| 1. |
- Adoberg, Annika, et al.
(författare)
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Treatment with Paracetamol Can Interfere with the Intradialytic Optical Estimation in Spent Dialysate of Uric Acid but Not of Indoxyl Sulfate
- 2022
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Ingår i: Toxins. - : MDPI. - 2072-6651. ; 14:9
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Tidskriftsartikel (refereegranskat)abstract
- Optical online methods are used to monitor the haemodialysis treatment efficiency of end stage kidney disease (ESKD) patients. The aim of this study was to analyse the effect of the administration of UV-absorbing drugs, such as paracetamol (Par), on the accuracy of optical monitoring the removal of uremic toxins uric acid (UA) and indoxyl sulfate (IS) during standard haemodialysis (HD) and haemodiafiltration (HDF) treatments. Nine patients received Par in daily dosages 1-4 g for 30 sessions. For 137 sessions, in 36 patients the total daily dosage of UV-absorbing drugs was less than 500 mg, and for 6 sessions 3 patients received additional UV-absorbing drugs. Par administration slightly affected the accuracy of optically assessed removal of UA expressed as bias between optically and laboratory-assessed reduction ratios (RR) during HD but not HDF employing UV absorbance of spent dialysate (p < 0.05) at 295 nm wavelength with the strongest correlation between the concentration of UA and absorbance. Corresponding removal of IS based on fluorescence at Ex280/Em400 nm during HD and HDF was not affected. Administration of UV-absorbing drugs may in some settings influence the accuracy of optical assessments in spent dialysate of the removal of uremic solutes during haemodialysis treatment of ESKD patients.
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| 2. |
- Andersson, Roger, et al.
(författare)
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Analysis of the relationship between UV-absorbance of solute contents during a dialysis session
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, the influence from patient anamnesis and haemodialysis session specifications onto the relationship between obtained ultra violet (UV) absorbance and urea concentration in the spent dialysate were discussed. A characterisation of the relationship was done by an intercept value and a slope. Recently, a new a dialysate monitoring device, using UV- absorbance, been developed by our group which has found a relationship between the UV- absorbance and waste products in the dialysate but this relationship vary between patients. In the present investigation, 13 patients performing totally 84 sessions were characterised using 31 possible affecting parameters. Using a multi-regression analysis 11 parameters were found significant as affecting parameters. In a novel mathematical model approach the obtained UV- absorbance and incorporating possible affecting parameters we could predict urea concentration from the UV-absorption in the spent dialysate in the total material of patients and dialysis sessions. For all the 84 sessions R2 between 0.938 and 0.996 were obtained. A performed analysis of variance rejects the assumption of equal conditions for the relationship between diabetics and non-diabetics patients in the material (F=5.2 for intercept and F=14.4 for slope). The urea concentration could be estimated with an accuracy of 11% (one standard deviation) which is normally clinically sufficient. The non-invasive UV -absorption method therefore seems to have great potential for monitoring and control haemodialysis sessions.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Arund, Jürgen, et al.
(författare)
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Do Only Small Uremic Toxins, Chromophores, Contribute to the Online Dialysis Dose Monitoring by UV Absorbance?
- 2012
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Ingår i: Toxins. - : MDPI AG. - 2072-6651. ; 4:10, s. 849-861
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this work was to evaluate the contributions of the main chromophores to the total UV absorbance of the spent dialysate and to assess removal dynamics of these solutes during optical on-line dialysis dose monitoring. High performance chromatography was used to separate and quantify UV-absorbing solutes in the spent dialysate sampled at the start and at the end of dialysis sessions. Chromatograms were monitored at 210, 254 and 280 nm routinely and full absorption spectra were registered between 200 and 400 nm. Nearly 95% of UV absorbance originates from solutes with high removal ratio, such as uric acid. The contributions of different solute groups vary at different wavelengths and there are dynamical changes in contributions during the single dialysis session. However, large standard deviation of the average contribution values within a series of sessions indicates remarkable differences between individual treatments. A noteworthy contribution of Paracetamol and its metabolites to the total UV absorbance was determined at all three wavelengths. Contribution of slowly dialyzed uremic solutes, such as indoxyl sulfate, was negligible.
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| 7. |
- Arund, Jurgen, et al.
(författare)
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Is Fluorescence Valid to Monitor Removal of Protein Bound Uremic Solutes in Dialysis?
- 2016
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 11:5
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the contribution and removal dynamics of the main fluorophores during dialysis by analyzing the spent dialysate samples to prove the hypothesis whether the fluorescence of spent dialysate can be utilized for monitoring removal of any of the protein bound uremic solute. A high performance liquid chromatography system was used to separate and quantify fluorophoric solutes in the spent dialysate sampled at the start and the end of 99 dialysis sessions, including 57 hemodialysis and 42 hemodiafiltration treatments. Fluorescence was acquired at excitation 280 nm and emission 360 nm. The main fluorophores found in samples were identified as indole derivatives: tryptophan, indoxyl glucuronide, indoxyl sulfate, 5-hydroxy-indoleacetic acid, indoleacetyl glutamine, and indoleacetic acid. The highest contribution (35 +/- 11%) was found to arise from indoxyl sulfate. Strong correlation between contribution values at the start and end of dialysis (R-2 = 0.90) indicated to the stable contribution during the course of the dialysis. The reduction ratio of indoxyl sulfate was very close to the decrease of the total fluorescence signal of the spent dialysate (49 +/- 14% vs 51 +/- 13% respectively, P = 0.30, N = 99) and there was strong correlation between these reduction ratio values (R-2 = 0.86). On-line fluorescence measurements were carried out to illustrate the technological possibility for real-time dialysis fluorescence monitoring reflecting the removal of the main fluorophores from blood into spent dialysate. In summary, since a predominant part of the fluorescence signal at excitation 280 nm and emission 360 nm in the spent dialysate originates from protein bound derivatives of indoles, metabolites of tryptophan and indole, the fluorescence signal at this wavelength region has high potential to be utilized for monitoring the removal of slowly dialyzed uremic toxin indoxyl sulfate.
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| 8. |
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| 9. |
- Enberg, Per, et al.
(författare)
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Utilization of UV absorbance for estimation of phosphate elimination during hemodiafiltration
- 2012
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Ingår i: Nephron. Clinical practice. - : S. Karger. - 1660-8151 .- 2235-3186 .- 1660-2110. ; 121:1-2, s. c1-c9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Phosphate is an important factor in explaining the high progress of vascular calcification among dialysis patients. Today, phosphate concentration is measured in plasma on a regular basis. The aim of this study was to find out if it is possible to estimate total removed phosphate (TRp) in spent dialysate utilizing UV absorbance during hemodiafiltration. Methods: Eleven patients were monitored online with UV absorbance at 297 nm, three times during one week each (n = 33). Dialysate samples were taken at different times during treatment and from a collection tank to chemically determine phosphate concentrations. Two mathematical models (UVIND and UVGROUP) were tested to estimate TRp with supervision by UV absorbance and compared with TRp measured in the tank (reference). Results: High correlation between UV absorbance and phosphate concentration for each single patient and lower for the whole group together was found. TRp was (mean +/- SD) 30.7 +/- 7.3 mmol for the reference and 30.8 +/- 8.2 and 29.1 +/- 5.2 mmol for UVIND and UVGROUP, respectively (p > 0.05). Conclusion: This study demonstrates a novel possibility to estimate TRp based on linear relationship between online monitoring of UV absorbance and concentration of phosphate in spent dialysate.
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| 10. |
- Fridolin, Ivo, et al.
(författare)
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A New Optical Method for Measuring Creatinine Concentration Removed During Dialysis
- 2010
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Ingår i: XII Mediterranean Conference on Medical and Biological Engineering and Computing 2010 IFMBE Proceedings, 2010. - Berlin, Heidelberg : Springer. - 9783642130380 - 9783642130397 ; , s. 379-382
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Konferensbidrag (refereegranskat)abstract
- The aim of this study was to compare creatinine (Cr) concentration measurements removed during dialysis by two optical algorithms based on single wavelength and multiwavelength UV-absorbance. Ten uremic patients, three females and seven males, mean age 62.6 ± 18.6 years, on chronic thrice-weekly hemodialysis were included in the study. Double-beam spectrophotometer (Shimatsu UV-2401 PC, Japan) was used for the determination of UV-absorbance in the collected spent dialysate samples. Two optical algorithms were developed to calculate Cr concentration removed during dialysis from measured UVabsorbance: (i) an algorithm utilizing only a single wavelength, revealing Cr concentration Cr_sw; (ii) an algorithm utilizing several wavelengths (multiwavelength algorithm), revealing Cr concentration Cr_mw. The mean value of Cr estimated at the laboratory was 107 ± 46,7 micromol/l, while UV-absorbance as Cr_sw (242 nm) was 107 ± 42.7 micromol/l, and 107 ± 44.7 micromol/l as Cr_mw. The mean concentrations were not significantly different (P = 0.99). The systematic errors, using Cr_lab as a reference, were -2.7% for Cr_sw and -1.7% for Cr_mw, and random errors were 17.3% and 13.6% for Cr_sw and Cr_mw, respectively. The systematic error was not significantly different for two optical algorithms (P = 0.25). The random error decreased significantly (P < 0.05) using Cr_mw algorithm compared to the Cr_sw model. In summary, the creatinine concentration removed during dialysis can be estimated with UV-absorbance technique.
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