Modifiable Factors Associated with Achievement of High-Volume Post-Dilution Hemodiafiltration: Results from An International Study

Abstract

Dialysis center policy in terms of blood flow, treatment time, filter size, and perhaps even hemoglobin targets plays a key role in achieving high-volume HDF. All of these are modifiable factors that can help in prescribing an optimal combination of dialyzer size, achievable blood flows, and treatment times.

Dialysis and Patient Factors Which Determine Convective Volume Exchange in Patients Treated by Postdilution Online Hemodiafiltration

“…Standardized b expresses how much substitution volume changes when that independent variable changes by 1 SD and thus it conveys the relative importance of the different variables. Most other studies have used a constant dialysate flow, not analyzed the effect, or used much slower dialysate flows than used in our patient cohort (11,23,26). However, we also observed that individual parameters, such as lower serum albumin, higher CRP, greater anticoagulation dose requirement, diabetes, and overall comorbidity resulted in lower substitution volume exchanged.…”

“…As patients usually have greater weight gains with the longer weekend gap between dialysis sessions, and, therefore, greater ultrafiltration requirements, this may explain previous reports of lower convective exchanges with the first OL-HDF session of the week compared to the last session, in terms of less substitution fluid, but more ultrafiltration (23). As such some previous studies have reported a reduction in convective exchange with increasing hematocrit (11,26). Convection is driven by hydrostatic pressure and as such is dependent upon blood flow.…”

“…However, we also observed that individual parameters, such as lower serum albumin, higher CRP, greater anticoagulation dose requirement, diabetes, and overall comorbidity resulted in lower substitution volume exchanged. Previous reports of convection volume achieved with postdilutional online hemodiafiltration have commented on serum albumin being associated with greater convective volumes (11,23), or no effect (26). As patients usually have greater weight gains with the longer weekend gap between dialysis sessions, and, therefore, greater ultrafiltration requirements, this may explain previous reports of lower convective exchanges with the first OL-HDF session of the week compared to the last session, in terms of less substitution fluid, but more ultrafiltration (23).…”

“…b reflects the change of the total substitution volume (in liters per treatment) related with 1 unit increment of the variable. However there are reports of reduced convective exchanges with higher BMI and male sex, although in this study session time was fixed to a minimum of 4 h (26). Model fit r 2 5 0.56, adjusted r 2 5 0.55 dialysis parameters, including session time, blood flow rate, and dialysate temperature and flow rate.…”

Effectiveness of a New Single‐Needle Single‐Pump Dialysis System with Simultaneous Monitoring of Dialysis Dose

“…), others mainly defined by patient characteristics , that is, extracorporeal blood flow. Blood flow is one of the most important factors associated with adequacy not only in terms of low‐molecular weight substances for achieving Kt / V ( K ‐ dialyzer clearance of urea; t ‐ dialysis time; V ‐ volume of distribution of urea) but also of middle molecule clearances as it is also a driver for convective volume in postdilution hemodiafiltration.…”