Ereth M H, Nuttall G A, Santrach P J, Klindworth J T, Oliver W C, Schaff H V
Department of Anesthesiology, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
Anesthesiology. 1998 Apr;88(4):962-9. doi: 10.1097/00000542-199804000-00016.
Platelet dysfunction is one of several major causes of bleeding after cardiopulmonary bypass. A timely, simple, point-of-care determinant of platelet function recently became available for clinical use. Adding platelet-activating factor to conventional activated clotting time methods (platelet-activated clotting test [PACT]) produces rapid results (<15 min) and may yield a measure of platelet responsiveness and whole-blood procoagulant activity.
Blood samples were drawn from 100 patients after cardiac surgery on their arrival in the intensive care unit for PACT, platelet count, prothrombin time (PT), and activated partial thromboplastin time (aPTT). Cumulative blood loss at 4, 8, and 12 h after arrival in the intensive care unit and perioperative transfusion requirements were quantitated. Coagulation tests and mediastinal blood loss were compared using the Spearman rank test and Pearson correlation. The sensitivity and specificity of the laboratory tests for predicting blood loss were analyzed using the receiver operating characteristic method.
The PT was the only test that correlated with blood loss at 4, 8, and 12 h. The PACT did not correlate with blood loss at 4, 8, or 12 h, nor did the PACT correlate with the PT or the aPTT. The sensitivity and specificity of the PACT were less than those of the PT in predicting blood loss. Only the PT correlated with platelet and fresh frozen plasma transfusion.
The PT correlated with blood loss and transfusion requirements and was superior to PACT, aPTT, and platelet count for predicting excessive blood loss after cardiopulmonary bypass.
血小板功能障碍是体外循环后出血的几个主要原因之一。一种及时、简单的床旁血小板功能测定方法最近已可供临床使用。在传统的活化凝血时间方法（血小板活化凝血试验[PACT]）中加入血小板活化因子可快速得出结果（<15分钟），并可能得出血小板反应性和全血促凝血活性的测量值。
在100例心脏手术后患者进入重症监护病房时采集血样，进行PACT、血小板计数、凝血酶原时间（PT）和活化部分凝血活酶时间（aPTT）检测。对进入重症监护病房后4、8和12小时的累计失血量以及围手术期输血需求进行定量分析。使用Spearman秩和检验和Pearson相关性分析比较凝血试验和纵隔失血量。采用受试者工作特征法分析实验室检测预测失血量的敏感性和特异性。
PT是唯一与4、8和12小时失血量相关的检测指标。PACT与4、8或12小时失血量无关，也与PT或aPTT无关。在预测失血量方面，PACT的敏感性和特异性低于PT。只有PT与血小板和新鲜冰冻血浆输注相关。
PT与失血量和输血需求相关，在预测体外循环后过度失血方面优于PACT、aPTT和血小板计数。
