 months; (3) compared standard (138-140 mmol/l) or high (> 140 mmol/l) dialysate sodium concentration with low (< 138 mmol/l) dialysate sodium concentration; (4) Included one outcome of interest: interdialytic weight gain. Medline, PubMed, Web of Science, and the Cochrane Library were searched for the quality of reporting for each study was performed using the Quality Assessment Tool of Controlled Intervention Studies of the National Institutes of Health. The quality of reporting of each cross-over study was performed using the Revised Cochrane Risk of Bias (RoB) tool for cross-over trials as proposed by Ding et al. RESULTS: Nineteen studies (710 patients) were included in the analysis: 15 were cross-over and 4 parallel randomized controlled studies. In cross-over studies, pooled analysis revealed that dialysate sodium concentration reduced IDWG with a pooled MD of - 0.40 kg (95% CI - 0.50 to - 0.30; p < 0.001). The systematic review of four parallel, randomized, studies revealed that the use of a low dialysate sodium concentration was associated with a significant reduction of the IDWG in two studies, sustained and almost significant (p = 0.05) reduction in one study, and not significant reduction in one study.

CONCLUSION

Low dialysate sodium concentration reduces the IDWG in prevalent patients on chronic hemodialysis.

Diuretic prescriptions in the first year of haemodialysis: international practice patterns and associations with outcomes

Background

The use of diuretics in patients on haemodialysis (HD) is thought to maintain diuresis. However, this assumption and the optimal dose are based on little scientific evidence, and associations with clinical outcomes are unclear.

Methods

We reported international variations in diuretic use and loop diuretic dose across 27 759 HD patients with dialysis vintage <1 year in the Dialysis Outcomes and Practice Patterns Study phases 2-5 (2002-2015), a prospective cohort study. Doses of torsemide (4:1) and bumetanide (80:1) were converted to oral furosemide-equivalent doses. Adjusted Cox, logistic and linear regressions were used to investigate the association of diuretic use and dose with outcomes.

Results

Diuretic utilization varied widely by country at vintage <3 months, ranging from >80% in Germany and Sweden to <35% in the USA, at a median dose ranging from 400-500 mg/day in Germany and Sweden to <100 mg/day in Japan and the USA. Neither diuretic use nor higher doses were associated with a lower risk of all-cause mortality, a higher risk of hospitalization for fracture or elevated parathyroid hormone levels, but the prescription of higher doses (>200 mg/day) was associated with a higher risk of all-cause hospitalization.

Conclusions

Substantial international differences exist in diuretic prescriptions, with use and doses much higher in some European countries than the USA. The prescription and higher doses of loop diuretics was not associated with improved outcomes.

Interdialytic weight gain and low-salt diet in patients on chronic hemodialysis: A systematic review and meta-analysis

OBJECTIVE

The present systematic review and meta-analysis aims to determine the difference in the interdialytic weight gain (IDWG) between low salt intake diet and normal/high salt intake diet or between nutritional counseling aimed at reducing diet salt intake and no nutritional counseling in patients on chronic hemodialysis.

METHODS

Medline, PubMed, Web of Science, and the Cochrane Library were searched. Randomized, crossover or parallel studies and observational studies were considered for inclusion and: 1) included adult patients on chronic hemodialysis since at least 6 months; 2) compared normal salt intake diet with low salt intake diet on IDWG; 3) compared nutritional counseling aimed at reducing diet salt intake with no intervention on IDWG; 4) reported on IDWG.

RESULTS

Eight articles (783 patients) were fully assessed for eligibility and included in the investigation. Meta-analysis showed frequencies of patients that increased their weight after dialysis more than 2.5 Kg (events) over total enrolled subjects for each group (control and experimental). As no significant heterogeneity was observed (I2 = 8%; p = 0.36), the pooled analysis was performed using a fixed-effect model. Funnel plot was generated and no obvious asymmetry was observed. The Overall Odds Ratio to get an event in the experimental group, in respect to controls, is 0.57 (0.33-0.97) (p = 0.04] with single studies OR ranging between 0.11 and 1.08.

CONCLUSION

The present systematic review and meta-analysis suggest that the use of a low salt diet sodium or a nutritional counseling aimed at reducing diet salt intake is associated with a statistically significant reduction of the IDWG in patients on chronic hemodialysis.

Coronary Artery Disease in Patients Undergoing Hemodialysis: A Problem that Sounds the Alarm

Chronic kidney disease (CKD) is affecting more and more individuals over time. The importance of the increased prevalence is enhanced by the close association with the increased risk of poor individual outcomes such as death, fatal and non-fatal cardiovascular (CV) events and progression to end stage kidney disease (ESKD). ESKD requires replacement treatment such as hemodialysis (HD), a particular and complex context that unfortunately has been rarely considered in observational studies in the last few decades. The current perspective of HD as a bridge to kidney transplant requires greater attention from observational and experimental research both in the prevention and treatment of CV events in ESKD patients. We present a narrative review by performing a literature review to extrapolate the most significant articles exploring the CV risk, in particular coronary artery disease (CAD), in ESKD and evaluating possible innovative diagnostic and therapeutic tools in these patients. The risk of CAD increases linearly when the estimated glomerular filtration rate (eGFR) declines and reached the most significant level in ESKD patients. Several diagnostic techniques have been evaluated to predict CAD in ESKD such as laboratory tests (Troponin-T, N-terminal pro b-type natriuretic peptide, alkaline phosphatase), echocardiography and imaging techniques for vascular calcifications evaluation. Similarly, treatment is based on lifestyle changes, medical therapy and invasive techniques such as coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). Unfortunately in the literature there are no clear indications of the usefulness and validity of biomarkers and possible treatments in ESKD patients. Considering the ESKD weight in terms of prevalence and costs it is necessary to implement clinical research in order to develop prognostic reliable biomarkers for CV and CAD risk prediction, in patients with ESKD. It should be highlighted that HD is a peculiar setting that offers the opportunity to implement research and facilitates patient monitoring by favoring the design of clinical trials.

Effects of Kt/Vurea on outcomes according to age in patients on maintenance hemodialysis

Background

The guidelines recommended target and minimum single-pool Kt/Vurea are 1.4 and 1.2, respectively, in hemodialysis patients. However, the optimal hemodialysis dose remains controversial. We investigated the effects of Kt/Vurea on patient outcomes according to age, with a focus on older patients.

Methods

This study used the hemodialysis quality assessment program and claims datasets. Patients were divided into four subgroups according to age (<65, 65-74, 75-84, and ≥85 years). Each group was divided into three subgroups according to Kt/Vurea : reference (ref) (1.2 ≤ Kt/Vurea ≤ 1.4), low (< 1.2), and high (> 1.4).

Results

The low, ref, and high Kt/Vurea groups included 1668, 8156, and 16 546 (< 65 years); 474, 3058, and 7646 (65-74 years); 225, 1362, and 4194 (75-84 years); and 14, 126, and 455 (≥85 years) patients, respectively. The low Kt/Vurea group had higher mortality rates than the ref Kt/Vurea group irrespective of age [adjusted hazard ratio (aHR), 95% confidence interval (CI): 1.23, 1.11-1.36; 1.14, 1.00-1.30; 1.28, 1.09-1.52; and 2.10, 1.16-3.98, in patients aged <65, 65-74, 75-84, and ≥85 years, respectively]. The high Kt/Vurea group had lower mortality rates than the ref Kt/Vurea group in patients aged <65 and 65-74 years (aHR, 95% Cl: 0.87, 0.82-0.92 and 0.93, 0.87-0.99 in patients aged <65 and 65-74 years, respectively).

Conclusions

These results support the current recommendations of a minimum Kt/Vurea of 1.2 even in patients age ≥85 years. In young patients, Kt/Vurea above the recommended threshold can be beneficial for survival.

Lung Ultrasound and Bioelectrical Impedance Analysis for Fluid Status Assessing Patients Undergoing Maintenance Hemodialysis

Background

Volume overload is a fatal complication for people undergoing hemodialysis. Therefore, regulating a patient's "dry weight" based on their fluid status is imperative. Clinical experiences are too subjective to accurately judge a patient's fluid status, but techniques have emerged for improved fluid control in the two decades. Specifically, lung ultrasonography (LUS) uses a unique aspect of ultrasound images, the B-lines, to evaluate extravascular lung water, which has increasingly attracted attention. However, the role of B-line quantification in predicting short-mid-term death and/or cardiovascular complications is unclear.

Methods

Patients undergoing MHD at the hemodialysis center of Zhejiang Provincial People's Hospital from October 1, 2020, to February 28, 2021, were examined using LUS and a bioelectrical impedance analysis before and after dialysis, and related clinical data were collected. All patients were followed up for one year after the examination, and deaths and first cardiovascular events (e.g., stroke, myocardial infarction, and heart failure) during this period were recorded.

Results

98 patients were enrolled and divided into three groups in relation to their mild (<16 B-lines), moderate (16-30 B-lines), or severe (>30 B-lines) hypervolemia, defined by the number of B-lines. The long-term survival rate was significantly lower in the severe group than in the mild and moderate groups. LUS and bioelectrical impedance-related parameters (e.g., extracellular water-to-water ratio) were closely related to cardiac ultrasound parameters (left ventricular ejection fraction) (P < 0.001). The optimal B-line cutoff value on LUS for predicting fluid overload (defined clinically) in patients on hemodialysis was 11.5 lines (AUC = 0.840, 95% confidence interval 0.735-0.945, P < 0.001), and the diagnostic sensitivity and specificity were both 76.5%. During the one-year follow-up period, ten deaths and six cardiovascular events occurred. The survival rate was significantly lower in the severe group than in the mild group (log-rank test χ2 = 10.050, P=0.002) but did not differ between the severe and moderate groups (χ2 = 2.629, P=0.105).

Conclusion

LUS is a cheap, noninvasive, simple, and repeatable volume-monitoring method that can assist with individualized fluid volume management in patients undergoing MHD. LUS results may also help to predict the short-mid-term survival rate of patients to a certain extent.

Is increased subjective thirst associated with greater interdialytic weight gains, extracellular fluid and dietary sodium intake?

BACKGROUND

Some previous studies have reported an effect of increasing subjective thirst and interdialytic weight gains (IDWG), and that this may be influenced by nonadherence to dietary sodium restrictions, whereas others reported no such association. As such we wished to review the effect of self-reported thirst on IDWGs and dietary sodium intake.

METHODS

Dialysis patients were asked to complete visual analogues thirst, distress thermometer (DT) scores and complete a sodium food frequency questionnaire (SFFQ). IDWG and pre and post dialysis volumes were measured with multifrequency bioelectrical impedance.

RESULTS

One hundred and eleven patients completed the questionnaires and had bioimpedance measurements: 63% male, mean age 63.8 ± 16.1 years, 33% diabetic with a median thirst score 3 (0-5) and SFFQ 52.0 ± 18, and IDWG 2.1 ± 1.3%. Thirst was associated with DT (r = 0.28, p = 0.004) and negatively with age (r = -0.31, p < 0.001), but not SFFQ, IDWG, extracellular water, or dialysate sodium, or dialysate to plasma gradient. Patients with higher thirst scores were younger (58.0 ± 15.2 vs. 69.4 ± 15.0 years, p < 0.001) with higher DT scores (5 [2-7] vs. 2 [0-5], p < 0.001). On multivariate logistic analysis, only age was associated with self-reported thirst (odds ratio 0.95, 95% confidence limits 0.92-0.98, p < 0.001).

CONCLUSION

We found that subjective thirst was greater for younger patients and those who reported higher levels of distress, but no association with IDWGs, dietary sodium intake, or dialysate sodium. However, most of our patients followed the dietary advice, as evidenced by the low SFFQ scores and % IDWGs. Whether thirst increases distress or distress increases subjective thirst remains to be determined.

Intravascular volumes and the influence on anemia assessed by a carbon monoxide rebreathing method in patients undergoing maintenance hemodialysis

INTRODUCTION

Fluid overload is a major challenge in hemodialysis patients and might cause hypervolemia. We speculated that hemodialysis patients reaching dry weight could have undetected hypervolemia and low hemoglobin (Hb) concentration (g/dL) due to hemodilution.

METHODS

The study included hemodialysis patients (n = 22) and matched healthy controls (n = 22). Blood volume, plasma volume, red blood cell volume, and total Hb mass were determined using a carbon monoxide (CO)-rebreathing method in hemodialysis patients reaching dry weight and controls. Blood volume measurements were also obtained by a dual-isotope labeling technique in a subgroup for validation purposes.

FINDINGS

In the hemodialysis group, the median specific blood volume was 89.3 mL/kg (interquartile range [IQR]: 76.7-95.4 mL/kg) and was higher than in the control group (79.9 mL/kg [IQR: 70.4-88.0 mL/kg]; p < 0.037). The median specific plasma volume was 54.7 mL/kg (IQR: 47.1-61.0 mL/kg) and 44.0 mL/kg (IQR: 38.7-49.5 mL/kg) in the hemodialysis and control groups, respectively (p < 0.001). Hb concentration was lower in hemodialysis patients (p < 0.001), whereas no difference in total Hb mass was observed between groups (p = 0.11). A correlation was found between blood volume measured by the CO-rebreathing test and the dual-isotope labeling technique in the control group (r = 0.83, p = 0.015), but not the hemodialysis group (r = 0.25, p = 0.60).

DISCUSSION

The hemodialysis group had increased specific blood volume at dry weight due to high plasma volume, suggesting a hypervolemic state. However, correlation was not established against the dual-isotope labeling technique underlining that the precision of the CO-rebreathing test should be further validated. The total Hb mass was similar between hemodialysis patients and controls, unlike Hb concentration, which emphasizes that Hb concentration is an inaccurate marker of anemia among hemodialysis patients.

Sodium handling in pediatric patients on maintenance dialysis

The risk of cardiovascular disease remains exceedingly high in pediatric patients with chronic kidney disease stage 5 on dialysis (CKD 5D). Sodium (Na+) overload is a major cardiovascular risk factor in this population, both through volume-dependent and volume-independent toxicity. Given that compliance with a Na+-restricted diet is generally limited and urinary Na+ excretion impaired in CKD 5D, dialytic Na+ removal is critical to reduce Na+ overload. On the other hand, an excessive or too fast intradialytic Na+ removal may lead to volume depletion, hypotension, and organ hypoperfusion. This review presents current knowledge on intradialytic Na+ handling and possible strategies to optimize dialytic Na+ removal in pediatric patients on hemodialysis (HD) and peritoneal dialysis (PD). There is increasing evidence supporting the prescription of lower dialysate Na+ in salt-overloaded children on HD, while improved Na+ removal may be achieved in children on PD with an individual adaptation of dwell time and volume and with icodextrin use during the long dwell.

Coronary sinus diameter to estimate congestion and predict survival

Background

Congestion predicts a poor prognosis, but its assessment is challenging in clinical practice and requires a multiparametric approach. We investigated if the coronary sinus (CS) diameter can predict mortality in a human model of rapid fluid unloading.

Methods

We measured by echocardiography the CS, and the inferior vena cava (IVC) for comparison, in 60 patients with end-stage chronic kidney disease (ESKD) immediately before and after hemodialysis (HD; age 76 [57-81] years, 40% female, left ventricular ejection fraction 57 [53-56]%). Patients were prospectively followed up for all-cause mortality.

Results

HD-induced decongestion decreased the maximum diameters of both CS and IVC (p ≤ 0.001 for all). The maximum diameter of the CS (CSmax) was as accurate as the IVC maximum diameter and collapsibility for the identification of congestion, defined as pre-hemodialysis status (AUROC CSmax = 0.902 vs IVC = 0.895, p = n.s.). A CSmax diameter after hemodialysis > 9 mm predicted all-cause mortality at 12 months (Log-rank Chi square = 11.49, p < 0.001).

Conclusions

A persistently dilated CS after hemodialysis is a marker of residual congestion and predicts death at one year in high-risk ESKD patients.

Lymphatic vessels and the renin-angiotensin-system

The lymphatic system is an integral part of the circulatory system and plays an important role in the fluid homeostasis of the human body. Accumulating evidence has recently suggested the involvement of lymphatic dysfunction in the pathogenesis of cardio-reno-vascular (CRV) disease. However, how the sophisticated contractile machinery of lymphatic vessels is modulated and, possibly impaired in CRV disease, remains largely unknown. In particular, little attention has been paid to the effect of the renin-angiotensin-system (RAS) on lymphatics, despite the high concentration of RAS mediators that these tissue-draining vessels are exposed to and the established role of the RAS in the development of classic microvascular dysfunction and overt CRV disease. We herein review recent studies linking RAS to lymphatic function and/or plasticity and further highlight RAS-specific signaling pathways, previously shown to drive adverse arterial remodeling and CRV organ damage that have potential for direct modulation of the lymphatic system.

Machine learning-based intradialytic hypotension prediction of patients undergoing hemodialysis: A multicenter retrospective study

BACKGROUND AND OBJECTIVE

Intradialytic hypotension (IDH) is closely associated with adverse clinical outcomes in HD-patients. An IDH predictor model is important for IDH risk screening and clinical decision-making. In this study, we used Machine learning (ML) to develop IDH model for risk prediction in HD patients.

METHODS

62,227 dialysis sessions were randomly partitioned into training data (70%), test data (20%), and validation data (10%). IDH-A model based on twenty-seven variables was constructed for risk prediction for the next HD treatment. IDH-B model based on ten variables from 64,870 dialysis sessions was developed for risk assessment before each HD treatment. Light Gradient Boosting Machine (LightGBM), Linear Discriminant Analysis, support vector machines, XGBoost, TabNet, and multilayer perceptron were used to develop the predictor model.

RESULTS

In IDH-A model, we identified the LightGBM method as the best-performing and interpretable model with C- statistics of 0.82 in Fall30Nadir90 definitions, which was higher than those obtained using the other models (P<0.01). In other IDH standards of Nadir90, Nadir100, Fall20, Fall30, and Fall20Nadir90, the LightGBM method had a performance with C- statistics ranged 0.77 to 0.89. As a complementary application, the LightGBM model in IDH-B model achieved C- statistics of 0.68 in Fall30Nadir90 definitions and 0.69 to 0.78 in the other five IDH standards, which were also higher than the other methods, respectively.

CONCLUSION

Use ML, we identified the LightGBM method as the good-performing and interpretable model. We identified the top variables as the high-risk factors for IDH incident in HD-patient. IDH-A and IDH-B model can usefully complement each other for risk prediction and further facilitate timely intervention through applied into different clinical setting.

Association of extracellular water/total body water ratio with protein-energy wasting and mortality in patients on hemodialysis

Bioimpedance analysis-assessed extracellular water/total body water (ECW/TBW) ratio may be a marker for mortality and poor nutritional status in hemodialysis patients. In 193 maintenance hemodialysis patients, we retrospectively investigated the relationships among ECW/TBW ratio, mortality, and protein-energy wasting (PEW). Four components-body mass index, normalized protein catabolic rate, normalized serum creatinine level, and serum albumin level-constitute the simple PEW score; this score was calculated based on the positive number of items concerning malnutrition among these four components. A score ≥ 3 indicated PEW. Patients were stratified by an ECW/TBW ratio cut-off value (0.40) and by PEW versus non-PEW status. The simple PEW score, cardiothoracic ratio, and log-transformed C-reactive protein level were independently correlated with the ECW/TBW ratio. Eighty-four patients died during follow-up (median 4.3 years). After adjustments for sex, age, hemodialysis vintage, histories of cardiovascular events and diabetes, and C-reactive protein level, a higher ECW/TBW ratio and PEW were independently related to elevated risks of all-cause death. Adding the ECW/TBW ratio to a baseline risk model including PEW significantly increased C-statistics from 0.788 to 0.835. In conclusion, the ECW/TBW ratio may be an indicator of PEW and may be a predictor of death even accounting for PEW, in hemodialysis patients.

Measured sodium excretion is associated with cardiovascular outcomes in non-dialysis CKD patients: results from the KNOW-CKD study

Background

There are insufficient studies on the effect of dietary salt intake on cardiovascular (CV) outcomes in chronic kidney disease (CKD) patients, and there is no consensus on the sodium (Na) intake level that increases the risk of CV disease in CKD patients. Therefore, we investigated the association between dietary salt intake and CV outcomes in CKD patients.

Methods

In the Korean cohort study for Outcome in patients with CKD (KNOW-CKD), 1,937 patients were eligible for the study, and their dietary Na intake was estimated using measured 24h urinary Na excretion. The primary outcome was a composite of CV events and/or all-cause death. The secondary outcome was a major adverse cardiac event (MACE).

Results

Among 1,937 subjects, there were 205 (10.5%) events for the composite outcome and 110 (5.6%) events for MACE. Compared to the reference group (urinary Na excretion< 2.0g/day), the group with the highest measured 24h urinary Na excretion (urinary Na excretion ≥ 8.0g/day) was associated with increased risk of both the composite outcome (hazard ratio 3.29 [95% confidence interval 1.00-10.81]; P = 0.049) and MACE (hazard ratio 6.28 [95% confidence interval 1.45-27.20]; P = 0.013) in a cause-specific hazard model. Subgroup analysis also showed a pronounced association between dietary salt intake and the composite outcome in subgroups of patients with abdominal obesity, female, lower estimated glomerular filtration rate (< 60 ml/min per 1.73m2), no overt proteinuria, or a lower urinary potassium-to-creatinine ratio (< 46 mmol/g).

Conclusion

A high-salt diet is associated with CV outcomes in non-dialysis CKD patients.

Screening and Management of Coronary Artery Disease in Kidney Transplant Candidates

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with chronic kidney disease (CKD), especially in end-stage renal disease (ESRD) patients and during the first year after transplantation. For these reasons, and due to the shortage of organs available for transplant, it is of utmost importance to identify patients with a good life expectancy after transplant and minimize the transplant peri-operative risk. Various conditions, such as severe pulmonary diseases, recent myocardial infarction or stroke, and severe aorto-iliac atherosclerosis, need to be ruled out before adding a patient to the transplant waiting list. The effectiveness of systematic coronary artery disease (CAD) treatment before kidney transplant is still debated, and there is no universal screening protocol, not to mention that a nontailored screening could lead to unnecessary invasive procedures and delay or exclude some patients from transplantation. Despite the different clinical guidelines on CAD screening in kidney transplant candidates that exist, up to today, there is no worldwide universal protocol. This review summarizes the key points of cardiovascular risk assessment in renal transplant candidates and faces the role of noninvasive cardiovascular imaging tools and the impact of coronary revascularization versus best medical therapy before kidney transplant on a patient's cardiovascular outcome.

Management of Cardiovascular Diseases in Chronic Hemodialysis Patients

Hemodialysis (HD) is the main treatment modality for patients with end-stage kidney disease. Cardiovascular diseases (CVD) are highly prevalent in HD patients and are the leading cause of death in this population, with the mortality from CVD approximately 20 times higher than that of the general population. Traditional and non-traditional cardiovascular risk factors accelerate progression of CVD and exacerbate the prognosis in HD patients. This review provides a brief overview of the characteristics of CVD in HD patients, and a description of advances in its management.

Enhancing the Cardiovascular Safety of Hemodialysis Care Using Multimodal Provider Education and Patient Activation Interventions: Protocol for a Cluster Randomized Controlled Trial

BACKGROUND

End-stage kidney disease (ESKD) is treated with dialysis or kidney transplantation, with most patients with ESKD receiving in-center hemodialysis treatment. This life-saving treatment can result in cardiovascular and hemodynamic instability, with the most common form being low blood pressure during the dialysis treatment (intradialytic hypotension [IDH]). IDH is a complication of hemodialysis that can involve symptoms such as fatigue, nausea, cramping, and loss of consciousness. IDH increases risks of cardiovascular disease and ultimately hospitalizations and mortality. Provider-level and patient-level decisions influence the occurrence of IDH; thus, IDH may be preventable in routine hemodialysis care.

OBJECTIVE

This study aims to evaluate the independent and comparative effectiveness of 2 interventions-one directed at hemodialysis providers and another for patients-in reducing the rate of IDH at hemodialysis facilities. In addition, the study will assess the effects of interventions on secondary patient-centered clinical outcomes and examine factors associated with a successful implementation of the interventions.

METHODS

This study is a pragmatic, cluster randomized trial to be conducted in 20 hemodialysis facilities in the United States. Hemodialysis facilities will be randomized using a 2 × 2 factorial design, such that 5 sites will receive a multimodal provider education intervention, 5 sites will receive a patient activation intervention, 5 sites will receive both interventions, and 5 sites will receive none of the 2 interventions. The multimodal provider education intervention involved theory-informed team training and the use of a digital, tablet-based checklist to heighten attention to patient clinical factors associated with increased IDH risk. The patient activation intervention involves tablet-based, theory-informed patient education and peer mentoring. Patient outcomes will be monitored during a 12-week baseline period, followed by a 24-week intervention period and a 12-week postintervention follow-up period. The primary outcome of the study is the proportion of treatments with IDH, which will be aggregated at the facility level. Secondary outcomes include patient symptoms, fluid adherence, hemodialysis adherence, quality of life, hospitalizations, and mortality.

RESULTS

This study is funded by the Patient-Centered Outcomes Research Institute and approved by the University of Michigan Medical School's institutional review board. The study began enrolling patients in January 2023. Initial feasibility data will be available in May 2023. Data collection will conclude in November 2024.

CONCLUSIONS

The effects of provider and patient education on reducing the proportion of sessions with IDH and improving other patient-centered clinical outcomes will be evaluated, and the findings will be used to inform further improvements in patient care. Improving the stability of hemodialysis sessions is a critical concern for clinicians and patients with ESKD; the interventions targeted to providers and patients are predicted to lead to improvements in patient health and quality of life.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03171545; https://clinicaltrials.gov/ct2/show/NCT03171545.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/46187.

Effect of oral nutritional supplementation combined with impedance vectors for dry weight adjustment on the nutritional status, hydration status and quality of life in patients on chronic hemodialysis: A pilot study

BACKGROUND & AIMS

Protein energy wasting frequently affect hemodialysis patients and contribute to the development of overhydration. The objective of this study was to assess the effect of oral nutritional supplementation (ONS) combined with bioelectrical vector analysis (BIVA) on the nutritional and hydration status and the quality of life (QoL) in hemodialysis (HD) patients.

METHODS

Thirty-two chronic HD patients were included in a 6-month randomized pilot study. Patients in SUPL group received a simultaneous intervention consisting of a personalized diet, 245 mL/d ONS and dry weight adjustment through BIVA. Patients in CON group received a personalized diet and dry weight adjustment by BIVA. Anthropometrical, biochemical, dietary, QoL, handgrip strength (HGS) and bioimpedance measurements were performed. Malnutrition Inflammation Score (MIS) was applied.

RESULTS

At the end of the intervention, moderate undernutrition decreased by 43.8% in SUPL group while in CON group, severe undernutrition increased by 13% (p < 0.04 between groups). In the adjusted covariance analysis, SUPL compared to CON group, increased HGS (Δ 2.8 Kg vs Δ -1.8 Kg, p = 0.003), serum albumin (Δ 0.29 g/dL vs Δ -0.03 g/dL, p = 0.04) and serum transferrin (Δ 4.7 mg/dL vs Δ -0.7 mg/dL, p = 0.0007). The increase in QoL was significantly higher in SUPL group. Dry weight was achieved in 100% of patients in SUPL and 95% in CON group.

CONCLUSIONS

ONS combined with BIVA for dry weight adjustment, improved nutritional status, QoL and achieved dry weight in HD patients.

Adherence to Mediterranean Diet in Individuals on Renal Replacement Therapy

Patients on renal replacement therapy are typically subject to several dietary restrictions; however, this approach has been questioned in recent years, with some suggesting that the Mediterranean diet might be beneficial. Data on the adherence to this diet and factors that influence it are scarce. We conducted a web survey among individuals on renal replacement therapy (dialysis or kidney transplant, KT) using the MEDI-LITE questionnaire to assess adherence to the Mediterranean diet and dietary habits in this population. Adherence to the Mediterranean diet was generally low, and significantly lower among participants on dialysis versus KT recipients (19.4% vs. 44.7%, p < 0.001). Being on dialysis, adopting fluid restrictions, and having a basic level of education were predictors of low adherence to the Mediterranean diet. Consumption of foods typically included in the Mediterranean diet, including fruit, legumes, fish, and vegetables, was generally low, particularly among those on dialysis. There is a need for strategies to improve both the adherence to and the quality of the diet among individuals on renal replacement therapy. This should be a shared responsibility between registered dietitians, physicians, and the patient.

Interdialytic weight gain is not associated with symptoms of depression or apathy in patients on chronic hemodialysis

PURPOSE

Little is known about the relationships between apathy, depressive symptoms and interdialytic weight gain (IDWG) in patients on chronic hemodialysis. Aim of the present study is to investigate the association between IDWG and symptoms of depression and apathy in hemodialysis patients.

METHODS

A total of 139 chronic patients of the HD units between January 2020 and December 2021 were included in the present cross-sectional study. IDWG was calculated as the difference between the pre-HD weight and the weight registered after the previous session; the average of the sessions in a month was registered. Apathy Evaluation Scale (AES) was adopted to evaluate apathy. Depression was assessed by Beck Depression Inventory (BDI).

RESULTS

Ninety-three patients had IDWG% ≤ 4 and 46 had an IDWG% > 4. Correlation between IDWG% and BDI as well that between IDWG% and AES were not statistically significant. Median BDI and mean AES did not differ significantly between the groups. In addition, 104 patients had a BDI < 16 and 35 had a BDI ≥ 6. Seventy-five patients had an AES score ≤ 35 and 63 had a AES score > 35. The IDWG (kg) and the IDWG% did not differ significantly between the two groups.

CONCLUSION

IDWG is not associated with symptoms of depression or apathy in hemodialysis patients. Thus, these results may question if the use of behavioral intervention aimed at improving motivation is warranted in the hemodialysis population to reduce the IDWG.

Assessing Tissue Hydration Dynamics Based on Water/Fat Separated MRI

BACKGROUND

Optimal fluid status is an important issue in hemodialysis. Clinical evaluation of volume status and different diagnostic tools are used to determine hydration status in these patients. However, there is still no accurate method for this assessment.

PURPOSE

To propose and evaluate relative lean water signal (LWS_rel ) as a water-fat MRI-based tissue hydration measurement.

STUDY TYPE

Prospective.

POPULATION

A total of 16 healthy subjects (56 ± 6 years, 0 male) and 11 dialysis patients (60.3 ± 12.3 years, 9 male; dialysis time per week 15 ± 3.5 hours, dialysis duration 31.4 ± 27.9 months).

FIELD STRENGTH/SEQUENCE

A 3 T; 3D spoiled gradient echo.

ASSESSMENT

LWS_rel , a measurement of the water concentration of tissue, was estimated from fat-referenced MR images. Segmentations of total adipose tissue as well as thigh and calf muscles were used to measure LWS_rel and tissue volumes. LWS_rel was compared between healthy subjects and dialysis patients, the latter before and after dialysis. Bioimpedance-based body composition monitor over hydration (BCM OH) was also measured.

STATISTICAL TESTS

T-tests were used to compare differences between the healthy subjects and dialysis patients, as well as changes between before and after dialysis. Pearson correlation was calculated between MRI and non-MRI biomarkers. A P value <0.05 was considered statistically significant.

RESULTS

The LWS_rel in adipose tissue was significantly higher in the dialysis cohort compared with the healthy cohort (246.8% ± 60.0% vs. 100.0% ± 10.8%) and decreased significantly after dialysis (246.8 ± 60.0% vs. 233.8 ± 63.4%). Thigh and calf muscle volumes also significantly decreased by 3.78% ± 1.73% and 2.02% ± 2.50% after dialysis. There was a significant correlation between changes in adipose tissue LWS_rel and ultrafiltration volume (r = 87), as well as with BCM OH (r = 0.66).

DATA CONCLUSION

MRI-based LWS_rel and tissue volume measurements are sensitive to tissue hydration changes occurring during dialysis.

EVIDENCE LEVEL

2.

TECHNICAL EFFICACY

Stage 3.

Nutritional Assessment of Adult Patients Undergoing Maintenance Hemodialysis in the Gaza Strip

Malnutrition is a common condition in patients undergoing hemodialysis (HD), and it is associated with increased morbidity and mortality. The main objective of the study was to evaluate the nutritional status of patients on maintenance HD. After applying eligibility criteria, 141 HD patients attending major governmental dialysis centers were randomly recruited in this cross-sectional study and assessed for nutritional status using the Patient-Generated Subjective Global Assessment (PG-SGA) tool. The PG-SGA categorizes patients as well-nourished, moderately malnourished, and severely malnourished. Different anthropometric measurements, laboratory investigations, blood pressure measurements, and 24-h dietary recall were collected from each patient. According to PG- SGA results, 78% of patients were moderately malnourished and 22% of patients were severely malnourished. The mean body mass index was 27.8 kg/m2, and 5.7% of patients were underweight. There were significant differences in the mid-upper arm muscle circumference (P = 0.020) between the PG-SGA groups. The total energy and protein intake were significantly (P <0.001) less than the recommended dietary intake by 1268.9 kcal and 41.4 g, respectively. The albumin level in 37.6% of patients was less than the normal level, and the results indicated that there were significant differences in serum iron (P = 0.022) between the moderately and severely malnourished patients. The results of this study indicated that all HD patients were suffering from different degrees of malnutrition and, unfortunately, most of their energy and nutrient intake was far less than the requirements, which might be the reason why they face nutritional and health risks.

Nutrition in Conservative Kidney Management: From Evidence to Practice

Conservative kidney management (CKM) is a treatment option for kidney failure, particularly for the elderly and those with co-morbidities. Dietitians can play an important role in the provision of CKM by enhancing patients' quality of life through the management of nutrition impact symptoms (symptoms that result in decreased eating, including anorexia, nausea, dry mouth, and taste changes), as well as symptoms that result from malnutrition, including fatigue, weakness, activity intolerance, slow wound healing, and low mood. There are many gaps in the literature regarding optimal nutritional recommendations for patients on CKM. More research is needed on symptom management and interventions to delay or slow the progression of malnutrition and frailty. This article provides an overview of important nutritional considerations, a synthesis of the current literature, and recommendations for application of evidence into the practice of CKM.

Effects of Mediterranean Diet, DASH Diet, and Plant-Based Diet on Outcomes among End Stage Kidney Disease Patients: A Systematic Review and Meta-Analysis

BACKGROUND

The Mediterranean, Dietary Approach to Stop Hypertension (DASH), and plant-based diets may provide cardiovascular benefit to the general population. However, data on their effect on end stage kidney disease (ESKD) patients are limited. This systematic review aims to assess the impact of Mediterranean, DASH, and plant-based diets on outcomes among ESKD patients.

METHODS

A literature review was conducted in EMBASE, MEDLINE, and Cochrane databases from inception through September 2022 to identify studies that assess the clinical outcomes of Mediterranean, DASH, or plant-based diets on ESKD patients on hemodialysis (HD) or peritoneal dialysis (PD). Effect estimates from the individual studies were derived utilizing the random-effect, generic inverse variance approach of DerSimonian and Laird.

RESULTS

Seven studies with 9400 ESKD patients (8395 HD and 1005 PD) met the eligibility criteria and were included in the data analysis. Pooled odds ratios (ORs) of mortality for ESKD patients who adhered to the Mediterranean versus plant-based diet were 0.49 (95% CI: 0.07-3.54; two studies, I² = 67%) and 0.87 (95% CI: 0.75-1.01; two studies, I² = 0%), respectively. Data on mortality for ESKD patients on a DASH diet were limited to one study with an OR of 1.00 (95% CI: 0.89-1.12). The pooled OR of cardiovascular mortality among ESKD patients who adhered to a plant-based diet was 0.86 (95% CI: 0.68-1.08; two studies, I² = 0%), compared to those who did not. Data on cardiovascular mortality among those with Mediterranean and DASH diet were limited to one study with ORs of 1.14 (95% CI: 0.90-1.43) and 1.19 (95% CI: 0.99-1.43), respectively. Mediterranean diet adherence was found to be associated with reduced risk of left ventricular hypertrophy (LVH) with an OR of 0.82 (95% CI: 0.68-0.99) in a study including 127 ESKD patients. The risk of hyperkalemia was not significant among those with a plant-based diet with an OR of 1.00 (95% CI: 0.94-1.07) in a study including 150 ESKD patients.

CONCLUSIONS

While our systematic review demonstrated no significant associations of Mediterranean, DASH, and plant-based diets with reduced all-cause mortality or cardiovascular mortality, there was also no evidence that suggested harmful effects of these diets to ESKD patients.

Lung Ultrasound Estimates the Overhydration and Benefits Blood Pressure Control in Normal or Mild Symptomatic Hemodialysis Patients

Introduction

Lung ultrasound (LUS) is used for dry weight guidance by assessment of pulmonary congestion in hemodialysis (HD) patients. The aim of this study was to estimate amounts of accumulated fluid by total LUS scores (TLUSS), which were scarcely reported in HD patients who were normal or had a mild functional abnormality. In addition, the correlations between the LUS score of each area and TLUSS were determined to suggest fewer specific areas valuable to shorten the examination time of LUS.

Methods

This cohort study was conducted in adult HD patients who have New York Heart Association Classes I-II. LUS and multifrequency bioimpedance (BIA) were performed at baseline and the individual prescribed dry weight was set. Then each LUS was conducted at 28 areas of bilateral intercostal spaces and calculated as TLUSS weekly for eight weeks in which dry weight was adjusted. The second BIA was also measured at week eight. The difference of pre-HD weight and target weight (weight gain; WG) represented the amount of fluid accumulation.

Results

Twenty patients with a mean age of 62.2±14.0 years were enrolled. One hundred and sixty-six LUS were performed in which forty episodes of them were simultaneously measured with BIA. Optimum dry weight adjusted by TLUSS which benefited in mean reductions of blood pressure, and cardiothoracic ratios. WG amounts were significantly correlated with TLUSS (r=0.38), and with extracellular fluid (r=0.35) and overhydration fluid (r=0.39) assessed by BIA. Estimations of mean fluid overload were 2.18 (TLUSS ≤15), 2.72 (TLUSS 16-24), 3.17 (TLUSS 25-33), 3.65 (TLUSS 34-38) and 5.03 (TLUSS ≥39) in liters. The cut-off points of sum scores of 12 specific lung areas represented the none-mild were <8, moderate at 8-16, and severe pulmonary congestions were >16.

Conclusion

TLUSS estimated accumulated fluid useful for volume and blood pressure controls. Performance of LUS in 12 specific lung areas may reduce spending time and support routine uses of LUS in clinical practice.

Conservative therapy is associated with worse clinical features and biochemical derangements than renal replacement therapy: a retrospective study in Kumasi, Ghana

Background

The incidence of end stage kidney disease (ESKD) is increasing in Ghana as with the rest of the world. This study compared the sociodemographic, diagnostic characteristics (clinical, biochemical and imaging) and clinical outcomes of ESKD patients who chose either renal replacement therapy (RRT) or conservative therapy as well as the factors that influenced their choice.

Methods

We retrospectively reviewed the records of 382 ESKD patient from 2006 to 2018. The data was collected from the Nephrology Clinic at the Komfo Anokye Teaching Hospital (KATH). Sociodemographic, diagnostic (clinical, biochemical and imaging) and therapeutic data were obtained, organized and analyzed with Statistical Package for the Social Sciences (SPSS).

Results

Of the 382 patients, 321 had conservative therapy whiles 61 had renal replacement therapy. The mean age of participants was 47.71 ± 16.10 years. Bipedal swelling (16.8%), fatigue (10.4%) and facial swelling (9.2%) were the major clinical features. Chronic glomerulonephritis (31.4%), hypertension (30.3%) and diabetes mellitus nephropathy (28.2%) were the most frequent predisposing conditions. Nifedipine (82.0%), bisoprolol (32.8%), aspirin (19.7%), ranitidine (26.2%), metformin (13.1%) and lasix (78.7%) were commonly used by the RRT patients than their conservative therapy counterparts. Compared to their RRT counterparts, patients on conservative therapy were more on irbesartan/lisinopril (57.9%) and sodium hydro carbonate (NaHCO₃) (52.0%). Diastolic blood pressure (DBP) (p = 0.047), uremic gastritis (p = 0.007), anaemia, uraemia, haematuria and hyperkalaemia (p < 0.001) were more common in conservative therapy patients than RRT patients with RRT patients showing better corticomedullary differentiation (38.1% vs. 27.7%, p < 0.001) and normal echotexture (15.0% vs. 11.6%, p = 0.005). Age, gender, occupation and duration of illness were significantly associated with the decision to opt for conservative therapy.

Conclusion

Patients on conservative therapy have worse clinical outcomes than their RRT counterparts. Early referrals to nephrologist as well as subsidized RRT should be targeted.

Factors Associated with Long-Term Survival in Maintenance Hemodialysis Patients: A 5-Year Prospective Follow-Up Study

OBJECTIVES

In addition to an increase in the prevalence of dialysis treatments for end-stage renal disease worldwide, the mortality rates among patients on maintenance hemodialysis remain higher than that of the general population. This study aims to evaluate factors associated with long-term survival in stable maintenance hemodialysis patients.

METHODS

A total of 100 patients initiating hemodialysis by February 2013 were included in this prospective cross-sectional 5-year follow-up study. Data on patient demographics, anthropometric-nutritional parameters, systolic and diastolic blood pressure levels, and hemodialysis parameters, including etiology of kidney failure, hemodialysis duration, peritoneal dialysis history, relative interdialytic weight gain (RIDWG), and Kt/V, were recorded.

RESULTS

Overall 5-year survival rate was 56.6%. The 5-year survival rate was higher in patients with younger age (71.4% below median vs. 42.0% above median, p=0.023), lower systolic (63.3 vs. 50%, respectively, p=0.005) and diastolic (62.5 vs. 51.0%, respectively, p=0.02) blood pressure levels, higher Kt/V (46.9 vs. 66.0%, respectively, p=0.044), lower RIDWG (54.0 vs. 32.7%, respectively, p=0.026), and lower serum leptin levels (63.3 vs. 50.0%, respectively, p=0.047). Cox-regression analysis revealed that only systolic blood pressure (B = 1.081, 95% CI, 0.152 to 0.756, p=0.08) was a significant risk factor for poor survival.

CONCLUSION

Our findings revealed pre-dialysis systolic blood pressure as the sole risk factor for poor long-term survival in stable maintenance hemodialysis patients. Malnutrition-inflammation, measures of nutrition, inflammation, and anemia had no significant impact on long-term survival.

Portable sauna stimulated-diaphoresis for the treatment of fluid-overload in peritoneal dialysis patients: A pilot study

Background

Fluid overload (FO) is a common problem in patients with peritoneal dialysis (PD), it is associated with adverse outcomes and may persist despite adjustements in PD therapy.

Objective

To evaluate the feasibility and safety of stimulated diaphoresis to reduce FO with the use of a portable sauna bath.

Methods

Open-label pilot study in patients on continuous ambulatory peritoneal dialysis (CAPD) and FO. The primary outcome was the treatment-related adverse events; secondary outcomes were changes in over-hydration (OH), body weight and blood pressure, FO symptoms, and sleep quality. Dialysis prescription and daily data were recorded. The intervention period consisted in a 30-min, 45°C sauna bath, daily for 10 days, using a portable sauna bath.

Results

Fifty-one out of 54 total sauna bath sessions were well tolerated. In three (5.5%) sessions adverse effects were reported: transient dizziness in two cases, and a second-degree skin burn in a patient with advanced diabetic neuropathy. OH (6.3 ± 1.2 L vs. 5.5 ± 1.3 L, p = 0.05), body weight (67.7 ± 11.4 vs. 66.8 ± 3.8 kg, p = 0.003), diastolic blood pressure (92 ± 13.5 vs. 83 ± 13.3 mmHg, P = 0.003) and PSQI score (7.3 ± 3.7 vs. 5.1 ± 3.2, p = 0.02) improved significantly between the control and intervention period, respectively.

Conclusions

Stimulated diaphoresis with a portable sauna bath could be a novel, safe, and effective alternative way to reduce FO in CAPD patients. Larger studies are needed to confirm our results.

Clinical trial registration

ClinicalTrials.gov, identifier: NCT03563898.

High Inferior Vena Cava Diameter with High Left Ventricular End Systolic Diameter as a Risk Factor for Major Adverse Cardiovascular Events, Cardiovascular and Overall Mortality among Chronic Hemodialysis Patients

Background: Little is known about the association of inferior vena cava diameter (IVCD) and left ventricular end-systolic diameter (LVESD) with mortality in patients undergoing hemodialysis (HD). Methods: The single medical center observational cohort study enrolled 241 adult chronic HD patients from 1 October 2018 to 31 December 2018. Echocardiography results of IVCD and LVESD prior to dialysis were retrieved and patients were divided into high IVCD and low IVCD groups. Patients who received HD via a tunneled cuffed catheter were excluded. Study outcomes included all-cause mortality, cardiovascular mortality, and major adverse cardiovascular events (MACE). Subgroup analyses of HD patients with high and low LVESD were also performed. Results: The incidence of all-cause mortality, cardiovascular mortality, and MACE were higher in chronic HD patients with high IVCD (p < 0.01). High IVCD patients had significantly greater all-cause mortality, cardiovascular mortality, and MACE (log-rank test; p < 0.05). High IVCD patients are also associated with an increased risk of all-cause mortality and MACE relative to low IVCD patients (aHRs, 2.88 and 3.42; 95% CIs, 1.06−7.86 and 1.73−6.77, respectively; all p < 0.05). In the subgroup analysis of patients with high or low LVESD, the high IVCD remained a significant risk factor for all-cause mortality and MACE, and the HR is especially high in the high LVESD group. Conclusions: Dilated IVCD is a risk factor for all-cause mortality and MACE in chronic HD patients. In addition, these patients with high LVESD also have a significantly higher HR of all-cause mortality and MACE.

A first proof-of-concept for the non-invasive, time-efficient measurement of the plasma sodium concentration for individualized dialysis

Dialysis-induced changes in plasma sodium concentration may cause undesirable side effects. To prevent these, the sodium content in dialysis fluid has to be individualized based on the patient's plasma sodium concentration. In this paper, we describe a simple conductivity based method for measuring the plasma sodium concentration. The method is based on performing a bypass during which the residual volume on the dialysate side of the dialyzer at least partially adopts the sodium concentration on the blood side. The conductivity at dialysate outlet of the dialyzer after the end of bypass corresponds to the sodium concentration. We show that already 14 s of bypass are sufficient to subsequently measure a conductivity that correlates with the blood-side sodium concentration. Thus, the short bypass method allows a time saving of 88% compared to the long bypass of 120 s. In vitro experiments with bovine blood show that plasma sodium concentration can be non-invasively and time-efficiently measured during dialysis. Bland Altman analysis reveals a bias of 0.28 mmol/l and limits of agreement of -3.17 and 3.74 mmol/l for the long bypass. For the short bypass, bias is 0.09 mmol/l and limits are -3.90 and 4.08 mmol/l. Since the method presented is based on established conductivity cells, no additional sensors are required, so that the method could be easily implemented in dialysis machines. In future, performing a bypass at the beginning of a treatment may be used to adjust the composition of dialysis fluid individually for each patient.

Executive summary of the Korean Society of Nephrology 2021 clinical practice guideline for optimal hemodialysis treatment

The Korean Society of Nephrology (KSN) has published a clinical practice guideline (CPG) document for maintenance hemodialysis (HD). The document, 2021 Clinical Practice Guideline on Optimal HD Treatment, is based on an extensive evidence-oriented review of the benefits of preparation, initiation, and maintenance therapy for HD, with the participation of representative experts from the KSN under the methodologists' support for guideline development. It was intended to help clinicians participating in HD treatment make safer and more effective clinical decisions by providing user-friendly guidelines. We hope that this CPG will be meaningful as a recommendation in practice, but not on a regulatory rule basis, as different approaches and treatments may be used by health care providers depending on the individual patient's condition. This CPG consists of eight sections and 15 key questions. Each begins with statements that are graded by the strength of recommendations and quality of the evidence. Each statement is followed by a summary of the evidence supporting the recommendations. There are also a link to full-text documents and lists of the most important reports so that the readers can read further (most of this is available online).

Acute Water Supplementation Improved the Body Composition of Young Female Adults After Water Restriction of 12 h in Baoding, China: A Randomized Controlled Trial (RCT)

Insufficient intake of water may influence the balance of water in the human body. In this study, we explore the impacts of water supplementation on body composition indices among young adults after 12 h of water restriction, with the aim to determine the optimum volume of water for improving body water composition. A randomized controlled trial study was conducted among 64 young men and women in Baoding, China. After fasting overnight for 12 h, anthropometric measurements and urine and blood samples were collected as a baseline test at 8:00 a.m. of Day 2. Body composition was determined by measuring the ECW (extracellular water), ICW (intracellular water), and TBW (total body water) through bioelectrical impedance analysis (BIA). The participants were randomly divided into four groups, including water supplementation (WS) groups 1, 2, and 3, with 500, 200, and 100 mL of water, respectively, and a no water supplementation (NW) group. After 90 min, they were reassessed in a rehydration test (at 10:00 a.m. of Day 2). Repeated measurement ANOVA was used to assess the impact of water supplementation on body composition. Comparing the baseline and rehydration tests, interactions between time and volume were not significant among the men (all p > 0.05). Among women, a significant interaction was only found in ECW (p = 0.043), with TBW tending toward being significant (p = 0.055). Comparing the baseline and rehydration tests, the ECW in WS group 1, WS group 3, and the NW group all decreased (p = 0.028, p = 0.001, and p = 0.029), with reductions of 0.1, 0.3, and 0.2 kg, respectively; however, no significant decrease was observed in WS group 2 (p = 0.329). Furthermore, comparing the WS groups with the NW group in the rehydration test, the differences were not significant (p = 1.000, p = 1.000, and p = 0.288, respectively). Between men and women within groups, all of the body composition indices differed significantly, both at baseline and rehydration tests (all p < 0.05). Water supplementation led to changes in the distribution of the water content in young female adults in this study-but not men-after 12 h of water restriction, with no decrease in ECW. Finally, we found that 200 mL was the minimum volume capable of improving the water content distribution in participants in this study.

Trial Registration

[www.chictr.org.cn], identifier [ChiCTR-IOR-17011568].

Dynamics of Cardiac Autonomic Responses During Hemodialysis Measured by Heart Rate Variability and Skin Sympathetic Nerve Activity: The Impact of Interdialytic Weight Gain

Background: Autonomic nervous regulation plays a critical role in end-stage kidney disease (ESKD) patients with cardiovascular complications. However, studies on autonomic regulation in ESKD patients are limited to heart rate variability (HRV) analysis. Skin sympathetic nerve activity (SKNA), which noninvasively reflects the sympathetic nerve activity, has not been used in ESKD patients.

Methods: Seventy-six patients on maintenance hemodialysis (MHD) treatment (a 4-h HD session, three times a week) were enrolled. Utilizing a noninvasive, single-lead, high-frequency recording system, we analyzed the dynamic change in HRV parameters and SKNA during HD. The different characteristics between the subgroups divided based on interdialytic weight gain (IDWG, &lt;3 kg or ≥3 kg) were also demonstrated.

Results: After the HD, values for heart rate (75.1 ± 11.3 to 80.3 ± 12.3 bpm, p &lt; 0.001) and LF/HF (1.92 ± 1.67 to 2.18 ± 2.17, p = 0.013) were significantly higher than baseline. In subgroup analysis, average voltage of skin sympathetic nerve activity (aSKNA) in IDWG ≥3 kg group was lower than the IDWG &lt;3 kg group at the end of MHD (1.06 ± 0.30 vs 1.32 ± 0.61 μV, p = 0.046). Moreover, there was a linear correlation between mean heart rate (HR) and aSKNA in low IDWG patients (p &lt; 0.001), which was not found in high IDWG patients. At the 1-year follow-up, high IDWG patients had a higher incidence of cardiovascular hospitalization (p = 0.046).

Conclusions: In MHD patients, a gradual activation of sympathetic nerve activity could be measured by HRV and aSKNA. A lower aSKNA at the end of HD and a loss of HR-aSKNA correlation in overhydrated patients were observed. Extensive volume control is promising to improve the autonomic nervous function and clinical outcomes in this population.

The Extracellular Mass to Body Cell Mass Ratio as a Predictor of Mortality Risk in Hemodialysis Patients

The extracellular mass/body cell mass ratio (ECM/BCM ratio) is a novel indicator of nutritional and hydration status in hemodialysis (HD) patients. This study aimed to explore the ECM/BCM ratio as a predictor of mortality risk with nutritional-inflammatory markers in HD patients. A prospective observational study was conducted in 90 HD patients (male: 52.2%; DM: 25.60%). Clinical and biochemical parameters [serum albumin, serum C-reactive protein (s-CRP), interleukine-6 (IL-6)] were analysed and bioelectrical impedance analysis (BIA) was performed. Protein-energy wasting syndrome (PEW) was diagnosed using malnutrition-inflammation score (MIS). Based on BIA-derived measurements, the ECM/BCM ratio with a cut-off point of 1.20 was used as a PEW-fluid overload indicator. Comorbidity by Charlson index and hospital admissions were measured. Out of 90 HD patients followed up for 36 months, 20 patients (22.22%) died. PEW was observed in 24 survivors (34.28%) and all non-survivors. The ECM/BCM ratio was directly correlated with MIS, s-CRP, Charlson index and hospital admissions but was negatively correlated with phase angle and s-albumin (all, p < 0.001). Values of the ECM/BCM ratio ≥ 1.20 were associated with higher probability of all-cause mortality (p = 0.002). The ECM/BCM ratio ≥ 1.20, IL-6 ≥ 3.1 pg/mL, s-CRP and s-albumin ≥ 3.8 g/dL and Charlson index were significantly associated with all-cause mortality risk in multivariate adjusted analysis. This study demonstrates that the ECM/BCM ratio ≥ 1.20 as a nutritional marker and/or fluid overload indicator had a significant prognostic value of death risk in HD patients.

Factors associated with aortic valve stenosis in Japanese patients with end-stage kidney disease

Background

Aortic valve stenosis (AS) has a high prevalence and poor prognosis in patients who receive maintenance dialysis. However, few large-scale observational studies in Japan have investigated patients with AS who underwent dialysis. In this study, we investigated the prevalence and factors associated with AS in Japanese patients who underwent dialysis.

Methods

In this cross-sectional analysis, we enrolled patients who underwent dialysis and transthoracic echocardiography between July 1, 2017 and June 30, 2018. Patients with a maximum aortic jet velocity (Vmax) ≥ 2.0 m/s, pressure gradient (PG) between the left ventricle and ascending aorta (mean PG) ≥ 20 mmHg, or aortic valve area (AVA) ≤ 1.0 cm² were categorized into the AS group (G1). Patients with Vmax ≥ 3.0 m/s, mean PG ≥ 20 mmHg, or AVA ≤ 1.0 cm² were categorized into the moderate and severe AS groups (G2). We performed multivariate logistic regression analysis and compared G1 and G2 with the non-AS group to determine the risk factors for AS. We also investigated the risk factors for aortic valve calcification, which is a pre-stage for AS.

Results

Of the 2,786 patients investigated, 555 (20.0%) and 193 (6.9%) were categorized into G1 and G2, respectively. Multivariate logistic regression analysis revealed that age, long-term dialysis, and elevated serum phosphorus levels were associated with AS in both the groups (p < 0.05). These factors were converted into ordinal categories, and a multivariate logistic regression analysis was performed. Patients with serum phosphorus levels measuring 5.0–5.9 mg/dL and > 6.0 mg/dL showed a higher risk of AS than those with serum phosphorus levels measuring < 4.0 mg/dL (odds ratio 2.24, p = 0.01 and odds ratio 2.66, p = 0.005, respectively). Aortic valve calcification was associated with age, long-term dialysis, diabetes mellitus, administration of vitamin D receptor activators, elevated serum calcium levels, and anemia (p < 0.05 for all).

Conclusions

Patients on dialysis showed a high prevalence of AS, which was associated with age, long-term dialysis, and elevated serum phosphorus levels.

Trial registration

UMIN000026756, registered on March 29, 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02758-y.

Assessing proximate intermediates between ambient temperature, hospital admissions, and mortality in hemodialysis patients

BACKGROUND

Typical thermoregulatory responses to elevated temperatures among healthy individuals include reduced blood pressure and perspiration. Individuals with end-stage kidney disease (ESKD) are susceptible to systemic fluctuations caused by ambient temperature changes that may increase morbidity and mortality. We investigated whether pre-dialysis systolic blood pressure (preSBP) and interdialytic weight gain (IDWG) can independently mediate the association between ambient temperature, all-cause hospital admissions (ACHA), and all-cause mortality (ACM).

METHODS

The study population consisted of ESKD patients receiving hemodialysis treatments at Fresenius Medical Care facilities in Philadelphia County, PA, from 2011 to 2019 (n = 1981). Within a time-to-event framework, we estimated the association between daily maximum dry-bulb temperature (TMAX) and, as separate models, ACHA and ACM during warmer calendar months. Clinically measured preSBP and IDWG responses to temperature increases were estimated using linear mixed effect models. We employed the difference (c-c') method to decompose total effect models for ACHA and ACM using preSBP and IDWG as time-dependent mediators. Covariate adjustments for exposure-mediator and total and direct effect models include age, race, ethnicity, blood pressure medication use, treatment location, preSBP, and IDWG. We considered lags up to two days for exposure and 1-day lag for mediator variables (Lag 2-Lag 1) to assure temporality between exposure-outcome models. Sensitivity analyses for 2-day (Lag 2-only) and 1-day (Lag 1-only) lag structures were also conducted.

RESULTS

Based on Lag 2- Lag 1 temporal ordering, 1 °C increase in daily TMAX was associated with increased hazard of ACHA by 1.4% (adjusted hazard ratio (HR), 1.014; 95% confidence interval, 1.007-1.021) and ACM 7.5% (adjusted HR, 1.075, 1.050-1.100). Short-term lag exposures to 1 °C increase in temperature predicted mean reductions in IDWG and preSBP by 0.013-0.015% and 0.168-0.229 mmHg, respectively. Mediation analysis for ACHA identified significant indirect effects for all three studied pathways (preSBP, IDWG, and preSBP + IDWG) and significant indirect effects for IDWG and conjoined preSBP + IDWG pathways for ACM. Of note, only 1.03% of the association between temperature and ACM was mediated through preSBP. The mechanistic path for IDWG, independent of preSBP, demonstrated inconsistent mediation and, consequently, potential suppression effects in ACHA (-15.5%) and ACM (-6.3%) based on combined pathway models. Proportion mediated estimates from preSBP + IDWG pathways achieved 2.2% and 0.3% in combined pathway analysis for ACHA and ACM outcomes, respectively. Lag 2 discrete-time ACM mediation models exhibited consistent mediation for all three pathways suggesting that 2-day lag in IDWG and preSBP responses can explain 2.11% and 4.41% of total effect association between temperature and mortality, respectively.

CONCLUSION

We corroborated the previously reported association between ambient temperature, ACHA and ACM. Our results foster the understanding of potential physiological linkages that may explain or suppress temperature-driven hospital admissions and mortality risks. Of note, concomitant changes in preSBP and IDWG may have little intermediary effect when analyzed in combined pathway models. These findings advance our assessment of candidate interventions to reduce the impact of outdoor temperature change on ESKD patients.

Clinical Significance of Volume Status in Body Composition and Physical Performance Measurements in Hemodialysis Patients

Introduction

This study aimed to evaluate the association between volume status and body composition or physical performance measurements in hemodialysis patients.

Methods

A total of 84 patients were enrolled in this study. The participants were divided into tertiles based on the edema index (extracellular water/total body water): low, middle, and high tertiles. Serum albumin and serum high-sensitivity C-reactive protein levels were measured. The appendicular lean mass index (ALM/Ht², kg/m²) was measured using dual-energy X-ray absorptiometry. The thigh muscle area index (TMA/Ht², cm²/m²) was measured using CT. Extracellular and total body water and phase angles were obtained using bioimpedance analysis. The results of the subjective global assessment (SGA), hand-grip strength (HGS), gait speed (GS), short physical performance battery (SPPB), sit-to-stand for 30-second (STS30) test, timed up and go (TUG), sit-to-stand test performed five times (STS5), and 6-minute walk (6-MW) tests were also evaluated.

Results

On the univariate analysis, the SGA score and phase angle in the high tertile group were the lowest among the three groups. On multivariate analysis, TMA/Ht² and phase angle in the high tertile were the lowest among the three groups. Inverse correlations were observed between edema index and TMA/Ht², SGA score, phase angle, HGS, GS, SPPB, STS30, or 6-MW. Positive correlations were observed between the edema index and the STS5 or TUG test. The sensitivity and specificity for predicting low GS were 34.5 and 89.7%, respectively. The values for predicting low SPPB were 68.0 and 79.7%, respectively.

Conclusion

This study demonstrates that high volume status may be associated with decreased muscle mass and physical performance regardless of inflammatory or nutritional status.

Inter- and intradialytic fluid volume changes and vascular stiffness parameters in patients on hemodialysis

BACKGROUND

Whether fluid overload is associated with vascular stiffness parameters in hemodialysis (HD) patients has not been fully elucidated. We hypothesized that interdialytic fluid accumulation increases vascular stiffness parameters, which improves with intradialytic ultrafiltration.

METHODS

Fluid overload and vascular stiffness parameters were assessed in 39 HD patients (20 with and 19 without fluid overload) and compared to 26 healthy controls. Fluid status was assessed 15 minutes before the mid-week HD session by bio-impedance spectroscopy. Following this, ambulatory pulse wave velocity (PWV) and augmentation index (AIx) were measured for 24 hours before another mid-week HD session and then for 5 hours starting 30 minutes before and ending 30 minutes after the session.

RESULTS

HD patients had significant fluid overload compared to healthy controls (2.0±2.4 vs. -0.2±0.6 L; P<0.001) and baseline PWV was higher (10.3±1.7 vs. 8.8±1.4 m/s; P<0.001). There was no significant difference between PWV and AIx in fluid overloaded and non-fluid overloaded HD patients prior to, or during the HD session. AIx of non-fluid overloaded HD patients improved after the HD session (P = 0.04). Average 24-hour AIx was higher in fluid overloaded HD patients (P<0.001).

CONCLUSIONS

Inter- and intradialytic changes in fluid volume were only weakly related to vascular stiffness parameters in HD patients. Although there was a modest reduction in AIx in non-fluid overloaded HD patients after the dialysis session, fluid removal did not improve vascular stiffness parameters during the HD session. We speculate that the effect of fluid overload correction on vascular stiffness parameters requires long-term adjustments in the vasculature.

Protocol of a pilot-scale, single-arm, observational study to assess the utility and acceptability of a wearable hydration monitor in haemodialysis patients

Background

Fluid overload has a high prevalence in haemodialysis patients and is an important risk factor for excess mortality and hospitalisations. Despite the risks associated with chronic fluid overload, it is clinically difficult to assess and maintain fluid status adequately. Current methods of fluid status assessment are either imprecise or time intensive. In particular, to date, no method exists to accurately assess fluid status during the interdialytic interval.

Objectives

This pilot study aimed to evaluate whether a prototype wearable hydration monitor can accurately and reproducibly detect fluid overload in the haemodialysis population when compared to haemodialysis and bioimpedance data.

Methods

A prospective, open-label, single-arm observational trial of 20 patients commenced in January 2021 in a single haemodialysis centre in Ireland, with a wearable hydration monitor, the Sixty device. The Sixty device uses diffuse reflectance spectroscopy to measure fluid levels at the level of the subdermis and uses machine learning to develop an algorithm that can determine fluid status. The Sixty device was worn at every dialysis session and nocturnally over a three-week observational period. Haemodialysis parameters including interdialytic weight gain, ultrafiltration volume, blood pressure, and relative blood volume were collected from each session, and bioimpedance measurements using the Fresenius body composition monitor were performed on 4 occasions as a comparator. The primary objective of this trial was to determine the accuracy and reproducibility of the Sixty device compared to bioimpedance measurements.

Conclusion

If the accuracy of the wearable hydration monitor is validated, further studies will be conducted to integrate the device output into a multi-parameter machine learning algorithm that can provide patients with actionable insights to manage fluid overload in the interdialytic period.

Trial registration

www.clinicaltrials.govNCT04623281. Registered November 10th, 2020.

Patient-centred approaches for the management of unpleasant symptoms in kidney disease

Patients with chronic kidney disease (CKD) frequently experience unpleasant symptoms. These can be gastrointestinal (constipation, nausea, vomiting and diarrhoea), psychological (anxiety and sadness), neurological (lightheadedness, headache and numbness), cardiopulmonary (shortness of breath and oedema), dermatological (pruritus and dry skin), painful (muscle cramps, chest pain and abdominal pain) or involve sexual dysfunction, sleep disorders and fatigue. These symptoms often occur in clusters, with one of them as the lead symptom and others as secondary symptoms. Uraemic toxins (also called uremic toxins) are often considered to be the main cause of CKD-associated symptom burden, but treatment of uraemia by dialysis often fails to resolve them and can engender additional symptoms. Indeed, symptoms can be exacerbated by comorbid conditions, pharmacotherapies, lifestyle and dietary regimens, kidney replacement therapy and ageing. Patients with kidney disease, including those who depend on dialysis or transplantation, should feel actively supported in their symptom management through the identification and targeting of unpleasant symptoms via a tailored palliative care approach. Such an approach may help minimize the burden and consequences of kidney disease, and lead to improved patient outcomes including health-related quality of life and better life participation.

Excessive fluid volume risk middle-range theory

ABSTRACT Objective to construct a middle range theory for developing the excessive fluid volume risk diagnostic proposition in patients undergoing hemodialysis. Method this is a methodological study, developed for the theoretical-causal validity of a nursing diagnosis. The study was carried out in four stages: study selection, identification of the main concepts of the theory, pictogram construction and proposition elaboration. These steps were operationalized through an integrative literature review, with a sample of 82 articles selected from the Web of Science, PubMed, CINAHL, Scopus and Science Direct databases. Results the data extracted from the sample articles enabled identifying five essential terms to define excessive fluid volume risk. Furthermore, 31 etiological factors of excessive fluid volume risk were identified, in addition to a pictogram and 12 propositions. Conclusion and implications for practice the construction of a middle-range theory focused on excessive fluid volume risk in patients undergoing hemodialysis refines terminology and expands the understanding of nursing phenomena. Thus, the data from this research will provide clear and robust knowledge for the conduct of nurses’ actions in clinical practice.