Diagnosis of acute pulmonary embolism

Advances in the management of patients with suspected pulmonary embolism (PE) have improved diagnostic accuracy and made management algorithms safer, easier to use, and well standardized. These diagnostic algorithms are mainly based on the assessment of clinical pretest probability, D‐dimer measurement, and imaging tests—predominantly computed tomography pulmonary angiography. These diagnostic algorithms allow safe and cost‐effective diagnosis for most patients with suspected PE. In this review, we summarize signs and symptoms of PE, current existing evidence for PE diagnosis, and focus on the challenge of diagnosing PE in special patient populations, such as pregnant women, or patients with a prior VTE. We also discuss novel imaging tests for PE diagnosis and highlight some of the additional challenges that might require adjustments to current diagnostic strategies, such as the reduced clinical suspicion threshold, resulting in a lower proportion of PE among suspected patients as well as the overdiagnosis of subsegmental PE.     

急性肺血栓栓塞的多排螺旋CT诊断

目的探讨多排螺旋CT对急性肺血栓栓塞(PE)的诊断价值.方法对临床怀疑急性PE的21例患者采用多排螺旋CT行薄层肺动脉造影(CTPA)及间接法深静脉造影(CTV).结果 CTPA检出12例急性PE,间接法CTV检出深静脉血栓8例.1 mm有效层厚图像对段、亚段肺动脉及其内血栓的显示高于3 mm有效层厚图像(P<0.05).结论多排螺旋CT能促进急性PE的诊断.     

Short-term prognosis of pulmonary embolism

Summary.  Risk stratification tools that accurately quantify the prognosis of patients with pulmonary embolism (PE) may be useful in guiding medical decision making. Prospective studies demonstrated that clinical factors, echocardiographic right ventricular dysfunction, and cardiac biomarkers (troponins, brain natriuretic peptides) are independent predictors of short-term mortality in patients with PE. The presence of systemic hypotension or shock carries the highest risk of death, and thrombolysis is usually indicated. Among hemodynamically stable patients, clinical prognostic models, echocardiography, and biomarkers accurately identify low-risk patients with PE who are potential candidates for less costly outpatient care. However, the practical use of these prognostic measures is currently limited by the lack of studies demonstrating a positive impact on patient care. The benefit of risk stratification strategies based on clinical prognostic models, echocardiography, and cardiac biomarkers should be demonstrated in prospective studies before their implementation as decision aid to guide initial treatment can be recommended.     

肺栓塞的诊断方法

肺栓塞在临床上较为常见,但诊断较困难。诊断应始于识别肺栓塞发生的危险因素及评估患者发生肺栓塞的可能性大小以及患者的临床症状和体征。常规的客观检查包括D-二聚体测定、心电图、胸片及超声心动图等。近年来,尚有人研究经食道超声在肺栓塞诊断中的价值。而且,随着影像学技术的发展,CT血管造影(CTA)、磁共振血管造影(MRA)及与其相关的一系列先进手段也逐渐应用于肺栓塞的诊断中,并显示出良好的应用前景。肺血管造影一直被认为是肺栓塞诊断的金标准,有人认为,多探测器螺旋CT(MDCT)的运用可能成为诊断肺栓塞的无创金标准,但结合临床的综合判断仍是诊断的基础。     

Diagnosis of pulmonary embolism

Although pulmonary embolism (PE) is often considered a difficult diagnosis to establish, important clinical clues and properly ordered laboratory and imaging tests can reliably detect or exclude this potentially fatal condition. This article will provide a practical approach to recognizing clinical situations in which PE should be suspected. This guide to PE diagnosis will be tailored to those with busy practices, outlining a focused history and physical examination as well as optimal strategies for test ordering. Instead of performing an encyclopedic laundry list of tests, clinicians can pick and choose carefully among them, which maximizes efficiency and cost-effectiveness. The choice of tests is flexible, thus allowing the clinician to utilize the strengths of the particular hospital in which the patient is evaluated. This article will help ensure that patients with PE are identified rapidly and, conversely, that those without PE will undergo an appropriate workup for other important medical conditions. With a 3-stage approach consisting of (1) clinical evaluation; (2) nonimaging laboratory tests; and (3) imaging tests, PE can often be quickly detected with a definitive evaluation.     

血浆B型尿钠肽对急性肺栓塞患者的预后价值探讨

目的:探讨B型尿钠肽(B-type natriuretic peptide,BNP)对急性肺栓塞患者的预后价值。方法:以本院98例急性肺栓塞患者为研究对象,定量检测血浆BNP水平,随访至出院后6个月,分析BNP水平变化与急性肺栓塞患者危险分层和预后的关系,患者所有临床数据资料均应用SPSS19.0软件进行统计学分析处理。结果:与BNP水平正常的患者相比,BNP升高的患者发生休克、低氧血症等不良临床事件及死亡的比例明显升高。ROC曲线分析表明:血浆BNP水平<226.5ng/L的急性肺栓塞患者的生存率明显高于血浆BNP水平>226.5ng/L的患者(P=0.000)。结论:检测急性肺栓塞患者血浆BNP能在患者入院早期阶段较准确地预测患者的不良预后,有利于患者的危险分层以及指导进一步的治疗决策。     

急性肺栓塞诊断及预后生物标记物的研究进展

急性肺栓塞(APE)是临床上一种相对比较常见、潜在威胁生命的血管疾病,漏诊、误诊情况严重。近年来研究表明,D-二聚体、脑利钠尿肽、心肌型脂肪酸结合蛋白等生物标记物在APE的诊断及预后上有很大的临床应用价值。本文就相关生物标记物在APE的诊断和预后方面的研究进展作一综述。     

Diagnosis and management of subsegmental pulmonary embolism

Summary. Introduction: Although the advent of multi‐detector row computed tomography (CT) has enabled better visualization of subsegmental pulmonary (SSP) arteries, SSP embolism is of uncertain clinical significance. We aimed at answering the following questions: Is spiral CT an accurate method to detect SSP embolism? How are subsegmental perfusion defects managed in outcome studies including spiral CT? What are the main characteristics and outcomes of patients in whom CT detects isolated subsegmental defects? Methods: We performed a Medline search on July 1, 2004, using the keywords ‘pulmonary embolism’ and ‘computed tomography’. We limited our search to English language prospective studies comparing CT to pulmonary angiography, and to prospective outcome studies including CT in a diagnostic strategy, with at least a 3‐month follow‐up. Results: Fourteen studies comparing CT to pulmonary angiography, and five prospective management studies using CT were retrieved. The sensitivity of single‐detector CT for detecting subsegmental defects compared with pulmonary angiography was low (25%). The proportion of isolated SSP images was significantly higher in management studies using multi‐detector CT (17 of 770 scans, 2.2%) compared with those using single‐detector CT (22 of 2232, 1.0%; P = 0.01). No straightforward attitude regarding anticoagulation therapy for isolated subsegmental defects emerged from the available literature. Finally, important clinical differences were found between patients having subsegmental and segmental or more proximal defects. Conclusions: These findings underline the uncertainty regarding the clinical significance of SSP embolism, and the management of patients with such findings.     

DVT and pulmonary embolism: Part I. Diagnosis

The incidence of venous thromboembolic diseases is increasing as the U.S. population ages. At least one established risk factor is present in approximately 75 percent of patients who develop these diseases. Hospitalized patients and nursing home residents account for one half of all cases of deep venous thrombosis. A well-validated clinical prediction rule can be used for risk stratification of patients with suspected deep venous thrombosis. Used in combination with D-dimer or Doppler ultrasound tests, the prediction rule can reduce the need for contrast venography, as well as the likelihood of false-positive or false-negative test results. The inclusion of helical computed tomographic venography (i.e., a below-the-pelvis component) in pulmonary embolism protocols remains under evaluation. Specific combinations of a clinical prediction rule, ventilation-perfusion scanning, and D-dimer testing can rule out pulmonary embolism without an invasive or expensive investigation. A clinical prediction rule for pulmonary embolism is most helpful when it is used with subsequent evaluations such as ventilation-perfusion scanning, D-dimer testing, or computed tomography. Technologic advances are improving the resolution of helical computed tomography to allow detection of smaller emboli; however, further study is needed to provide definitive evidence supporting the role of this imaging technique in the diagnosis of pulmonary embolism. D-dimer testing is helpful clinically only when the result is negative. A negative D-dimer test can be used in combination with a clinical decision rule, ventilation-perfusion scanning, and/or helical computed tomography to lower the probability of pulmonary embolism to the point that aggressive treatment is not required. Evidence-based algorithms help guide the diagnosis of deep venous thrombosis and pulmonary embolism.     

急性肺栓塞的护理

肺栓塞是指嵌塞物质进入肺动脉及其分支，阻断组织血液供应所引起的病理和临床状态。既往无心肺疾病的患者，呼吸困难是肺栓塞最常见的症状（发生率80％左右），呼吸急促，呼吸频率〉20／min是最常见的体征，尤以活动时最明显。通常，呼吸困难、晕厥或发绀预示有致命性危险。肺栓塞后可导致肺梗死、急性肺原性心脏病。发病率高，     

The incidence and prognostic significance of elevated cardiac troponins in patients with submassive pulmonary embolism

Although the incidence and prognostic significance of elevated cardiac troponins are known in patients with massive pulmonary embolism (PE), few studies have addressed this issue in patients with hemodynamically stable, submassive PE, who comprise the majority of patients presenting with PE. This prospective cohort study was, therefore, designed to determine the incidence and prognostic significance of elevated cardiac troponins in patients with submassive PE. Consecutive patients with acute, symptomatic, submassive PE that was confirmed by objective diagnostic testing were studied. All patients received treatment with either unfractionated heparin or fondaparinux followed by a coumarin derivative and underwent clinical follow-up for 3 months. Cardiac troponin I (cTnI) levels were measured within 24 h of clinical presentation. An elevated cTnI was defined as > 0.5 microg L(-1) and indicated myocardial injury. Major myocardial injury, that is associated with myocardial infarction, was defined by a cTnI > 2.3 microg L(-1). The clinical outcomes were recurrent venous thromboembolism and all-cause death. In 458 patients with submassive PE, the incidence of cTnI > 0.5 microg L(-1) was 13.5%[95% confidence interval (CI): 10.4-16.7], and the incidence of cTnI > 2.3 microg L(-1) was 3.5% (95% CI: 2.0-5.6). An elevated cTnI > 0.5 microg L(-1) was associated with an increased risk of all-cause death [odds ratio (OR) = 3.5; 95% CI: 1.0-11.9], but did not appear to confer an increased risk of recurrent venous thromboembolism (OR = 1.1; 95% CI: 0.2-4.9). In patients who present with submassive PE, an elevated cTnI occurs in about one in seven patients and is associated with a 3.5-fold increased risk of all-cause death.     

心肌型脂肪酸结合蛋白在急性肺栓塞预后中的作用

目的 探讨心肌型脂肪酸结合蛋白(H-FABP)在急性肺栓塞(APE)预后中的作用.方法 检测72例确诊为急性肺栓塞(APE)患者及对照组30例健康受试者血浆H-FABP、心肌肌钙蛋白I(cTnI)、D-二聚体水平.应用Logistic回归模型分析各生化标志物与APE预后的关系.结果 APE组血浆D-二聚体水平较对照组明显增高(P<0.01).APE组中H-FABP阳性组30 d内不良事件发生率高于H-FABP阴性组(66.7% vs 3.5%,P<0.05).Logistic回归分析显示,H-FABP为APE预后的独立危险因素,H-FABP阳性者发生不良事件的危险性是H-FABP阴性者的50.44倍(95%CI 7.40～342.38,P<0.001).结论 H-FABP阳性APE者预后较差,H-FABP可用于APE的危险分层.     

急性肺栓塞病人的监护

肺动脉栓塞是内源性或外源性栓子堵塞肺动脉或其分支引起肺循环障碍的临床病理生理综合征 ,发生肺出血或坏死者称肺梗死。国外尸检发现 ,肺栓塞的临床误诊率为 67% ,假阳性率 63 % ,诊断正确者仅 2 9% [1] 。究其原因 ,可能与对肺栓塞的认识不够以及缺少有效的诊断技术和手段有关 ,后者对基层医院影响尤其大。据统计 ,经治疗的急性肺栓塞病人比不治疗者病死率低 ,治疗的病人中 92 %可生存。栓塞后由于栓子向远端移动和自身的溶解 ,只要能渡过危急期 ,预后多良好 ,这说明早期诊断、及时抗凝、溶栓治疗、严密监护是降低病死率的关键。现将 12…     

A novel ECG parameter for diagnosis of acute pulmonary embolism: RS time: RS time in acute pulmonary embolism

ObjectivesPulmonary embolism (PE) is one of the leading causes of cardiovascular mortality worldwide. Electrocardiography (ECG) may provide useful information for patients with acute PE. In this study, we aimed to investigate the diagnostic value of the QRS duration and RS time in inferolateral leads in patients admitted to the emergency department, and pre-diagnosed with acute PE.MethodsWe retrospectively enrolled 136 consecutive patients, admitted to the emergency department, pre-diagnosed with the clinical suspicion of acute PE, and underwent computerized tomographic pulmonary angiography (CTPA) to confirm the PE diagnosis. The study subjects were divided into two groups according to the presence or absence of PE, and the independent predictors of PE were investigated.ResultsSixty-eight patients (50%) had PE. Patients with PE had a longer RS time. Among the ECG parameters, only RS time was an independent predictor of PE (OR: 1.397, 95% CI: 1.171–1.667; p < 0.001). The ROC curve analyses revealed that the cut-off value of RS time for predicting acute PE was 64.20 ms with a sensitivity of 85.3% and a specificity of 79.4% (AUC: 0.846, 95%CI: 0.749–0.944; p < 0.001). In the correlation analyses; the RS time was correlated with RV end-diastolic diameter (r = 0.422; p < 0.001), RV/left ventricle (LV) ratio (r = 0.622; p < 0.001), and systolic pulmonary artery pressure (SPAP) (r = 0.508; p < 0.001).ConclusionAs a novel ECG parameter, RS time could be measured for each patient. A longer RS time can be a very useful index for diagnosing acute PE as well as for estimating the RV end-diastolic diameter and SPAP.     

B型尿钠肽在急性肺栓塞早期病情评估的意义

目的 探讨BNP(B型尿钠肽)在急性肺栓塞早期病情评估中的意义.方法 选择2005年11月至2010年6月北京友谊医院资料完全的急性肺栓塞病例86例进行回顾性分析,根据有无右心功能障碍分为两组,比较两组间BNP等相关指标间的差异,并行BNP与RV-RA PG(右心房和右心室的压力梯度值)之间的相关性分析;根据有无并发症分为两组,比较两组间BNP等相关指标间的差异.结果 (1)右心功能障碍与右心功能正常的患者,组间比较采用两组间配对t检验,两组BNP分别为(320.4±190.5) pg/ml vs. (51.5±30.79)pg/ml,P＜0.05,差异具有统计学意义.(2) BNP与右心功能RV-RA PG行线性相关分析,两组间有较好的相关性(r=0.824,P＜0.01); (3) BNP预测右心功能障碍ROC曲线分析,ROC曲线下面积(AUC值)0.907,表明BNP能较好预测右心功能障碍情况;(4)有并发症的患者与无并发症的患者,组间比较采用两组间配对t检验,两组间BNP分别为(1356.8±675.4) pg/ml vs.(103.8±51.4) pg/ml,P＜0.05,差异具有统计学意义;两组间pH分别(7.372±3.7)vs.(7.446±3.5),P＜0.05,差异具有统计学意义.结论 (1) BNP在急性肺栓塞患者的早期诊疗中,对预测患者右心衰的发生及病情的严重程度和预后有着积极的临床意义(2)早期的动脉血气pH值在急性肺栓塞患者的早期诊疗中,对预测病情的严重程度和预后有着积极的参考价值.     

Diagnosis of deep vein thrombosis and pulmonary embolism

Traditional approaches to diagnosis of deep vein thrombosis and pulmonary embolism are primarily based on the results of compression ultrasonography and the ventilation/perfusion lung scan (V/Q). Spiral computed tomographic imaging may replace the V/Q scan, and the D-Dimer assay may guide evaluation.     

Massive pulmonary embolism: review of management strategies with a focus on catheter-based techniques

Massive or high-risk pulmonary embolism (PE), defined as PE in the setting of (transient) arterial hypotension or frank cardiogenic shock, is associated with a poor prognosis. Fibrinolytic therapy is the mainstay of therapy, although data to support its effectiveness are limited. Although rarely performed, an alternate, accepted treatment strategy is surgical embolectomy. Contraindications to fibrinolytics are common in the setting of high-risk PE, and surgical embolectomy is frequently not performed owing to excessively high surgical risk. Under those circumstances, percutaneous, catheter-based thrombectomy or thrombus fragmentation is a reasonable alternative. In this article, we summarize the data available to date, evaluating the three different treatment options. We also attempt to synthesize a treatment algorithm to guide the practitioner in the treatment of patients with high-risk or massive PE.