Routine online assessment of dialysis dose: Ionic dialysance or UV-absorbance monitoring?

Intradialytic techniques for automatic and everyday access monitoring

Vascular access dysfunction is associated with reduced delivery of dialysis, unplanned admissions, patient symptoms, and loss of access, making assessment of vascular access a fundamental part of routine care in dialysis. Clinical trials to predict the risk of access thrombosis based on accepted reference methods of access performance have been disappointing. Reference methods are time-consuming, affect the delivery of dialysis, and therefore cannot repeatedly be used with every dialysis session. There is now a new focus on data continuously and regularly collected with every dialysis treatment, directly or indirectly associated with access function, and without interrupting or affecting the delivered dose of dialysis. This narrative review will focus on techniques that can be used continuously or intermittently during dialysis, taking advantage of methods integrated into the dialysis machine and which do not affect the delivery of dialysis. Examples include extracorporeal blood flow, dynamic line pressures, effective clearance, dose of delivered dialysis, and recirculation which are all routinely measured on most modern dialysis machines. Integrated information collected throughout every dialysis session and analyzed by expert systems and machine learning has the potential to improve the identification of accesses at risk of thrombosis.

Comparison of intradialytic continuous and interval training on hemodynamics and dialysis adequacy: A crossover randomized controlled trial

AIM

Circulating blood volume (BV) during exercise changes depending on the intensity and duration, and post-exercise hypotension is observed after continuous exercise. We investigated the safety and efficacy of both interval and continuous IDE at anaerobic threshold (AT) levels with respect to hemodynamic stability and dialysis efficiency.

METHODS

In this crossover randomized controlled trial, 16 patients on haemodialysis were subjected to three trial arms, including non-IDE, interval-IDE, and continuous-IDE arms. Systolic blood pressure (SBP), BV, and ultraviolet absorbance - an indicator of dialysis efficiency - were continuously measured, and each change was compared between the three arms by two-way analysis of variance.

RESULTS

Continuous IDE decreased SBP from post-exercise to the end of dialysis compared with baseline (pre 142.8 ± 19.0 vs. post 127.5 ± 24.5 mmHg, p = .02), whereas interval IDE maintained better SBP levels post-exercise (pre 139.9 ± 17.1 vs. post 140.1 ± 15.8 mmHg, p = 1.0) than continuous IDE (non-IDE 133.2 ± 19.9 vs. interval 140.1 ± 15.8 vs. continuous 127.5 ± 24.5 mmHg, p = .04). Moreover, interval IDE caused less tiredness and few symptoms (p < .05), despite reaching higher intensity than continuous IDE (p = .001). The BV of each IDE arm decreased during exercise and recovered post-exercise to the same level as non-IDE. Ultraviolet absorbance was not different between each arm (p = .16).

CONCLUSION

AT-level interval IDE maintains better hemodynamic stability from post-exercise to the end of dialysis and may represent a novel approach that can be effectively performed with fewer symptoms.

Optical monitoring of hemodialysis using noninvasive measurement of uric acid in the dialysate

The aim of this study was to present a methodology for predicting changes in uric acid concentrations in the blood of chronically hemodialyzed patients based on an optical measurement of the intensity of selected wavelengths in the dialysate. Blood samples were taken from the arterial line every 30 min throughout the hemodialysis period, to measure uric acid levels. Simultaneously, optical measurements were made on dialysate flowing from the dialyzer. Uric acid concentration can be measured either directly from the blood or from dialyzer outflow with acceptable error. In addition, both methods reveal any increased dynamics in uric acid concentration in the initial phase of hemodialysis. The wavelength of the light was adjusted for optimal uric acid particle detection. Comparing the uric acid concentration measured in the blood of patients with the intensity of wave absorption in the dialysate, the functional relationship between the uric acid concentration levels was determined. Using the optical method for measuring uric acid concentration in the dialysate, the concentration of uric acid in the blood during hemodialysis can be non-invasively and accurately estimated. This method can be used to assess the adequacy of hemodialysis by computer acquisition of uric acid concentrations determined in on-line dialysate.