Detection and Scoring of Extracorporeal Circuit Clotting During Hemodialysis.

Maintaining patency of the extracorporeal hemodialysis (HD) circuit is a prerequisite to perform HD. Unfractionated heparin and low-molecular-weight heparins are the most used anticoagulants in maintenance HD, but their administration comes with a major trade-off of bleeding complications. This narrative review article discusses technical factors impacting on HD circuit patency, such as tubings, dialyzer membranes, priming practices, and treatment settings. Strategies for monitoring extracorporeal circuit clotting during and after treatment are also reviewed, as these are essential tools for optimizing anticoagulation.

Avoiding Systemic Heparinization During Hemodialysis: How the Dialysis Setup Might Help.

Heparin is the most widely used anticoagulant for maintaining patency of the extracorporeal blood circuit during intermittent hemodialysis. Inadvertently, this leads to systemic heparinization of the patient. Repeated intermittent heparinization during hemodialysis has been associated with increased bleeding risks and metabolic and immunologic effects. Alternative strategies for minimizing systemic anticoagulation encompass dilution methods, regional citrate anticoagulation, priming of the extracorporeal circuit, and modifications to dialyzer membranes and dialysate composition. The effectiveness of these alternatives in maintaining patency of the extracorporeal circuit varies substantially. Although most studies have focused on particular changes in the hemodialysis setup, several combined interventions for adapting the hemodialysis setup are now being studied. This narrative review aims to present an overview of the current landscape of hemodialysis setup strategies aimed at limiting or avoiding systemic anticoagulation during treatment. Additionally, this review intends to shed light on the underlying pathophysiological mechanisms that contribute to variations observed in reported outcomes.

Risk for excessive anticoagulation during hemodialysis is associated with type of vascular access and bedside coagulation testing: Results of a cross-sectional study.

Background: Recommendations and practice patterns for heparin dosing during hemodialysis show substantial heterogeneity and are scantly supported by evidence. This study assessed the variability in unfractionated heparin (UFH) dosing during hemodialysis and its clinical and biological anticoagulatory effects, and identified explanatory factors of heparin dosing. Methods: Cross-sectional study assessing UFH dosing, coagulation tests - activated partial thromboplastin time (aPTT) and activated clotting time (ACT) before dialysis start, 1 h after start and at treatment end (4 h) - and measurement of residual blood compartment volume of used dialyzers. Results: 101 patients, 58% male, with a median dialysis vintage of 33 (6-71) months received hemodialysis using a total UFH dose of 9,306 ± 4,079 (range 3,000-23,050) IU/session. Use of a dialysis catheter (n = 56, 55%) was associated with a 1.4 times higher UFH dose (p < 0.001) irrespective of prior access function. aPTT increased significantly more than ACT both 1 h and 4 h after dialysis start, independent of the dialysis access used. 53% of patients with catheter access and ACT ratio < 1.5, 1 h after dialysis start had simultaneous aPTT ratios > 2.5. Similar findings were present at 1 h for patients with AVF/AVG and at dialysis end for catheter use. No clinically significant clotting of the extracorporeal circuit was noted during the studied sessions. Dialyzer's blood compartment volume was reduced with a median of 9% (6-20%) without significant effect of UFH dose, aPTT or ACT measurements and vascular access type. Conclusion: UFH dose adaptations based on ACT measurements frequently result in excessive anticoagulation according to aPTT results. Higher doses of UFH are used in patients with hemodialysis catheters without evidence that this reduces dialyzer clotting.

Dialyzer Performance During Hemodialysis Without Systemic Anticoagulation Using a Heparin-Grafted Dialyzer Combined With a Citrate-Enriched Dialysate: Results of the Randomized Crossover Noninferiority EvoCit Study.

RATIONALE & OBJECTIVE: The EvoCit study was designed to evaluate performance of a heparin-grafted dialyzer during hemodialysis with and without systemic anticoagulation. STUDY DESIGN: Randomized, crossover, noninferiority trial. Noninferiority was defined as a difference of≤10% for the primary outcome. SETTING & PARTICIPANTS: Single hemodialysis center; 26 prevalent patients treated with 617 hemodialysis sessions. INTERVENTIONS: Hemodialysis using a heparin-grafted dialyzer combined with a 1.0mmol/L citrate-enriched dialysate ("EvoCit") without systemic anticoagulation compared with hemodialysis performed with a heparin-grafted dialyzer with systemic heparin ("EvoHep"). Patients were randomly allocated to a first period of 4 weeks and crossed over to the alternative strategy for a second period of 4 weeks. OUTCOMES: The primary end point was the difference in Kt/Vurea between EvoCit and EvoHep. Secondary end points were urea reduction ratio, middle molecule removal, treatment time, thrombin generation, and reduction in dialyzer blood compartment volume. RESULTS: The estimated difference in Kt/Vurea between EvoCit and EvoHep was-0.03 (95% CI, -0.06 to-0.007), establishing noninferiority with mean Kt/Vurea of 1.47±0.05 (SE) for EvoCit and 1.50±0.05 for EvoHep. Noninferiority was also established for reduction ratios of urea and ß2-microglobulin. Premature discontinuation of dialysis was required for 4.2% of sessions among 6 patients during EvoCit and no sessions during EvoHep. Effective treatment time was 236±5 minutes for EvoCit and 238±1 minutes for EvoHep. Thrombin generation was increased and there was greater reduction in dialyzer blood compartment volume after treatments with EvoCit compared with EvoHep. LIMITATIONS: The effects of avoiding systemic anticoagulation on clinical outcomes were not evaluated. CONCLUSIONS: EvoCit is noninferior to EvoHep with respect to solute clearance but results in a greater number of shortened treatments, more membrane clotting, and greater thrombin generation TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT03887468.

Assisted peritoneal dialysis across Europe: Practice variation and factors associated with availability.

BACKGROUND: In Europe, the number of elderly end-stage kidney disease patients is increasing. Few of those patients receive peritoneal dialysis (PD), as many cannot perform PD autonomously. Assisted PD programmes are available in most European countries, but the percentage of patients receiving assisted PD varies considerably. Hence, we assessed which factors are associated with the availability of an assisted PD programme at a centre level and whether the availability of this programme is associated with proportion of home dialysis patients. METHODS: An online survey was sent to healthcare professionals of European nephrology units. After selecting one respondent per centre, the associations were explored by χ2 tests and (ordinal) logistic regression. RESULTS: In total, 609 respondents completed the survey. Subsequently, 288 respondents from individual centres were identified; 58% worked in a centre with an assisted PD programme. Factors associated with availability of an assisted PD programme were Western European and Scandinavian countries (OR: 5.73; 95% CI: 3.07-10.68), non-academic centres (OR: 2.01; 95% CI: 1.09-3.72) and centres with a dedicated team for education (OR: 2.87; 95% CI: 1.35-6.11). Most Eastern & Central European respondents reported that the proportion of incident and prevalent home dialysis patients was <10% (72% and 63%), while 27% of Scandinavian respondents reported a proportion of >30% for both incident and prevalent home dialysis patients. Availability of an assisted PD programme was associated with a higher incidence (cumulative OR: 1.91; 95% CI: 1.21-3.01) and prevalence (cumulative OR: 2.81; 95% CI: 1.76-4.47) of patients on home dialysis. CONCLUSIONS: Assisted PD was more commonly offered among non-academic centres with a dedicated team for education across Europe, especially among Western European and Scandinavian countries where higher incidence and prevalence of home dialysis patients was reported.

Barriers and opportunities to increase PD incidence and prevalence: Lessons from a European Survey.

INTRODUCTION: Peritoneal dialysis (PD) remains underutilised and unplanned start of dialysis further diminishes the likelihood of patients starting on PD, although outcomes are equal to haemodialysis (HD). METHODS: A survey was sent to members of EuroPD and regional societies presenting a case vignette of a 48-year-old woman not previously known to the nephrology department and who arrives at the emergency department with established end-stage kidney disease (unplanned start), asking which dialysis modality would most likely be chosen at their respective centre. We assessed associations between the modality choices for this case vignette and centre characteristics and PD-related practices. RESULTS: Of 575 respondents, 32.8%, 32.2% and 35.0% indicated they would start unplanned PD, unplanned HD or unplanned HD with intention to educate patient on PD later, respectively. Likelihood for unplanned start of PD was only associated with quality of structure of the pre-dialysis program. Structure of pre-dialysis education program, PD program in general, likelihood to provide education on PD to unplanned starters, good collaboration with the PD access team and taking initiatives to enhance home-based therapies increased the likelihood unplanned patients would end up on PD. CONCLUSIONS: Well-structured pre-dialysis education on PD as a modality, good connections to dedicated PD catheter placement teams and additional initiatives to enhance home-based therapies are key to grow PD programs. Centres motivated to grow their PD programs seem to find solutions to do so.

Varying Presentations of Multisystem Inflammatory Syndrome Temporarily Associated with COVID-19.

Background. A novel coronavirus identified in 2019 leads to a pandemic of severe acute respiratory distress syndrome with important morbidity and mortality. Initially, children seemed minimally affected, but there were reports of cases similar to (atypical) Kawasaki disease or toxic shock syndrome, and evidence emerges about a complication named paediatric inflammatory multisystem syndrome temporarily associated with SARS-CoV-2 (PIMS-TS) or multisystem inflammatory syndrome in children (MIS-C). Case Presentations. Two cases were compared and discussed demonstrating varying presentations, management, and evolution of MIS-C. These cases are presented to increase awareness and familiarity among paediatricians and emergency physicians with the different clinical manifestations of this syndrome. Discussion. MIS-C may occur with possible diverse clinical presentations. Early recognition and treatment are paramount for a beneficial outcome.

Hemodialysis Does Not Induce Detectable Activation of the Contact System of Coagulation.

INTRODUCTION: Systemic anticoagulation is administered during hemodialysis to prevent clotting of the extracorporeal circuit. The role of contact system activation in thrombin generation during hemodialysis using current era dialyzer membranes is unknown. METHODS: We performed a single-center randomized crossover study. Ten patients treated with hemodialysis underwent 3 standardized hemodialysis sessions. For every patient, each session was performed with a different type of dialyzer membrane (polyphenylene [PP], polymethylmetacrylate [PMMA], polyethylenimine-coated polyacrylonitrile [AN69ST]). Blood samples were collected before and 5, 15, 30, 90, and 240 minutes after blood pump start to evaluate coagulation activation (thrombin-antithrombin complex [TAT], prothrombin fragment 1+2 [PF1+2], activated factor XII [FXIIa], kallikrein, activated factor XI [FXIa]). Plasma of healthy volunteers (n = 20) was used as a reference. RESULTS: Baseline TAT and PF1+2 levels were higher in hemodialysis patients compared to healthy controls (median [interquartile range] for TAT: 3.3 [2.9-4.2] vs. 2.4 [2.3-2.5] µg/l [P = 0.0002] and for PF1+2: 647 [478-737] vs. 138 [125-254] pmol/l [P < 0.0002]). Despite the use of systemic anticoagulation, TAT further increased during treatment, with the increase starting after 30 minutes (median TAT at t240: 9.0 µg/l (PP), 5.5 µg/l (PMMA), and 7.2 µg/l (AN69ST), all P < 0.05 vs. baseline). Contact system markers FXIIa and kallikrein did not differ significantly between dialysis patients and healthy controls, whereas baseline FXIa levels were significantly lower in dialysis patients compared to healthy controls (P = 0.001). Levels of all contact system markers remained unchanged during hemodialysis with all types of dialyzer membranes. CONCLUSION: Routine hemodialysis using systemic heparin anticoagulation induces coagulation activation without measurable contact system activation.

Patients' experiences of transitioning between different renal replacement therapy modalities: A qualitative study.

BACKGROUND: Different kidney replacement therapy modalities are available to manage end-stage kidney disease, such as home-based dialysis, in-center hemodialysis, and kidney transplantation. Although transitioning between modalities is common, data on how patients experience these transitions are scarce. This study explores patients' perspectives of transitioning from a home-based to an in-center modality. METHODS: Patients transitioning from peritoneal dialysis to in-center hemodialysis were purposively selected. Semi-structured interviews were performed, digitally recorded, and transcribed verbatim. Data analysis, consistent with Charmaz' constructivist approach of grounded theory was performed. RESULTS: Fifteen patients (10 males; mean age 62 years) participated. The conditions of the transitioning process impacted the participants' experiences, resulting in divergent experiences and associated emotions. Some participants experienced a loss of control due to the therapy-related changes. Some felt tied down and having lost independence, whereas others stated they regained control as they felt relieved from responsibility. This paradox of control was related to the patient having or not having (1) experienced a fit of hemodialysis with their personal lifestyle, (2) a frame of reference, (3) higher care requirements, (4) insight into the underlying reasons for transitioning, and (5) trust in the healthcare providers. CONCLUSIONS: Care teams need to offer opportunities to elicit patients' knowledge and fears, dispel myths, forge connections with other patients, and visit the dialysis unit before transition to alleviate anxiety. Interventions that facilitate a sense of control should be grounded in the meaning that the disorder has for the person and how it impacts their sense of self.

Utility of Baseline Home Visit Audit in Home Hemodialysis.

We conducted a retrospective cohort study in a university hospital-based home hemodialysis (HHD) program to evaluate the effectiveness of a home visit audit tool. We aimed to delineate safety risk in HHD patients and to ascertain whether this is associated with clinical outcomes. All incident HHD patients between July 18, 2008, and June 30, 2013 with follow-up until December 31, 2013, were included in the cohort. Primary outcome was the description of the presence of safety risk evaluated by the home visit audit at the start of HHD. Secondary outcomes were patient-reported adverse events and technique survival. In our cohort of 84 patients, a baseline home visit audit was surveyed in 56 (67%) patients. Overall, patients were 45.8 ± 14.1 years old, and 51.2% were men. Eighteen of the 35 potential safety risks were documented at least once in the cohort. Thrity-three of the 56 surveyed subjects presented more than one safety risk. The performance of an audit did not influence adverse events or technique survival. Process and methods of auditing a home visit should be reviewed to improve judicious resource use.

Peritoneal Dialysis for Chronic Congestive Heart Failure.

Maladaptive responses between a failing heart and the kidneys ultimately lead to permanent chronic kidney disease, referred to as cardiorenal syndrome type 2. In this narrative review, we discuss the pathophysiological pathways in the progression of cardiorenal failure and review the current evidence on peritoneal dialysis as a treatment strategy in cardiorenal syndrome type 2. A patient with heart failure can present with clinical symptoms related to venous congestion even in the absence of end-stage renal disease. Diuretics remain the cornerstone for the treatment of fluid overload related to heart failure. However, with chronic use, diuretic resistance can supervene. When medical therapy is no longer able to relieve congestive symptoms, ultrafiltration might be needed. Patients with heart failure tolerate well the gentle rate of fluid removal through peritoneal dialysis. Recent publications suggest a positive impact of starting peritoneal dialysis in patients with cardiorenal syndrome type 2 on the hospitalisation rate, functional status and quality of life.

Evaluating the benefits of home-based peritoneal dialysis.

Peritoneal dialysis (PD) is an effective renal replacement strategy for patients suffering from end-stage renal disease. PD offers patient survival comparable to or better than in-center hemodialysis while preserving residual kidney function, empowering patient autonomy, and reducing financial burden to payors. The majority of patients suffering from kidney failure are eligible for PD. In patients with cardiorenal syndrome and uncontrolled fluid status, PD is of particular benefit, decreasing hospitalization rates and duration. This review discusses the benefits of chronic PD, performed by the patient or a caregiver at home. Recognition of the benefits of PD is a cornerstone in stimulating the use of this treatment strategy.

Avoidance of systemic anticoagulation during intermittent haemodialysis with heparin-grafted polyacrilonitrile membrane and citrate-enriched dialysate: a retrospective cohort study.

BACKGROUND: Since October 2010, the combination of a heparin-grafted polyacrilonitrile (AN69ST) membrane with a 0.80 mmol/L citric acid-containing dialysate is routinely used in our centre for intermittent haemodialysis, without systemic anticoagulation, in critically ill patients with increased bleeding risk. The primary outcome of this retrospective cohort study was to assess the development of circuit clotting during these dialysis procedures. Secondly, we assessed the impact of clotting on treatment duration, the incidence rate of coagulation-induced retransfusion failure and the association of patient and dialysis characteristics with the occurrence of clotting. METHODS: Dialysis and patient data on consecutive intermittent haemodialysis procedures, performed at the Intensive Care Unit of Universitair Ziekenhuis Brussel between October 2010 and March 2012, were retrospectively reviewed. We used descriptive statistics as well as a random effects logit model with patient identity as a panel variable to assess associations. RESULTS: Of a total of 309 treatments combining a heparin-grafted AN69ST membrane and a 0.8 mmol/L citric acid-enriched dialysate in 94 patients, circuit clotting was reported in 17.5% (95% CI 13.2% to 21.7%; N = 54), and in 19% (95% CI 13.6% to 24.4%; N = 40) of sessions with prescribed treatment time ≥ 4 hours (N = 210). Clotting shortened treatment time in 15.2% (95% CI 11.4% to 19.7%; N = 47) of sessions by a median of 55 (IQR 20 to 80) minutes. Complete clotting of the circuit with inability for retransfusion occurred in 4.2% (95% CI 2.2% to 7.0%; N = 13) of sessions. Circuit coagulation was not associated with APACHE II score, patient age, gender, number of treatments, type of vascular access or ultrafiltration rate. CONCLUSION: Intermittent haemodialysis without systemic anticoagulation combining a heparin-grafted AN69ST dialyzer with a citrate-enriched dialysate favourably compares as to clotting complications with the published outcomes of anticoagulation-free intermittent haemodialysis strategies using saline flushes, heparin-coated dialyzer in combination with regular dialysate or regional citrate anticoagulation with calcium supplemented dialysate. The incidence of circuit clotting in our cohort appears to be higher than previously reported for regional citrate anticoagulation with a calcium-free dialysate.