Wendroth Scott M, Heady Tiffany N, Haverstick Doris M, Bachmann Lorin M, Scott Mitchell G, Boyd James C, Bruns David E
Department of Pathology, University of Virginia School of Medicine and Health System, Charlottesville, VA, United States.
Department of Pathology, University of Virginia School of Medicine and Health System, Charlottesville, VA, United States.
Clin Chim Acta. 2014 Apr 20;431:77-9. doi: 10.1016/j.cca.2014.01.020. Epub 2014 Feb 7.
Sodium thiosulfate (STS) is used to treat calciphylaxis and cyanide poisoning, but can lead to a serious anion-gap acidosis. We suspected that the calculated anion gap in a patient treated with STS for calciphylaxis was decreased to normal by a falsely increased chloride, and we hypothesized that STS directly interfered with chloride measurements.
Plasma pools were prepared with 12 concentrations of STS from 0 to 20 mmol/l. Chloride was measured in each sample on 9 analyzers: Architect 16200, StatProfile pHOx Plus, RapidLab 1265®, Vitros 350®, Advia 1800, Roche Modular, iSTAT1, RAPIDpoint 500, and Radiometer ABL735.
Statistically significant, dose-dependent increases in reported chloride concentrations were seen with all analyzers except the RAPIDpoint 500 and Vitros. The increases ranged from 5 to 75 mmol/l at the peak thiosulfate concentrations (33 mmol/l) expected in treated patients. The CLIA-allowable error of 5% was exceeded by 4 analyzers (Architect 16200, iSTAT1, StatProfile pHOx Plus, and Radiometer ABL735). The RAPIDpoint 500 showed a 3-mmol/l decrease in measured chloride over the tested range. The Vitros analyzer showed no interference.
Interference of STS in chloride measurement in several common analyzers may lead to erroneous anion-gap calculations and confound the diagnosis of STS-induced anion-gap acidosis.
硫代硫酸钠（STS）用于治疗钙化防御和氰化物中毒，但可导致严重的阴离子间隙酸中毒。我们怀疑，接受STS治疗钙化防御的患者中，计算出的阴离子间隙因氯化物假性升高而降至正常，并且我们推测STS直接干扰了氯化物测量。
制备含有0至20 mmol/l 12种浓度STS的血浆池。在9种分析仪上对每个样本进行氯化物测量：Architect 16200、StatProfile pHOx Plus、RapidLab 1265®、Vitros 350®、Advia 1800、罗氏模块化分析仪、iSTAT1、RAPIDpoint 500和Radiometer ABL735。
除RAPIDpoint 500和Vitros外，所有分析仪均观察到报告的氯化物浓度有统计学意义的剂量依赖性增加。在接受治疗患者预期的硫代硫酸盐峰值浓度（33 mmol/l）下，增加范围为5至75 mmol/l。4种分析仪（Architect 16200、iSTAT1、StatProfile pHOx Plus和Radiometer ABL735）超过了CLIA允许的5%误差。RAPIDpoint 5在此测试范围内测得的氯化物降低了3 mmol/l。Vitros分析仪未显示干扰。
STS对几种常见分析仪中氯化物测量的干扰可能导致错误的阴离子间隙计算，并混淆对STS诱导的阴离子间隙酸中毒的诊断。
