Physical performance tasks were linked to the PROMIS physical function metric in patients undergoing hemodialysis

OBJECTIVES: To investigate whether a multi-item performance outcome measure, the physical performance test (PPT), can be calibrated to a common scale with patient-reported outcome measures, using the Patient-Reported Outcomes Measurement Information System (PROMIS) physical function (PF) metric. STUDY DESIGN AND SETTING: We analyzed baseline data (N = 1,113) from the CONVINCE study, an international trial in end-stage kidney disease patients comparing high-dose hemodiafiltration with high-flux hemodialysis. Assumptions of item response theory (IRT) modelling were investigated for the combined set of the nine-item PPT and a four-item PROMIS PF short form (PROMIS-PF4a). We applied unidimensional IRT linking for calibrating the PPT to the PROMIS PF metric. RESULTS: Although some evidence for multidimensionality was found, classical test statistics (Cronbach's Alpha = 0.93), Mokken (Loevinger's H = 0.50), and bifactor analysis (explained common variance = 0.65) indicated that PPT and PROMIS-PF4a items can be used to assess a common PF construct. On the group level, the agreement between PROMIS-PF4a and linked PPT scores was stable across several subsamples. On the individual level, scores differed considerably. CONCLUSION: We found preliminary evidence that the PPT can be linked to the PROMIS PF metric in hemodialysis patients, enabling group comparisons across patient-reported outcome and performance outcome measures. Alternative linking methods should be applied in future studies using a more comprehensive PROMIS PF item set

Why and how high volume hemodiafiltration may reduce cardiovascular mortality in stage 5 chronic kidney disease dialysis patients?: A comprehensive literature review on mechanisms involved

Online hemodiafiltration (HDF) is an established renal replacement modality for patients with end stage chronic kidney disease that is now gaining rapid clinical acceptance worldwide. Currently, there is a growing body of evidence indicating that treatment with HDF is associated with better outcomes and reduced cardiovascular mortality for dialysis patients. In this comprehensive review, we provide an update on the potential mechanisms which may improve survival in HDF treated patients. The strongest evidence is for better hemodynamic stability and reduced endothelial dysfunction associated with HDF treatments. Clinically, this is marked by a reduced incidence of intradialytic hypotensive episodes, with a better hemodynamic response to ultrafiltration, mediated by an increase in total peripheral vascular resistance and extra-vascular fluid recruitment, most likely driven by the negative thermal balance associated with online HDF therapy. In addition, endothelial function appears to be improved due to a combination of a reduction of the inflammatory and oxidative stress complex syndrome and exposure to circulating cardiovascular uremic toxins. Reports of reversed cardiovascular remodeling effects with HDF may be confounded by volume and blood pressure management, which are strongly linked to center clinical practices. Currently, treatment with HDF appears to improve the survival of dialysis patients predominantly due to a reduction in their cardiovascular burden, and this reduction is linked to the sessional convection volume exchanged

Why and how high volume hemodiafiltration may reduce cardiovascular mortality in stage 5 chronic kidney disease dialysis patients? A comprehensive literature review on mechanisms involved

Online hemodiafiltration (HDF) is an established renal replacement modality for patients with end stage chronic kidney disease that is now gaining rapid clinical acceptance worldwide. Currently, there is a growing body of evidence indicating that treatment with HDF is associated with better outcomes and reduced cardiovascular mortality for dialysis patients. In this comprehensive review, we provide an update on the potential mechanisms which may improve survival in HDF treated patients. The strongest evidence is for better hemodynamic stability and reduced endothelial dysfunction associated with HDF treatments. Clinically, this is marked by a reduced incidence of intradialytic hypotensive episodes, with a better hemodynamic response to ultrafiltration, mediated by an increase in total peripheral vascular resistance and extra-vascular fluid recruitment, most likely driven by the negative thermal balance associated with online HDF therapy. In addition, endothelial function appears to be improved due to a combination of a reduction of the inflammatory and oxidative stress complex syndrome and exposure to circulating cardiovascular uremic toxins. Reports of reversed cardiovascular remodeling effects with HDF may be confounded by volume and blood pressure management, which are strongly linked to center clinical practices. Currently, treatment with HDF appears to improve the survival of dialysis patients predominantly due to a reduction in their cardiovascular burden, and this reduction is linked to the sessional convection volume exchanged

Mortality in High-Flux Hemodialysis vs. High-Volume Hemodiafiltration in Colombian Clinical Practice: A Propensity Score Matching Study

Background: The aim was to compare the effects of high-flux hemodialysis (HF-HD) versus high-volume post-dilution hemodiafiltration (HV-HDF) on mortality risk. Methods: Retrospective observational study of prevalent patients on hemodialysis who were followed for two years and treated in 28 kidney centers in Colombia. In this study, we included all adult patients who had been on dialysis for at least 90 days treated with an arteriovenous fistula. They were classified as HF-HD if they underwent this treatment exclusively (100% of time). For HV-HDF, if they received this treatment in more than 90% of the observation period. The primary outcome variable was mortality, and the type of hemodialysis therapy was considered as the exposure variable. Propensity score matching (PSM) and Cox regression models were used to evaluate the effect of dialysis modality on the mortality risk. Results: A total of 2933 patients were analyzed, 2361 patients with HF-HD and 572 with HV-HDF. After PSM, 1010 prevalent patients remained; mortality rate was 14.2% (95% Confidence Interval—CI: 11.3–17.6%) and 5.9% (95%CI: 4.0–8.4%) in HF-HD and HV-HDF group, respectively. HV-HDF therapy was associated with a 55% reduction in mortality compared with the HF-HD group (Hazards ratio-HR: 0.45 [95%CI 0.32–0.64] p < 0.001). Cardiovascular mortality rate was not statistically different between groups (HF-HD: 7.1% (36), HV-HDF: 3.4% (17), HR: 0.51 (95%CI: 0.21–1.28), p: 0.152). However, in patients younger than 60 years, a beneficial effect was observed in favor to HV-HDF therapy with a 79% reduction in cardiovascular mortality risk (HR: 0.21, (95%CI: 0.05–0.79), p: 0.021). Conclusion: After adjustment for different confounders, this study suggests that HV-HDF could reduce all-cause mortality compared to HF-HD therapy in prevalent patients on hemodialysis

Acidosis and nutritional status in hemodialyzed patients. French Study Group for Nutrition in Dialysis.

International audienceIn a cross-sectional study of more than 30% of French dialysis patients (N = 7,123), we evaluated the relationships between predialysis plasma bicarbonate concentration and nutritional markers. Data including age, gender, cause of end-stage renal disease (ESRD), time on dialysis, body mass index (BMI), blood levels of midweek predialysis albumin, prealbumin, and bicarbonate were collected. Normalized protein catabolic rate (nPCR), dialysis adequacy parameters, and estimation of lean body mass (LBM) were computed from pre- and postbicarbonate-dialysis urea and creatinine levels according to the classical formulas of Garred. Average values (+/- 1 SD) were age 61 +/- 16 years, BMI 23.3 +/- 4.6 kg/m2, dialysis time 12.4 +/- 2.7 h/week, HCO3 22.8 +/- 3.5 mmol/L, albumin 38.7 +/- 5.3 g/L, prealbumin 340 +/- 90 mg/L, Kt/V 1.36 +/- 0.36, nPCR 1.13 +/- 0.32 g/kg BW/day, and LBM 0.86 +/- 0.21% of ideal LBM. A highly significant negative correlation was observed between predialysis bicarbonate levels (within a range of 16-30 mmol/L, 95% of this population) and nPCR confirmed by analysis of variance using bicarbonate classes (p < 0.0001). Bicarbonate was also negatively correlated with albumin, prealbumin, BMI, and LBM. No relationship was noted between bicarbonate and Kt/V despite a positive correlation between Kt/V and nPCR. It is likely that a persistent acidosis observed despite standard bicarbonate dialysis was caused by a high dietary protein intake which results in an increased acid load, but also overcomes the usual catabolic effects of acidosis

Beyond the cardiorenal anaemia syndrome:recognizing the role of iron deficiency

Growing awareness that heart failure, renal impairment, and anaemia are frequent co-morbidities which can exacerbate one another in a vicious circle of clinical deterioration has led to the concept of the cardiorenal anaemia syndrome (CRAS). The role of iron deficiency within this complex interplay has been less well examined. Scrutiny of data from the recent FAIR-HF trial raises a new hypothesis: is it time for oCRAS' to be supplemented with new acronyms such as CRIDS (cardiorenaliron deficiency syndrome) or even CRAIDS (cardiorenalanaemiairon deficiency syndrome)? Iron deficiency occurs frequently in heart failure patients with or without anaemia. It not only impairs oxygen transport through reduced erythropoiesis, but adversely affects oxidative metabolism, cellular energetics, and immune mechanisms, and the synthesis and degradation of complex molecules such as DNA. One large observational study in patients with heart failure found iron deficiency to be an independent predictor of death or urgent heart transplantation (hazard ratio 1.58, 95 confidence interval 1.142.17, P 0.005). In the FAIR-HF trial, i.v. iron therapy was associated with significant improvements in physical functioning in iron-deficient patients with heart failure, even in non-anaemic patients in whom haemoglobin levels did not change following i.v. iron administration. Key questions regarding the use of i.v. iron supplementation in the setting of heart failure merit exploration and could readily be answered by appropriately designed clinical trials. It is to be hoped that these important clinical trials are conducted, to permit a more subtle characterization of the patients pathological condition and interventional requirements