Prevalence, patient burden and physicians' perception of pruritus in haemodialysis patients

BACKGROUND

Chronic kidney disease-associated pruritus (CKD-aP) is an underrated symptom in patients with impaired kidney function. The present study assessed the prevalence, impact on quality of life (QoL) and risk factors for CKD-aP in a contemporary national cohort of patients on haemodialysis. In addition, we evaluated attending physicians' awareness and approach to therapy.

METHODS

Validated patient's and physician's questionnaires on pruritus severity and QoL were used in combination with information obtained by the Austrian Dialysis and Transplant Registry.

RESULTS

The prevalence of mild, moderate and severe pruritus in 962 observed patients was 34.4%, 11.4% and 4.3%. Physicians' estimated prevalence values were 25.0 (95% CI 16.8-33.2), 14.4 (11.3-17.6) and 6.3% (4.9-8.3), respectively. The estimated national prevalence estimate extrapolated from the observed patients was 45.0% (95% CI 39.5-51.2) for any, 13.9% (95% CI 10.6-17.2) for moderate and 4.2% (95% CI 2.1-6.2) for severe CKD-aP. CKD-aP severity was significantly associated with impaired QoL. Risk factors for moderate-severe pruritus were higher C-reactive protein [odds ratio (OR) 1.61 (95% CI 1.07-2.43)] and parathyroid hormone (PTH) values [OR 1.50 (95% CI 1.00-2.27)]. Therapy for CKD-aP included changes in the dialysis regimen, topical treatments, antihistamines, gabapentin and pregabalin and phototherapy in a majority of centres.

CONCLUSIONS

While the overall prevalence of CKD-aP in our study is similar to that in previously published literature, the prevalence of moderate-severe pruritus is lower. CKD-aP was associated with reduced QoL and elevated markers of inflammation and PTH. The high awareness of CKD-aP in Austrian nephrologists may explain the lower prevalence of more severe pruritus.

Diastolic function in chronic kidney disease

Chronic kidney disease (CKD) is characterized by clustered age-independent concentric left ventricular (LV) geometry, geometry-independent systolic dysfunction and age and heart rate-independent diastolic dysfunction. Concentric LV geometry is always associated with echocardiographic markers of abnormal LV relaxation and increased myocardial stiffness, two hallmarks of diastolic dysfunction. Non-haemodynamic mechanisms such as metabolic and electrolyte abnormalities, activation of biological pathways and chronic exposure to cytokine cascade and the myocardial macrophage system also impact myocardial structure and impair the architecture of the myocardial scaffold, producing and increasing reactive fibrosis and altering myocardial distensibility. This review addresses the pathophysiology of diastole in CKD and its relations with cardiac mechanics, haemodynamic loading, structural conditions, non-haemodynamic factors and metabolic characteristics. The three mechanisms of diastole will be examined: elastic recoil, active relaxation and passive distensibility and filling. Based on current evidence, we briefly provide methods for quantification of diastolic function and discuss whether diastolic dysfunction represents a distinct characteristic in CKD or a proxy of the severity of the cardiovascular condition, with the potential to be predicted by the general cardiovascular phenotype. Finally, the review discusses assessment of diastolic function in the context of CKD, with special emphasis on end-stage kidney disease, to indicate whether and when in-depth measurements might be helpful for clinical decision making in this context.

Results of the European EDITH nephrologist survey on factors influencing treatment modality choice for end-stage kidney disease

BACKGROUND

Access to forms of dialysis, kidney transplantation (Tx) and comprehensive conservative management (CCM) for patients with end-stage kidney disease (ESKD) varies across European countries. Attitudes of nephrologists, information provision and decision-making may influence this access and nephrologists may experience several barriers when providing treatments for ESKD.

METHODS

We surveyed European nephrologists and kidney transplant surgeons treating adults with ESKD about factors influencing modality choice. Descriptive statistics were used to compare the opinions of professionals from European countries with low-, middle- and high-gross domestic product purchasing power parity (GDP PPP).

RESULTS

In total, 681 professionals from 33 European countries participated. Respondents from all GDP categories indicated that ∼10% of patients received no information before the start of renal replacement therapy (RRT) (P = 0.106). Early information provision and more involvement of patients in decision-making were more frequently reported in middle- and high-GDP countries (P < 0.05). Professionals' attitudes towards several treatments became more positive with increasing GDP (P < 0.05). Uptake of in-centre haemodialysis was sufficient to 73% of respondents, but many wanted increased uptake of home dialysis, Tx and CCM. Respondents experienced different barriers according to availability of specific treatments in their centre. The occurrence of barriers (financial, staff shortage, lack of space/supplies and patient related) decreased with increasing GDP (P < 0.05).

CONCLUSIONS

Differences in factors influencing modality choice when providing RRT or CCM to adults with ESKD were found among low-, middle- and high-GDP countries in Europe. Therefore a unique pan-European policy to improve access to treatments may be inefficient. Different policies for clusters of countries could be more useful.

[Acute severe respiratory distress in chronic haemodialytic patients affected by SARS-CoV-2 pneumonia: prevalence and associated factors. A single-centre experience from Cardarelli Hospital in Naples (Italy)]

Background: SARS‑CoV‑2-induced severe acute respiratory syndrome is associated with high mortality in the general population; however, the data on chronic haemodialysis (HD) patients are currently scarce. Methods: We performed a retrospective analysis to evaluate the onset of acute respiratory distress syndrome (ARDS) in patients with SARS‑CoV‑2-induced interstitial pneumonia diagnosed by PCR test and detected by high resolution computed tomography (HRCT). For each patient, we calculated a CT score between 0 and 24, based on the severity of pneumonia. The primary outcome was the onset of ARDS, detected by P/F ratio >200. We included 57/90 HD patients (age: 66.5 ±13.4 years, 61.4 % males, 42.1% diabetics, 52.6% CV disease) treated at the Cardarelli Hospital in Naples (Italy) from 1st September 2020 to 31st March 2021. All patients were treated with intermittent HD. Results: Patients who experienced ARDS had a more severe pneumonia (CT score: 15 [C.I.95%:10-21] in ARDS patients vs 7 [C.I.95%: 1-16] in no ARDS; P=0.015). Logistic regression showed that the CT score was the main factor associated with the onset of ARDS (1.12; 95% c.i.: 1.00-1.25), independently from age, gender, diabetes, chronic obstructive pulmonary disease, and prior CV disease. Thirty-day mortality was much greater in ARDS patients (83,3%) than in no-ARDS (19.3%). Conclusions: This retrospective analysis highlights that HD patients affected by SARS-CoV-2 pneumonia show an increased risk of developing ARDS, dependent on the severity of CT at presentation. This underlines once again the need for prevention strategies, in primis the vaccination campaign, for these frail patients.

Hypoalbuminaemia and One-Year Mortality in Haemodialysis Patients with Heart Failure: A Cohort Analysis

INTRODUCTION

The prevalence of chronic kidney disease (CKD) and heart failure (HF) has been rising over the past decade, with a prevalence close to 40%. Cardiovascular disease and malnutrition are common comorbidities and known risk factors for mortality in haemodialysis (HD) patients. We aimed to evaluate the one-year mortality rate after dialysis induction, and the impact of serum albumin levels on survival outcomes, in patients with CKD and HF.

METHODS

This was a retrospective analysis of patients with CKD and HF who underwent chronic HD between January 2016 and December 2019 in a tertiary-care Portuguese hospital. Variables were submitted to univariate and multivariate analysis to determine factors predictive of one-mortality after HD start.

RESULTS

In total, 204 patients were analysed (mean age 75.1 ± 10.3 years). Within the first year of HD start, 28.7% of patients died. These patients were significantly older [79.8 ± 7.2 versus 72.9 ± 10.9 years, p < 0.001; OR 1.08 (1.04-1.13), p < 0.001] and had a higher mean Charlson Index [9.0 ± 1.8 versus 8.3 ± 2.0, p = 0.015; OR 1.22 (1.04-1.44), p = 0.017], lower serum creatinine [5.1 ± 1.6 mg/dL versus 5.8 ± 2.0 mg/dL; p = 0.021; OR 0.80 (0.65-0.97), p = 0.022], lower albumin levels [3.1 ± 0.6 g/dL versus 3.4 ± 0.6 g/dL, p < 0.001; OR 0.38 (0.22-0.66), p = 0.001] and started haemodialysis with a central venous catheter more frequently [80.4% versus 66.2%, p = 0.050]. Multivariate analysis identified older age [aOR 1.07 (1.03-1.12), p = 0.002], lower serum creatinine [aOR 0.80 (0.64-0.99), p = 0.049] and lower serum albumin [aOR 0.41 (0.22-0.75), p = 0.004] as predictors of one-year mortality.

CONCLUSION

In our cohort, older age, lower serum creatinine and lower serum albumin were independent risk factors for one-year mortality, highlighting the prognostic importance of malnutrition in patients starting chronic HD.

Dynapaenia and sarcopaenia in chronic haemodialysis patients: do muscle weakness and atrophy similarly influence poor outcome?

BACKGROUND

Sarcopaenia, defined as a decline in both muscle mass and function, has been recognized as a major determinant of poor outcome in haemodialysis (HD) patients. It is generally assumed that sarcopaenia is driven by muscle atrophy related to protein-energy wasting. However, dynapaenia, defined as weakness without atrophy, has been characterized by a different disease phenotype from sarcopaenia. The aim of this study was to compare the characteristics and prognosis of sarcopaenic and dynapaenic patients among a prospective cohort of chronic HD (CHD) patients.

METHODS

Two hundred and thirty-two CHD patients were enrolled from January to July 2016 and then followed prospectively until December 2018. At inclusion, weakness and atrophy were, respectively, evaluated by maximal voluntary force (MVF) and creatinine index (CI). Sarcopaenia was defined as the association of weakness and atrophy (MVF and CI below the median) while dynapaenia was defined as weakness not related to atrophy (MVF below the median, and CI above the median).

RESULTS

From a total of 187 prevalent CHD patients [65% of men, age 65.3 (49.7-82.0) years], 44 died during the follow-up period of 23.7 (12.4-34.9) months. Sarcopaenia and dynapaenia were observed in 33.7 and 16% of the patients, respectively. Compared with patients with sarcopaenia, patients with dynapaenia were younger and with a lower Charlson score. In contrast, mortality rate was similar in both groups (38 and 27%, respectively). After adjustment for age, sex, lean tissue index, serum albumin, high-sensitivity C-reactive protein (hs-CRP), haemoglobin (Hb), normalized protein catabolic rate (nPCR), dialysis vintage and Charlson score, only patients with dynapaenia were at increased risk of death [hazard ratio (HR) = 2.99, confidence interval 1.18-7.61; P = 0.02].

CONCLUSIONS

Screening for muscle functionality is highly warranted to identify patients with muscle functional impairment without muscle atrophy. In contrast to sarcopaenia, dynapaenia should appear as a phenotype induced by uraemic milieu, characterized by young patients with low Charlson score and poor prognosis outcome independently of serum albumin, hs-CRP, Hb, nPCR and dialysis vintage.

How biocompatible haemodialysers can conquer the need for systemic anticoagulation even in post-dilution haemodiafiltration: a cross-over study

Background

While systemic anticoagulation is most widely used in haemodialysis (HD), contraindications to its use might occur in particular settings. The Solacea^™ haemodialyser with an asymmetric triacetate membrane claims improved biocompatibility and has already shown promising results when used in combination with only half dose of anticoagulation. To quantify the performance of the Solacea^™ when further decreasing anticoagulation to zero, fibre blocking was assessed by micro-computed tomography (micro-CT).

Methods

Ten maintenance HD patients underwent six dialysis sessions at midweek using a Solacea^™ 19H dialyser, consecutively in pre-dilution haemodiafiltration (pre-HDF), HD and post-dilution HDF (post-HDF). After the first three sessions with only a quarter of their regular anticoagulation dose (one-quarter), the last three sessions were performed without anticoagulation (zero). Dialyser fibre blocking was quantified in the dialyser outlet potting using a 3D micro-CT scanning technique post-dialysis.

Results

Even in case of reduced (one-quarter) anticoagulation, the relative number of open fibres post-dialysis was almost optimal, i.e. 0.96 (0.87-0.99) with pre-HDF, 0.99 (0.97-0.99) with HD and 0.97 (0.92-0.99) with post-HDF. Fibre patency was mildly decreased for pre-HDF and HD when anticoagulation was decreased from one-quarter to zero, i.e. to 0.76 (0.61-0.85) with pre-HDF (P = 0.004) and to 0.80 (0.77-0.89) with HD (P = 0.013). Comparing the results for zero anticoagulation, post-HDF [i.e. 0.94 (0.82-0.97)] performed as well as HD and pre-HDF.

Conclusions

The Solacea^™ dialyser provides promising results for use in conditions where systemic anticoagulation is contraindicated. Post-HDF, although inducing haemoconcentration in the dialyser, is equally effective for fibre patency in case of zero anticoagulation as pre-HDF and HD when using Solacea^™.

Predictors of in-hospital mortality in patients with infective endocarditis

BACKGROUND

Infective endocarditis is a serious septic disease, and the epidemiological profile has changed over the last decade. However, there is a paucity of data regarding the current outcome and predictor of in-hospital mortality in patients with infective endocarditis.

METHODS

Consecutive patients diagnosed as infective endocarditis based on the modified Duke criteria at Kansai Medical University hospital from January 2006 to June 2019 were prospectively included. The primary outcome was in-hospital mortality. Cox proportional hazards modelling was used to assess risk factors of in-hospital mortality.

RESULTS

Of 137 consecutive patients with infective endocarditis (age 60 ± 17 years-old, 62% men, 65% underlying cardiac disease, 11% chronic haemodialysis), 18 (13%) died during hospitalisation. Age and sex were not associated with in-hospital mortality. Patients on chronic haemodialysis exhibited significantly higher in-hospital mortality rate than those without (47 vs. 9%). After adjusting for comorbidities in a multivariate Cox proportional hazards model, chronic haemodialysis was a significant predictor of in-hospital mortality [hazard ratio (HR) 4.22, 95% confidential interval (CI): 1.49-12.0, p < 0.01], independently of C-reactive protein (per 1 mg/dl; HR 1.07, 95%CI: 1.02-1.12, p < 0.05).

CONCLUSIONS

Infective endocarditis in patients on chronic haemodialysis is a serious life-threatening condition that requires early diagnosis and an effective therapeutic approach.

Identifying key predictors of mortality in young patients on chronic haemodialysis-a machine learning approach

BACKGROUND

The mortality risk remains significant in paediatric and adult patients on chronic haemodialysis (HD) treatment. We aimed to identify factors associated with mortality in patients who started HD as children and continued HD as adults.

METHODS

The data originated from a cohort of patients <30 years of age who started HD in childhood (≤19 years) on thrice-weekly HD in outpatient DaVita dialysis centres between 2004 and 2016. Patients with at least 5 years of follow-up since the initiation of HD or death within 5 years were included; 105 variables relating to demographics, HD treatment and laboratory measurements were evaluated as predictors of 5-year mortality utilizing a machine learning approach (random forest).

RESULTS

A total of 363 patients were included in the analysis, with 84 patients having started HD at <12 years of age. Low albumin and elevated lactate dehydrogenase (LDH) were the two most important predictors of 5-year mortality. Other predictors included elevated red blood cell distribution width or blood pressure and decreased red blood cell count, haemoglobin, albumin:globulin ratio, ultrafiltration rate, z-score weight for age or single-pool Kt/V (below target). Mortality was predicted with an accuracy of 81%.

CONCLUSIONS

Mortality in paediatric and young adult patients on chronic HD is associated with multifactorial markers of nutrition, inflammation, anaemia and dialysis dose. This highlights the importance of multimodal intervention strategies besides adequate HD treatment as determined by Kt/V alone. The association with elevated LDH was not previously reported and may indicate the relevance of blood-membrane interactions, organ malperfusion or haematologic and metabolic changes during maintenance HD in this population.

Urgent-start dialysis in patients referred early to a nephrologist-the CKD-REIN prospective cohort study

BACKGROUND

The lack of a well-designed prospective study of the determinants of urgent dialysis start led us to investigate its individual- and provider-related factors in patients seeing nephrologists.

METHODS

The Chronic Kidney Disease Renal Epidemiology and Information Network (CKD-REIN) is a prospective cohort study that included 3033 patients with CKD [mean age 67 years, 65% men, mean estimated glomerular filtration rate (eGFR) 32 mL/min/1.73 m2] from 40 nationally representative nephrology clinics from 2013 to 2016 who were followed annually through 2020. Urgent-start dialysis was defined as that 'initiated imminently or <48 hours after presentation to correct life-threatening manifestations' according to the Kidney Disease: Improving Global Outcomes 2018 definition.

RESULTS

Over a 4-year (interquartile range 3.0-4.8) median follow-up, 541 patients initiated dialysis with a known start status and 86 (16%) were identified with urgent starts. The 5-year risks for the competing events of urgent and non-urgent dialysis start, pre-emptive transplantation and death were 4, 17, 3 and 15%, respectively. Fluid overload, electrolytic disorders, acute kidney injury and post-surgery kidney function worsening were the reasons most frequently reported for urgent-start dialysis. Adjusted odds ratios for urgent start were significantly higher in patients living alone {2.14 [95% confidence interval (CI) 1.08-4.25] or with low health literacy [2.22 (95% CI 1.28-3.84)], heart failure [2.60 (95% CI 1.47-4.57)] or hyperpolypharmacy [taking >10 drugs; 2.14 (95% CI 1.17-3.90)], but not with age or lower eGFR at initiation. They were lower in patients with planned dialysis modality [0.46 (95% CI 0.19-1.10)] and more nephrologist visits in the 12 months before dialysis [0.81 (95% CI 0.70-0.94)] for each visit.

CONCLUSIONS

This study highlights several patient- and provider-level factors that are important to address to reduce the burden of urgent-start dialysis.

Non-medical barriers reported by nephrologists when providing renal replacement therapy or comprehensive conservative management to end-stage kidney disease patients: a systematic review

BACKGROUND

Large international differences exist in access to renal replacement therapy (RRT) modalities and comprehensive conservative management (CCM) for patients with end-stage kidney disease (ESKD), suggesting that some patients are not receiving the most appropriate treatment. Previous studies mainly focused on barriers reported by patients or medical barriers (e.g. comorbidities) reported by nephrologists. An overview of the non-medical barriers reported by nephrologists when providing the most appropriate form of RRT (other than conventional in-centre haemodialysis) or CCM is lacking.

METHODS

We searched in EMBASE and PubMed for original articles with a cross-sectional design (surveys, interviews or focus groups) published between January 2010 and September 2018. We included studies in which nephrologists reported barriers when providing RRT or CCM to adult patients with ESKD. We used the barriers and facilitators survey by Peters et al. [Ruimte Voor Verandering? Knelpunten en Mogelijkheden Voor Verbeteringen in de Patiëntenzorg. Nijmegen: Afdeling Kwaliteit van zorg (WOK), 2003] as preliminary framework to create our own model and performed meta-ethnographic analysis of non-medical barriers in text, tables and figures.

RESULTS

Of the 5973 articles screened, 16 articles were included using surveys (n = 10), interviews (n = 5) and focus groups (n = 1). We categorized the barriers into three levels: patient level (e.g. attitude, role perception, motivation, knowledge and socio-cultural background), level of the healthcare professional (e.g. fears and concerns, working style, communication skills) and level of the healthcare system (e.g. financial barriers, supportive staff and practice organization).

CONCLUSIONS

Our systematic review has identified a number of modifiable, non-medical barriers that could be targeted by, for example, education and optimizing financing structure to improve access to RRT modalities and CCM.

Survival with low- and high-flux dialysis

Background

Besides advances in haemodialysis (HD), mortality rates are still high. The effect of the different types of HD membranes on survival is still a controversial issue. The aim of this COSMOS (Current management Of Secondary hyperparathyroidism: a Multicentre Observational Study) analysis was to survey, in HD patients, the relationship between the use of conventional low- or high-flux membranes and all-cause and cardiovascular mortality.

Methods

COSMOS is a multicentre, open-cohort, 3-year prospective study, designed to evaluate mineral and bone disorders in the European HD population. The present analysis included 5138 HD patients from 20 European countries, 3502 randomly selected at baseline (68.2%), plus 1636 new patients with <1 year on HD (31.8%) recruited to replace patients who died, were transplanted, switched to peritoneal dialysis or lost to follow-up by other reasons. Cox-regression analysis with time-dependent variables, propensity score matching and the use of an instrumental variable (facility-level analysis) were used.

Results

After adjustments using three different multivariate models, patients treated with high-flux membranes showed a lower all-cause and cardiovascular mortality risks {hazard ratio (HR) = 0.76 [95% confidence interval (CI) 0.61-0.96] and HR = 0.61 (95% CI 0.42-0.87), respectively}, that remained significant after matching by propensity score for all-cause mortality (HR = 0.69, 95% CI 0.52-0.93). However, a facility-level analysis showed no association between the case-mix-adjusted facility percentage of patients dialysed with high-flux membranes and all-cause and cardiovascular mortality.

Conclusions

High-flux dialysis was associated with a lower relative risk of all-cause and cardiovascular mortality. However, dialysis facilities using these dialysis membranes to a greater extent did not show better survival.

Association of changes in bone mineral parameters with mortality in haemodialysis patients: insights from the ARO cohort

BACKGROUND

There is little information in haemodialysis (HD) patients on whether temporal changes in serum calcium, phosphate or intact parathyroid hormone (iPTH) are associated with mortality.

METHODS

We analysed associations of phosphate, total calcium and iPTH with all-cause and cardiovascular mortality in 8817 incident HD patients from the European second Analyzing Data, Recognizing Excellence and Optimizing Outcomes (AROii) cohort enrolled in 2007-09, which were prospectively followed for a median of 3 years, using time-dependent Cox proportional hazards models. We evaluated changes in risk over time depending on changes in phosphate, calcium or iPTH.

RESULTS

The association of phosphate and iPTH with all-cause mortality was U-shaped, with the lowest risk ranges between 1.20 and 1.89 mmol/L for phosphate and between 239 and 710 ng/L for iPTH. For total calcium, the associations were J-shaped, with an increased risk for all-cause mortality at levels >2.36 mmol/L. Lowest risk ranges for cardiovascular mortality did not change markedly for all three parameters. If iPTH was below the lowest risk range at baseline (iPTH <239 ng/L), a subsequent increase in levels was associated with improved survival. For phosphate, an increase or decrease out of the lowest risk range was associated with increased mortality risk. For calcium, this was only the case when the values increased above the lowest risk range.

CONCLUSION

In the AROii cohort, the ranges of bone mineral biomarkers associated with the lowest mortality ranges were largely consistent with the current Kidney Disease: Improving Global Outcomes chronic kidney disease-mineral and bone disorder guideline recommendations. Allowing a suppressed iPTH to increase was associated with a lower mortality, whereas shifts of phosphate or calcium outside the lowest risk range increased mortality.

Vitamin K antagonist has a higher impact than heparin in preventing circuit clotting in chronic haemodialysis patients

Background

In dialysis sessions, some data suggest that decreasing or even avoiding additional anticoagulation by heparin is possible among patients already treated with oral anticoagulation. However, the required dose of heparin may actually depend on the pre-dialysis international normalized ratio (INR), which varies from one session to another. The aim of our study was to determine the respective role of INR and heparin dosing in the risk of circuit clotting during chronic haemodialysis.

Methods

From early 2012 to July 2016, we analysed the totality of dialysis sessions performed at Brest University Hospital among haemodialysis patients treated by vitamin K antagonists (VKA). We established a prediction of circuit clotting on the basis of a simplified score obtained by combining INR and heparin dosing.

Results

In total, 7184 dialysis sessions among chronic haemodialysis patients under VKA were identified, including 233 with clotting events. The mean INR without clotting events was 2.5 versus 1.8 with clotting events (P < 0.001). Frequencies of circuit clotting were different according to INR group (INR <2.0, INR 2.0-3.0, INR >3.0; P < 0.0001). The protective role of VKA was higher than heparin, as shown by discriminant factor analysis (P < 0.0001). Conclusion. Our study established a predictive model of thrombosis risk of dialysis circuits in patients treated by VKA for a given heparin dose and a given INR. This model shows a marginal contribution of heparin to protect against the risk of thrombosis compared with VKA. Moreover, heparin would not appear to be necessary for patients with an INR >2.2.

Initiation of sodium polystyrene sulphonate and the risk of gastrointestinal adverse events in advanced chronic kidney disease: a nationwide study

BACKGROUND

Despite long-standing clinical use of sodium polystyrene sulphonate (SPS) for hyperkalaemia management in chronic kidney disease (CKD), its safety profile remains poorly investigated.

METHODS

We undertook an observational analysis of nephrology-referred adults with incident CKD Stage 4+ in Sweden during 2006-16 and with no previous SPS use. We studied patterns of use and adverse events associated to SPS initiation during follow-up. Patterns of SPS use were defined by chronicity of treatment and by prescribed dose. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) associated with SPS initiation (time-varying exposure) for the risk of severe (intestinal ischaemia, thrombosis or ulceration/perforation) and minor (de novo dispensation of laxatives or anti-diarrheal drugs) gastrointestinal (GI) events.

RESULTS

Of 19 530 SPS-naïve patients with CKD, 3690 initiated SPS during follow-up. A total of 59% took SPS chronically, with an average of three dispensations/year. The majority (85%) were prescribed lower dosages than specified on the product label. During follow-up, 202 severe and 1149 minor GI events were recorded. SPS initiation was associated with a higher incidence of severe adverse events [adjusted HR 1.25 95% CI 1.05-1.49)], particularly in those receiving per label doses [1.54 (1.09-2.17)] and mainly attributed to ulcers and perforations. SPS initiation was also associated with higher incidence of minor GI events [adjusted HR 1.11 (95% CI 1.03-1.19)], regardless of dose, and mainly accounted for by de novo dispensation of laxatives.

CONCLUSIONS

Initiation of SPS in patients with advanced CKD is associated with a higher risk of severe GI complications as well as the initiation of GI-related medications, particularly when prescribed at per label doses.

Change in FGF23 concentration over time and its association with all-cause mortality in patients treated with haemodialysis or haemodiafiltration

Background

Previous studies in patients on haemodialysis (HD) have shown an association of fibroblast growth factor 23 (FGF23) with all-cause mortality. As of yet, the result of FGF23 lowering on mortality is unknown in this population.

Methods

FGF23 was measured in a subset of 404 patients from the Dutch CONvective TRansport STudy (CONTRAST study) [a randomized trial in prevalent dialysis patients comparing HD and haemodiafiltration (HDF) with clinical outcome] at baseline and Months 6 and 12. A substantial decline of FGF23 change over time was anticipated in patients randomized to HDF since HDF induces higher dialytic clearance of FGF23. The associations of both baseline FGF23 and 6-months change in FGF23 with all-cause mortality were analysed. In addition, the difference in FGF23 change between HD and HDF was explored. Furthermore, the role of dialysis modality in the association between FGF23 change and outcome was analysed.

Results

No association was observed between quartiles of baseline FGF23 and all-cause mortality. Over 6 months, FGF23 declined in patients on HDF, whereas FGF23 remained stable in patients on HD. A decrease in FGF23 was not associated with improved survival compared with a stable FGF23 concentration. However, increasing FGF23 was associated with a significantly higher mortality risk, both in crude and fully adjusted models [hazard ratio 2.01 (95% confidence interval 1.30–3.09)].

Conclusion

Whereas no association between a single value of FGF23 and all-cause mortality was found, increasing FGF23 concentrations did identify patients at risk for mortality. Since lowering FGF23 did not improve outcome, this study found no argument for therapeutically lowering FGF23.

Serum phosphate optimal timing and range associated with patients survival in haemodialysis: the COSMOS study

BACKGROUND

Serum phosphate is a key parameter in the management of chronic kidney disease-mineral and bone disorder (CKD-MBD). The timing of phosphate measurement is not standardized in the current guidelines. Since the optimal range of these biomarkers may vary depending on the duration of the interdialytic interval, in this analysis of the Current management of secondary hyperparathyroidism: a multicentre observational study (COSMOS), we assessed the influence of a 2- (midweek) or 3-day (post-weekend) dialysis interval for blood withdrawal on serum levels of CKD-MBD biomarkers and their association with mortality risk.

METHODS

The COSMOS cohort (6797 patients, CKD Stage 5D) was divided into two groups depending upon midweek or post-weekend blood collection. Univariate and multivariate Cox's models adjusted hazard ratios (HRs) by demographics and comorbidities, treatments and biochemical parameters from a patient/centre database collected at baseline and every 6 months for 3 years.

RESULTS

There were no differences in serum calcium or parathyroid hormone levels between midweek and post-weekend patients. However, in post-weekend patients, the mean serum phosphate levels were higher compared with midweek patients (5.5 ± 1.4 versus 5.2 ± 1.4 mg/dL, P < 0.001). Also, the range of serum phosphate with the lowest mortality risk [HR ≤ 1.1; midweek: 3.5-4.9 mg/dL (95% confidence interval, CI: 2.9-5.2 mg/dL); post-weekend: 3.8-5.7 mg/dL (95% CI: 3.0-6.4 mg/dL)] showed significant differences in the upper limit (P = 0.021).

CONCLUSION

Midweek and post-weekend serum phosphate levels and their target ranges associated with the lowest mortality risk differ. Thus, clinical guidelines should consider the timing of blood withdrawal when recommending optimal target ranges for serum phosphate and therapeutic strategies for phosphate control.

Influence of gender and age on haemodialysis practices: a European multicentre analysis

Background

Women of all ages and elderly patients of both genders comprise an increasing proportion of the haemodialysis population. Worldwide, significant differences in practice patterns and treatment results exist between genders and among younger versus older patients. Although efforts to mitigate sex-based differences have been attempted, significant disparities still exist.

Methods

This retrospective cohort study included all 1247 prevalent haemodialysis patients in DaVita units in Portugal (five dialysis centres, n = 730) and Poland (seven centres, n = 517). Demographic data, dialysis practice patterns, vascular access prevalence and the achievement of a variety of Kidney Disease: Improving Global Outcomes (KDIGO) treatment targets were evaluated in relation to gender and age groups.

Results

Body weight and the prescribed dialysis blood flow rate were lower in women (P < 0.001), whereas treated blood volume per kilogram per session was higher (P < 0.01), resulting in higher single-pool Kt/V in women than in men (P < 0.001). Haemoglobin was significantly higher in men (P = 0.01), but the proportion of patients within target range (10–12 g/dL) was similar. Men more often had an arteriovenous fistula than women (80% versus 73%; P < 0.01) with a similar percentage of central venous catheters. There were no gender-specific differences in terms of dialysis adequacy, anaemia parameters or mineral and bone disorder parameters, or in the attainment of KDIGO targets between women and men >80 years of age.

Conclusions

This large, multicentre real-world analysis indicates that haemodialysis practices and treatment targets are similar for women and men, including the most elderly, in DaVita haemodialysis clinics in Europe.

A new technique for measuring fistula flow using venous blood gas oxygen saturation in patients with a central venous catheter

Background

Doppler ultrasound (DU) monitoring early after arteriovenous fistula (AVF) creation allows the identification of low blood flow (Qa) requiring prompt revision, but it is costly (needs skilled operators and technical instruments) and is not available in all dialysis units. Therefore alternative first-line methods to measure Qa would be welcomed. We reasoned that once an AVF is created, an increment in central venous oxygen saturation (ScvO₂) is predictable and proportional to Qa.

Methods

Accordingly, in patients receiving dialysis through a central venous catheter (CVC) in whom an AVF was created, we measured, by means of blood gas analysis, the ScvO₂ increment before and after manual compression of the arteriovenous shunt and verified its correlation with DU-measured Qa.

Results

We sampled blood gas in 18 patients with CVC and AVF before and after 30 s manual compression of the AVF. ScvO₂ averaged 70.5 ± 3% before and 65.2 ± 3% after AVF closure, with an average drop of 5.1 ± 3% (range 1-12). AVF Qa, which was measured within 24 h by means of DU, averaged 635 ± 349 mL/min (range 50-1300) and was strictly and positively correlated with ΔScvO₂ (r = 0.954, P < 0.0001).

Conclusions

Therefore we suggest that in patients with CVC and a newly created AVF, it is possible to monitor AVF Qa without DU by simply measuring blood gas and ΔScvO₂. This technique is simple, cheap, repeatable, non-invasive and operator independent and represents a new useful screening test to detect delayed AVF access maturation deserving prompt DU measurement and surgical revision. It helps to quickly identify patients in urgent need of DU verification and possible surgical revision. Regrettably, it is applicable only in patients with CVC.

Arteriovenous fistula thrombosis is associated with increased all-cause and cardiovascular mortality in haemodialysis patients from the AURORA trial

Background

The impact of arteriovenous fistula (AVF) or graft (AVG) thrombosis on mortality has been sparsely studied. This study investigated the association between AVF/AVG thrombosis and all-cause and cardiovascular mortality.

Methods

The data from 2439 patients with AVF or AVG undergoing maintenance haemodialysis (HD) included in the A Study to Evaluate the Use of Rosuvastatin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events trial (AURORA) were analysed using a time-dependent Cox model. The incidence of vascular access (VA) thrombosis was a pre-specified secondary outcome.

Results

During follow-up, 278 AVF and 94 AVG thromboses were documented. VA was restored at 22 ± 64 days after thrombosis (27 patients had no restoration with subsequent permanent central catheter). In multivariable survival analysis adjusted for potential confounders, the occurrence of AVF/AVG thrombosis was associated with increased early and late all-cause mortality, with a more pronounced association with early all-cause mortality {hazard ratio [HR] < 90 days 2.70 [95% confidence interval (CI) 1.83–3.97], P < 0.001; HR > 90 days 1.47 [1.20–1.80], P < 0.001}. In addition, the occurrence of AVF thrombosis was significantly associated with higher all-cause mortality, whether VA was restored within 7 days [HR 1.34 (95% CI 1.02–1.75), P = 0.036] or later than 7 days [HR 1.81 (95% CI 1.29–2.53), P = 0.001].

Conclusions

AVF/AVG thrombosis should be considered as a major clinical event since it is strongly associated with increased mortality in patients on maintenance HD, especially in the first 90 days after the event and when access restoration occurs >7 days after thrombosis. Clinicians should pay particular attention to the timing of VA restoration and the management of these patients during this high-risk period. The potential benefit of targeting overall patient risk with more aggressive treatment after AVF/AVG restoration should be further explored.

Evaluation of the efficacy of a medium cut-off dialyser and comparison with other high-flux dialysers in conventional haemodialysis and online haemodiafiltration

BACKGROUND

Online haemodiafiltration (OL-HDF) has been shown to reduce all-cause mortality versus conventional haemodialysis (HD); however, it is not always available. In these situations, a novel class of membranes with a higher pore size, medium cut-off (MCO) dialysers, could be promising. The aim of this study is to evaluate the efficacy of an MCO dialyser in the removal of small and medium-size molecules and compare it with standard high-flux (HF) dialysers in HD and OL-HDF.

METHODS

In this crossover study, 18 prevalent HD patients were studied in three single mid-week dialysis treatments during three consecutive weeks as follows: first week with OL-HDF with a standard HF dialyser, second week with conventional HD with a standard HF dialyser and third week with conventional HD with an MCO dialyser. Reduction ratios (RRs) of different-sized molecules and albumin losses were collected for the different dialysers.

RESULTS

MCO HD provided a greater reduction of middle and larger middle molecules compared with standard HF HD [rate reduction (RR) β2-microglobulin 74.7% versus 69.7%, P=0.01; RR myoglobin 62.5% versus 34.3%, P=0.001; RR prolactin 60% versus 32.8%, P=0.001; RR α1-glycoprotein 2.8% versus -0.1%, P=0.01]. We found no difference in the clearance of small and larger middle molecules comparing MCO HD with OL-HDF. Albumin losses were 0.03  g/session with MCO HD and 3.1  g/session with OL-HDF (P=0.001).

CONCLUSION

MCO HD is superior to standard HF HD in the removal of middle and larger middle molecules and it is not inferior to OL-HDF in the clearance of small and larger middle molecules. Thus it could be an alternative in patients in which it is not possible to perform OL-HDF.

Hyperkalaemia prevalence, recurrence and management in chronic haemodialysis: a prospective multicentre French regional registry 2-year survey

Background

Observational studies have reported increased mortality rates in hyperkalaemic or hypokalaemic chronic haemodialysis patients. This study assessed the prevalence and recurrence of hyperkalaemia (HK) along with the concomitant prescription of low-potassium (K) dialysis baths and of K-binding agents in a registry within a French regional disease management programme.

Methods

This was a prospective multicentre (14 chronic haemodialysis centres, Lorraine Region) study encompassing 527 chronic haemodialysis patients followed from 2 January 2014 to 31 December 2015. Predialysis serum K (14 734) measurements, dialysis bath K concentrations and concomitant K binder prescriptions were collected with an electronic health record system.

Results

At baseline, 26.4%, 13.8% and 4.9% of patients were hyperkalaemic (i.e. K >5.1, 5.5 or 6 mmol/L, respectively) and 12.5%, 1.9% and 0.4% were hypokalaemic (i.e. K<4, 3.5 or 3 mmol/L, respectively). A total of 61% of patients were prescribed a K-binding resin [essentially sodium polystyrene sulfonate (SPS)], while 2 mmol/L and 3 mmol/L K concentration baths were used relatively equally. Over time, the proportion of patients being prescribed any K-binding agent increased up to 78%. The percentage of patients experiencing HK at any time was 73.8% (HK >5.1 mmol/L), 57.9% (HK >5.5 mmol/L) and 34.5% (HK >6 mmol/L). Only 6.3% of patients became normokalaemic within 3 months after an HK >5.5 mmol/L despite dynamic management of K baths and K binders (i.e. increased prescription of 2 mmol/L K baths and increased SPS doses).

Conclusions

HK was found to be highly prevalent and recurrent in this regional registry despite the widespread and dynamic prescription of low-K dialysis baths and K binders. More effective potassium mitigating strategies are eagerly warranted.

Hand grip strength measurement in haemodialysis patients: before or after the session?

Background

Hand grip strength (HGS) is a key measurement in the assessment of frailty phenotype in haemodialysis patients. However, the measurement is not very standardized, and notably, current data on the potential impact of a haemodialysis session on the results are both limited and controversial. In the present analysis, we compared HGS results before and after a haemodialysis session in 101 patients.

Methods

In the current observational study, HGS has been measured in adult haemodialysis patients on the same day, first before connection to the dialysis machine and then just after disconnection. At each timing, measurements were repeated three times with an interval of 5 s between measurements and the higher value was used for analysis.

Results

One hundred and one patients (64% men) with a median (interquartile range, 25th percentile; 75th percentile) age of 66 (46; 76) years were included. In the whole population, a significant decline in HGS was observed after dialysis, with an absolute median decline of − 4 (0; −6) kg and a relative median difference of −11 (0; −20)%. These differences were observed in both genders and were independent of the baseline HGS value.

Conclusions

Our results suggest that the timing (before or after the dialysis session) of hand grip assessment is clinically relevant and should be taken into account in clinical practice and also in epidemiological and clinical studies.

β-Thromboglobulin may not reflect platelet activation during haemodialysis with the HeprAN membrane

BACKGROUND

When blood passes through the extracorporeal circuit during haemodialysis (HD) undesirable effects including platelet degranulation and coagulation activation take place. β-thromboglobulin (β-TG) is a sensitive marker of platelet activation. The aim of this study was to investigate platelet degranulation and coagulation activation during HD with the heparin-coated dialysis membrane HeprAN.

METHODS

Four HD sessions were evaluated in each of 12 chronic HD patients. None of the patients used oral warfarin, other anticoagulants or antiplatelet drugs. In the first session the HeprAN membrane or a conventional polyflux membrane was used in a randomized manner and thereafter alternately in a cross-over design, and 50% of the conventional dalteparin dose was given at start of HD. Prothrombin fragment 1 + 2 (PF1 + 2), β-TG and anti-factor Xa activity were measured repeatedly.

RESULTS

No dialysis sessions were terminated early due to clotting of the extracorporeal system. Activation of intravascular coagulation as assessed by change in PF1 + 2 during 4 hours of HD was the same with the two membranes. β-TG concentration decreased significantly during 4 hours of HD with the HeprAN membrane but remained stable with the polyflux membrane.

CONCLUSION

There were no differences in clotting scores or coagulation activation with the two membranes. The decrease in β-TG during HD with the HeprAN membrane suggests β-TG to be an inferior marker of platelet degranulation when using a heparin-coated dialysis membrane. A possible mechanism for the decline in β-TG concentration may be adherence of this heparin-binding protein to the heparin-coated dialysis membrane.

Reduced Mortality in Maintenance Haemodialysis Patients on High versus Low Dialysate Magnesium: A Pilot Study

Background: Although low magnesium levels have been associated with an increased mortality in dialysis patients, they are kept low by routinely-used dialysates containing 0.50 mmol/L magnesium. Thus, we investigated the impact of a higher dialysate magnesium concentration on mortality. Methods: 25 patients on high dialysate magnesium (HDM) of 0.75 mmol/L were 1:2 matched to 50 patients on low dialysate magnesium (LDM) of 0.50 mmol/L and followed up for 3 years with regards to all-cause and cardiovascular mortality. Patients were matched according to age, gender, a modified version of the Charlson Comorbidity Index (CCI), and smoking status. Results: During the follow-up period, five patients died in the HDM and 18 patients in the LDM group. Patients in the HDM group had significantly higher ionized serum magnesium levels than matched controls (0.64 ± 0.12 mmol/L vs. 0.57 ± 0.10 mmol/L, p = 0.034). Log rank test showed no difference between treatment groups for all-cause mortality. After adjustment for age and CCI, Cox proportional hazards regression showed that HDM independently predicted a 65% risk reduction for all-cause mortality (hazard ratio 0.35, 95% confidence interval [CI]: 0.13, 0.97). Estimated 3-year probability of death from a cardiovascular event was 14.5% (95% CI: 7.9, 25.8) in the LDM group vs. 0% in the HDM group. Log rank test found a significant group difference for cardiovascular mortality (χ² = 4.15, p = 0.042). Conclusions: Our data suggests that there might be a beneficial effect of an increased dialysate magnesium on cardiovascular mortality in chronic dialysis patients.

Estimated dietary sodium intake in haemodialysis patients using food frequency questionnaires

BACKGROUND

In clinical practice, dietary sodium assessment requires reliable and rapid screening tools. We wished to evaluate the usefulness of food frequency questionnaires (FFQ) in estimating dietary sodium intakes in haemodialysis patients.

METHODS

We used the Derby Salt Questionnaire (DSQ), and Scored Sodium Questionnaire (SSQ) to estimate sodium intake. Body composition was determined by bioimpedance.

RESULTS

In total, 139 haemodialysis patients (95 men) completed the FFQs, with mean ± standard deviation age 67 ± 15 years. The mean FFQ scores were DSQ 3.5 ± 2.0 and SSQ 68.4 ± 24.5. Men had higher estimated dietary sodium intakes [DSQ median (range) 3.6 (0.6-10.1) versus female 2.2 (0.5-9.1), P = 0.007)]. Younger patients and those aged >75 years had the higher SSQ dietary sodium scores; 70.7 ± 27.8 and 76.8 ± 24.6 versus those aged 55-75 years, 61.8 ± 22.3, P = 0.04. Patients with greater estimated sodium intake had higher extracellular water (ECW) to intracellular water (ICW) ratios pre-dialysis [75.1 ±12.5 versus 67.7 ± 4.8, P < 0.001] and ECW excess pre-dialysis [1.8 (1.5-2.6) versus 1.3 (0.8-2.0) L, P < 0.05]. Mean arterial pressure (MAP) and inter-dialytic weight gains did not differ; however, the fall in MAP during dialysis was lower in the higher estimated dietary sodium group (0.9 ± 13.7% versus 6.5 ± 14.1%, P = 0.04).

CONCLUSIONS

Both questionnaires were acceptable to patients and identified higher estimated dietary sodium intake for men, those with greater ECW and, somewhat surprisingly, we found that older patients had a greater dietary sodium intake than expected.

Effect of ethnicity and socioeconomic status on vascular access provision and performance in an urban NHS hospital

BACKGROUND

The aim of this study was to examine the effect of ethnicity, socioeconomic group (SEG) and comorbidities on provision of vascular access for haemodialysis (HD).

METHODS

This was a retrospective review of two databases of HD sessions and access operations from 2003-11. Access modality of first HD session and details of transplanted patients were derived from the renal database. Follow-up was until 1 January 2015. Primary failure (PF) was defined as an arteriovenous fistula (AVF) used for fewer than six consecutive dialysis sessions. AVF survival was defined as being until the date the AVF was abandoned. Ethnicity was coded from hospital records. SEG was calculated from postcodes and 2011 census data from the Office of National Statistics. Comorbidities were calculated with the Charlson Comorbidity Index.

RESULTS

Five hundred incident patients started chronic HD in the study period. Mode of starting HD was not associated with ethnicity (P = 0.27) or SEG (P = 0.45). Patients from ethnic minorities were younger when starting dialysis (P < 0.0001). Some 928 AVF patients' first AVF operations were analysed: 68% Caucasian, 26% Asian and 6% Afro-Caribbean. Half were in the most deprived SEG and 11% in the least deprived SEG. PF did not differ by ethnicity (P = 0.29), SEG (P = 0.75) or comorbidities (P = 0.54). AVF survival was not different according to ethnicity (P = 0.13) or SEG (P = 0.87). AVF survival was better for patients with a low comorbidity score (P = 0.04). The distribution of transplant recipients by ethnic group and SEG was similar to the distributions of all HD starters.

CONCLUSION

Ethnicity and socioeconomic group had no effect on mode of starting HD, primary AVF failure rate or AVF survival. Ethnic minorities were younger at start of dialysis and at their first AVF operation.

Morbidity, mortality and quality of life in the ageing haemodialysis population: results from the ELDERLY study

Background

The physical–functional and social–emotional health as well as survival of the elderly (≥75 years of age) haemodialysis patient is commonly thought to be poor. In a prospective, multicentre, non-interventional, observational study, the morbidity, mortality and quality of life (QoL) in this patient group were examined and compared with a younger cohort.

Methods

In 92 German dialysis centres, 2507 prevalent patients 19–98 years of age on haemodialysis for a median of 19.2 months were included in a drug monitoring study of darbepoetin alfa. To examine outcome and QoL parameters, 24 months of follow-up data in the age cohorts <75 and ≥75 years were analysed. Treatment parameters, adverse and intercurrent events, hospitalizations, morbidity and mortality were assessed. QoL was evaluated by means of the 47-item Functional Assessment of Chronic Illness Therapy–Anaemia score (FACT-An, version 4).

Results

The 2-year mortality rate was 34.7% for the older cohort and 15.8% for the younger cohort. The mortality rate for the haemodialysed elderly patients was 6.2% higher in absolute value compared with the age-matched background population. A powerful predictor of survival was the baseline FACT-An score and a close correlation with the 20-item anaemia subscale (AnS) was demonstrated. While the social QoL in the elderly patients was more stable than in the younger cohort (leading to equivalent values at the end of the study period), a pronounced deterioration of physical and functional status was observed. The median number of all-cause hospital days per patient-year was 12.3 for the elderly cohort and 8.9 for the younger patient population. The overall 24-month hospitalization rate was only marginally higher in the elderly cohort (34.0 versus 33.3%).

Conclusions

In this observational study, the mortality rate of elderly haemodialysis patients was not exceedingly high compared with the age-matched background population. Furthermore, the hospitalization rate was only slightly higher compared with the younger age group and the median yearly hospitalization time trended lower compared with registry data. The social well-being of elderly haemodialysis patients showed a less pronounced decline over time and was equal to the score of the younger cohort at the end of the study period. The physical and functional status in the elderly patients was lower and showed a sharper decline over time. The baseline FACT-An score correlated closely with the 24-month survival probability.

High cut-off dialysis in chronic haemodialysis patients reduces serum procalcific activity

BACKGROUND

Vascular calcification is enhanced in chronic dialysis patients, possibly due to the insufficient removal of various intermediate molecular weight uraemic toxins such as interleukins with conventional membranes. In this study, we assessed the modulation of in vitro vascular calcification with the use of high cut-off (HCO) membranes in chronic dialysis patients.

METHODS

In a PERCI trial, 43 chronic dialysis patients were treated with conventional high-flux and HCO filters for 3 weeks in a randomized order following a 2-period crossover design. After each phase, serum predialysis samples were drawn. Calcifying human coronary vascular smooth muscle cells (VSMCs) were incubated with the patient's serum samples. Calcification was assessed with alkaline phosphatase (ALP) and alizarin red staining. In the clinical trial, HCO dialysis reduced the serum levels of the soluble tumour necrosis factor receptor (sTNFR) 1 and 2, vascular cell adhesion molecule 1 (VCAM-1) and soluble interleukin-2 receptor (sIL2R). We therefore investigated the in vitro effects of these mediators on vascular calcification.

RESULTS

VSMCs incubated with HCO dialysis serum showed a 26% reduction of ALP with HCO serum compared with high-flux serum. Alizarin was 43% lower after incubation with the HCO serum compared with the high-flux serum. While sIL2R and sTNFR 1 and 2 showed no effects on VSMC calcification, VCAM-1 caused a dose-dependent enhancement of calcification.

CONCLUSIONS

The use of HCO dialysis membranes in chronic dialysis patients reduces the procalcific effects of serum on VSMC in vitro. The mechanisms of the strong effect of HCO on in vitro calcification are not completely understood. One factor may be lower levels of VCAM-1 in HCO serum samples, since VCAM-1 was able to induce vascular calcification in our experiments. Neither sTNFR 1, sTNFR 2 nor sIL2R enhance vascular calcification in vitro. Regardless of the mechanisms, our results encourage further studies of highly permeable filters in chronic dialysis patients.

The outcome of the primary vascular access and its translation into prevalent access use rates in chronic haemodialysis patients

Background

The American Fistula First Breakthrough Initiative currently aims for a 66% arterio-venous fistula (AVF) rate, while in the UK, best practice tariffs target AVF and arterio-venous graft (AVG) rates of 85%. The present study aims to assess whether these goals can be achieved.

Methods

We conducted a retrospective cohort study on patients who initiated haemodialysis from 1995 to 2006. Outcomes were the final failure-free survival of the first permanent access and the type of second access created. Prevalent use rates for the access types were calculated on the 1st January of each year for the second half of the study period.

Results

Two hundred and eleven out of 246 patients (86%) received an AVF, 16 (6%) an AVG and 19 (8%) a permanent catheter (PC) as the first permanent access. Eighty-six (35%) patients had final failure of the primary access. One- and 3-year final failure-free survival rates were 73 and 65% for AVF compared with 40 and 20% for AVG and 62 and 0% for PC, respectively. In patients with primary AVF, female sex {hazard ratio (HR) 2.20 [confidence interval (CI) 1.29–3.73]} and vascular disease [HR 2.24 (CI 1.26–3.97)] were associated with a poorer outcome. A similar trend was observed for autoimmune disease [HR 2.14 (CI 0.99–4.65)]. As second accesses AVF, AVG and PC were created in 47% (n = 40), 38% (n = 33) and 15% (n = 13). The median prevalent use rate was 80.5% for AVF, 14% for AVG and 5.5% for PC.

Conclusions

The vascular access targets set by initiatives from the USA and UK are feasible in unselected haemodialysis patients. High primary AVF rates, the superior survival rates of AVFs even in patient groups at higher risk of access failure and the high rate of creation of secondary AVFs contributed to these promising results.