凝血酶原时间测定标准化在人工瓣膜替换术后抗凝治疗中的作用

为探讨不同来源组织凝血活酶对凝血酶原时间（PT）测定结果的影响以及PT标准化在指导抗凝治疗中的作用，采用两种国产组织凝血活酶测定20例人工机械瓣膜替换术患者PT及凝血因子X活性。结果显示：抗凝期间凝血因子X活性得到有效抑制，术后第7、14d两种不同来源试剂测得凝血酶原时间比值（PTR）存在差异。提示用PTR指导抗凝治疗存在一定危险性，而将国际标准化比率作为抗凝治疗的监测指标有助于安全、有效地指导用药。

Role of Standardization of the Prothrombin Time in Monitoring Anticoagulant Therapy After Mechanical Prosthetic Valve Replacement

To evaluate the effects of thromboplastins from different sources on the prothrombin time (PT) test and the role of standardization of PT in monitoring oral anticoagulant therapy, PT assay was performed by using two kinds of homemade thromboplastins (one without providing information on the International Sensitivity Index, ISI, and the other with an ISI of 1. 2) and factor X determined before operation and on postoperative day 4, 7, and 14 in 20 patients with mechanical prosthetic heart valve who were treated with warfarin. The results showed that the activity of factor X was limited effectively during maintenance anticoagulant therapy, but the difference between prothrombin time ratios determined using different reagents existed on postoperative day 7 and 14. The present study suggests that reliance on prothrombin time ratio (PTR) to adjust anticoagulation can cause significant errors and International Normalized Ratio (INR) is of great importance to ensure clinical efficacy and safety of oral anticoagulant therapy in patients with mechanical prosthetic heart valves.