Kanagasundaram N S, Larive A B, Paganini E P
Section of Dialysis and Extracorporeal Therapy and Department of Biostatistics and Epidemiology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Kidney Int. 2000 Dec;58(6):2579-84. doi: 10.1046/j.1523-1755.2000.00444.x.
Fractional direct dialysis quantification (fDDQ), whereby a known proportion of dialysate effluent is sampled, can reliably estimate total solute removal in intermittent hemodialysis (IHD). Our study aimed to develop and test the technique in continuous venovenous hemodialysis (CVVHD).
Twenty dialysate collections (mean duration 23.5 hours, range 17.25 to 26.6) were performed in 12 patients on CVVHD. An infusion pump diverted 10% of the total effluent volume to the fractional collection (fc), the remainder being channeled into the bulk collection (bc). Both fc and bc were collected on ice and assayed for urea nitrogen (UN) and creatinine (Cr). Actual solute removal (ASR) was calculated from the measured effluent volume and solute concentrations of the fc and bc. Estimated solute removal (ESR) was calculated from the product of the fc solute concentration and effluent volume. All fc/bc samples in 15 out of 20 collections underwent gram stain and aerobic/anaerobic culture.
Bland-Altman analyses suggested good agreement between ASR and ESR [absolute values of percentage differences: 95% CI = 1.73, 5.17% (UN); 1.88, 4.31% (Cr)]. Favorable concordance correlation coefficients confirmed this [rc = 0.995 (UN), 0.997 (Cr)] and were apparently unaffected by heavy pseudomonal growths in 4 out of 7 culture positive collections [rc = 0.997 (UN), 0.997 (Cr); culture negative (N = 8), rc = 0.996 (UN), 0.997 Cr)].
fDDQ, using 24-hour, pump-assisted, cooled fractional dialysate sampling reliably estimates total solute removal and provides a practical alternative to total dialysate collection in assessing delivered dialysis dose.
分数直接透析定量法（fDDQ），即对已知比例的透析液流出物进行采样，能够可靠地估计间歇性血液透析（IHD）中溶质的总清除量。我们的研究旨在开发并在持续性静脉-静脉血液透析（CVVHD）中测试该技术。
对12例接受CVVHD治疗的患者进行了20次透析液收集（平均时长23.5小时，范围17.25至26.6小时）。一台输液泵将总流出液体积的10%转移至分数收集器（fc），其余部分则导入总体收集器（bc）。fc和bc均在冰上收集，并检测尿素氮（UN）和肌酐（Cr）。根据测得的流出液体积以及fc和bc的溶质浓度计算实际溶质清除量（ASR）。根据fc溶质浓度与流出液体积的乘积计算估计溶质清除量（ESR）。20次收集中有15次的所有fc/bc样本均进行了革兰氏染色及需氧/厌氧培养。
Bland-Altman分析表明ASR与ESR之间具有良好的一致性[百分比差异的绝对值：95%置信区间 = 1.73, 5.17%（UN）；1.88, 4.31%（Cr）]。良好的一致性相关系数证实了这一点[rc = 0.995（UN），0.997（Cr）]，并且显然不受7次培养阳性收集样本中4次出现的大量假单胞菌生长的影响[rc = 0.997（UN），0.997（Cr）；培养阴性（N = 8），rc = 0.996（UN），0.997 Cr]。
使用24小时泵辅助冷却分数透析液采样的fDDQ能够可靠地估计溶质的总清除量，并为评估透析剂量时的总体透析液收集提供了一种实用的替代方法。
