Kidney and Dialysis

Background: Whether patients commence haemodialysis with a central venous catheter (CVC), or an arteriovenous fistula (AVF) is used to audit the quality of a vascular access service. However, this crude metric of measurement can miss the increasing nuance and complexity of vascular access planning. We aimed to understand whether commencing haemodialysis with a CVC represented an ‘optimal’ or ‘suboptimal’ outcome and how this could influence the assessment of a vascular access service. Methods: From a prospective clinical database, patients known to nephrology >90 days prior to initiating haemodialysis as first-ever renal replacement therapy (2011–2020) from a single centre were included. Results: A total of 158/254 patients started haemodialysis with a CVC, and 96 with arteriovenous fistula. For 91 patients, the CVC was deemed ‘optimal’ care due to factors such as unpredictable deterioration in renal function (n = 41) and inadequate veins for AVF creation (n = 24). For 67 patients, the CVC was ‘suboptimal’ due to factors such as no/late referral to access assessment (n = 25) and delays in the AVF creation pathway (n = 13). There was no difference in mean survival between the AVF and ‘suboptimal’ groups (2.53 vs. 2.21 years, p = 0.31). There was a survival difference between AVF versus CVC (2.53 vs. 1.97 years, p = 0.002) and ‘suboptimal’ versus ‘optimal’ CVC cohorts (2.21 vs. 1.40 years, p = 0.16). Conclusions: Understanding whether a CVC is ‘optimal’ or ‘suboptimal’ allows a more nuanced analysis of service provision. High mortality in the ‘optimal’ group suggests a frailer cohort where CVC is potentially the best care. Studying ‘suboptimal’ CVC starts helps identify practice and system issues preventing ‘optimal’ care. Full article

Background: For our society, chronic kidney disease is a major public health problem associated with high mortality, morbidity, reduced quality of life and a progressive increase in health costs. The aim of this study was to analyze and compare the current cost of kidney transplantation (KT) and kidney–pancreas transplantation (KPT) among the different Regional Health Services (RHS) in Spain. Methods: A descriptive comparative study analyzing the public prices of RHS in Spain. The Official Gazette of the different communities was consulted, where the latest available order on this type of cost was sought. A descriptive analysis was made of the stipulated cost of the KT and KPT, for each degree of severity, RHS, year of publication and cost calculation method. Mean cost and standard deviation were calculated. Results: KT prices were found for 15 of the 18 RHS (83.33%). The average cost of KT in Spain was EUR 33,926.53 ± 6950.053 (range from EUR 23,140.37 in the Canary Islands to EUR 48,205.75 in Catalonia). For KPT, costs were found for 5 of the 18 RHS (27.8%). The mean cost of KPT was EUR 65,792.38 ± 11,273.12 (ranging from EUR 49,418.81 in Navarra to EUR 78,363.20 in Andalusia). Conclusions: There is a large variability in KT and KPT costs in Spain between RHS. Our study underlines the importance of adopting standardized and updated costing methods for KT and KPT. Full article

The history of sodium-glucose cotransporter 2 inhibitors (SGLT2i) is so long and started in 1835 when Petersen extracted a compound called phlorizin from apple tree bark. About fifty years later, von Mering discovered its glucosuric properties. In the 1980s, it was discovered that the glucosuria resulted from inhibition by phlorizin of glucose reabsorption by the renal tubules, which lowered blood glucose levels in diabetic rats. Nowadays, beyond their glucose-lowering effects, growing evidence suggests significant cardiorenal benefits associated with SGLT2i therapy. Indeed, several clinical trials, including landmark studies such as EMPA-REG OUTCOME, CANVAS Program, and DECLARE-TIMI 58, have demonstrated robust reductions in cardiovascular events, particularly heart failure hospitalizations and cardiovascular mortality, among patients treated with SGLT2i. However, subsequent trials showed that SGLT2i benefits extend beyond the diabetic population, encompassing individuals with and without diabetes. Additionally, SGLT2i exhibit nephroprotective effects, manifesting as a slowing of the progression of chronic kidney disease and a reduction in the risk of end-stage kidney disease. The mechanisms underlying the cardiorenal benefits of SGLT2i are multifactorial and include improvements in glycemic control, reduction in arterial stiffness, modulation of inflammation and oxidative stress, reduction of intraglomerular pression and promotion of natriuresis and diuresis through inhibition of SGLT2 in the luminal brush border of the first segments of the proximal kidney tubule. This narrative review aims to explore the cardiorenal outcomes of SGLT2i, encompassing their mechanisms of action, clinical evidence, safety profile, and implications for clinical practice. Full article

Despite the lack of evidence that suggests hemodiafiltration (HDF) offers a better survival outcome than standard hemodialysis (HD), the number of patients initiating HDF in Japan continues to rise. This study examined the temporal change in the number of HDF incidents, evaluated factors associated with all-cause mortality, and compared the mortality risk and survival time of patients on HDF with patients receiving standard HD in three sets of 2-year cohorts. The primary analyses included the insurance claims data of 460 HDF patients and propensity score-matched 903 standard HD patients who initiated dialysis therapy between 1 April 2012 and 31 March 2018. Patient follow-up was censored at the time of death or the end of the 2-year study period. The number of patients who initiated HDF and the proportion of all-cause mortality cases were evaluated. Additionally, the survival outcomes between propensity score-matched HDF and standard HD patient groups were compared throughout cohorts. The number of HDF patients increased throughout cohorts, but the proportions of mortality cases across cohorts slowly decreased. Adjusting for all study covariates, we observed that HDF patients had a lower mortality risk and longer survival time than patients on standard HD. This study supports the notion that HDF lowers all-cause mortality compared with standard HD in an incident dialysis population in Fukuoka Prefecture, Japan. Full article

Background: Historically, a large gender-related disparity in vascular access (VA) has been demonstrated, with there being a lower prevalence of women with arteriovenous fistula (AVF) compared to men, and women have worse maturity rates. The cause of this difference is not entirely clear, although several reasons that could contribute to it have been hypothesized. The emergence of new percutaneous FAV (pFAV) systems could be an alternative for reducing these differences. Objective: This study aims to determine whether there is a gender difference in the creation of AVFs using new percutaneous systems. Material and Methods: A systematic review of the literature was conducted by searching PubMed and Google Scholar using the following terms: “percutaneous arteriovenous fistula”, “endovascular arteriovenous fistula”, and “hemodialysis”. All clinical trials, comparative studies, and descriptive studies involving patients who underwent a pAVF were included. Results: Finally, the review includes 19 studies, comprising 14 retrospective studies and 5 prospective studies. Of these, six studies are comparative, five of which compare pAVFs with surgically created AVFs (sAVFs), and one compares pAVFs performed using different systems with each other. A total of 1269 patients were included in the review. Of the total number of patients, only 414 were women, representing 32.62% of patients. Conclusions: The number of women included in the various studies analyzing pAVF remains very low, representing less than one-third of all patients. Although the causes of this difference are not entirely clear, several reasons have been hypothesized, such as socioeconomic factors, anatomical factors, or even patients’ preferences. Given these results, further studies are needed to try to clarify the reasons for this gender disparity and to establish different strategies to mitigate the barriers faced by women in accessing AVFs. Full article

Continuous venovenous hemofiltation (CVVH) with citrate anticoagulation has been shown to be associated with substantial losses of calcium and negative calcium balance in ICU patients, which may lead to excessive bone loss and osteoporosis. The aim of this study is to investigate whether plasma parathormone monitoring can identify patients with negative calcium balance during CVVH. This is a retrospective single-center study of all adult ICU patients treated with citrate CVVH from 2021 to 2023. PTH was measured routinely once per week. Calcium excretion in ultrafiltrate fluid and CVVH calcium balance were measured daily. In total, 274 PTH measurements were performed in 111 patients. In 61 measurements (22%), PTH was higher than the upper limit of normal (>8 pmol/L). If PTH was higher than normal, plasma ionized calcium was less than 1.16 mmol/L in 77% of cases and hypercalcemia was never present. In a subgroup of patients treated with CVVH for at least 36 h in the preceding 72 h, PTH values were similar for quartiles by cumulative calcium balance. Increased plasma concentrations of PTH are frequently found in ICU patients treated with citrate CVVH, but no association was found between PTH and the CVVH calcium balance over the last 72 h. Full article

Prof. Dr. George Bakris was an Editorial Board Member of Kidney and Dialysis. His invaluable contributions were instrumental in guiding the journal’s direction and enhancing its success. We are deeply grateful for his unwavering dedication, commitment, and active involvement in the journal’s development. Full article

The Ralstonia species (RB) and Burkholderia species (BB) are bacteria responsible for nosocomial infections in frail patients such as hemodialyzed (HD) patients. Here, we report how we managed an outbreak caused by RB and BB that occurred in a dialysis unit. From the 7th to the 16th of April 2021, an infection due to RB and BB occurred in 7 out of 39 (17.9%) HD patients with central venous catheter (CVC). Disinfectants, CVC-lock therapy solutions, water by reverse osmosis unit (ROW) and dialysis concentrates were cultured, including the biofilm from the loading plastic tubes (LPTs) that connect the hemodialysis consoles (HCs) to the ROW delivery line. The antibiotic treatment was successful for all patients. RB and BB were isolated in the biofilm of 11/37 LPTs. Three out of 11 positive LPTs were associated with the infected patients. The ROW delivery line was modified to provide a whole disinfection with the HCs connected, avoiding the risk of new contamination of the LPTs. A filtration module of 0.01 mm was added prior to the ROW delivery line. Our experience suggests that outbreaks sustained by unusual bacteria such as RB and BB should be promptly investigated to treat the infected patients with the appropriate therapy and to identify the possible source of infection, making the needful changes to achieve a safer dialysis unit. Full article

Apolipoprotein L1 (APOL1) nephropathy results from several podocyte dysfunctions involving morphological and motility changes, mitochondrial perturbations, inflammatory stress, and alterations in cation channel activity. I propose that this phenotype results from increased hydrophobicity of the APOL1 risk variants, which induces two distinct types of podocyte dysfunctions. On one hand, increased hydrophobic interactions with APOL3 cause intracellular variant isoforms to impair both APOL3 control of Golgi PI(4)P kinase-B (PI4KB) activity and APOL3 control of mitochondrial membrane fusion, triggering actomyosin reorganisation together with mitophagy and apoptosis inhibition (hit 1). On the other hand, increased hydrophobic interactions with the podocyte plasma membrane may cause the extracellular variant isoforms to activate toxic Ca²⁺ influx and K⁺ efflux by the TRPC6 and BK channels, respectively (hit 2), presumably due to APOL1-mediated cholesterol clustering in microdomains. I propose that hit 2 depends on low HDL-C/high extracellular APOL1 ratio, such as occurs in cell culture in vitro, or during type I-interferon (IFN-I)-mediated inflammation. Full article

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a complication of cardiopulmonary bypass surgery that frequently occurs in children. The increased availability of pediatric cardiac surgery leads to yearly increases in congenital heart disease (CHD) procedures performed worldwide. The number of complications, including pediatric CSA-AKI, has also increased. Children with CSA-AKI have worse postoperative periods and require more complex post-op intensive care. Thus, the timely commencement of interventions to prevent and to treat kidney injury in CHD children are one of a leading goals of pediatric cardiac intensive care. Full article

It is necessary to ensure adequate energy and protein intake in dialysis patients. However, in addition to the decline in dietary intake in older dialysis patients due to aging, the rate of anorexia is high in dialysis patients, which increases the risk of protein–energy wasting (PEW), sarcopenia, and frailty. There are many causes of anorexia in dialysis patients, including older dialysis patients, and approaches to improve the appetite of such patients have been reported; however, there has been no established approach to improve appetite adequately. Therefore, a key practical goal is to identify anorexia early and implement timely interventions before weight loss occurs. Appetite assessment tools and weight loss assessments are helpful for the screening and early identification of anorectic signs. Nutritional interventions include reducing dietary restrictions, using oral nutritional supplements, and intradialytic parenteral nutrition, as well as replenishing energy, protein, and zinc to prevent the development of nutritional disorders among older dialysis patients. Appetite assessments, early intervention, and dietary and nutritional counseling are key to improving appetite in these patients. The aging rate of dialysis patients in Japan is unprecedented globally, and I believe that this is a situation that will eventually occur in other countries as well. I discuss the factors that contribute to anorexia, especially in older dialysis patients, and Japan’s efforts to address this problem, such as the relaxation of dietary restrictions and the use of oral nutritional supplements. Full article

Background: Limited data exist on postoperative acute kidney injury (AKI) in patients who have undergone esophageal cancer surgery. The purpose of this study was to evaluate the incidence, risk factors, and consequences of postoperative acute kidney after esophagectomy. Methods: This was a retrospective cohort study. The study was conducted in a tertiary specialized cancer center in Italy. All patients undergoing elective esophageal cancer surgery between 2016 and 2021 were included in the study. AKI was defined according to Kidney Disease Improving Global Outcomes criteria (both serum creatinine and urine output), within 48 h after surgery. Preoperative and intraoperative data were registered. We also collected data concerning progression of AKI, need for renal replacement therapy, mortality, and medical (pulmonary, cardiovascular, septic) and surgical complications within 30 days from surgery, as well as length of hospital stay. Results: Incidence of postoperative AKI was 32%. The independent risk factors were body mass index and the use of an invasive surgical approach. Persistent AKI accounted for 15% of the cases and it was associated with increased risk of major cardiovascular events (odds ratio 4.14, 95% CI 1.05–15.8, p-value 0.036), pulmonary complications (OR 3.67, 95% CI 1.04–14.9, p-value 0.050), and increased length of hospital stay (AME 7.2, 0.5–13.9, p-value 0.035). Conclusions: Postoperative AKI is common after esophageal cancer surgery. BMI and a totally invasive surgical approach are independent risk factors. Persistent AKI lasting more than 48 h increased the risk for any cardiovascular or pulmonary complications, with prolonged length of hospital stay. Full article

Leptospirosis is a re-emerging zoonotic disease that has had an unprecedented impact on most health systems in the world. The spectrum of symptoms is variable and usually ranges from asymptomatic cases to severe manifestations involving multiple organ dysfunction accompanied by jaundice, hemorrhage, meningitis, and acute kidney injury that requires the need for intensive care assistance. Although early antibiotic treatment is usually effective, in severe cases, it may require renal replacement therapy, invasive mechanical ventilation, vasoactive support, and invasive hemodynamic monitoring, increasing the risk of death. In Latin America, the real burden of acute kidney injury in this condition is unknown and may be underestimated due to the rapid progression of the disease, similar to other vector zoonoses, and the low coverage of diagnostic tests in primary care, especially in rural regions. Therefore, below, we review the clinical aspects and describe the scientific, clinical, and therapeutic evidence of acute kidney injury attributed to Leptospira spp. and its relevance in patients with severe leptospirosis in Latin America. Full article

Pregnancy in the dialysing population is an infrequent but increasing event. There is a lack of contemporary guidance regarding the nutritional management of this complex patient group. The aim of this scoping review was to identify, evaluate and summarise the evidence base describing nutritional recommendations for pregnant women receiving dialysis. A systematic search strategy of four databases and the grey literature was conducted. Eligible publications contained reference to recommendations regarding nutrition, supplements, breastfeeding, dietary patterns, and/or weight recommendations for pregnant dialysing women. A total of 136 eligible records were included for synthesis including 66 case reports/case series, 46 reviews, 15 book chapters, 5 editorials, and 4 consensus guidelines/position papers. Recommendations regarding energy, protein, dietary patterns, weight, and vitamin and mineral supplementation were common. However, significant discrepancy across these recommendations was evident. There were limited recommendations regarding other nutrients and breastfeeding. A summary of nutritional recommendations to guide clinical practice was constructed. Pregnancy planning, pre-conception dietetic counselling, interprofessional education, and the guidance synthesised in this review could be utilised by clinicians to improve clinical management and optimise outcomes in these patients. Future research should explore the experiences and perspectives of pregnant dialysing women, investigate nutrient losses during intensive dialysis, and evaluate postpartum follow-up. Full article

A perturbation in the water balance rather than any change in salt content is the main cause of hyponatremia, the most frequent electrolyte abnormality, defined as a serum sodium concentration <135 mEq/L. Hyponatremia may be divided between mild (Na > 120 mEq/L) or severe (Na < 120 mEq/L) hyponatremia, and is most frequently observed in elderly ICU hospitalized patients. Based on tonicity, hyponatremia may be hypotonic (a decreased concentration of the solute), isotonic, and hypertonic (falsely low sodium). According to the volume of extracellular fluid (ECF), hyponatremia is further divided among hypovolemic, euvolemic, or hypervolemic hyponatremia. Finally, hyponatremia may develop rapidly as acute (<48 h), usually with severe symptoms, or slowly as chronic hyponatremia, usually being asymptomatic or with mild symptoms. Acute severe hyponatremia presents with severe CNS problems, increased hospitalization rates, and mortality. The treatment with 3% sodium chloride and a 100 mL IV bolus based on severity and persistence of symptoms needs careful monitoring. A non-severe hyponatremia may be treated with oral urea. In asymptomatic mild hyponatremia, an adequate solute intake with an initial fluid restriction of 500 mL/d adjusted according to the serum sodium levels is preferred. Vaptans could be considered in patients with high ADH activity regardless of whether they are euvolemic or hypervolemic. In general, the treatment of hyponatremia should be based on the underlying cause, the duration and degree of hyponatremia, the observed symptoms, and volume status of patient. Full article

Conventional hemodialysis (HD) (a 4 h session three times a week) is not appropriate for everyone and is excessive in the presence of substantial residual kidney function (RKF). However, it can be safely replaced by a softer incremental approach guided by the urea kinetic model (UKM), starting with one or two sessions a week. Observational data suggest that RKF may be lost less quickly if dialysis is initiated less frequently than 3 times a week. Incremental HD means that, in the presence of substantial RKF, kidney replacement therapy can begin with low doses and/or frequencies, which, however, must be adequately increased to compensate for any subsequent losses of RKF, keeping the total clearance level (kidney + dialysis) always above the minimum levels of adequacy. In HD, there are complexities in combining the dialysis dose with RKF, but tools have been developed to facilitate this issue. The literature findings lend support to the safety of incremental HD and highlight the potential for this method to be implemented as a new standard of care in dialysis patients with substantial RKF. Ongoing and future trials will likely generate further evidence of the clinical and healthcare benefits of incremental HD in routine practice. Full article

Urgent-start peritoneal dialysis (USPD) is defined as peritoneal dialysis initiated within 14 days of catheter insertion. In this review, the authors describe the most recent data on USPD, including outcomes, complications, barriers to implementation, and areas for future research. Outcomes appear similar between catheter insertion techniques, so patient factors and institutional workflow should guide practice. Mechanical complications may occur at a higher rate in USPD, but it does not impact technique survival or mortality. Infectious complications appear unchanged in USPD, and there may be fewer complications compared to urgent-start hemodialysis. Barriers to implementation are multifactorial, including physician and staff unfamiliarity and lack of institutional support. A significant limitation within the field includes lack of uniform terminology and definitions. Full article

Magnesium is an essential element with a pleiotropic role in human biology. Despite tight intestinal and renal regulation of its balance, insufficient intake can finally result in hypomagnesemia, which is a proxy of intracellular deficiency. Conditions such as diabetes, cancer, and infections are often associated with hypomagnesemia, which mostly predicts an unfavorable outcome. The effects of hypomagnesemia can either be direct and include neurological and cardiovascular symptoms or indirect, taking a mechanistic role in inflammation, endothelial dysfunction, and oxidative stress. The indication for intravenous magnesium as a treatment of torsades de pointes and pre-eclampsia is unrefuted, but new indications of peroral or intravenous supplementation, albeit with less supporting evidence, have emerged suggesting, respectively, an attenuation of vascular calcification in chronic kidney disease and improved rate control in atrial fibrillation. Other potential beneficial properties of magnesium, which were claimed by observational data, such as lipid lowering and renal protection, were not, or only partially, investigated in randomized controlled trials. Thus, the role of peroral supplementation of mild chronic asymptomatic hypomagnesemia should be separated from the more targeted prescription of magnesium in specific study populations. (Severe) hypermagnesemia is potentially life-threatening and occurs almost uniformly in subjects with severe renal failure exposed to either supplements or to magnesium-containing cathartics or antacids. Moderate hypermagnesemia is very common in pre-eclamptic women treated with intravenous magnesium. For most (but not all) studied endpoints, mild hypermagnesemia yields a survival benefit. Long-lasting concerns about the potential negative effects of mild hypermagnesemia on bone physiology and structure have so far not been unequivocally demonstrated to be troublesome. Full article

Nephrotic syndrome (NS) is a complex clinical entity characterized by proteinuria, hypoalbuminemia, and edema. In this review, we propose the view of NS as a podocytopathy, highlighting the importance of understanding the role of podocytes in the development of this condition. We discuss the various etiologies of NS, ranging from congenital to primary renal diseases, as well as secondary forms due to systemic diseases. We also delve into the mechanisms underlying podocyte injury, which plays a crucial role in the development of NS. By viewing NS as a podocytopathy, we suggest potential implications for the diagnosis and treatment of this condition, including the use of podocyte-specific biomarkers and targeted therapies. Our review provides a comprehensive overview of NS and its underlying mechanisms, emphasizing the importance of a multidisciplinary approach to the diagnosis and management of this condition. Further research is essential to better understand the complex interplay between podocyte injury and the development of NS, with the ultimate goal of improving patient outcomes. Full article