Application Value of Ultrasonic Blood Flow Parameters,D-dimer Detection and Composite Model in Early Warning of Lower Limb DVT in Orthopedic Trauma Patients

WANG Lei; LU Xinming

doi:10.3969/j.issn.1002-3429.2024.05.011

Abstract：Objective To explore the changes of ultrasonic blood flow parameters[peak systolic blood velocity(Vs),end-diastolic blood velocity(Vd),resistance index(RI)],and D-dimer(D-D)before and after surgery and the ap-plication value of composite model in early warning of deep vein thrombosis(DVT)in orthopedic trauma patients.Methods A total of 200 orthopedic trauma patients treated from July 2021 to July 2023 were selected and divided into occurrence group(n=25)and non-occurrence group(n=175).Baseline data and Vs,Vd,RI,and D-D before and after surgery were col-lected from the two groups of patients.A predictive composite model was constructed according to the influencing factors of oc-currence of lower-limb DVT in orthopedic trauma patients after surgery,and the predictive value of combination of difference in Vs,Vd,RI,D-D before and after surgery and composite model for occurrence of lower-limb DVT in orthopedic trauma pa-tients after surgery was evaluated.Decision curve analysis(DCA)was drawn to analyze the benefit of ultrasonic blood flow pa-rameters,D-D detection and composite model in predicting the occurrence of lower-limb DVT in patients with orthopedic trau-ma after surgery.Results The duration of surgery and the proportion of tourniquet use in the occurrence group were longer or higher than those in the non-occurrence group(P＜0.01).At 3 days after surgery,Vs and Vd in the occurrence group were lower than those in the non-occurrence group,and RI and D-D were higher than those in the non-occurrence group(P＜0.01).The difference in Vs,Vd,RI and D-D before and after surgery in the occurrence group was greater than that in the non-occurrence group(P＜0.01).Multivariate Logistic regression analysis showed that duration of surgery,intraoperative tourniquet use and the difference in Vs,Vd,RI and D-D before and after surgery were independent risk factors for lower-limb DVT in orthopedic trauma patients(P＜0.01).The difference in Vs,Vd,RI and D-D before and after surgery was used as the predictive indexes to draw the receiver operating characteristic(ROC)curve,and the area under the curve(AUC)of Vs,Vd,RI and D-D in combination in predicting the occurrence of lower-limb DVT was0.882(95%CI:0.829,0.923),and the sensitivity and specificity were both 0.88.The lower-limb DVT prediction model was constructed,and its AUC value was 0.920(95%CI:0.873,0.954).The detrended correspondence analysis(DCA)showed that the composite model had high-er clinical value when the threshold probability was 0.10-0.90.Conclusion The duration of surgery,the intraoperative use of tourniquet and the difference in Vs,Vd,RI and D-D before and after surgery are independent risk factors for DVT in ortho-pedic trauma patients.Compared with the difference in Vs,Vd,RI and D-D before and after surgery,the composite model es-tablished by combining multiple indexes has higher application value in the early warning of lower-limb DVT after surgery for orthopedic trauma.