Abstract

Around 1.5% of the total clinical biochemistry tests performed in laboratories are affected by preanalytical errors. Large, automated chemistry analysers prevent errors and interference by using control systems such as spectrophotometric measurements to evaluate serum indices, i.e. haemolysis (H), icterus (I), and lipemia/turbidity (L). However, still preanalytical errors can remain undetected. Our laboratory experienced an incident caused by laboratory-induced preanalytical errors, where approximately 100 sedimented lithium heparin samples bypassed centrifugation and entered our automated analyser. Based on index results, we investigated the possibility of using turbidimetry measurement, as a mean to prevent analysis on uncentrifuged sedimented whole blood. 14078 L-indices from 8 days in August 2019 were extracted from the middleware and used to develop and evaluate stop rules. Similarly, a one-day validation dataset was identified in December 2020 and used for an independent validation. Three different types of stop rules were evaluated: (1) A single L-index result above a cut-off; (2) A sequence of an L-index results above a cut-off; (3) A simple moving average of n results above a cut-off. A stop rule using 3 consecutive L-indices of 40–60 was found to be superior. However, practical implementation in the instrument middleware on a Roche Cobas 8000 only allowed a simple moving average of 110 (n = 5). This rule was found to be able to identify and stop sedimented whole blood analysis. Additionally, the rule has minimal impact on daily routine production in the laboratory.

摘要

在实验室进行的全部临床生化测试中，约有 1.5% 受到分析前错误的影响。大型自动化化学分析仪通过使用控制系统（例如分光光度测量）来评估血清指数（即溶血 (H)、黄疸 (I) 和脂血症/浊度 (L)）来防止错误和干扰。然而，分析前错误仍然可能未被检测到。我们的实验室经历了一次由实验室引起的分析前错误引起的事件，其中大约 100 个沉淀的肝素锂样品绕过离心进入我们的自动分析仪。根据指数结果，我们研究了使用比浊法测量的可能性，作为防止对未离心沉淀的全血进行分析的手段。从中间件中提取了 2019 年 8 月 8 天的 14078 个 L 指数，用于开发和评估停止规则。同样，在 2020 年 12 月确定了一个为期一天的验证数据集，并用于独立验证。评估了三种不同类型的停止规则： (1) 单个 L 指数结果高于截止值；(2) 一系列 L-index 结果高于截止值；(3) n 的简单移动平均线结果高于截止值。发现使用 40-60 的 3 个连续 L 指数的停止规则更好。然而，在 Roche Cobas 8000 仪器中间件中的实际实现只允许 110 ( (1) 单个 L 指数结果高于临界值；(2) 一系列 L-index 结果高于截止值；(3) n 的简单移动平均线结果高于截止值。发现使用 40-60 的 3 个连续 L 指数的停止规则更好。然而，在 Roche Cobas 8000 仪器中间件中的实际实现只允许 110 ( (1) 单个 L 指数结果高于临界值；(2) 一系列 L-index 结果高于截止值；(3) n 的简单移动平均线结果高于截止值。发现使用 40-60 的 3 个连续 L 指数的停止规则更好。然而，在 Roche Cobas 8000 仪器中间件中的实际实现只允许 110 (n  = 5)。发现该规则能够识别和停止沉淀的全血分析。此外，该规则对实验室日常生产的影响很小。