Department of Cardiovascular Sciences, Academic Unit of Emergency Medicine, University of Leicester, Leicester, Leicestershire, UK
Department of Cardiovascular Sciences, Academic Unit of Emergency Medicine, University of Leicester, Leicester, Leicestershire, UK.
Emerg Med J. 2020 Mar;37(3):135-140. doi: 10.1136/emermed-2019-209181. Epub 2020 Jan 30.
To understand more about the individual variation in the time course of fibrinolysis following major injury and to assess the potential for stratification of trauma patients for tranexamic acid (TXA) therapy.
A historical dataset (from 2004) was used, consisting of samples from 52 injured patients attended by a medical prehospital system. Blood samples were taken at the incident scene, on arrival in the emergency department, 2.5 hours after hospital arrival and 5 hours after hospital arrival. From the study database, we extracted values for tissue-type plasminogen activator (tPA; an activator of fibrinolysis), one of the plasminogen activator inhibitors (PAI-1; as a natural inhibitor of fibrinolysis) and D-dimer (as a marker of the extent of fibrinolysis).
The changes over time in median tPA and PAI-1 were mirror images, with initial high tPA levels which then rapidly decreased and low initial PAI-1 levels which slowly increased. There were high levels of fibrinolytic activity (D-dimer) throughout. This pattern was present in patients across a broad range of injury severities.
After major trauma, there seems to be an early 'antifibrinolytic gap' with the natural antifibrinolytic system lagging several hours behind the natural profibrinolytics. An early dose of exogenous antifibrinolytic (TXA) might have its effect by filling this gap. The finding that tPA and subsequent clot breakdown (illustrated by D-dimer formation) are raised in a broad range of patients, with little correlation between the initial fibrinolytic response and markers of injury severity, may be the reason that TXA is effective across a broad range of injured patients.
了解重大损伤后纤溶时间过程中的个体差异，并评估创伤患者接受氨甲环酸（TXA）治疗的分层潜力。
使用历史数据集（来自 2004 年），该数据集由医疗院前系统收治的 52 名受伤患者的样本组成。在事件现场、到达急诊部时、到达医院 2.5 小时后和到达医院 5 小时后采集血液样本。从研究数据库中，我们提取了组织型纤溶酶原激活物（tPA；纤溶的激活剂）、纤溶酶原激活物抑制剂之一（PAI-1；作为纤溶的天然抑制剂）和 D-二聚体（作为纤溶程度的标志物）的值。
tPA 和 PAI-1 的中位数随时间的变化呈镜像，初始 tPA 水平较高，然后迅速下降，初始 PAI-1 水平较低，然后缓慢增加。纤溶活性（D-二聚体）水平一直很高。这种模式存在于各种严重程度的损伤患者中。
在严重创伤后，似乎存在早期的“抗纤溶间隙”，天然抗纤溶系统滞后数小时。早期给予外源性抗纤溶剂（TXA）可能通过填补这一空白发挥作用。tPA 和随后的血栓分解（通过 D-二聚体形成来表示）在广泛的患者中升高，初始纤溶反应与损伤严重程度标志物之间几乎没有相关性，这可能是 TXA 在广泛的受伤患者中有效的原因。
