Tabuchi N, Tigchelaar I, van Oeveren W
Dept of Blood Interaction Research, Cardiopulmonary Surgery, University Hospital, Groningen, The Netherlands.
Semin Thromb Hemost. 1995;21 Suppl 2:66-70. doi: 10.1055/s-0032-1313605.
The contribution of platelet dysfunction to the impaired hemostasis after cardiac surgery remains to be established, because there is no sensitive method to assess platelet function. Measurement of the shear-induced pathway of platelet function, an important mechanism in inducing hemostasis, became possible by a novel shear-inducing technique, the in-vitro bleeding test (Thrombostat 4000). By using this test, the changes in platelet function during cardiopulmonary bypass and their contribution to hemostasis were investigated in patients undergoing cardiac surgery. Platelet function is quickly impaired shortly after the start of cardiopulmonary bypass, and partly recovered at the end of cardiopulmonary bypass. The function of aspirin-treated platelets is more severely affected than of nonaspirin platelets during cardiopulmonary bypass. Furthermore, the degree of platelet dysfunction at the end of the operation, but neither the platelet number nor the activated clotting time, was significantly correlated with blood loss from the chest drain after cardiac surgery. These results indicate the significant and variable effects of cardiopulmonary bypass on the shear-induced pathway of platelet function. Moreover, the impairment of this function of platelets appears to be a major cause of excessive bleeding in patients after cardiac surgery. Therefore, the routine use of the shear-inducing test seems helpful to make a proper diagnosis and design the therapy for bleeders after cardiac surgery.
血小板功能障碍对心脏手术后止血功能受损的作用仍有待确定，因为目前尚无评估血小板功能的灵敏方法。通过一种新型的剪切诱导技术——体外出血试验（Thrombostat 4000），可以对诱导止血的重要机制即血小板功能的剪切诱导途径进行测量。利用该试验，对接受心脏手术的患者在体外循环期间血小板功能的变化及其对止血的作用进行了研究。体外循环开始后不久，血小板功能迅速受损，并在体外循环结束时部分恢复。在体外循环期间，服用阿司匹林的血小板功能比未服用阿司匹林的血小板受到的影响更严重。此外，手术结束时血小板功能障碍的程度，而非血小板数量或活化凝血时间，与心脏手术后胸腔引流的失血量显著相关。这些结果表明体外循环对血小板功能的剪切诱导途径有显著且多变的影响。此外，血小板的这种功能受损似乎是心脏手术后患者出血过多的主要原因。因此，常规使用剪切诱导试验似乎有助于对心脏手术后出血患者进行正确诊断并设计治疗方案。
