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.
References
[1]
Beto, J.; Bansal, V. Variation in blood sample collection for determination of hemodialysis adequacy. Am. J. Kidney Dis. 1998, 31, 135–141, doi:10.1053/ajkd.1998.v31.pm9428465.
[2]
Johnson, W.; Hagge, W. Effects of urea loading in patients with far-advanced renal failure. Mayo Clinic Proc. 1972, 47, 21–29.
[3]
Krieter, D.; Hackl, A. Protein-bound uraemic toxin removal in haemodialysis and post-dilution haemodiafiltration. Nephrol. Dial. Transplant. 2010, 25, 212–218, doi:10.1093/ndt/gfp437.
[4]
Gal, G.; Grof, J. Continuous UV photometric monitoring of the efficiency of hemodialysis. Int. J. Artif. Organs 1980, 3, 338–341.
[5]
Polaschegg, H. Automatic, non-invasive intradialytic clearance measurement. Int. J. Artif. Organs 1993, 16, 185–191.
[6]
Petitclerc, T.; Goux, N. A model for non-invasive estimation of in vivo dialyzer perfomances and patient’s conductivity during hemodialysis. Int. J. Artif. Organs 1993, 16, 585–591.
[7]
Lindley, E.; de Vos, J. On line UV-adsorbance measurements. Summary of the EDTNA/ERCA journal club discussion. Summer 2006. J. Renal Care 2006, 33, 41–48, doi:10.1111/j.1755-6686.2007.tb00037.x.
[8]
Keshaviah, P.; Ebben, J. Clinical evaluation of a new on-line monitor of dialysis adequacy. J. Am. Soc. Nephrol. 1992, 3, 374.
[9]
Keshaviah, P.; Ebben, J. On-line monitoring of the delivery of the hemodialysis prescription. Pediatri. Nephrol. 1995, 9, S2–S8, doi:10.1007/BF00867675.
[10]
Lim, P.S.; Lee, H. Evaluation of pre- and postdilutional on-line hemodiafiltration adequacy by partial dialysate quantification and on-line urea monitor. Blood Purif. 1999, 17, 199–205, doi:10.1159/000014396.
[11]
Uhlin, F.; Fridolin, I. Estimation of delivered dialysis dose by on-line monitoring of the UV-absorbance in the spent dialysate. Am. J. Kidney Dis. 2003, 41, 1026–1036, doi:10.1016/S0272-6386(03)00200-2.
[12]
Scherbakov, A.; Fridolin, I. Dialysis Adequacy On-line Monitoring Using DiaSens Optical Sensor: Technique and Clinical Application. In Proceedings of 14th Nordic-Baltic Conference on Biomedical Engineering and Medical Physics, NBC-2008, Riga, Latvia, 16–20 June 2008.
[13]
Fridolin, I.; Magnusson, M. On-line monitoring of solutes in dialysate using absorption of ultraviolet radiation: Technique description. Int. J. Artif. Organs 2002, 25, 748–761.
[14]
Uhlin, F.; Fridolin, I. Dialysis dose (Kt/V) and clearance variation sensitivity using measurement of ultraviolet-absorbance (on-line), blood urea, dialysate urea and ionic dialysanc. Nephrol. Dial. Transplant. 2006, 21, 2225–2231, doi:10.1093/ndt/gfl147.
[15]
Castellarnau, A.; Werner, M. Real-time Kt/V determination by ultraviolet absorbance in spent dialysate: technique validation. Kidney Int. 2010, 78, 920–925.
[16]
Daugirdas, J.T.; Tattersall, J. Automated monitoring of hemodialysis adequacy by dialysis machines: Potential benefits to patients and cost savings. Kidney Int. 2010, 78, 833–835, doi:10.1038/ki.2010.218.
[17]
Vanholder, R.; de Smet, R. Review on uremic toxins: Classification, concentration, and interindividual variability. Kidney Int. 2003, 63, 1934–1943, doi:10.1046/j.1523-1755.2003.00924.x.
[18]
Uhlin, F.; Fridolin, I. Optical Monitoring of Dialysis Dose. In Modeling and Control of Dialysis Systems; Azar, A.T., Ed.;. Studies in Computation Intelligence Springer-Verlag: Berlin/Heidelberg, Germany, 2013; Volume 405, pp. 867–928.
[19]
Schoots, A.; Peeters, J. Effect of Hemodialysis on Serum Concentrations of HPLC—Analyzed Accumulating Solutes in Uremia. Nephron 1989, 53, 208–217, doi:10.1159/000185746.
[20]
Vanholder, R.; de Smet, R. Assessment of urea and other uremic markers for quantification of dialysis efficacy. Clin. Chem. 1992, 38, 1429–1436.
[21]
Lauri, K.; Tanner, R. HPLC study of uremic fluids related to optical dialysis adequacy monitoring. Int. J. Artif. Organs 2010, 33, 96–104.
[22]
Jerotskaja, J.; Uhlin, F. Concentration of uric acid removed during dialysis. Estimated by multi wavelength and processed ultra violet absorbance spectra. In Proceedings of 32nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society 2010, Buenos Aires, Argentina, 31 August–4 September 2010; pp. 5791–5794.
[23]
Luman, M.; Jerotskaja, J. Dialysis dose and nutrition assessment by optical on-line dialysis adequacy monitor. Clini. Nephrol. 2009, 72, 303–311.
[24]
Holmar, J.; Fridolin, I.; Uhlin, F.; Lauri, K.; Luman, M. Optical Method for Cardiovascular Risk Marker Uric Acid Removal Assessment During Dialysis. Sci. World J. 2012, 2012, 506486:1–506486:8.
[25]
Tanner, R.; Arund, J. Impact of Paracetamol on Optical On-Line Dialysis Monitoring and on Uricemia. In Proceedings of 49th ERA/EDTA Congress 2012, Paris, France, 24–27 May 2012.
[26]
Sirich, T.; Luo, F. Selectively increasing the clearance of protein-bound uremic solutes. Nephrol. Dial. Transplant. 2012, 27, 1574–1579, doi:10.1093/ndt/gfr691.
[27]
Holmar, J.; Arund, J. Quantification of Indoxyl Sulphate in the Spent Dialysate Using Fluorescence Spectra. In Proceedings of 15th Nordic-Baltic Conference on Biomedical Engineering and Medical Physics (NBC15), Aalborg, Denmark, 14–17 June 2011.
