Pre-test Probability Scores D-Dimer And Ultrasonography In The Diagnosis Of Pulmonary Thromboembolism

Objective.To evaluate the diagnostic efficacy of pre-test probability scores,D-Dimer,ultrasonography(including lower extremity compressive ultrasonography and echocardiography) and their combination tests for suspected pulmonary thromboembolism.Method:We collected data of 139 confirmed PTE patients as PTE group and 50 patients who suspected PTE from beginning but excluded PTE after tests as control group,assessed every patient's pre-test probability and recorded the results of D-Dimer,lower extremity compressive ultrasonography and echocardiography.Using ROC curve to evaluate the diagnostic efficacy of pre-test probability scores and ELISA testing D-Dimer for PTE; Calculating epidemiology indexation to determine the confirmed or excluded value of the four tests and their combination tests for suspected PTE.Results:(1)About ROC analysis,the area under curve(AUC) of Wells score was 0.692(95%confidence interval[CI],0.610～0.775),the AUC of Geneva score was 0.709(95%CI, 0.633～0.786).The diagnostic efficacy of the two scores were similar for PTE.Wells score more than 7.5 or Geneva score more than 10 had confirmed value for PTE;(2) The AUC of quantitative Latex test was 0.775(95%CI,0.668-0.881),having moderate diagnostic efficacy for PTE;(3)The sensitivity of high pre-test possibility of Wells and Geneva sore for PTE were 92% and 100%respectively,and specificity of them were 22.6%and 22.3%respectively;(4) Of the four single test,the Youden's index of lower extremity compressive ultrasonography was 0.615, having the highest significance for diagnosing PTE;(5)Using semiquantitative Latex or quantitative Latex to test D-Dimer of all the patients in PTE group and control group,the negative likelihood ratio was 0.3(＞0.1),using quantitative Latex,the negative likelihood ratio was 0.453(＞0.1);Using semiquantitative Latex or quantitative Latex to test D-Dimer of the patients who had low and moderate pre-test probability in PTE group and control group,the negative likelihood ratio was 0.261(＞0.1),using quantitative Latex,the negative likelihood ratio was 0.552(＞0.1).So,excluding acute PTE could not base on negative result whatever the two methods you used to test D-Dimer.(6)Several parallel and series tests could make sensitivity and specificity increase.(7)Of all parallel tests,the Youden's index of high pre-test probability+lower extremity compressive ultrasonography was highest,0.636(sensitivity 85.6%,specificity 78.0%),positive likelihood ratio was 3.891.Of all series tests,the Youden's index of lower extremity compressive ultrasonography+echocardiography was highest, 0.614(sensitivity 73.4%,specificity 88.0%),positive likelihood ratio was 6.120.(8)The negative likelihood ratio of several parallel tests＜0.1,having excluded value for PTE.(9)The positive likelihood ratio of all the series tests＜10,not having confirmed value for PTE.Conclusion:Geneva score was more objective and accurate,high pre-test probability of Geneva score had confirmed value for PTE;Excluding acute PTE couldn't base on negative result of D-Dimer singly whatever using semiquantitative Latex or quantitative Latex to test,we recommended using parallel tests;The sensitivity of combining clinical manifestation with results of D-Dimer and ultrasonography for suspected PTE more than 90%,even 100%;In hospitals without ECT or spiral CT,Geneva score and lower extremity compressive ultrasonography were recommended as important tests for suspected PTE.