Scientific Online Resource System

Actual Nephrology

Evaluation of Dialysis Adequacy in Real Time by Ionic Dialysis—Reliability and Comparability of the Method

Diana Nenova


Despite the progress made, the unsatisfactory results in the growing population of dialysis patients show that improved patient care is still not enough to increase survival and quality of life. The question of the need to improve hemodialysis therapies, which has been the subject of research and discussion for many years, remains relevant. Dialysis adequacy and the need for its quantitative measurement have been the subject of discussions since the dawn of hemodialysis treatment. It should be borne in mind that it is most often monitored once a month and by standards in some countries—every three months, and, based on the value obtained for the dialysis session, it is assumed that the result is representative of urea clearance of the entire dialysis. Measurement of dialysis adequacy is now achievable for each dialysis session without the need for additional blood tests and the results are available in real time using the ionic dialysis method, which registers the difference in sodium ionic conductivity at the inlet and outlet of the dialyzer of the dialysis dose delivered. A total of 128 measurements of the delivered dialysis dose by ionic dialysis and classical urea-kinetic modeling were performed at 32 chroniodialysis patients at the Clinic of Nephrology and Dialysis at the St. Marina University Hospital in Varna for a period of one year to assess the reliability and comparability of both methodologies, as well as the development of new therapeutic strategies with a view to improving the outcome.


adequacy, dose, ionic dialysis, urea-kinetic modeling, sodium concentration

Full Text


Ahrenholz P, Taborsky P, Bohling M, Rawer P, Ibrahim N, Gajdos M, Machek P, Sagova M, Gruber H, Moucka P, Rychlik I, Leimenstoll G, Vyskocil P, Toenne G, Possnickerova J, Woggan J, Riegel W, Schneider H, Wojke R. Determination of dialysis dose: a clinical comparison of methods. Blood Purif. 2011;32(4):271-7.

Alayoud A, Montassir D, Hamzi A, et al. The Kt/V by ionic dialysance: Interpretation limits. Indian J Nephrol. 2012;22(5):333-339.

Aslam S, Saggi SJ, Salifu M, Kossmann RJ. Online measurement of hemodialysis adequacy using effective ionic dialysance of sodium-a review of its principles, applications, benefits, and risks. Hemodial Int. 2018 Oct;22(4):425-434.

Churchill BM, Patri P. The Nitty-Gritties of Kt/Vurea Calculations in Hemodialysis and Peritoneal Dialysis. Indian J Nephrol. 2021 Mar-Apr;31(2):97-110.

Créput C, Toledano D, Petitclerc T. Ionic dialysance and determination of Kt/V in on-line hemodiafiltration with simultaneous pre- and post-dilution. Int J Artif Organs. 2013 May 17;36(5):327-34.

Daugirdas JT, Tattersall JE. Automated monitoring of hemodialysis adequacy by dialysis machines: potential benefits to patients and cost savings. Kidney Int 2010; 78: 833–835

Di Filippo S, Manzoni C, Andrulli S, Pontoriero G, Dell’Oro C, La Milia V, et al. How to determine ionic dialysance for the online assessment of delivered dialysis dose? Kidney Int. 2001;59: 774–82

Ding L, Johnston J, Pinsk MN. Monitoring dialysis adequacy: history and current practice. Pediatr Nephrol. 2021 Aug;36(8):2265-2277

Eknoyan G, Beck GJ, Cheung AK, et al. Effect of dialysis dose and membrane flux in maintenance hemodialysis. N Engl J Med. 2002; 347: 2010– 2019.

García Testal A, García Maset R, Fornés Ferrer V, Cañada Martínez AJ, Rico Salvador IS, Royo Maicas P, Fernández Najera JE, Olagüe Díaz P, Benedito Carrera C, Torregrosa De Juan E. Influential factors on dose by ionic dialysance in daily practice in chronic hemodialysis. Nephrol Ther. 2021 Apr;17(2):101-107.

Goldau R, Kuhlmann U, Samadi N, Gross M, Graf T, Orlandini G, et al. Ionic dialysance measurement is urea distribution volume dependent: A new approach to better results. Artif Organs. 2002; 26:321–32.

Gotch FA, Panlilio FM, Buyaki RA, Wang EX, Folden TI, Levin NW. Mechanisms determining the ratio of conductivity clearance to urea clearance. Kidney Int Suppl. 2004; 89: S3–24.

Kim, H.W., Heo, SJ., Kim, J.Y. et al. Dialysis adequacy predictions using a machine learning method. Sci Rep 2021; 11, 15417

Koubaa A, Potier J, de Preneuf H, Queffelou G, Garcia F, Petitclerc T. Estimation of urea distribution volume in hemodialysis patients. Néphrol Thér. 2010; 6:532–6.

Lindley EJ, Chamney PW, Wuepper A, Ingles H, Tattersall JE, Will EJ. A comparison of methods for determining urea distribution volume for routine use in online monitoring of haemodialysis adequacy. Nephrol Dial Transplant. 2009; 24:211–6.

Locatelli F., Manzoni C., Pontoriero G., Cavalli A., Di Filippo S., Azar A.T. (2013) Ionic Dialysance and Conductivity Modeling. In: Azar A. (eds) Modeling and Control of Dialysis Systems. Studies in Computational Intelligence, vol 405. Springer, Berlin, Heidelberg.

McIntyre CW, Lambie SH, Taal MW, Fluck RJ. Assessment of haemodialysis adequacy by ionic dialysance: Intra–patient variability of delivered treatment. Nephrol Dial Transplant. 2003; 18:559–63.

Mohamed A, Davenport A. Comparison of methods to estimate haemodialysis urea clearance. Int J Artif Organs. 2018 Jul;41(7):371-377.

Moret K, Beerenhout CH, Warmold A, van den Wall Bake L, Gerlag PG, van der Sande FM, Leunissen KM, Kooman JP, Ionic dialysance and the assessment of Kt/V: the influence of different estimates of V on method agreement, NephrolDial Transplant, 2007; 22 ( 8):2276–2282.

National Kidney Foundation. KDOQI clinical practice guideline for hemodialysis adequacy: 2015 update. Am J Kidney Dis. 2015;66(5):884-930.

Parker TF, Laird NM, Lowrie EG. Comparison of the study groups in the National Cooperative Dialysis Study and a description of morbidity, mortality, and patient withdrawal. Kidney Int Suppl 1983; S42.

Raimann JG, Ye X, Kotanko P, Daugirdas JT. Routine Kt/V and Normalized Protein Nitrogen Appearance Rate Determined From Conductivity Access Clearance With Infrequent Postdialysis Serum Urea Nitrogen Measurements. Am J Kidney Dis. (2020);76(1):22-31.

Rodriguez A, Morena M, Bargnoux AS, Chenine L, Leray-Moragues H, Cristol JP, Canaud B. Quantitative assessment of sodium mass removal using ionic dialysance and sodium gradient as a proxy tool: Comparison of high-flux hemodialysis versus online hemodiafiltration. Artif Organs. 2021 Aug;45(8): E280-E292.

Ross EA, Paugh-Miller JL, Nappo RW. Interventions to improve hemodialysis adequacy: protocols based on real-time monitoring of dialysate solute clearance. Clin Kidney J. 2018 Jun;11(3):394-399.

Shafi T. (2017) Hemodialysis: Prescription and Assessment of Adequacy. [Internet]. Renal and urology news; [updated 2017; cited 2022 Jan 11]. Available from:

Wuepper A, Tattersall J, Kraemer M, Wilkie M, Edwards L. Determination of urea distribution volume for Kt/V assessed by conductivity monitoring. Kidney Int. 2003;64: 2262–71.



About The Author

Diana Nenova
Clinic of Nephrology and Dialysis, St. Marina University Hospital, Medical University of Varna Second Department of Internal Diseases, Faculty of Medicine, Medical University of Varna

Font Size