血浆D-二聚体对疑似肺栓塞患者诊断价值的研究

目的：探讨血浆 D-二聚体对对疑似肺栓塞患者的诊断价值。方法采用自动化免疫比浊法测定患者血浆D-二聚体水平。统计分析血浆D-二聚体诊断肺栓塞的敏感性、特异性、阴性及阳性预测值，并绘制ROC曲线以评价其诊断价值并对D-二聚体阴性排除肺栓塞价值进行分析。结果在317例疑似肺栓塞患者中D-二聚体＜500μg/L的患者73例，其中6例被诊断为肺栓塞。D-二聚体对肺栓塞的诊断的敏感性为95.86%（95%CI：91.27%～98.08%），特异性为38.95%（95%CI：31.98%～41.41%），阴性预测值为91.78%（95%CI：83.21%～96.18%），阳性预测值为56.97%（95%CI：50.69%～63.02%），诊断准确性为64.98%（95%CI：59.58%～70.03%）。ROC曲线下面积为0.674（95%CI：0.615～0.733）。结论 D-二聚体对肺栓塞的诊断具有较高的敏感性，阴性排除肺栓塞的准确性较高，但仍可受患者年龄、测试方法等的影响。

Diagnostic value of plasma D-dimer in patients with suspected pulmonary embolism

Objective To study the diagnostic value of D-Dimer for patients suspected of pulmonary embolism（PE）. Methods D-dimer levels were determined by rapid quantitative automated turbidimetric immunoassay. To evaluate the diagnostic performances of the D-dimer testing, sensitivity, specificity, negative predictive values, positive predictive values, accuracy and their 95%confidence intervals （95%CI） were calculated according to standard methods for proportions. The ROC curve analysis was also performed. Results Among the 73 patients out of 352 （25.3%） suspected PE patients that had a D-dimer level below 500 ng/ml, six patients had a confirmed PE according to the diagnosis strategy. Sensitivity of D-dimer assays reached 95.86% （95% CI：91.27%-98.08%） and specificity was 38.95% （95% CI： 31.98%-41.41%）; negative predictive value reached 91.78% （95% CI： 83.21%-96.18%） and positive predictive value was 56.97% （95% CI： 50.69%-63.02%）; the accuracy was 64.98%（95% CI： 59.58%-70.03%）. The under area of ROC was 0.674（95% CI： 0.615-0.733）. Conclusion The plasma D-dimer has high sensitivity in diagnosis of PE. But the age of patients, test method of D-dimer etc. may affect the sensitivity.