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

Different Interdialytic Intervals and Cardiorespiratory Fitness in Patients Undergoing Hemodialysis

Key Points

This is the first study exploring differences in cardiorespiratory fitness assessed with cardiopulmonary exercise testing between the 2-day and the 3-day interdialytic interval. The 3-day interdialytic interval was associated with further impaired cardiorespiratory fitness. This effect was predominantly driven by excess fluid accumulation during the extra interdialytic day.

Background

Long interdialytic interval in thrice-weekly hemodialysis is associated with excess cardiovascular and all-cause mortality risk. Impaired cardiorespiratory fitness is a strong predictor of mortality in hemodialysis. This study investigated differences in cardiorespiratory fitness assessed with cardiopulmonary exercise testing (CPET) between the end of the 2-day and the 3-day interdialytic interval.

Methods

A total of 28 hemodialysis patients, randomized in two different sequences of evaluation, underwent CPET and spirometry examination at the end of the 2-day and the 3-day intervals. The primary outcome was the difference in oxygen uptake at peak exercise (VO2peak [ml/kg per minute]) assessed with CPET. Volume status was assessed with interdialytic weight gain, lung ultrasound, bioimpedance spectroscopy, and inferior vena cava measurements. A total of 14 age-matched and sex-matched controls were also evaluated. Comparisons of changes in parameters of interest were performed with paired or independent t -tests or relevant nonparametric tests, as appropriate. Bivariate correlation analyses and generalized linear mixed models were used to examine associations between changes in CPET parameters and volume indices.

Results

Hemodialysis patients at the end of both 2-day and 3-day intervals presented lower values in all major CPET parameters than controls. VO2peak (ml/kg per minute) was significantly higher at the end of the 2-day than the 3-day interval (15.2±4.2 versus 13.6±2.8; P < 0.001); the results were similar for VO2peak (ml/min) (1188±257 versus 1074±224; P < 0.001) and VO2peak (% predicted) (58.9±9.2 versus 52.3±8.6; P < 0.001). Numerical but no statistically significant differences were detected in VO2 anaerobic threshold (ml/kg per minute) and VO2 anaerobic threshold (ml/min) between the two time points. Maximal work load (90.1±23.2 versus 79.3±25.1; P < 0.001), exercise duration, heart rate at peak exercise, and oxygen pulse also showed lower values at the end of the 3-day interval. Forced expiratory volume in 1-second levels were similar between the two evaluations. Generalized linear mixed model analysis, including interdialytic weight gain as random covariate, attenuated the observed differences in VO2peak (ml/kg per minute). Changes in bioimpedance spectroscopy–derived overhydration indexes were moderately correlated with changes of VO2peak (ml/kg per minute).

Conclusions

The 3-day interval was associated with further impairment of VO2 at peak exercise. This effect was predominantly driven by excess fluid accumulation during the extra interdialytic day.

Patients' perspectives of fluid management: A multicentre comparative study of home and incentre haemodialysis

BACKGROUND

There is increasing worldwide interest in person-centred care in haemodialysis and home haemodialysis (HHD). Intradialytic fluid management is a vital component of haemodialysis, and often a shared decision, yet patients' perspectives and experience of related decisions are largely unexplored.

OBJECTIVES

To explore the perspectives of patients receiving home or incentre haemodialysis (IHD), in relation to intradialytic fluid management.

DESIGN

A multicentre cross-sectional survey.

PARTICIPANTS

Eight hundred and thirty-nine patients receiving IHD and 99 patients receiving HHD, across six English renal units.

MEASUREMENTS

Self-reported measures of understanding, experiences and control of fluid management, and willingness to achieve target weight. An objective test of patients' ability to relate common signs and symptoms to fluid overload or excessive ultrafiltration.

RESULTS

Patients receiving HHD had greater knowledge than those receiving IHD (66.1% vs. 42.3%, p < 0.001) about causes of common signs and symptoms which remained when controlling for age, education and years since beginning haemodialysis. Patients receiving HHD felt more in control of and had greater self-reported adherence to fluid management (p < 0.01), yet knowledge gaps existed in both cohorts.

CONCLUSIONS

Greater patient knowledge and its practice in HHD may contribute to improved fluid balance and outcomes. Whilst patient selection may contribute towards these differences, the training patients receive when opting for HHD and subsequent experience are likely to be key contributing factors. Integrating aspects of education on fluid management from HHD training programmes should be considered in IHD, and further targeted, robust education remains an unmet need.

Characteristics, practices, and outcomes in a Belgian cohort of incident home hemodialysis patients: A 6-year experience

BACKGROUND

Home hemodialysis (HHD) remains underused in patients with kidney failure. Current literature on HHD mostly originates from non-European countries, making generalization difficult. The present study describes patients' profile and practice patterns from a Belgian HHD center, and assesses patient and technique survival and complications associated with HHD.

METHODS

We analyzed data from all our incident patients during a 6-year period. The patient's characteristics were summarized using descriptive statistics. Transition to another therapeutic modality, estimated using a risk model with death and transplantation as competing events, episodes of respite cares and hospitalizations, and access complications were analyzed.

RESULTS

Eighty patients (mean age: 47 years; male: 64%) met the inclusion criteria. Fifty-one percent of patients initiated dialysis with a central venous catheter (CVC) and 96% were not assisted. Arterio-venous fistula (AVF) cannulation was performed using buttonhole technique. Standard-frequent HD (47%) and short-frequent low-flow dialysate HD (34%) were mostly used at HHD initiation. Cumulative incidences of technique failure and death were 15%, 24%, and 32% at 1, 2, and 5 years. Incidence rates for respite dialysis and hospitalizations were 2.39 and 0.54 per patient-year of HHD. In comparison with AVF, incidence rate ratios of overall access complications and access-related infections for CVC were 4.3 (95% CI: 3.1-6, p < 0.01) and 4.4 (95% CI: 2.1-10, p < 0.01), respectively. Buttonhole cannulation was complicated by 0.26 (95% CI: 0.15-0.46) infections per 1000 AVF-days.

CONCLUSIONS

This present study provides important information about patient's profile and practice patterns and safety in a cohort of 80 incident Belgian HHD patients, with encouraging techniques and patient survival.

Understanding the low take-up of home-based dialysis through a shared decision-making lens: a qualitative study

OBJECTIVES

To explore how people with chronic kidney disease who are pre-dialysis, family members and healthcare professionals together navigate common shared decision-making processes and to assess how this impacts future treatment choice.

DESIGN

Coproductive qualitative study, underpinned by the Making Good Decisions in Collaboration shared decision-model. Semistructured interviews with a purposive sample from February 2019 - January 2020. Interview data were analysed using framework analysis. Coproduction of logic models/roadmaps and recommendations.

SETTING

Five Welsh kidney services.

PARTICIPANTS

95 participants (37 patients, 19 family members and 39 professionals); 44 people supported coproduction (18 patients, 8 family members and 18 professionals).

FINDINGS

Shared decision-making was too generic and clinically focused and had little impact on people getting onto home dialysis. Preferences of where, when and how to implement shared decision-making varied widely. Apathy experienced by patients, caused by lack of symptoms, denial, social circumstances and health systems issues made future treatment discussions difficult. Families had unmet and unrecognised needs, which significantly influenced patient decisions. Protocols containing treatment hierarchies and standards were understood by professionals but not translated for patients and families. Variation in dialysis treatment was discussed to match individual lifestyles. Patients and professionals were, however, defaulting to the perceived simplest option. It was easy for patients to opt for hospital-based treatments by listing important but easily modifiable factors.

CONCLUSIONS

Shared decision-making processes need to be individually tailored with more attention on patients who could choose a home therapy but select a different option. There are critical points in the decision-making process where changes could benefit patients. Patients need to be better educated and their preconceived ideas and misconceptions gently challenged. Healthcare professionals need to update their knowledge in order to provide the best advice and guidance. There needs to be more awareness of the costs and benefits of the various treatment options when making decisions.

Assessment of Exercise Intolerance in Patients with Pre-Dialysis CKD with Cardiopulmonary Function Testing: Translation to Everyday Practice

BACKGROUND

Chronic kidney disease (CKD) is often characterized by increased prevalence of cardiovascular risk factors and increased incidence of cardiovascular events and death. Reduced cardiovascular reserve and exercise intolerance are common in patients with CKD and are associated with adverse outcomes.

SUMMARY

The gold standard for identifying exercise limitation is cardiopulmonary exercise testing (CPET). CPET provides an integrative evaluation of cardiovascular, pulmonary, hematopoietic, neuropsychological, and metabolic function during maximal or submaximal exercise. It is useful in clinical setting for differentiation of the causes of exercise intolerance, risk stratification, and assessment of response to relevant treatments. A number of recent studies have used CPET in patients with pre-dialysis CKD, aiming to assess the cardiovascular reserve of these individuals, as well as the effect of interventions such as exercise training programs on their functional capacity. This review provides an in-depth description of CPET methodology and an overview of studies that utilized CPET technology to assess cardiovascular reserve in patients with pre-dialysis CKD. Key Messages: CPET can delineate multisystem changes and offer comprehensive phenotyping of factors determining overall cardiovascular risk. Potential clinical applications of CPET in CKD patients range from objective diagnosis of exercise intolerance to preoperative and long-term risk stratification and providing intermediate endpoints for clinical trials. Future studies should delineate the association of CPET indexes, with cardiovascular and respiratory alterations and hard outcomes in CKD patients, to enhance its diagnostic and prognostic utility in this population.

Association Between Implementation Of Novel Therapies And Improved Survival In Patients Starting Hemodialysis: The Swedish Renal Registry 2006-2015

BACKGROUND

The recent years have witnessed significant therapeutic advances for patients on hemodialysis. We evaluated temporal changes in treatments practices and survival rates among incident hemodialysis patients.

METHODS

Observational study of patients initiating hemodialysis in Sweden 2006-2015. Trends of hemodialysis-related practices, medications, and routine laboratory biomarkers were evaluated. The incidence of death and major cardiovascular events (MACE) across calendar years were compared against the age-sex-matched general population. Via Cox regression, we explored whether adjustment for implementation of therapeutic advances modified observed survival and MACE risks.

RESULTS

Among 6,612 patients, age and sex were similar, but the burden of co-morbidities increased over time. The proportion of patients receiving treatment by hemodiafiltration, >3 sessions/week, lower ultrafiltration rate, and working fistulas increased progressively, as did use of non-calcium phosphate binders, cinacalcet, and vitamin D3. The standardized 1-year mortality decreased from 13.2% in 2006/07 to 11.1% in 2014/15. The risk of death decreased by 6% (HR 0.94, 95% CI 0.90-0.99) every two years, and the risk of MACE by 4% (HR 0.96; 0.92-1.00). Adjustment for changes in treatment characteristics abrogated these associations (HR 1.00; 0.92-1.09 for death and 1.00; 0.94-1.06 for MACE). Compared with the general population, the risk of death declined from 6 times higher 2006/2007 [standardized incidence rate ratio, sIRR 6.0 (5.3-6.9)], to 5.6 higher 2014/15 [sIRR 5.57 (4.8-6.4)].

CONCLUSIONS

Gradual implementation of therapeutic advances over the last decade was associated with a parallel reduction in short-term risk of death and MACE among hemodialysis patients.

A comparative study of ambulatory central hemodynamics and arterial stiffness parameters in peritoneal dialysis and hemodialysis patients

BACKGROUND

Ambulatory pulse-wave velocity (PWV), augmentation pressure, and augmentation index (AIx) are associated with increased cardiovascular events and death in hemodialysis. The intermittent nature of hemodialysis generates a distinct ambulatory pattern, with a progressive increase of augmentation pressure and AIx during the interdialytic interval. No study so far has compared the ambulatory course of central hemodynamics and PWV between peritoneal dialysis and hemodialysis patients.

METHODS

Thirty-eight patients under peritoneal dialysis and 76 patients under hemodialysis matched in a 1 : 2 ratio for age, sex and dialysis vintage underwent 48-h ambulatory blood pressure (BP) monitoring with the oscillometric Mobil-O-Graph device. Parameters of central hemodynamics [central SBP, DBP and pulse pressure (PP)], wave reflection [AIx, heart rate-adjusted AIx; AIx(75) and augmentation pressure] and PWV were estimated from the 48-h recordings.

RESULTS

Over the total 48-h period, no significant differences were observed between peritoneal dialysis and hemodialysis patients in mean levels of central SBP, DBP, PP, augmentation pressure, AIx, AIx(75) and PWV. However, patients under peritoneal dialysis and hemodialysis displayed different trajectories in all the above parameters over the course of the recording: in peritoneal dialysis patients no differences were noted in central SBP (125.0 ± 19.2 vs. 126.0 ± 17.8 mmHg, P = 0.25), DBP, PP, augmentation pressure (13.0 ± 6.8 vs. 13.7 ± 7. mmHg, P = 0.15), AIx(75) (25.9 ± 6.9 vs. 26.3 ± 7.8%, P = 0.54) and PWV (9.5 ± 2.1 vs. 9.6 ± 2.1 m/s, P = 0.27) from the first to the second 24-h period of the recording. In contrast, hemodialysis patients showed significant increases in all these parameters from the first to second 24 h (SBP: 119.5 ± 14.4 vs. 124.6 ± 15.0 mmHg, P < 0.001; augmentation pressure: 10.9 ± 5.3 vs. 13.1 ± 6.3 mmHg, P < 0.001; AIx(75): 24.7 ± 7.6 vs. 27.4 ± 7.9%, P < 0.001; PWV: 9.1 ± 1.8 vs. 9.3 ± 1.8 m/s, P < 0.001). Peritoneal dialysis patients had numerically higher levels than hemodialysis patients in all the above parameters during all periods studied and especially during the first 24-h.

CONCLUSION

Central BP, wave reflection indices and PWV during a 48-h recording are steady in peritoneal dialysis but gradually increase in hemodialysis patients. During all studied periods, peritoneal dialysis patients have numerically higher levels of all studied parameters, a fact that could relate to higher cardiovascular risk.