Abstract
Background
The dialysis dose (Kt/V) and normalized protein catabolic rate (PCRn) are the most useful indices derived from the urea kinetic model (UKM) in haemodialysis (HD) patients. The kidney urea clearance (Kru) is another important UKM parameter which plays a key role in the prescription of incremental HD. Ideally, the three kinetic parameters should be assessed using the complex software Solute Solver based on the double pool UKM. In the clinical setting, however, the three indices are estimated with simplified formulae. The recently introduced software SPEEDY assembles the aforementioned equations in a plain spreadsheet, to produce quite accurate results of Kru, Kt/V and PCRn. Unfortunately, specific equations to compute Kt/V and PCRn for patients on a once-weekly HD regimen (1HD/wk) were not available at the time SPEEDY was built-up. We devised a new version of SPEEDY (SPEEDY-1) and an even simpler variant (SPEEDY-1S), using two recently published equations for the 1HD/wk schedule . Moreover, we also added a published equation to estimate the equivalent renal clearance (EKR) normalized to urea distribution volume (V) of 35 L (EKR35) from Kru and Kt/V . Aim of the present study was to compare the results obtained using the new methods (SPEEDY-1 and SPEEDY-1S) with those provided by the reference method Solute Solver.
Subjects and methods
One hundred historical patients being treated with the once-weekly HD regimen were enrolled. A total of 500 HD sessions associated to the availability of monthly UKM studies were analysed in order to obtain Kru, single pool Kt/V (spKt/V), equilibrated Kt/V (eKt/V), V, PCRn and EKR35 values by using Solute Solver, SPEEDY-1 and SPEEDY-1S.
Results
When comparing the paired values of the above UKM parameters, as computed by SPEEDY-1 and Solute Solver, respectively, all differences but one were statistically significant at the one-sample t-test; however, the agreement limits at Bland–Altman analysis showed that all differences were negligible. When comparing the paired values of the above UKM parameters, as computed by SPEEDY-1S and Solute Solver, respectively, all differences were statistically significant; however, the agreement limits showed that the differences were negligible as far as Kru, spKt/V and eKt/V are concerned, though much larger regarding V, PCRn and EKR35.
Conclusions
We implemented SPEEDY with a new version specific for the once-weekly HD regimen, SPEEDY-1. It provides accurate results and is presently the best alternative to Solute Solver. Using SPEEDY-1S led to a larger difference in PCRn and EKR35, which could be acceptable for clinical practice if SPEEDY-1 is not available.
Graphic abstract
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Gotch FA, Sargent JA (1985) A mechanistic analysis of the National Cooperative Dialysis Study (NCDS). Kidney Int 28:526–534
Keshaviah PR, Emerson PF, Nolph KD (1999) Timely initiation of dialysis: a urea kinetic approach. Am J Kidney Dis 33:344–348
Daugirdas JT, Depner TA, Greene T et al (2009) Solute-solver: a web-based tool for modeling urea kinetics for a broad range of hemodialysis schedules in multiple patients. Am J Kidney Dis 54:798–809
National Kidney Foundation (2015) KDOQI clinical practice guidelines for hemodialysis adequacy: 2015 update. Am J Kidney Dis 66:884–930
Daugirdas JT (1993) Second generation logarithmic estimates of single-pool variable volume Kt/V: an analysis of error. J Am Soc Nephrol 4:1205–1213
Daugirdas JT, Leypoldt KJ, Akonur A, The FHN Trial Group et al (2013) Improved equation for estimating single-pool Kt/V at higher dialysis frequencies. Nephrol Dial Transpl 28:2156–2160
Depner TA, Daugirdas JT (1996) Equations for normalized protein catabolic rate based on two-point modeling of hemodialysis urea kinetics. J Am Soc Nephrol 7:780–785
Daugirdas JT (2017) Errors in computing the normalized protein catabolic rate due to use of single-pool urea kinetic modeling or to omission of the residual kidney urea clearance. J Ren Nutr 27:256–259
Daugirdas JT (2016) Estimating time-averaged serum urea nitrogen concentration during various urine collection periods: a prediction equation for thrice weekly and biweekly dialysis schedules. Semin Dial 29:507–509
Obi Y, Kalantar-Zadeh K, Streja E et al (2018) Prediction equation for calculating residual kidney urea clearance using urine collections for different hemodialysis treatment frequencies and interdialytic intervals. Nephrol Dial Transpl 33:530–539
Casino FG, Basile C (2018) A user-friendly tool for incremental haemodialysis prescription. Nephrol Dial Transpl 33:1046–1053
Casino FG, Deira J, Suárez MA et al (2021) Improving the “second generation Daugirdas equation” to estimate Kt/V on the once-weekly haemodialysis schedule. J Nephrol. https://doi.org/10.1007/s40620-020-00936-5
Casino FG, Mostacci SD, Sabato A et al (2020) The lacking equation that estimates the protein catabolic rate in patients on once-weekly haemodialysis. J Nephrol. https://doi.org/10.1007/s40620-020-00843-9
Casino FG, Basile C (2017) The variable target model: a paradigm shift in the incremental haemodialysis prescription. Nephrol Dial Transpl 32:182–190
Tattersall JE, DeTakats D, Chamney P et al (1996) The post-hemodialysis rebound: predicting and quantifying its effect on Kt/V. Kidney Int 50:2094–2102
Michaels AS (1966) Operating parameters and performance criteria for hemodialyzers and other membrane-separation devices. Trans Am Soc Artif Intern Organs 12:387–392
Daugirdas JT, Smye SW (1997) Effect of a two-compartment distribution on apparent urea distribution volume. Kidney Int 51:1270–1273
Watson PE, Watson ID, Blatt RD (1980) Total body water volumes for adult males and females estimated from simple anthropometric measurements. Am J Clin Nutr 33:27–29
Bland JM, Altman DG (1986) Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 327:307–310
Kalantar-Zadeh K, Casino FG (2014) Let us give twice-weekly hemodialysis a chance: revisiting the taboo. Nephrol Dial Transpl 29(9):1618–1620
Caria S, Cupisti A, Sau G, Bolasco P (2014) The incremental treatment of ESRD: a low-protein diet combined with weekly hemodialysis may be beneficial for selected patients. BMC Nephrol 15:172
Wong J, Vilar E, Davenport A et al (2015) Incremental haemodialysis. Nephrol Dial Transpl 30:1639–1648
Obi Y, Streja E, Rhee CM, Ravel V, Amin AN, Cupisti A, Chen J, Mathew AT, Kovesdy CP, Mehrotra R (2016) Kalantar-zadeh k incremental hemodialysis, residual kidney function, and mortality risk in incident dialysis patients: a cohort study. Am J Kidney Dis 68(2):256–265
Garofalo C, Borrelli S, De Stefano T et al (2019) Incremental dialysis in ESRD: systematic review and meta-analysis. J Nephrol 32:823–836
Basile C, Casino FG (2019) Incremental haemodialysis and residual kidney function: more and more observations but no trials. Nephrol Dial Transpl 34:1806–1811
Deira J, Suárez MA, López F et al (2019) IHDIP: a controlled randomized trial to assess the security and effectiveness of the incremental hemodialysis in incident patients. BMC Nephrol 20(1):8. https://doi.org/10.1186/s12882-018-1189-6
Casino FG, Basile C, Kirmizis D et al (2020) The reasons for a clinical trial on incremental haemodialysis. Nephrol Dial Transpl 35:2015–2019
Daugirdas JT, Greene T, Depner T, for the Hemodialysis (HEMO) Study Group et al (2003) Anthropometrically estimated total body water volumes are larger than modeled urea volume in chronic hemodialysis patients: effects of age, race and gender. Kidney Int 64:1108–1119
Funding
No funding agency granted the present study.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Ethical approval
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Research involving human participants and/or animals
This article does not contain any studies with animals performed by any of the authors.
Informed consent
Informed consent was obtained from all individual participants included in the study.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Appendix
Numerical example of the use of SPEEDY-1S with input data from a patient.
Supplementary Information
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Casino, F.G., Deira, J., Suárez, M.A. et al. Routine assessment of kidney urea clearance, dialysis dose and protein catabolic rate in the once-weekly haemodialysis regimen. J Nephrol 34, 2009–2015 (2021). https://doi.org/10.1007/s40620-021-01033-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s40620-021-01033-x