Abstract

GEM Premier ChemSTAT is a whole-blood analyzer designed for providing a rapid basic metabolic panel, inclusive of creatinine and blood urea nitrogen, with the unique characteristic of providing measured bicarbonate (HCO₃^–) levels. The aim of this work was to evaluate the clinical performance of HCO₃^– assessment with this analyser in a real-life hemodialysis setting. Imprecision was calculated at different HCO₃^– levels, along with assay comparison with Gem Premier 4000 analysers. GEM Premier ChemSTAT displayed an imprecision and a bias (in comparison to GEM Premier 4000) for HCO₃^– of 0.4% and 37.3% at 20.8 mmol/L, 1.2% and 25.6% at 16.4 mmol/L, and 2.1% and 11.6% at 11.5 mmol/L, respectively, using three levels of HCO₃^– quality control sample ChemSTAT System Evaluator. At direct comparison with the GEM Premier 4000 in the hemodialysis setting, Bland–Altman analysis of HCO₃^– levels evidenced a bias (µ) of −4.9 (95% CI, −5.2 to −4.7) mmol/L. Such difference was attenuated by recalculating the GEM ChemSTAT expected HCO₃^– values from pH and pCO₂ using the Henderson Hasselbach equation, µ=–0.07 (95%CI, −0.19 to 0.05) mmol/L (p = .24). In conclusion, our results show a remarkable difference between the HCO₃^– values reported by GEM ChemSTAT or GEM 4000. New reference values for GEM ChemSTAT HCO₃^– shall hence be defined according to our findings. We suggest that further investigation and a re-evaluation of the reference range should be made before extending the clinical use of this device.

摘要

GEM Premier ChemSTAT 是一款全血分析仪，旨在提供快速的基本代谢面板，包括肌酐和血尿素氮，具有提供测量碳酸氢盐 (HCO ₃ ^– ) 水平的独特特性。这项工作的目的是评估 HCO _{3的临床性能}^-在现实血液透析环境中使用该分析仪进行评估。计算了不同 HCO _3水平^的不精密度，并与 Gem Premier 4000 分析仪进行了分析比较。GEM Premier ChemSTAT 显示 HCO _{3的不精确性和偏差（与 GEM Premier 4000 相比）} ^–在 20.8 mmol/L 时为 0.4% 和 37.3%，在 16.4 mmol/L 时为 1.2% 和 25.6%，在 11.5 mmol/L 时分别为 2.1% 和 11.6%，使用三个水平的 HCO ₃ ^–质量控制样品 ChemSTAT System Evaluator . 在与血液透析环境中的 GEM Premier 4000 直接比较时，HCO ₃ ^–水平的 Bland-Altman 分析表明偏差 ( µ ) 为 -4.9（95% CI，-5.2 至 -4.7）mmol/L。通过使用 Henderson Hasselbach 方程重新计算 GEM ChemSTAT 预期的 HCO ₃ ^–来自 pH 和 pCO _{2的值，可以减弱这种差异，} µ =–0.07 (95%CI, -0.19 至 0.05) mmol/L ( p = .24)。总之，我们的结果显示 HCO ₃ ^{（由 GEM ChemSTAT 或 GEM 4000 报告的值）之间存在显着差异。因此，}应根据我们的研究结果定义GEM ChemSTAT HCO ₃的新参考值。我们建议在扩大该设备的临床使用范围之前，应进一步调查和重新评估参考范围。