Background and objectives High‐volume online hemodiafiltration (OL‐HDF) associates with improved outcomes compared to hemodialysis (HD), provided adequate dosing is achieved as estimated from convective volume (CV). Achievement of high CV and its impact on biochemical indicators following a standardized protocol converting HD patients to OL‐HDF has not been systematically reported. We assessed the success of implementation of OL‐HDF in clinics naïve to the modality. Design, setting, participants, and measurements We analyzed the results of the implementation of postdilution OL‐HDF in patients randomized to the HDF arm of a clinical trial (impact of hemoDiaFIlTration on physical activity and self‐reported outcomes: a randomized controlled trial (HDFit) trial [http://clinicaltrials.gov:NCT02787161]). The day before randomization of the first patient to OL‐HDF at each clinic staff started a 3‐day in‐person training module on operation of Fresenius 5008 CorDiax machine in HDF mode. Patients were converted from high‐flux HD to OL‐HDF under oversight of trainers. OL‐HDF was performed over a 6‐months follow‐up with a CV target of 22 L/treatment. We characterized median achieved CV >22 L/treatment record and analyzed the impact of HDF on biochemical variables. Results Ninety‐seven patients (mean age 53 ± 16 years, 29% with diabetes, and 11% had a catheter) from 13 clinics randomized to the OL‐HDF arm of the trial were converted from HD to HDF. Median CV > 22 L/treatment was achieved in 99% (94/95) of OL‐HDF patients throughout follow‐up. Monthly mean CV ranged from 27.1 L to 27.5 L. OL‐HDF provided an increased single pool Kt/V at 3‐months (0.2 [95% CI: 0.1–0.3]) and 6‐months (0.2 [95% CI: 0.1–0.4]) compared to baseline, and reduced phosphate at 3‐months (−0.4 mg/dL [95% CI: −0.8 to −0.12]) of follow‐up. Conclusions High‐volume online hemodiafiltration was successfully implemented with 99% of patients achieving protocol defined CV target. Monthly mean CV was consistently >22 L/treatment during follow‐up. Kt/V increased, and phosphate decreased with OL‐HDF. Findings resulting from a short training period in several dialysis facilities appear to suggest HDF is an easily implementable technique.

BackgroundEnd stage renal disease (ESRD) patients require a renal replacement therapy (RRT) to filter accumulated toxins and remove excess water, which are associated with impaired physical function. Hemodialysis (HD) removes middle-molecular weight (MMW) toxins less efficiently compared to hemodiafiltration (HDF); we hypothesized HDF may improve physical function. We detailed the design and methodology of the HDFIT protocol that is testing whether changing from HD to HDF effects physical activity levels and various outcomes.MethodsHDFIT is a prospective, multi-center, unblinded, randomized control trial (RCT) investigating the impact of dialysis modality (HDF verses HD) on objectively measured physical activity levels, self-reported quality of life, and clinical/non-clinical outcomes. Clinically stable patients with HD vintage of 3 to 24 months without any severe limitation ambulation were recruited from sites throughout southern Brazil. Eligible patients were randomized in a 1:1 ratio to either: 1) be treated with high volume online HDF for 6 months, or 2) continue being treated with high-flux HD. This study includes run-in and randomization visits (baseline), 3- and 6-month study visits during the interventional period, and a 12-month observational follow up. The primary outcome is the difference in the change in steps per 24 h on dialysis days from baseline to the 6-month follow up in patients treated with HDF versus HD. Physical activity is being measured over one week at study visits with the ActiGraph (www.actigraphcorp.com). For assessment of peridialytic differences during the dialysis recovery period, we will analyze granular physical activity levels based on the initiation time of HD on dialysis days, or concurrent times on non-dialysis days and the long interdialytic day.DiscussionIn this manuscript, we provide detailed information about the HDFIT study design and methodology. This trial will provide novel insights into peridialytic profiles of physical activity and various self-reported, clinical and laboratory outcomes in ESRD patients treated by high volume online HDF versus high-flux HD. Ultimately, this investigation will elucidate whether HDF is associated with patients having better vitality and quality of life, and less negative outcomes as compared to HD.Trial registrationRegistered on ClinicalTrials.gov on 20 April 2016 (NCT02787161).Electronic supplementary materialThe online version of this article (10.1186/s12882-019-1247-8) contains supplementary material, which is available to authorized users.