Abstract：
BACKGROUND: Thromboelastogram testing is increasingly being used to manage patients with massive bleeding. An earlier study found that the test results were influenced by the hematocrit (Hct) and platelet (PLT) concentrations. This study sought to determine if these factors confounded the results of a different manufacturer\'s thromboelastography testing.
METHODS: Using freshly collected whole blood from volunteers and stored red blood cells (RBC) and plasma, the whole blood was manipulated to achieve different Hct values and PLT concentrations. Each reconstituted whole blood sample was tested in triplicate on the ROTEM Delta device and the ExTEM results were recorded.
RESULTS: Many of the ExTEM results varied according to the Hct and PLT concentration. In particular, the ExTEM clot formation time (CFT) was abnormally long when the Hct was 45% and the PLT concentration was ≤75 × 109/L, normalizing only when the PLT count was ≥100 × 109/L. CFT samples with Hct 25% and 35% were also abnormal with low PLT concentrations but normalized at lower PLT concentrations compared to the Hct 45% samples. The ExTEM angle also demonstrated abnormal results when the Hct was 45% and the PLT concentration was ≤50 × 109/L. The ExTEM A10 and maximum clot firmness (MCF) tests tended to also be abnormal when the Hct was between 25% and 45% and the platelet concentrations were below 75 × 109/L.
CONCLUSIONS: While thromboelastogram testing is gaining popularity for managing bleeding patients, clinicians should be aware of these confounding factors when making transfusion decisions based on their results.
METHODS: Using freshly collected whole blood from volunteers and stored red blood cells (RBC) and plasma, the whole blood was manipulated to achieve different Hct values and PLT concentrations. Each reconstituted whole blood sample was tested in triplicate on the ROTEM Delta device and the ExTEM results were recorded.
RESULTS: Many of the ExTEM results varied according to the Hct and PLT concentration. In particular, the ExTEM clot formation time (CFT) was abnormally long when the Hct was 45% and the PLT concentration was ≤75 × 109/L, normalizing only when the PLT count was ≥100 × 109/L. CFT samples with Hct 25% and 35% were also abnormal with low PLT concentrations but normalized at lower PLT concentrations compared to the Hct 45% samples. The ExTEM angle also demonstrated abnormal results when the Hct was 45% and the PLT concentration was ≤50 × 109/L. The ExTEM A10 and maximum clot firmness (MCF) tests tended to also be abnormal when the Hct was between 25% and 45% and the platelet concentrations were below 75 × 109/L.
CONCLUSIONS: While thromboelastogram testing is gaining popularity for managing bleeding patients, clinicians should be aware of these confounding factors when making transfusion decisions based on their results.
摘要：
背景：血栓弹力图检测越来越多地用于治疗大出血患者。较早的研究发现，测试结果受血细胞比容（Hct）和血小板（PLT）浓度的影响。本研究旨在确定这些因素是否与不同制造商的血栓弹力图检测结果混淆。
方法：使用新鲜采集的志愿者全血和储存的红细胞（RBC）和血浆，对全血进行操作以获得不同的Hct值和PLT浓度.在ROTEMδ装置上一式三份测试每个重构的全血样品,并记录ExTEM结果。
结果：许多ExTEM结果根据Hct和PLT浓度而变化。特别是,当Hct为45％且PLT浓度≤75×109/L时，ExTEM凝块形成时间（CFT）异常长，仅当PLT计数≥100×109/L时进行归一化具有25%和35%的Hct的CFT样品在低PLT浓度下也是异常的,但与45%的Hct样品相比,在较低的PLT浓度下归一化。当Hct为45％且PLT浓度≤50×109/L时，ExTEM角度也显示出异常结果。当Hct在25％至45％之间且血小板浓度低于75×109/L时，ExTEMA10和最大凝块硬度（MCF）测试也趋于异常。
结论：虽然血栓弹力图检测在治疗出血患者方面越来越受欢迎，临床医师在根据结果做出输血决策时,应注意这些混杂因素.
方法：使用新鲜采集的志愿者全血和储存的红细胞（RBC）和血浆，对全血进行操作以获得不同的Hct值和PLT浓度.在ROTEMδ装置上一式三份测试每个重构的全血样品,并记录ExTEM结果。
结果：许多ExTEM结果根据Hct和PLT浓度而变化。特别是,当Hct为45％且PLT浓度≤75×109/L时，ExTEM凝块形成时间（CFT）异常长，仅当PLT计数≥100×109/L时进行归一化具有25%和35%的Hct的CFT样品在低PLT浓度下也是异常的,但与45%的Hct样品相比,在较低的PLT浓度下归一化。当Hct为45％且PLT浓度≤50×109/L时，ExTEM角度也显示出异常结果。当Hct在25％至45％之间且血小板浓度低于75×109/L时，ExTEMA10和最大凝块硬度（MCF）测试也趋于异常。
结论：虽然血栓弹力图检测在治疗出血患者方面越来越受欢迎，临床医师在根据结果做出输血决策时,应注意这些混杂因素.
