Intradialytic hypotension, blood pressure changes and mortality risk in incident hemodialysis patients

External validation of the prediction model of intradialytic hypotension: a multicenter prospective cohort study

OBJECTIVE

Intradialytic hypotension (IDH) is a common and serious complication in patients with Maintenance Hemodialysis (MHD). The purpose of this study is to externally verify three IDH risk prediction models recently developed by Ma et al. and recalibrate, update and present the optimal model to improve the accuracy and applicability of the model in clinical environment.

METHODS

A multicenter prospective cohort study of patients from 11 hemodialysis centers in Sichuan Province, China, was conducted using convenience sampling from March 2022 to July 2022, with a follow-up period of 1 month. Model performance was assessed by: (1) Discrimination: Evaluated through the computation of the Area Under Curve (AUC) and its corresponding 95% confidence intervals. (2) Calibration: scrutinized through visual inspection of the calibration plot and utilization of the Brier score. (3) The incremental value of risk prediction and the utility of updating the model were gauged using NRI (Net Reclassification Improvement) and IDI (Integrated Discrimination Improvement). Decision Curve Analysis (DCA) was employed to evaluate the clinical benefit of updating the model.

RESULTS

The final cohort comprised 2235 individuals undergoing maintenance hemodialysis, exhibiting a 14.6% occurrence rate of IDH. The externally validated Area Under the Curve (AUC) values for the three original prediction models were 0.746 (95% CI: 0.718 to 0.775), 0.709 (95% CI: 0.679 to 0.739), and 0.735 (95% CI: 0.706 to 0.764) respectively. Conversely, the AUC value for the recalibrated and updated columnar plot model reached 0.817 (95% CI: 0.791 to 0.842), accompanied by a Brier score of 0.081. Furthermore, Decision Curve Analysis (DCA) exhibited a net benefit within the threshold probability range of 15.2% to 87.1%.

CONCLUSION

Externally validated, recalibrated, updated, and presented IDH prediction models may serve as a valuable instrument for evaluating IDH risk in clinical practice. Furthermore, they hold the potential to guide clinical providers in discerning individuals at risk and facilitating judicious clinical intervention decisions.

The effect of changes in intra-compartmental bioimpedance measurements with early intra-dialytic hypotension during haemodialysis

INTRODUCTION

Intra-dialytic hypotension (IDH) remains the commonest problem associated with routine haemodialysis treatments. Fluid shifts from intracellular(ICW) and extracellular(ECW) compartments to refill plasma volume during haemodialysis with ultrafiltration.

METHODS

We studied the effect of relative changes in ICW and ECW indifferent body segments using multifrequency segmental bioimpedance during haemodialysis and IDH episodes.

RESULTS

Of 42 haemodialysis patients,16 patients (38.1%) developed IDH within the first hour of dialysis. Patients with and without early IDH were well-matched for demographics and starting bioimpedance measurements. However, after 60 min, the relative change in in ECW/ICW ratio between the non-fistula arm and leg was significantly different for the early IDH group median -1.07 (-3.33 to 0.8) versus 0.61 (-0.78 to 1.8), p < 0.05, whereas there no differences in ultrafiltration rate, relative blood volume monitoring or on-line clearance.

CONCLUSION

Monitoring serial changes in fluid status in different body compartments with bioimpedance may potentially prevent IDH in the future.

Reliability and benefit of estimated continuous cardiac output measurement using shunt-side SpO2 monitor in hemodialysis

INTRODUCTION

Estimated continuous cardiac output (esCCO) is a novel technology that enables non-invasive and continuous monitoring of cardiac output. We compared the concordance in accuracies among esCCO measurements in the shunt limb and non-shunt limb.

METHODS

In this single-center prospective observational study, we include Japanese patients who underwent dialysis at our center between April 27, 2021, and February 28, 2023. Clinical accuracy of esCCO was evaluated in the shunted and non-shunted bilateral digits. Agreement between the measurements was analyzed using Lin's congruent correlation and Bland-Altman analysis.

RESULTS

For 43 individuals, Lin's concordance correlation coefficient was 0.9887 (95% confidence interval of 0.9886-0.9887) indicating good agreement. The values of esCCO measured in the shunt and non-shunt limbs were compatible. The percentage errors for the 43 patients with arterio-venous fistula (AVF) or arterio-venous graft (AVG), 32 with AVF, and 11 with AVG were 9.3%, 9.3%, and 8.9%, respectively.

CONCLUSION

esCCO could be used in shunt as well as non-shunt limbs during dialysis, allowing continuous and non-invasive hemodynamic monitoring.

The effect of different dialysate sodium concentrations on ambulatory blood pressure in hemodialysis patients: a prospective interventional study

Background

Hypertension is associated with increased morbidity and mortality in hemodialysis patients. Existing recommendations suggest reduction of sodium load, but the effect of dialysate sodium on blood pressure (BP) is not fully elucidated. The aim of the present study is to investigate the effect of different dialysate sodium concentrations on 72-h ambulatory BP in hemodialysis patients.

Methods

This prospective study included patients on standard thrice-weekly hemodialysis. All patients initially underwent six sessions with dialysate sodium concentration of 137 meq/L, followed consecutively by another six sessions with dialysate sodium of 139 meq/L and, finally, six sessions with dialysate sodium of 141 meq/L. At the start of the sixth hemodialysis session on each sodium concentration, 72-h ABPM was performed over the long interdialytic interval to evaluate ambulatory systolic and diastolic BP (SBP and DBP) during the overall 72-h, different 24-h, daytime and night-time periods.

Results

Twenty-five patients were included in the final analysis. A significant increase in the mean 72-h SBP was observed with higher dialysate sodium concentrations (124.8 ± 16.6 mmHg with 137 meq/L vs 126.3 ± 17.5 mmHg with 139 meq/L vs 132.3 ± 19.31 mmHg with 141 meq/L, P = 0.002). Similar differences were noted for DBP; 72-h DBP was significantly higher with increasing dialysate sodium concentrations (75.1 ± 11.3 mmHg with 137 meq/L vs 76.3 ± 13.7 mmHg with 139 meq/L vs 79.5 ± 13.9 mmHg with 141 meq/L dialysate sodium, P = 0.01). Ambulatory BP during the different 24-h intervals, daytime and night-time periods was also progressively increasing with increasing dialysate sodium concentration.

Conclusion

This pilot study showed a progressive increase in ambulatory BP with higher dialysate sodium concentrations. These findings support that lower dialysate sodium concentration may help towards better BP control in hemodialysis patients.

Changes in Cardiac Structure and Function of Recipients after Kidney Transplantation

Background: Chronic kidney disease (CKD) elevates the risk of cardiovascular disease (CVD) and mortality. Uremic cardiomyopathy, frequently observed in CKD and end-stage renal disease (ESRD), involves alterations in cardiac structure and function, which may reverse post-kidney transplantation, although data remain controversial. This study examines the relationship between graft function and changes in cardiac parameters pre- and post-transplantation in kidney transplant recipients. Methods: A total of 145 pediatric and adult recipients of living or deceased donor kidney transplants were enrolled at Gazi Yaşargil Training and Research Hospital. This cohort study utilized transthoracic echocardiographic (TTE) imaging pre-transplant and at least two years post-transplant. Echocardiographic parameters were analyzed using standard techniques. Results: The mean age of the participants was 35 years, with 60% male. The average dialysis duration prior to transplantation was 27 months. Most recipients (83.4%) received kidneys from living donors. Left ventricular diastolic dysfunction increased significantly post-transplant (p < 0.05), while other cardiac dimensions and functions, such as ejection fraction and pulmonary artery pressure, showed no significant change (p > 0.05). Notably, diastolic dysfunction worsened in patients with dysfunctional grafts (GFR < 45), correlating with increased pulmonary artery pressure post-transplant. The rate of antihypertensive drug use and the prevalence of diabetes mellitus increased significantly post-transplant (p < 0.05). Conclusions: This study demonstrates that left ventricular diastolic dysfunction present before kidney transplantation continues to persist post-transplantation in patients with end-stage renal disease undergoing chronic kidney disease treatment. Furthermore, it shows an increased rate of pulmonary artery pressure and pericardial effusion in patients with dysfunctional grafts after transplantation. Further research is required to explore strategies to reverse uremic cardiomyopathy and reduce cardiovascular risk in these patients.

Usefulness of the heart rate variability test in predicting intradialytic hypotension in patients undergoing chronic haemodialysis

Background

Intradialytic hypotension (IDH) is the primary complication of haemodialysis (HD); however, its diverse pathophysiology and inconsistent definitions complicate its prediction. Despite attempts using the heart rate variability (HRV) test for IDH prediction, studies on its usefulness for predicting IDH diagnosed per the nadir 90 criterion are lacking. We aimed to evaluate HRV test efficacy and reproducibility in predicting IDH based on the nadir 90 criterion.

Methods

Seventy patients undergoing HD participated in this multicentre prospective observational study. The HRV test was performed during non-HD periods and IDH was monitored during 12 HD sessions. IDH was diagnosed according to the nadir 90 criterion, defined as a decrease in systolic blood pressure of ≤90 mmHg during HD. After monitoring, the HRV test was repeated. An HRV-IDH index was developed using multivariate logistic regression analysis employing HRV test parameters. The predictive power of the HRV-IDH index was analysed using the area under the receiver operating characteristics curve (AUROC). Reproducibility was evaluated using correlation analysis of two HRV tests on the same patient.

Results

There were 37 and 33 patients in the IDH and non-IDH groups, respectively. The HRV-IDH index predicted IDH occurrence with AUROCs of 0.776 and 0.803 for patients who had experienced at least one or repeated IDH episodes, respectively. Spearman's correlation coefficient for HRV-IDH indices was 0.859 for the first and second HRV tests.

Conclusions

The HRV test holds promise for predicting IDH, particularly for patients with recurring IDH diagnosed based on the nadir 90 criterion.

Left ventricular remodeling and its correlation with serum cardiac troponin I in patients with end-stage renal disease treated

OBJECTIVE

To investigate the effects of different blood purification modes on left ventricular remodeling and its relationship with serum cardiac troponin I (cTnI) in patients with end-stage renal disease (ESRD).

METHOD

A total of 108 patients with ESRD were selected, 55 cases were divided into hemodialysis combined with hemoperfusion (HD + HP) group, in which patients participants accepted routine hemodialysis for three times/week and hemoperfusion for three times/month; 53 cases in hemodialysis combined with hemodialysis filtration (HD + HDF) group, routine hemodialysis three times/week + hemodialysis filtration three times/month. The total duration of dialysis in the study was 1 year. Cardiac troponin I (cTnI) levels were measured before dialysis and 1 year after treatment, and related parameters were measured by echocardiography, including ventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT), left ventricular end diastolic diameter (LVEDd), left ventricular end systolic diameter (LVEDs), and left ventricular myocardial mass index (LVMI). The paired t test was used within the group. Correlation analysis was performed using Spearman correlation analysis.

RESULT

After treatment, the levels of cTnI, IVST, LVPWT, LVEDd, LVEDs, and LVMI in the two groups were increased, and the results were statistically significant (all p < 0.05). In addition, cTnI of the two groups was significantly correlated with IVST, LVPWT, LVEDd, LVEDs, and LVMI (all p < 0.05).

CONCLUSION

Left ventricular remodeling is common in patients with ESRD, HD + Hp, and HD + HDF cannot reduce the phenomenon of left ventricular remodeling, cTnI can be used as a predictor of left ventricular hypertrophy and enlargement.

Continuous Monitoring of Advanced Hemodynamic Parameters during Hemodialysis Demonstrated Early Variations in Patients Experiencing Intradialytic Hypotension

Intradialytic hypotension (IDH) is a severe complication of hemodialysis (HD) with a significant impact on morbidity and mortality. In this study, we used a wearable device for the continuous monitoring of hemodynamic vitals to detect hemodynamic changes during HD and attempted to identify IDH. End-stage kidney disease patients were continuously monitored 15 min before starting the session and until 15 min after completion of the session, measuring heart rate (HR), noninvasive cuffless systolic and diastolic blood pressure (SBP and DBP), stroke volume (SV), cardiac output (CO), and systemic vascular resistance (SVR). Data were analyzed retrospectively and included comparing BP measured by the wearable devices (recorded continuously every 5 s) and the cuff-based devices. A total of 98 dialysis sessions were included in the final analysis, and IDH was identified in 22 sessions (22.5%). Both SBP and DBP were highly correlated (r > 0.62, p < 0.001 for all) between the wearable device and the cuff-based measurements. Based on the continuous monitoring, patients with IDH had earlier and more profound reductions in SBP and DBP during the HD treatment. In addition, nearly all of the advanced vitals differed between groups. Further studies should be conducted in order to fully understand the potential of noninvasive advanced continuous monitoring in the prediction and prevention of IDH events.

Hypertensive Emergency During Dialysis: A Paradoxical Physiologic Response

Most end-stage renal disease patients experience a reduction in blood pressure during their hemodialysis session compared to predialysis. Surprisingly, a small subset of patients will experience an unusual physiological response to dialysis that results in a paradoxical increase in blood pressure. We discuss a case that involved an exaggerated elevation in blood pressure, ultimately requiring immediate cessation of dialysis and admission to the intensive care unit for intravenous treatment of a hypertensive emergency. This case serves as a framework to introduce the infrequently discussed concept of intradialytic hypertension. The underlying pathogenesis is poorly understood with multiple theoretical etiologies including activation of the renin-angiotensin-aldosterone system, imbalances in circulating levels of endothelium-derived mediators, clearance of antihypertensive medications, increased cardiac output, and changes in arterial thickness. It is important to be cognizant of this phenomenon as emerging evidence suggests that patients with any elevation in blood pressure during hemodialysis have increased rates of both short-term and long-term mortality.

Higher NT-proBNP levels and the risk of intradialytic hypotension at hemodialysis initiation

INTRODUCTION

Elevated N-terminal pro B-type natriuretic peptide (NT-proBNP) is a potent predictor of adverse outcomes in hemodialysis initiation. These patients often experience intradialytic hypotension, which may partially reflect cardiac dysfunction, but the association of NT-proBNP with intradialytic hypotension is not clear.

METHODS

We performed a post hoc analysis of a randomized trial that tested mannitol versus placebo in 52 patients initiating hemodialysis (NCT01520207). NT-proBNP was measured prior to the first and third sessions (n = 87). Mixed-effects models (adjusting for randomized treatment, sex, race, age, diabetes, heart failure, catheter use, pre-dialysis systolic blood pressure, pre-dialysis weight, ultrafiltration volume, serum sodium, bicarbonate, urea nitrogen, phosphate, albumin, hemoglobin, and session length) were fit to examine the association of NT-proBNP with systolic blood pressure decline (pre-dialysis minus nadir systolic blood pressure). Additionally, mixed-effects Poisson models were fit to examine the association with intradialytic hypotension (≥20 mmHg decline in systolic blood pressure).

FINDINGS

Mean age was 55 ± 16 years; 33% had baseline heart failure. The median NT-proBNP was 5498 [25th-75th percentile 2011, 14,790] pg/mL; 26 sessions (30%) were complicated by intradialytic hypotension. In adjusted models, each unit higher log-NT-proBNP was associated with 6.0 mmHg less decline in systolic blood pressure (95%CI -9.2 to -2.8). Higher pre-dialysis NT-proBNP, per log-unit, was associated with a 52% lower risk of intradialytic hypotension (IRR 0.48, 95%CI 0.23-0.97), without evidence for effect modification by randomized treatment (P-interaction = 0.17).

DISCUSSION

In patients initiating hemodialysis, higher NT-proBNP is associated with less decline in intradialytic systolic blood pressure and lower risk of intradialytic hypotension. Future studies should investigate if higher pre-dialysis NT-proBNP levels may identify patients who might tolerate more aggressive ultrafiltration.

Construction of an Early Alert System for Intradialytic Hypotension before Initiating Hemodialysis Based on Machine Learning

Introduction

Intradialytic hypotension (IDH) is prevalent and associated with high hospitalization and mortality rates. The purpose of this study was to explore the risk factors for IDH and use artificial intelligence to establish an early alert system before hemodialysis sessions to identify patients at high risk of IDH.

Materials and Methods

We obtained data on 314,534 hemodialysis sessions conducted at Sichuan Provincial People's Hospital from the renal disease treatment information system. IDH was defined as a systolic blood pressure drop ≥20 mm Hg, a mean arterial pressure drop ≥10 mm Hg during dialysis, or the occurrence of clinical hypotensive events requiring nursing intervention. After pre-processing, the data were randomly divided into training (80%) and testing (20%) sets. Four interpolation methods, three feature selection methods, and 18 machine learning algorithms were used to construct predictive models. The area under the receiver operating characteristic curve (AUC) was the main indicator for evaluating the performance of the models, while Shapley Additive ExPlanation was used to explain the contribution of each variable to the best predictive model.

Results

A total of 3,906 patients and 314,534 dialysis sessions were included, of which 142,237 cases showed IDH (incidence rate, 45.2%). Nineteen parameters were identified through artificial intelligence feature screening. They included age, pre-dialysis weight, dry weight, pre-dialysis blood pressure, heart rate, prescribed ultrafiltration, blood cell counts (neutrophil, lymphocyte, monocyte, eosinophil, lymphocyte, and platelet counts), hematocrit, serum calcium, creatinine, urea, glucose, and uric acid. Random forest, gradient boosting, and logistic regression were the three best models, and the AUCs were 0.812 (95% confidence interval [CI], 0.811-0.813), 0.748 (95% CI, 0.747-0.749), and 0.743 (95% CI, 0.742-0.744), respectively.

Conclusion

Our dialysis software-based artificial intelligence alert system can be used to predict IDH occurrence, enabling the initiation of relevant interventions.

Time of hemodialysis and risk of intradialytic hypotension and intradialytic hypertension in maintenance hemodialysis

Intradialytic hypotension and intradialytic hypertension are complications of hemodialysis (HD) associated with a higher risk of cardiovascular disease (CVD) and death. Blood pressure (BP) normally fluctuates in a circadian pattern, but whether the risk of intradialytic hypotension and intradialytic hypertension varies according to the time of the HD session is unknown. We analyzed two cohorts of thrice-weekly maintenance HD (N = 1838 patients/n = 64,503 sessions from the Hemodialysis [HEMO] Study, and N = 3302 patients/n = 33,590 sessions from Satellite Healthcare). Random effects logistic regression models examined the association of HD start time (at or before 9:00 a.m. [early AM], between 9:01 a.m. and 12:00 p.m. [late AM], and at or after 12:01 p.m. [PM]) with intradialytic hypotension (defined as nadir intra-HD systolic BP (SBP) < 90 mmHg if pre-HD SBP < 160 mmHg, or <100 mmHg if pre-HD SBP ≥ 160 mmHg) and intradialytic hypertension (SBP increase ≥ 10 mmHg from pre-HD to post-HD). Compared to early AM, late AM and PM were associated with an 8% (aOR 0.92, 95% CI 0.83-1.02) and a 16% (aOR 0.84, 95% CI 0.75-0.95) lower risk of intradialytic hypotension in HEMO, respectively. Conversely, compared to early AM, a monotonic higher risk of intradialytic hypertension was observed for late AM (aOR 1.23, 95% CI 1.12-1.35) and PM (aOR 1.41, 95% CI 1.27-1.56) in HEMO. These findings were consistent in Satellite. In two large cohorts of maintenance HD, we observed a monotonic lower risk of intradialytic hypotension and a monotonic higher risk of intradialytic hypertension with later dialysis start times. Whether HD treatment allocation to certain times of the day in hypotensive-prone or hypertensive-prone patients improves outcomes deserves further investigation.

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.

Prediction of intradialytic hypotension using pre-dialysis features-a deep learning-based artificial intelligence model

BACKGROUND

Intradialytic hypotension (IDH) is a serious complication of hemodialysis (HD) that is associated with increased risks of cardiovascular morbidity and mortality. However, its accurate prediction remains a clinical challenge. The aim of this study was to develop a deep learning-based artificial intelligence (AI) model to predict IDH using pre-dialysis features.

METHODS

Data from 2007 patients with 943 220 HD sessions at seven university hospitals were used. The performance of the deep learning model was compared with three machine learning models (logistic regression, random forest and XGBoost).

RESULTS

IDH occurred in 5.39% of all studied HD sessions. A lower pre-dialysis blood pressure (BP), and a higher ultrafiltration (UF) target rate and interdialytic weight gain in IDH sessions compared with non-IDH sessions, and the occurrence of IDH in previous sessions was more frequent among IDH sessions compared with non-IDH sessions. Matthews correlation coefficient and macro-averaged F1 score were used to evaluate both positive and negative prediction performances. Both values were similar in logistic regression, random forest, XGBoost and deep learning models, developed with data from a single session. When combining data from the previous three sessions, the prediction performance of the deep learning model improved and became superior to that of other models. The common top-ranked features for IDH prediction were mean systolic BP (SBP) during the previous session, UF target rate, pre-dialysis SBP, and IDH experience during the previous session.

CONCLUSIONS

Our AI model predicts IDH accurately, suggesting it as a reliable tool for HD treatment.

Seasonal variation in predialysis systolic blood pressure and cardiovascular events in patients on maintenance hemodialysis

Predialysis systolic blood pressure (SBP) in patients on hemodialysis (HD) consistently followed a seasonal pattern, reaching a peak in winter and nadir in summer, similar to blood pressure in the general population. However, the relationship between seasonal variations in predialysis SBP and clinical outcomes is still under-investigated in Japanese patients on HD. This retrospective cohort study included 307 Japanese patients undergoing HD for >1 year in three dialysis clinics and evaluated the association between the standard deviation (SD) of predialysis SBP and clinical outcomes, including major adverse cardiovascular events (MACEs; cardiovascular death, nonfatal myocardial infarction or unstable angina, stroke, heart failure, and other severe cardiovascular events requiring hospitalization) with 2.5 years follow-up. The SD of predialysis SBP was 8.2 (6.4-10.9) mmHg. In the model fully adjusted for the SD of predialysis SBP, predialysis SBP, age, sex, HD vintage, Charlson comorbidity index, ultrafiltration rate, renin-angiotensin system inhibitors, corrected calcium, phosphorus, human atrial natriuretic peptide, C-reactive protein, albumin, hemoglobin, body mass index, normalized protein catabolism rate, and intradialytic SBP decline, Cox regression analyses showed that a higher SD of predialysis SBP (per 10 mmHg) was significantly associated with increased MACE risk (hazard ratio [HR], 1.89; 95% confidence interval [95% CI], 1.07-3.36) and all-cause hospitalization (HR, 1.57; 95% CI, 1.07-2.30). Therefore, greater seasonal variations in predialysis SBP were associated with worse clinical outcomes, including MACEs and all-cause hospitalization. Whether interventions to reduce seasonal variations in predialysis SBP will improve the prognosis of Japanese patients on HD must be investigated further.

Motion Artifacts Reduction for Noninvasive Hemodynamic Monitoring of Conscious Patients Using Electrical Impedance Tomography: A Preliminary Study

Electrical impedance tomography (EIT) can monitor the real-time hemodynamic state of a conscious and spontaneously breathing patient noninvasively. However, cardiac volume signal (CVS) extracted from EIT images has a small amplitude and is sensitive to motion artifacts (MAs). This study aimed to develop a new algorithm to reduce MAs from the CVS for more accurate heart rate (HR) and cardiac output (CO) monitoring in patients undergoing hemodialysis based on the source consistency between the electrocardiogram (ECG) and the CVS of heartbeats. Two signals were measured at different locations on the body through independent instruments and electrodes, but the frequency and phase were matched when no MAs occurred. A total of 36 measurements with 113 one-hour sub-datasets were collected from 14 patients. As the number of motions per hour (MI) increased over 30, the proposed algorithm had a correlation of 0.83 and a precision of 1.65 beats per minute (BPM) compared to the conventional statical algorithm of a correlation of 0.56 and a precision of 4.04 BPM. For CO monitoring, the precision and upper limit of the mean ∆CO were 3.41 and 2.82 L per minute (LPM), respectively, compared to 4.05 and 3.82 LPM for the statistical algorithm. The developed algorithm could reduce MAs and improve HR/CO monitoring accuracy and reliability by at least two times, particularly in high-motion environments.

Bradykinin B2 receptor blockade and intradialytic hypotension

INTRODUCTION

Intradialytic hypotension (IDH) is a common clinical complication and is associated with increased morbidity and mortality in patients undergoing maintenance hemodialysis (MHD). The pathogenesis of IDH has been attributed to the rapid reduction of plasma volume during hemodialysis and the inadequate compensatory mechanisms in response to hypovolemia, such as the lack of vasoconstriction. This may be due to the increased production of vasodilators, such as bradykinin. In this study we test the hypothesis that bradykinin B2 receptor blockade prevents intradialytic hypotension.

METHODS

We performed a post-hoc analysis of a double-blind, placebo-controlled, randomized, 2 × 2 crossover clinical trial comparing the continuous infusion of icatibant, a bradykinin B2 receptor blocker, and placebo during hemodialysis. Icatibant or placebo was infused for 30 min before and during hemodialysis in 11 patients on MHD.

RESULTS

Seven of the patients had IDH, defined as a reduction of systolic blood pressure equal to or greater than 20 mmHg during hemodialysis. Stratified analysis, based on the presence of IDH, revealed that icatibant prevented the decrease in blood pressure compared to placebo in patients with IDH [blood pressure at average nadir (2.5 h after hemodialysis): Placebo,114.3 ± 8.9 vs. icatibant, 125.6 ± 9.1 mmHg, mean ± S.E.M]. Icatibant did not affect blood pressure in the group of patients without IDH.

CONCLUSION

Bradykinin B2 receptor blocker may prevent the occurrence of IDH. Further studies should evaluate the hemodynamic effects of icatibant during hemodialysis and the symptomatology associated with IDH.

A Randomized Trial Examining the Impact of Timing of Intradialytic Cycling on Intradialytic Hypotension

Introduction

Intradialytic cycling is often performed during the first half of hemodialysis because of concerns regarding increased frequency of intradialytic hypotension (IDH) late in hemodialysis. This increases exercise program resource needs and limits utility of intradialytic cycling to treat dialysis-related symptoms.

Methods

This multicenter, randomized, crossover trial compared IDH rate when cycling during the first half versus the second half of hemodialysis in 98 adults on maintenance hemodialysis. Group A cycled during the first half of hemodialysis for 2 weeks and subsequently during the second half for 2 weeks. In group B, the cycling schedule was reversed. Blood pressure (BP) was measured every 15 minutes throughout hemodialysis. Primary outcome was IDH rate (systolic BP [SBP] decrease of >20 mm Hg or SBP <90 mm Hg). Secondary outcomes included symptomatic IDH rate and time to recover post hemodialysis. Data were analyzed using negative binomial and gamma distribution mixed regression.

Results

Mean age 64.7 (SD 12.0) and 64.7 (SD 14.2) years in group A (n = 52) and group B (n = 46), respectively. Proportions of females were 33% in group A and 43% in group B. Median time on hemodialysis was 4.1 (interquartile range [IQR] 2.5, 6.1]) years in group A and 3.9 years (IQR 2.5, 6.7) in group B. IDH rate per 100 hemodialysis hours (95% confidence interval [CI]) was 34.2 (26.4, 42.0) and 36.0 (28.9, 43.1) during early and late intradialytic cycling, respectively (P = 0.53). Timing of intradialytic cycling was not associated with symptomatic IDH (relative risk [RR]: 1.07 [0.75-1.53]) or time to recover post hemodialysis (odds ratio: 0.99 [0.79-1.23]).

Conclusion

We found no association between the rate of overall or symptomatic IDH and the timing of intradialytic cycling in patients enrolled in an intradialytic cycling program. Increased use of cycling late in hemodialysis may optimize intradialytic cycling program resource use and should be studied as a possible treatment for symptoms common in late hemodialysis.

A comparative study of the definitions of intradialytic hypotension correlated with increased mortality to identify universal predictors

Intradialytic hypotension (IDH) is a common complication in patients undergoing hemodialysis therapy. No consensus on the definition of intradialytic hypotension has been established so far. As a result, coherent and consistent evaluation of its effects and causes is difficult. Some studies have highlighted existing correlations between certain definitions of IDH and the risk of mortality for the patients. This work is mainly focused on these definitions. Our aim is to understand if different IDH definitions, all correlated with increased mortality risk, catch the same onset mechanisms or dynamics. To check whether the dynamics captured by these definitions are similar, we performed analyses of the incidence, of the IDH event onset timing, and checked whether there were similarities between the definitions in those aspects. We evaluated how these definitions overlap with each other and we evaluated which common factors could allow identifying patients at risk of IDH at the beginning of a dialysis session. The definitions of IDH we analyzed through statistical and machine learning approaches, showed a variable incidence on the HD sessions and had different onset time. We found that the set of parameters relevant for the prediction of the IDH was not always the same for the definitions considered. However, it can be observed that some predictors, such as the presence of comorbidities such as diabetes or heart disease, and a low pre-dialysis diastolic blood pressure, have shown universal relevance in highlighting an increased risk of IDH during the treatment. Among those parameters, the one that showed a major importance is the diabetes status of the patients. Diabetes or heart disease presence are permanent risk factors pointing out an increased IDH risk during the treatments, while, pre-dialysis diastolic blood pressure is instead a parameter that can change at every session and should be used to evaluate the specific risk to develop IDH for each session. The identified parameters could be used in the future to train more complex prediction models.

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.

Mean annual intradialytic blood pressure decline and cardiovascular events in Japanese patients on maintenance hemodialysis

An intradialytic systolic blood pressure (SBP) decline, which defines intradialytic hypotension, may be associated with higher all-cause mortality. However, in Japanese patients on hemodialysis (HD), the association between intradialytic SBP decline and patient outcomes is unclear. This retrospective cohort study included 307 Japanese patients undergoing HD over 1 year in three dialysis clinics and evaluated the association between the mean annual intradialytic SBP decline (predialysis SBP-nadir intradialytic SBP) and clinical outcomes, including major adverse cardiovascular events (MACEs; cardiovascular death, nonfatal myocardial infarction or unstable angina, stroke, heart failure, and other severe cardiovascular events requiring hospitalization) by following up for 2 years. The mean annual intradialytic SBP decline was 24.2 (25-75th percentile, 18.3-35.0) mmHg. In the model fully adjusted for intradialytic SBP decline tertile group (T1, <20.4 mmHg; T2, 20.4 to <29.9 mmHg; T3, ≥29.9 mmHg), predialysis SBP, age, sex, HD vintage, Charlson comorbidity index, ultrafiltration rate, use of renin-angiotensin system inhibitors, corrected calcium, phosphorus, human atrial natriuretic peptide, geriatric nutritional risk index, normalized protein catabolism rate, C-reactive protein, hemoglobin, and use of pressor agents, Cox regression analyses showed that the hazard ratio (HR) was significantly higher for T3 than for T1 for MACEs (HR, 2.38; 95% confidence interval 1.12-5.09) and all-cause hospitalization (HR, 1.68; 95% confidence interval 1.03-2.74). Therefore, in Japanese patients on HD, a greater intradialytic SBP decline was associated with worse clinical outcomes. Further studies are warranted to investigate whether interventions to attenuate the intradialytic SBP decline will improve the prognosis of Japanese patients on HD.

Longitudinal changes in uric acid concentration and their relationship with chronic kidney disease progression in children and adolescents

BACKGROUND

Elevated serum uric acid concentration is a risk factor for CKD progression. Its change over time and association with CKD etiology and concomitant changes in estimated glomerular filtration rate (eGFR) in children and adolescents are unknown.

METHODS

Longitudinal study of 153 children/adolescents with glomerular (G) and 540 with non-glomerular (NG) etiology from the CKD in Children (CKiD) study. Baseline serum uric acid, change in uric acid and eGFR over time, CKD etiology, and comorbidities were monitored. Adjusted linear mixed-effects regression models quantified the relationship between within-person changes in uric acid and concurrent within-person changes in eGFR.

RESULTS

Participants with stable uric acid over follow-up had CKD progression which became worse for increased baseline uric acid (average annual percentage changes in eGFR were - 1.4%, - 7.7%, and - 14.7% in those with G CKD with baseline uric acid < 5.5 mg/dL, 5.5 - 7.5 mg/dL, and > 7.5 mg/dL, respectively; these changes were - 1.4%, - 4.1%, and - 8.6% in NG CKD). Each 1 mg/dL increase in uric acid over follow-up was independently associated with significant concomitant eGFR decreases of - 5.7% (95%CI - 8.4 to - 3.0%) (G) and - 5.1% (95%CI - 6.3 to - 4.0%) (NG) for those with baseline uric acid < 5.5 mg/dL and - 4.3% (95%CI - 6.8 to - 1.6%) (G) and - 3.3% (95%CI - 4.1 to - 2.6%) (NG) with baseline uric acid between 5.5 and 7.5 mg/dL.

CONCLUSIONS

Higher uric acid levels and increases in uric acid over time are risk factors for more severe progression of CKD in children and adolescents. A higher resolution version of the Graphical abstract is available as Supplementary information.

Changes of Hemodynamic Parameters after Intradialytic Glucose Injection

BACKGROUND

Intradialytic hypotension (IDH) is a frequent complication of hemodialysis (HD). Current methods of IDH prevention are insufficient.

METHODS

We analyzed the intradialytic time course of systolic (SBP), diastolic (DBP), mean arterial (MAP), pulse pressure (PP), and heart rate (HR) in a group of chronic kidney disease (CKD) patients. First, 30 min into HD, a 40% glucose solution was injected into the venous line of the extracorporeal circulation at a dose of 0.5 g/kg of dry weight. Pressures and HR were measured in frequent intervals. Relative volume overload was determined by bioimpedance spectroscopy.

RESULTS

Thirty-five participants were studied. SBP increased after 5, 10, and 20 min of glucose infusion. DBP increased after 2 and 3 h and also at the end of HD. PP increased after 5, 10, and 20 min of glucose infusion and fell after the 2nd and 3rd hour and also at the end of HD. MAP increased after 2 and 3 h of glucose injection and at the end of HD. Significant interactions of the time course of SBP, DBP, MAP, with HR at baseline and of the time course of PP with fluid overload were observed. Symptomatic hypotensive episodes were absent.

CONCLUSIONS

Glucose infusions during HD prevent symptomatic IDH and do not cause severe hypertensive episodes.

Circumferential Strain as a Marker of Vessel Reactivity in Patients with Intradialytic Hypotension

Background and Objectives: Intradialytic hypotension (IDH) complicates 4 to 39.9% of hemodialysis (HD) sessions. Vessels' reactivity disturbances may be responsible for this complication. Two-dimensional speckle tracking is used to assess arterial circumferential strain (CS) as a marker of the effectiveness of the cardiovascular response to the reduction of circulating plasma. Materials and Methods: The common carotid artery (CCA) and common iliac artery (CIA) CSs were recorded using ultrasonography in 68 chronically dialyzed patients before and after one HD session. Results: In patients with IDH episodes (n = 26), the CCA-CS was significantly lower both before (6.28 ± 2.34 vs. 4.63 ± 1.74 p = 0.003) and after HD (5.00 (3.53-6.78) vs. 3.79 ± 1.47 p = 0.010) than it was in patients without this complication. No relationship was observed between CIA-CS and IDH. IDH patients had a significantly higher UF rate; however, they did not differ compared to complication-free patients either in anthropometric or laboratory parameters. Conclusions: Patients with IDH were characterized by lower pre- and post-HD circumferential strain of the common carotid artery. The lower CCA-CS showed that impaired vascular reactivity is one of the most important risk factors for this complication's occurrence.

Echocardiogram screening in pediatric dialysis and transplantation

Transthoracic echocardiography is commonly used to identify structural and functional cardiac abnormalities that can be prevalent in childhood chronic kidney failure (KF). Left ventricular mass (LVM) increase is most frequently reported and may persist post-kidney transplant especially with hypertension and obesity. While systolic dysfunction is infrequently seen in childhood chronic KF, systolic strain identified by speckle tracking echocardiography has been frequently identified in dialysis and it can also persist post-transplant. Echocardiogram association with long-term outcomes has not been studied in childhood KF but there are many adult studies demonstrating associations between increased LVM, systolic dysfunction, strain, diastolic dysfunction, and cardiovascular events and mortality. There has been limited study of interventions to improve echocardiogram status. In childhood, improved blood pressure has been associated with better LVM, and conversion from hemodialysis to hemodiafiltration has been associated with better diastolic and systolic function. Whether long-term cardiac outcomes are also improved with these interventions is unclear. Echocardiography is a well-established technique, and regular use in childhood chronic KF seems justified. A case can be made to extend screening to include speckle tracking echocardiography and intradialytic studies in high-risk populations. Further longitudinal studies including these newer echocardiogram modalities, interventions, and long-term outcomes would help clarify recommendations for optimal use as a screening tool.

A novel double parameters based biofeedback system to prevent intradialytic hypotension in clinical practice: Case report

Intradialytic hypotension (IDH) still represents the main complication during dialysis treatment. Patient's discomfort, reduced dialysis efficiency, reduced treatment time are only some of the main problems that could derive from the need to stop or temporarily interrupt the treatment because of IDH. Up to now, different types of treatment (HDF, HF, or AFB) have been considered to prevent IDH as well as the use of biofeedback systems (Blood Volume Monitoring, Temperature control, Sodium profiling, Blood Pressure monitoring). Recently a new biofeedback system (Biologic Fusion^®) controlling simultaneously blood pressure (BP) and relative blood volume changes (RBV) has been developed to prevent IDH. This system runs according to fuzzy logic. We describe how this system works and to a better understanding, we report a clinical case of a patient with frequent IDH treated with the use of this system.

Construction of haemodialysis nursing-sensitive quality indicators based on Donabedian theory: A Delphi method study

AIMS

To establish a sensitive, scientific and practical evaluation system for haemodialysis nursing and to provide a reference for the evaluation of haemodialysis nursing quality.

DESIGN

Through a literature review and Delphi method.

METHOD

According to the literature review, a preliminary nursing-sensitive quality indicators for haemodialysis were established, and an expert survey questionnaire was designed. Finally, the evaluation system for the nursing-sensitive quality indicators was determined using the Delphi method.

RESULTS

Thirteen nursing-sensitive quality indicators for haemodialysis were finally constructed, including two structural indicators, three process indicators and eight outcome indicators. The effective recovery rate of the two rounds of expert survey questionnaires was 100%, the coefficient of judgement basis is 0.956, the coefficient of familiarity is 0.833, the coefficient of authority is 0.895, and the Kendall's harmony coefficients of the two rounds of expert consultation were 0.158 ~ 0.307 and 0.170 ~ 0.315, respectively, with statistical significance (p < .05).

CLINICAL RELEVANCE

In this study, the nursing-sensitive quality indicators for haemodialysis were developed by the Delphi method and included structural indicators, outcome indicators and process indicators, which made up for some deficiencies noted in previous studies. The authors have provided a more reliable and comprehensive basis for evaluating the quality and safety of haemodialysis nursing in the future.

Deep Learning Model for Predicting Intradialytic Hypotension Without Privacy Infringement: A Retrospective Two-Center Study

Objective

Previously developed Intradialytic hypotension (IDH) prediction models utilize clinical variables with potential privacy protection issues. We developed an IDH prediction model using minimal variables, without the risk of privacy infringement.

Methods

Unidentifiable data from 63,640 hemodialysis sessions (26,746 of 79 patients for internal validation, 36,894 of 255 patients for external validation) from two Korean hospital hemodialysis databases were finally analyzed, using three IDH definitions: (1) systolic blood pressure (SBP) nadir <90 mmHg (Nadir90); (2) SBP decrease ≥20 mmHg from baseline (Fall20); and (3) SBP decrease ≥20 mmHg and/or mean arterial pressure decrease ≥10 mmHg (Fall20/MAP10). The developed models use 30 min information to predict an IDH event in the following 10 min window. Area under the receiver operating characteristic curves (AUROCs) and precision-recall curves were used to compare machine learning and deep learning models by logistic regression, XGBoost, and convolutional neural networks.

Results

Among 344,714 segments, 9,154 (2.7%), 134,988 (39.2%), and 149,674 (43.4%) IDH events occurred according to three different IDH definitions (Nadir90, Fall20, and Fall20/MAP10, respectively). Compared with models including logistic regression, random forest, and XGBoost, the deep learning model achieved the best performance in predicting IDH (AUROCs: Nadir90, 0.905; Fall20, 0.864; Fall20/MAP10, 0.863) only using measurements from hemodialysis machine during dialysis session.

Conclusions

The deep learning model performed well only using monitoring measurement of hemodialysis machine in predicting IDH without any personal information that could risk privacy infringement.

Risk of Intradialytic Hypotension by Day of the Week in Maintenance Hemodialysis

Intradialytic hypotension (IDH) is a common complication of hemodialysis (HD) and is associated with a higher risk of cardiovascular (CV) events and mortality. CV events are more common on the days of HD, especially following the longer interdialytic interval. We investigated the risk of IDH according to day of HD in adults undergoing in-center, thrice-weekly HD in the Hemodialysis (HEMO) Study (N = 1,837 patients; n = 64,474 sessions), and the DaVita Clinical Research biorepository [BioReG]) (N = 952 patients; n = 61,197 sessions). Random effects logistic regression models assessed the risk of IDH (defined as nadir intra-HD systolic blood pressure [SBP] <90 mm Hg if pre-HD SBP <160 mm Hg, or <100 mm Hg if pre-HD SBP ≥160 mm Hg [Nadir90/100 definition]) according to HD day (Mon/Tue [HD1]; Wed/Thu [HD2]; Fri/Sat [HD3]). Alternative definitions of IDH were explored. Nadir90/100 occurred in 14% of HEMO and 18% of BioReG sessions. A monotonic increase in the risk of IDH was observed for HD2 and HD3, compared with HD1, for all IDH definitions in both cohorts. Compared with HD1, HD2 was associated with a 10% higher risk of Nadir90/100 (adjusted odds ratio, 1.10; 95% CI, 1.03-1.17) and HD3 was associated with a 31% higher risk (adjusted odds ratio, 1.31; 95% CI, 1.19-1.45) in HEMO, with consistent results in BioReG. We observed a monotonic increased risk of IDH with later days of the dialytic week in two separate cohorts. Further research to determine the underlying mechanisms is necessary to guide strategies for IDH prevention.

Clinical Prediction of Heart Failure in Hemodialysis Patients: Based on the Extreme Gradient Boosting Method

Background: Heart failure (HF) is the main cause of mortality in hemodialysis (HD) patients. However, it is still a challenge for the prediction of HF in HD patients. Therefore, we aimed to establish and validate a prediction model to predict HF events in HD patients.

Methods: A total of 355 maintenance HD patients from two hospitals were included in this retrospective study. A total of 21 variables, including traditional demographic characteristics, medical history, and blood biochemical indicators, were used. Two classification models were established based on the extreme gradient boosting (XGBoost) algorithm and traditional linear logistic regression. The performance of the two models was evaluated based on calibration curves and area under the receiver operating characteristic curves (AUCs). Feature importance and SHapley Additive exPlanation (SHAP) were used to recognize risk factors from the variables. The Kaplan–Meier curve of each risk factor was constructed and compared with the log-rank test.

Results: Compared with the traditional linear logistic regression, the XGBoost model had better performance in accuracy (78.5 vs. 74.8%), sensitivity (79.6 vs. 75.6%), specificity (78.1 vs. 74.4%), and AUC (0.814 vs. 0.722). The feature importance and SHAP value of XGBoost indicated that age, hypertension, platelet count (PLT), C-reactive protein (CRP), and white blood cell count (WBC) were risk factors of HF. These results were further confirmed by Kaplan–Meier curves.

Conclusions: The HF prediction model based on XGBoost had a satisfactory performance in predicting HF events, which could prove to be a useful tool for the early prediction of HF in HD.

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.

10-Year clinical outcomes of hemodialysis patients with peripheral arterial disease due to infrainguinal disease undergoing endovascular therapy

Although symptomatic peripheral arterial disease (PAD) is common in patients with hemodialysis (HD), few studies have evaluated the long-term clinical outcomes of revascularization in this population. The aim of the current study was to investigate the 10-year clinical outcomes of HD patients with PAD undergoing endovascular therapy (EVT). We retrospectively analyzed 750 limbs from 578 HD patients with symptomatic PAD due to infrainguinal lesions, treated with EVT, between May 2004 and November 2011. The primary outcome was 10-year mortality and the secondary outcome was 10-year freedom from major adverse limb events (MALEs). Predictors for each outcome were evaluated by Cox proportional-hazards model. The 10-year rate of survival and freedom from MALEs was 23.6 ± 3.1% and 76.4 ± 2.9%, respectively. In the multivariate analysis, patients with over 80 years [hazard ratio (HR) 2.10; 95% confidence interval (CI) 1.58-2.80; p < 0.001], non-ambulatory status (HR 1.55; 95% CI 1.19-2.03; p = 0.001), absence of hypertension (HR 1.59; 95% CI 1.19-2.08; p = 0.001), heart failure (HR 1.36; 95% CI 1.02-1.80; p = 0.03), and tissue loss (HR 1.65; 95% CI 1.28-2.12; p < 0.001) were at an increased risk of 10-year mortality. Cerebrovascular diseases (HR 1.60; 95% CI 1.03-2.49; p = 0.038), no cilostazol use (HR 1.69; 95% CI 1.09-2.70; p = 0.021), tissue loss (HR 3.87; 95% CI 2.37-6.34; p < 0.001), and poor below-the-knee (BTK) run-off (HR 1.68; 95% CI 1.04-2.71; p = 0.035) were significantly associated with MALEs. After risk stratification analysis based on risk score assignment according to number of predictors, 10-year survival and freedom from MALE were lower in the higher score groups (10-year survival rates according to number of risk factors: 0, 35.1%; 1, 20.3%; 2-5, 10.8%; respectively, p < 0.001, 10-year freedom from MALE rates in patients with greater number of risk factors: 0-1, 90.2%; 2-3, 65.5%; 4-5, 61.6%; respectively, p < 0.001). The 10-year clinical outcomes after EVT for HD patients with PAD due to infrainguinal disease were clinically suboptimal. Risk stratification based on these predictors before EVT would be useful in estimating future adverse outcome.

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.

Comparison of intradialytic blood pressure metrics as predictors of all-cause mortality

Background

Intradialytic hypotension (IDH) has been reported to be an important prognostic factor in hemodialysis patients. However, a standard definition of IDH has not yet been determined.

Methods

We retrospectively analyzed blood pressure (BP) metrics obtained during serial dialysis sessions over a 90-day period from a single dialysis center from 2016 to 2017. The mean values and the frequency of specific values of BP were analyzed as predictors of 3-year mortality.

Results

A total of 430 patients who underwent maintenance dialysis were included. The mean age was 63.3 ± 12.4 years and 58.6% were male. A low minimum systolic blood pressure (SBP) <110 mmHg during dialysis was significantly associated with increased all-cause mortality. The frequency of a minimum SBP <100 mmHg was the most significant predictor of 3-year mortality, with an area under the curve (AUC) of 0.722. Furthermore, the frequency of a minimum SBP <100 mmHg significantly increased the predictability of mortality when combined with the presence of other clinical factors including age, body mass index and vascular access type (AUC 0.786 vs. 0.835; p = 0.005).

Conclusion

Among the various intradialytic BP metrics, the frequency of a minimum SBP <100 mmHg is the most significant factor related to all-cause mortality. The guidelines for the management of blood pressure in dialysis patients should consider including a minimum SBP <100 mmHg as a definition for IDH.

High ultrafiltration rate induced intradialytic hypotension is a predictor for cardiac remodeling: a 5-year cohort study

BACKGROUND

Intradialytic-hypotension (IDH) is a common complication of hemodialysis. High ultrafiltration rate (UFR) might lead to IDH. However, the relationships between UFR, IDH, and cardiac remodeling among hemodialysis patients in the long-term have not been deeply explored.

METHODS

This retrospective cohort study collected clinical and echocardiographic data. Patients were enrolled from 1 January 2014 to 31 March 2014 and were followed-up for 5-year. Those who suffered from more than four hypotensive events during three months (10% of dialysis treatments) were defined as the IDH group. Subgroup analysis was done according to the UFR of 10 ml/h/kg. Associations between UFR, IDH, and alterations of cardiac structure/function were analyzed.

RESULTS

Among 209 patients, 96 were identified with IDH (45.9%). The survival rate of IDH patients was lower than that of no-IDH patients (65.5% vs. 81.4%, p = .005). In IDH group, decreased ejection fraction (EF), larger left atrium diameter index (LADI), and left ventricular mass index (LVMI) (p < .05) were observed at the end of the follow-up. In multivariate logistic model, the interaction between UFR and IDH was notably associated with LVMI variation (OR = 1.37). After adjusting covariates, UFR was still an independent risk factor of LVMI variation (OR = 1.52) in IDH group. In subsequent analysis, we divided patients according to UFR 10 ml/h/kg. For IDH-prone patients, decreased EF, larger LADI, and LVMI (p < .05) were observed at the end of the study only in high-UFR group.

CONCLUSIONS

UFR and IDH have interactions on cardiac remodeling. High ultrafiltration rate induced IDH is a predictor for cardiac remodeling in long-term follow-up.

Multitargeted interventions to reduce dialysis-induced systemic stress

Hemodialysis (HD) is a life-sustaining therapy as well as an intermittent and repetitive stress condition for the patient. In ridding the blood of unwanted substances and excess fluid from the blood, the extracorporeal procedure simultaneously induces persistent physiological changes that adversely affect several organs. Dialysis patients experience this systemic stress condition usually thrice weekly and sometimes more frequently depending on the treatment schedule. Dialysis-induced systemic stress results from multifactorial components that include treatment schedule (i.e. modality, treatment time), hemodynamic management (i.e. ultrafiltration, weight loss), intensity of solute fluxes, osmotic and electrolytic shifts and interaction of blood with components of the extracorporeal circuit. Intradialytic morbidity (i.e. hypovolemia, intradialytic hypotension, hypoxia) is the clinical expression of this systemic stress that may act as a disease modifier, resulting in multiorgan injury and long-term morbidity. Thus, while lifesaving, HD exposes the patient to several systemic stressors, both hemodynamic and non-hemodynamic in origin. In addition, a combination of cardiocirculatory stress, greatly conditioned by the switch from hypervolemia to hypovolemia, hypoxemia and electrolyte changes may create pro-arrhythmogenic conditions. Moreover, contact of blood with components of the extracorporeal circuit directly activate circulating cells (i.e. macrophages-monocytes or platelets) and protein systems (i.e. coagulation, complement, contact phase kallikrein-kinin system), leading to induction of pro-inflammatory cytokines and resulting in chronic low-grade inflammation, further contributing to poor outcomes. The multifactorial, repetitive HD-induced stress that globally reduces tissue perfusion and oxygenation could have deleterious long-term consequences on the functionality of vital organs such as heart, brain, liver and kidney. In this article, we summarize the multisystemic pathophysiological consequences of the main circulatory stress factors. Strategies to mitigate their effects to provide more cardioprotective and personalized dialytic therapies are proposed to reduce the systemic burden of HD.

Changes in total and segmental extracellular and intracellular volumes with hypotension during hemodialysis measured with bioimpedance spectroscopy

BACKGROUND

Bioelectrical impedance analysis (BIA) devices have been advocated to guide volume management in hemodialysis (HD) patients. We hypothesized that understanding the dynamics of fluid shifts in different body segments may provide additional insight on preventive measures to reduce the risk of intradialytic hypotension.

METHODS

A prospective observational study was conducted among 42 HD patients at risk of hypotension who were admitted as emergencies inpatient.

RESULTS

A total of 191 BIA measurements were made during the 42 HD sessions, and hypotension occurred during 52 measurements (27%). The extracellular water (ECW) to intracellular water ratio (EIR) was measured in different body segments and declined significantly only in the non-access arm with increasing HD session duration (β = -0.04; 95% confidence interval (CI): -0.05 to -0.03, p < 0.01). There was no significant association between EIR and hypotension with respect to the different body segments. Only pre-HD N-terminal-pro b-type natriuretic peptide was significantly associated with hypotension (β = 0.20, 95% CI: 0.04 to 0.89, p = 0.04). There was no association between relative blood volume monitoring change and EIR.

CONCLUSION

In summary, we found that segmental BIA during HD was unable to detect or predict hypotension during dialysis. Although BIA is able to provide information about ECW and guide clinical assessment of volume in HD patients prior to dialysis, our findings did not suggest the use of serial measurements of changes in EIR in different body segments during HD provided sufficient information to predict intradialytic hypotension. Similarly, changes in EIR did not provide information on changes in plasma volume that could potentially trigger interventions to prevent or reduce intra-dialytic hypotension.

Toward an individualized determination of dialysis adequacy: a narrative review with special emphasis on incremental hemodialysis

INTRODUCTION

The search for the 'perfect' renal replacement therapy has been paralleled by the search for the perfect biomarkers for assessing dialysis adequacy. Three main families of markers have been assessed: small molecules (prototype: urea); middle molecules (prototype β2-microglobulin); comprehensive and nutritional markers (prototype of the simplified assessment, albumin levels; composite indexes as malnutrition-inflammation score). After an era of standardization of dialysis treatment, personalized dialysis schedules are increasingly proposed, challenging the dogma of thrice-weekly hemodialysis.

AREAS COVERED

In this review, we describe the advantages and limitations of the approaches mentioned above, focusing on the open questions regarding personalized schedules and incremental hemodialysis.

EXPERT OPINION

In the era of personalized dialysis, the assessment of dialysis adequacy should be likewise personalized, due to the limits of 'one size fits all' approaches. We have tried to summarize some of the relevant issues regarding the determination of dialysis adequacy, attempting to adapt them to an elderly, highly comorbidity population, which would probably benefit from tailor-made dialysis prescriptions. While no single biomarker allows precisely tailoring the dialysis dose, we suggest using a combination of clinical and biological markers to prescribe dialysis according to comorbidity, life expectancy, residual kidney function, and small and medium-size molecule depuration.

Benefit of an Internet-Based Management System among Hemodialysis Patients at the Risk of Intradialytic Hypotension and Muscle Cramps: A Controlled before and after Study

BACKGROUND

The purpose of this study was to observe the impact of an internet-based management system on the incidence of intradialytic hypotension (IDH) and muscle cramps in hemodialysis patients.

METHODS

The patients, who underwent maintenance hemodialysis in the center from January 2018 to June 2020, were recruited and divided into the pre-intervention group (before operation of the internet-based hemodialysis management system, from January 2018 to December 2018) and intervention group (after operation of the system, from June 2019 to June 2020). The clinical outcomes were compared between groups.

RESULTS

The compound endpoint of >1 IDH or muscle cramps happened in 182 patients (61.7%) in the pre-intervention group and 99 participants (30.8%) in the intervention group (relative risk [RR] = 0.50 [95% confidence interval [CI], 0.42; 0.60]). IDH occurred in 122 patients (1-5 episodes in 47 patients, 6-10 episodes in 25 patients, and >10 episodes in 50 patients) and 33 patients (30 patients had 1-5 episodes and 3 patients had 6-10 episodes) before and after execution of the internet-based management system, respectively (RR = 0.25 [95% CI, 0.18; 0.35]). The incidence of muscle cramps was significantly decreased (RR = 0.57 [95% CI, 0.45; 0.73]) after the implementation of the system, and the number of patients with 6-10 episodes dropped from 10 to 1. Multivariate analyses also showed significantly lower RRs in the intervention group: 0.29 ([95% CI, 0.20; 0.41]) for IDH and 0.58 ([95% CI, 0.45; 0.74]) for muscle cramps. Compared with the pre-intervention, participants in the intervention group had a large improvement in self-management (p < 0.001) and self-efficacy (p < 0.001).

CONCLUSION

The study found that the internet-based hemodialysis management system was effective in reducing the IDH and muscle cramp events and improving self-management. It provided a significant implication for the development and application of internet-based programs in hemodialysis management.

Integrating Monitoring of Volume Status and Blood Volume-Controlled Ultrafiltration into Extracorporeal Kidney Replacement Therapy

Purpose

Volume management in hemodialysis (HD) requires the ability to assess volume status objectively and determine treatment strategies that achieve euvolemia without compromising hemodynamic stability. The aim of this study was to compare dialysis with and without blood volume-controlled ultrafiltration (UF) in combination with body composition monitoring, and to evaluate indicators for adequate dialysis (Kt/V), ultrafiltration volume, fluid status, and the occurrence of intradialytic morbid events (IME).

Patients and Methods

Patients undergoing hemodialysis or on-line hemodiafiltration with support of a blood volume monitor (BVM) - a feedback control device integrated into the 5008 and 6008 HD systems - were enrolled. Patients received treatment for four weeks using the 6008 CAREsystem and the BVM (6008+). Data on dialysis dose (Kt/V), UF volume and predialysis fluid status were documented. This data was also documented retrospectively for four weeks with (5008+) and without (5008-) the use of the BVM with the 5008 system. Comparisons were analyzed using linear mixed models.

Results

Twenty-four patients were enrolled. Kt/V was unaffected by blood volume-controlled UF (5008- vs 5008+: p=0.230) and was equally achieved with both HD systems (5008+ vs 6008+: p=0.922). The UF volume and fluid status achieved were comparable, independent of the use of UF control with BVM (5008- vs 5008+; UF volume: p=0.166; fluid overload: p=0.390) or the HD system (5008+ vs 6008+: UF volume: p=0.003; fluid overload: p=0.838), except for UF volume being higher in the 6008+ phase. IMEs occurred in less than 3% of treatments, with no difference between study phases.

Conclusion

This study demonstrates that a clinical approach to kidney replacement therapy that tracks volume status and manages intradialytic fluid removal by blood volume-controlled UF delivers adequate dialysis without compromising fluid removal. It maintains volume status and ensures low incidence of IMEs.

Pro-inflammatory cytokines as potential predictors for intradialytic hypotension

Background

Intradialytic hypotension (IDH) is a common complication in maintaining hemodialysis (MHD) patients. Immune activation might be part of the mechanisms. However, the association between pro-inflammatory cytokines and blood pressure (BP) has not been deeply explored. So we aim to evaluate the potential role of pro-inflammatory cytokines in IDH.

Methods

MHD patients starting hemodialysis before January 2016 were enrolled in our retrospective study. Patients' characteristics, laboratory results, and intradialytic BP were collected. IDH was defined as nadir systolic BP ≤ 90 mmHg during hemodialysis. The definition of IDH group was that those who suffered from more than one hypotensive event during one month after the enrollment (10% of dialysis treatments). Spearman correlation analysis and logistic regression were employed to explore the relationship between pro-inflammatory cytokines and IDH.

Results

Among 390 patients, 72 were identified with IDH (18.5%). High levels of serum tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were observed in the IDH group (p < 0.001). Both TNF-α and IL-1β positively correlated with predialysis BP (p < 0.01). Receiver operating characteristic curve (ROC) analysis was used to evaluate the diagnostic accuracy of serum IL-1β and TNF-α for IDH. The area under the curve of IL-1β was 0.772 (95% CI: 0.708-0.836, p < 0.01), and that of TNF-α was 0.701 (95% CI: 0.620-0.781, p < 0.01). After adjusting for patients' characteristics, biochemical parameters, comorbid conditions, predialysis BP, and medications, elevated TNF-α and IL-1β were still risk factors for IDH.

Conclusion

Pro-inflammatory cytokines (TNF-α and IL-1β) could be potential predictors for IDH.

Machine Learning Analysis of Time-Dependent Features for Predicting Adverse Events During Hemodialysis Therapy: Model Development and Validation Study

BACKGROUND

Hemodialysis (HD) therapy is an indispensable tool used in critical care management. Patients undergoing HD are at risk for intradialytic adverse events, ranging from muscle cramps to cardiac arrest. So far, there is no effective HD device-integrated algorithm to assist medical staff in response to these adverse events a step earlier during HD.

OBJECTIVE

We aimed to develop machine learning algorithms to predict intradialytic adverse events in an unbiased manner.

METHODS

Three-month dialysis and physiological time-series data were collected from all patients who underwent maintenance HD therapy at a tertiary care referral center. Dialysis data were collected automatically by HD devices, and physiological data were recorded by medical staff. Intradialytic adverse events were documented by medical staff according to patient complaints. Features extracted from the time series data sets by linear and differential analyses were used for machine learning to predict adverse events during HD.

RESULTS

Time series dialysis data were collected during the 4-hour HD session in 108 patients who underwent maintenance HD therapy. There were a total of 4221 HD sessions, 406 of which involved at least one intradialytic adverse event. Models were built by classification algorithms and evaluated by four-fold cross-validation. The developed algorithm predicted overall intradialytic adverse events, with an area under the curve (AUC) of 0.83, sensitivity of 0.53, and specificity of 0.96. The algorithm also predicted muscle cramps, with an AUC of 0.85, and blood pressure elevation, with an AUC of 0.93. In addition, the model built based on ultrafiltration-unrelated features predicted all types of adverse events, with an AUC of 0.81, indicating that ultrafiltration-unrelated factors also contribute to the onset of adverse events.

CONCLUSIONS

Our results demonstrated that algorithms combining linear and differential analyses with two-class classification machine learning can predict intradialytic adverse events in quasi-real time with high AUCs. Such a methodology implemented with local cloud computation and real-time optimization by personalized HD data could warn clinicians to take timely actions in advance.

The gut microbiota mediates the protective effects of anserine supplementation on hyperuricaemia and associated renal inflammation

Hyperuricaemia is a disease associated with elevated serum uric acid content, which has emerged rapidly in recent decades. The drugs used to treat clinical hyperuricaemia have side effects, and their safety is poor. However, anserine is a natural carnosine derivative that shows an anti-hyperuricaemic effect. A previous study demonstrated that anserine inhibits uric acid synthesis and promotes uric acid excretion, but there is no evidence regarding the effect of anserine from the perspective of the gut microbiota. In this study, the anti-hyperuricaemic and anti-inflammatory effects of anserine were explored in a diet-induced hyperuricaemic mouse model. Anserine alleviated hyperuricaemia and renal inflammation phenotypes, inhibited uric acid biosynthesis, promoted uric acid excretion, and inhibited NLRP3 inflammasome and TLR4/MyD88/NF-κB signalling pathway activation. The results showed that the anti-hyperuricaemic effect of anserine was dependent on the gut microbiota in the germ-free mice experiment. Furthermore, anserine treatment reversed gut microbiota dysbiosis, repaired the intestinal epithelial barrier and increased short-chain fatty acid production. Moreover, the anti-hyperuricaemic effect of anserine was transmissible by transplanting the faecal microbiota from anserine-treated mice, indicating that the protective effects were at least partially mediated by the gut microbiota. Thus, we identified a new and safe prebiotic material to alleviate hyperuricaemia and provided ideas for the development of oligopeptides.

An Analysis of Frequency of Continuous Blood Pressure Variation and Haemodynamic Responses during Haemodialysis

BACKGROUND

Higher beat-to-beat blood pressure (BP) variation during haemodialysis (HD) has been shown to be associated with elevated cardiac damage markers and white matter ischaemic changes in the brain suggesting relevance to end-organ perfusion. We aimed to characterize individual patterns of BP variation and associated haemodynamic responses to HD.

METHODS

Fifty participants underwent continuous non-invasive haemodynamic monitoring during HD and BP variation were assessed using extrema point (EP) frequency analysis. Participants were divided into those with a greater proportion of low frequency (LF, n = 21) and high frequency (HF, n = 22) of BP variation. Clinical and haemodynamic data were compared between groups.

RESULTS

Median EP frequencies for mean arterial pressure (MAP) of mid-week HD sessions were 0.54 Hz (interquartile range 0.18) and correlated with dialysis vintage (r = 0.32, p = 0.039), NT pro-BNP levels (r = 0.32, p = 0.038), and average real variability (ARV) of systolic BP (r = 0.33, p = 0.029), ARV of diastolic BP (r = 0.46, p = 0.002), and ARV of MAP (r = 0.57, p < 0.001). In the LF group, MAP positively correlated with cardiac power index (CPI) in each hour of dialysis, but not with total peripheral resistance index (TPRI). In contrast, in the HF group, MAP correlated with TPRI in each hour of dialysis but only with CPI in the first hour.

CONCLUSIONS

EP frequency analysis of continuous BP monitoring during dialysis allows assessment of BP variation and categorization of individuals into low- or high-frequency groups, which were characterized by different haemodynamic responses to dialysis. This may assist in improved individualization of dialysis therapy.

Sodium and ultrafiltration profiling in hemodialysis: A long-forgotten issue revisited

Sodium and ultrafiltration profiling are method of dialysis in which dialysate sodium concentration and ultrafiltration rate are altered during the course of the dialysis session. Sodium and ultrafiltration profiling have been used, commonly simultaneously, to improve hemodynamic stability during hemodialysis. Sodium profiling is particularly effective in decreasing the incidence of intradialytic hypotension, while ultrafiltration profiling is suggested to decrease subclinical repeated end organ ischemia during dialysis. However, complications such as increased interdialytic weight gain and thirst due to sodium excess have prevented widespread use of sodium profiling. Evidence suggest that different sodium profiling techniques may lead to different clinical results, and preferring sodium balance neutral sodium profiling may mitigate adverse effects related to sodium overload. However, evidence is lacking on the long-term clinical outcomes of different sodium profiling methods. Optimal method of sodium profiling as well as the utility of sodium/ultrafiltration profiling in routine practice await further clinical investigation.

Epidemiology of nursing home dialysis patients-A hidden population

Introduction

Dialysis patients are often discharged from hospitals to skilled nursing facilities (SNFs), but little has been published about their natural history.

Methods

Using electronic medical record data, we conducted a retrospective cohort study of nursing home patients treated with in‐SNF hemodialysis from January 1, 2018 through June 20, 2020 within a dialysis organization across eight states. A dialytic episode began with the first in‐SNF dialysis and was ended by hospitalization, death, transfer, or cessation of treatment. The clinical characteristics and natural history of these patients and their dialytic episodes are described.

Findings

Four thousand five hundred and ten patients experienced 9274 dialytic episodes. Dialytic episodes had a median duration of 18 days (IQR: 8–38) and were terminated by a hospitalization n = 5747 (62%), transfer n = 2638 (28%), death n = 568 (6%), dialysis withdrawal n = 129 (1.4%), recovered function n = 2 (0.02%), or other cause n = 6 (0.06%). Increased patient mortality was associated with advancing age, low serum creatinine, albumin, or sodium, and low pre‐dialytic systolic blood pressure (sBP). U‐shaped relationships to mortality were observed for intradialytic hypotension frequency and for post‐ > pre‐hemodialysis sBP frequency. Prescription of dialysis five times weekly in the first 2 weeks was associated with better survival in the first 90 days (HR 0.77, CI 0.62–0.96; p < 0.02).

Discussion

Provision of in‐SNF dialysis by an external dialysis organization enables discharge from the acute care setting for appropriate treatment with increased nursing contact time in an otherwise under‐resourced environment. SNF ESRD patient clinical characteristics and outcomes are extensively characterized for the first time.