Optical dialysis adequacy sensor: wavelength dependence of the ultra violet absorbance in the spent dialysate to the removed solutes

Abstract

A need for dialysate-based, on-line, continuous monitoring systems for the control of dialysis efficiency and the prevention of dialysis-associated complications is arisen due to increasing number of dialysis patients and related treatment quality requirements. The aim of this study was to investigate the wavelength dependence between the the ultra-violet (UV) absorbance in the spent dialysate and the retained solutes removed during the hemodialysis in order to explain possibilities to estimate removal of the solutes by the optical dialysis adequacy sensor. Ten uremic patients, during 30 hemodialysis treatments, were followed at the Department of Dialysis and Nephrology, North-Estonian Regional Hospital. The dialysate samples were taken and analyzed with spectrophotometer to get absorbance spectra. The results confirm previous studies considering similarity for the UV-spectrum on the spent dialysate samples during a single dialysis session indicating presence of the same type of chromophores in the spent dialysate removed from the patient's blood for different patients groups. At the same time the highest correlation in the spent dialysate for urea, creatinine, potassium, and phosphate was obtained at the wavelength 237 nm that is a new finding compared to earlier results. The highest correlation between the UV-absorbance and uric acid in the spent dialysate was obtained at the wavelength 294 nm. Presence of at least two different wavelength ranges may add selectivity for monitoring several compounds. Our study indicates that the technique has a potential to estimate the removal of retained substances.

Theoretical Study of Uric Acid and its Ions in Aqueous Solution

“…There have been many measurements of the UV absorption spectra of uric acid and its anions in aqueous solution, some with specific pH controlled by buffers and some without specified pH values [37,[42][43][44][45][46][47][48][49][50][51][52]. In Supplementary table, we summarize the measurements in order to assess the reliability of calculated vertical excitation energies and present the midrange value for each transition, after rejecting some likely outliers, indicated in italics.…”

Notice of Violation of IEEE Publication Principles: Computational Model of Protein-Bound Uremic Toxins Kinetics During Hemodialysis and Dose Evaluation of Accurate Dialysis Using Deep Learning Techniques

“…In [16] authors reported a method for investigating the wavelength dependency between the ultraviolet (UV) absorbance in the spent dialysate and the remaining dissolved salts extracted during hemodialysis to clarify possibility for estimating the optical dialysis suitability sensor for elimination of the dissolved salts. In the North-Estonian Regional Hospital's Department of Dialysis and Urology, 10 uremic patients are diagnosed with 30 hemodialysis therapies.…”

Theoretical Study of Uric Acid and its Ions in Aqueous Solution

“…There have been many measurements of the UV absorption spectra of uric acid and its anions in aqueous solution, some with specific pH controlled by buffers and some without specified pH values [37,[42][43][44][45][46][47][48][49][50][51][52]. In Supplementary table, we summarize the measurements in order to assess the reliability of calculated vertical excitation energies and present the midrange value for each transition, after rejecting some likely outliers, indicated in italics.…”