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 在护理点监控操作员的熟练程度对于可靠的患者价值至关重要。使用 i-STAT® 测定患者血液中氯、钾和钠被测量的实例


背景 虽然 i-STAT® 试剂盒为医生提供了一系列即时诊断和干预的分析方法，但这些方法必须与实验室方法相协调，以便可靠地检测变化和趋势。通过这个实际例子，我们说明了 i-STAT® 和实验室方法之间的常规比较程序的重要性，以检测超出 CLIA 标准并可能产生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™ 试剂盒（Abbott Laboratories）获得的患者血氯 (Cl)、钾 (K) 和钠 (Na) 值，每天与使用 i-STAT Chem 8™ 试剂盒获得的值进行比较实验室方法（两个 cobas 6000®，Roche Diagnostics）使用绿顶 BD® 肝素锂管（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，并传输至 Minitab®（版本 21，Minitab Inc.）统计软件。使用正交和多项式普通最小二乘 (POLS) 回归模型及其图形表示来比较这两种分析方法。使用标准化残差诊断对正态性、独立性、离群值（标准化残差>|3|）和影响观察值（Hi>0.5）评估该方法的适用性。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±0.5mmol/L；Na：目标值±4mmol/L）。结果 在研究的前四个月中，超过 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)]。 这些差异发生在整个分析范围 (AMR) 中。因此，操作员的技术受到怀疑，POCT 高级技术人员（CA、FA）采取了操作员特定的干预措施。该策略在次月生效，并连续七个月保持改善。超过 CLIA 标准的月度差异显着下降 [Cl:1.9% (52/2777): K:0.9% (25/2868): Na:0.5% (15/2896)]。按日期的点图和按月份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 模型显示 AMR 区间内存在线性关系，很少有异常值 (Cl=11；K=7；Na=9)，没有影响观测值 (Hi<0.5) 且每月回归线相等 (P>0) .05）。结论 每日比较 i-STAT 方法获得的患者值与实验室方法获得的患者值（每隔 30 分钟），从而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可靠性能。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，确保了通过 i-STAT 获得的患者值与通过实验室方法获得的患者值的互换性。使用 Minitab 等适当的统计软件进行电子数据收集和分析对于该计划的实施至关重要。