High-volume post-dilution hemodiafiltration (HVHDF), defined by a convection volume ≥23 L/session, is associated with improved survival and clinical outcomes compared with conventional high-flux hemodialysis. Because HVHDF requires infusion of large volumes of sterile substitution fluid, treatment safety depends on rigorous control of dialysis water and fluid purity. With expanding interest in the United States, guidance on quality standards and implementation is needed. We conducted a narrative review of current evidence and technical standards governing dialysis water, dialysate, and online-produced substitution fluid. International quality frameworks, including the ISO 23500 series and ANSI/AAMI standards, were examined alongside principles of system validation, microbiological surveillance, and risk management relevant to U.S. clinical practice. Emerging technologies for rapid microbial detection and resource optimization were also evaluated. HVHDF consistently achieves greater small- and middle-molecule clearance, reduced inflammatory markers, improved hemodynamic stability, and favorable clinical outcomes, with benefit closely related to delivered convective dose. Safe implementation requires validated multistage water treatment systems capable of consistently meeting ANSI/AAMI RD52 chemical and microbial standards, while dialysis machines ensure production of ultrapure dialysate and sterile, nonpyrogenic substitution fluid through integrated ultrafiltration safeguards. Structured surveillance programs, bacteria- and endotoxin-retentive filtration, and adherence to defined chemical and microbiological thresholds are essential. Although international standards have largely converged, certain U.S. regulatory references continue to reflect earlier AAMI documents. Technological innovations, including high-efficiency reverse osmosis, automated dialysate flow adjustment, and controlled ultrafiltration, enable delivery of high convective volumes while containing water and energy use. Dialysis water and fluid purity are foundational to safe, scalable HVHDF. In the evolving U.S. landscape, integration of validated water systems, structured surveillance, and technology-supported prescription optimization is essential to realize the clinical and sustainability potential of online HDF.
Rationale & Objective: Preservation and maintenance of a complication-free arteriovenous fistula (AVF) remains significant challenge. An adequate cannulation technique and successful puncture are critical for preserving AVF and ensuring patient safety. The study investigated whether the multiple single cannulation technique (MuST) leads to improved AVF survival and a lower complication rate than the rope-ladder (RL) technique. Study Design: The MuST study was a multicenter, prospective, nonblinded, parallel group, randomized controlled trial. Setting & Participants: A total of 101 patients received hemodialysis in 3 peripheral units; 49 patients were assigned to the MuST group and 52 to the control group. Intervention: The intervention group received MuST, whereas the control group underwent the RL technique, with both groups followed for period of 12 months. Outcomes: The primary outcome was to evaluate the AVF survival rate at 12 months, defined as unassisted patency. The secondary outcome included the assessment of assisted primary patency, complication rates, and pain perception.Results: There were no statistically significant differences between the MuST and RL techniques in unassisted patency (HR, 1.02; 95% CI, 0.38-2.71; P = 0.98) or in assisted patency (HR, 0.74; 95% CI, 0.37-1.47; P = 0.39). There were no statistically significant differences in the incidence of hematoma or thrombosis, and no infections occurred during the study period. The MuST presented an advantage over the RL technique in the development and formation of new aneurysms. There were no significant differences observed in pain perception between the 2 cannulation techniques. Limitations: The sample size was smaller than expected due to limitations in the selection of patients during the SARS-CoV-2 pandemic phase. Conclusions: We could not definitively demonstrate a difference in AVF survival between MuST and RL. The low incidence of AVF thrombosis in both techniques shows that MuST can be a choice for patient safety and well-being when nursing teams decide which cannulation technique to perform. Trial Registration: Registered at ClinicalTrials.gov with identifier NCT05081648.
BACKGROUND:The arteriovenous fistula (AVF) is the preferred vascular access for patients undergoing hemodialysis, and early identification of complications such as stenosis or dysfunction is essential to preserve access patency and reduce morbidity. METHOD:AVF bruit recordings were collected from 65 patients across 12 dialysis centers in Europe and Asia using a digital stethoscope connected to the medical record of the patients. A deep learning model was developed to detect high-pitched bruits-an acoustic marker commonly associated with AVF stenosis. Expert-annotated recordings served as the reference standard for supervised training and evaluation. RESULTS:Mean age of patients was 68, and the average blood flow during the dialysis session was 352 ml/min. The model demonstrated excellent performance on independent testing datasets, achieving a sensitivity of 97.1%, specificity of 73.8%, and an overall accuracy of 82%. The area under the receiver operating characteristic curve (ROC-AUC) was 94%, reflecting strong discriminative ability. The model showed excellent calibration. Model performance across different experimental retraining folds indicates a stable and reliable training process. CONCLUSION:The integration of this deep learning tool into clinical workflows could provide clinicians with a sensitive, objective, and time-efficient method for detecting high-pitched bruits which may be used in combination with other clinical signs for the detection of AVF complications such as stenosis. Implemented through a low-cost phono angiography protocol requiring minimal training, this approach has the potential to support earlier interventions and improve outcomes in the hemodialysis population.
Introduction: The relationship between hemodialysis treatment time, hospitalization rates, and mortality remains an area of controversy because of difficulties in separating the clinical effects of treatment time from urea clearance and ultrafiltration (UF) volume. Methods: Data were obtained from a retrospective cohort of 146,127 maintenance in-center hemodialysis patients, aged 18 to 89 years, who dialyzed at Fresenius Kidney Care (FKC) clinics between January 1, 2022 and July 1, 2023 with 1-yearfollow-up after a 30-day run-in period. The patients were stratified into 6 treatment-time groups based on their mean delivered treatment time during the exposure period (180-194, 195-209, 210-224, 225-239, 240-254, and 255-269 minutes). The primary outcome was all-cause mortality; secondary outcomes included all-cause hospitalization rates and hospital length of stay. Results: Mean dialysis vintage was > 4 years, and few patients likely had residual kidney function. Compared with individuals in the 180-194 minutes group, patients in the 240-254 minutes group had a 27% lower mortality (hazard ratio: 0.73 [0.69-0.76]), whereas patients in the 210-224 minutes and 225-239 minutes groups both had a 19% lower mortality (hazard ratio: 0.81 [0.77-0.85]) and 195-209 minutes group had 15%. These benefits were observed in patient subgroups across a wide range of mean UF volumes as well as with a spKt/V > 1.4, but not for patients with spKt/V < 1.4. In secondary analyses, similar associations were observed between longer treatment times (up to 240-254 minutes) and reduced hospitalization rates and shorter hospital stays. Conclusion: Longer dialysis treatment times are associated with better survival, fewer hospitalizations, and shorter hospital stays. Although the potential for selection bias cannot be excluded, these survival benefits were realized even when accounting for UF volume and spKt/V > 1.4.
