Total Kidney Volume in Autosomal Dominant Polycystic Kidney Disease: A Biomarker of Disease Progression and Therapeutic Efficacy.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common potentially life-threatening monogenic disorder in humans, characterized by progressive development and expansion of fluid-filled cysts in the kidneys and other organs. Ongoing cyst growth leads to progressive kidney enlargement, whereas kidney function remains stable for decades as a result of hyperfiltration and compensation by unaffected nephrons. Kidney function irreversibly declines only in the late stages of the disease, when most of the parenchyma is lost to cystic and fibrotic tissue and the remaining compensatory capacity is overwhelmed. Hence, conventional kidney function measures, such as glomerular filtration rate, do not adequately assess disease progression in ADPKD, especially in its early stages. Given the recent development of potential targeted therapies in ADPKD, it has become critically important to identify relevant biomarkers that can be used to determine the degree of disease progression and evaluate the effects of therapeutic interventions on the course of the disease. We review the current evidence to provide an informed perspective on whether total kidney volume (TKV) is a suitable biomarker for disease progression and whether TKV can be used as an efficacy end point in clinical trials. We conclude that because cystogenesis is the central factor leading to kidney enlargement, TKV appears to be an appropriate biomarker and is gaining wider acceptance. Several studies have identified TKV as a relevant imaging biomarker for monitoring and predicting disease progression and support its use as a prognostic end point in clinical trials.

Health state utilities associated with major clinical events in the context of secondary hyperparathyroidism and chronic kidney disease requiring dialysis.

BACKGROUND: Patients with chronic kidney disease (CKD) and secondary hyperparathyroidism (SHPT) who require dialysis are at increased risk for cardiovascular events and bone fractures. To assist in economic evaluations, this study aimed to estimate the disutility of these events beyond the impact of CKD and SHPT. METHODS: A basic one-year health state was developed describing CKD and SHPT requiring dialysis. Further health states added acute events (cardiovascular events, fractures, and surgical procedures) or chronic post-event effects. Acute health states described a year including an event, and chronic health states described a year subsequent to an event. General population participants in Canada completed time trade-off interviews from which utilities were derived. Pairwise comparisons were made between the basic state and event, and between comparable health states. RESULTS: A total of 199 participants (54.8% female; mean age = 46.3 years) completed interviews. Each health state had ≥130 valuations. The mean (SD) utility of the basic health state was 0.60 (0.34). For acute events, mean utility differences versus the basic state were: myocardial infarction, -0.06; unstable angina, -0.05; peripheral vascular disease (PVD) with amputation, -0.33; PVD without amputation, -0.11; heart failure, -0.14; stroke, -0.30; hip fracture, -0.14; arm fracture, -0.04; parathyroidectomy, +0.02; kidney transplant, +0.06. Disutilities for chronic health states were: stable angina, -0.09; stroke, -0.27; PVD with amputation, -0.30; PVD without amputation, -0.12; heart failure, -0.14. CONCLUSIONS: Cardiovascular events and fractures were associated with lower utility scores, suggesting a perceived decrease in quality of life beyond the impact of CKD and SHPT.

The cost-effectiveness of contemporary home haemodialysis modalities compared with facility haemodialysis: a systematic review of full economic evaluations.

AIM: The financial burden of the increasing dialysis population challenges healthcare resources internationally. Home haemodialysis offers many benefits over conventional facility dialysis including superior clinical, patient-centred outcomes and reduced cost. This review updates a previous review, conducted a decade prior, incorporating contemporary home dialysis techniques of frequent and nocturnal dialysis. We sought comparative cost-effectiveness studies of home versus facility haemodialysis (HD) for people with end-stage kidney failure (ESKF). METHODS: We conducted a systematic review of literature from January 2000-March 2014. Studies were included if they provided comparative information on the costs, health outcomes and cost-effectiveness ratios of home HD and facility HD. We searched medical and health economic databases using MeSH headings and text words for economic evaluation and haemodialysis. RESULTS: Six studies of economic evaluations that compared home to facility HD were identified. Two studies compared home nocturnal HD, one home nocturnal and daily home HD, and three compared contemporary home HD to facility HD. Overall these studies suggest that contemporary home HD modalities are less costly and more effective than facility HD. Home HD start-up costs tend to be higher in the short term, but these are offset by cost savings over the longer term. CONCLUSIONS: Contemporaneous dialysis modalities including nocturnal and daily home haemodialysis are cost-effective or cost-saving compared with facility-based haemodialysis. This result is largely driven by lower staff costs, and better health outcomes for survival and quality of life. Expanding the proportion of haemodialysis patients managed at home is likely to produce cost savings.

Pathways for Diagnosing and Treating CKD-Associated Pruritus: A Narrative Review.

Purpose of Review: Chronic kidney disease (CKD)-associated pruritus is a common, persistent, and distressing itch experienced by patients across the CKD spectrum. Although the disorder is associated with adverse outcomes and poor health-related quality of life, it remains underdiagnosed and undertreated. The purpose of this narrative review is to offer health care providers guidance on how to effectively identify, assess, and treat patients with CKD-associated pruritus, with the goal of reducing symptom burden and improving patient-important outcomes, such as quality of life (QoL). Sources of Information: A panel of nephrologists and researchers from across Canada and the United States was assembled to develop this narrative review based on the best available data, current treatment guidelines, and their clinical experiences. Methods: A panel of nephrologists who actively care for patients with pruritus receiving dialysis from across Canada was assembled. Two researchers from the United States were also included based on their expertise in the diagnosis and management of CKD-associated pruritus. Throughout Spring 2023, the panel met to discuss key topics in the identification, assessment, and management of CKD-associated pruritus. Panel members subsequently developed summaries of the pertinent information based on the best available data, current treatment guidelines, and added information on their own clinical experiences. In all cases, approval of the article was sought and achieved through discussion. Key Findings: This narrative review provides pragmatic guidance addressing: (1) methods for screening CKD-associated pruritus, (2) assessing severity, (3) management of CKD-associated pruritus, and (4) suggested areas for future research. The panel developed a 3-pillar framework for proactive assessment and severity scoring in CKD-aP: systematic screening for CKD-associated pruritus (pillar 1), assessment of pruritus intensity (pillar 2), and understanding the impact of CKD-associated pruritus on the patient's QoL (pillar 3). Management of CKD-associated pruritus can include ensuring optimization of dialysis adequacy, achieving mineral metabolism targets (ie, calcium, phosphate, and parathyroid hormone). However, treatment of CKD-associated pruritus usually requires additional interventions. Patients, regardless of CKD-associated pruritus severity, should be counseled on adequate skin hydration and other non-pharmacological strategies to reduce pruritus. Antihistamines should be avoided in favor of evidence-based treatments, such as difelikefalin and gabapentin. Limitations: A formal systematic review (SR) of the literature was not undertaken, although published SRs were reviewed. The possibility for bias based on the experts' own clinical experiences may have occurred. Key takeaways are based on the current available evidence, of which head-to-head clinical trials are lacking. Funding: This work was funded by an arm's length grant from Otsuka Canada Pharmaceutical Inc. (the importer and distributer of difelikefalin in Canada). LiV Medical Education Agency Inc. provided logistical and editorial support.

Motif de la revue: Le prurit associé à l'insuffisance rénale chronique (IRC) est une démangeaison cutanée fréquente, persistante et invalidante que les patients de tout le specter de l'IRC peuvent ressentir. Bien que le prurit soit associé à des effets indésirables et à une mauvaise qualité de vie liée à la santé, il demeure sous-diagnostiqué et sous-traité. L'objectif de cette revue narrative est d'offrir des conseils aux professionnels de la santé sur la façon d'identifier, d'évaluer et de traiter efficacement les patients atteints de prurit associé à l'IRC; ceci dans le but de réduire la charge des symptômes et d'améliorer les résultats importants pour les patients, notamment leur qualité de vie (QdV). Sources de l'information: Un comité de néphrologues et de chercheurs de partout au Canada et des États-Unis a été constitué pour élaborer la présente revue narrative à partir des meilleures données disponibles, des lignes directrices actuelles pour le traitement et de leurs expériences cliniques. Méthodologie: Un groupe de néphrologues canadiens qui s'occupent activement de patients dialysés souffrant de prurit a été constitué. Deux chercheurs des États-Unis ont été inclus au groupe en raison de leur expertise dans le diagnostic et la prise en charge du prurit associé à l'IRC. Le comité s'est réuni tout au long du printemps 2023 pour discuter de sujets clés en lien avec l'identification, l'évaluation et la prise en charge du prurit associé à l'IRC. Les membres du comité ont par la suite rédigé des résumés des informations pertinentes en se basant sur les meilleures données disponibles et les lignes directrices actuelles pour le traitement, auxquels ils ont ajouté des informations issues de leurs propres expériences cliniques. Dans tous les cas, l'approbation du manuscrit a été sollicitée et obtenue par discussion. Principaux résultats: Cette revue narrative offre des conseils pragmatiques sur les points suivants: (1) les méthodes de dépistage du prurit associé à l'IRC; (2) l'évaluation de sa gravité; (3) sa prise en charge; et (4) les domaines suggérés pour de futures recherches. Le comité a développé un cadre à trois piliers pour l'évaluation proactive du prurit associé à l'IRC et l'établissement d'un score de gravité: le dépistage systématique du prurit associé à l'IRC (pilier 1), l'évaluation de son intensité (pilier 2) et la compréhension de son impact sur la QdV du patient (pilier 3). La prise en charge du prurit associé à l'IRC peut inclure l'optimisation de l'adéquation de la dialyse et l'atteinte des cibles du métabolisme minéral (c.-à-d. calcium, phosphate et hormone parathyroïdienne). Cependant, son traitement nécessite habituellement des interventions supplémentaires. Les patients, quelle que soit la gravité du prurit associé à l'IRC, devraient être avisés d'hydrater adéquatement leur peau et informés des autres stratégies non pharmacologiques afin de réduire le prurit. On devrait éviter les antihistaminiques et les remplacer par des traitements fondés sur des données probantes comme la difélikéfaline et la gabapentine. Limites: Aucune revue systématique de la littérature n'a été formellement entreprise, bien que les revues systématiques publiées aient été examinées. La possibilité d'un biais fondé sur les expériences cliniques des experts est envisageable. Les principales conclusions de cette étude sont fondées sur les données probantes actuellement disponibles, pour lesquelles il n'existe pas d'essais cliniques comparatifs. Financement: Ces travaux ont été financés par une subvention indépendante d'Otsuka Canada Pharmaceutical Inc. (l'importateur et distributeur de la difélikéfaline au Canada). Un soutien logistique et éditorial a été fourni par liV Medical Education Agency Inc.

Canadian Society of Nephrology guidelines for the management of patients with ESRD treated with intensive hemodialysis.

Intensive (longer and more frequent) hemodialysis has emerged as an alternative to conventional hemodialysis for the treatment of patients with end-stage renal disease. However, given the differences in dialysis delivery and models of care associated with intensive dialysis, alternative approaches to patient management may be required. The purpose of this work was to develop a clinical practice guideline for the Canadian Society of Nephrology. We applied the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach for guideline development and performed targeted systematic reviews and meta-analysis (when appropriate) to address prioritized clinical management questions. We included studies addressing the treatment of patients with end-stage renal disease with short daily (≥5 days per week, <3 hours per session), long (3-4 days per week, ≥5.5 hours per session), or long-frequent (≥5 days per week, ≥5.5 hours per session) hemodialysis. We included clinical trials and observational studies with or without a control arm (1990 and later). Based on a prioritization exercise, 6 interventions of interest included optimal vascular access type, buttonhole cannulation, antimicrobial prophylaxis for buttonhole cannulation, closed connector devices, and dialysate calcium and dialysate phosphate additives for patients receiving intensive hemodialysis. We developed 6 recommendations addressing the interventions of interest. Overall quality of the evidence was very low and all recommendations were conditional. We provide detailed commentaries to guide in shared decision making. The main limitation was the very low overall quality of evidence that precluded strong recommendations. Most included studies were small single-arm observational studies. Three randomized controlled trials were applicable, but provided only indirect evidence. Published information for patient values and preference was lacking. In conclusion, we provide 6 recommendations for the practice of intensive hemodialysis. However, due to very low-quality evidence, all recommendations were conditional. We therefore also highlight priorities for future research.

Vascular access for intensive maintenance hemodialysis: a systematic review for a Canadian Society of Nephrology clinical practice guideline.

BACKGROUND: Practices in vascular access management with intensive hemodialysis may differ from those used in conventional hemodialysis. STUDY DESIGN: We conducted a systematic review to inform clinical practice guidelines for the provision of intensive hemodialysis. SETTING & POPULATION: Adult patients receiving maintenance (>3 months) intensive hemodialysis (frequent [≥5 hemodialysis treatments per week] and/or long [>5.5 hours per hemodialysis treatment]). SELECTION CRITERIA FOR STUDIES: We searched EMBASE and MEDLINE (1990-2011) for randomized and observational studies. We also searched conference proceedings (2007-2011). INTERVENTIONS: (1) Central venous catheter (CVC) versus arteriovenous (AV) access, (2) buttonhole versus rope-ladder cannulation, (3) topical antimicrobial cream versus none in buttonhole cannulation, and (4) closed connector devices among CVC users. OUTCOMES: Access-related infection, survival, hospitalization, patency, access survival, intervention rates, and quality of life. RESULTS: We included 23, 7, and 5 reports describing effectiveness by access type, buttonhole cannulation, and closed connector device, respectively. No study directly compared CVC with AV access. On average, bacteremia and local infection rates were higher with CVC compared with AV access. Access intervention rates were higher with more frequent hemodialysis, but access survival did not differ. Buttonhole cannulation was associated with bacteremia rates similar to those seen with CVCs in some series. Topical mupirocin seemed to attenuate this effect. No direct comparisons of closed connector devices versus standard luer-locking devices were found. Low rates of actual or averted (near misses) air embolism and bleeding were reported with closed connector devices. LIMITATIONS: Overall, evidence quality was very low. Limited direct comparisons addressing main review questions, small sample sizes, selective outcome reporting, publication bias, and residual confounding were major factors. CONCLUSIONS: This review highlights several differences in the management of vascular access in conventional and intensive hemodialysis populations. We identify a need for standardization of vascular access outcome reporting and a number of priorities for future research.

Dialysate calcium concentration and mineral metabolism in long and long-frequent hemodialysis: a systematic review and meta-analysis for a Canadian Society of Nephrology clinical practice guideline.

BACKGROUND: Patients treated with conventional hemodialysis (HD) develop disorders of mineral metabolism that are associated with increased morbidity and mortality. More frequent and longer HD has been associated with improvement in hyperphosphatemia that may improve outcomes. STUDY DESIGN: Systematic review and meta-analysis to inform the clinical practice guideline on intensive dialysis for the Canadian Society of Nephrology. SETTING & POPULATION: Adult patients receiving outpatient long (≥5.5 hours/session; 3-4 times per week) or long-frequent (≥5.5 hours/session, ≥5 sessions per week) HD. SELECTION CRITERIA FOR STUDIES: We included clinical trials, cohort studies, case series, case reports, and systematic reviews. INTERVENTIONS: Dialysate calcium concentration ≥1.5 mmol/L and/or phosphate additive. OUTCOMES: Fragility fracture, peripheral arterial and coronary artery disease, calcific uremic arteriolopathy, mortality, intradialytic hypotension, parathyroidectomy, extraosseous calcification, markers of mineral metabolism, diet liberalization, phosphate-binder use, and muscle mass. RESULTS: 21 studies were identified: 2 randomized controlled trials, 2 reanalyses of data from the randomized controlled trials, and 17 observational studies. Dialysate calcium concentration ≥1.5 mmol/L for patients treated with long and long-frequent HD prevents an increase in parathyroid hormone levels and a decline in bone mineral density without causing harm. Both long and long-frequent HD were associated with a reduction in serum phosphate level of 0.42-0.45 mmol/L and a reduction in phosphate-binder use. There was no direct evidence to support the use of a dialysate phosphate additive. LIMITATIONS: Almost all the available information is related to changes in laboratory values and surrogate outcomes. CONCLUSIONS: Dialysate calcium concentration ≥1.5 mmol/L for most patients treated with long and long-frequent dialysis prevents an increase in parathyroid hormone levels and decline in bone mineral density without increased risk of calcification. It seems prudent to add phosphate to the dialysate for patients with a low predialysis phosphate level or very low postdialysis phosphate level until more evidence becomes available.

Factors associated with suboptimal initiation of dialysis despite early nephrologist referral.

BACKGROUND: STARRT recently demonstrated that many patients experience suboptimal dialysis starts (defined as initiation as an inpatient and/or with a central venous catheter), even when followed by a nephrologist for >12 months (NDT 2011). However, STARRT did not identify the factors associated with suboptimal initiation of dialysis. The objectives of this study were to extend the results of STARRT by ascertaining the factors leading to suboptimal initiation of dialysis in patients who were referred at least 12 months prior to commencement of dialysis. METHODS: At each of the three Toronto centers, charts of consecutive incident RRT patients were identified from 1 January 2009 to 31 December 2010, with predetermined data extracted. RESULTS: A total of 436 incident RRT patients were studied; 52.4% were followed by a nephrologist for >12 months prior to the initiation of dialysis. Suboptimal starts occurred in 56.4% of these patients. No attempt at arteriovenous fistula (AVF) or arteriovenous graft (AVG) prior to initiation was made in 65% of these starts. Factors contributing to suboptimal starts despite early referral included patient-related delays (31.25%), acute-on-chronic kidney disease (31.25%), surgical delays (16.41%), late decision-making (8.59%) and others (12.50%). The percentage of optimal starts with early referral among 14 nephrologists ranged from 33 to 72%. CONCLUSIONS: Most patients started dialysis in a suboptimal manner, despite an extended period of pre-dialysis care. Nephrologists should take responsibility for suboptimal initiation of dialysis despite early referral and test methods that attempt to prevent this.

Intensive hemodialysis associates with improved survival compared with conventional hemodialysis.

Patients undergoing conventional maintenance hemodialysis typically receive three sessions per week, each lasting 2.5-5.5 hours. Recently, the use of more intensive hemodialysis (>5.5 hours, three to seven times per week) has increased, but the effects of these regimens on survival are uncertain. We conducted a retrospective cohort study to examine whether intensive hemodialysis associates with better survival than conventional hemodialysis. We identified 420 patients in the International Quotidian Dialysis Registry who received intensive home hemodialysis in France, the United States, and Canada between January 2000 and August 2010. We matched 338 of these patients to 1388 patients in the Dialysis Outcomes and Practice Patterns Study who received in-center conventional hemodialysis during the same time period by country, ESRD duration, and propensity score. The intensive hemodialysis group received a mean (SD) 4.8 (1.1) sessions per week with a mean treatment time of 7.4 (0.87) hours per session; the conventional group received three sessions per week with a mean treatment time of 3.9 (0.32) hours per session. During 3008 patient-years of follow-up, 45 (13%) of 338 patients receiving intensive hemodialysis died compared with 293 (21%) of 1388 patients receiving conventional hemodialysis (6.1 versus 10.5 deaths per 100 person-years; hazard ratio, 0.55 [95% confidence interval, 0.34-0.87]). The strength and direction of the observed association between intensive hemodialysis and improved survival were consistent across all prespecified subgroups and sensitivity analyses. In conclusion, there is a strong association between intensive home hemodialysis and improved survival, but whether this relationship is causal remains unknown.

Management of Type 2 Diabetic Kidney Disease in 2022: A Narrative Review for Specialists and Primary Care.

Purpose of review: Kidney disease is present in almost half of Canadian patients with type 2 diabetes (T2D), and it is also the most common first cardiorenal manifestation of T2D. Despite clear guidelines for testing, opportunities are being missed to identify kidney diseases, and many Canadians are therefore not receiving the best available treatments. This has become even more important given recent clinical trials demonstrating improvements in both kidney and cardiovascular (CV) endpoints with sodium-glucose cotransporter 2 (SGLT2) inhibitors and a nonsteroidal mineralocorticoid receptor antagonist, finerenone. The goal of this document is to provide a narrative review of the current evidence for the treatment of diabetic kidney disease (DKD) that supports this new standard of care and to provide practice points. Sources of information: An expert panel of Canadian clinicians was assembled, including 9 nephrologists, an endocrinologist, and a primary care practitioner. The information the authors used for this review consisted of published clinical trials and guidelines, selected by the authors based on their assessment of their relevance to the questions being answered. Methods: Panelists met virtually to discuss potential questions to be answered in the review and agreed on 10 key questions. Two panel members volunteered as co-leads to write the summaries and practice points for each of the identified questions. Summaries and practice points were distributed to the entire author list by email. Through 2 rounds of online voting, a second virtual meeting, and subsequent email correspondence, the authors reached consensus on the contents of the review, including all the practice points. Key findings: It is critical that DKD be identified as early as possible in the course of the disease to optimally prevent disease progression and associated complications. Patients with diabetes should be routinely screened for DKD with assessments of both urinary albumin and kidney function. Treatment decisions should be individualized based on the risks and benefits, patients' needs and preferences, medication access and cost, and the degree of glucose lowering needed. Patients with DKD should be treated to achieve targets for A1C and blood pressure. Renin-angiotensin-aldosterone system blockade and treatment with SGLT2 inhibitors are also key components of the standard of care to reduce the risk of kidney and CV events for these patients. Finerenone should also be considered to further reduce the risk of CV events and chronic kidney disease progression. Education of patients with diabetes prescribed SGLT2 inhibitors and/or finerenone is an important component of treatment. Limitations: No formal guideline process was used. The practice points are not graded and are not intended to be viewed as having the weight of a clinical practice guideline or formal consensus statement. However, most practice points are well aligned with current clinical practice guidelines.

Justification: L'insuffisance rénale est présente chez près de la moitié des patients canadiens atteints de diabète de type 2 (DT2). Il s'agit également de la première manifestation cardiorénale la plus fréquente du DT2. Bien qu'il existe des lignes directrices claires pour son dépistage, des occasions de diagnostiquer l'insuffisance rénale sont manquées, ce qui fait en sorte que de nombreux Canadiens ne reçoivent pas les meilleurs traitements disponibles. Cette préoccupation a pris de l'importance puisque de récents essais cliniques ont démontré des améliorations dans les paramètres rénaux et cardiovasculaires (CV) avec la prise de finérénone, un antagoniste non stéroïdien des récepteurs minéralocorticoïdes (nsMRA), et d'inhibiteurs du cotransporteur de glucose de sodium 2 (SGLT2). L'objectif de cet article est de fournir une revue narrative des données probantes actuelles appuyant cette nouvelle norme de soins pour le traitement de l'insuffisance rénale diabétique (IRD), ainsi que des points de pratique. Sources de l'information: Un groupe d'experts composé de cliniciens canadiens, dont neuf néphrologues, un endocrinologue et un prestataire de soins primaires, a été formé. Les auteurs de cette revue ont utilisé des lignes directrices et des essais cliniques publiés comme sources; ceux-ci ont été choisis sur la base d'une évaluation de leur pertinence pour les questions auxquelles ils avaient répondu. Méthodologie: Les panélistes se sont réunis virtuellement pour discuter de potentielles questions à répondre dans le cadre de cette revue, et se sont entendus sur dix questions clés. Deux membres du panel se sont portés volontaires pour être co-responsables et rédiger les résumés et les points de pratique pour chacune des questions identifiées. Ces derniers ont été distribués par courriel à l'ensemble des auteurs. Après deux tours de vote en ligne, une deuxième réunion virtuelle et la correspondance électronique qui a suivi, les auteurs sont parvenus à un consensus sur le contenu de la revue narrative, y compris sur tous les points de pratique. Principaux résultats: Il est essentiel que l'IRD soit diagnostiquée le plus tôt possible afin de prévenir de façon optimale la progression de la maladie et les complications qui y sont associées. On devrait procéder au dépistage systématique de l'IRD chez les patients diabétiques par l'évaluation de l'albumine urinaire ET de la fonction rénale. Les décisions relatives au traitement devraient être individualisées en fonction des risques et des avantages pour le patient, de ses besoins et préférences, de l'accès aux médicaments et des coûts, ainsi que du degré nécessaire de réduction de la glycémie. Les patients atteints d'IRD devraient être traités pour atteindre les cibles d'A1c et de pression artérielle. Le blocage du SRAA et le traitement avec des inhibiteurs du SGLT2 sont également des composantes clés de la norme de soins visant à réduire le risque d'événements rénaux et CV pour ces patients. La finérénone devrait également être envisagée pour réduire encore davantage les risques d'événements CV et de progression vers l'IRC. L'éducation des patients diabétiques auxquels on prescrit des inhibiteurs du SGLT2 et/ou de la finérénone est un élément important du traitement. Limites: Aucun processus officiel de directives n'a été utilisé. Les points de pratique ne sont pas notés et ne sont pas destinés à être considérés comme ayant le poids d'une directive de pratique clinique ou d'une déclaration de consensus officielle. Cependant, la plupart des points de pratique sont bien alignés avec les lignes directrices actuelles de pratique clinique.

Pulmonary vascular calcification in a nocturnal hemodialysis patient.

Although vascular calcification in end-stage renal disease (ESRD) is common, metastatic pulmonary calcification (MPC) is an under-recognized complication of ESRD with the majority of individuals being asymptomatic. Similar to calcification in other arterial vascular beds, elevated serum calcium and phosphate appear to be potent risk factors although the exact pathogenesis of MPC remains largely unclear. Nocturnal hemodialysis (NHD) is a form of renal replacement therapy that offers superior control of serum phosphate and uremia compared to conventional (3 times weekly) intermittent hemodialysis and shows promise in delaying the progression of vascular calcification. Here, we report the first case of MPC involving the pulmonary vasculature in a patient treated with nocturnal hemodialysis and discuss the epidemiology, pathogenesis, histology and natural history of MPC.

Regression of left ventricular mass following conversion from conventional hemodialysis to thrice weekly in-centre nocturnal hemodialysis.

BACKGROUND: Increased left ventricular mass (LVM) is associated with adverse outcomes in patients receiving chronic hemodialysis. Among patients receiving conventional hemodialysis (CHD, 3×/week, 4 hrs/session), we evaluated whether dialysis intensification with in-centre nocturnal hemodialysis (INHD, 3×/week, 7-8 hrs/session in the dialysis unit) was associated with regression of LVM. METHODS: We conducted a retrospective cohort study of CHD recipients who converted to INHD and received INHD for at least 6 months. LVM on the first echocardiogram performed at least 6 months post-conversion was compared to LVM pre-conversion. In a secondary analysis, we examined echocardiograms performed at least 12 months after starting INHD. The effect of conversion to INHD on LVM over time was also evaluated using a longitudinal analysis that incorporated all LVM data on patients with 2 or more echocardiograms. RESULTS: Thirty-seven patients were eligible for the primary analysis. Mean age at conversion was 49 ± 12 yrs and 30% were women. Mean pre-conversion LVM was 219 ± 66 g and following conversion, LVM declined by 32 ± 58 g (p = 0.002). Among patients whose follow-up echocardiogram occurred at least 12 months following conversion, LVM declined by 40 ± 56 g (p = 0.0004). The rate of change of LVM decreased significantly from 0.4 g/yr before conversion, to -11.7 g/yr following conversion to INHD (p < 0.0001). CONCLUSION: Conversion to INHD is associated with a significant regression in LVM, which may portend a more favourable cardiovascular outcome. Our preliminary findings support the need for randomized controlled trials to definitively evaluate the cardiovascular effects of INHD.

Hemodialysis vascular access modifies the association between dialysis modality and survival.

Several comparisons of peritoneal dialysis (PD) and hemodialysis (HD) in incident patients with ESRD demonstrate superior survival in PD-treated patients within the first 1 to 2 years. These survival differences may be due to higher HD-related mortality as a result of high rates of incident central venous catheter (CVC) use or due to an initial survival advantage conferred by PD. We compared the survival of incident PD patients with those who initiated HD with a CVC (HD-CVC) or with a functional arteriovenous fistula or arteriovenous graft (HD-AVF/AVG). We used multivariable piece-wise exponential nonproportional and proportional hazards models to evaluate early (1 year) mortality as well as overall mortality during the period of observation using an intention-to-treat approach. We identified 40,526 incident adult dialysis patients from the Canadian Organ Replacement Register (2001 to 2008). Compared with the 7412 PD patients, 1-year mortality was similar for the 6663 HD-AVF/AVG patients but was 80% higher for the 24,437 HD-CVC patients (adjusted HR, 1.8; 95% confidence intervals [CI], 1.6 to 1.9). During the entire period of follow-up, HD-AVF/AVG patients had a lower risk for death, and HD-CVC patients had a higher risk for death compared with patients on PD. In conclusion, the use of CVCs in incident HD patients largely accounts for the early survival benefit seen with PD.

Nocturnal hemodialysis: effects on solute clearance, quality of life, and patient survival.

PURPOSE OF REVIEW: Conventional hemodialysis is often an incomplete treatment for uremia. People receiving hemodialysis often report a poor quality of life and suffer from an accelerated mortality rate. Nocturnal hemodialysis provides long treatments at night in the home or dialysis center. This review will examine how long nocturnal treatments have impact on the clearance of small and larger retention products, and how these treatments influence quality of life and survival. RECENT FINDINGS: Nocturnal hemodialysis is more effective at clearing most small and middle molecule retention products, and has been associated with improvements in quality of life, especially in those domains related to the effects of kidney disease. Survival on nocturnal hemodialysis is higher than expected, and studies suggest that patients receiving nocturnal hemodialysis have a mortality rate that is about one third of what is seen in similar patients receiving conventional hemodialysis. SUMMARY: Although impressive, it is difficult to be sure how much of the results of these studies is due to the duration and timing of dialysis and how much relates to patient level factors and residual confounding, and further research in this area is required.

Suboptimal initiation of dialysis with and without early referral to a nephrologist.

BACKGROUND: Our objective was to examine patients who initiate renal replacement therapy (RRT) at 10 representative Canadian centers, characterize their initiation as inpatient or outpatient and describe their initial type of dialysis access, duration of pre-dialysis care and clinical status at the time of dialysis initiation. We also examined the impact of an optimal dialysis start (i.e. initiated as an outpatient with an arteriovenous fistula, arteriovenous graft or peritoneal dialysis catheter) on subsequent health outcomes. METHODS: Charts of consecutive incident RRT patients were identified from 1 July to 31 December 2006. Information was collected until 6 months after the initiation or until death, transplant or transfer. RESULTS: Three hundred and thirty-nine incident RRT patients were studied: 39.6% initiated as an inpatient; 54% started hemodialysis (HD) with a central venous catheter; 15.3% had <1 month predialysis care, while 64.6% had >1 year. Optimal starts occurred in 39.5% of patients. For HD patients, optimal starts occurred in 19.8%. Suboptimal starts were noted in patients referred <12 months prior to end-stage renal disease (44%) and in patients referred earlier (56%). The composite end point of death, transfusion or subsequent hospitalization was significantly reduced with an optimal start [hazard ratio 0.47 (95% confidence interval 0.32-0.68), P = 0.0001]. CONCLUSIONS: Suboptimal initiation of dialysis is common in patients referred early or late. The benefits of early referral are lost if dialysis is initiated suboptimally. There is a need to identify factors that lead to suboptimal initiation despite early referral.

Making the Correct Diagnosis in Thrombotic Microangiopathy: A Narrative Review.

PURPOSE OF REVIEW: Thrombotic microangiopathy (TMA) is suspected in patients presenting with thrombocytopenia and evidence of a microangiopathic hemolytic anemia. Patients with TMA can be critically ill, so rapid and accurate identification of the underlying etiology is essential. Due to better insights into pathophysiology and causes of TMA, we can now categorize TMAs as thrombotic thrombocytopenic purpura, postinfectious (mainly Shiga toxin-producing Escherichia coli-induced) hemolytic uremic syndrome (HUS), TMA associated with a coexisting condition, or atypical HUS (aHUS). We recognized an unmet need in the medical community to guide the timely and accurate identification of TMA, the selection of tests to clarify its etiology, and the sequence of steps to initiate treatment. SOURCES OF INFORMATION: Key published studies relevant to the identification, classification, and treatment of TMAs in children or adults. These studies were obtained through literature searches conducted with PubMed or based on the prior knowledge of the authors. METHODS: This review is the result of a consultation process that reflects the consensus of experts from Canada, the United States, and the United Arab Emirates. The members represent individuals who are clinicians, researchers, and teachers in pediatric and adult medicine from the fields of hematology, nephrology, and laboratory medicine. Authors, through an iterative review process identified and synthesized information from relevant published studies. KEY FINDINGS: Thrombotic thrombocytopenic purpura occurs in the setting of insufficient activity of the von Willebrand factor protease known as ADAMTS13. Shiga toxin-producing Escherichia coli-induced hemolytic uremic syndrome, also known as "typical" HUS, is caused by gastrointestinal infections with bacteria that produce Shiga toxin (initially called verocytotoxin). A variety of clinical conditions or drug exposures can trigger TMA. Finally, aHUS occurs in the setting of inherited or acquired abnormalities in the alternative complement pathway leading to dysregulated complement activation, often following a triggering event such as an infection. It is possible to break the process of etiological diagnosis of TMA into 2 distinct steps. The first covers the initial presentation and diagnostic workup, including the processes of identifying the presence of TMA, appropriate initial tests and referrals, and empiric treatments when appropriate. The second step involves confirming the etiological diagnosis and moving to definitive treatment. For many forms of TMA, the ultimate response to therapies and the outcome of the patient depends on the rapid and accurate identification of the presence of TMA and then a standardized approach to seeking the etiological diagnosis. We present a structured approach to identifying the presence of TMA and steps to identifying the etiology including standardized lab panels. We emphasize the importance of early consultation with appropriate specialists in hematology and nephrology, as well as identification of whether the patient requires plasma exchange. Clinicians should consider appropriate empiric therapies while following the steps we have recommended toward definitive etiologic diagnosis and management of the TMA. LIMITATIONS: The evidence base for our recommendations consists of small clinical studies, case reports, and case series. They are generally not controlled or randomized and do not lend themselves to a stricter guideline-based methodology or a Grading of Recommendations Assessment, Development and Evaluation (GRADE)-based approach.

JUSTIFICATION: La microangiopathie thrombotique (MAT) est suspectée chez les patients présentant une thrombocytopénie et la preuve d'une anémie hémolytique microangiopathique (AHMA). Les patients atteints de MAT peuvent être gravement malades, il est donc essentiel de déterminer rapidement et précisément l'étiologie sous-jacente. Grâce à une meilleure connaissance de la physiopathologie et des causes de la MAT, nous pouvons désormais classer les MAT par catégorie: purpura thrombocytopénique thrombotique (PTT), syndrome hémolytique urémique post-infectieux (SHU) principalement induit par STEC (Escherichia coli produisant la toxine Shiga), ou MAT associée à une affection coexistante ou à un SHU atypique (SHUa). Nous avons constaté un besoin dans la communauté médicale pour guider à la fois la détection rapide et précise de la MAT, la sélection des tests pour clarifier son étiologie et la séquence des étapes menant à l'initiation du traitement. SOURCES: Des recherches documentaires sur PubMed et les connaissances antérieures des auteurs ont permis de colliger les principales études publiées portant sur la détection, la classification et le traitement de la MAT chez les enfants ou les adultes. MÉTHODOLOGIE: Cet examen est le résultat d'un processus de consultation qui reflète le consensus des experts du Canada, des États-Unis et des Émirats arabes Unis. Les membres représentent des cliniciens, des chercheurs et des enseignants en médecine pédiatrique et adulte dans les domaines de l'hématologie, de la néphrologie et de la médecine de laboratoire. Les auteurs, par le biais d'un processus d'examen itératif, ont colligé et synthétisé l'information provenant des études publiées jugées pertinentes. PRINCIPAUX RÉSULTATS: Le PTT survient lors d'une activité insuffisante de la protéase du facteur Willebrand connue sous le nom d'ADAMTS13. Le SHU-STEC, aussi appelé SHU « typique ¼, est causé par des infections gastro-intestinales dues à des bactéries produisant la toxine Shiga (initialement appelée vérocytotoxine). Plusieurs états pathologiques ou expositions à des médicaments peuvent déclencher la MAT. Quant au SHU atypique (SHUa), il survient en présence d'anomalies héréditaires ou acquises de la voie du complément alternatif qui mènent à un dérèglement de l'activation du complément, souvent à la suite d'un événement déclencheur comme une infection. On peut diviser le processus de diagnostic étiologique de la MAT en deux étapes distinctes. La première couvre la présentation initiale et le diagnostic, y compris les processus de détection de la MAT, les tests initiaux et aiguillages appropriés, ainsi que les traitements empiriques si nécessaire. La deuxième étape consiste à confirmer le diagnostic étiologique et à procéder au traitement définitif. Pour de nombreuses formes de MAT, la réponse ultime aux traitements et le résultat du patient dépendent de la détection rapide et précise de la MAT et ensuite, d'une approche standardisée pour la recherche du diagnostic étiologique. Nous présentons une approche structurée pour détecter la présence de MAT ainsi qu'une démarche pour rechercher l'étiologie, y compris des tableaux de laboratoire normalisés. Nous soulignons l'importance d'une consultation précoce avec les spécialistes appropriés en hématologie et en néphrologie, et de la détermination d'un éventuel besoin d'échange de plasma (PLEX) pour le patient. Les cliniciens devraient envisager les traitements empiriques appropriés tout en suivant la démarche que nous recommandons pour le diagnostic étiologique définitif et la gestion de la MAT. LIMITES: La base factuelle de nos recommandations est constituée de petites études cliniques, de rapports de cas et de séries de cas. Ces études ne sont généralement pas contrôlées ou randomisées et ne se prêtent pas à une méthodologie plus stricte basée sur des lignes directrices ni à une approche fondée sur le GRADE (Grading of Recommendations Assessment, Development and Evaluation).

International trends in erythropoietin use and hemoglobin levels in hemodialysis patients.

Hemoglobin levels and the dose of erythropoiesis-stimulating agents (ESAs) have risen over time in hemodialysis patients within the United States. There are concerns that these trends may be driven by reimbursement policies that provide potential incentives to increase this use. To determine this we studied trends in the use of ESA and hemoglobin levels in hemodialysis patients and the relationship of these trends to the mode of reimbursement. Using the Dialysis Outcomes and Practice Patterns Study (DOPPS) database of hemodialysis we analyzed facility practices in over 300 randomly selected dialysis units in 12 countries. At each of three phases (years 1996-2001, 2002-2004, and 2005-present), we randomly selected over 7500 prevalent hemodialysis, hemofiltration, or hemodiafiltration patients. ESA usage rose significantly in every country studied except Belgium. All but Sweden demonstrated a substantial increase in hemoglobin levels. In 2005 more than 40% of patients had hemoglobin levels above the KDOQI upper target limit of 120 g/l in all but Japan. These trends appeared to be independent of the manner of reimbursement even though the United States is the only country with significant financial incentives promoting increased use of these agents. Thus, our study found that prescribing higher doses of ESAs and achieving higher hemoglobin levels by physicians reflects a broad trend across DOPPS countries regardless of the reimbursement policies.

Should patients remain on intensive hemodialysis rather than choosing to receive a kidney transplant?

Most dialysis patients would choose to receive a kidney transplant if possible. However, some patients who are receiving intensive hemodialysis (HD) have opted against transplantation and have chosen to remain on dialysis. In this paper, we examine studies that help to inform the decision between receiving a kidney transplant and remaining on intensive HD. There are no randomized trials directly comparing transplant to intensive HD. Database and prospective nonrandomized studies support a number of conclusions. First, compared to conventional HD, survival appears to be better with either transplantation or intensive HD. Survival appears to be similar between intensive HD and deceased donor kidney transplantation, but the best survival is reported with live donor transplantation. Secondly, people with a kidney transplant or receiving intensive HD report a higher quality of life than people on conventional HD. There is insufficient evidence to determine whether there are significant quality of life differences between these treatments. Finally, the costs of intensive HD compare favorably to those of conventional HD. Renal transplantation is more costly in the first year, but after about 2 years should be less costly than any form of HD. Based on these studies eligible intensive HD patients should be encouraged to pursue transplantation, especially live kidney donor transplantation. Individual concerns about the relative risks and benefits of renal transplantation may drive some patients to choose to stay on dialysis. Clinicians should explore the reasons behind such a decision to ensure that the patient is properly informed; however, appropriately reasoned decisions should be respected.

Glutathione and riboflavin status in supplemented patients undergoing home nocturnal hemodialysis versus standard hemodialysis.

BACKGROUND: Patients on conventional hemodialysis (HD) have elevated markers of oxidative stress and chronic inflammation, which may contribute to a high prevalence of cardiovascular disease. Glutathione (GSH), an important intracellular antioxidant, requires cysteine as a rate-limiting amino acid for its synthesis and riboflavin for its regeneration. OBJECTIVES: We aimed to examine whether erythrocyte GSH (eGSH) concentrations and riboflavin status are influenced by the increased dialysis dose provided to vitamin-supplemented patients receiving home nocturnal hemodialysis (HNHD) (6-8 hours/session, 5-7 nights/week) compared with patients on standard hemodialysis (SHD) (4 hours/session, 3 days/week). METHOD: This was a cross-sectional comparative study involving 30 patients undergoing SHD or HNHD regimens and a group of 15 healthy control subjects (HC). We measured eGSH concentration by liquid chromatography-tandem mass spectrometry, riboflavin status by eGSH reductase activity coefficient (EGRAC) as well as plasma total cysteine (Cys) and total homocysteine (Hcy), vitamin C by high-performance liquid chromatography, and C-reactive protein (CRP) by standard method. Estimated dietary protein and energy intakes were determined by 3-day food records, and nutritional status was assessed by subjective global assessment (SGA). RESULTS: There were no significant differences among groups in eGSH concentration, EGRAC, dietary protein intake, and SGA score. SHD patients had significantly higher plasma Cys (P < .001) and Hcy compared with HNHD and HC groups (P = .048). Vitamin C was significantly lower (P = .01) and CRP significantly higher (P = .048) in both HD groups compared with HC. CONCLUSION: eGSH concentration appears to be unaffected by dialysis dose in well-nourished HD patients.

Update to Evidence-Based Secondary Prevention Strategies After Acute Coronary Syndrome.

A recent acute coronary syndrome provides an opportunity to optimise secondary prevention strategies to reduce the risk of future cardiovascular events. This review provides an updated synopsis of current evidence-based approaches. New clinical trial data on the use of antiplatelet and anticoagulants allow choices of the selection and duration of treatment. Lipid lowering after an acute coronary syndrome is now enhanced, with proprotein convertase subtilisin-kexin type 9 inhibitors providing added benefit on top of statin and ezetimibe treatment in high-risk patients. In addition, a recent trial of icosapent ethyl, a highly purified ethyl ester of eicosapentaenoic acid, addresses residual risk in patients with elevated triglycerides already treated with statins. The use of both sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes reduces cardiovascular events independently of glucose lowering.

La survenue récente d'un syndrome coronarien aigu offre l'occasion d'optimiser les stratégies de prévention secondaire en vue de réduire le risque d'événements cardiovasculaires futurs. Le présent article de synthèse offre une vue d'ensemble actualisée des approches contemporaines fondées sur des données probantes. Les nouvelles données d'essais cliniques sur l'utilisation d'antiplaquettaires et d'anticoagulants permettent de choisir un traitement et sa durée. La réduction des lipides après la survenue d'un syndrome coronarien aigu se trouve maintenant améliorée, les bienfaits des inhibiteurs de la proprotéine convertase subtilisine/kexine de type 9 s'ajoutant à ceux du traitement par des statines et l'ézétimibe chez les patients à haut risque. En outre, un essai récent portant sur l'icosapent éthyl, un ester éthylique hautement purifié de l'acide eicosapentaénoïque, aborde le risque résiduel chez les patients présentant une hypertriglycéridémie déjà traités par des statines. L'utilisation d'inhibiteurs du cotransporteur sodium-glucose de type 2 et d'agonistes des récepteurs du peptide-1 apparenté au glucagon chez les patients atteints de diabète de type 2 limite les événements cardiovasculaires indépendamment de la diminution de la glycémie.