Are frequent calibrations enough? A patient-based quality control perspective on blood gas and laboratory analyzers

IF 2.9 3区医学 Q2 MEDICAL LABORATORY TECHNOLOGY

Clinica Chimica Acta Pub Date : 2025-10-10 DOI:10.1016/j.cca.2025.120649

Coskun Cavusoglu

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引用次数: 0

Abstract

Objectives

Quality control (QC) plays a fundamental role in clinical laboratories by safeguarding the accuracy and reliability of test outcomes. Conventional QC materials often fail to fully reflect patient sample behavior due to matrix differences, leading to non-commutability. Patient-Based Quality Control (PBQC), which evaluates real patient data, offers greater sensitivity for detecting analytical errors. Blood gas analyzers in point-of-care settings rely on frequent automatic calibrations, whereas central laboratory analyzers use operator-driven calibrations. This study compared their analytical performance using PBQC metrics.

Methods

In this retrospective study, patient results for glucose, sodium (Na), and hemoglobin (Hgb) were collected over a three-month period (May–July) at Ümraniye Training and Research Hospital. Data were obtained from central laboratory analyzers (Roche COBAS 8000, Mindray BC6000) and a point-of-care blood gas analyzer (Siemens Rapidpoint 500). A total of 112,898 results were included following the application of three truncation methods based on Reference Interval (RI), RCVG, and the Outlier Q test. PBQC analysis was conducted using Exponentially Weighted Moving Average (EWMA) charts (λ = 0.05) with evaluation of False Positive Flag Rate and average number of patient results before error detection (ANPed), in accordance with IFCC recommendations. Probability of error detection (Ped) values were also calculated from IQC data.

Results

PBQC analysis demonstrated that the False Positive Flag Rate was consistently lower in central laboratory analyzers compared to the blood gas analyzer. ANPed values were low in both device types, indicating effective error detection capability. Ped values reached 1.00 for glucose in the Rapidpoint analyzer and sodium in the COBAS 8000, whereas lower Ped values were observed for Rapidpoint sodium and hemoglobin.

Conclusions

PBQC provides an effective complement to conventional QC, enabling early detection of analytical deviations in both central laboratory and point-of-care analyzers. Our findings show that blood gas analyzers, despite frequent automatic calibrations, generate more false positive alerts, whereas central laboratory analyzers demonstrate more stable performance. We propose that PBQC-based algorithms be integrated into blood gas analyzer software, allowing calibrations to be triggered by observed deviations rather than fixed time intervals. Such an approach would enhance analytical reliability and improve quality assurance in point-of-care testing.

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频繁的校准是否足够？基于患者的血气和实验室分析仪的质量控制观点。

目的：质量控制（QC）在临床实验室中起着至关重要的作用，保证了检测结果的准确性和可靠性。由于基质的差异，传统的QC材料往往不能充分反映患者样品的行为，导致不可交换性。以患者为基础的质量控制（PBQC）评估真实的患者数据，为检测分析错误提供了更高的灵敏度。医疗点环境中的血气分析仪依赖于频繁的自动校准，而中心实验室分析仪则使用操作员驱动的校准。本研究使用PBQC指标比较了他们的分析性能。方法：在这项回顾性研究中，在Ümraniye培训与研究医院收集了三个月（5 - 7月）的患者葡萄糖、钠（Na）和血红蛋白（Hgb）结果。数据来自中心实验室分析仪（罗氏COBAS 8000，迈瑞BC6000）和护理点血气分析仪（西门子Rapidpoint 500）。采用基于参考区间（RI）、RCVG和Outlier Q检验的三种截断方法，共纳入112,898个结果。采用指数加权移动平均（EWMA）图（λ = 0.05）进行PBQC分析，评估假阳性标志率（False Positive Flag Rate）和错误检测前平均患者结果数（ANPed），符合IFCC建议。误差检测概率（Ped）值也由IQC数据计算。结果：PBQC分析表明，与血气分析仪相比，中心实验室分析仪的假阳性标志率始终较低。两种设备类型的ANPed值都很低，表明有效的错误检测能力。Rapidpoint分析仪中的葡萄糖和COBAS 8000中的钠的Ped值达到1.00，而Rapidpoint分析仪中的钠和血红蛋白的Ped值较低。结论：PBQC为传统QC提供了有效的补充，使中心实验室和护理点分析仪能够早期发现分析偏差。我们的研究结果表明，尽管血气分析仪经常进行自动校准，但会产生更多的误报警报，而中央实验室分析仪则表现出更稳定的性能。我们建议将基于pbqc的算法集成到血气分析仪软件中，允许根据观察到的偏差触发校准，而不是固定的时间间隔。这种方法将提高分析的可靠性，并改善即时检测的质量保证。

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来源期刊

Clinica Chimica Acta 医学-医学实验技术

CiteScore

10.10

自引率

2.00%

发文量

1268

审稿时长

23 days

期刊介绍： The Official Journal of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Clinica Chimica Acta is a high-quality journal which publishes original Research Communications in the field of clinical chemistry and laboratory medicine, defined as the diagnostic application of chemistry, biochemistry, immunochemistry, biochemical aspects of hematology, toxicology, and molecular biology to the study of human disease in body fluids and cells. The objective of the journal is to publish novel information leading to a better understanding of biological mechanisms of human diseases, their prevention, diagnosis, and patient management. Reports of an applied clinical character are also welcome. Papers concerned with normal metabolic processes or with constituents of normal cells or body fluids, such as reports of experimental or clinical studies in animals, are only considered when they are clearly and directly relevant to human disease. Evaluation of commercial products have a low priority for publication, unless they are novel or represent a technological breakthrough. Studies dealing with effects of drugs and natural products and studies dealing with the redox status in various diseases are not within the journal''s scope. Development and evaluation of novel analytical methodologies where applicable to diagnostic clinical chemistry and laboratory medicine, including point-of-care testing, and topics on laboratory management and informatics will also be considered. Studies focused on emerging diagnostic technologies and (big) data analysis procedures including digitalization, mobile Health, and artificial Intelligence applied to Laboratory Medicine are also of interest.