Delianu Carmen, Moscalu Mihaela, Ghizdovat Vlad, Hurjui Loredana L, Hurjui Ion, Tărniceriu Cristina C, Foia Liliana
Clin Lab. 2020 Sep 1;66(9). doi: 10.7754/Clin.Lab.2020.191105.
The selection and rejection of non-conforming coagulation specimens is essential in safeguarding quality management in hemostasis laboratories that provide routine testing for bleeding and thrombotic disorders. In order to increase quality, it is important to reduce pre-analytical errors that generally account for 60 - 70% of total laboratory failure. The accidental presence of clots in vitro, in the pre-analytical phase of the coagulation, is a reason for coagulation specimen rejection, given that the reliability of test results can be adversely compromised. This study aimed to ascertain the effect of clots identified in the post-analytical phase within the blood sample sediments upon standard laboratory tests such as PT (prothrombin time) and APTT (activated partial thromboplastin time).
From a total of 24,670 coagulation specimens gathered and prospectively collected and analyzed at the Haematology Laboratory of the ˮSf. Spiridonˮ Emergency County Hospital Iasi, Romania, during four months, 671 were identified with clot. Of the coagulated samples, 153 (22.80%) were considered for this study, including those specimens pinpointed with sediment clot through a post-analytical new reverification procedure.
The comparative study of the PT and APTT results obtained based on the samples identified with sediment clots in relation to the actual results recorded after the repetition of the sampling, pointed out 43.93% false results for PT1 test, with a significant difference between the variances of the values at the two evaluated moments (t = 2.961, p = 0.0037). The pattern was congruent in the case of the APTT test as well, exhibiting 69.04% false results, for which the variances of values at the two evaluated moments displayed significant differences (t = 2.208, p = 0.0306). In both of the cases significantly lower mean values were noted in the second determination of PT (PT1: 33.1 ± 39.6 vs. PT2: 25.8 ± 30.5) and APTT (APTT1: 42.8 ± 42.7 vs. APTT2: 38.1 ± 26.1. Results are important as they highlight the actual interference between the clot in the erythrocyte sediment and the evaluation of the patient's hemostasis.
Our results confirm that the presence of clots in the erythrocyte sediment, with no identification prior to centrifugation, significantly affect the PT and APTT analysis, their accurate results being critical for the proper diagnosis and monitoring of anticoagulant therapy.
在为出血和血栓性疾病提供常规检测的止血实验室中，选择和拒收不合格的凝血标本对于保障质量管理至关重要。为了提高质量，减少通常占实验室总故障60 - 70%的分析前误差非常重要。在凝血分析前阶段，体外意外出现凝块是凝血标本被拒收的一个原因，因为检测结果的可靠性可能会受到不利影响。本研究旨在确定在血液样本沉淀物的分析后阶段发现的凝块对标准实验室检测（如凝血酶原时间（PT）和活化部分凝血活酶时间（APTT））的影响。
在罗马尼亚雅西“圣斯皮里东”县急救医院血液学实验室，在四个月内前瞻性收集并分析了总共24,670份凝血标本，其中671份被鉴定有凝块。在这些凝血样本中，153份（22.80%）被纳入本研究，包括那些通过分析后新的重新验证程序确定有沉淀物凝块的标本。
基于鉴定有沉淀物凝块的样本获得的PT和APTT结果与重复采样后记录的实际结果的对比研究指出，PT1检测有43.93%的错误结果，两个评估时刻的值的方差之间存在显著差异（t = 2.961，p = 0.0037）。APTT检测情况也是如此，有69.04%的错误结果，两个评估时刻的值的方差显示出显著差异（t = 2.208, p = 0.0306）。在这两种情况下，PT第二次测定（PT1：33.1 ± 39.6 vs. PT2：25.8 ± 30.5）和APTT（APTT1：42.8 ± 42.7 vs. APTT2：38.1 ± 26.1）的平均值均显著较低。这些结果很重要，因为它们突出了红细胞沉淀物中的凝块与患者止血评估之间的实际干扰。
我们的结果证实，红细胞沉淀物中存在凝块且在离心前未被识别，会显著影响PT和APTT分析，其准确结果对于正确诊断和监测抗凝治疗至关重要。
