离子透析率与Kt/V评估：V的不同估计值对方法一致性的影响。

Ionic dialysance and the assessment of Kt/V: the influence of different estimates of V on method agreement.

作者信息

Moret Karin, Beerenhout Charles H, van den Wall Bake A Warmold L, Gerlag Paul G, van der Sande Frank M, Leunissen Karel M, Kooman Jeroen P

机构信息

Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands.

出版信息

Nephrol Dial Transplant. 2007 Aug;22(8):2276-82. doi: 10.1093/ndt/gfm108. Epub 2007 Jun 5.

DOI:10.1093/ndt/gfm108

PMID:17550929

Abstract

BACKGROUND

Ionic dialysance was recently introduced as a means to assess Kt/V (K(ID)t/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 K(ID)t/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 K(ID)t/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 (V(Watson); V(Chertow)), double-pool urea kinetic modelling (V(UKM)) and by ionic dialysance (V(IOD)) [Diascan; Hospal(R)].

RESULTS

The use of V(UKM) or V(IOD) instead of V(Watson) or V(Chertow) improved the relation between eKt/V and K(ID)t/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), K(ID)t/V(UKM) (1.19 +/- 0.30) and K(ID)t/V(IOD) (1.21 +/- 0.25) were comparable. Intra-class correlation coefficient of V(IOD) was 0.87 with a 1-month interval and <0.75 after 2 and 3 months. Intra-class correlation coefficient of V(DP) was 0.79 with a 1-month interval and <0.75 after 2 and 3 months. Inter-treatment variation in K(ID)t/V during six consecutive dialysis sessions was 6.1% +/- 0.6%. Changes in blood flow were the main determinant of variations in K(ID)t/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 V(IOD) and V(UKM) results in better agreement between eKt/V and K(ID)t/V compared with anthropometric formulae. K(ID)t/V was comparable with eKt/V and thus lower than expected for a single-pool method. V(IOD) and V(UKM), should be assessed at least monthly. K(ID)t/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.

摘要

背景

离子透析法最近被引入作为评估Kt/V（K(ID)t/V）的一种手段。采用这种方法时，必须估计尿素分布容积（V）。本研究的主要目的是评估在考虑不同V估计值的情况下，通过尿素动力学模型评估的平衡Kt/V（eKt/V）与K(ID)t/V之间的一致性，并评估V的月度变化。其次，评估了离子透析治疗期间变化及K(ID)t/V治疗间变异性背后的机制。

方法

纳入66例患者。使用第二代Daugirdas方程中治疗后30分钟的采样来估计eKt/V。通过Watson和Chertow公式（V(Watson)；V(Chertow)）、双池尿素动力学模型（V(UKM)）以及离子透析法（V(IOD)）[Diascan；Hospal(R)]来评估V。

结果

使用V(UKM)或V(IOD)而非V(Watson)或V(Chertow)可改善eKt/V与K(ID)t/V之间的关系（两者r = 0.93；P < 0.001，相比之下r = 0.84和r = 0.81；P < 0.001）。eKt/V（1.19 ± 0.21）、K(ID)t/V(UKM)（1.19 ± 0.30）和K(ID)t/V(IOD)（1.21 ± 0.25）的平均值具有可比性。V(IOD)的组内相关系数在间隔1个月时为0.87，在2个月和3个月后<0.75。V(DP)的组内相关系数在间隔1个月时为0.79，在2个月和3个月后<0.75。连续6次透析治疗期间K(ID)t/V的治疗间变异为6.1% ± 0.6%。血流量变化是K(ID)t/V变异的主要决定因素（P < 0.05）。治疗期间，离子透析率下降了12 ± 13 ml/分钟（P < 0.001）。血容量下降是离子透析率透析内变化的主要决定因素（P < 0.05）。

结论

与人体测量公式相比，使用V(IOD)和V(UKM)可使eKt/V与K(ID)t/V之间具有更好的一致性。K(ID)t/V与eKt/V具有可比性，因此低于单池法预期值。应至少每月评估一次V(IOD)和V(UKM)。连续透析治疗期间K(ID)t/V差异很大，主要是由于血流量不同。治疗期间，离子透析率降低，这与血容量的相对下降有关。