D-dimer and exhaled CO2/O2 to detect segmental pulmonary embolism in moderate-risk patients.
D-dimer and exhaled CO2/O2 to detect segmental pulmonary embolism in moderate-risk patients.
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DOI：
10.1164/rccm.201001-0129oc
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发表时间：
2010-09
影响因子：
24.7
通讯作者：
J. Kline;M. Hogg;D. Courtney;Chadwick D Miller;A. E. Jones;H. Smithline;N. Klekowski;R. Lanier
中科院分区：
文献类型：
--
作者：
J. Kline;M. Hogg;D. Courtney;Chadwick D Miller;A. E. Jones;H. Smithline;N. Klekowski;R. Lanier
肺栓塞（PE）降低呼出气末二氧化碳与氧气的比值（etCO（2）/O（2））。目的：在D-二聚体阳性的中危人群中，检测etCO（2）/O（2）是否能在计算机断层扫描多排肺动脉造影（MDCTPA）上对节段性或较大PE的概率产生临床重要变化。方法急诊科和住院患者有一个或多个预定义的症状或体征，一个或多个危险因素的PE，和64层MDCTPA从四家医院招募。D-二聚体大于499 ng/ml为试验（+），D-二聚体小于500 ng/ml为试验（-）。7次或7次以上呼吸的etCO（2）/O（2）中位数小于0.28为测试（+），etCO（2）/O（2）大于0.45为测试（-）。MDCTPA图像由两名独立的放射科医生阅读，标准是由任何一位读片者对急性PE的解释。然后对PE尺寸进行分级。测量和主要结果我们纳入了495例患者，包括60例（12%）节段或更大的PE，29例（6%）亚节段PE。共有367例（74%）患者为D-二聚体（+），包括所有60例节段性或较大PE（后验概率16%）。D-二聚体（+）和etCO（2）/O（2）（+）的组合将节段性或更大PE的后验概率增加至28%（差异为12%的95%置信区间[CI]，3.0-22%）。在40例患者（8%; 95% CI，6-11%）中观察到D-二聚体（+）和etCO（2）/O（2）（-）的组合，无（0/40; 95% CI，0-9%）MDCTPA显示节段性或较大PE。没有策略改变亚段PE的患病率。结论：在D-二聚体阳性的中危患者中，et etCO（2）/O（2）小于0.28显著增加了节段性或更大范围PE的可能性，et etCO（2）/O（2）大于0.45预测MDCTPA上不存在节段性或更大范围PE。
RATIONALE Pulmonary embolism (PE) decreases the exhaled end-tidal ratio of carbon dioxide to oxygen (etCO(2)/O(2)). OBJECTIVES To test if the etCO(2)/O(2) can produce clinically important changes in the probability of segmental or larger PE on computerized tomography multidetector-row pulmonary angiography (MDCTPA) in a moderate-risk population with a positive D-dimer. METHODS Emergency department and hospitalized patients with one or more predefined symptoms or signs, one or more risk factors for PE, and 64-slice MDCTPA enrolled from four hospitals. D-dimer greater than 499 ng/ml was test(+), and D-dimer less than 500 ng/ml was test(-). The median etCO(2)/O(2) less than 0.28 from seven or more breaths was test(+) and etCO(2)/O(2) greater than 0.45 was test(-). MDCTPA images were read by two independent radiologists and the criterion standard was the interpretation of acute PE by either reader. PE size was then graded. MEASUREMENTS AND MAIN RESULTS We enrolled 495 patients, including 60 (12%) with segmental or larger, and 29 (6%) with subsegmental PE. A total of 367 (74%) patients were D-dimer(+), including all 60 with segmental or larger PE (posterior probability 16%). The combination of D-dimer(+) and etCO(2)/O(2)(+) increased the posterior probability of segmental or larger PE to 28% (95% confidence interval [CI] for difference of 12%, 3.0-22%). The combination of D-dimer(+) and etCO(2)/O(2)(-) was observed in 40 patients (8%; 95% CI, 6-11%), and none (0/40; 95% CI, 0-9%) had segmental or larger PE on MDCTPA. No strategy changed the prevalence of subsegmental PE. CONCLUSIONS In moderate-risk patients with a positive D-dimer, the et etCO(2)/O(2) less than 0.28 significantly increases the probability of segmental or larger PE and the etCO(2)/O(2) greater than 0.45 predicts the absence of segmental or larger PE on MDCTPA.