凝血酶原时间标准化及干扰因素的研究

目的探讨凝血酶原时间(PT)测定的影响因素.方法将凝血仪检测PT时的凝血活酶视为未知ISI值的凝血活酶,用已知ISI的凝血活酶对其进行标定,比较仪器ISI标定前后检测的INR结果.结果 ACLFUTURA PLUS凝血仪对ISI值为1.35(厂家的手工法值)的凝血活酶ISI标定值为1.27;ISI值校正前仪器测定的INR值与手工法有较大的变异(Cv值为13.4%,P＜0.01),ISI校正后仪器测定的INR值与手工法变异系数变小(Cv值为4.8%,P＞0.05).自动化凝血仪对手工标定的凝血活酶ISI值产生影响.枸橼酸钠与血液1:9的抗凝关系是最佳比例,但应注意红细胞比积的影响,检测时间在4 h为宜,血红蛋白、肝素、胆红素血脂对其有干扰.结论注意干扰物对PT测定的影响;用自动化仪器进行PT国际标准化测定时须用校正后的系统独立的ISI计算INR值,以克服仪器本身的误差对INR系统的影响.

Effect of Interfering Substances on Prothrombin Time and Standardization

objective To observe the effect of interfering substances and thromboplastin on prothrombin time(PT).Methods ISI values are corrected on the coagulometer systems with unknown ISI values of thromboplastin to compare INR result of corrected and no corrected ISI values on the coagulometer systems and manual method.Results 1.35 ISI (IL Manual assay) of tissue thromboplastin may corrected 1.27 on coagulometer systems, There are significant differences in INR values between instrument method and manual method before ISI values are corrected(CV =13.4% P <0.01)and there are no significant differences after corrected ISI values.Auto coagulometer system affected ISI values which measured by manual method(CV=4.8% P >0.05). It is better to draw nine parts freshly venous blood into one part trisodium citrate and to measure in 4 hour, PT result are affected by excess heparin,hemoglobin,triglyceride,bilirubin in the plasma assayed.Conclusion Caution the effect of interfering substances on PT, INR values of prothrombin time are measured by using coagulometer systems with corrected ISI values that may eliminate the effect of instrumentation error itself on INR system.