Kawasaki J, Katori N, Taketomi T, Terui K, Tanaka K A
Department of Anesthesiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
Acta Anaesthesiol Scand. 2007 Oct;51(9):1237-44. doi: 10.1111/j.1399-6576.2007.01434.x.
Platelet activation is a critical step in primary hemostasis and clot formation. We tested a hypothesis that platelet stimulating effects of vasoactive agents or platelet agonists could be shown using thrombelastography (TEG) as faster onset or increased clot strength. We further examined if TEG could be modified to evaluate activated platelets as a reversal of anticoagulation in the presence of partial thrombin inhibition.
Blood samples were obtained from 126 non-cardiac surgical patients. Effects of vasoactive agents on TEG and aggregometry were examined using epinephrine, norepinephrine, vasopressin, desmopressin acetate, milrinone and olprinone (Experiment I). Platelet agonists (epinephrine, ADP and collagen) were separately tested on TEG (Experiment II). Effects of platelet agonists (ADP and collagen) on TEG under anticoagulation in the absence or presence of abciximab were studied (Experiment III). We also tested antiplatelet effects of milrinone and olprinone in the presence of anticoagulants on TEG (Experiment IV).
Neither vasoactive agents nor platelet agonists affected TEG or aggregometry results except for milrinone and olprinone on aggregometry (Experiment I, II). Platelet agonists facilitated clotting in the presence of anticoagulants (Experiment III). Abciximab-treated platelets still exhibited procoagulant effects in the presence of heparin, while not in the presence of argatroban (Experiment III). Platelet inhibition on the modified TEG was more extensive with milrinone than olprinone, and it was dose dependent (Experiment IV).
Modified TEG using heparin or argatroban might delineate the procoagulant effects of platelets by adding platelet specific agonist.
血小板活化是初级止血和血栓形成的关键步骤。我们检验了一个假设，即使用血栓弹力图（TEG）可以显示血管活性药物或血小板激动剂对血小板的刺激作用，表现为起效更快或血凝块强度增加。我们进一步研究了是否可以对TEG进行改良，以评估在部分凝血酶抑制情况下作为抗凝逆转的活化血小板。
从126例非心脏手术患者中采集血样。使用肾上腺素、去甲肾上腺素、血管加压素、醋酸去氨加压素、米力农和奥普力农检测血管活性药物对TEG和血小板聚集测定的影响（实验I）。在TEG上分别测试血小板激动剂（肾上腺素、ADP和胶原）（实验II）。研究在不存在或存在阿昔单抗的抗凝情况下血小板激动剂（ADP和胶原）对TEG的影响（实验III）。我们还测试了在抗凝剂存在下米力农和奥普力农对TEG的抗血小板作用（实验IV）。
除米力农和奥普力农对血小板聚集测定有影响外，血管活性药物和血小板激动剂均未影响TEG或血小板聚集测定结果（实验I、II）。在抗凝剂存在的情况下，血小板激动剂促进凝血（实验III）。在肝素存在时，阿昔单抗处理的血小板仍表现出促凝作用，而在阿加曲班存在时则没有（实验III）。米力农对改良TEG的血小板抑制作用比奥普力农更广泛，且呈剂量依赖性（实验IV）。
使用肝素或阿加曲班改良的TEG可能通过添加血小板特异性激动剂来描绘血小板的促凝作用。
