NDT Advance Access originally published online on June 5, 2007
Nephrology Dialysis Transplantation 2007 22(8):2276-2282; doi:10.1093/ndt/gfm108
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ionic dialysance and the assessment of Kt/V: the influence of different estimates of V on method agreement
1Department of Internal Medicine, Máxima Medical Centre, Veldhoven and 2Department of Internal Medicine, University Hospital, Maastricht, The Netherlands
Correspondence and offprint requests to: Jeroen P. Kooman, University Hospital Maastricht, PO Box 5800, 6202 AZ Maastricht, The Netherlands. Email: jkoo{at}sint.azm.nl
 |
Abstract |
|---|
Background. Ionic dialysance was recently introduced as a means to assess Kt/V (KIDt/V). With this method, urea distribution volume (V) has to be estimated. The primary aim of the present study was to assess the agreement between equilibrated Kt/V assessed by urea kinetic modelling (eKt/V) with KIDt/V taking into account different estimates of V, and to assess the monthly variation in V. Secondly, the mechanisms behind the intra-treatment changes in ionic dialysance and inter-treatment variability of KIDt/V were assessed.
Methods. Sixty-six patients were included. eKt/V was estimated using 30 min post-treatment sampling in the second generation Daugirdas equation. V was assessed by the formulae of Watson and Chertow (VWatson; VChertow), double-pool urea kinetic modelling (VUKM) and by ionic dialysance (VIOD) [Diascan; Hospal®].
Results. The use of VUKM or VIOD instead of VWatson or VChertow improved the relation between eKt/V and KIDt/V (both r = 0.93; P < 0.001 vs r = 0.84 and r = 0.81; P < 0.001). Mean values of eKt/V (1.19 ± 0.21), KIDt/VUKM (1.19 ± 0.30) and KIDt/VIOD (1.21 ± 0.25) were comparable.
Intra-class correlation coefficient of VIOD was 0.87 with a 1-month interval and <0.75 after 2 and 3 months. Intra-class correlation coefficient of VDP was 0.79 with a 1-month interval and <0.75 after 2 and 3 months.
Inter-treatment variation in KIDt/V during six consecutive dialysis sessions was 6.1% ± 0.6%. Changes in blood flow were the main determinant of variations in KIDt/V (P < 0.05). During treatment, ionic dialysance decreased by 12 ± 13 ml/min (P < 0.001). The decline in blood volume was the major determinant of the intra-dialytic change in ionic dialysance (P < 0.05).
Conclusion. The use of VIOD and VUKM results in better agreement between eKt/V and KIDt/V compared with anthropometric formulae. KIDt/V was comparable with eKt/V and thus lower than expected for a single-pool method. VIOD and VUKM, should be assessed at least monthly. KIDt/V varies widely between consecutive dialysis sessions, mainly due to differences in blood flow. During treatment, ionic dialysance decreases, which is related to the relative decline in blood volume.
Keywords: dialysis dose; ionic dialysance; Kt/V; variability; urea distribution volume
Received for publication: 14. 6.06
Accepted in revised form: 8. 2.07
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  K. Moret, D. C. Grootendorst, C. Beerenhout, and J. P. Kooman Conductivity pulses needed for Diascan(R) measurements: does it cause sodium burden? NDT Plus, May 27, 2009; (2009) sfp059v1. [Full Text] [PDF]
|
|
|
|
 |
|
 E. J. Lindley, P. W. Chamney, A. Wuepper, H. Ingles, J. E. Tattersall, and E. J. Will A comparison of methods for determining urea distribution volume for routine use in on-line monitoring of haemodialysis adequacy Nephrol. Dial. Transplant., January 1, 2009; 24(1): 211 - 216. [Abstract] [Full Text] [PDF]
|
|