Introduction: While previous studies have shown a significant impact of extreme hypo- and hyperthermia on coagulation, effects of much more frequently occurring perioperative mild hypothermia are largely unknown. This study therefore aimed to analyze the effects of mild hypothermia using rotational thromboelastometry in vitro. Materials and Methods: Twelve healthy volunteers were included in this study. Standard thromboelastometric tests (EXTEM, INTEM, FIBTEM) were used to evaluate coagulation in vitro at 39, 37, 35.5, 35, and 33°C. Beyond standard thromboelastometric tests, we also evaluated the effects of mild hypothermia on the TPA-test (ClotPro, Enicor GmbH, Munich, Germany), a new test which aims to detect fibrinolytic capacity by adding tissue plasminogen activator to the sample. Data are presented as the median with 25/75th percentiles. Results: Extrinsically activated coagulation (measured by EXTEM) showed a significant increase in clot formation time (CFT; 37°C: 90 s [81/105] vs. 35°C: 109 s [99/126]; p = 0.0002), while maximum clot firmness (MCF) was not significantly reduced. Intrinsically activated coagulation (measured by INTEM) also showed a significant increase in CFT (37°C: 80 s [72/88] vs. 35°C: 94 s [86/109]; p = 0.0002) without significant effects on MCF. Mild hypothermia significantly increased both the lysis onset time (136 s [132/151; 37°C] vs. 162 s [141/228; 35°C], p = 0.0223) and lysis time (208 s [184/297; 37°C] vs. 249 s [215/358; 35°C]; p = 0.0259). Conclusion: This demonstrates that even under mild hypothermia coagulation is significantly altered in vitro. Perioperative temperature monitoring and management are greatly important and can help to prevent mild hypothermia and its adverse effects. Further investigation and in vivo testing of coagulation under mild hypothermia is needed.
Transfus Med Hemother

中文翻译：

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血栓弹力图评估轻度低温下的凝血

简介：虽然以前的研究表明极端低温和高温对凝血有显着影响，但更频繁发生的围手术期亚低温的影响在很大程度上是未知的。因此，本研究旨在使用体外旋转血栓弹力图分析亚低温的影响。材料和方法：这项研究包括12名健康志愿者。使用标准血栓弹力测试（EXTEM、INTEM、FIBTEM）在 39、37、35.5、35 和 33°C 下评估体外凝血。除了标准血栓弹力测试外，我们还评估了亚低温对 TPA 测试（ClotPro，Enicor GmbH，慕尼黑，德国）的影响，这是一项旨在通过向样本中添加组织纤溶酶原激活剂来检测纤溶能力的新测试。数据以 25/75 百分位数的中位数表示。结果：外源性凝血（通过 EXTEM 测量）显示凝块形成时间显着增加（CFT；37°C：90 秒 [81/105] 对比 35°C：109 秒 [99/126]；p= 0.0002)，而最大凝块硬度 (MCF) 没有显着降低。内在活化凝血（由 INTEM 测量）也显示 CFT 显着增加（37°C：80 秒 [72/88] 与 35°C：94 秒 [86/109]；p = 0.0002）对 MCF 没有显着影响. 轻度低温显着增加了裂解开始时间（136 s [132/151; 37°C] vs. 162 s [141/228; 35°C], p = 0.0223）和裂解时间（208 s [184/297; 37°C] 与 249 秒 [215/358；35°C]；p = 0.0259）。结论：这表明，即使在温和低温下，体外凝血也会发生显着变化。围手术期体温监测和管理非常重要，有助于预防亚低温及其不良反应。需要对亚低温下的凝血进行进一步研究和体内测试。
Transfus Med Hemother