This week in Nephrology

Welcome to This Week in Nephrology. This week we're covering 10 notable papers spanning cardiovascular risk in the dialysis population, drug and infection safety across dialysis and hospital care, and a cluster of consensus and implementation documents that tell us where the field's biggest delivery gaps sit. Let's dive in.

We'll start with the heart on dialysis, because two papers in the Clinical Journal of the American Society of Nephrology approach the same problem from opposite ends. Charytan and colleagues offer a state-of-the-art review of intradialytic myocardial stunning, proposing a working definition for this entity and making the case that the transient contractile dysfunction seen during a dialysis session is best understood as a form of stress, or Tako-tsubo, cardiomyopathy rather than simple demand ischaemia [5]. The clinical argument is that these repetitive insults, three times a week for years, plausibly contribute to the extraordinary cardiovascular event rate in this population, and that we currently have no agreed diagnostic threshold, no routine screening pathway, and no proven intervention. That is a research agenda more than a practice change, but it should shift how you interpret a session complicated by hypotension. Alongside it, Hsieh and colleagues report a prospective multicentre cohort of 1,136 maintenance haemodialysis patients across 12 centres, using roughly 36 pre-dialysis readings per patient over a standardised twelve-week baseline to quantify visit-to-visit blood pressure variability [6]. Over a median follow-up of about four and a half years, 144 patients had an ischaemic stroke, and each ten percent increment in systolic variability was associated with roughly a seventy percent higher stroke risk after adjustment for mean blood pressure, comorbidities, medications and dialysis factors. The association was most consistent for large artery atherosclerotic stroke, and diastolic variability showed no significant independent association. The practical message is that the pattern of your patient's pre-dialysis readings carries information that the average does not, and a highly erratic chart deserves attention rather than reassurance.

The second theme is safety — infections and medications — and here three papers converge on the idea that risk is far more granular than our current frameworks assume. In Kidney360, Fuller and colleagues analysed Medicare claims linked to United States Renal Data System records from 2016 through 2023 and documented something uncomfortable: central venous catheter use in the dialysis population rose from about sixteen percent to about twenty-four percent across the pandemic period [8]. Staphylococcus aureus-related sepsis occurred at 3.3 first events per 100 patient-years overall, but that figure conceals a wide gradient — 8.4 per 100 patient-years among haemodialysis patients with catheters, compared with 2.0 with arteriovenous fistulas and just 1.0 among peritoneal dialysis recipients. In adjusted models, catheter use versus a fistula was associated with roughly a four-fold higher hazard. Rates were also higher in younger patients, in men, and in those with diabetes, heart failure or immunosuppression. Given the post-pandemic drift back toward catheters, this is a reminder that access planning is infection prevention. Turning to peritoneal dialysis, Fan and colleagues in Kidney International Reports used Hong Kong electronic health records from 2006 to 2019 in a target trial emulation involving 11,693 patients and over 240,000 person-trials, specifically designed to avoid immortal time bias [7]. Starting a proton pump inhibitor, compared with not starting acid suppression, was associated with about a fifty percent higher risk of peritonitis, roughly a fifty-five percent higher all-cause mortality, and a significant increase in peritonitis-related death. Histamine-2 receptor antagonists carried a smaller but still elevated peritonitis risk, around twenty percent higher. In the head-to-head comparison there was no significant difference in peritonitis between the two drug classes, but proton pump inhibitors were associated with higher all-cause and peritonitis-related mortality than the antagonists. Risk elevations were most pronounced in patients with higher baseline risk. This is observational and confounding by indication is the obvious concern, but for a drug class that is so often continued without a current indication, it strengthens the case for a deliberate review of every acid suppressant on a peritoneal dialysis medication list. The third safety paper, also in Kidney360, challenges how we label nephrotoxins at all. Wang and colleagues studied nearly 67,000 admissions at a single United States academic centre in which patients received at least three concurrent potentially nephrotoxic medications, and stage 2 or 3 acute kidney injury developed within seven days in about five percent [4]. Rather than a uniform hazard, adjusted associations varied widely by class: piperacillin-tazobactam was associated with roughly seventy percent higher odds of severe acute kidney injury, while non-steroidal anti-inflammatory exposure in this already high-risk population was associated with lower odds — a counterintuitive finding that likely reflects who gets prescribed them. Of 66 two-way class interactions tested, nine remained significant after correction, and adding class and pairwise terms improved model discrimination only modestly. The take-home is that simply counting nephrotoxins, as most electronic surveillance systems do, is a crude instrument; weighting by class and combination is the logical next step.

Our third theme is guidance and implementation, and this week brought four documents worth knowing about. Kidney International published the report of a KDIGO implementation summit held in Kuala Lumpur in 2024, which brought together nephrologists, endocrinologists, primary care physicians, dietitians, a health economist and patient partners from 13 Asia-Pacific countries and regions to ask why the diabetes-in-chronic-kidney-disease and blood-pressure guidelines are not reaching patients [1]. The barriers clustered around lifestyle intervention, building team-based integrated care, achieving treatment targets and doing albuminuria screening, and actually delivering guideline-directed medical therapy — with solutions deliberately stratified by country income level. Also in Kidney International, Nester and colleagues report the SEISMIC summit from July 2025 on C3 glomerulopathy and primary immune complex membranoproliferative glomerulonephritis [2]. With iptacopan approved for C3 glomerulopathy and pegcetacoplan for the broader spectrum, the field has moved from having nothing to having disease-modifying complement inhibitors — and the summit's focus was squarely on the diagnostic delays and access barriers that will otherwise keep these drugs from the ultra-rare patients who need them. If you have such a patient, expect biopsy interpretation and payer navigation to be your rate-limiting steps. Meanwhile, in Kidney International Reports, an international group of eight nephrologists and three dietitians led by Wang produced 20 consensus statements and 34 practice points on nutritional supplementation in dialysis, using a formal European Society for Clinical Nutrition and Metabolism consensus method [3]. The structure they recommend is worth adopting: screen and reassess every patient routinely, build oral nutritional support around patient preference with renal-specific formulas where needed, and reserve intradialytic parenteral nutrition for selected patients with protein-energy wasting, either supplementing the oral diet or combined with oral supplements. And in Kidney360, Lucena and colleagues review the water and dialysate purity requirements for high-volume post-dilution haemodiafiltration, defined by a convection volume of at least 23 litres per session, as interest grows in the United States [10]. Their point is infrastructural: the survival and haemodynamic benefits depend on delivered convective dose, and delivering that dose safely requires validated multistage water treatment, ultrapure dialysate, structured microbiological surveillance and endotoxin-retentive filtration — with the caveat that some United States regulatory references still point to older standards than the current international consensus.

Finally, one randomised trial. In Kidney International Reports, Smith and colleagues report ORCHARD-BEET, an eight-centre feasibility trial in the United Kingdom randomising 108 pregnant women with stage G2 to G5 chronic kidney disease before 25 weeks' gestation to standard care or daily beetroot juice providing 400 milligrams of dietary nitrate [9]. This was powered for feasibility, not efficacy, and the primary outcome — recruitment of about one participant per site per month — was met. The clinical signals are hypothesis-generating only: postpartum creatinine trended lower with nitrate among women with lower pre-pregnancy kidney function, and neonatal unit admission trended lower, but neither difference reached statistical significance. Two findings did: serious adverse events occurred in about a quarter of women on dietary nitrate compared with about half on standard care, and in a post hoc analysis fewer women in the nitrate arm required antihypertensive medication during pregnancy. The authors are appropriately clear that a properly powered trial is needed before anyone recommends this.

If you only have time for one paper this week, make it the Hong Kong target trial emulation on gastric acid suppressants in peritoneal dialysis [7]. It targets a medication class that sits, often unreviewed, on a large fraction of peritoneal dialysis medication lists, and it gives you an immediately actionable reason to reassess whether that indication still holds.

Here are the key takeaways from this week in Nephrology. First, in peritoneal dialysis, proton pump inhibitors and to a lesser extent histamine-2 blockers were associated with more peritonitis and higher mortality — review every acid suppressant for a current indication. Second, catheter prevalence in the United States dialysis population has climbed since 2016, and catheters carry roughly four times the Staphylococcus aureus sepsis hazard of a fistula, so access conversion remains the single highest-yield infection prevention move. Third, erratic pre-dialysis systolic blood pressure independently predicts ischaemic stroke, especially large-artery stroke, beyond the mean — look at the pattern, not just the average. Fourth, nephrotoxicity is not binary; piperacillin-tazobactam stood out among classes, and combination effects matter, so weighted rather than simple-count surveillance is where alerting should go. And fifth, new consensus documents this week give you practical scaffolding for dialysis nutrition, for accessing complement inhibitors in C3 glomerulopathy, and for the water quality standards that high-volume haemodiafiltration will demand.

That's your roundup for This Week in Nephrology. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.

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This is an automated summary generated by artificial intelligence, which can make mistakes. Always review the original source materials.