CT肺动脉成像结合D-二聚体对急诊肺栓塞病人的诊断价值

Clinical value of combined CT pulmonary angiography and D-dimer in patients with acute pulmonary embolism in emergency department

目的分析以胸痛为主要表现于急诊就诊的病人采用CT肺动脉成像(CTPA)结合D-二聚体检测肺栓塞的临床应用价值。方法回顾性分析自2015年1月1日—2017年6月30日于急诊以胸痛就诊并行CTPA检查的病人155例,其中男83例,女72例,年龄13~84岁,平均(55±16)岁。分析和记录肺栓塞的有无及其发生率,分析无肺栓塞病人伴发的有临床诊疗意义的病变。记录纳入病人的D-二聚体值。采用Fisher精确检验分析D-二聚体阳性组和阴性组CTPA上肺栓塞的检出率;采用独立样本t检验比较D-二聚体异常组CTPA上肺栓塞病人和非肺栓塞病人的D-二聚体值。以CTPA诊断为参考标准,评估D-二聚体在诊断肺栓塞中的价值。结果155例病人中,50例(32.3%)病人经CTPA诊断为肺栓塞,105例(67.7%)病人无肺栓塞。152例病人进行了D-二聚体测量。按照常规D-二聚体参考值0.5 mg/d L为阳性阈值,其中二聚体值阳性128例,阴性24例。24例D-二聚体值阴性者CTPA上均无肺栓塞(0/24),CTPA上有肺栓塞的50例病人(50/128,39.1%)的D-二聚体值为阳性,78例D-二聚体阳性者的CTPA上无肺栓塞,2组肺栓塞检出率的差异有统计学意义(Fisher精确检验,P<0.001)。D-二聚体值阳性组中,50例病人于CTPA上诊断为肺栓塞,78例CTPA上无肺栓塞,两者的平均D-二聚体值差异无统计学意义[分别为(6.11±5.59)mg/d L和(5.26±6.67)mg/d L,t=0.741,P=0.460]。以CTPA检测结果为参考,D-二聚体诊断肺栓塞的敏感度、特异度、阳性预测值、阴性预测值分别为100%、23.5%、39.1%、100%。结论本研究提示结合D-二聚体的测定推荐CTPA检查有助于进一步提高肺栓塞检测的阳性率。

Objective To analyze the clinical value of combined CT pulmonary angiography（CTPA） and D-dimer in detecting pulmonary embolism patients with acute chest pain. Methods There were 155 patients（83 males and 72 females,age from 13-84 years, mean age of 55±16 years） with chest pain who underwent CTPA during Jan. 1 st, 2015 to June 30, 2017 in our Department of Emergency were retrospectively studied. The presence and incidence of pulmonary embolism, clinically implicated concurrent lesions in patients without pulmonary embolism, and D-dimer value were recorded and analysed.Incidences of pulmonary embolism in positive and negative D-dimer groups were compared with Fisher＇s exact test. D-dimer values between pulmonary embolism patients and non-pulmonary embolism patients in abnormal D-dimer patients were compared with independent sample t test. With CTPA findings as reference standard, the diagnostic performance of D-dimer was calculated for diagnosing pulmonary embolism. Results Of 155 patients, 50 patients were diagnosed as having pulmonary embolism（32.3%）, while 105 patients（67.7%） had no pulmonary embolism. There were 152 patients had D-dimer measurement. With 0.5 mg/d L as cut-off value, 128 patients had elevated D-dimer and 24 patients had normal D-dimer value. No pulmonary embolism was detected in CTPA in all 24 patients with normal D-dimer value（0/24）, while 50 patients with pulmonary embolism（50/128, 39.1%） and 78 patients without pulmonary embolism in CTPA had elevated D-dimer val-ue. Statistical difference was found between the incidences of pulmonary embolism in the positive and negative D-dimer groups（Fisher＇s exact test, P〈0.001）. In abnormal D-dimer group, 50 patients had pulmonary embolism in CTPA while 78 patients had no pulmonary embolism in CTPA, no significant difference was found for their mean D-dimer values（6.11 ±5.59 mg/d L vs 5.26±6.67 mg/d L; t=0.741, P=0.460）. With CTPA findings as reference standard, the sensitivity, specificity, negative predictive value, and positive predictive value of D-dimer for diagnosing pulmonary embolism were 100%, 23.5%,39.1%, and 100%, respectively. Conclusions Combining the D-dimer measurements can improve the positive findings of pulmonary embolism in CTPA.