Background While i-STAT® cartridges offer the Physician a spectrum of analytical methods at the point of care for prompt diagnosis and interventions, these methods have to be harmonized with the laboratory methods in order to reliably detect shifts and trends. With this practical example we illustrate the importance of a program of routine comparisons between the i-STAT® and laboratory methods to detect analytical differences exceeding the CLIA’s criterion and potentially having adverse clinical implications. Methods Patient blood chloride (Cl), potassium (K) and sodium (Na) values as obtained by nurses with i-STAT Chem 8 ™ cartridges (Abbott Laboratories) at the point of care, where daily compared with the values as obtained with the Laboratory method (two cobas 6000®, Roche Diagnostics) using green top BD® lithium heparin tubes (Becton Dickinson) collected within thirty minutes of the i-STAT assay. The data were electronically stored in RALS™ (RALS Informatics) and transferred to Minitab® (Version 21, Minitab Inc.) statistical software. The two analytical methods were compared using the orthogonal and the polynomial ordinary least squares (POLS) regression models and their graphic representations. The aptness of the methods was evaluated with the standardized residuals diagnostics for normality, independence, outliers (Standardized residual >|3|) and influential observations (Hi>0.5). For acceptance of the differences the CLIA’s total error criterion was employed. (CI: target value ± 5%; K: target value ± 0.5 mmol/L; Na: target value ± 4 mmol/L). Results In the first four months of the study the number of differences exceeding the CLIA’s criterion was not acceptable. [Cl: 10% (165/1564); K: 7% (109/1593); Na: 4% (66/1586)]. These differences were occurring throughout the analytical range (AMR). Consequently, the operator’s technique was suspected and the POCT senior technologists (CA, FA) adopted operator specific interventions. This strategy was effective in the following month and the improvements were maintained for seven consecutive months. Monthly differences exceeding the CLIA’s criterion decreased significantly [Cl:1.9% (52/2777): K:0.9% (25/2868): Na:0.5% (15/2896)]. This was clearly illustrated with the dot plot by date and the parallel box plots by month. Regression analysis showed that the orthogonal and the OLS models were equivalent. Cl: Orthogonal y=1.7+0.99x, OLS y=12+0.88x. K; Orthogonal y=0.2+1.2x, OLS y=0.1+0.96x. Na: orthogonal y=3+0.98x, OLS y=14+0.9x. Additionally, the POLS model showed a linear relationship within the AMR intervals with few outliers (Cl=11; K=7; Na=9), no influential observations (Hi<0.5) and equality of monthly regression lines (P>0.05). Conclusions The implementation of daily comparisons between patient values as obtained with the i-STAT method and those as obtained by the Laboratory method in the interval of thirty minutes, allowed the identification of individual operators requiring additional training. This strategy ensured reliable performance for eight consecutive months. This study clearly showed that the addition of continuous supervision and training of operators to quality control and quality assurance practices, ensured the interchangeability of patient values as obtained with i-STAT and those as obtained with the Laboratory method. Electronic collection of data and analysis with appropriate statistical software, such as Minitab, was crucial for the implementation of this program.

中文翻译：

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A-331 监测操作员在护理点的熟练程度对于可靠的患者价值至关重要。用 i-STAT® 测定患者血液氯化物、钾和钠测量值的实际示例


背景虽然 i-STAT® 卡式瓶在护理点为医生提供了一系列分析方法，以便及时诊断和干预，但这些方法必须与实验室方法协调一致，以便可靠地检测变化和趋势。通过这个实际示例，我们说明了 i-STAT® 和实验室方法之间常规比较计划的重要性，以检测超出 CLIA 标准并可能具有不良临床影响的分析差异。方法 护士在护理点使用 i-STAT Chem 8 ™ 墨盒（雅培实验室）获得的患者血氯化物 （Cl）、钾 （K） 和钠 （Na） 值，其中每天与实验室方法（两个 cobas 6000®，罗氏诊断）获得的值进行比较使用绿色顶部 BD® 锂肝素管 （Becton Dickinson） 在 i-STAT 测定后 30 分钟内收集。数据以电子方式存储在 RALS™ （RALS Informatics） 中，并传输到 Minitab®（版本 21，Minitab Inc.）统计软件。使用正交和多项式常最小二乘法 （POLS） 回归模型及其图形表示对两种分析方法进行了比较。使用正态性、独立性、异常值 （标准化残差 >|3|） 和有影响力的观测值 （Hi>0.5） 的标准化残差诊断来评估方法的适用性。为了接受差异，采用了 CLIA 的总误差标准。（CI：目标值± 5%;K： 目标值± 0.5 mmol/L;Na：目标值± 4 mmol/L）。结果：在研究的前四个月，超出 CLIA 标准的差异数量是不可接受的。[Cl： 10% （165/1564）;K：7% （109/1593）;钠：4% （66/1586）]。 这些差异在整个分析范围 （AMR） 中都发生。因此，怀疑操作员的技术，POCT 高级技术人员 （CA、FA） 采用了操作员特定的干预措施。该策略在下个月生效，并且连续 7 个月保持改进。超过CLIA标准的月度差异显著减少[Cl：1.9% （52/2777）：K：0.9% （25/2868）：Na：0.5% （15/2896）]。按日期的点图和按月的平行箱形图清楚地说明了这一点。回归分析表明，正交模型和 OLS 模型是等效的。Cl：正交 y=1.7+0.99x，OLS y=12+0.88x。K;正交 y=0.2+1.2x，OLS y=0.1+0.96x。Na：正交 y=3+0.98x，OLS y=14+0.9x。此外，POLS 模型在 AMR 区间内显示出线性关系，几乎没有异常值 （Cl=11;K=7;Na=9）、无影响观测值 （Hi<0.5） 和月度回归线相等 （P>0.05）。结论 在 30 分钟的间隔内，对使用 i-STAT 方法获得的患者值和通过实验室方法获得的患者值进行每日比较，可以识别需要额外培训的个体操作员。这一策略确保了连续八个月的良好表现。这项研究清楚地表明，在质量控制和质量保证实践中增加对操作员的持续监督和培训，确保了使用 i-STAT 获得的患者值和通过实验室方法获得的患者值的可互换性。使用适当的统计软件（如 Minitab）以电子方式收集数据和分析对于该计划的实施至关重要。