凝血试验真空管"死腔"所致 APTT、PF4偏差探讨

目的　探讨“有死腔”凝血试验管收集的血样进行血小板功能和肝素治疗患者APTT结果的偏差及机制。方法　将 2 0例肝素治疗心肌梗死患者血液分别收集在无或能形成死腔的采血管中 ,分别进行APTT和PF4检测。结果　“有死腔”的采血管使7例患者APTT结果缩短 ,PF4活性增强。结论　采血管死腔增加了血小板与管壁或死腔气体的接触而激活血小板 ,释放PF4并中和肝素 ,造成APTT负偏差。建议进行血小板功能试验或APTT用于肝素治疗监测时使用“无死腔”真空采血管

Analysis for errors caused by dead space of coagulation vacuum tubes in APTT and PF4 tests

Objective To analyze the errors as well as its reasons in APTT test caused by dead space of coagulation vacuum tubes which are used in clinic for sample collection from the patients during heparin therapy to monitor platelet function and level of heparin. Methods Blood samples from patients with myocardial infaction who were receiving heparin therapy were collected into two kinds of coagulation vaccum tubes with or without dead space,and APTT and PF4 factor were detected. Results Elevated PF4 factor level and shortened APTT were found in 7 of 32 blood samples in the tubes with dead space.Conclusion The dead space in coagulation vacuum tube increases the chance of interplay between platelet and dead space air or the interior wall of the tube, which leads to the activation of platelet and release of PF4 factor. As PF4 factor prohibit the action of heparin APTT is shortened and minus error is formed.It is suggested that the coagulation vacuum tubes without dead space should be used in monitoring the heparin therapy.