Marsenic Olivera, Booker Kristi, Studnicka Kathleen, Wilson Donna, Beck Ann, Swanson Tiffany, Henry Dwayne, Turman Martin
Pediatric Nephrology, Oklahoma University Health Sciences Center, Oklahoma City, Oklahoma, USA.
Hemodial Int. 2011 Oct;15 Suppl 1:S2-8. doi: 10.1111/j.1542-4758.2011.00595.x.
Online clearance (OLC) monitor measures conductivity difference between dialysate entering and leaving the dialyser. Derived ionic dialysance (ID) represents effective urea clearance from which Kt/V is calculated, allowing Kt/V monitoring at every treatment without blood sampling. We tested ID accuracy in children and provide recommendations for its use. Using Fresenius machines 2008 K with built-in OLC monitors, we studied 45 hemodialysis (HD) sessions and 168 calculated Kt/V results in 11 patients. Urea distribution volume (V), needed to calculate Kt/V from ID, was estimated using three methods: Mellits and Cheek (MC), KDOQI recommended total body water nomograms (TBWN) and OLC-derived independent from tested HD sessions. Reference spKt/V from pre- and post-HD BUN (Daugirdas) was compared with Kt/V calculated from ID using three different estimated V's. ID was accurate in calculating Kt/V in children when V derived from OLC was used (P = 0.42), with absolute error 0.14 ± 0.12. If TBWN-derived V was used, Kt/V was consistently underestimated by 0.32 ± 0.22. TBWN-derived V can still be recommended for use with OLC for monitoring trend in Kt/V, if underestimation of spKt/V of average 0.3 is accounted for. MC-derived V results in even greater underestimation of spKt/V and therefore cannot be recommended for use with OLC.
在线清除率（OLC）监测仪可测量进入和离开透析器的透析液之间的电导率差异。导出的离子透析率（ID）代表有效的尿素清除率，据此计算Kt/V，从而无需采血即可在每次治疗时监测Kt/V。我们测试了ID在儿童中的准确性，并给出了使用建议。使用配备内置OLC监测仪的费森尤斯2008 K型机器，我们研究了11例患者的45次血液透析（HD）治疗过程以及168个计算得出的Kt/V结果。使用三种方法估算从ID计算Kt/V所需的尿素分布容积（V）：梅利茨和奇克（MC）法、KDOQI推荐的总体水列线图（TBWN）法以及独立于所测试HD治疗过程的OLC导出法。将HD前后血尿素氮（Daugirdas法）得出的参考标准化Kt/V与使用三种不同估算V值从ID计算得出的Kt/V进行比较。当使用源自OLC的V时，ID在计算儿童Kt/V方面是准确的（P = 0.42），绝对误差为0.14 ± 0.12。如果使用源自TBWN的V，Kt/V始终被低估0.32 ± 0.22。如果考虑到平均spKt/V被低估0.3，源自TBWN的V仍可推荐与OLC一起用于监测Kt/V的变化趋势。源自MC的V会导致spKt/V被更大程度地低估，因此不建议与OLC一起使用。
