Interventions to improve hemodialysis adequacy: protocols based on real-time monitoring of dialysate solute clearance

Abstract

BackgroundThe monitoring of dialysate ultraviolet (UV) absorbance is a validated technology to measure hemodialysis adequacy and allows for continuous and real-time tracking every session as opposed to the typical once-monthly assessments. Clinical care guidelines are needed to interpret the findings so as to troubleshoot problematic absorbance patterns and intervene during an individual treatment as needed.MethodsWhen paired with highly structured clinical care protocols that allow autonomous nursing actions, this technology has the potential to improve treatment outcomes. These devices measure the UV absorbance of dialysate solutes to calculate and then display the delivered as well as predicted clearance for that session. Various technical factors can affect the course of dialysate absorbance, confound the device’s readout of clearance results and thus lead to challenges for the dialysis unit staff to properly monitor dialysis adequacy. We analyze optimal and problematic patterns to the device’s ‘clearance’ display (e.g. due to thrombosis of hollow fibers, inadequate access blood flow or recirculation) and provide specific interventions to ensure delivery of an adequate dialysis dose. A rigorous algorithm is presented with representative device monitor display profiles from actual hemodialysis sessions. Procedural rationale and interventions are described for each individual scenario.ConclusionReal-time hemodialysate UV absorbance patterns can be used for protocol-based intradialytic interventions to optimize solute clearance.

Adequacy of hemodialysis in acute kidney injury: Real‐time monitoring of dialysate ultraviolet absorbance vs. blood‐based Kt/Vurea

“…Acutely ill patients with AKI have variable intradialytic urea generation and ultrafiltration volumes due to cardiovascular instability, sepsis, volume resuscitation, and other factors. Furthermore, hemodynamic and volume changes during dialysis sessions including fluctuations in blood pressure, administration of supportive albumin and others may further contribute to an inaccurate estimation of the dialysis dose through blood‐based methods 16 . Despite these drawbacks, blood‐based spKt/Vurea is recommended to track adequacy of IHD in patients with AKI by KDIGO and KDOQI 4 …”

“…Dialysis machines that incorporate urea sensors and monitor urea clearance via UV absorbance technology offer a continuous measurement of solutes in the effluent which decrease in concentration over the treatment time. Although decay curves were not evaluated in this study, previous reports have described some of the benefits of monitoring dialysis adequacy by calculating the target UV‐Kt/V and the delivered Kt/V in different points during the prescribed time 16 . The prescriber and user can discern how the achieved clearance varies from the target trajectory and predict whether the patient will reach the adequacy goal.…”

“…The patient's pre‐dialysis weight was entered by the nurse prior to start of dialysis and this is used by the machine to calculate the Kt/Vurea. While the machine measures absorbance, it graphically displays the calculated clearance which increases during dialysis 16 . The accuracy of the UV sensor has been previously validated in ESKD patients by Castellarnau and colleagues 14 .…”

Improved outpatient haemodialysis adequacy using queued schedules

“…Although we attempted to exclude patients with unstable medical conditions or problematic vascular access, we cannot exclude those technical factors that could have confounded treatment clearance; however, we believe this was minimised by real-time troubleshooting of problematic treatments by the routine use of ultraviolet light absorbance dialysate-based clearance-monitoring technology, as we have previously reported (Ross et al 2018).…”

Adequacy of Dialysis in Iranian Patients Undergoing Hemodialysis: A Systematic Review and Meta-Analysis

“…modeling (Kt/V) are used to evaluate the adequacy of dialysis (12). The urea kinetic modeling represents a fractional volume cleared of urea per dialysis.…”