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1.
PURPOSE: To evaluate a diagnostic strategy for pulmonary embolism that combined clinical assessment, plasma D-dimer measurement, lower limb venous ultrasonography, and helical computed tomography (CT). METHODS: A cohort of 965 consecutive patients presenting to the emergency departments of three general and teaching hospitals with clinically suspected pulmonary embolism underwent sequential noninvasive testing. Clinical probability was assessed by a prediction rule combined with implicit judgment. All patients were followed for 3 months. RESULTS: A normal D-dimer level (<500 microg/L by a rapid enzyme-linked immunosorbent assay) ruled out venous thromboembolism in 280 patients (29%), and finding a deep vein thrombosis by ultrasonography established the diagnosis in 92 patients (9.5%). Helical CT was required in only 593 patients (61%) and showed pulmonary embolism in 124 patients (12.8%). Pulmonary embolism was considered ruled out in the 450 patients (46.6%) with a negative ultrasound and CT scan and a low-to-intermediate clinical probability. The 8 patients with a negative ultrasound and CT scan despite a high clinical probability proceeded to pulmonary angiography (positive: 2; negative: 6). Helical CT was inconclusive in 11 patients (pulmonary embolism: 4; no pulmonary embolism: 7). The overall prevalence of pulmonary embolism was 23%. Patients classified as not having pulmonary embolism were not anticoagulated during follow-up and had a 3-month thromboembolic risk of 1.0% (95% confidence interval: 0.5% to 2.1%). CONCLUSION: A noninvasive diagnostic strategy combining clinical assessment, D-dimer measurement, ultrasonography, and helical CT yielded a diagnosis in 99% of outpatients suspected of pulmonary embolism, and appeared to be safe, provided that CT was combined with ultrasonography to rule out the disease.  相似文献   

2.
The effectiveness of new diagnostic tools for suspected pulmonary embolism (PE), such as clinical probability assessment, plasma D-dimer (DD) measurement and lower limb venous compression ultrasonography (US), has not been specifically studied in patients with a suspected PE occurring during hospital stay. This study applied a sequential, decision analysis-based strategy adding these instruments to a ventilation/perfusion lung scan in a cohort of 114 consecutive inpatients clinically suspected of PE in order to establish in how many patients a pulmonary angiogram could thereby be avoided. A definitive diagnosis could be established by the noninvasive protocol in 61% of these patients: normal/near-normal lung scan, 14%; high probability lung scan, 19%; clinical probability combined with lung scan result, 18%; and US, 8%. Specificity of DD was only 7% and contributed to the exclusion of PE in only two patients. Pulmonary angiography was required in 39% of patients. The 3-month thromboembolic risk in patients in whom PE was excluded by the diagnostic process was 0% (95% confidence interval 0-4.9%). In conclusion, a noninvasive work-up for suspected pulmonary embolism is effective in hospitalized patients, allowing to forego angiography in 61% of them, and it appears to be safe, although this should be further investigated. In contrast to outpatients, D-dimer measurement appears to be useless in hospitalized patients.  相似文献   

3.
The measurement of D-dimer can provide useful information to aid in the diagnosis of patients with suspected venous thromboembolism. D-dimer measurement in conjunction with adequate estimation of pretest probability can facilitate the safe discharge of patients with suspected pulmonary embolism and limit unnecessary investigation or anticoagulation. We review clinical decision-making strategies in the diagnosis of pulmonary embolism and propose means to minimize diagnostic error that might arise from knowledge of the D-dimer result prior to clinical assessment.  相似文献   

4.
PURPOSE: The diagnosis of pulmonary embolism in the elderly is often difficult because of comorbid medical conditions, and perhaps also because diagnostic tests have a lower yield. We analyzed the diagnostic performance of common diagnostic tests for pulmonary embolism in different age groups. METHODS: We analyzed data from two large studies that enrolled 1,029 consecutive patients presenting to the emergency department with clinically suspected pulmonary embolism. The clinical probability of pulmonary embolism (high [>/=80%], intermediate, or low [/=80 years of age. The positive predictive value of a high clinical probability of pulmonary embolism was greater in the elderly (71% to 78% in those >/=60 years old versus 40% to 64% in those /=80 years old. The diagnostic yield of lower limb compression ultrasonography was greater in the elderly. The proportion of lung scans that were diagnostic (normal, near-normal, or high probability) decreased from 68% to 42% with increasing age. CONCLUSIONS: Age affects the performance of common diagnostic tests for pulmonary embolism and should be kept in mind when evaluating patients suspected of having this condition.  相似文献   

5.
PURPOSE OF REVIEW: To discuss reports published in 2005 on the diagnosis of clinically suspected nonmassive pulmonary embolism. RECENT FINDINGS: Progress has been made in assessing the clinical probability of pulmonary embolism, in addressing diagnosis in the elderly, in evaluating the diagnostic performance of single-detector and multidetector row helical computed tomography, and in the role of D-dimer measurement and lower limb venous compression ultrasonography in the diagnostic work-up of pulmonary embolism. SUMMARY: Diagnosing venous thromboembolism depends mainly on noninvasive diagnostic tools that are used sequentially. In most patients, a noninvasive work-up is feasible and the diagnostic algorithms are becoming simpler. This review focuses on developments in clinical probability assessment, pulmonary embolism in the elderly, potential new uses of D-dimer measurement, advent of multidetector row helical computed tomography, and utility of ultrasonography in detecting deep vein thrombosis in patients with suspected pulmonary embolism. With the development of potentially more sensitive diagnostic tests for pulmonary embolism, physicians are now facing the risk of overdiagnosis and hence overtreatment. The issue will no longer be just to detect clots but to identify patients who must be treated using anticoagulants, a complicated question.  相似文献   

6.

Purpose

To formulate comprehensive recommendations for the diagnostic approach to patients with suspected pulmonary embolism, based on randomized trials.

Methods

Diagnostic management recommendations were formulated based on results of the Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II) and outcome studies.

Results

The PIOPED II investigators recommend stratification of all patients with suspected pulmonary embolism according to an objective clinical probability assessment. D-dimer should be measured by the quantitative rapid enzyme-linked immunosorbent assay (ELISA), and the combination of a negative D-dimer with a low or moderate clinical probability can safely exclude pulmonary embolism in many patients. If pulmonary embolism is not excluded, contrast-enhanced computed tomographic pulmonary angiography (CT angiography) in combination with venous phase imaging (CT venography), is recommended by most PIOPED II investigators, although CT angiography plus clinical assessment is an option. In pregnant women, ventilation/perfusion scans are recommended by many as the first imaging test following D-dimer and perhaps venous ultrasound. In patients with discordant findings of clinical assessment and CT angiograms or CT angiogram/CT venogram, further evaluation may be necessary.

Conclusion

The sequence for diagnostic test in patients with suspected pulmonary embolism depends on the clinical circumstances.  相似文献   

7.
In patients with chronic obstructive pulmonary disease (COPD), differentiating a pulmonary embolism (PE) from an exacerbation of COPD can be difficult, since clinical signs and symptoms of the two conditions overlap. Development of reliable noninvasive or minimally invasive techniques for the diagnosis of PE is, especially in these patients, necessary. In this study we assessed the effect of COPD on the accuracy of the clinical probability estimate (CPE), spiral computed tomographic angiography (SCTA), D-dimer analysis, ventilation perfusion (V/Q) scintigraphy, and pulmonary angiography for the diagnosis of PE. From May 1997 through March 1998, 627 consecutive patients with suspected PE were investigated in six teaching hospitals. In these patients, D-dimer testing, CPE, V/Q scintigraphy, and SCTA and/or pulmonary angiography were performed according to a strict diagnostic protocol. The patients were also independently categorized as having COPD or not. A diagnosis of COPD was established in 91 patients (15%). The prevalence of PE was similar in patients with and without COPD (29% and 31%, respectively), notwithstanding the larger proportion of nondiagnostic V/Q scan results in patients with COPD (46% versus 21%, p < 0.001). The distribution of CPEs, diagnostic value of the D-dimer assay and SCTA, and reproducibility of pulmonary angiography were comparable among patients with and without COPD. The presence of COPD does not affect the diagnostic performance of CPE, D-dimer testing, SCTA, or pulmonary angiography. Furthermore, although more nondiagnostic V/Q scan results can be expected in the presence of COPD, V/Q scintigraphy remains a valuable screening test in patients with COPD.  相似文献   

8.
Objective. To determine the utility of high quantitative D-dimer levels in the diagnosis of pulmonary embolism. Methods. D-dimer testing was performed in consecutive patients with suspected pulmonary embolism. We included patients with suspected pulmonary embolism with a high risk for venous thromboembolism, i.e. hospitalized patients, patients older than 80 years, with malignancy or previous surgery. Presence of pulmonary embolism was based on a diagnostic management strategy using a clinical decision rule (CDR), D-dimer testing and computed tomography. Results. A total of 1515 patients were included with an overall pulmonary embolism prevalence of 21%. The pulmonary embolism prevalence was strongly associated with the height of the D-dimer level, and increased fourfold with D-dimer levels greater than 4000 ng mL(-1) compared to levels between 500 and 1000 ng mL(-1). Patients with D-dimer levels higher than 2000 ng mL(-1) and an unlikely CDR had a pulmonary embolism prevalence of 36%. This prevalence is comparable to the pulmonary embolism likely CDR group. When D-dimer levels were above 4000 ng mL(-1), the observed pulmonary embolism prevalence was very high, independent of CDR score. Conclusion. Strongly elevated D-dimer levels substantially increase the likelihood of pulmonary embolism. Whether this should translate into more intensive diagnostic and therapeutic measures in patients with high D-dimer levels irrespective of CDR remains to be studied.  相似文献   

9.
PURPOSE OF REVIEW: This review describes the accuracy of multidetector contrast-enhanced computed tomography (CT) for the diagnosis of acute pulmonary embolism, the role of clinical assessment and of venous phase imaging in combination with it, and the approach to the diagnosis. RECENT FINDINGS: The sensitivity of CT angiography was 83%, specificity 96% and positive predictive value 86%. Positive predictive values were 97% for pulmonary embolism in a main or lobar artery, 68% for a segmental vessel, and 25% for a subsegmental branch. A CT angiogram with concordant clinical probability assessment resulted in high predictive values, but with a discordant clinical probability, predictive value was low. The sensitivity for pulmonary embolism increased to 90% by using CT venography in combination with CT angiography.A negative D-dimer by the rapid enzyme-linked immunosorbent assay method with a low or moderate probability clinical assessment can safely exclude pulmonary embolism. Clinical probability assessment and D-dimer are recommended. In general, CT angiography in combination with CT venography is recommended, but the choice of diagnostic tests depends on the clinical situation. SUMMARY: The reliability of multislice CT angiography is enhanced by clinical assessment and CT venography used with it. Clinical assessment and D-dimer are recommended before imaging.  相似文献   

10.
Pulmonary angiography is the gold standard for diagnosis of segmental pulmonary embolism, but no longer for subsegmental pulmonary embolism because the inter-observer agreement for angiographically documented subsegmental pulmonary embolism is only 60%. A normal rapid ELISA VIDAS D-dimer test result and a normal perfusion scan exclude pulmonary embolism with a negative predictive value of >99%, irrespective of clinical score. The positive predictive value for pulmonary embolism of a high probability VP-scan compared to pulmonary angiography is 87% indicating that 13% of patients with a high probability VP-scan do not have pulmonary embolism. The combination of a negative CUS, a low clinical score, and a non-diagnostic VP-scan safely excludes pulmonary embolism. Patients with a non-diagnostic VP-scan, a negative CUS, but a moderate to high clinical score are candidates for pulmonary angiography. The positive predictive value of helical spiral CT is >95 to 99%. The combination of a negative CUS, a low clinical score, and the presence of a clear alternative diagnosis is predicted to safely exclude pulmonary embolism. Helical spiral CT detects all clinical relevant pulmonary emboli and a large number of alternative diagnoses in symptomatic patients with a non-diagnostic or a high-probability VP-scan. The negative predictive value during 3 months followup after a negative spiral CT for pulmonary embolism in 4 retrospective studies and 1 prospective management study was >99%. Only a small group of patients (1-2%) with a non-diagnostic spiral CT are candidates for pulmonary angiography. Therefore, it is predicted that the spiral CT will replace both VP-scanning and pulmonary angiography to safely exclude or diagnose pulmonary emboli in patients with suspected pulmonary embolism.  相似文献   

11.
D-dimer blood tests have been suggested to rule out pulmonary embolism. Despite evidence of the safety of withholding anticoagulant treatment in patients with suspected pulmonary embolism and a normal D-dimer assay result, clinicians remain reluctant to use a D-dimer assay as a sole diagnostic test. This prospective study in 314 consecutive inpatients and outpatients investigates the relation between the diagnostic accuracy of D-dimer plasma concentration and pulmonary embolus location. Plasma D-dimer levels were measured using a quantitative immunoturbidimetric method. A strict protocol of ventilation-perfusion scintigraphy, pulmonary angiography, and spiral computed tomography was used to arrive at a final diagnosis and to assess the largest pulmonary artery in which embolus was visible. The influence of embolus location on the diagnostic accuracy was evaluated using the Kruskal-Wallis test and receiver operator characteristics (ROC) analysis. There was a strong correlation between plasma D-dimer concentration and embolus location (Kruskal-Wallis, p < 0.001). Thus, the assay showed greater accuracy in excluding segmental or larger emboli (sensitivity = 93%) than subsegmental emboli (sensitivity = 50%). D-dimer concentration and the accuracy of D-dimer assays are clearly dependent on embolus location and smaller, subsegmental emboli may be missed when D-dimer assays are used as a sole test to exclude pulmonary embolism.  相似文献   

12.
Deep vein thrombosis (DVT) and pulmonary embolism (PE) cannot be diagnosed solely on a clinical basis owing to the lack of sensitivity and specificity of clinical signs and symptoms. Phlebography and pulmonary angiography are invasive and resource-demanding imaging modalities. Because the prevalence of DVT and PE is relatively low (typically 20% or less) among clinically suspected individuals, submitting all of them to imaging would not be cost-effective. Therefore, non-invasive diagnostic algorithms have been developed that include clinical probability assessment and D-dimer measurement. These initial steps allow the selection of patients who require non-invasive imaging: compression ultrasonography in cases of suspected DVT and multidetector computed tomography (CT) angiography in cases of suspected PE. This review gives a critical appraisal of the sequential steps of the diagnostic work-up in suspected DVT or PE.  相似文献   

13.
BACKGROUND: The limitations of the current diagnostic standard, ventilation-perfusion lung scanning, complicate the management of patients with suspected pulmonary embolism. We previously demonstrated that determining the pretest probability can assist with management and that the high negative predictive value of certain D -dimer assays may simplify the diagnostic process. OBJECTIVE: To determine the safety of using a simple clinical model combined with D -dimer assay to manage patients presenting to the emergency department with suspected pulmonary embolism. DESIGN: Prospective cohort study. SETTING: Emergency departments at four tertiary care hospitals in Canada. PATIENTS: 930 consecutive patients with suspected pulmonary embolism. INTERVENTIONS: Physicians first used a clinical model to determine patients' pretest probability of pulmonary embolism and then performed a D -dimer test. Patients with low pretest probability and a negative D -dimer result had no further tests and were considered to have a diagnosis of pulmonary embolism excluded. All other patients underwent ventilation-perfusion lung scanning. If the scan was nondiagnostic, bilateral deep venous ultrasonography was done. Whether further testing (by serial ultrasonography or angiography) was done depended on the patients' pretest probability and the lung scanning results. MEASUREMENTS: Patients received a diagnosis of pulmonary embolism if they had a high-probability ventilation-perfusion scan, an abnormal result on ultrasonography or pulmonary angiography, or a venous thromboembolic event during follow-up. Patients for whom the diagnosis was considered excluded were followed up for 3 months for the development of thromboembolic events. RESULTS: The pretest probability of pulmonary embolism was low, moderate, and high in 527, 339, and 64 patients (1.3%, 16.2%, and 37.5% had pulmonary embolism), respectively. Of 849 patients in whom a diagnosis of pulmonary-embolism had initially been excluded, 5 (0.6% [95% CI, 0.2% to 1.4%]) developed pulmonary embolism or deep venous thrombosis during follow-up. However, 4 of these patients had not undergone the proper diagnostic testing protocol. In 7 of the patients who received a diagnosis of pulmonary embolism, the physician had performed more diagnostic tests than were called for by the algorithm. In 759 of the 849 patients in whom pulmonary embolism was not found on initial evaluation, the diagnostic protocol was followed correctly. Only 1 (0.1% [CI, 0.0% to 0.7%]) of these 759 patients developed thromboembolic events during follow-up. Of the 437 patients with a negative D -dimer result and low clinical probability, only 1 developed pulmonary embolism during follow-up; thus, the negative predictive value for the combined strategy of using the clinical model with D -dimer testing in these patients was 99.5% (CI, 99.1% to 100%). CONCLUSION: Managing patients for suspected pulmonary embolism on the basis of pretest probability and D -dimer result is safe and decreases the need for diagnostic imaging.  相似文献   

14.
An estimated 300,000 to 500,000 patients develop a pleural effusion secondary to pulmonary embolism each year in the United States. The pleural effusions due to pulmonary embolism are usually small. They occupy less than one third of the hemithorax in 90% and are frequently manifest only as blunting of the costophrenic angle. The pleural fluid with pulmonary embolism is almost always an exudate. When pulmonary embolism is considered a diagnostic possibility, the clinical probability of pulmonary embolism should be assessed. If the probability is low, measurement of D-dimers is useful. If the D-dimer test is negative, the diagnosis is virtually excluded. If the D-dimer test is positive or if there is a high clinical probability of pulmonary embolism, the best test to assess the possibility of pulmonary embolism is probably the computed tomographic angiogram (CTA). Patients who have a high probability of pulmonary embolism should be anticoagulated while the definitive test is being performed. The presence of a pleural effusion does not alter the standard treatment for pulmonary embolism. The two complications of pleural effusions in patients with pulmonary embolism are hemothorax and pleural infection. If the pleural effusion increases in size while a patient is being treated for pulmonary embolism, a diagnostic thoracentesis should be performed to rule out these complications.  相似文献   

15.
Nowadays the diagnosis of pulmonary embolism (PE) is based on a "diagnostic strategy" rather than a single test. The first step, after identifying patients with suspicion of PE, is to establish the pre-test clinical probability. Several scores are available to make a standardised and reproducible assessment of the clinical probability and these, therefore, represent valuable diagnostic tools. Indeed, it is the clinical probability that guides further investigation. In patients with low or intermediate clinical probability, PE can be safely ruled out by a negative D-dimer in approximately one-third of patients without additional imaging. In the case of a positive D-dimer or high clinical probability, CT pulmonary angiography is now the recommended imaging technique. However, lower limb venous compression ultrasound and ventilation/perfusion scans remain useful in patients with contraindications to CT; mainly those with renal insufficiency. In the presence of readily available and strongly validated diagnostic strategies, the challenge for the future will probably be better identification of patients in whom PE should be suspected.  相似文献   

16.
In 90% of cases the clinical suspicion of pulmonary embolism (PE) is raised by clinical signs and symptoms, while in only 10% of cases PE is suspected on the basis of electrocardiographic, arterial blood gas analysis or radiological findings. The combination of clinical signs and symptoms and the results of first-level diagnostic tests (electrocardiography, gas analysis and chest X-ray) allows a fairly accurate classification of patients with "clinical suspicion of PE" into three categories of clinical (or pre-test) probability: low, intermediate and high. The clinical diagnosis of PE is very often inaccurate making the use of additional tests, including imaging techniques, mandatory. The choice and the combination (= diagnostic algorithms) of second- and third-level diagnostic tests (D-dimer, venous ultrasound, echocardiography, lung scintigraphy, helical computed tomography and pulmonary angiography) depend primarily on the clinical conditions of patients and their pre-test probability. We propose two diagnostic algorithms: 1) a diagnostic algorithm for patients with clinically suspected PE and critical clinical conditions (unstable patients), 2) a diagnostic algorithm for patients with clinically suspected PE and non-critical clinical conditions (hemodynamically stable patients).  相似文献   

17.
D-二聚体在肺栓塞诊断中的作用研究   总被引:8,自引:0,他引:8  
目的 研究D-二聚体在诊断肺栓塞中的作用。方法 对80例临床可疑肺栓塞的患者进行回顾性分析,病人均行血D-二聚体测定和肺灌注扫描,通过肺扫描分为正常组、高可能性组和非诊断组,非诊断组再经肺动脉造影确定诊断。血D-二聚体测定采用乳胶凝集法。结果 共检出肺栓塞阳性41例,阴性39例,检出率51.2%。D-二聚体的敏感性和特异性分别为58.5%、51.3%,阳性预测值和阴性预测值分别为55.8%、54.5%。结论 D-二聚体测定尚不宜作为肺栓塞的筛选指标。  相似文献   

18.
BACKGROUND: We designed a diagnostic strategy, based on clinical probability and D-dimer concentration, to select patients who were unlikely to have pulmonary embolism (PE), before further diagnostic workup was performed. The utility and safety of this strategy were evaluated in a prospective management study. METHODS: Consecutive patients with suspected PE had D-dimer testing and clinical probability assessment with a clinical decision rule. Patients with a low probability and a normal D-dimer concentration (<500 ng/mL) were considered not to have PE, and further diagnostic testing and anticoagulant therapy were withheld. In patients with a low probability and elevated D-dimer level or with a moderate or high probability, bilateral compression ultrasonography of the legs was performed. If deep venous thrombosis was detected, venous thromboembolism was diagnosed. If compression ultrasonography was normal, pulmonary angiography was performed. All patients were followed up for 3 months. RESULTS: Of the 234 consecutive patients, 26% had the combination of a low probability and normal D-dimer level. During the follow-up period, none of these patients died and 3 patients had recurrent complaints of PE. In these 3 patients, PE was excluded by objective testing. The 3-month thromboembolic risk was therefore 0% (95% confidence interval, 0%-6%). The prevalence of PE in the entire population was 22%. CONCLUSIONS: The combination of a low clinical probability and a normal D-dimer concentration appears to be a safe method to exclude PE, with a high clinical utility, and is readily accepted by clinicians.  相似文献   

19.
Due to the morbidity and mortality associated with either untreated disease or inappropriate anticoagulant therapy, accurate diagnosis of pulmonary embolism is essential. Pulmonary angiography, the current gold standard test for diagnosing pulmonary embolus, is both invasive and costly; therefore, noninvasive diagnostic strategies have been developed. Noninvasive tests often have to be combined to either raise the posttest probability of disease to a level justifying treatment or lower it to a level at which withholding treatment is warranted. Diagnostic algorithms involving clinical assessment; venous ultrasonography; D-dimer testing; ventilation-perfusion lung scanning; and, more recently, computed tomography have been validated in management trials of patients with a suspected pulmonary embolism. The optimal strategy at individual institutions is dependent on local availability, expertise, and cost. Magnetic resonance imaging and combined computed tomographic pulmonary angiography and venography possess the potential to be used as stand-alone tests for pulmonary embolism but require further evaluation.  相似文献   

20.
目的探讨心电图与D-二聚体在急性肺栓塞患者的诊断价值。方法选择在我院接受诊治的经肺动脉血管造影检查确诊为急性肺栓塞患者58例作为研究对象,另外选取同期在我院治疗的经X线及细菌学检查确诊为慢性支气管炎患者53例作为对照组,所有患者均接受心电图、D-二聚体诊断,探讨心电图、D-二聚体对急性肺栓塞患者诊断价值。结果心电图检测对急性肺栓塞患者检测阳性率为93.10%,显著高于对慢性支气管炎检测阳性率(P0.05);D-二聚体检测对急性肺栓塞患者检测阳性率为89.66%,显著高于对慢性支气管炎检测阳性率(P0.05)。结论心电图与D-二聚体在急性肺栓塞诊断中均具有重要的诊断价值。  相似文献   

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