Comparison between incremental and thrice‐weekly haemodialysis: Systematic review and meta‐analysis

Once-per-week haemodialysis in a financial crisis: Predictors of interdialytic weight gain

BACKGROUND

Several countries are experiencing challenges in maintaining standard haemodialysis services for people with kidney failure.

OBJECTIVE

This study aimed to investigate the health profile of people receiving haemodialysis and to identify factors associated with interdialytic weight gain.

DESIGN

A cross-sectional study.

PARTICIPANTS

A total of 166 adults with kidney failure and receiving haemodialysis for at least 3 months were included.

MEASUREMENTS

A structured chart audit form collected, demographic and haemodialysis treatment characteristics, recent biochemical and haematological results, and prescribed treatment regimens from clinical records. Data were analysed descriptively. Odds ratios (OR) were calculated to identify independent risk factors for interdialytic weight gain.

RESULTS

Mean age was 52 years (SD = 12.5), over half were male (60.2%, n = 100), and most were receiving 4 h of haemodialysis once per week (87.3%, n = 145). Approximately half (51.8%, n = 86) had an interdialytic weight gain >2%. Being female (OR = 3.39; 95% CI, 1.51-7.61), increased comorbidities (OR = 1.50; 95% CI, 1.22-1.84) and having BMI outside of the normal range (overweight/obese [OR = 8.49; 95% CI, 3.58-20.13] or underweight [OR = 4.61; 95% CI, 1.39-15.31]) were independent risk factors for increased interdialytic weight gain.

CONCLUSION

Most patients were receiving 4 h of haemodialysis once per week although only modest alterations in potassium, phosphate, and fluid status were observed. Understanding the patient profile and predictors of interdialytic weight gain will inform the development of self-management interventions to optimise clinician support.

Incremental versus conventional haemodialysis in end-stage kidney disease: a systematic review and meta-analysis

Background

Appropriate dialysis prescription in the transitional setting from chronic kidney disease to end-stage kidney disease is still challenging. Conventional thrice-weekly haemodialysis (HD) might be associated with rapid loss of residual kidney function (RKF) and high mortality. The benefits and risks of incremental HD compared with conventional HD were explored in this systematic review and meta-analysis.

Methods

We searched MEDLINE, Scopus and Cochrane Central Register of Controlled Trials up to April 2023 for studies that compared the impacts of incremental (once- or twice-weekly HD) and conventional thrice-weekly HD on cardiovascular events, RKF, vascular access complications, quality of life, hospitalization and mortality.

Results

A total of 36 articles (138 939 participants) were included in this meta-analysis. The mortality rate and cardiovascular events were similar between incremental and conventional HD {odds ratio [OR] 0.87 [95% confidence interval (CI)] 0.72-1.04 and OR 0.67 [95% CI 0.43-1.05], respectively}. However, hospitalization and loss of RKF were significantly lower in patients treated with incremental HD [OR 0.44 (95% CI 0.27-0.72) and OR 0.31 (95% CI 0.25-0.39), respectively]. In a sensitivity analysis that included studies restricted to those with RKF or urine output criteria, incremental HD had significantly lower cardiovascular events [OR 0.22 (95% CI 0.08-0.63)] and mortality [OR 0.54 (95% CI 0.37-0.79)]. Vascular access complications, hyperkalaemia and volume overload were not statistically different between groups.

Conclusions

Incremental HD has been shown to be safe and may provide superior benefits in clinical outcomes, particularly in appropriately selected patients. Large-scale randomized controlled trials are required to confirm these potential advantages.

Multicentre registry analysis of incremental peritoneal dialysis incidence and associations with patient outcomes

BACKGROUND

Incremental peritoneal dialysis (PD) is increasingly advocated to reduce treatment burden and costs, with potential to better preserve residual kidney function. Global prevalence of incremental PD use is unknown and use in Australia and New Zealand has not been reported.

METHODS

Binational registry analysis including incident adult PD patients in Australia and New Zealand (2007-2017), examining incidence of and outcomes associated with incremental PD (first recorded PD exchange volume <42 L/week (incremental) vs. ≥42 L/week (standard)).

RESULTS

Incremental PD use significantly increased from 2.7% of all incident PD in 2007 to 11.1% in 2017 (mean increase 0.84%/year). Duration of incremental PD use was 1 year or less in 67% of cases. Male sex, Aboriginal and Torres Strait Islander (ATSI) or Māori ethnicities, age 45-59 years, medical comorbidities or treatment at a centre with low use of automated PD or icodextrin was associated with lower incidence of incremental PD use. Low body mass index and higher estimated glomerular filtration rate was associated with higher incidence. After accounting for patient and centre variables, commencing PD with an incremental prescription was associated with reduced peritonitis risk (adjusted hazard ratio 0.73, 95% confidence interval (CI) 0.61-0.86).When kidney transplantation and death were considered as competing risks, the association between incremental PD and peritonitis was not significant (sub-hazard ratio [SHR] 0.91, 95%CI 0.71-1.17, p = 0.5), however cumulative incidence of 30-day transfer to haemodialysis was lower in those receiving incremental PD (SHR 0.73, 95%CI 0.56-0.94, p = 0.01). There was no association between incremental PD and death.

CONCLUSIONS

Incremental PD use is increasing in Australia and New Zealand and is not associated with patient harm.

Australian Workshops on Patients' Perspectives on Hemodialysis and Incremental Start

Introduction

Most patients with kidney failure commence and continue hemodialysis (HD) thrice weekly. Incremental initiation (defined as HD less than thrice weekly) is increasingly considered to be safe and less burdensome, but little is known about patients' perspectives. We aimed to describe patients' priorities and concerns regarding incremental HD.

Methods

Patients currently, previously, or soon to be receiving HD in Australia participated in two 90-minute online workshops to discuss views about HD focusing on incremental start and priorities for trial outcomes. Transcripts were analyzed using thematic analysis. Outcomes were ranked on the basis of the sum of participants' priority scores (i.e., single allocation of 3 points for most important, 2 for second, and 1 for third most important outcome).

Results

All 26 participants (1 caregiver and 25 patients) preferred an incremental HD approach. The top prioritized outcomes were quality of life (QOL) (56 points), residual kidney function (RKF) (27 points), and mortality (16 points). The following 4 themes underpinning outcome priorities, experience, and safety concerns were identified: (i) unpreparedness and pressure to adapt, (ii) disruption to daily living, (iii) threats to safety, and (iv) hope and future planning.

Conclusion

Patients with kidney failure preferred an incremental start to HD to minimize disruption to daily living and reduce the negative impacts on their education, ability to work, and family life. QOL was the most critically important outcome, followed by RKF and survival.

Incremental Versus Standard (Full-Dose) Peritoneal Dialysis

Incremental peritoneal dialysis (PD), defined as less than “standard dose” PD prescription, has a number of possible benefits, including better preservation of residual kidney function (RKF), reduced risk of peritonitis, lower peritoneal glucose exposure, lesser environmental impact, and reduced costs. Patients commencing PD are often new to kidney replacement therapy and possess substantial RKF, which may allow safe delivery of an incremental prescription, often in the form of lower frequency or duration of PD. This has the potential to help improve quality of life (QOL) and life participation through reducing time requirements and burden of treatment. Alternatively, incremental PD could potentially contribute to reduced small solute clearance, fluid overload, or patient reluctance to increase dialysis prescription when later needed. This review discusses the definition, rationale, uptake, potential advantages and disadvantages, and clinical trial evidence pertaining to the use of incremental PD.

A mixed-method feasibility study of a novel transitional regime of incremental haemodialysis: study design and protocol

Background

Incremental haemodialysis/haemodiafiltration (HD) may help reduce early mortality rates in patients starting HD. This mixed-method feasibility study aims to test the acceptability, tolerance and safety of a novel incremental HD regime, and to study its impact on parameters of patient wellbeing.

Method

We aim to enrol 20 patients who will commence HD twice-weekly with progressive increases in duration and frequency, achieving conventional treatment times over 15 weeks (incremental group). Participants will be followed-up for 6 months and will undergo regular tests including urine collections, bio-impedance analyses and quality-of-life questionnaires. Semi-structured interviews will be conducted to explore patients’ prior expectations from HD, their motivations for participation and experiences of receiving incremental HD. For comparison of safety and indicators of dialysis adequacy, a cohort of 40 matched patients who previously received conventional HD will be constructed from local dialysis records (historical controls).

Results

Data will be recorded on the numbers screened and proportions consented and completing the study (primary outcome). Incremental and conventional groups will be compared in terms of differences in blood pressure control, interdialytic weight changes, indicators of dialysis adequacy and differences in adverse and serious adverse events. In analyses restricted to incremental group, measurements of RRF, fluid load and quality-of-life during follow-up will be compared with baseline values. From patient interviews, a narrative description of key themes along with anonymised quotes will be presented.

Conclusion

Results from this study will address a significant knowledge gap in the prescription HD therapy and inform the development novel future therapy regimens.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10157-021-02072-1.

Lowering dialysis sessions duration may be dangerous

Dialysis session in less duration - either to give a better quality of life for the patient or to optimize the organization the dialysis institution - may have bad repercussions on the quality of the treatment and therefore the quality of life of the patient. According to the result of the publications listed in this work, we conclude that it is necessary to perform either longer sessions or more frequent treatments to limit the interval time between two sessions. As this is difficult to perform by the providers, we recommend to develop home dialysis to obtain the best result.

Hemodialysis Adequacy and Its Impact on Long-Term Patient Survival in Demographically, Socially, and Culturally Homogeneous Patients

Background

Impact of hemodialysis adequacy on patient survival is extensively studied. The current study compares the survival of chronic hemodialyzed, undocumented, uninsured, Afghan immigrant patients with that of a group of insured Iranian patients matched for underlying disease, age, weight, level of education, marital status, income, and number of comorbid conditions.

Methods

Eighty chronic hemodialysis patients (mean age 42.8 ± 10.5 years) entered this historical cohort study in Mashhad, Iran, between January 2012 and January 2015. Half of the patients were undocumented, uninsured, Afghan immigrants (Group A) matched with forty insured Iranian patients (Group B). To compare the survival rate of the two patient groups, Kaplan–Meir survival analysis test was used.

Results

Group A patients were underdialyzed with a weekly Kt/V which was significantly less in comparison with that of Group B (1.63 ± 0.63 versus 2.54 ± 0.12, p value = 0.01). While Group A's number of hemodialysis sessions per week was fewer than that of Group B (1.45 ± 0.56 versus 2.8 ± 0.41, p value = 0.04), the mean of Kt/V in each hemodialysis session was higher in them, in comparison with Group B (1.43 ± 0.25 versus 1.3 ± 0.07, p value = 0.045). In Group B and Group A patients, one-year survival was 70% versus 50%, two-year survival was 55% versus 30%, and three-year survival was 40% versus 20%, respectively (p values = 0.04, 0.02 and 0.04, respectively). In Cox regression analysis, hemodialysis adequacy and uninsurance were factors impacting patients' survival (OR = 1.193 and 0.333, respectively).

Conclusions

Undocumented, uninsured, inadequately hemodialyzed, Afghan patients had a significantly lower one-, two-, and three-year survival as opposed to their Iranian counterparts, probably due to lack of insurance.

Aspectos clave en el mantenimiento de la diuresis residual en pauta de hemodiálisis incremental. Experiencia de diez años

Introducción: La hemodiálisis incremental o progresiva es una modalidad de inicio de hemodiálisis, basada en la diuresis residual y adaptada a las necesidades del paciente, poco extendida pese a sus potenciales beneficios. Para su correcto seguimiento es necesario establecer unas pautas específicas en cada sesión de hemodiálisis, que deben ser conocidas por el personal que atiende a estos pacientes de forma regular. Objetivo: analizar la evolución de los pacientes que han iniciado tratamiento renal sustitutivo con hemodiálisis incremental. Material y Método: Estudio observacional retrospectivo de pacientes incidentes en tratamiento renal sustitutivo mediante hemodiálisis incremental en nuestro centro en los últimos 10 años. Comparación de resultados basales y a los 12 meses de seguimiento. Resultados: En este periodo de tiempo se han incluido 49 pacientes en técnica de hemodiálisis incremental. Aunque la diuresis residual desciende en el primer año de 2030±600 ml/día a 1300±500 (p<0,05), ésta se mantiene por encima de un litro en la mayoría de los casos. El aclaramiento de urea también desciende de 5,7±1,6 ml/min a 3,4±1,6 ml/min al año (p<0,05). Conclusiones: Iniciar tratamiento renal sustitutivo con hemodiálisis incremental puede mantener más tiempo la diuresis residual, para eso es clave el conocimiento de la técnica y su correcto manejo durante las sesiones de diálisis.

Can incremental haemodialysis reduce early mortality rates in patients starting maintenance haemodialysis?

PURPOSE OF REVIEW

Early mortality rates after the start of maintenance haemodialysis therapy are high. Compared with three-times weekly haemodialysis, incremental haemodialysis is associated with better preservation of residual renal function (RRF) and at least equivalent mid-term to long-term survival. However, there is paucity of data in relation to its use as a means of helping patients through the transitional period, when they first become dialysis dependent.

RECENT FINDINGS

Studies of incremental haemodialysis have overlooked early mortality as an outcome measure. This is primarily due to their retrospective design which makes it difficult to link early deaths to the frequency of haemodialysis. New data confirm previous observations associating incremental haemodialysis with favourable outcomes. They also raise the possibility that in selected groups and for short periods, the pursuit of set clearance targets during the early days of dialysis may not necessarily bring additional short-term gains.

SUMMARY

We argue that, while simpler ways of estimating RRF are being explored, future trials must consider implementing incremental haemodialysis focusing on practical aspects of care in the transitional period; safety monitoring in such regimes should be undertaken using conventional methods. Such an approach is likely to benefit a larger subset of haemodialysis population.

Predicting Residual Function in Hemodialysis and Hemodiafiltration-A Population Kinetic, Decision Analytic Approach

In this study, we introduce a novel framework for the estimation of residual renal function (RRF), based on the population compartmental kinetic behavior of beta 2 microglobulin (B2M) and its dialytic removal. Using this model, we simulated a large cohort of patients with various levels of RRF receiving either conventional high-flux hemodialysis or on-line hemodiafiltration. These simulations were used to estimate a novel population kinetic (PK) equation for RRF (PK-RRF) that was validated in an external public dataset of real patients. We assessed the performance of the resulting equation(s) against their ability to estimate urea clearance using cross-validation. Our equations were derived entirely from computer simulations and advanced statistical modeling and had extremely high discrimination (Area Under the Curve, AUC 0.888–0.909) when applied to a human dataset of measurements of RRF. A clearance-based equation that utilized predialysis and postdialysis B2M measurements, patient weight, treatment duration and ultrafiltration had higher discrimination than an equation previously derived in humans. Furthermore, the derived equations appeared to have higher clinical usefulness as assessed by Decision Curve Analysis, potentially supporting decisions for individualizing dialysis prescriptions in patients with preserved RRF.

Dialysis Reimbursement: What Impact Do Different Models Have on Clinical Choices?

Allowing patients to live for decades without the function of a vital organ is a medical miracle, but one that is not without cost both in terms of morbidity and quality of life and in economic terms. Renal replacement therapy (RRT) consumes between 2% and 5% of the overall health care expenditure in countries where dialysis is available without restrictions. While transplantation is the preferred treatment in patients without contraindications, old age and comorbidity limit its indications, and low organ availability may result in long waiting times. As a consequence, 30–70% of the patients depend on dialysis, which remains the main determinant of the cost of RRT. Costs of dialysis are differently defined, and its reimbursement follows different rules. There are three main ways of establishing dialysis reimbursement. The first involves dividing dialysis into a series of elements and reimbursing each one separately (dialysis itself, medications, drugs, transportation, hospitalisation, etc.). The second, known as the capitation system, consists of merging these elements in a per capita reimbursement, while the third, usually called the bundle system, entails identifying a core of procedures intrinsically linked to treatment (e.g., dialysis sessions, tests, intradialyitc drugs). Each one has advantages and drawbacks, and impacts differently on the organization and delivery of care: payment per session may favour fragmentation and make a global appraisal difficult; a correct capitation system needs a careful correction for comorbidity, and may exacerbate competition between public and private settings, the latter aiming at selecting the least complex cases; a bundle system, in which the main elements linked to the dialysis sessions are considered together, may be a good compromise but risks penalising complex patients, and requires a rapid adaptation to treatment changes. Retarding dialysis is a clinical and economical goal, but the incentives for predialysis care are not established and its development may be unfavourable for the provider. A closer cooperation between policymakers, economists and nephrologists is needed to ensure a high quality of dialysis care.

Residual renal function in incremental dialysis

Incremental haemodialysis has the potential to allow better preservation of renal function, is less invasive to the patient and has lower cost. Despite these advantages, it is not commonly applied. This may be due to uncertainty about how to account for renal function in the prescription of dialysis and measurement of dose. In this issue, Vartia describes the practical basis for including the effect of renal function in the prescription and quantification of dialysis. He uses a well-known and validated urea kinetic model to calculate time average urea concentrations and the equivalent renal clearance (EKR) from dialysis. The effect of renal function is amplified by a weighting factor to account for the relatively greater effect of renal function compared with dialysis with the same urea clearance. In that way, patients on differing dialysis regimens can be dialysed with the same target dose. A further step would be to use a downward adjusting factor for dialysis to convert the urea clearance by dialysis (as EKR) to a glomerular filtration rate (GFR) equivalent. A factor of 0.75 is suggested. In that way, dialysis dose can be reported as GFR equivalent in mL/min/1.73 m2, comparable between different types of dialysis and also to renal function without dialysis.