Short daily hemodialysis and nutritional status

Differences in Malnutrition Inflammation Score of Hemodialysis Patients Associated With Hemodialysis Factors. A Spanish Multicenter Epidemiologic Study

OBJECTIVES

The aims of this study are to analyze the prevalence of malnutrition in hemodialysis (HD) patients in Spain, and to assess the association of malnutrition in these patients with sociodemographic characteristics, comorbidity, and parameters related to HD.

DESIGN AND METHODS

A multicenter, retrospective, cross-sectional study in HD patients from centers all over Spain was conducted. Nutritional status of patients was assessed using Malnutrition Inflammation Score (MIS), and was stratified according to MIS values into 5 categories: ≤2, normal nutrition; >2 to ≤5, mild malnutrition or risk of malnutrition; >5 to ≤7, moderate malnutrition; >7 to ≤10, severe malnutrition, and >10, extreme malnutrition.

RESULTS

A total of 52 Spanish HD Units participated in the study enrolling 2,748 patients. Mean age of patients was 68.20 ± 14.24 years, 1,811 (65.9%) were men. Mean time on HD was 55.63 ± 63.25 months. Using an MIS cut-off point of 2 for malnutrition, 89% of patients were malnourished (MIS > 2). However, with a cut-off point of 5, more commonly described in the literature, the percentage of patients with malnutrition was reduced to 51.7%. Using this cut-off, we observed significant differences between patients with malnutrition and normo-nourished patients in biochemical parameters, age, Charlson Index, HD residual renal function, scheme, and vascular access (permanent catheter vs arteriovenous fistula). A multivariate regression analysis showed that age, sex, HD scheme, vascular access, residual renal function, and comorbidity index were predictive factors for malnutrition. We found that a high percentage of HD patients with malnutrition did not receive oral supplementation.

CONCLUSIONS

The prevalence of malnutrition in HD patients in Spain, assessed using the MIS scale, was high. Higher malnutrition was associated with the use of catheter versus fistula, and standard HD versus online hemodiafiltration, and with the absence of residual renal function, older age, greater comorbidity, and male sex. Malnourished patients had a low rate of oral supplementation.

The effect of high-volume online haemodiafiltration on nutritional status and body composition: the ProtEin Stores prEservaTion (PESET) study

Background

Compared with conventional haemodialysis (HD), online haemodiafiltration (OL-HDF) achieves a more efficient removal of uraemic toxins and reduces inflammation, which could favourably affect nutritional status. We evaluate the effect of OL-HDF on body composition and nutritional status in prevalent high-flux HD (HF-HD) patients.

Methods

In all, 33 adults with chronic kidney disease (CKD) Stage 5 undergoing maintenance HF-HD were assigned to post-dilution OL-HDF (n = 17) or to remain on HF-HD (n = 16, control group) for 12 months. The primary outcome was the change in lean tissue mass (LTM), intracellular water (ICW) and body cell mass (BCM) assessed by multifrequency bioimpedance spectroscopy (BIS) at baseline and 4, 8 and 12 months. The rate of change in these parameters was estimated with linear mixed-effects models.

Results

Compared with OL-HDF, patients assigned to HF-HD experienced a gradual reduction in LTM, ICW and BCM. These differences reached statistical significance at Month 12, with a relative difference of 7.31 kg [95% confidence interval (CI) 2.50-12.11; P = 0.003], 2.32 L (95% CI 0.63-4.01; P = 0.008) and 5.20 kg (95% CI 1.74-8.66; P = 0.004) for LTM, ICW and BCM, respectively. The normalized protein appearance increased in the OL-HDF group compared with the HF-HD group [0.26 g/kg/day (95% CI 0.05-0.47); P = 0.002], with a relative reduction in high-sensitive C-reactive protein [-13.31 mg/dL (95% CI -24.63 to -1.98); P = 0.02] at Month 12.

Conclusions

OL-HDF for 1 year compared with HF-HD preserved muscle mass, increased protein intake and reduced the inflammatory state related to uraemia and dialysis, supporting the hypothesis that high convection volume can benefit nutritional status and prevent protein-energy wasting in HD patients.

Mortality and Hospitalizations in Intensive Dialysis: A Systematic Review and Meta-Analysis

Background:

Survival and hospitalization are critically important outcomes considered when choosing between intensive hemodialysis (HD), conventional HD, and peritoneal dialysis (PD). However, the comparative effectiveness of these modalities is unclear.

Objective:

We had the following aims: (1) to compare the association of mortality and hospitalization in patients undergoing intensive HD, compared with conventional HD or PD and (2) to appraise the methodological quality of the supporting evidence.

Data Sources:

MEDLINE, Embase, ISI Web of Science, CENTRAL, and nephrology conference abstracts.

Study Eligibility, Participants, and Interventions:

We included cohort studies with comparator arm, and randomized controlled trials (RCTs) with >50% of adult patients (≥18 years) comparing any form of intensive HD (>4 sessions/wk or >5.5 h/session) with any form of chronic dialysis (PD, HD ≤4 sessions/wk or ≤5.5 h/session), that reported at least 1 predefined outcome (mortality or hospitalization).

Methods:

We used the GRADE approach to systematic reviews and quality appraisal. Two reviewers screened citations and full-text articles, and extracted study-level data independently, with discrepancies resolved by consensus. We pooled effect estimates of randomized and observational studies separately using generic inverse variance with random effects models, and used fixed-effects models when only 2 studies were available for pooling. Predefined subgroups for the intensive HD cohorts were classified by nocturnal versus short daily HD and home versus in-center HD.

Results:

Twenty-three studies with a total of 70 506 patients were included. Of the observational studies, compared with PD, intensive HD had a significantly lower mortality risk (hazard ratio [HR]: 0.67; 95% confidence interval [CI]: 0.53-0.84; I² = 91%). Compared with conventional HD, home nocturnal (HR: 0.46; 95% CI: 0.38-0.55; I² = 0%), in-center nocturnal (HR: 0.73; 95% CI: 0.60-0.90; I² = 57%) and home short daily (HR: 0.54; 95% CI: 0.31-0.95; I² = 82%) intensive regimens had lower mortality. Of the 2 RCTs assessing mortality, in-center short daily HD had lower mortality (HR: 0.54; 95% CI: 0.31-0.93), while home nocturnal HD had higher mortality (HR: 3.88; 95% CI: 1.27-11.79) in long-term observational follow-up. Hospitalization days per patient-year (mean difference: –1.98; 95% CI: –2.37 to −1.59; I² = 6%) were lower in nocturnal compared with conventional HD. Quality of evidence was similarly low or very low in RCTs (due to imprecision) and observational studies (due to residual confounding and selection bias).

Limitations:

The overall quality of evidence was low or very low for critical outcomes. Outcomes such as quality of life, transplantation, and vascular access outcomes were not included in our review.

Conclusions:

Intensive HD regimens may be associated with reduced mortality and hospitalization compared with conventional HD or PD. As the quality of supporting evidence is low, patients who place a high value on survival must be adequately advised and counseled of risks and benefits when choosing intensive dialysis. Practice guidelines that promote shared decision-making are likely to be helpful.

[Low flux dialysate daily home hemodialysis: A result for the 62 first French and Belgian patients]

Since 2011, a new device is available for low flux dialysate quotidian home hemodialysis in France and Belgium. This study aims to evaluate the characteristics and dialysis prescriptions for Nx Stage System One™ users. We retrospectively included patients trained between 2011 and 2013 in France and Belgium. We collected data concerning their clinical features, their dialysis prescriptions, their laboratory parameters until 6 months of dialysis and, reason for dropping in case of cessation. Sixty-two patients from 31 centers, aged 48±18 years old, with a sex ratio 46/16 (M/F) are included with a median Charlson comorbidity index of 1 [0-3]. Of these patients, 71% are anuric and have been on dialysis for a mean time of 136.6±125 months. Previously, most of them had been taken care of in satellite units of dialysis (45%) and 14% are incident patients. In total, A total of 60% have an arterio-veinous fistula (AVF), with 18 patients using the Buttonhole system and 2 patients have a tunneled catheter. Median time for training was 26.5 days (17-45). Among the patients, 69% are dialyzed 6 days a week, during a mean time of 142.5±20 minutes with a volume of 20.9±3 liters of dialysate and without anticoagulant (63%). Predialytic levels of hemoglobin, creatinin, urea, phosphorus and β2microglobulin remain stable. On the contrary, there is a significant improvement of albumin and bicarbonate levels. Technique survival was 75% at 1 year, and major reason for cessation was kidney transplant. It seems that this device fits for young patients, with few comorbidities and a long past in renal chronic failure. These results suggest that dialysis adequacy is acceptable despite low dialysate volumes but need confirmation with a longer follow up and a larger cohort.

Malnutrition in Dialysis Patients--The Need for Intervention Despite Uncertain Benefits

We are in the midst of an epidemic of overnutrition which has resulted in a widespread increase in obesity rates in modern societies. Yet for patients suffering from serious chronic illnesses such as end stage renal disease (ESRD), malnutrition (encompassing both inadequate quantity and quality of nutrient intake) represents a far more significant danger. Protein-energy wasting has been identified as one of the strongest risk factor for adverse outcomes in ESRD patients, and modeling studies have suggested that improving nutrition could result in substantial lowering of mortality rates and other benefits. To date there is ample evidence that various interventions can have a positive impact on the nutritional status of ESRD patients, yet we still lack randomized controlled clinical trials showing that the same interventions could indeed lead to better survival or other clinical benefits. This knowledge gap, which is all too common for clinical problems encountered in nephrology, should not act as a deterrent, but it should rather incentivize us to continue exploring novel interventions aimed at improving malnutrition in ESRD.

Infrequent dialysis: a new paradigm for hemodialysis initiation

Nearly a half-century ago, the thrice-weekly hemodialysis schedule was empirically established as a means to provide an adequate dialysis dose while also treating the greatest number of end-stage renal disease (ESRD) patients using limited resources. Landmark trials of hemodialysis adequacy have historically been anchored to thrice-weekly regimens, but a recent randomized controlled trial demonstrated that frequent hemodialysis (six times per week) confers cardiovascular and survival benefits. Based on these collective data and experience, clinical practice guidelines advise against a less than thrice-weekly treatment schedule in patients without residual renal function, yet provide limited guidance on the optimal treatment frequency when substantial native kidney function is present. Thus, during the transition from Stage 5 chronic kidney disease to ESRD, the current paradigm is to initiate hemodialysis on a "full-dose" thrice-weekly regimen even among patients with substantial residual renal function. However, emerging data suggest that frequent hemodialysis accelerates residual renal function decline, and infrequent regimens may provide better preservation of native kidney function. Given the high mortality rates during the first 6 months of hemodialysis and the survival benefits of preserved native kidney function, initiation with twice-weekly treatment schedules ("infrequent hemodialysis") with an incremental increase in frequency over time may provide an opportunity to optimize patient survival. This review outlines the clinical benefits of post-hemodialysis residual renal function, studies of twice-weekly treatment regimens, and the potential risks and benefits of infrequent hemodialysis.

The impact of short daily hemodialysis on anemia and the quality of life in Chinese patients

Anemia is a frequent complication in hemodialysis patients. Compared to conventional hemodialysis (CHD), short daily hemodialysis (sDHD) has been reported to be effective in many countries except China. The aim of the present study was to determine whether sDHD could improve anemia and quality of life (QOL) for Chinese outpatients with end-stage renal disease. Twenty-seven patients (16 males/11 females) were converted from CHD to sDHD. All laboratory values were measured before conversion (baseline), at 3 months after conversion (sDHD1), and at 6 months after conversion (sDHD2). The patient's QOL was evaluated at baseline and 6 months after conversion using the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36). Hemoglobin concentration increased significantly from 107.4±7.9 g/L at baseline to 114.4±6.8 g/L (P<0.05) at sDHD1, and 118.3±8.4 g/L (P<0.001) at sDHD2 (Student paired t-test). However, the dose requirement for erythropoietin decreased from 6847.8±1057.3 U/week at baseline to 5869.6±1094.6 U/week (P<0.05) at sDHD2. Weekly stdKt/V increased significantly from 2.05±0.13 at baseline to 2.73±0.20 (P<0.001) at sDHD1, and 2.84±0.26 (P<0.001) at sDHD2. C-reactive protein decreased from baseline to sDHD1 and sDHD2, but without statistically significant differences. Physical and mental health survey scores increased in the 6 months following conversion to sDHD. sDHD may increase hemoglobin levels, decrease exogenous erythropoietin dose requirements, and improve QOL in Chinese hemodialysis patients compared to CHD. A possible mechanism for improvement of clinical outcomes may be optimized management of uremia associated with the higher efficiency of sDHD.

The effect of frequent hemodialysis on nutrition and body composition: frequent Hemodialysis Network Trial

We investigated the effects of frequency of hemodialysis on nutritional status by analyzing the data in the Frequent Hemodialysis Network Trial. We compared changes in albumin, body weight and composition among 245 patients randomized to 6- or 3-times per week in-center hemodialysis (Daily Trial) and 87 patients randomized to 6-times per week nocturnal or 3-times per week conventional hemodialysis, performed largely at home (Nocturnal Trial). In the Daily Trial, there were no significant differences between groups in changes in serum albumin or the equilibrated protein catabolic rate by 12 months. There was a significant relative decrease in pre-dialysis body weight of 1.5 ± 0.2 kg in the 6 times per week group at one month, but this significantly rebounded by 1.3 ± 0.5 kg over the remaining 11 months. Extracellular water decreased in the 6 times per week compared to the 3 per week hemodialysis group. There were no significant between-group differences in phase angle, intracellular water or body cell mass. In the Nocturnal Trial, there were no significant between-group differences in any study parameter. Any gain in “dry” body weight corresponded to increased adiposity rather than muscle mass but was not statistically significant. Thus, frequent in-center hemodialysis reduced extracellular water but did not increase serum albumin or body cell mass while frequent nocturnal hemodialysis yielded no net effect on parameters of nutritional status or body composition.

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.

Simultaneous Blood Temperature Control and Blood Volume Control Reduces Intradialytic Symptoms

Purpose

Intra-dialytic morbid events (IME; e.g. hypotension, cramps, headaches) are frequent complications during hemodialysis (HD), known to be associated with ultrafiltration-induced hypovolemia and body temperature changes. Feedback control of blood volume adjusts the ultrafiltration rate in order to keep the blood volume above the patient's individual limit; feedback control of blood temperature maintains the mean arterial blood temperature at the individual pre-dialytic level. Each of these methods reduces the frequency of IME.

Methods

In a randomized clinical trial the simultaneous application of both feedback controls was investigated for the first time. In 15 weeks, each patient went through 3 study phases: an observational screening phase, a standard phase (STD), and a blood temperature- and blood volume-control phase (CTL). Patients with at least 5 sessions with IME out of 15 sessions in the screening phase were eligible for the study and randomized either into sequence STD-CTL or CTL-STD.

Results

26 patients completed the study according to protocol, and 778 HD treatments were analyzed. The general treatment parameters were similar in both study phases: treatment duration (STD: 244 min, CTL: 243 min, NS), pre-dialytic weight (STD: 72.3 kg, CTL: 72.2 kg, NS), and weight loss due to ultrafiltration (STD: 3.26 kg, CTL: 3.15 kg, NS). The proportion of HD treatments with IME was 32.8% during STD and 18.0% during CTL (p=0.024).

Conclusions

The frequency of HD sessions with IME was significantly reduced by 45% compared to standard HD in this randomized clinical trial by use of individualized HD treatments with simultaneous feedback control of blood volume and blood temperature.

Genomic damage in endstage renal disease-contribution of uremic toxins

Patients with end-stage renal disease (ESRD), whether on conservative, peritoneal or hemodialysis therapy, have elevated genomic damage in peripheral blood lymphocytes and an increased cancer incidence, especially of the kidney. The damage is possibly due to accumulation of uremic toxins like advanced glycation endproducts or homocysteine. However, other endogenous substances with genotoxic properties, which are increased in ESRD, could be involved, such as the blood pressure regulating hormones angiotensin II and aldosterone or the inflammatory cytokine TNF-α. This review provides an overview of genomic damage observed in ESRD patients, focuses on possible underlying causes and shows modulations of the damage by modern dialysis strategies and vitamin supplementation.

[Can the hemodialysis strategy influence the nutritional status of hemodialysis patients?]

Malnutrition is frequent in hemodialysis (HD) patients. The HEMO study has shown a progressive decline of nutritional markers, such as body weight, albuminemia and protein intake, in prevalent hemodialysis patients during a 3-year follow-up. In incident dialysis patients, nutritional status usually improves during the first year of HD treatment. Opposite to the HEMO findings, we have shown that nutritional stability was achieved during a 5 year follow-up with sequential long hour dialysis (3 x 6-8 hours/week). Energy and protein intakes are related to the dialysis dose. Moreover, several studies show the nutritional consequences of changing the dialysis prescriptions. The switch from conventional HD to short daily dialysis improves significantly protein and energy intake and albuminemia. Also, increasing treatment time increases significantly the body weight after several months. One of the hypothesis for this effect is that uremia-related middle molecules compromise the patient appetite. Increasing dialysis time or frequency may decrease the level or the time of exposition to these molecules. However, the beneficial effect of hemodiafiltration on HD patients' nutritional status is not spectacular. Another hypothesis is the role of extra-cellular fluid excess and its relationship with inflammation that is deleterious for nutrition. In conclusion, dialysis adequacy is a mandatory prerequisite when facing a malnourished HD patient. Increasing time or frequency must be part of the therapeutic thought in such situation.

Review article: Biomarkers of clinical outcomes in advanced chronic kidney disease

Chronic kidney disease (CKD) is a complex condition, where the decrease in kidney function is accompanied by numerous metabolic changes affecting virtually all the organ systems of the human body. Many of the biomarkers characteristic of the individually affected organ systems have been associated with adverse outcomes including higher mortality in advanced CKD, whereas in persons without CKD these biomarkers may have no bearing on survival. It is believed that the high mortality seen in CKD is a result of several abnormalities conspiring to induce or aggravate a heightened degree of cardiovascular morbidity and predisposition to wasting syndrome. Not all the biomarkers may, however, be causally responsible for the adverse outcomes associated with them. We review various biomarkers of protein-energy wasting, inflammation, oxidative stress, potassium disarrays, acid-base disorders, bone and mineral disorders, glycemic status, and anemia. Although all of these biomarkers have shown associations with worsened outcomes in CKD, markers of protein-energy wasting, especially serum albumin, remain the strongest predictor of survival in CKD patients, especially those undergoing maintenance dialysis treatment. We also review the putative pathophysiologic mechanisms behind these associations, and present potential therapeutic interventions that could result in remedies to improve poor clinical outcomes in CKD, pending the results of current and future controlled trials.

Effect of treatment frequency on haemodialysis dose: comparison of EKR and stdKt/V

BACKGROUND

Haemodialysis outcome cannot be improved by increasing the dialysis session dose above the current standard in conventional schedules. Promising results have been reported from daily dialysis, but the optimal dose has not been established.

METHODS

Weekly eKt/V, equivalent renal clearance (EKR) and stdKt/V were compared retrospectively in 588 complete urea kinetic modelling sessions of 35 haemodialysis patients. Equivalent values of EKR and stdKt/V corresponding to the standard and high doses of the HEMO study were defined by computer simulation. The effect of frequency on the dose measures was demonstrated by simulating different schedules.

RESULTS

EKR and stdKt/V take into consideration both frequency and RRF, but appreciate them differently. The values of EKRc (EKR in millilitres per minute, normalized to distribution volume 40 l), stdEKR (EKR in litres per week divided by urea distribution volume in litres) and stdKt/V corresponding to eKt/V 1.20-close to the standard dose in the HEMO study-were 13.2 ml/min/40 l, 3.34/wk and 2.23/wk, respectively. stdKt/V appreciates frequency more than EKR. A spreadsheet was created to compute the dialysis session time to achieve the EKR or stdKt/V target when the basic urea kinetic variables are known.

CONCLUSIONS

Haemodialysis efficiency can be increased by increasing frequency. EKR and stdKt/V are more appropriate than weekly eKt/V as measures of dialysis dose in different schedules. With increasing frequency, stdKt/V as the dosing target results in shorter treatment times and higher concentrations than EKR.

Why is protein-energy wasting associated with mortality in chronic kidney disease?

Observational studies in chronic kidney disease (CKD) populations consistently have shown the strong mortality-predictability of such markers of protein-energy wasting (PEW) as hypoalbuminemia, low serum cholesterol levels, low body mass index, and reduced dietary protein intake. Even though the PEW-mortality association data traditionally are reported mostly in maintenance dialysis patients, emerging studies extend the existence of these associations to predialysis stages of CKD. Paradoxic risk factor patterns (reverse epidemiology) for both obesity and cholesterol recently have been reported in predialysis CKD, underscoring the overwhelming impact of PEW, a short-term killer, on reversing the long-term effect of conventional cardiovascular risk factors. Multiple pathophysiologic mechanisms have been suggested to explain the link between PEW and mortality in CKD, including derangements in muscle, adipose tissue, and the gastrointestinal, hematopoietic, and immune systems; complications related to deficiencies of multiple micronutrients; and the maladaptive activation of the inflammatory cascade. In addition to well-described pathophysiologic mechanisms involved in the higher mortality seen with PEW, we also discuss the potential role of novel factors such as circulating actin, gelsolin, and proinflammatory high-density lipoprotein. Whether PEW is causally related to adverse outcomes in CKD needs to be verified in randomized controlled trials of nutritional interventions. The initiation of major clinical trials targeting nutritional interventions with the goal of improving survival in CKD offer the promise of extending the survival of this vulnerable patient population.

Should the medicare ESRD program pay for daily dialysis? An ethical analysis

End-stage renal disease (ESRD) is a growing problem in the United States and has now reached epidemic proportions. The mortality rate and other complications related to conventional dialysis remain unacceptably high necessitating improvements in dialytic therapies. One strategy has been to increase dialysis frequency through daily dialysis since the Hemodialysis study showed that clinical outcomes are not improved by simply increasing delivered dialysis dose per session. Most studies of daily dialysis are observational and limited by small sample size, variable dialysis techniques, high patient dropout, and lack of adequate control group. These studies have shown consistent improvements in blood pressure and solute clearance, but improvements in patient survival, anemia, and health-related quality of life are less clear. The costs of providing daily dialysis on a large scale are likely to be substantial. However, if there are significant improvements in the outcome measures outlined earlier as well as decreased hospitalization rates, daily dialysis may prove cost-effective or budget neutral from a global standpoint. A scientific basis is needed to justify a change in the Medicare ESRD Program to fund daily dialysis. Decisions regarding the allocation of limited medical resources such as the Medicare budget should consider ethically appropriate criteria including likelihood of benefit, urgency of need, change in quality of life, duration of benefit, patient selection, equitable distribution, and the amount of resources required. In examining the evidence base on daily dialysis according to these ethical criteria, we find that there are not yet sufficient grounds to recommend funding of daily dialysis by the Medicare ESRD Program. Randomized controlled trials comparing conventional hemodialysis to short daily and long nocturnal hemodialysis are much needed.

An update on nutrition in chronic kidney disease

The prevalence of malnutrition in the course of chronic kidney disease has not changed recently and is still between 30 and 50%. About 10% of patients on maintenance dialysis show signs of severe malnutrition. Recent progress has been made on protein metabolism, the validation of new diagnostic tools, and the use of anabolic compounds. Large clinical trials have characterized the use of medications for renutrition, and international guidelines are currently updated. Neverthless, physicians will be mostly efficient at the stage of malnutrition prevention, by implementing an early, interactive dietary and nutritional care programs in close collaboration with specialized dietitians.

Stability of nutritional parameters during a 5-year follow-up in patients treated with sequential long-hour hemodialysis

Progressive nutritional impairment has been recently reported during conventional hemodialysis (HD) treatment. We studied the nutritional parameters during a 5-year follow-up in HD patients. Thirty-three patients (15F/18M; 65 years old at the study start) filled out a 3-day food questionnaire once a year between 1995 and 1999 (study group). Twenty patients, who did not fill out the food records during this period served as a control group (control group). The food record was run by the renal dietician using a dedicated software, providing daily energy and protein intakes (DEI and DPI). Serum albumin, normalized protein equivalent of nitrogen appearance (nPNA), and postdialysis body weight (BW) at the time of food record were collected in the study group and from the patient chart in the control group. The energy intake in the study group and the protein intake in both groups were close to the recommended intakes in ESRD patients. Protein intake assessed from food questionnaire or from urea kinetics were not statistically different. Using ANOVA for repeated measures, no difference along the 5 years was found for daily energy intake, daily protein intake, nPNA, and BW in the study group. The BW and nPNA remained stable in the control group. Hence, this study does not confirm the progressive nutritional impairment reported in the HEMO study, whereas the patients' age and vintage are largely higher in the present study. The role of a large dialysis dose in maintaining nutritional status in HD patients is discussed.

A crossover study of short daily haemodialysis

BACKGROUND

The benefits of daily haemodialysis (DHD) compared to conventional three times per week haemodialysis (CHD) have been described in a number of observational studies. Most of these previous studies however have not been performed with rigorous controls.

METHODS

We performed a crossover study following an A-B-A design: phase A was 4 weeks of thrice weekly dialysis, 3-4 h per treatment (CHD); phase B was 8 weeks of six times/week dialysis, each session being one-half of the usual time (DHD) and phase A with 4 weeks of thrice weekly dialysis (CHD) was repeated. Patients characteristics: n=12, six males; age 52+/-18 years, six diabetics.

RESULTS

Weekly single-pool Kt/V, equilibrated Kt/V and standard Kt/V of urea, and beta-2-microglobulin clearance values were greater during DHD. Eight of 12 patients who completed the study reported symptomatic benefits from DHD that partially or completely disappeared during the second period of CHD. Quality of life of patients improved during DHD. Three patients had problems with arteriovenous access during DHD. Average blood pressure was lower during DHD (systolic 139.5+/-22.7 mmHg) compared to the initial (147.7+/-21.4 mmHg, P<0.001) and last (146.4+/-20.0 mmHg, P<0.005) CHD periods. No significant changes in predialysis haemoglobin and the serum concentration of albumin, phosphate, beta-2-microglobulin or B-type natriuretic peptides (BNP) were observed, although BNP trended downward during DHD and returned to baseline level during the second period of CHD. The dose of erythropoietin did not change significantly. Patient compliance with the dialysis schedule was lower during DHD. Dialysis staff perceived an increased workload but felt that the patients benefited medically from DHD.

CONCLUSIONS

The results of this cross-over study suggest symptomatic benefits and decrease in blood pressure, but there are potential problems with compliance and vascular access during DHD.

Malnutrition in Hemodialysis Patients: What Therapy?

Malnutrition is common in hemodialysis patients and is a powerful predictor of morbidity and mortality. Although much progress has been made in recent years in identifying the causes and pathogenesis of malnutrition in hemodialysis patients, as well as recognizing the link between malnutrition and morbidity and mortality, no consensus has been reached concerning its management. Along with such conventional interventions as nutritional counseling, oral nutritional supplements, and intradialytic parenteral nutrition, novel preventive and therapeutic strategies have been tested, such as appetite stimulants, growth hormone, androgenic anabolic steroids, and anti-inflammatory drugs, with contradictory and nonconclusive results. Malnutrition still remains a great challenge for nephrologists in the third millennium.

Patient preferences for in-center intense hemodialysis

There is a lack of data on patient preferences for intense hemodialysis (IHD). In this study, we conducted a cross-sectional survey to identify patient preferences and patient-centered barriers for IHD. A questionnaire on preferences and anticipated barriers, anticipated benefits, and quality of life for three in-center IHD schedules (daytime 2 hr six times/week [DHD], nocturnal 8 hr three times/week [ND3], and nocturnal 8 hr six times/week [ND6]) was administered to 100 chronic hemodialysis patients. A majority of patients (68%) were willing to undergo DHD for symptomatic benefits or increase in survival. An increase in energy level (94%) and improvement in sleep (57%) were the most common potential benefits that would justify DHD, but only 19% would undergo DHD for an increase in survival of < or =3 years. Only 20% and 7% would consider ND3 and ND6, respectively. The most common reported barriers were inadequate time for self (50%) and family (53%), followed by transportation difficulties (53%). Most patients would undergo DHD for symptomatic or survival benefits, but not ND3 or ND6. Disruption of personal time, however, is an important consideration. Success of DHD program would depend on arrangements for transportation to dialysis unit.

Switch from Bicarbonate Hemodialysis to Hemodiafiltration with Online Regeneration of the Ultrafiltrate (HFR): Effects on Nutritional Status, Microinflammation, and beta2-Microglobulin

BACKGROUND

Hemodiafiltration (HFR) with on-line regeneration of the ultrafiltrate, a technique of hemodiafiltration in which the ultrafiltrate passes through a cartridge containing uncoated charcoal, has been shown to be safe, simple, and well tolerated and has been claimed to improve nutritional status or to prevent its deterioration while decreasing the inflammatory response via a reduced production of proinflammatory cytokines. The purpose of the present prospective study was to ascertain whether HRF improves the nutritional status, reduces microinflammation, and decreases serum beta2-microglobulin levels in patients with end-stage renal disease (ESRD).

METHODS

Eight patients, four males and four females, with a mean age of 49.4 +/- 16.8 years, stable on hemodialysis over a period of 8.7 +/- 6.1 years and on standard 4-4.5 h three-times-a-week bicarbonate hemodialysis, were switched to three-times-a-week, 4-h HFR. At baseline and every two months for 12 months at mid-week, serum levels of urea, creatinine, albumin, total cholesterol, C-reactive protein, fibrinogen, complement, ferritin, beta2-microglobulin, intact parathyroid hormone (PTH), hemoglobin concentrations, and hematocrit and the EPO weekly dose were determined. At baseline and at the end of the study, the Malnutrition Inflammatory Score (MIS) was calculated.

RESULTS

Nutritional and inflammatory parameters remained constant during the 12-month period of the study. After 12 months of HFR, the MIS trended to be lower, but the difference was not statistically significant. Serum beta2-microglobulin and PTH levels remained constant during all time intervals. Neither hematocrit nor hemoglobin changed over the course of the study as well as the weekly EPO dose.

CONCLUSION

The change from bicarbonate hemodialysis to HFR was safe and well tolerated but was not associated with an improvement of nutritional and inflammatory parameters or a reduction of serum beta2-microglobulin levels.

Hypertension control with daily dialysis

Hypertension is present in 60-90% of patients on maintenance hemodialysis (HD) and it is an important cause of cardiovascular (CV) mortality and morbidity. Frequent and prolonged HD has been uniformly shown to control hypertension in end-stage renal disease (ESRD) patients more effectively than conventional HD. The etiology of hypertension is predominantly volume dependent, but in a subset of patients increased renin, sympathetic overactivity, and endothelial dysfunction may play a role. Intradialytic hypotension precludes attainment of dry weight and hence optimal control of hypertension in conventional HD is challenging. Frequent and prolonged dialysis with gentle and persistent ultrafiltration allows time for refilling of the intravascular compartment and permits normalization of extracellular volume. It is also possible that intensive dialysis enables removal of pressor molecules and improves endothelial function. Improved blood pressure control translates into regression of left ventricular hypertrophy in patients on daily HD. Thus prolonged and frequent dialysis permits better control of hypertension via volume and volume-independent mechanisms and also improves cardiac geometry.

Quantifying daily hemodialysis

Nearly all published reports and clinical studies of hemodialysis solute kinetics are confined to thrice-weekly dialysis schedules. Over the past 40 years, clinical experience with dialysis treatments given three times per week has expanded enormously, but it was not until the Hemodialysis (HEMO) study results were revealed that nephrologists became fully aware of the limits of usefulness of infrequent dialysis. In light of continued reports of improved quality of life and survival with daily dialysis, it appears that the limits of thrice-weekly dialysis may be extended when treatments are given more often. Analysis of solute kinetics during and between dialyses supports the notion that a more frequent schedule delivers more efficient dialysis and that methods can be developed to allow a comparison of risks among patients treated 3-7 days per week. One such method, based on the concept of solute seclusion, suggests that at the currently established minimum standard dose, approximately 50% of the improvement in solute control afforded by seven treatments per week is achieved by increasing the frequency to four treatments per week. The same model shows that seven treatments per week afford an improvement in solute control that is approximately 80% as effective as continuous dialysis. These conclusions are similar to those derived from a completely different model based on peak concentration toxicity. Neither of these models has been clinically tested, so caution must be advised when treating individual patients.

Rationale and experience with short daily hemofiltration

Patients with end-stage renal disease (ESRD) have morbidity and mortality rates that are much higher than those found in the general population. The nonphysiologic nature of thrice-weekly hemodialysis may be partially responsible for the poor outcomes in this patient population. In response to the problems encountered with conventional hemodialysis schedules, a number of investigators have explored potential solutions to the problem. One such solution is to increase the time and/or frequency of hemodialysis. With this approach, ESRD patients have been observed to have better anemia management and blood pressure control, as well as improvements in quality of life. Hemodialysis is based on diffusion of solutes across a semipermeable membrane such that only small molecules are readily removed. Therefore a second solution has been to utilize hemofiltration instead of hemodialysis. Hemofiltration utilizes convective clearance of molecules, resulting in an improvement in the removal of larger solutes, much like the glomerular basement membrane of the kidney. Despite the accumulated evidence that thrice-weekly hemofiltration adds to the benefits seen with increasing hemodialysis time and/or frequency, the use of hemofiltration has been limited by the available technology, cost, and low access blood flows. However, current technological advances in equipment and access creation are addressing these problems. With these advances, a number of investigators have also explored the potential benefits of daily hemofiltration as a treatment option for ESRD. The preliminary results suggest that improvements in blood pressure, beta2-microglobulin (beta2M) levels, and quality of life are possible.

Management of anemia with quotidian hemodialysis

BACKGROUND

Most patients with end-stage renal disease have chronic anemia caused by inadequate erythropoietin (EPO) synthesis and require therapy with exogenous EPO to maintain recommended hematocrit and hemoglobin levels.

METHODS

The London Daily/Nocturnal Hemodialysis Study compared anemia control among patients on either short daily, long nocturnal, or conventional thrice-weekly hemodialysis (HD) therapy. Patients were administered iron, either orally (900 mg/d) or intravenously (50 to 125 mg every 1 to 4 weeks), to maintain serum ferritin levels at greater than 45 ng/mL (100 microg/L) or transferrin saturations greater than 20%. EPO was administered by subcutaneous injection at frequencies ranging from twice weekly to once every second week to maintain hemoglobin levels within the target range of 11 to 12 g/dL (110 to 120 g/L).

RESULTS

Both the daily HD and nocturnal HD study groups showed increased hemoglobin levels at later times compared with baseline levels, although only nocturnal HD patients had a statistically significant increase in hemoglobin levels at 18 months (11.94 g/dL [119.4 g/L] versus 10.95 g/dL [109.5 g/L] at baseline; P = 0.047). Both the daily HD and control groups showed a trend for decreased EPO dose requirements at later times compared with baseline, although these decreases were not statistically significant. The nocturnal HD group showed increased EPO dose requirements, although not statistically significant.

CONCLUSION

Quotidian HD is associated with an increased quantity of blood loss that can account for some of the increased requirements in EPO dose. Additional studies with larger numbers of patients are needed to fully elucidate the effects of quotidian HD on anemia.

Change from three times a week on-line hemodiafiltration to short daily on-line hemodiafiltration

BACKGROUND

Daily dialysis has shown excellent clinical results because a higher frequency of dialysis is more physiologic. On-line hemodiafiltration (OL-HDF) is a HDF technique that combines diffusion with high convection in which the dialysis fluid itself is used as a reinfusion solution. The aim of this study was to demonstrate the beneficial effect of the more effective dialysis schedule (daily dialysis) with the dialysis modality that offers the highest uremic toxin removal (on-line HDF).

METHODS

Eight patients, six males and two females, on standard 4 to 5 hours three times a week OL-HDF (S-OL-HDF) were switched to daily OL-HDF (D-OL-HDF) 2 to 21/2 hours six times per week. Dialysis parameters were identical during both periods and only frequency and dialysis time of each session were changed. Tolerance, uremic toxin removal, urea kinetics, biochemical and anemia profiles, blood pressure, and left ventricular hypertrophy were evaluated.

RESULTS

D-OL-HDF was well accepted and tolerated. The disappearance of postdialysis fatigue was rapidly reported by patients. Patients mantained the same [time average concentration (TAC) and weekly single-pool Kt/V (spKt/V)] throughout the study. However, equivalent renal urea clearance (EKR), standard Kt/V and weekly urea reduction ratio (URR) were increased during D-OL-HDF. Weekly urea, creatinine, osteocalcin, beta2-microglobulin, myoglobin, and prolactin reduction ratios were improved with D-OL-HDF. There was a significant decrease in predialysis plasma levels of urea, creatinine, acid uric, beta2-microglobulin and homocysteine over 6 months. Phosphate binders were reduced and antihypertensive drugs were stopped. A 30% regression of left ventricular mass was observed.

CONCLUSION

The change from S-OL-HDF to D-OL-HDF was well tolerated. Disappearance of postdialysis fatigue, better dialysis adequacy, a higher removal of middle and large molecules, a reduction of phosphate binders, improvement of status nutritional, and an important reduction of cardiovascular risk factors were observed.

Calcium and phosphate balance with quotidian hemodialysis

BACKGROUND

Conventional hemodialysis (HD) is associated with profound disturbances in calcium and phosphate metabolism and abnormal parathyroid hormone (PTH) levels. Effects of more frequent HD on calcium and phosphate balance have not been fully elucidated.

METHODS

The London Daily/Nocturnal Hemodialysis Study examined effects of quotidian HD, either daily HD (n = 11) or nocturnal HD (n = 12), on calcium and phosphate metabolism, bone alkaline phosphatase levels, and intact PTH (iPTH) levels.

RESULTS

Daily HD patients showed a slight decrease in predialysis serum phosphate levels, no changes in phosphate-binder requirements or serum calcium levels, and slight increases in serum bone alkaline phosphatase and iPTH levels. Nocturnal HD patients showed a trend for decreased predialysis phosphate levels, with significantly lower values than daily HD and matched control patients on conventional HD therapy at several times. Phosphate-binder use by nocturnal HD patients was significantly reduced. Both quotidian HD groups showed decreases in calcium x phosphate product, with significantly lower values for nocturnal HD patients (38.11 mg(2)/dL(2)) compared with daily HD and control patients (53.99 and 52.51 mg(2)/dL(2), respectively) at 18 months. Bone alkaline phosphatase levels increased slightly and attained statistical significance compared with baseline values for both quotidian HD groups. A trend for increases in serum iPTH levels, coupled with increasing levels of bone alkaline phosphatase in nocturnal HD patients, led to the decision to increase the dialysate calcium concentration from 5.0 to 7.0 mg/dL. This 1-time adjustment resulted in a reversal of the trend and a return to baseline values.

CONCLUSION

This study shows the superior control of serum phosphate levels in nocturnal HD patients compared with daily HD or conventional HD patients and the benefits of dialysate with a greater calcium concentration in slow nocturnal HD.

The impact of quotidian hemodialysis on nutrition

BACKGROUND

Malnutrition is a common problem in hemodialysis (HD) patients and one of the most important factors influencing morbidity and mortality. More frequent HD has been shown to improve nutritional status in HD patients.

METHODS

The London Daily/Nocturnal Hemodialysis Study compared the nutritional status of patients receiving quotidian HD, either short daily HD (n = 11) or long nocturnal HD (n = 12), with that of 22 matched control patients receiving conventional thrice-weekly HD. A number of biochemical parameters indicative of nutritional status were measured, including protein equivalent of total nitrogen appearance (nPNA), serum albumin, serum prealbumin, dietary calcium, serum lipids, and water-soluble vitamin levels.

RESULTS

nPNA tended to increase throughout the study for both quotidian HD groups and remained unchanged in the control group, which had the lowest values (1 to 1.1 g/kg/d). Daily HD patients showed a significant increase in mean serum albumin levels at 3, 12, and 18 months. The nocturnal HD group showed a significant decrease in albumin levels at month 9, and control patients maintained relatively stable albumin levels throughout the study. Serum prealbumin levels averaged 0.04 g/dL for daily HD patients, whereas serum prealbumin levels decreased in nocturnal HD patients during the study period. Half the nocturnal HD patients had vitamin C levels lower than the reference range. Body composition data showed increased arm muscle area and maintenance of 100% to 110% of relative body weight (RBW) after several months of daily HD, whereas patients on nocturnal HD therapy showed a significant decline in RBW. There were no significant differences in lean body mass, percentage of body fat, or body mass index among the 3 study groups.

CONCLUSION

Increased nPNA, serum albumin levels, and arm muscle area suggest that daily HD patients experienced improved nutritional status.

Nutritional problems associated with end-stage renal disease in the developing world

Protein-energy malnutrition is a major problem in dialysis patients. There is increased morbidity and mortality in dialysis patients with malnutrition. There are very few published studies on nutritional parameters and adequacy of dialysis from the developing world and especially from Africa. There was a significant improvement in neuromuscular function and nutrition in 22 hemodialysis patients in Egypt with optimization of dialysis dose and nutritional status. In a study of 82 continuous ambulatory peritoneal dialysis (CAPD) patients in Durban, South Africa, there was a reduction in the number of hospital admissions in adequately dialyzed patients (achieving Kt/V of >2.1). In another study of 84 CAPD patients from the same center, 76.2% of patients were assessed as being malnourished, with loss of appetite being an important etiological factor. Strategies to optimize dialysis dose, together with services of a renal dietician, will assist in improving the nutrition of patients with chronic renal failure.

Nutritional status in dialysis patients: a European consensus

BACKGROUND

Malnutrition is common in dialysis patients and closely related to morbidity and mortality. Therefore, assessment of nutritional status and nutritional management of dialysis patients play a central role in everyday nephrological practice.

METHODS

Achieving a consensus on key points relating to pathogenesis, clinical assessment, and nutritional management of dialysis patients.

RESULTS

The assessment of nutritional status should be based on clinical assessment and biochemical parameters, including history of weight loss, per cent standard weight, body mass index, muscle mass, subcutaneous fat mass, and plasma albumin, creatinine, bicarbonate and cholesterol. Co-morbid conditions should be assessed and C-reactive protein (CRP) measured--as a marker of inflammation--as there is a close relation between malnutrition, on one side, and co-morbid conditions and inflammation on the other. For a more detailed assessment, subjective global assessment of nutritional status is a well-validated tool, and dual-energy X-ray absorptiometry (DEXA) is a useful method for routine assessment of lean body mass. Anthropometric methods are also useful. They are cheap and easy to apply, although less precise than DEXA. The recommended daily protein intake is at least 1.2 g/kg standard body weight and the energy intake 35 kcal/kg standard body weight (BW), in patients <60 years, and 30 kcal/kg standard BW in patients >60 years. The standard bicarbonate level should be at least 22 mmol/l. If CRP is >10 mg/l, it is important to seek and treat the underlying cause. Adequate dialysis (for haemodialysis: Kt/V >1.2) should be ensured and, although no definite evidence of the importance of dialysis water quality is available, the opinion of the authors is that the water quality should be high. The role of the biocompatibility of the dialysis membrane is still not clear. The dietitian plays a pivotal role in the nutritional care of dialysis patients, and patients should be provided with dietary counselling from the start of substitutive treatment in order to meet the recommended nutritional intakes. Dietary counselling can also play an important role in an integrated treatment of hyperphosphataemia, although most patients will also need phosphate binders if they have an adequate protein intake.

CONCLUSION

Malnutrition assessment and treatment is a great challenge for nephrological care. Achieving evidence-based consensus can help in implementing the progress of knowledge in clinical practice.

The economics of daily dialysis

Research suggests that daily hemodialysis improves clinical outcomes and patient quality of life when compared with conventional hemodialysis; however, little is known about its economic impact. In this article, we review the literature on the costs of daily hemodialysis (n = 170). We also present updated results from an economic model we constructed that compares 1-year treatment costs for short daily in-center, short daily at-home, nocturnal, and conventional hemodialysis. Clinical parameters for the model were drawn from our review of the clinical literature. Resource use during daily hemodialysis was modeled after the experience of 2 ongoing programs in the United States, a short daily program in California (n = 26) and a nocturnal program in Virginia (n = 13). Reports from the literature and our economic model suggest daily hemodialysis might provide better outcomes and savings when compared with conventional hemodialysis. However, larger, longer controlled studies are needed to see if daily dialysis fulfills these promises. We discuss several issues researchers should keep in mind in designing future studies about the economics of daily dialysis.