Beyond sarcopenia: frailty in chronic haemodialysis patients.

Background: Frailty, characterized by vulnerability, reduced reserves and increased susceptibility to severe events, is a significant concern in chronic haemodialysis (HD) patients. Sarcopenia, corresponding to the progressive loss of muscle mass and strength, may contribute to frailty by reducing functional capacity, mobility and autonomy. However, consensus lacks on the optimal bedside frailty index for chronic HD patients. This study investigated the influence of frailty on chronic HD patient survival and explored the associated factors. Methods: A total of 135 patients were enrolled from January to April 2019 and then followed up prospectively until April 2022. At inclusion, frailty was assessed by the Timed Up and Go (TUG) and Short Physical Performance Battery (SPPB) tests including gait speed, standing balance and lower limb muscle strength. Results: From a total of 114 prevalent chronic HD patients (66% men, age 67.6 ± 15.1 years), 30 died during the follow-up period of 23.7 months (range 16.8-34.3). Deceased patients were older, had more comorbidities and a higher sarcopenia prevalence (P < .05). The TUG and SPPB test scores were significantly reduced in patients who had died [SPPB total score: 7.2 ± 3.3 versus 9.4 ± 2.5; TUG time 8.7 ± 5.8 versus 13.8 ± 10.5 (P < .05)]. Multivariate analysis showed that a higher SPPB score (total value >9) was associated with a lower mortality risk [hazard ratio 0.83 (95% confidence interval 0.74-0.92); P < .03). Each component of the SPPB test was also associated with mortality in univariate analysis, but only the SPPB balance test remained protective against mortality in multivariate analysis. Older age, lower handgrip strength and lower protein catabolic rate were associated with SPPB total scores <9, SPPB balance score and TUG time >10 s. Conclusions: Screening for frailty is crucial in chronic HD patients, and incorporating SPPB, especially the balance test, provides valuable insights. Diminished muscle strength and inadequate protein intake negatively influence the SPPB score and balance in chronic HD patients. Effective identification and management of frailty can therefore improve outcomes. CLINICAL TRIAL REGISTRATION ClinicalTrialsgov: NCT03845452.

Association of calciprotein particles with serum phosphorus among patients undergoing conventional and extended-hours haemodialysis.

Background and hypothesis: Extended-hours haemodialysis (HD) is associated with better clinical outcomes than conventional HD. We investigated whether extended-hours HD and conventional HD have varying effects on blood levels of calciprotein particles (CPPs) and phosphorus, which have been identified as major pathogenic molecules for vascular calcification. Methods: Patients who underwent conventional or extended in-centre daytime HD between January and March 2020 were included. Plasma CPP levels, representing only secondary CPPs (CPP-II), were measured in pre-dialysis samples. Linear and non-linear associations between CPPs and serum phosphorus levels were examined across dialysis modalities. Results: A total of 382 participants (185 undergoing extended-hours HD and 197 undergoing conventional HD) were included in the analysis. The median age of participants was 71 years, 65% of the patients were men and the mean phosphorus level was 5.4 mg/dl. Plasma CPP (CPP-II) levels were lower in the extended-hours HD group than in the conventional HD group [40 018 (arbitrary units) AU versus 75 728 AU; P < .01]. Multivariable linear regression analysis showed that extended-hours HD was associated with lower natural logarithmic plasma CPP (CPP-II) levels: -0.64 (95% confidence interval -0.74 to -0.55). A restricted cubic spline function indicated that extended-hours HD was associated with lower plasma CPP (CPP-II) levels across levels of serum phosphorus, with significant differences observed between groups, especially in hyperphosphataemic conditions (P for interaction <.01). Conclusions: The extended-hours HD group had lower CPP levels than the conventional HD group despite no significant differences in serum phosphorus levels, which may contribute to better clinical outcomes in patients on extended-hours HD.

Doppler ultrasound surveillance of recently formed haemodialysis arteriovenous fistula: the SONAR observational cohort study.

Background: Arteriovenous fistulas are considered the best option for haemodialysis provision, but as many as 30% fail to mature or suffer early failure. Objective: To assess the feasibility of performing a randomised controlled trial that examines whether, by informing early and effective salvage intervention of fistulas that would otherwise fail, Doppler ultrasound surveillance of developing arteriovenous fistulas improves longer-term arteriovenous fistula patency. Design: A prospective multicentre observational cohort study (the 'SONAR' study). Setting: Seventeen haemodialysis centres in the UK. Participants: Consenting adults with end-stage renal disease who were scheduled to have an arteriovenous fistula created. Intervention: Participants underwent Doppler ultrasound surveillance of their arteriovenous fistulas at 2, 4, 6 and 10 weeks after creation, with clinical teams blinded to the ultrasound surveillance findings. Main outcome measures: Fistula maturation at week 10 defined according to ultrasound surveillance parameters of representative venous diameter and blood flow (wrist arteriovenous fistulas: ≥ 4 mm and > 400 ml/minute; elbow arteriovenous fistulas: ≥ 5 mm and > 500 ml/minute). Mixed multivariable logistic regression modelling of the early ultrasound scan data was used to predict arteriovenous fistula non-maturation by 10 weeks and fistula failure at 6 months. Results: A total of 333 arteriovenous fistulas were created during the study window (47.7% wrist, 52.3% elbow). By 2 weeks, 37 (11.1%) arteriovenous fistulas had failed (thrombosed), but by 10 weeks, 219 of 333 (65.8%) of created arteriovenous fistulas had reached maturity (60.4% wrist, 67.2% elbow). Persistently lower flow rates and venous diameters were observed in those fistulas that did not mature. Models for arteriovenous fistulas' non-maturation could be optimally constructed using the week 4 scan data, with fistula venous diameter and flow rate the most significant variables in explaining wrist fistula maturity failure (positive predictive value 60.6%, 95% confidence interval 43.9% to 77.3%), whereas resistance index and flow rate were most significant for elbow arteriovenous fistulas (positive predictive value 66.7%, 95% confidence interval 48.9% to 84.4%). In contrast to non-maturation, both models predicted fistula maturation much more reliably [negative predictive values of 95.4% (95% confidence interval 91.0% to 99.8%) and 95.6% (95% confidence interval 91.8% to 99.4%) for wrist and elbow, respectively]. Additional follow-up and modelling on a subset (n = 192) of the original SONAR cohort (the SONAR-12M study) revealed the rates of primary, assisted primary and secondary patency arteriovenous fistulas at 6 months were 76.5, 80.7 and 83.3, respectively. Fistula vein size, flow rate and resistance index could identify primary patency failure at 6 months, with similar predictive power as for 10-week arteriovenous fistula maturity failure, but with wide confidence intervals for wrist (positive predictive value 72.7%, 95% confidence interval 46.4% to 99.0%) and elbow (positive predictive value 57.1%, 95% confidence interval 20.5% to 93.8%). These models, moreover, performed poorly at identifying assisted primary and secondary patency failure, likely because a subset of those arteriovenous fistulas identified on ultrasound surveillance as at risk underwent subsequent successful salvage intervention without recourse to early ultrasound data. Conclusions: Although early ultrasound can predict fistula maturation and longer-term patency very effectively, it was only moderately good at identifying those fistulas likely to remain immature or to fail within 6 months. Allied to the better- than-expected fistula patency rates achieved (that are further improved by successful salvage), we estimate that a randomised controlled trial comparing early ultrasound-guided intervention against standard care would require at least 1300 fistulas and would achieve only minimal patient benefit. Trial Registration: This trial is registered as ISRCTN36033877 and ISRCTN17399438. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR135572) and is published in full in Health Technology Assessment; Vol. 28, No. 24. See the NIHR Funding and Awards website for further award information.

For people with advanced kidney disease, haemodialysis is best provided by an 'arteriovenous fistula', which is created surgically by joining a vein onto an artery at the wrist or elbow. However, these take about 2 months to develop fully ('mature'), and as many as 3 out of 10 fail to do so. We asked whether we could use early ultrasound scanning of the fistula to identify those that are unlikely to mature. This would allow us to decide whether it would be practical to run a large, randomised trial to find out if using early ultrasound allows us to 'rescue' fistulas that would otherwise fail. We invited adults to undergo serial ultrasound scanning of their fistula in the first few weeks after it was created. We then analysed whether we could use the data from the early scans to identify those fistulas that were not going to mature by week 10. Of the 333 fistulas that were created, about two-thirds reached maturity by week 10. We found that an ultrasound scan 4 weeks after fistula creation could reliably identify those fistulas that were going to mature. However, of those fistulas predicted to fail, about one-third did eventually mature without further intervention, and even without knowing what the early scans showed, another third were successfully rescued by surgery or X-ray-guided treatment at a later stage. Performing an early ultrasound scan on a fistula can provide reassurance that it will mature and deliver trouble-free dialysis. However, because scans are poor at identifying fistulas that are unlikely to mature, we would not recommend their use to justify early surgery or X-ray-guided treatment in the expectation that this will improve outcomes.

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.

Time-averaged concentration estimation of uraemic toxins with different removal kinetics: a novel approach based on intradialytic spent dialysate measurements.

Background: Kt/Vurea is the most used marker to estimate dialysis adequacy; however, it does not reflect the removal of many other uraemic toxins, and a new approach is needed. We have assessed the feasibility of estimating intradialytic serum time-averaged concentration (TAC) of various uraemic toxins from their spent dialysate concentrations that can be estimated non-invasively online with optical methods. Methods: Serum and spent dialysate levels and total removed solute (TRS) of urea, uric acid (UA), indoxyl sulphate (IS) and ß2-microglobulin (ß2M) were evaluated with laboratory methods during 312 haemodialysis sessions in 78 patients with four different dialysis treatment settings. TAC was calculated from serum concentrations and evaluated from TRS and logarithmic mean concentrations of spent dialysate (MlnD). Results: Mean (± standard deviation) intradialytic serum TAC values of urea, UA, ß2M and IS were 10.4 ± 3.8 mmol/L, 191.6 ± 48.1 µmol/L, 13.3 ± 4.3 mg/L and 82.9 ± 43.3 µmol/L, respectively. These serum TAC values were similar and highly correlated with those estimated from TRS [10.5 ± 3.6 mmol/L (R 2 = 0.92), 191.5 ± 42.8 µmol/L (R 2 = 0.79), 13.0 ± 3.2 mg/L (R 2 = 0.59) and 82.7 ± 40.0 µmol/L (R 2 = 0.85)] and from MlnD [10.7 ± 3.7 mmol/L (R 2 = 0.92), 191.6 ± 43.8 µmol/L (R 2 = 0.80), 12.9 ± 3.2 mg/L (R 2 = 0.63) and 82.2 ± 38.6 µmol/L (R 2 = 0.84)], respectively. Conclusions: Intradialytic serum TAC of different uraemic toxins can be estimated non-invasively from their concentration in spent dialysate. This sets the stage for TAC estimation from online optical monitoring of spent dialysate concentrations of diverse solutes and for further optimization of estimation models for each uraemic toxin.

Effect of the phosphate binder sucroferric oxyhydroxide in dialysis patients on endogenous calciprotein particles, inflammation, and vascular cells.

BACKGROUND: Calciprotein particles (CPPs), colloidal mineral-protein nanoparticles, have emerged as potential mediators of phosphate toxicity in dialysis patients, with putative links to vascular calcification, endothelial dysfunction and inflammation. We hypothesized that phosphate binder therapy with sucroferric oxyhydroxide (SO) would reduce endogenous CPP levels and attenuate pro-calcific and pro-inflammatory effects of patient serum towards human vascular cells in vitro. METHODS: This secondary analysis of a randomised controlled crossover study compared the effect of 2-week phosphate binder washout with high-dose (2000 mg/day) and low-dose (250 mg/day) SO therapy in 28 haemodialysis patients on serum CPP levels, inflammatory cytokine/chemokine arrays and human aortic smooth muscle cell (HASMC) and coronary artery endothelial cell (HCAEC) bioassays. RESULTS: In our cohort (75% male, 62 ± 12 years) high-dose SO reduced primary (amorphous) and secondary (crystalline) CPP levels {-62% [95% confidence interval (CI) -76 to -44], P < .0001 and -38% [-62 to -0.14], P < .001, respectively} compared with washout. Nine of 14 plasma cytokines/chemokines significantly decreased with high-dose SO, with consistent reductions in interleukin-6 (IL-6) and IL-8. Exposure of HASMC and HCAEC cultures to serum of SO-treated patients reduced calcification and markers of activation (IL-6, IL-8 and vascular cell adhesion protein 1) compared with washout. Serum-induced HASMC calcification and HCAEC activation was ameliorated by removal of the CPP-containing fraction from patient sera. Effects of CPP removal were confirmed in an independent cohort of chronic kidney disease patients. CONCLUSIONS: High-dose SO reduced endogenous CPP formation in dialysis patients and yielded serum with attenuated pro-calcific and inflammatory effects in vitro.

Impact of the COVID pandemic on vascular access creation for haemodialysis in 16 Spanish haemodialysis centres.

Background: The coronavirus disease (COVID) pandemic has resulted in a major disruption in healthcare that has affected several medical and surgical specialties. European and American Vascular Societies have proposed deferring the creation of an elective vascular access (VA) [autologous or prosthetic arteriovenous fistula (AVF) or arteriovenous graft (AVG)] in incident patients on haemodialysis (HD) in the era of the COVID pandemic. The aim of this study is to examine the impact of the COVID pandemic on VA creation and the central venous catheter (CVC)-related hospitalizations and complications in HD patients dialyzed in 16 Spanish HD units of three different regions. Methods: We compared retrospectively two periods of time: the pre-COVID (1 January 2019-11 March 2020) and the COVID era (12 March 2020-30 June 2021) in all HD patients (prevalent and incident) dialyzed in our 16 HD centres. The variables analysed were type of VA (CVC, AVF and AVG) created, percentage of CVC in incident and prevalent HD patients, CVC-related hospitalizations and complications (infection, extrusion, disfunction, catheter removal) and percentage of CVC HD sessions that did not reach the goal of Kt (>45) as a marker of HD adequacy. Results: A total of 1791 VAs for HD were created and 905 patients started HD during the study period. Patients who underwent vascular access surgery during the COVID period compared with pre-COVID period were significantly younger, with a significant decrease in surgical activity to create AVFs and AVGs in older HD patients (>75 and >85 years of age). There was a significant increase in CVC placement (from 59.7% to 69.5%; P < 0.001) from the pre-COVID to the COVID period. During the COVID pandemic, a significantly higher number of patients started HD through a CVC (80.3% versus 69.1%; P < 0.001). The percentage of CVC in prevalent HD patients has not decreased in the 19 months since the start of the pandemic [414 CVC/1058 prevalent patients (39.4%)]. No significant changes were detected in CVC-related hospitalizations between the pre-COVID and COVID periods. In the COVID period, a significant increase in catheter replacement and the percentage of HD session that did not reach the HD dose objective (Kt > 45) was observed. Conclusions: COVID has presented a public health system crisis that has influenced VA for HD, with an increase in CVCs relative to AVFs. A decrease in HD sessions that did not reach the HD dose objective was observed in the COVID period compared with a pre-COVID period.

Surgical versus endovascular intervention for vascular access thrombosis: a nationwide observational cohort study.

BACKGROUND: There is no consensus whether an arteriovenous (AV) access thrombosis is best treated by surgical or endovascular intervention. We compared the influence of surgical versus endovascular intervention for AV access thrombosis on access survival using real-life data from a national access registry. METHODS: We included patients from the Swedish Renal Access Registry (SRR-Access) with a working AV access undergoing surgical or endovascular intervention for their first thrombosis between 2008 and 2020. The primary outcome was the risk of access abandonment (secondary patency at 30, 60, 90 and 365 days). Secondary outcomes were time to next intervention and 30-day mortality. Access characteristics were obtained from the SRR-Access and patient characteristics were collected from the Swedish Renal Registry. Outcomes were assessed with multivariable logistic regression and Cox proportional hazards regression models adjusted for demographics, clinical and access-related variables. RESULTS: A total of 904 patients with AV access thrombosis (54% arteriovenous fistula, 35% upper arm access) were included, with a mean age of 62 years, 60% were women, 75% had hypertension and 33% had diabetes. Secondary patency was superior after endovascular intervention versus surgical (85% versus 77% at 30 days and 76% versus 69% at 90 days). The adjusted odds of access abandonment within 90 days and 1 year were higher in the surgical thrombectomy group {odds ratio (OR) 1.44 [95% confidence interval (CI) 1.05-1.97] and OR 1.25 (0.94-1.66), respectively}. Results were consistent in the long-term analysis. There was no significant difference in time to next intervention or mortality, and results were consistent within subgroups. CONCLUSIONS: Endovascular intervention was associated with a small short- and long-term benefit as compared with open surgery in haemodialysis patients with AV access thrombosis.

Work status and work ability of patients receiving kidney replacement therapy: results from a European survey.

BACKGROUND: Employment is important for the quality of life and financial security of patients of working age receiving kidney replacement therapy (KRT). We aimed to examine self-reported work status and general, physical and mental work ability and to determine associations between demographic, disease-related, work-related and macroeconomic factors and employment. . METHODS: Europeans from 37 countries, ages 19-65 years, treated with dialysis or kidney transplantation, filled out the web-based or paper-based cross-sectional EDITH kidney patient survey between November 2017 and January 2019. We performed descriptive analyses and multivariable generalized logistic mixed models. RESULTS: Of the 3544 patients, 36.5% were employed and working [25.8% of dialysis patients, 53.9% of kidney transplant recipients (KTRs)]. The mean general work ability was 5.5 out of 10 (dialysis: 4.8, KTRs: 6.5). Non-working patients (all: 4.1, dialysis: 3.9, KTRs: 4.7) scored lower than working patients (all: 7.7, dialysis 7.3, KTRs: 8.0). Working dialysis patients scored lower on physical and mental work ability (7.1 and 8.1) than working KTRs (8.0 and 8.4; P < 0.001). Impaired physical work ability (42.7%) was more prevalent than impaired mental work ability (26.7%). Male sex, age 40-49 years, higher education, home dialysis or kidney transplantation as current treatment, treatment history including kidney transplantation, absence of diabetes mellitus, better general work ability and higher country gross domestic product were positively associated with employment (P < 0.05). CONCLUSIONS: Low employment rates and impaired work ability were prevalent among European patients receiving KRT. Demographic, disease-related, work-related and macro-economic factors were associated with employment.

Smoking and risk of fractures requiring hospitalization in haemodialysis patients: a nationwide cohort study in Japan.

BACKGROUND: Smoking is a well-established lifestyle risk factor for fractures in the general population, but evidence specific to haemodialysis populations is lacking. This nationwide cohort study used data from the Japanese Society for Dialysis Therapy Renal Data Registry to examine the association between smoking status and fractures. METHODS: A total of 154 077 patients (64.2% men; mean age 68 years) aged ≥20 years undergoing maintenance haemodialysis thrice weekly at the end of 2016 were followed for 1 year. Among these, 19 004 (12.3%) patients were current smokers. Standardized incidence rate ratios of hospitalization due to any fracture were calculated and analysed by multivariable logistic regression analysis, controlling for potential confounders. Propensity score (PS) matching and subgroup analyses were also performed as sensitivity analyses. RESULTS: During the 1-year follow-up period, 3337 fractures requiring hospitalization (1201 hip, 479 vertebral and 1657 other fractures) occurred in 3291 patients. The age- and sex-standardized incidence ratio for current smokers was 1.24 (95% confidence interval 1.12-1.39) relative to non-smokers. Standardized incidence ratios were similar after stratification by age group and sex. Multivariable logistic regression analysis revealed a 1.25-fold higher risk of any fracture requiring hospitalization (95% confidence interval 1.10-1.42) in current smokers relative to non-smokers in a fully adjusted model. PS matching showed similar results (odds ratio 1.25; 95% confidence interval 1.05-1.48). Subgroup analyses for baseline covariates revealed no significant interactions. CONCLUSIONS: Smoking is a significant risk factor for any fracture requiring hospitalization in haemodialysis patients.

Patient-reported factors influencing the choice of their kidney replacement treatment modality.

BACKGROUND: Access to various kidney replacement therapy (KRT) modalities for patients with end-stage kidney disease differs substantially within Europe. METHODS: European adults on KRT filled out an online or paper-based survey about factors influencing and experiences with modality choice (e.g. information provision, decision-making and reasons for choice) between November 2017 and January 2019. We compared countries with low, middle and high gross domestic product (GDP). RESULTS: In total, 7820 patients [mean age 59 years, 56% male, 63% on centre haemodialysis (CHD)] from 38 countries participated. Twenty-five percent had received no information on the different modalities, and only 23% received information >12 months before KRT initiation. Patients were not informed about home haemodialysis (HHD) (42%) and comprehensive conservative management (33%). Besides nephrologists, nurses more frequently provided information in high-GDP countries, whereas physicians other than nephrologists did so in low-GDP countries. Patients from low-GDP countries reported later information provision, less information about other modalities than CHD and lower satisfaction with information. The majority of modality decisions were made involving both patient and nephrologist. Patients reported subjective (e.g. quality of life and fears) and objective reasons (e.g. costs and availability of treatments) for modality choice. Patients had good experiences with all modalities, but experiences were better for HHD and kidney transplantation and in middle- and high-GDP countries. CONCLUSION: Our results suggest European differences in patient-reported factors influencing KRT modality choice, possibly caused by disparities in availability of KRT modalities, different healthcare systems and varying patient preferences. Availability of home dialysis and kidney transplantation should be optimized.

[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: SARS­CoV­2-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 SARS­CoV­2-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.

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™.

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.

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.

Chronic haemodialysis in infants and children less than 15 kg.

BACKGROUND: Peritoneal dialysis (PD) is the most commonly used kidney replacement therapy in infants and young children with chronic kidney disease (CKD) stage 5. Chronic haemodialysis (cHD) is the alternative treatment when PD is not possible for technical reasons; however, the difficulties that may be encountered are challenging and require clinicians with specialist training and experience. This study aims to describe the clinical history, complications and outcomes in children < 15 kg on cHD. METHODS: A retrospective, descriptive study of the clinical records of patients weighing < 15 kg on cHD for more than 3 months. The reasons for CKD stage 5, age at start of treatment, duration of haemodialysis, anthropometric and metabolic variables, as well as vascular access, complications and clinical outcome were recorded. RESULTS: Fifteen patients were included between 2006 and 2018 with a median age at start of cHD of 30 (interquartile range (IQR) 13, 39) months and median duration of 15 (IQR 7.5, 25.3) months. Five patients were younger than 2 years. The median weight at start of treatment was 11.2 (IQR 6.4, 12.8) kg. Forty-five tunneled catheters with a median survival of 106 days were used. The main cause of loss of vascular access was obstruction or displacement dysfunction (39%). The catheter-associated infection rate was 0.76 per 1000 catheter days. Ten patients received a successful kidney transplant, 4 were transferred to PD and one died from complications during abdominal surgery. CONCLUSIONS: cHD can be successfully performed in children < 15 kg by addressing specific clinical and technical issues.

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.

[Epidemiologic and clinical profile, 90 days survival of incident end stage renal patient in haemodialysis during SARS-CoV2 pandemic: Experience of the General Hospital of Douala]. / Profil épidémiologique et clinique, et survie à 90 jours des patients incidents en hémodialyse chronique au cours de la pandémie à SARS-CoV2 au Cameroun : expérience de l'hôpital général de Douala.

BACKGROUND: The effect of COVID-19 pandemic on end stage renal disease patient who should initiated dialysis are limited in Sub-Saharan Africa is unknown. We sought to describe the epidemiologic and clinical profile of newly admitted patient in chronic haemodialysis during the COVID-19 pandemic in Cameroon and evaluate their survival between 90days of dialysis initiation. MATERIAL AND METHOD: We conducted a cohort study of 6months from April to October 2020. End stage renal disease patients newly admitted in the haemodialysis facility of the General Hospital of Douala were included. Patients with confirmed or suspected COVID-19 were identified. Socio-demographic, clinical and biological data at dialysis initiation as well as mortality between the 90days of dialysis initiation were registered. RESULTS: A total of 57 incident patients were recorded from April to October 2020 with a monthly mean of 9.5 patients. The mean age was 46.95±13.12years. Twenty-four COVID-19 were identified with a frequency of 49% among emergency admission. Pulmonary œdema (79.2% vs. 42.4%; P=0.006) and uremic encephalopathy (83.4% vs. 53.6%; P=0.022) were more common in COVID-19. The overall survival at 90days was 48% with a tendency to poor survival among COVID-19 and patients with low socioeconomic level. In Cox regression, low socioeconomic level increase the risk of instant death by 3.08. CONCLUSION: SARS-CoV2 seem to increase nephrology emergency and poor survival in haemodialysis at 90days.