Incremental hemodialysis schedule at the start of renal replacement therapy

The "Rule of 4" ultrasound diagnostic criteria at 6 weeks postoperatively was more appropriate for clinical determination of arteriovenous fistula maturation

OBJECTIVE

The aim of this study was to investigate the timing of assessing the maturation of arteriovenous fistula (AVF) and the diagnostic efficacy of two ultrasound assessment criteria in determining the maturation of AVF.

METHODS

We collected clinical data on 227 patients with end-stage renal disease who were first diagnosed at our institution between February 1, 2023 and February 1, 2024, and were followed up regularly for 12 weeks post-AVF creation, with the diameter of the draining vein and the brachial artery volume flow (VF) recorded at 1 day, 2, 4, 6, 8, 10, and 12 weeks post-operation. We focused on the time of AVF maturation, and ultrasonographic diagnostic criteria 1 (the vein diameter was ≥4 mm, and the brachial artery VF was >500 mL/min, referred to as the "Rule of 4") and ultrasonographic diagnostic criteria 2 (the vein diameter was ≥5 mm, and the brachial artery VF was> 500 mL/min, referred to as the "Rule of 5") were used to evaluate the maturation of AVF. And compared with clinically maturation criteria to understand the correlation, consistency, and diagnostic efficacy.

RESULTS

1. The venous diameter and brachial artery VF of AVF showed an upward trend, and increased significantly in 1 day to 6 weeks postoperatively (p < .05),especially between 1 day and 2 weeks, while no significant difference in the increases at 6-12 weeks; 2. Logistic regression analysis showed that venous diameter (OR = 19.589 , 95% CI 1.560-245.979, p = .021) and brachial artery VF (OR = 1.024 , 95% CI 1.005-1.042, p = .011) at 6 weeks were the independent correlates affecting AVF maturation; and the optimal thresholds were 4.08 mm (sensitivity 88.10%, specificity 70.00%) and 472.50 mL/min (sensitivity 93.20%, specificity 84.00%), respectively; 3. Compared with clinical maturation, the two ultrasonographic diagnostic criteria at 6 weeks postoperatively were correlated with clinical maturation, and the specificity of both was 100%, with "Rule of 4" having a sensitivity of 79.66%, an accuracy of 84.14%, and a concordance kappa = 0.633, while "Rule of 5″ had a sensitivity of 31.63%, an accuracy of 46.69%, and a concordance kappa = 0.169; and the area under the ROC curve (AUC) for "Rule of 4″ was higher than that for "Rule of 5" (0.898 vs. 0.658, p < .001).

CONCLUSION

Six weeks postoperatively may be the best timing for an ultrasound assessment of AVF maturation, and the "Rule of 4" ultrasound assessment criteria was more suitable for clinical judgment of AVF maturation.

Incremental hemodialysis and vascular access complications: a 12-year experience in a hospital hemodialysis unit

BACKGROUND

Incremental hemodialysis (HD) is considered a valid alternative for patients with residual kidney function. Evidence concerning its effect on vascular access is scarce. We present our 12-year experience of an incremental hemodialysis program with the aim of evaluating survival and complications of arteriovenous fistula in these patients compared to the thrice-weekly scheme.

METHODS

From January 1st, 2006 to December 31st, 2017, 220 incident patients started hemodialysis, 132 (60%) of whom began hemodialysis with two sessions per week and 88 (40%) with three sessions per week. Demographic and clinical variables were assessed at the start of treatment. Data regarding arteriovenous fistula survival and complications were collected.

RESULTS

Both groups had similar baseline sociodemographic and clinical characteristics. A total of 188 (85%) patients were dialyzed with an arteriovenous fistula during follow-up. Eighty-three patients had one or more fistula complications, with no differences between incremental and conventional groups (p = 0.55). Fistula survival rates showed no significant difference between the two groups, whether analyzed from the date of fistula creation (Log Rank p = 0.810) or from the date of initial fistula cannulation (Log Rank p = 0.695).

CONCLUSIONS

We found no differences in arteriovenous fistula survival or complication rate between patients who started HD with an incremental versus a conventional treatment scheme. Randomized controlled clinical trials may be warranted to achieve a higher degree of evidence.

Knowledge and Practice of Incremental Hemodialysis: A Survey of Canadian Nephrologists

BACKGROUND

Incremental hemodialysis, a strategy to individualize dialysis prescription based on residual kidney function, may be associated with enhanced quality of life and decreased health care costs compared with conventional hemodialysis.

OBJECTIVE

We surveyed practicing Canadian nephrologists to assess knowledge, perceptions, and practice pattern on the use of incremental hemodialysis.

DESIGN/SETTING

We distributed a cross-sectional, web-based survey. We asked about incremental hemodialysis prescribing practices, including frequency of prescription, clinical factors used to determine suitability for treatment, and barriers to implementation. The survey was conducted from September 21 to October 30, 2020.

PARTICIPANTS

We distributed the survey to practicing Canadian nephrologists identified from a private membership list of the Canadian Society of Nephrology (CSN), as well as to nephrologists named on a publicly available national list of practicing Canadian nephrologists created from provincial College of Physician registries. These were samples of convenience.

METHODS

We conducted descriptive analysis of categorical data including frequencies for nominal variables and measures of central tendency (mean) and dispersion (standard deviation) for ordinal variables. We used chi-square analysis to identify association between participant and practice characteristics and their opinions and attitudes toward incremental dialysis. We used simple thematic analysis on free-text responses on questions regarding the prescription of incremental hemodialysis, focusing on age and baseline management of cardiac and noncardiac comorbidities.

RESULTS

The response rate was 35% (243/691). Most (138/211, 65%) of the participants prescribed incremental hemodialysis using an individualized approach at the nephrologist's discretion. Most participants (200/203, 98%) did not report any policy for implementation. Residual urine output was identified as the most important factor for eligibility (112/172, 65%), followed by electrolyte stability (76/172, 44%) and patient goals of care (69/117, 40%). Most participants agreed that dialysis prescriptions should take residual kidney function into consideration; however, 74% of the participants disagreed with a statement that there was strong evidence supporting incremental hemodialysis. Barriers identified included patient safety, patient acceptance of dose escalation, and logistics of scheduling. Despite these barriers, 82% of participants felt that that incremental hemodialysis is feasible with their current resources and 78% agreed that with specific criteria, it is a safe option.

LIMITATIONS

The generalizability of our study is limited by its response rate of 35%; however, this is comparable with typical response rates seen in electronic surveys. Most participants practice in an academic setting, which may have introduced bias to the results.

CONCLUSIONS

Despite the perception of limited evidence and a lack of guidance on implementation, incremental hemodialysis is frequently practiced by Canadian nephrologists. Barriers to implementation were identified, highlighting the need for research to guide practice.

Validation of a novel ultrasound Doppler monitoring device (earlybird) for measurements of volume flow rate in arteriovenous fistulas for hemodialysis

BACKGROUND

Controversy exists regarding surveillance of arteriovenous fistulas for hemodialysis to increase patency. A significant reduction in volume flow rate (VFR) should lead to diagnostic evaluation and eventually intervention. Several methods are available for VFR measurements, but all of them are associated with low reproducibility. VFR trend analysis is suggested as an improved solution. It is therefore a need to find user-friendly, cost and time-effective modalities. We present a novel Doppler ultrasound device (earlybird) which could bridge this gap. It includes an easy-to-use and light-weight single element transducer.

METHODS

In an experimental and clinical setting, we compared earlybird to duplex ultrasound to assess VFR. In a closed circuit of blood-mimicking fluid, 36 paired calculations of calibrated, duplex ultrasound and earlybird VFR was measured. In addition, 23 paired recordings of duplex ultrasound and earlybird VFR was measured in 16 patients with underarm arteriovenous fistulas. Pearson correlation, intraclass correlation coefficient, root-mean-square and Bland-Altman plots were analyzed.

RESULTS

Strong correlation (r = 0.991, p < 0.001), and excellent level of agreement (ICC = 0.970 (95% CI 0.932 - 0.985), p < 0.001) between earlybird and the calibrated VFR was found in the experimental setup. This was confirmed in the clinical setting, with a strong correlation (r = 0.781, p < 0.001) and moderate to good level of agreement (ICC = 0.750 (95% CI 0.502-0.885), p < 0.001) between earlybird and duplex ultrasound VFR measured at the arteriovenous fistulas outflow veins. In the Bland-Altman plot-analysis for the experimental setup, we found smaller limits of agreement, a smaller consistent and proportional bias, as well as greater accuracy of earlybird than DUS when compared to the calibrated VFR.

CONCLUSION

Earlybird is a feasible tool for VFR measurements and could be a future promising device for easy assessment and surveillance of AVF for hemodialysis.

Kidney supportive care: an update of the current state of the art of palliative care in CKD patients

Chronic kidney disease (CKD) has become a public health burden worldwide for its increasing incidence and prevalence, high impact on the health related quality of life (HRQoL) and life expectancy, and high personal and social cost. Patients with advanced CKD, in dialysis or not, suffer a burden from symptoms very similar to other chronic diseases and have a life span not superior to many malignancies. Accordingly, in recent years, renal palliative care has been recommended to be integrated in the traditional care delivered to this population. This research provides an updated overview on renal palliative care from the relevant literature.

How to manage catheter-related right atrial thrombosis: Our conservative approach

BACKGROUND

Catheter-related right atrial thrombosis is an underestimated, severe, and life-threatening complication of any type of central venous catheters. No clear-cut epidemiological data are available. Catheter-related right atrial thrombosis is often asymptomatic; however, it can lead to serious complications and death.

CASE SERIES

We report seven catheter-related right atrial thrombosis events occurred in five hemodialysis patients; two recurrences following primary treatment are included in the report, all of them managed with a conservative approach without catheter removal. Systemic anticoagulation (vitamin K antagonists), having a well-defined target of International Normalized Ratio of 2.5-3.0, combined with urokinase as a locking solution at the end of each hemodialysis session were the therapeutic strategy used in all patients. After the first month, the anticoagulation target was reduced to an International Normalized Ratio value of 1.5-2.0 and urokinase to a weekly administration. After sixth months, when no thrombus was identified at transthoracic echocardiographic examinations, the treatment was stopped. No bleeding complications were reported.

CONCLUSION

The combination therapy here described is safe, quick, and effective, achieving the goal of not removing catheters.

Initiating haemodialysis twice-weekly as part of an incremental programme may protect residual kidney function

BACKGROUND

Initiating twice-weekly haemodialysis (2×HD) in patients who retain significant residual kidney function (RKF) may have benefits. We aimed to determine differences between patients initiated on twice- and thrice-weekly regimes, with respect to loss of kidney function, survival and other safety parameters.

METHODS

We conducted a single-centre retrospective study of patients initiating dialysis with a residual urea clearance (KRU) of ≥3 mL/min, over a 20-year period. Patients who had 2×HD for ≥3 months during the 12 months following initiation of 2×HD were identified for comparison with those dialysed thrice-weekly (3×HD).

RESULTS

The 2×HD group consisted of 154 patients, and the 3×HD group 411 patients. The 2×HD patients were younger (59 ± 15 versus 62 ± 15 years: P = 0.014) and weighed less (70 ± 16 versus 80 ± 18 kg: P < 0.001). More were females (34% versus 27%: P = 0.004). Fewer had diabetes (25% versus 34%: P = 0.04) and peripheral vascular disease (PVD) (13% versus 23%: P = 0.008). Baseline KRU was similar in both groups (5.3 ± 2.4 for 2 × HD versus 5.1 ± 2.8 mL/min for 3 × HD: P = 0.507). In a mixed effects model correcting for between-group differences in comorbidities and demographics, 3×HD was associated with increased rate of loss of KRU and separation of KRU. In separate mixed effects models, group (2×HD versus 3×HD) was not associated with differences in serum potassium or phosphate, and the groups did not differ with respect to total standard Kt/V. Survival, adjusted for age, gender, weight, baseline KRU and comorbidity (prevalence of diabetes, cardiac disease, PVD and malignancy) was greater in the 2×HD group (hazard ratio 0.755: P = 0.044). In sub-analyses, the survival benefit was confined to women, and those of less than median bodyweight.

CONCLUSION

2×HD initiation as part of an incremental programme with regular monthly monitoring of KRU was safe and associated with a reduced rate of loss of RKF early after dialysis initiation and improved survival. Randomized controlled trials of this approach are indicated.

Initiating renal replacement therapy through incremental haemodialysis: Protocol for a randomized multicentre clinical trial

Background

Thrice-weekly haemodialysis is the usual dose when starting renal replacement therapy; however, this schedule is no longer appropriate since it does not consider residual renal function. Several reports have suggested the potential benefit of beginning haemodialysis less frequently and incrementally increasing the dose as the residual renal function decreases. However, all the data published so far are from observational studies. Thus, this clinical trial avoids any potential selection bias and will assess the possible benefits that have been observed in observational studies.

Methods/design

This report describes the study protocol of a randomized prospective multi-centre open-label clinical trial to evaluate whether starting renal replacement therapy with twice-weekly haemodialysis sessions preserves residual renal function better than the standard thrice-weekly regimen. We also explore other clinical parameters, such as concentrations of uremic toxins, dialysis doses, control of anaemia, removal of medium-weight uremic toxins, nutritional status, quality of life, hospital admissions and mortality. Only incident haemodialysis patients who can maintain a urea clearance rate KrU ≥ 2.5 mL/min/1.73 m² are eligible. Patient recruitment began on 1 January 2017 and will last for 2 years or until the required sample size has been recruited to ensure the established statistical power has been reached. The minimum follow-up period will be 1 year. Anuric patients with acute renal failure and patients who return to haemodialysis after a kidney transplant failure are excluded. It has been calculated that 44 patients should be recruited into each group to achieve a power of 80% in a two-sided comparison of means with a usual significance level of 0.05. A time-to-event analysis will estimate the probability of kidney function survival in both groups using the Kaplan–Meier method. Survival curves will be compared with log-rank tests. This survival analysis will be complemented with a proportional hazard model to estimate the hazard ratio of kidney function survival adjusted for any confounding factors. Analyses will be carried out in accordance with the intention-to-treat principle.

Discussion

The incremental initiation of dialysis may preserve residual renal function better than the conventional treatment, with similar or higher survival rates, as reported by observational studies. To our knowledge, this is the first clinical trial to evaluate whether initiating renal replacement therapy with twice-weekly haemodialysis sessions preserves residual renal function better than beginning with the standard thrice-weekly regimen.

Trial registration

ClinicalTrials.gov, NCT03302546. Registered on 5 October 2017.

Narrative Review of Incremental Hemodialysis

The prescription of hemodialysis (HD) in patients with incident end-stage kidney disease (ESKD) is fundamentally empirical. The abrupt transition from nondialysis chronic kidney disease (CKD) to thrice-weekly in-center HD of much the same dialysis intensity as in those with prevalent ESKD underappreciates the progressive nature of kidney disease whereby the decline in renal function has been gradual and ongoing-including at the time of HD initiation. Adjuvant pharmacologic treatment (i.e., diuretics, acid buffers, potassium binders), coupled with residual kidney function (RKF), can complement an initial HD regimen of lower intensity. Barriers to less intensive HD in incident ESKD include risk of inadequate clearance of uremic toxins due to variable and unexpected loss of RKF, lack of patient adherence to assessments of RKF or adjustment of HD intensity, increased burden for all stakeholders in the dialysis units, and negative financial repercussions. A stepped dialysis regimen with scheduled transition from time-delineated twice-weekly HD to thrice-weekly HD could represent an effective and safe strategy to standardize incremental HD in patients with CKD transitioning to early-stage ESKD. Patients' adherence and survival as well as other clinical outcomes should be rigorously evaluated in clinical trials before large-scale implementation of different incremental schedules of HD. This review discusses potential benefits of and barriers to alternative dialysis regimens in patients with incident ESKD, with emphasis on twice-weekly HD with pharmacologic therapy, and summarizes in-progress clinical trials of incremental HD schedules.

Factors affecting arteriovenous fistula dysfunction: A narrative review

Vascular access dysfunction is one of the most important causes of morbidity and mortality in haemodialysis patients, contributing to up to one third of hospitalisations and accounting for a significant amount of the health care costs of these patients. In the past decades, significant scientific advances in understanding mechanisms of arteriovenous fistula maturation and failure have contributed to an increase in the amount of research into techniques for creation and strategies for arteriovenous fistula dysfunction prevention and treatment, in order to improve patient care and outcomes. The aim of this review is to describe the pathogenesis of vascular access failure and provide a comprehensive analysis of the associated risk factors and causes of vascular access failure, in order to interpret possible future therapeutic approaches. Arteriovenous fistula failure is a multifactorial process resulting from the combination of upstream and downstream events with consequent venous neo-intimal hyperplasia and/or inadequate outward remodelling. Inflammation appears to be central in the biology of arteriovenous fistula dysfunction but important triggers still need to be revealed. Given the significant association of arteriovenous fistula failure and patient's prognosis, it is therefore imperative to further research in this area in order to improve prevention, surveillance and treatment, and ultimately patient care and outcomes.

IHDIP: a controlled randomized trial to assess the security and effectiveness of the incremental hemodialysis in incident patients

BACKGROUND

Most people who make the transition to renal replacement therapy (RRT) are treated with a fixed dose thrice-weekly hemodialysis réegimen, without considering their residual kidney function (RKF). Recent papers inform us that incremental hemodialysis is associated with preservation of RKF, whenever compared with conventional hemodialysis. The objective of the present controlled randomized trial (RCT) is to determine if start HD with one sessions per week (1-Wk/HD), it is associated with better patient survival and other safety parameters.

METHODS/DESIGN

IHDIP is a multicenter RCT experimental open trial. It is randomized in a 1:1 ratio and controlled through usual clinical practice, with a low intervention level and non-commercial. It includes 152 incident patients older than 18 years, with a RRF of ≥4 ml/min/1.73 m2, measured by renal clearance of urea (KrU). The intervention group includes 76 patients who will start with incremental HD (1-Wk/HD). The control group includes 76 patients who will start with thrice-weekly hemodialysis régimen. The primary outcome is assessing the survival rate, while the secondary outcomes are the morbidity rate, the clinical parameters, the quality of life and the efficiency.

DISCUSSION

This study will enable to know the number of sessions a patient should receive when starting HD, depending on his RRF. The potentially important clinical and financial implications of incremental hemodialysis warrant this RCT.

TRIAL REGISTRATION

U.S. National Institutes of Health, ClinicalTrials.gov . Number: NCT03239808 , completed 13/04/2017.

SPONSOR

Foundation for Training and Research of Health Professionals of Extremadura.