D-二聚体对髋关节和膝关节置换术后并发深静脉血栓的临界值及诊断意义

Discussion the cut-off value and significance of D-dimer in the diagnosis of deep vein thrombosis after total hip and knee replacement

目的利用受试者工作特征曲线(ROC)确定D-二聚体在我院骨科全髋关节置换术和膝关节置换术后发生下肢深静脉血栓(DVT)的诊断阈值(cut off),并评价其临床意义。方法收集本院2014年1月至2015年3月进行全髋关节置换术和膝关节置换术患者255例,术后发生下肢深静脉血栓42例,未发生者213例,并以健康体检者200例作为对照。以免疫比浊法检测D-二聚体值,应用统计软件进行分析,绘制ROC曲线。结果根据ROC曲线,D-二聚体用于髋关节、膝关节置换术后并发DVT的最佳诊断阈值为1.65mg/L(灵敏度为66.7%,特异度为79.1%,阳性似然比为3.19.)。结论 1.65 mg/L是本实验室D-二聚体诊断髋关节、膝关节置换术后并发DVT的合适临界值,能提高临床诊断效率。

Objective Using ROC curve to determine the cut-off value of D-dimer in the diagnosis of deep vein thrombosis and evaluate its clinical significance. Methods Blood samples of 255 patients undergoing total hip replacement and knee joint replacement were collected, of which 42 cases got DVT and 213 cases got no DVT. And 200 healthy people were collected as control group. All these blood samples were measured for D-dimer content by immunotur-bidimetric methods, then ROC curve was drawn and the Cut-off value was determined by statistical software. Results The plasma level of D-dimer were significantly higher in patients with DVT than that in patients without DVT （P〈0.05） and this level in patients without DVT were significantly higher than that in healthy subjects （P〈0.05）. The area under the curve was 0.796 for DVT. The appropriate cut-off value of D-dimer for the patients with DVT was 1.65mg / L（sensitivity was 66.7%,specificity was 79.1%, and positive likelihood Ratio was 3.19）. Conclusion The appropriate cut-offvalue of D-dimer in the local laboratory is 1.65mg/L, this value detection would improve the efficiency of the diagnosis of deep vein thrombosis.