Objective: To investigate the predictive value of D-dimer for deep venous thrombosis (DVT) of lower extremity in adult burn patients. Methods: A retrospective case series study was conducted. The clinical data of 3 861 adult burn patients who met the inclusion criteria and were admitted to the Department of Burns of Zhengzhou First People's Hospital from January 1, 2015 to December 31, 2019 were collected. The patients were divided into DVT group (n=77) and non-DVT group (n=3 784) according to whether DVT of lower extremity occurred during hospitalization or not. Data of patients in the two groups were collected and compared, including the gender, age, total burn area, D-dimer level, with lower limb burn and inhalation injury or not on admission, with sepsis/septic shock, femoral vein indwelling central venous catheter (CVC), history of surgery, and infusion of concentrated red blood cells or not during hospitalization. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test. The indicators with statistically significant differences between the two groups were analyzed with multivariate logistic regression analysis to screen the independent risk factors for DVT of lower extremity in 3 861 adult burn patients. The receiver operating characteristic (ROC) curve of the independent risk factors predicting DVT of lower extremity in 3 861 adult burn patients were drawn, and the area under the curve (AUC), the optimal threshold value, and the sensitivity and specificity under the optimal threshold value were calculated. The quality of the AUC was compared by Delong test, and the sensitivity and specificity under the optimal threshold value were compared using chi-square test. Results: There were no statistically significant differences in gender, occurrence of sepsis/septic shock or history of surgery during hospitalization between patients in the two groups (P>0.05), while there were statistically significant differences in age, total burn area, D-dimer level, lower limb burn and inhalation injury on admission, and femoral vein indwelling CVC and infusion of concentrated red blood cells during hospitalization between patients in the two groups (t=-8.17, with Z values of -5.04 and -10.83, respectively, χ2 values of 21.83, 5.37, 7.75, and 4.52, respectively, P<0.05 or P<0.01). Multivariate logistic regression analysis showed that age, total burn area, and D-dimer level were the independent risk factors for DVT of lower extremity in 3 861 adult burn patients (with odds ratios of 1.05, 1.02, and 1.14, respectively, 95% confidence intervals of 1.04-1.06, 1.00-1.03, and 1.10-1.20, respectively, P<0.05 or P<0.01). The AUCs of ROC of age, total burn area, and D-dimer level for predicting DVT of lower extremity in 3 861 adult burn patients were 0.74, 0.67, and 0.86, respectively (with 95% confidence intervals of 0.68-0.80, 0.60-0.74, and 0.83-0.89, respectively, P values<0.01), the optimal threshold values were 50.5 years old, 10.5% total body surface area, and 1.845 mg/L, respectively, the sensitivity under the optimal threshold values were 71.4%, 70.1%, and 87.0%, respectively, and the specificity under the optimal threshold values were 66.8%, 67.2%, and 72.9%, respectively. The AUC quality and sensitivity and specificity under the optimal threshold value of D-dimer level were significantly better than those of age (z=3.29, with χ2 values of 284.91 and 34.25, respectively, P<0.01) and total burn area (z=4.98, with χ2 values of 326.79 and 29.88, respectively, P<0.01), while the AUC quality and sensitivity and specificity under the optimal threshold values were similar between age and total burn area (P>0.05). Conclusions: D-dimer level is an independent risk factor for DVT of lower extremity in adult burn patients, its AUC quality and sensitivity and specificity under the optimal threshold value are better than those of age and total burn area, and it has good predictive value for DVT of lower extremity in adult burn patients.
目的： 探讨D-二聚体对成年烧伤患者并发下肢深静脉血栓形成（DVT）的预测价值。 方法： 采用回顾性病例系列研究方法。收集2015年1月1日—2019年12月31日郑州市第一人民医院烧伤科收治的符合入选标准的3 861例成年烧伤患者的临床资料。按住院期间是否并发下肢DVT，将患者分为DVT组（77例）和非DVT组（3 784例），收集并比较2组患者的性别、年龄、烧伤总面积、D-二聚体水平，入院时有无下肢烧伤、吸入性损伤，住院期间是否并发脓毒症/感染性休克及有无股静脉留置中心静脉导管（CVC）、外科手术史、输注浓缩红细胞。对数据行独立样本t检验、Mann-Whitney U检验、χ2检验。选取组间比较差异具有统计学意义的指标进行多因素logistic回归分析，筛选3 861例成年烧伤患者并发下肢DVT的独立危险因素。绘制独立危险因素预测3 861例成年烧伤患者并发下肢DVT的受试者操作特征（ROC）曲线，计算曲线下面积（AUC）、最佳阈值及最佳阈值下的敏感度、特异度。采用Delong检验对AUC的质量进行比较，采用χ2检验对最佳阈值下的敏感度和特异度进行比较。 结果： 2组患者性别及住院期间脓毒症/感染性休克发生情况、外科手术史比较，差异均无统计学意义（P>0.05）；2组患者年龄、烧伤总面积、D-二聚体水平，入院时下肢烧伤情况、吸入性损伤情况，住院期间股静脉留置CVC和输注浓缩红细胞情况比较，差异均有统计学意义（t=-8.17，Z值分别为-5.04、-10.83，χ2值分别为21.83、5.37、7.75、4.52，P<0.05或P<0.01）。多因素logistic回归分析显示，年龄、烧伤总面积和D-二聚体水平均是3 861例成年烧伤患者并发下肢DVT的独立危险因素（比值比分别为1.05、1.02、1.14，95%置信区间分别为1.04~1.06、1.00~1.03、1.10~1.20，P<0.05或P<0.01）。年龄、烧伤总面积和D-二聚体水平预测3 861例成年烧伤患者并发下肢DVT的ROC的AUC分别为0.74、0.67、0.86（95%置信区间分别为0.68~0.80、0.60~0.74、0.83~0.89，P值均<0.01），最佳阈值分别为50.5岁、10.5%体表总面积、1.845 mg/L，最佳阈值下的敏感度分别为71.4%、70.1%、87.0%，最佳阈值下的特异度分别为66.8%、67.2%、72.9%。D-二聚体水平的AUC质量及最佳阈值下的敏感度、特异度均优于年龄（z=3.29，χ2值分别为284.91、34.25，P<0.01）和烧伤总面积（z=4.98，χ2值分别为326.79，29.88，P<0.01），年龄、烧伤总面积间的AUC质量及最佳阈值下的敏感度、特异度均相近（P>0.05）。 结论： D-二聚体水平是成年烧伤患者并发下肢DVT的独立危险因素，其AUC质量及最佳阈值下的敏感度、特异度优于年龄和烧伤总面积，对成年烧伤患者并发下肢DVT具有较好预测价值。.