A systematic review of the effect of nocturnal hemodialysis on blood pressure, left ventricular hypertrophy, anemia, mineral metabolism, and health-related quality of life

Programmatic variation in home hemodialysis in Canada: results from a nationwide survey of practice patterns

Background

Over 40% of patients with end stage renal disease in the United States were treated with home hemodialysis (HHD) in the early 1970’s. However, this number declined rapidly over the ensuing decades so that the overwhelming majority of patients were treated in-centre 3 times per week on a 3-4 hour schedule. Poor outcomes for patients treated in this fashion led to a renewed interest in home hemodialysis, with more intensive dialysis schedules including short daily (SDHD) and nocturnal (NHD). The relative infancy of these treatment schedules means that there is a paucity of data on ‘how to do it’.

Objective

We undertook a systematic survey of home hemodialysis programs in Canada to describe current practice patterns.

Design

Development and deployment of a qualitative survey instrument.

Setting

Community and academic HHD programs in Canada.

Participants

Physicians, nurses and technologists.

Measurements

Programmatic approaches to patient selection, delivery of dialysis, human resources available, and follow up.

Methods

We developed the survey instrument in three phases. A focus group of Canadian nephrologists with expertise in NHD or SDHD discussed the scope the study and wrote questions on 11 domains. Three nephrologists familiar with all aspects of HHD delivery reviewed this for content validity, followed by further feedback from the whole group. Multidisciplinary teams at three sites pretested the survey and further suggestions were incorporated. In July 2010 we distributed the survey electronically to all renal programs known to offer HHD according to the Canadian Organ Replacement Registry.

We compiled the survey results using qualitative and quantitative methods, as appropriate.

Results

Of the academic and community programs that were invited to participate, 80% and 63%, respectively, completed the survey. We observed wide variation in programmatic approaches to patient recruitment, human resources, equipment, water, vascular access, patient training, dialysis prescription, home requirements, patient follow up, medications, and the approach to non-adherent patients.

Limitations

Cross-sectional survey, unable to link variation to outcomes. Competition for patients between HHD and home peritoneal dialysis means that case mix for HHD may also vary between centres.

Conclusions

There is wide variation between programs in all domains of HHD delivery in Canada. We plan further study of the extent to which differences in approach are related to outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/2054-3581-1-11) contains supplementary material, which is available to authorized users.

Effects of frequent hemodialysis on perceived caregiver burden in the Frequent Hemodialysis Network trials

BACKGROUND AND OBJECTIVES

Patients receiving hemodialysis often perceive their caregivers are overburdened. We hypothesize that increasing hemodialysis frequency would result in higher patient perceptions of burden on their unpaid caregivers.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In two separate trials, 245 patients were randomized to receive in-center daily hemodialysis (6 days/week) or conventional hemodialysis (3 days/week) while 87 patients were randomized to receive home nocturnal hemodialysis (6 nights/week) or home conventional hemodialysis for 12 months. Changes in overall mean scores over time in the 10-question Cousineau perceived burden scale were compared.

RESULTS

In total, 173 of 245 (70%) and 80 of 87 (92%) randomized patients in the Daily and Nocturnal Trials, respectively, reported having an unpaid caregiver at baseline or during follow-up. Relative to in-center conventional dialysis, the 12-month change in mean perceived burden score with in-center daily hemodialysis was -2.1 (95% confidence interval, -9.4 to +5.3; P=0.58). Relative to home conventional dialysis, the 12-month change in mean perceived burden score with home nocturnal dialysis was +6.1 (95% confidence interval, -0.8 to +13.1; P=0.08). After multiple imputation for missing data in the Nocturnal Trial, the relative difference between home nocturnal and home conventional hemodialysis was +9.4 (95% confidence interval, +0.55 to +18.3; P=0.04). In the Nocturnal Trial, changes in perceived burden were inversely correlated with adherence to dialysis treatments (Pearson r=-0.35; P=0.02).

CONCLUSION

Relative to conventional hemodialysis, in-center daily hemodialysis did not result in higher perceptions of caregiver burden. There was a trend to higher perceived caregiver burden among patients randomized to home nocturnal hemodialysis. These findings may have implications for the adoption of and adherence to frequent nocturnal hemodialysis.

Technique survival in home haemodialysis: a composite success rate and its risk predictors in a prospective longitudinal cohort from a tertiary renal network programme

BACKGROUND

Resurgence of interest in home haemodialysis (HHD) is, in part, due to emerging evidence of the benefits of extended HD regimens, which are most feasibly provided in the home setting. Although specific HHD therapy established at home such as nocturnal HD (NHD) has been reported from individual programmes, little is known about overall HHD success.

METHODS

The study included 166 patients who were accepted in the Manchester (UK) HHD training programme through liberal selection criteria. All patients were followed up prospectively until a switch to alternative modality, to include 4528 patient-months of follow-up and about 81 508 HHD sessions during an 8-year period (January 2004-December 2011). Twenty-four patients switched to an alternative modality during the period. Combined technique survival (HHDc) as a composite of training (HHDtr) and at home (HHDhome) was analysed and clinical predictors of HHD modality failure since the commencement of the programme were calculated using Cox regression analysis. Technology-related interruptions to dialysis over a 12-month period and patient-reported reasons for quitting the programme were analysed.

RESULTS

Technique survival at 1, 2 and 5 years was 90.2, 87.4, 81.5% (HHDc) and 98.4, 95.4 and 88.9% (HHDhome) when censored for training phase exits, death and transplantation. The combined HHDc modality switch rate is 1 in 192 patient-months of dialysis follow-up. Age >60 years, diabetes, cardiac failure, unit decrease in Hb and increasing score of age-adjusted Charlson--comorbidity index were significantly associated with technique failure. Significant clinical predictors of HHD technique failure in a multivariate model were diabetes (P = 0.002) and cardiac failure (P = 0.05). The majority (61%) switched to an alternative modality for non-medical reasons. The composite of operator error and mechanical breakdown resulting in temporary HHD technique failure was 0.7% per year.

CONCLUSIONS

HHD training and technique failure rate are low. Technical errors are infrequent too. Diabetes and cardiac failure are associated with significant risk of technique failure. Although absolute rates are low, training failure is proportionally quite significant, highlighting the importance of reporting the composite technique failure rate (to include early HHD training phase) in HHD programmes.

Readmission within 30 days of hospital discharge among children receiving chronic dialysis

BACKGROUND AND OBJECTIVES

The hospital admission rate for children receiving chronic dialysis has been increasing over the last decade. Approximately one third of patients with ESRD age 0-19 years are readmitted to the hospital within 30 days of discharge. The objective of this study was to examine hospital readmissions among a cohort of children receiving chronic dialysis to identify factors associated with higher rates of 30-day readmission.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

A retrospective cohort of index admissions was developed among chronic dialysis patients age 3 months to 17 years at free-standing children's hospitals reporting information to the Pediatric Hospital Information System between January 2006 and November 30, 2010, and followed until December 31, 2010. The primary outcome was any-cause 30-day readmission, and the secondary outcome was 30-day readmission for a cause similar to that of the index hospitalization.

RESULTS

In this cohort, 25% of hospital admissions were followed by a readmission within 30 days. Children older than 2 years of age had a lower odds of readmission (odds ratio [OR], 0.6; 95% confidence interval [95% CI], 0.5 to 0.8). Those receiving hemodialysis had a higher risk of readmission (OR, 1.2; 95% CI, 1.0 to 1.4), and admissions >14 days were also more likely to be followed by a readmission (OR, 1.5; 95% CI, 1.1 to 2.0). Approximately 50% of the readmissions were for a similar diagnosis as the index admission; however, the specific admitting diagnosis was not associated with readmission.

CONCLUSIONS

A significant number of admissions among children receiving long-term dialysis are followed by readmission within 30 days. Further investigation is required to reduce the high rate of readmissions in these children.

Economic evaluation of frequent home nocturnal hemodialysis based on a randomized controlled trial

Provider and patient enthusiasm for frequent home nocturnal hemodialysis (FHNHD) has been renewed; however, the cost-effectiveness of this technique is unknown. We performed a cost-utility analysis of FHNHD compared with conventional hemodialysis (CvHD; 4 hours three times per week) from a health payer perspective over a lifetime horizon using patient information from the Alberta NHD randomized controlled trial. Costs, including training costs, were obtained using microcosting and administrative data (CAN$2012). We determined the incremental cost per quality-adjusted life year (QALY) gained. Robustness was assessed using scenario, sensitivity, and probabilistic sensitivity analyses. Compared with CvHD (61% in-center, 14% satellite, and 25% home dialysis), FHNHD led to incremental cost savings (-$6700) and an additional 0.38 QALYs. In sensitivity analyses, when the annual probability of technique failure with FHNHD increased from 7.6% (reference case) to ≥19%, FHNHD became unattractive (>$75,000/QALY). The cost/QALY gained became $13,000 if average training time for FHNHD increased from 3.7 to 6 weeks. In scenarios with alternate comparator modalities, FHNHD remained dominant compared with in-center CvHD; cost/QALYs gained were $18,500, $198,000, and $423,000 compared with satellite CvHD, home CvHD, and peritoneal dialysis, respectively. In summary, FHNHD is attractive compared with in-center CvHD in this cohort. However, the attractiveness of FHNHD varies by technique failure rate, training time, and dialysis modalities from which patients are drawn, and these variables should be considered when establishing FHNHD programs.

Frequent hemodialysis: a critical review

Conventional, thrice-weekly hemodialysis (CHD) is the most commonly prescribed dialysis regimen. Despite widespread acceptance of CHD, long-term analyses of registry data have revealed an increased risk for mortality during the long 2-day interdialytic interval of thrice-weekly therapies. High mortality rates during this period suggest that there may be a role for more frequent HD in improving patient outcomes and survival through elimination of the long interdialytic period. Several regimens have been investigated including: short, daily HD, frequent nocturnal HD, and alternate-day HD. In this review, we provide an in-depth summary of current data comparing the effects of frequent and CHD modalities on survival, hospitalizations, vascular access complications, burden of therapy, quality of life, residual renal function, cardiovascular parameters, bone mineral metabolism, and anemia. Limitations of the data as well as the role of frequent dialysis in clinical practice are also discussed.

Survival comparison between intensive hemodialysis and transplantation in the context of the existing literature surrounding nocturnal and short-daily hemodialysis

Our contemporary paradigms of nocturnal and short-daily hemodialysis (NHD and SDHD) have their origins in the earliest era of dialysis care for end-stage renal disease. However, these therapies have received considerably more attention in recent years owing to an increasing body of literature, suggesting a myriad of benefits attributable to these intensive dialysis regimens compared with conventional thrice-weekly hemodialysis. Analyses suggest a survival benefit for NHD and SDHD versus traditional hemodialysis prescriptions, and it is in this context that survival comparisons between intensive dialysis and transplantation must be considered. This literature and its limitations are reviewed here.

Impact of frequent hemodialysis on anemia management: results from the Frequent Hemodialysis Network (FHN) Trials

BACKGROUND

The extent to which anemia management is facilitated by more frequent hemodialysis (HD) is controversial. We hypothesized as a preselected outcome that patients receiving HD six times (6×) compared with three times (3×) per week would require lower doses of erythropoietin-stimulating agents (ESA) and/or achieve higher blood hemoglobin (Hb) concentrations.

METHODS

Subjects enrolled in the Frequent Hemodialysis Network (FHN) daily and nocturnal trials were studied. As the primary outcome for anemia, the dose of ESAs was recorded at 4-month intervals and the monthly dose of intravenous iron (IV Fe) was reported. Serum iron, transferrin saturation and ferritin were measured at baseline and then at 4-month intervals, whereas Hb concentration was measured monthly.

RESULTS

There was no significant treatment effect in the 6× versus 3× treatment groups on logESA dose or the ratio of log of ESA dose to Hb concentration in either trial. In the daily trial, Hb concentrations increased significantly in the 6× versus 3× group, at Month 12 compared with baseline (0.3 g/dL; 95% CI: 0.05-0.58, P<0.021), but both groups had Hb concentrations in the usual target range. In the daily trial, the weekly logESA dose and the logESA dose to Hb concentration ratio tended to decline more in the 6× versus 3× group. This trend was not observed in the nocturnal trial. IV Fe doses were significantly lower in the 6× compared with the 3× group by Month 12 in the nocturnal trial, but not different in the daily trial.

CONCLUSIONS

In the FHN Daily and Nocturnal Trials, more frequent HD did not have a significant or clinically important effect on anemia management.

Nocturnal hemodialysis

Patients receiving conventional hemodialysis have high hospitalisation rates, poor quality of life and survival compared to the general population. Many centres around the world are providing longer hours of hemodialysis - short daily hemodialysis and nocturnal hemodialysis - with a view to improving patient survival and quality of life. Studies have shown that nocturnal haemodiaysis is more effective than conventional hemodialysis in clearing most small, middle and larger molecule toxins and suggest nocturnal dialysis enhances patient survival and quality of life. Concerns include patient acceptance, vascular access related complications and increased cost. The purpose of this review is to examine the advantages and drawbacks of nocturnal dialysis, with a focus on applicability to India where the renal physician has to face cultural and economic barriers, erratic power supply and poor water quality.

Daily ultrafiltration results in improved blood pressure control and more efficient removal of small molecules during hemodialysis

BACKGROUND

Although prior studies have shown that frequent hemodialysis (HD) can lead to improved control of dry weight in end-stage renal disease patients, there are no clinical studies examining whether this can improve blood pressure (BP) control and can also shorten the dialysis time needed to achieve satisfactory removal of small molecules. Several models of wearable dialysis systems are now under various stages of development. These devices present the possibility of hemodialyzing patients to their dry weights. We have built a prototype of a wearable ultrafiltration (UF) device that can provide daily UF. Apart from better fluid control, we hypothesize that separating HD from UF will result in better BP control, and adequate weekly small molecule removal could be achieved with a decreased duration of dialysis. We tested the hypothesis in current HD patients using conventional dialysis equipment.

METHODS

Thirteen patients were selected from a large urban HD center. The experimental period consisted of 4 weeks of daily UF (4 days/week of UF alone and 2 days/week of HD with UF). The duration of the HD sessions was increased by 15-30 min to maintain weekly standard Kt/V >2.0. The patients were then returned to their conventional 3 days/week of HD with UF and studied for 4 weeks. Predialysis BPs, interdialytic weight gains, and Kt/V results of the experimental and return periods were compared with those of the 3-month control period. No changes were made in antihypertensive or other medication during the study.

RESULTS

During the experimental period, mean arterial pressure decreased from 110 to 95 mm Hg (p < 0.001), systolic BP from 158 to 136 mm Hg (p < 0.001), while interdialytic weight gains were reduced from 3.25 to 1.21 liters (p < 0.0001). During the experimental period, weekly standard Kt/V of 2.16 was achieved in 8.24 h/week of HD, as compared to 11.14 h/week.

CONCLUSIONS

Volume control with daily UF results in improved BP control and, by separating the UF function from HD, adequate weekly standard Kt/V >2 can be achieved with twice weekly HD.

Effects of three times weekly eight-hour nocturnal hemodialysis on volume and nutritional status

BACKGROUND

This prospective cohort study compared the changes in body water composition and nutritional parameters measured with multifrequency bioimpedance analysis between 8-hour three times weekly nocturnal hemodialysis (NHD) and 4-hour conventional hemodialysis (CHD) patients.

PATIENTS AND METHODS

55 patients on CHD and 57 patients on NHD were included in the study. Multifrequency bioimpedance analysis was performed at baseline and at the 12th month. The primary outcomes of the study were changes in extracellular water (ECW), fat mass, dry lean mass and phase angle. Secondary outcomes of the study included changes in blood pressure and biochemical parameters related to nutrition and inflammation.

RESULTS

ECW/height values decreased in the NHD group, while they increased in the CHD group. Fat mass, dry lean mass, and serum albumin increased and high sensitive CRP decreased in the NHD group but did not change in the CHD group. When changes in parameters from baseline to the 12th month between the groups were compared, NHD was associated with improvement in volume parameter including ECW/height (difference -0.44 l/m, p < 0.001). Change in blood pressure was not different between the groups, however requirement for antihypertensive medication decreased from 26.5 to 8.5% in the NHD group (p = 0.002). NHD was also associated with increases in fat mass (difference 1.8 kg, p < 0.001), dry lean mass (difference 0.6 kg, p = 0.006), serum albumin (difference 0.19 g/dl, p < 0.001) and cholesterol (difference 18.8 mg, p < 0.001). Phase angle values decreased in the CHD group but did not change in the NHD group (difference between the groups 0.37°, p = 0.04).

CONCLUSION

This study revealed that longer HD facilitates volume control and improves nutritional status.

Managing cardiovascular risk in people with chronic kidney disease: a review of the evidence from randomized controlled trials

Cardiovascular disease is the leading cause of death and morbidity in people with chronic kidney disease (CKD) making measures to modify cardiovascular risk a clinical priority. The relationship between risk factors and cardiovascular outcomes is often substantially different in people with CKD compared with the general population, leading to uncertainty around pathophysiological mechanisms and the validity of generalizations from the general population. Furthermore, published reports of subgroup analyses from clinical trials have suggested that a range of interventions may have different effects in people with kidney disease compared with those with normal kidney function. There is a relative scarcity of randomized controlled trials (RCTs) conducted in CKD populations, and most such trials are small and underpowered. As a result, evidence to support cardiovascular risk modification measures for people with CKD is largely derived from small trials and post hoc analyses of RCTs conducted in the general population. In this review, we examine the available RCT evidence on interventions aimed at preventing cardiovascular events in people with kidney disease to identify beneficial treatments as well as current gaps in knowledge that should be a priority for future research.

Longer dialysis session length is associated with better intermediate outcomes and survival among patients on in-center three times per week hemodialysis: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND

Longer dialysis session length (treatment time, TT) has been associated with better survival among hemodialysis (HD) patients. The impact of TT on clinical markers that may contribute to this survival advantage is not well known.

METHODS

Using data from the international Dialysis Outcomes and Practice Patterns Study, we assessed the association of TT with clinical outcomes using both standard regression analyses and instrumental variable approaches. The study included 37,414 patients on in-center HD three times per week with prescribed TT from 120 to 420 min.

RESULTS

Facility mean TT ranged from 214 min in the USA to 256 min in Australia-New Zealand. Accounting for country effects, mortality risk was lower for patients with longer TT {hazard ratio for every 30 min: all-cause mortality: 0.94 [95% confidence interval (CI): 0.92-0.97], cardiovascular mortality: 0.95 (95% CI: 0.91-0.98) and sudden death: 0.93 (95% CI: 0.88-0.98)}. Patients with longer TT had lower pre- and post-dialysis systolic blood pressure, greater intradialytic weight loss, higher hemoglobin (for the same erythropoietin dose), serum albumin and potassium and lower serum phosphorus and white blood cell counts. Similar associations were found using the instrumental variable approach, although the positive associations of TT with weight loss and potassium were lost.

CONCLUSIONS

Favorable levels of a variety of clinical markers may contribute to the better survival of patients receiving longer TT. These findings support longer TT prescription in the setting of in-center, three times per week HD.

Effects of six versus three times per week hemodialysis on physical performance, health, and functioning: Frequent Hemodialysis Network (FHN) randomized trials

BACKGROUND AND OBJECTIVES

Relatively little is known about the effects of hemodialysis frequency on the disability of patients with ESRD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study examined changes in physical performance and self-reported physical health and functioning among subjects randomized to frequent (six times per week) compared with conventional (three times per week) hemodialysis in both the Frequent Hemodialysis Network daily (n=245) and nocturnal (n=87) trials. The main outcome measures were adjusted change in scores over 12 months on the short physical performance battery (SPPB), RAND 36-item health survey physical health composite (PHC), and physical functioning subscale (PF) based on the intention to treat principle.

RESULTS

Overall scores for SPPB, PHC, and PF were poor relative to population norms and in line with other studies in ESRD. In the Daily Trial, subjects randomized to frequent compared with conventional in-center hemodialysis experienced no significant change in SPPB (adjusted mean change of -0.20±0.19 versus -0.41±0.21, P=0.45) but experienced significant improvement in PHC (3.4±0.8 versus 0.4±0.8, P=0.009) and a relatively large change in PF that did not reach statistical significance. In the Nocturnal Trial, there were no significant differences among subjects randomized to frequent compared with conventional hemodialysis in SPPB (adjusted mean change of -0.92±0.44 versus -0.41±0.43, P=0.41), PHC (2.7±1.4 versus 2.1±1.5, P=0.75), or PF (-3.1±3.5 versus 1.1±3.6, P=0.40).

CONCLUSIONS

Frequent in-center hemodialysis compared with conventional in-center hemodialysis improved self-reported physical health and functioning but had no significant effect on objective physical performance. There were no significant effects of frequent nocturnal hemodialysis on the same physical metrics.

Optimal fluid control can normalize cardiovascular risk markers and limit left ventricular hypertrophy in thrice weekly dialysis patients

Increased hemodialysis frequency can make fluid overload easier to treat, although most patients are still treated thrice weekly. Chronic fluid overload is associated with left ventricular hypertrophy and elevated serum cardiac biomarkers, recognized as mortality risk factors. Serum cardiac troponin T (cTnT), N-terminal prohormone brain natriuretic peptide (NT-proBNP), left ventricular mass index by cardiac magnetic imaging, and ambulatory blood pressure was measured in 30 thrice weekly hemodiafiltration patients. Time-averaged fluid overload (TAFO) was quantified by bioimpedance spectroscopy. In the study group, left ventricular hypertrophy was found to be 26% by cardiac magnetic resonance. Ambulatory blood pressure was 130 mmHg (112-151) requiring a low equivalent dose of medication of 0.25 units (0-1). Significantly, lower levels of left ventricular mass index (P < 0.05) were associated in those patients with TAFO <1 L or NT-proBNP <1200 pg/mL or cTnT <0.1 ug/L. In the subgroups, 16 patients had normal cTnT (<0.03 ug/L), 16 patients had NT-proBNP <400 pg/mL, and 20 patients had TAFO <1 L. Nine patients had both cTnT <0.03 ug/L and NT-proBNP <400 pg/mL. Normally hydrated thrice-weekly hemodiafiltration patients can have cardiac biomarker and TAFO levels indistinguishable from the normal healthy population. Obtaining TAFO by bioimpedance monitoring can offer a practical alternative to serum cardiac biomarkers.

Determinants of left ventricular mass in patients on hemodialysis: Frequent Hemodialysis Network (FHN) Trials

BACKGROUND

An increase in left ventricular mass (LVM) is associated with mortality and cardiovascular morbidity in patients with end-stage renal disease.

METHODS AND RESULTS

The Frequent Hemodialysis Network (FHN) Daily Trial randomized 245 patients to 12 months of 6 times per week daily in-center hemodialysis or conventional hemodialysis; the FHN Nocturnal Trial randomized 87 patients to 12 months of 6 times per week nocturnal hemodialysis or conventional hemodialysis. The main cardiac secondary outcome was change in LVM. In each trial, we examined whether several predefined baseline demographic or clinical factors as well as change in volume removal, blood pressure, or solute clearance influenced the effect of frequent hemodialysis on LVM. In the Daily Trial, frequent hemodialysis resulted in a significant reduction in LVM (13.1 g; 95% CI, 5.0-21.3 g; P=0.002), LVM index (6.9 g/m(2); 95% CI, 2.4-11.3 g/m(2); P=0.003), and percent change in geometric mean of LVM (7.0%; 95% CI, 1.0%-12.6; P=0.02). Similar trends were noted in the Nocturnal Trial but did not reach statistical significance. In the Daily Trial, a more pronounced effect of frequent hemodialysis on LVM was evident among patients with left ventricular hypertrophy at baseline. Changes in LVM were associated with changes in blood pressure (conventional hemodialysis: R=0.28, P=0.01, daily hemodialysis: R=0.54, P<0.001) and were not significantly associated with changes in other parameters.

CONCLUSIONS

Frequent in-center hemodialysis reduces LVM. The benefit of frequent hemodialysis on LVM may be mediated by salutary effects on blood pressure. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00264758.

Effect of frequent or extended hemodialysis on cardiovascular parameters: a meta-analysis

BACKGROUND

Increased left ventricular (LV) mass is a risk factor for cardiovascular mortality in patients with chronic kidney failure. More frequent or extended hemodialysis (HD) has been hypothesized to have a beneficial effect on LV mass.

STUDY DESIGN

Meta-analysis.

SETTING & POPULATION

MEDLINE literature search (inception to April 2011), Cochrane Central Register of Controlled Trials and ClinicalTrials.gov using the search terms "short daily HD," "daily HD," "quotidian HD," "frequent HD," "intensive HD," "nocturnal HD," and "home HD."

SELECTION CRITERIA FOR STUDIES

Single-arm cohort studies (with pre- and post-study evaluations) and trials examining the effect of frequent or extended HD on cardiac morphology and function and blood pressure parameters. Studies of hemofiltration, hemodiafiltration, and peritoneal dialysis were excluded.

INTERVENTION

Frequent (2-8 hours, >3 times weekly) or extended (>4 hours, 3 times weekly) HD compared with conventional (≤4 hours, 3 times weekly) HD.

OUTCOMES

Absolute changes in cardiac morphology and function, including LV mass index (LVMI; primary) and blood pressure parameters (secondary).

RESULTS

We identified 38 single-arm studies, 5 crossover trials, and 3 randomized controlled trials. By meta-analysis of 23 study arms, frequent or extended HD significantly reduced LVMI from baseline (-31.2 g/m(2), 95% CI, -39.8 to -22.5; P < 0.001). The 3 randomized trials found a less pronounced net reduction in LVMI (-7.0 g/m(2); 95% CI, -10.2 to -3.7; P < 0.001). LV ejection fraction improved by 6.7% (95% CI, 1.6% to 11.9%; P = 0.01). Other cardiac morphologic parameters showed similar improvements. There also were significant decreases in systolic, diastolic, and mean blood pressure and mean number of antihypertensive medications.

LIMITATIONS

Paucity of randomized controlled trials.

CONCLUSIONS

Conversion from conventional to frequent or extended HD is associated with improvements in cardiac morphology and function, including LVMI and LV ejection fraction, respectively, and several blood pressure parameters, which collectively might confer long-term cardiovascular benefit. Trials with long-term clinical outcomes are needed.

Survival in daily home hemodialysis and matched thrice-weekly in-center hemodialysis patients

Frequent hemodialysis improves cardiovascular surrogates and quality-of-life indicators, but its effect on survival remains unclear. We used a matched-cohort design to assess relative mortality in daily home hemodialysis and thrice-weekly in-center hemodialysis patients between 2005 and 2008. We matched 1873 home hemodialysis patients with 9365 in-center patients (i.e., 1:5 ratio) selected from the prevalent population in the US Renal Data System database. Matching variables included first date of follow-up, demographic characteristics, and measures of disease severity. The cumulative incidence of death was 19.2% and 21.7% in the home hemodialysis and in-center patients, respectively. In the intention-to-treat analysis, home hemodialysis associated with a 13% lower risk for all-cause mortality than in-center hemodialysis (hazard ratio [HR], 0.87; 95% confidence interval [95% CI], 0.78-0.97). Cause-specific mortality HRs were 0.92 (95% CI, 0.78-1.09) for cardiovascular disease, 1.13 (95% CI, 0.84-1.53) for infection, 0.63 (95% CI, 0.41-0.95) for cachexia/dialysis withdrawal, 1.06 (95% CI, 0.81-1.37) for other specified cause, and 0.59 (95% CI, 0.44-0.79) for unknown cause. Findings were similar using as-treated analyses. We did not detect statistically significant evidence of heterogeneity of treatment effects in subgroup analyses. In summary, these data suggest that relative to thrice-weekly in-center hemodialysis, daily home hemodialysis associates with modest improvements in survival. Continued surveillance should strengthen inference about causes of mortality and determine whether treatment effects are homogeneous throughout the dialysis population.

Nocturnal hemodialysis: analysis following the Frequent Hemodialysis Network trial

The recently concluded Frequent Hemodialysis Network (FHN) trials have demonstrated some striking and unexpected results. Both the daily arm and the nocturnal arm of the trial clearly demonstrated that frequent (daily or nightly) dialysis reduced blood pressure, reduced the number of antihypertensive medications, and reduced serum phosphorous concentration. One of the major questions addressed by these studies was the extent to which left ventricular mass was reduced by frequent dialysis. While the daily FHN trial showed a clear effect of frequent dialysis to reduce left ventricular mass, the nocturnal FHN trial produced inconclusive results. These apparently contradictory results are probably influenced by inadequate power and the somewhat skewed patient selection in the nocturnal arm. Patients in the nocturnal FHN trial had a shorter time on dialysis prior to enrollment, and greater residual renal function than did patients in the daily FHN trial. From a general perspective, it appears that there is minimal difference in the effect on left ventricular mass between frequent daily dialysis and nocturnal dialysis. The FHN trial was not designed to determine the effects of frequent dialysis on mortality. The analyses of this question using retrospective data strongly suggest that frequent dialysis prolongs life. The nephrology community now has the task to develop new ways to deliver improved therapy to patients on dialysis. This task will be challenging as resources for health care are constrained. New approaches to the care of such patients will be needed to realize the important conceptual advances embedded in the results of the FHN trials.

An economic assessment model for in-center, conventional home, and more frequent home hemodialysis

More intensive and/or frequent hemodialysis may provide clinical benefits to patients with end-stage renal disease; however, these dialysis treatments are more convenient to the patients if provided in their homes. Here we created a standardized model, based on a systematic review of available costing literature, to determine the economic viability of providing hemodialysis in the home that arrays costs and common approaches for assessing direct medical and nonmedical costs. Our model was based on data from Australia, Canada, and the United Kingdom. The first year start-up costs for all hemodialysis modalities were higher than in subsequent years with modeled costs for conventional home hemodialysis lower than in-center hemodialysis in subsequent years. Modeled costs for frequent home hemodialysis was higher than both in-center and conventional home hemodialysis in the United Kingdom, but lower than in-center hemodialysis and higher than conventional home hemodialysis in Australia and Canada in subsequent years. The higher costs of frequent compared to conventional home hemodialysis were because of higher consumable usage due to dialysis frequency. Thus, our findings reinforce the conclusions of previous studies showing that home-based conventional and more frequent hemodialysis may provide clinical benefit at reasonable costs.

Cardiac and vascular structure and function parameters do not improve with alternate nightly home hemodialysis: an interventional cohort study

BACKGROUND

Nightly extended hours hemodialysis may improve left ventricular hypertrophy and function and endothelial function but presents problems of sustainability and increased cost. The effect of alternate nightly home hemodialysis (NHD) on cardiovascular structure and function is not known.

METHODS

Sixty-three patients on standard hemodialysis (SHD: 3.5-6 hours/session, 3-5 sessions weekly) converted to NHD (6-10 hours/session overnight for 3-5 sessions weekly). 2Dimensional transthoracic echocardiography and ultrasound measures of brachial artery reactivity (BAR), carotid intima-media thickness (CIMT), total arterial compliance (TAC) and augmentation index (AIX) were performed post dialysis at baseline and 18-24 months following conversion to NHD. In 37 patients, indices of oxidative stress: plasma malonyldialdehyde (MDA) and anti-oxidant enzymes: catalase (CAT), glutathione peroxidase (GPX) and superoxide dismutase (SOD) activity and total antioxidant status (TAS) were measured at baseline, 3 and 6 months.

RESULTS

Left ventricular mass index (LVMI) remained stable. Despite significant derangement at baseline, there were no changes in diastolic function measures, CIMT, BAR and TAC. AIX increased. Conversion to NHD improved bone mineral metabolism parameters and blood pressure control. Interdialytic weight gains increased. No definite improvements in measures of oxidative stress were demonstrated.

CONCLUSIONS

Despite improvement in uremic toxin levels and some cardiovascular risk factors, conversion to an alternate nightly NHD regimen did not improve cardiovascular structure and function. Continuing suboptimal control of uremic toxins and interdialytic weight gains may be a possible explanation. This study adds to the increasing uncertainty about the nature of improvement in cardiovascular parameters with conversion to intensive hemodialysis regimens. Future randomized controlled trials will be important to determine whether increases in dialysis session duration, frequency or both are most beneficial for improving cardiovascular disease whilst minimizing costs and the impact of dialysis on quality of life.

The effects of frequent nocturnal home hemodialysis: the Frequent Hemodialysis Network Nocturnal Trial

Prior small studies have shown multiple benefits of frequent nocturnal hemodialysis compared to conventional three times per week treatments. To study this further, we randomized 87 patients to three times per week conventional hemodialysis or to nocturnal hemodialysis six times per week, all with single-use high-flux dialyzers. The 45 patients in the frequent nocturnal arm had a 1.82-fold higher mean weekly stdKt/V(urea), a 1.74-fold higher average number of treatments per week, and a 2.45-fold higher average weekly treatment time than the 42 patients in the conventional arm. We did not find a significant effect of nocturnal hemodialysis for either of the two coprimary outcomes (death or left ventricular mass (measured by MRI) with a hazard ratio of 0.68, or of death or RAND Physical Health Composite with a hazard ratio of 0.91). Possible explanations for the left ventricular mass result include limited sample size and patient characteristics. Secondary outcomes included cognitive performance, self-reported depression, laboratory markers of nutrition, mineral metabolism and anemia, blood pressure and rates of hospitalization, and vascular access interventions. Patients in the nocturnal arm had improved control of hyperphosphatemia and hypertension, but no significant benefit among the other main secondary outcomes. There was a trend for increased vascular access events in the nocturnal arm. Thus, we were unable to demonstrate a definitive benefit of more frequent nocturnal hemodialysis for either coprimary outcome.

Impact of short daily hemodialysis on restless legs symptoms and sleep disturbances

BACKGROUND AND OBJECTIVES

Restless legs syndrome (RLS) and sleep disturbances are common among in-center hemodialysis patients and are associated with increased morbidity/mortality.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The FREEDOM study is an ongoing prospective cohort study investigating the benefits of home short daily hemodialysis (SDHD) (6 times/week). In this interim report, we examine the long-term effect of SDHD on the prevalence and severity of RLS, as measured by the International Restless Legs Syndrome (IRLS) Study Group rating scale, and sleep disturbances, as measured by the Medical Outcomes Study sleep survey.

RESULTS

235 participants were included in this report (intention-to-treat cohort), of which 127 completed the 12-month follow-up (per-protocol cohort). Mean age was 52 years, 55% had an arteriovenous fistula, and 40% suffered from RLS. In the per-protocol analysis, among patients with RLS, the mean IRLS score improved significantly at month 12, after adjustment for use of RLS-related medications (18 versus 11). Among patients with moderate-to-severe RLS (IRLS score ≥15), there was an even greater improvement in the IRLS score (23 versus 13). The intention-to-treat analysis yielded similar results. Over 12 months, there was decline in the percentage of patients reporting RLS (35% versus 26%) and those reporting moderate-to-severe RLS (59% versus 43%). There was a similar and sustained 12-month improvement in several scales of the sleep survey, after adjustment for presence of RLS and use of anxiolytics and hypnotics.

CONCLUSIONS

Home SDHD is associated with long-term improvement in the prevalence and severity of RLS and sleep disturbances.

Blood pressure management in hemodialysis: what have we learned?

PURPOSE OF REVIEW

To review recent developments in the field of hypertension in hemodialysis patients.

RECENT FINDINGS

Despite the fact that hypertension is the most common complication of end-stage kidney disease, no evidence-based blood pressure (BP) targets exist for hemodialysis patients. There is growing evidence that outcomes are better predicted by out-of-office BP values, such as home or ambulatory BP monitoring. Intradialytic hypertension is associated with increased risk of death or hospitalization, and is probably mediated by volume overload. BP management should focus on volume control: dry weight 'probing' is well tolerated and effective in lowering BP, as are other strategies that minimize expansion of the extracellular fluid volume, such as avoidance of hypernatric dialysate. We discuss each of these issues in our review.

SUMMARY

Modest advances in the understanding of hypertension have occurred in the past 2 years. Clinical trials that focus on BP targets and treatment choices are essential to guide future practice.

Design and rationale of health-related quality of life and patient-reported outcomes assessment in the Frequent Hemodialysis Network trials

BACKGROUND

End-stage renal disease patients experience significant impairments in health-related quality of life (HRQOL). Testing various strategies to improve patient HRQOL in multicenter clinical trials, such as the Frequent Hemodialysis Network (FHN) trials is vitally important.

AIMS

The aim of this paper is to describe the design and conduct of HRQOL and patient-reported outcomes (PRO) assessment in the FHN trials.

METHODS

In the FHN trials, HRQOL was examined as a multidimensional concept, and the SF-36 RAND Physical Health Composite score was one of the co-primary outcomes. The instruments completed to assess HRQOL included the Medical Outcomes Study Short Form SF-36, Health Utilities Index 3, Sleep Problems Index, Beck Depression Inventory and feeling thermometer. These instruments have been shown to have high reliability, validity and responsiveness to change in the end-stage renal disease population. Additional items evaluating PRO including sexual function, time to recovery after dialysis and patients' self-perceived burden to caregiver were also assessed. All questionnaires were administered by trained interviewers using computer-assisted telephone interviewing to ensure blinding and minimizing selection bias. Interim analysis reveals that these instruments can be used to collect a comprehensive set of HRQOL measures with minimal patient burden.

CONCLUSIONS

Accurate measurement of HRQOL and PRO can help us test whether hemodialysis interventions improve the health and well-being of this compromised patient population. We have shown that a comprehensive set of HRQOL measures can be centrally collected through telephone interviews in a blinded fashion, in a way that is well tolerated with minimum respondent burden.

Interdialytic hypertension-an update

The reference standard for diagnosing hypertension among hemodialysis patients is 44-hour interdialytic ambulatory blood pressure (BP) recording. However, a more practical way to diagnose and manage hypertension is to measure home BP over the interdialytic interval. In contrast to pre- and postdialysis BP recordings, measurements of BP performed outside the dialysis unit correlate with the presence of left ventricular hypertrophy and directly and strongly with all-cause mortality. Hypervolemia that is not clinically obvious is the most common treatable cause of hypertension among patients with end-stage renal disease; thus, volume control should be the initial therapy to treat hypertension in most hemodialysis patients. To diagnose hypervolemia, continuous blood volume monitoring is emerging as an effective and simple technique. Reducing dietary and dialysate sodium is an often overlooked strategy to improve BP control. Although definitive randomized trials that show cardiovascular benefits of BP lowering among hypertensive hemodialysis have not been performed, emerging evidence suggests that lowering BP might reduce cardiovascular events. The treatment should be guided by BP obtained outside the dialysis unit because predialysis and postdialysis BP are quite variable and agree poorly with measurements obtained outside the dialysis unit. Although the appropriate level to which BP should be lowered remains elusive, current data suggest that interdialytic ambulatory systolic BP should be lowered to <130 mm Hg and averaged home systolic BP to <140 mm Hg. Antihypertensive drugs will be required by most patients receiving thrice weekly dialysis for 4 hours. Beta blockers, dihydropyridine calcium blockers, and agents that block the renin-angiotensin system appear to be effective in lowering BP in these patients.

In-center hemodialysis six times per week versus three times per week

BACKGROUND

In this randomized clinical trial, we aimed to determine whether increasing the frequency of in-center hemodialysis would result in beneficial changes in left ventricular mass, self-reported physical health, and other intermediate outcomes among patients undergoing maintenance hemodialysis.

METHODS

Patients were randomly assigned to undergo hemodialysis six times per week (frequent hemodialysis, 125 patients) or three times per week (conventional hemodialysis, 120 patients) for 12 months. The two coprimary composite outcomes were death or change (from baseline to 12 months) in left ventricular mass, as assessed by cardiac magnetic resonance imaging, and death or change in the physical-health composite score of the RAND 36-item health survey. Secondary outcomes included cognitive performance; self-reported depression; laboratory markers of nutrition, mineral metabolism, and anemia; blood pressure; and rates of hospitalization and of interventions related to vascular access.

RESULTS

Patients in the frequent-hemodialysis group averaged 5.2 sessions per week; the weekly standard Kt/V(urea) (the product of the urea clearance and the duration of the dialysis session normalized to the volume of distribution of urea) was significantly higher in the frequent-hemodialysis group than in the conventional-hemodialysis group (3.54±0.56 vs. 2.49±0.27). Frequent hemodialysis was associated with significant benefits with respect to both coprimary composite outcomes (hazard ratio for death or increase in left ventricular mass, 0.61; 95% confidence interval [CI], 0.46 to 0.82; hazard ratio for death or a decrease in the physical-health composite score, 0.70; 95% CI, 0.53 to 0.92). Patients randomly assigned to frequent hemodialysis were more likely to undergo interventions related to vascular access than were patients assigned to conventional hemodialysis (hazard ratio, 1.71; 95% CI, 1.08 to 2.73). Frequent hemodialysis was associated with improved control of hypertension and hyperphosphatemia. There were no significant effects of frequent hemodialysis on cognitive performance, self-reported depression, serum albumin concentration, or use of erythropoiesis-stimulating agents.

CONCLUSIONS

Frequent hemodialysis, as compared with conventional hemodialysis, was associated with favorable results with respect to the composite outcomes of death or change in left ventricular mass and death or change in a physical-health composite score but prompted more frequent interventions related to vascular access. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; ClinicalTrials.gov number, NCT00264758.).

Baseline characteristics of participants in the Frequent Hemodialysis Network (FHN) daily and nocturnal trials

BACKGROUND

The annual mortality rate for maintenance hemodialysis patients in the United States is unacceptably high at 15%-20%. In 2004, we initiated the Frequent Hemodialysis Network (FHN) clinical trials. This report presents baseline characteristics of FHN Trial participants and compares them with hemodialysis patients tracked in US Renal Data System (USRDS) data.

STUDY DESIGN

2 separate randomized clinical trials.

SETTINGS & PARTICIPANTS

FHN includes 332 patients with chronic kidney disease requiring long-term dialysis therapy enrolled in 2 separate randomized clinical trials. The FHN Daily Trial (245 randomly assigned participants) was designed to compare outcomes of 6-times-weekly in-center daily hemodialysis (1.5-2.75 h/session) with conventional 3-times-weekly in-center hemodialysis. The FHN Nocturnal Trial (87 randomly assigned participants) was designed to compare outcomes of 6-times-weekly home nocturnal (6-8 h/session) with conventional 3-times-weekly hemodialysis. USRDS data include 338,109 incident and prevalent long-term hemodialysis patients from the calendar year 2007.

RESULTS

Participants in both trials were on average younger than the average hemodialysis patient in the United States (Daily Trial, 50.4 years; P < 0.001; Nocturnal Trial, 52.8 years; P < 0.001). Compared with USRDS data, whites were under-represented in the Daily Trial (36% vs 55%; P < 0.001), whereas Hispanics were under-represented in the Nocturnal Trial and over-represented in the Daily Trial (0% vs 28%; P < 0.001). In addition, there were more fistulas and fewer catheters in the Daily Trial (61% and 20%, respectively; P < 0.001 for both) and fewer grafts and more catheters in the Nocturnal Trial (10% and 44%, respectively; P < 0.005 for both).

LIMITATIONS

Clinical trial exclusion criteria and patient willingness to participate limit comparisons with the USRDS.

CONCLUSIONS

FHN participants were younger and the racial composition for each study was different from the racial composition of the aggregate US dialysis population. Catheters for vascular access were more common in FHN Nocturnal Trial participants.

Novel Trends in Haemodialysis: Where Are We Heading?

The mortality and morbidity of end-stage renal failure patients undergoing conventional thrice weekly in-centre haemodialysis remain alarmingly high despite continuing advances in haemodialysis technologies and improvements in clinical care. Home haemodialysis continues to be under-utilised in many parts of the world despite the reported benefits. Alternative haemodialysis regimens including longer and/or more frequent dialysis (e.g. nocturnal haemodialysis and short daily haemodialysis), haemodiafiltration and the use of high flux dialysers have become more widespread in recent years as nephrologists struggle to improve the dismal survival figures. Whilst most of the encouraging data have come from observational studies, many randomised controlled trials which will provide more robust data are already underway. This review aims to provide a concise update of the recent and novel trends in haemodialysis. Key words: Haemodiafiltration, High flux dialysis, Home haemodialysis, Nocturnal haemodialysis, Short daily haemodialysis

More intensive hemodialysis

Clinical outcomes have not improved substantially for patients treated with conventional thrice weekly hemodialysis. More intensive hemodialysis regimens, including daily short dialysis, and nocturnal prolonged dialysis show promise to improve morbidity and mortality. Published studies and trials underway examining these therapies are reviewed.

The cost of starting and maintaining a large home hemodialysis program

Home extended hours hemodialysis improves some measurable biological and quality-of-life parameters over conventional renal replacement therapies in patients with end-stage renal disease. Published small studies evaluating costs have shown savings in terms of ongoing operating costs with this modality. However, all estimates need to include the total costs, including infrastructure, patient training, and maintenance; patient attrition by death, transplantation, technique failure; and the necessity of in-center dialysis. We describe a comprehensive funding model for a large centrally administered but locally delivered home hemodialysis program in British Columbia, Canada that covered 122 patients, of which 113 were still in the program at study end. The majority of patients performed home nocturnal hemodialysis in this 2-year retrospective study. All training periods, both in-center and in-home dialysis, medications, hospitalizations, and deaths were captured using our provincial renal database and vital statistics. Comparative data from the provincial database and pricing models were used for costing purposes. The total comprehensive costs per patient-incorporating startup, home, and in-center dialysis; medications; home remodeling; and consumables-was $59,179 for years 2004-2005 and $48,648 for 2005-2006. The home dialysis patients required multiple in-center dialysis runs, significantly contributing to the overall costs. Our study describes a valid, comprehensive funding model delineating reliable cost estimates of starting and maintaining a large home-based hemodialysis program. Consideration of hidden costs is important for administrators and planners to take into account when designing budgets for home hemodialysis.

Intradialytic hypertension: a less-recognized cardiovascular complication of hemodialysis

Intradialytic hypertension, defined as an increase in blood pressure during or immediately after hemodialysis that results in postdialysis hypertension, has long been recognized to complicate the hemodialysis procedure, yet often is largely ignored. In light of recent investigations suggesting that intradialytic hypertension is associated with adverse outcomes, this review broadly covers the epidemiologic characteristics, prognostic significance, potential pathogenic mechanisms, prevention, and possible treatment of intradialytic hypertension. Intradialytic hypertension affects up to 15% of hemodialysis patients and occurs more frequently in patients who are older, have lower dry weights, are prescribed more antihypertensive medications, and have lower serum creatinine levels. Recent studies associated intradialytic hypertension independently with higher hospitalization rates and decreased survival. Although the pathophysiologic mechanisms of intradialytic hypertension are uncertain, it likely is multifactorial and includes subclinical volume overload, sympathetic overactivity, activation of the renin-angiotensin system, endothelial cell dysfunction, and specific dialytic techniques. Prevention and treatment of intradialytic hypertension may include careful attention to dry weight, avoidance of dialyzable antihypertensive medications, limiting the use of high-calcium dialysate, achieving adequate sodium solute removal during hemodialysis, and using medications that inhibit the renin-angiotensin-aldosterone system or decrease endothelin 1 levels. In summary, although intradialytic hypertension often is underappreciated, recent studies suggest that it should not be ignored. However, further work is necessary to elucidate the pathophysiologic mechanisms of intradialytic hypertension and its appropriate management and determine whether treatment of intradialytic hypertension can improve clinical outcomes.