City University of New York School of Medicine, New York, NY 10031, USA; Department of Anesthesiology, Pain and Perioperative Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
Department of Anesthesiology, Pain and Perioperative Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
Int J Obstet Anesth. 2024 Aug;59:103994. doi: 10.1016/j.ijoa.2024.103994. Epub 2024 Mar 26.
The investigation into the variability of fibrinolysis in obstetric patients is notably limited despite its relevance to postpartum hemorrhage. We investigate an in vitro model of fibrinolysis measured by rotational thromboelastrometry (ROTEM) in maternal blood samples with lysis stimulated by tissue plasminogen activator (tPA).
Written informed consent was obtained from 19 patients at term pregnancy during admission to the labor and delivery unit. Patients who were taking medication affecting coagulation were excluded. Tissue plasminogen activator was added to whole blood samples to a final concentration of 100 or 220 ng/mL prior to ROTEM testing.
The addition of tPA produced high intra-individual fibrinolytic variability for clot firmness and lysis parameters. Patients responded differently to each tPA dose ranging from clot lysis within the range of 0 ng/mL tPA group to complete clot lysis. The coefficient of variation (CV) values for the 220 ng/mL tPA group were: EXTEM MCF 0.510, EXTEM LI30 1.601, FIBTEM MCF 0.349, FIBTEM LI30 2.097. CV values for the 100 ng/mL tPA group were: EXTEM MCF 0.144, EXTEM LI30 1.038, FIBTEM MCF 0.096, FIBTEM LI30 1.238.
We demonstrate a wide range of fibrinolytic response in the obstetric population to exogeneous tPA. We found subgroups of patients that were very responsive to tPA and insensitive to tPA. This study represents a preliminary exploration into classifying the obstetric fibrinolytic phenotypes. Further research will integrate relevant coagulation factors to establish a predictive model for testing susceptibility to lysis that can be applied at the point of care.
尽管纤溶在产后出血中具有相关性，但对产科患者纤溶变异性的研究明显有限。我们通过旋转血栓弹性测定法（ROTEM）检测组织型纤溶酶原激活物（tPA）刺激的纤溶来研究母体血液样本中的体外纤溶模型。
在分娩和分娩病房入院期间，从 19 名足月妊娠患者获得书面知情同意。排除正在服用影响凝血药物的患者。将 tPA 添加到全血样本中，终浓度为 100 或 220ng/mL，然后进行 ROTEM 检测。
tPA 的添加产生了高个体内纤维蛋白溶解的血凝块硬度和纤溶参数的变异性。每个 tPA 剂量的患者反应不同，范围从 0ng/mL tPA 组的血凝块溶解到完全血凝块溶解。220ng/mL tPA 组的变异系数（CV）值为：EXTEM MCF 0.510，EXTEM LI30 1.601，FIBTEM MCF 0.349，FIBTEM LI30 2.097。100ng/mL tPA 组的 CV 值为：EXTEM MCF 0.144，EXTEM LI30 1.038，FIBTEM MCF 0.096，FIBTEM LI30 1.238。
我们证明了产科人群对外源性 tPA 的纤溶反应范围广泛。我们发现了对 tPA 非常敏感和不敏感的患者亚组。这项研究代表了对产科纤溶表型进行分类的初步探索。进一步的研究将整合相关的凝血因子，建立一个用于测试纤溶易感性的预测模型，可以在护理点应用。
