Culliford A T, Gitel S N, Starr N, Thomas S T, Baumann F G, Wessler S, Spencer F C
Ann Surg. 1981 Jan;193(1):105-11. doi: 10.1097/00000658-198101000-00017.
The activated clotting time (ACT) with a Hemochron system for determining heparin requirements during cardiopulmonary bypass surgery, (CPB) accompanied by hemodilution and hypothermia was evaluated using plasma heparin levels as a standard. In 28 patients who were administered a standard heparin regimen (300 units/kg prebypass, 8000 units in the pump prime and 100 units/kg hourly during CPB) mean prebypass plasma heparin was 4 units/ml, and ACT was 493 seconds. During CPB mean plasma heparin decreased significantly (p < 0.001) to 3.1 units/ml, whereas mean ACT increased significantly (p < 0.001) to 674 seconds. The mean protamine requirement predicted from ACT was significantly higher (43%) than predicted from plasma heparin levels or actual protamine administered. The ACT neither accurately reflected plasma heparin during CPB nor predicted protamine requirements. The fixed-dose regimen employed, however, prevented both intraoperative thrombosis, assessed clinically in all patients, and clotting on six arterial line filters, as determined by scanning EM, despite wide variations in ACT and plasma heparin levels during surgery.
以血浆肝素水平为标准，对使用Hemochron系统测定体外循环手术（CPB）期间肝素需求量时的活化凝血时间（ACT）进行了评估，该手术伴有血液稀释和低温。在28例接受标准肝素方案（体外循环前300单位/千克，预充液中8000单位，体外循环期间每小时100单位/千克）的患者中，体外循环前血浆肝素平均水平为4单位/毫升，ACT为493秒。体外循环期间，血浆肝素平均水平显著降低（p < 0.001）至3.1单位/毫升，而ACT平均显著升高（p < 0.001）至674秒。根据ACT预测的鱼精蛋白平均需求量显著高于根据血浆肝素水平或实际给予的鱼精蛋白预测的需求量（43%）。ACT在体外循环期间既不能准确反映血浆肝素水平，也不能预测鱼精蛋白需求量。然而，尽管手术期间ACT和血浆肝素水平存在很大差异，但所采用的固定剂量方案可防止所有患者临床评估的术中血栓形成以及扫描电镜测定的六个动脉管路滤器上的凝血。
