Outcomes after the long interdialytic break: implications for the dialytic prescription

10 tips on how to manage severe arrhythmia in haemodialysis patients

Cardiovascular disease, particularly life-threatening ventricular arrhythmias and sudden cardiac death (SCD), remains the leading cause of death among haemodialysis (HD) patients, with an alarmingly higher incidence compared with the general population. By addressing key risk factors such as electrolyte imbalances, fluid overload and ultrafiltration rates, focusing on practical interventions and incorporating multidisciplinary care, clinicians can significantly reduce the risk of fatal arrhythmias. Here we propose 10 practical tips to guide clinicians in managing severe arrhythmias in HD patients. Each tip provides actionable insights for identifying high-risk individuals, with an emphasis on prevention and multidisciplinary care.

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.

Predictive value of heart rate variability on long-term mortality in end-stage kidney disease on hemodialysis

Autonomic disturbance is common in end-stage kidney disease (ESKD). Heart rate variability (HRV) is a useful tool to assess autonomic function. We aimed to evaluate the predictive value of HRV on all-cause mortality and explore the proper timing of HRV assessment. This prospective cohort study enrolled 163 ESKD on hemodialysis patients from April-December 2018. HRV measurements were recorded ten minutes before hemodialysis, four hours during hemodialysis, and ten minutes after hemodialysis. Clinical parameters and all-cause mortality were recorded. Cox-proportional hazard regression was used for statistical analysis. After a median follow up of 40 months, 37 (22.7%) patients died. Post-dialysis HRV parameters including higher very low frequency (VLF) (hazard ratio [HR], 0.881; 95%confidence interval [CI], 0.828-0.937; p<0.001), higher normalized low frequency (nLF) (HR, 0.950; 95%CI, 0.917-0.984; p = 0.005) and higher LF/HF ratio (HR, 0.232; 95%CI, 0.087-0.619; p = 0.004) were the independent predictors associated with lower risk for all-cause mortality. Higher post-dialysis normalized high frequency (nHF) increased risk of mortality (HR, 1.051; 95%CI, 1.015-1.089; p = 0.005). HRV parameters at pre-dialysis and during dialysis were not predictive for all-cause mortality. The area under receiver operating characteristic curve (AuROC) of VLF for survival was highest compared to other HRV parameters at post-dialysis period (AuROC 0.71; 95% CI; 0.62-0.79; p<0.001). In conclusion, post-dialysis HRV parameters predicted all-cause mortaliy in ESKD. VLF measured at post-dialysis exhibited best predictive value for survival in chronic hemodialysis patients.

Hurricanes and Mortality among Patients Receiving Dialysis

BACKGROUND

Hurricanes are severe weather events that can disrupt power, water, and transportation systems. These disruptions may be deadly for patients requiring maintenance dialysis. We hypothesized that the mortality risk among patients requiring maintenance dialysis would be increased in the 30 days after a hurricane.

METHODS

Patients registered as requiring maintenance dialysis in the United States Renal Data System who initiated treatment between January 1, 1997 and December 31, 2017 in one of 108 hurricane-afflicted counties were followed from dialysis initiation until transplantation, dialysis discontinuation, a move to a nonafflicted county, or death. Hurricane exposure was determined as a tropical cyclone event with peak local wind speeds ≥64 knots in the county of a patient's residence. The risk of death after the hurricane was estimated using time-varying Cox proportional hazards models.

RESULTS

The median age of the 187,388 patients was 65 years (IQR, 53-75) and 43.7% were female. There were 27 hurricanes and 105,398 deaths in 529,339 person-years of follow-up on dialysis. In total, 29,849 patients were exposed to at least one hurricane. Hurricane exposure was associated with a significantly higher mortality after adjusting for demographic and socioeconomic covariates (hazard ratio, 1.13; 95% confidence interval, 1.05 to 1.22). The association persisted when adjusting for seasonality.

CONCLUSIONS

Patients requiring maintenance dialysis have a higher mortality risk in the 30 days after a hurricane.

Urgent-start peritoneal dialysis: Association with outcomes

The majority of end-stage kidney disease (ESKD) patients start dialysis without adequate pre-dialysis planning. Of these patients, the vast majority initiate in-centre haemodialysis using a central venous catheter (ICHD-CVC). A minority utilise urgent-start peritoneal dialysis (USPD), whereby a peritoneal dialysis catheter is placed and used for dialysis without the usual 2-4-week waiting period. In this multicentre, retrospective study of adult patients initiating dialysis during 2018, we compared outcomes among patients utilising these two dialysis initiation routes. Patients who initiated dialysis via ICHD-CVC were matched 1:1 to patients who utilised USPD on the basis of aetiology of ESKD, race, diabetes status and insurance type. Hospitalisation and mortality were evaluated from dialysis initiation through the first of death, transplant, loss to follow-up or study end (30 June 2019). Outcomes were compared using models adjusted for age and sex. A total of 717 USPD patients were matched to ICHD-CVC patients. During follow-up, USPD patients were hospitalised at a rate of 1.21 admissions/patient-year (pt-yr) versus 1.51 admissions/pt-yr for ICHD-CVC. This corresponded to a 24% lower rate of hospitalisation among USPD patients (adjusted incidence rate ratio 0.76, 95% confidence interval [CI] 0.65-0.88). Mortality rates were 0.08 and 0.11 deaths/pt-yr among USPD patients and ICHD-CVC patients, respectively (adjusted hazard ratio 0.84, 95% CI 0.62, 1.15). These findings suggest that more widespread adoption of USPD may be beneficial among patients with limited pre-dialysis planning.

Home versus In-Center Dialysis and Day of the Week Hospitalization: A Cohort Study

Background

The dialysis treatment day after the 2-day interdialytic interval (Monday/Tuesday) is associated with a heightened risk of hospitalization for patients on in-center hemodialysis (ICHD). In this national cohort study, we sought to characterize hospitalizations by day of the week for patients receiving ICHD, home HD (HHD), and peritoneal dialysis (PD) and to identify whether there were differences in the probability of a Monday/Tuesday admission for each modality type.

Methods

Patients on maintenance dialysis in Canada were analyzed from 2005 to 2014 using the Canadian Organ Replacement Register. Patients on hemodialysis were categorized as those receiving ICHD, HHD, frequent ICHD, or frequent HHD (the latter two included short daily and nocturnal HD). Hospitalizations were attributed to the previous treatment if they occurred within 30 days of a treatment change. Differences in the proportion of patients experiencing a Monday/Tuesday admission with all other days of the week were compared using a generalized linear model with binomial distribution and reported using adjusted odds ratios (OR) with 95% CIs.

Results

Overall, 27,430 individuals experienced 111,748 hospitalization episodes. Rates per 1000 patient days were 3.76, 2.98, 2.71, 2.16, and 2.13 for each of frequent ICHD, ICHD, PD, HHD, and frequent HHD, respectively. Compared with those on ICHD, only patients receiving frequent HHD (OR, 0.89; 95% CI, 0.81 to 0.97) and PD (OR, 0.95; 95% CI, 0.93 to 0.97) had a lower odds of experiencing a Monday/Tuesday admission. The OR was lower when restricted to hospitalization episodes for cardiovascular reasons comparing frequent HHD with ICHD (OR, 0.68; 95% CI, 0.48 to 0.96).

Conclusion

In this nationally representative cohort, we identified that the probability of a Monday/Tuesday admission was lower for frequent HHD and PD compared with ICHD, most notably for hospitalizations due to cardiovascular causes. Gaining a better understanding of the reasons behind this observation may help to develop future strategies to reduce overall and cause-specific hospitalization for patients receiving dialysis.

Benefits and risks of frequent or longer haemodialysis: weighing the evidence

Although the ability of individuals with end-stage renal disease to maintain body homoeostasis is equally impaired during all weekdays, conventional haemodialysis (HD) treatment is scheduled thrice weekly, containing two short and one long interdialytic interval. This intermittent nature of HD and the consequent fluctuations in volume, metabolic parameters and electrolytes have long been hypothesized to predispose to complications. Large observational studies link the first weekday with an increased risk of cardiovascular morbidity and mortality. Several schemes of frequent and/or longer, home or in-centre HD have been introduced, aiming to alleviate the above risks by both increasing total dialysis duration and reducing the duration of interdialytic intervals. Observational studies in this field have non-uniform results, showing that enhanced frequency in home (but not in-centre) HD is associated with reduced mortality. Evidence from the randomized Daily and Nocturnal Trials of the Frequent HD Network suggest the opposite, showing mortality benefits with in-centre daily but not with home nocturnal dialysis. Secondary analyses of these trials indicate that daily and nocturnal schedules do not have equal effects on intermediate outcomes. Alternative schemes, such as thrice weekly in-centre nocturnal HD or every-other-day HD, seem to also offer improvements in several intermediate endpoints, but need further testing with randomized trials. This review summarizes the effects of frequent and/or longer HD methods on hard and intermediate outcomes, attempting to provide a balanced overview of the field.

Outcomes of major trauma among patients with chronic kidney disease and receiving dialysis in Nova Scotia: a retrospective analysis

Background

The risk of death and complications after major trauma in patients with chronic kidney disease (CKD) is higher than in the general population, but whether this association holds true among Canadian trauma patients is unknown.

Objectives

To characterize patients with CKD/receiving dialysis within a regional major trauma cohort and compare their outcomes with patients without CKD.

Methods

All major traumas requiring hospitalization between 2006 and 2017 were identified from a provincial trauma registry in Nova Scotia, Canada. Trauma patients with stage ≥3 CKD (estimated glomerular filtration rate <60 mL/min/1.73 m²) or receiving dialysis were identified by cross-referencing two regional databases for nephrology clinics and dialysis treatments. The primary outcome was in-hospital mortality; secondary outcomes included hospital/intensive care unit (ICU) length of stay (LOS) and ventilator-days. Cox regression was used to adjust for the effects of patient characteristics on in-hospital mortality.

Results

In total, 6237 trauma patients were identified, of whom 4997 lived within the regional nephrology catchment area. CKD/dialysis trauma patients (n=101; 28 on dialysis) were older than patients without CKD (n=4896), with higher rates of hypertension, diabetes, and cardiovascular disease, and had increased risk of in-hospital mortality (31% vs 11%, p<0.001). No differences were observed in injury severity, ICU LOS, or ventilator-days. After adjustment for age, sex, and injury severity, the HR for in-hospital mortality was 1.90 (95% CI 1.33 to 2.70) for CKD/dialysis compared with patients without CKD.

Conclusion

Independent of injury severity, patients without CKD/dialysis have significantly increased risk of in-hospital mortality after major trauma.

The impact of the Christmas holiday effect on interdialytic weight gain in hemodialysis patients: A multicenter observational retrospective cohort study

INTRODUCTION

The 3-day interdialytic interval (IDI) is associated with high interdialytic weight gain (IDWG), but little is known about the effect of public or religious holidays on IDWG. Consequently, we evaluated the impact of the "Christmas holiday effect" on IDWG of hemodialysis patients.

METHODS

A retrospective cohort study of adult hemodialysis patients (over 18 years) was conducted across five dialysis units in Australia. Demographic and clinical data were collected from electronic medical records. IDWG was established for three time points; regular 3-day IDI, 2-day IDI preceding the Christmas holiday and a 3-day IDI that included the Christmas holiday. Paired t-tests and logistic regression were used to compare differences in mean IDWG before and after the Christmas holiday and to examine factors associated with high IDWG, respectively.

FINDINGS

Two hundred and fifty-two patients, 69% of whom were male, with mean (SD) age of 65.4 ± 15.3 years, were studied. Most had end-stage kidney disease due to diabetes (44%), and they had been on hemodialysis for a median of 25.5 (IQR, 60-10) months. There was a significant increase in absolute IDWG (MD 0.21 kg, 95% CI -0.07 to 0.36; P = 0.004) and relative IDWG (MD 0.3%, 95% CI 0.10-0.40; P = 0.01) after the holiday 3-day IDI compared with the regular 3-day IDI. Older age (OR 0.12; 95% CI 0.02-0.55) and a unit increase in hemoglobin (OR 0.94; 95% CI 0.89-0.99) were associated with lower odds of high relative IDWG while speaking a language other than English increased the odds for high relative IDWG (OR 5.03; 95% CI 1.12-22.65).

CONCLUSION

Absolute and relative IDWG increased significantly after the Christmas holiday. Individualizing dialysis needs may improve outcomes for these patients.

Relation of Lean Body Mass and Muscle Performance to Serum Creatinine Concentration in Hemodialysis Patients

INTRODUCTION

Serum creatinine concentration is an important uremic marker and predictor of survival in dialysis patients. This cross-sectional case-control study was made to quantitatively describe the relation between lean body mass (LBM), physical performance measures, and serum creatinine values.

METHODS

Ninety hemodialysis patients and 106 controls were measured by bioimpedance spectroscopy, handgrip strength, sit-to-stand test, and biochemical serum tests. Univariate and multivariate general linear models were used to analyze quantitative relations.

RESULTS

At univariate regression LBM accounted for 13.6% variability of serum creatinine concentration. In adjusted analyses with age, height, and body mass, LBM persisted as the only significant predictor of midweek predialysis serum creatinine concentration. Physical performance measures handgrip strength and sit-to-stand performance did not improve prediction of serum creatinine. With addition of serum urea concentration and residual diuresis the predictive value of the regression model improved to account for 45% of serum creatinine variability. Each kg of LBM was associated with 7.7 μmol/l increase in creatinine concentration (95% CI 3.4-12.1, p=0.001).

CONCLUSION

Bioimpedance derived LBM has a significant linear relation with predialysis serum creatinine concentrations. Hereby described quantitative relation should help clinicians to better evaluate observed creatinine concentrations of hemodialysis patients when bioimpedance derived LBM is available.

Characterization of deficits across the spectrum of motor abilities in dialysis patients and the impact of sarcopenic overweight and obesity

BACKGROUND & AIMS

Physical performance deficits in kidney failure predict mortality and quality of life. We aimed to quantify deficits in multiple motor abilities, investigate associations of lean and fat tissue content with test results and analyzed performance of sarcopenic individuals with adipose tissue excess.

METHODS

Ninety hemodialysis patients and 140 healthy controls performed 6-minute walk test, gait speed measurement, sit-to-stand and time up and go tests, upper extremity handgrip and tapping tests, Stork balance and forward bend flexibility tests. Human Activity Profile questionnaire was used to assess habitual activity. Body composition was measured by bioimpedance analysis.

RESULTS

Relative performance deficit of dialysis patients in age, sex, height and comorbidity adjusted estimated marginal means was largest for balance and flexibility (-52 and -33%), followed by lower extremity deficits in sit-to-stand, time up and go and 6-minute walk tests (-29, -19 and -15%, respectively), p < 0.05 for all comparisons. Upper extremity performance was less affected. Lean tissue index associated significantly positively with five and fat tissue index associated significantly negatively with two out of nine tests. Sarcopenic overweight and obese individuals exhibited significant deficits mainly in lower extremity tests with worse composite lower extremity score when compared to other categories of body composition.

CONCLUSIONS

Patients with hemodialysis treated kidney failure have largest functional deficits in balance, flexibility and lower extremity functions. Lean and fat mass associate oppositely with physical performance measures and individuals at unfavorable extremes of these indices express significantly impaired lower extremity functions.

Ambulatory aortic blood pressure, wave reflections and pulse wave velocity are elevated during the third in comparison to the second interdialytic day of the long interval in chronic haemodialysis patients

BACKGROUND

Increased arterial stiffness and aortic blood pressure (BP) are independent predictors of cardiovascular outcomes in end-stage renal disease. The 3-day interdialytic interval is associated with elevated risk of cardiovascular morbidity and mortality in haemodialysis. This study investigated differences in ambulatory aortic BP and arterial stiffness between the second and third day of the long interdialytic interval.

METHODS

Ambulatory BP monitoring with Mobil-O-Graph monitor (IEM, Stolberg, Germany) was performed in 55 haemodialysis patients during a 3-day interval. Mobil-O-Graph records oscillometric brachial BP and pulse waves and calculates aortic BP and augmentation index (AIx) as measure of wave reflections, and pulse wave velocity (PWV) as measure of arterial stiffness.

RESULTS

Ambulatory aortic systolic blood pressure (SBP) and diastolic blood pressure (DBP) were higher during the third versus second interdialytic day (123.6 ± 17.0 versus 118.5 ± 17.1 mmHg, P < 0.001; 81.5 ± 11.8 versus 78 ± 11.9 mmHg, P < 0.001, respectively). Similar differences were noted for brachial BP. Ambulatory AIx and PWV were also significantly increased during the third versus second day (30.5 ± 9.9 versus 28.8 ± 9.9%, P < 0.05; 9.6 ± 2.3 versus 9.4 ± 2.3 m/s, P < 0.001, respectively). Differences between Days 2 and 3 remained significant when day-time and night-time periods were compared separately. Aortic SBP and DBP, AIx and PWV showed gradual increases from the end of dialysis session onwards. Interdialytic weight gain was a strong determinant of the increase in the above parameters.

CONCLUSIONS

This study showed significantly higher ambulatory aortic BP, AIx and PWV levels during the third compared with the second interdialytic day. These findings support a novel pathway for increased cardiovascular risk during the third interdialytic day in haemodialysis.

Ambulatory recording of wave reflections and arterial stiffness during intra- and interdialytic periods in patients treated with dialysis

BACKGROUND AND OBJECTIVES

Wave reflections and arterial stiffness are independent cardiovascular risk factors in ESRD. Previous studies in this population included only static recordings before and after dialysis. This study investigated the variation of these indices during intra- and interdialytic intervals and examined demographic, clinical, and hemodynamic variables related to arterial function in patients undergoing hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Between February 2013 and May 2014, a total of 153 patients receiving maintenance hemodialysis in five dialysis centers of northern Greece underwent ambulatory BP monitoring with the newly introduced Mobil-O-Graph device (IEM, Stolberg, Germany) over a midweek dialysis session and the subsequent interdialytic period. Mobil-O-Graph is an oscillometric device that records brachial BP and pulse waves and estimates, via generalized transfer function, aortic BP, augmentation index (AIx) as a measure of wave reflections, and pulse wave velocity (PWV) as an index of arterial stiffness.

RESULTS

AIx was lower during dialysis than in the interdialytic period of dialysis-on day (Day 1) (mean±SD, 24.7%±9.7% versus 26.8%±9.4%; P<0.001). In contrast, PWV remained unchanged between these intervals (9.31±2.2 versus 9.29±2.3 m/sec; P=0.60). Both AIx and PWV increased during dialysis-off day (Day 2) versus the out-of-dialysis period of Day 1 (28.8%±9.8% versus 26.8%±9.4% [P<0.001] and 9.39±2.3 versus 9.29±2.3 m/sec [P<0.001]). Older age (odds ratio [OR], 1.09; 95% confidence interval [95% CI], 1.02 to 1.15), female sex (OR, 7.56; 95% CI, 1.64 to 34.81), diabetic status (OR, 8.84; 95% CI, 1.76 to 17.48), and higher mean BP (OR, 1.17; 95% CI, 1.09 to 1.27) were associated with higher odds of high AIx; higher heart rate was associated with lower odds (OR, 0.71; 95% CI, 0.63 to 0.80) of high AIx. Older age (OR, 2.04; 95% CI, 1.61 to 2.58) and higher mean BP (OR, 1.15; 95% CI, 1.05 to 1.27) were independent correlates of high PWV.

CONCLUSIONS

This study showed a gradual interdialytic increase in AIx, whereas PWV was only slightly elevated during Day 2. Future studies are needed to elucidate the value of these ambulatory measures for cardiovascular risk prediction in ESRD.

Pro: Should we move to more frequent haemodialysis schedules?

Most end-stage renal disease patients on maintenance haemodialysis follow the typical schedule of three sessions per week, and thus remain outside dialysis for two short intervals (∼2 days in duration) and for a longer interval (∼3 days) at the end of each week. This pattern was historically enforced more due to calendar logistics and less due to factors related to health and disease. Therefore, it is long hypothesized that the intermittent nature of haemodialysis and the consequent shifts and fluctuations in volume status and metabolic parameters during the dialysis-free periods may pre-dispose patients to several complications. Recent large-scale observational studies in haemodialysis patients link the first week-day (including the last hours of the long interval and the subsequent dialysis session) with increased risk of cardiovascular morbidity and mortality. Previous observational studies support that enhanced-frequency home haemodialysis is associated with reduced risk of all-cause mortality, while randomized studies suggest that short-daily or alternate-day in-centre haemodialysis offer improvements in left ventricular hypertrophy, blood pressure, phosphorous homeostasis and other intermediate end points when compared with conventional thrice-weekly in-centre haemodialysis. This article summarizes available evidence relating long inter-dialytic intervals with elevated cardiovascular risk, potential mechanisms for this association and the main benefits of more frequent dialytic modalities.