血浆D-二聚体对疑似肺栓塞患者诊断价值的研究

目的：探讨血浆 D-二聚体对对疑似肺栓塞患者的诊断价值。方法采用自动化免疫比浊法测定患者血浆D-二聚体水平。统计分析血浆D-二聚体诊断肺栓塞的敏感性、特异性、阴性及阳性预测值,并绘制ROC曲线以评价其诊断价值并对D-二聚体阴性排除肺栓塞价值进行分析。结果在317例疑似肺栓塞患者中D-二聚体＜500μg/L的患者73例,其中6例被诊断为肺栓塞。D-二聚体对肺栓塞的诊断的敏感性为95.86%（95%CI：91.27%～98.08%）,特异性为38.95%（95%CI：31.98%～41.41%）,阴性预测值为91.78%（95%CI：83.21%～96.18%）,阳性预测值为56.97%（95%CI：50.69%～63.02%）,诊断准确性为64.98%（95%CI：59.58%～70.03%）。ROC曲线下面积为0.674（95%CI：0.615～0.733）。结论 D-二聚体对肺栓塞的诊断具有较高的敏感性,阴性排除肺栓塞的准确性较高,但仍可受患者年龄、测试方法等的影响。     

Capnometry in suspected pulmonary embolism with positive D-dimer in the field

Introduction  

Pulmonary embolism (PE) is one of the greatest diagnostic challenges in prehospital emergency setting. Most patients with suspected PE have a positive D-dimer and undergo diagnostic testing. Excluding PE with additional non-invasive tests would reduce the need for further imaging tests. We aimed to determine the effectiveness of combination of clinical probability and end-tidal carbon dioxide (PetCO₂) for evaluation of suspected PE with abnormal concentrations of D-dimer in prehospital emergency setting.     

How ECG can cause confusion in pulmonary embolism and how echocardiogram can help

A case of pulmonary embolism in which the diagnosis was aided by transthorasic echocardiography is described. Echocardiography may be helpful in emergency presentations, as ECG changes can be neither sensitive nor specific for the diagnosis of acute massive pulmonary embolism.     

Clinical probability and alveolar dead space measurement for suspected pulmonary embolism in patients with an abnormal D-dimer test result

BACKGROUND: Most patients with suspected pulmonary embolism (PE) have a positive D-dimer test and undergo diagnostic imaging. Additional non-invasive bedside tests are required to reduce the need for further diagnostic tests. OBJECTIVES: We aimed to determine whether a combination of clinical probability assessment and alveolar dead space fraction measurement can confirm or exclude PE in patients with an abnormal D-dimer test. METHODS: We assessed clinical probability of PE and alveolar dead space fraction in 270 consecutive in- and outpatients with suspected PE and positive D-dimer. An alveolar dead space fraction < 0.15 was considered normal. PE was subsequently excluded or confirmed by venous compression ultrasonography, spiral computed tomography and a 3-month follow-up. Radiologists were unaware of the results of clinical probability and capnography. RESULTS: PE was confirmed in 108 patients (40%). Capnography had a sensitivity of 68.5% (95% confidence interval [CI]: 58.9-77.1%) and a specificity of 81.5% (95% CI: 74.6-87.1%) for PE. Forty-five patients (16.6%) had both a low clinical probability and normal capnography (sensitivity: 99.1%, 95% CI: 94.9-100%) and 34 patients (12.6%) had both a high clinical probability and abnormal capnography (specificity: 100%, 95% CI: 97.7-100%). CONCLUSION: Capnography alone does not exclude PE accurately. The combination of clinical probability and capnography accurately excludes or confirms PE and avoids further testing in up to 30% of patients.     

Comparison of diagnostic accuracies in outpatients and hospitalized patients of D-dimer testing for the evaluation of suspected pulmonary embolism

BACKGROUND: The ability of various D-dimer assays to exclude the diagnosis of thromboembolic diseases is controversial. We examined the diagnostic accuracy of two D-dimer methods in hospitalized patients and outpatients. METHODS: We studied consecutive patients for whom D-dimer testing was ordered for investigation of suspected pulmonary embolism. We measured D-dimer by an ELISA (VIDAS D-dimer) and an enhanced microlatex immunoassay method (Diagnostica Stago STA Liatest D-di). Patient diagnoses were based on imaging studies or, when these were not performed, on follow-up by review of medical records 3 months later. RESULTS: We examined 233 hospitalized patients and 234 outpatients with a mean age of 58 years (range, 1-92 years) and a female-to-male ratio of 1.4 to 1. Thromboembolism was present in 8% of outpatients and 12% of hospitalized patients. In outpatients, the negative predictive values were 98% [95% confidence interval (CI), 93-100%] and 99% (94-100%) for the microlatex and ELISA methods, respectively, at the recommended cutoffs. Areas under the ROC curves were similar for the two methods [0.77 (95% CI, 0.67-0.87) and 0.81 (0.73-0.89), respectively]. By contrast, in hospitalized patients, the confidence intervals for the areas under the ROC curves included 0.5 [0.60 (95% CI, 0.50-0.71) and 0.56 (0.44-0.67)]. CONCLUSIONS: For hospitalized patients, in contrast to outpatients, the diagnostic accuracy of D-dimer testing for pulmonary embolism is poor in a tertiary care setting, presumably reflecting thrombosis and comorbidities, other than pulmonary embolism, that increase the D-dimer concentrations in these patients. The patient population studied appears more important than assay method in studies of the diagnostic accuracy of D-dimer testing.     

D-Dimer test in cancer patients with suspected acute pulmonary embolism

BACKGROUND: The safety of a D-dimer (DD) measurement in cancer patients with clinically suspected pulmonary embolism (PE) is unclear. OBJECTIVES: The aim of this study was to assess the accuracy of the DD test in consecutive patients with clinically suspected PE with and without cancer. METHODS: The diagnostic accuracy of DD (Tinaquant D-dimer) was first retrospectively assessed in an unselected group of patients referred for suspected PE (n = 350). Subsequently, the predictive value of the DD was validated in a group of consecutive inpatients and outpatients with clinically suspected PE prospectively enrolled in a management study (n = 519). The results of the DD test in cancer patients were assessed according to the final diagnosis of PE and the 3-month clinical follow-up. RESULTS: In the first study group, DD showed a sensitivity and a negative predictive value (NPV) of 100% and 100% in patients with cancer and 97% and 98% in those without malignancy, respectively. In the validation cohort, the sensitivity and NPV of DD were both 100% (95% CI 82%-100% and 72%-100%, respectively), whereas in patients without malignancy, the corresponding estimates were 93% (95% CI 87%-98%) and 97% (95% CI, 95%-99%), respectively. The specificity of DD was low in patients with (21%) and without cancer (53%). CONCLUSIONS: A negative DD result safely excludes the diagnosis of PE in patients with cancer. Because of the low specificity, when testing 100 patients with suspected PE, a normal DD concentration safely excludes PE in 15 patients with cancer and in 43 patients without cancer.     

Diagnostic utility of echocardiography in patients with suspected pulmonary embolism

The aim of this study was to investigate the clinical utility of echocardiography in the diagnosis of pulmonary embolism (PE). For this, we enrolled 162 patients with suspected PE in a prospective study. We evaluated the sensitivity and specificity of right ventricular dilatation, the Doppler evidence of pulmonary hypertension, and their possible associations. We also calculated the number of lung-scan angiography procedures avoided and the number of patients unnecessarily treated when echocardiography was included in the diagnostic work-up. The sensitivity and specificity of echocardiography ranged between 29 and 52% and between 96% and 87%, respectively. Adding echocardiography to the diagnostic strategy for PE would avoid about 12 to 28% of lung-scan angiography procedures, but would cause inappropriate treatment of 4 to 14% of all treated patients. The clinical utility of echocardiography in the diagnosis of PE is limited. The reduction in the number of standard diagnostic procedures obtained through its use would be counterbalanced by an excess of patients inappropriately treated.     

Diagnostic variability in suspected pulmonary embolism

Over a 12-month period, we observed adult patients with suspected pulmonary embolism referred for lung scanning to determine variability in the diagnostic process. Among 269 studies, 157 lung scans were judged necessary by predetermined criteria. Ninety-three of these 157 patients had inconclusive results (low probability, intermediate probability, or indeterminate). Of these 93 patients, 42 had pulmonary angiograms, ten of which were positive. Of the 51 patients with necessary but inconclusive scans, five were poor candidates for angiography, 15 had other indications for anticoagulation, seven refused the study, and 24 had physicians who considered further studies unwarranted. Patients with and without pulmonary angiography were demographically and clinically similar. Although confirmatory testing such as pulmonary angiography was used frequently (45%) after an inconclusive lung scan, the question of pulmonary embolism was often left unanswered (55%). Methods for linking clinical judgment to lung scan results are necessary to select proper patients for invasive confirmatory testing.     

Comprehensive evaluation of CT pulmonary angiography for patients suspected of having pulmonary embolism

Many apparent healthy persons die from cardiovascular disease, despite major advances in prevention and treatment of cardiovascular disease. Traditional cardiovascular risk factors are able to predict cardiovascular events in the long run, but fail to assess current disease activity or nearby cardiovascular events. There is a clear relation between the occurrence of cardiovascular events and the presence of so-called vulnerable plaques. These vulnerable plaques are characterized by active inflammation, a thin cap and a large lipid pool. Spectroscopy is an optical imaging technique which depicts the interaction between light and tissues, and thereby shows the biochemical composition of tissues. In recent years, impressive advances have been made in spectroscopy technology and intravascular spectroscopy is able to assess the composition of plaques of interest and thereby to identify and actually quantify plaque vulnerability. This review summarizes the current evidence for spectroscopy as a measure of plaque vulnerability and discusses the potential role of intravascular spectroscopic imaging techniques.     

D-二聚体阴性肺栓塞患者的临床特点

目的 归纳总结D-二聚体阴性(D-二聚体＜0.5μg/mL)的肺栓塞患者的临床特点,从而提高肺栓塞诊断准确率、降低肺栓塞的病死率。方法 对南京医科大学第一附属医院2006年1月至2009年12月收治的D-二聚体阴性的疑似肺栓塞患者的危险因素、临床特征及辅助检查进行回顾分析,将16例最终确诊肺血栓栓塞症患者与同期排除肺栓塞的41例疑似患者的临床特点进行比较,采用t检验及四格表Fisher确切概率法比较各组间临床表现、生命体征及辅助检查结果的差异。结果 D-二聚体阴性的肺栓组与非病例组相比,既往有VTE病史、有近期手术史者更易于发病,胸闷、呼吸困难常见,病例组呼吸频率高于对照组,病例组下肢水肿较对照组多见,心电图典型ECG SI QⅢTⅢ改变多见。结论D-二聚体作为急性肺栓塞筛选检查,其阴性预测值较高,但当患者出现进行性呼吸困难、下肢水肿、既往有VTE病史、有近期手术史、心电图出现SIQⅢTⅢ改变时,即使D-二聚体阴性,临床工作者也需引起重视,必要时可考虑进一步检查以排查有无肺栓塞。     

Clinical probability and risk analysis of patients with suspected pulmonary embolism

BACKGROUND:

Pulmonary embolism (PE) is one of the most frequent diseases that could be missed in overcrowded emergency departments as in Turkey. Early and accurate diagnosis could decrease the mortality rate and this standard algorithm should be defined. This study is to find the accurate, fast, non-invasive, cost-effective, easy-to-access diagnostic tests, clinical scoring systems and the patients who should be tested for clinical diagnosis of PE in emergency department.

METHODS:

One hundred and forty patients admitted to the emergency department with the final diagnosis of PE regarding to anamnesis, physical examination and risk factors, were included in this prospective, cross-sectional study. The patients with a diagnosis of pulmonary embolism, acute coronary syndrome or infection and chronic obstructive pulmonary disease (COPD) were excluded from the study. The demographics, risk factors, radiological findings, vital signs, symptoms, physical-laboratory findings, diagnostic tests and clinical scoring systems of patients (Wells and Geneva) were noted. The diagnostic criteria for pulmonary emboli were: filling defect in the pulmonary artery lumen on spiral computed tomographic angiography and perfusion defect on perfusion scintigraphy.

RESULTS:

Totally, 90 (64%) of the patients had PE. Age, hypotension, having deep vein thrombosis were the risk factors, and oxygen saturation, shock index, BNP, troponin and fibrinogen levels as for the biochemical parameters were significantly different between the PE (+) and PE (−) groups (P<0.05). The Wells scoring system was more successful than the other scoring systems.

CONCLUSION:

Biochemical parameters, clinical findings, and scoring systems, when used altogether, can contribute to the diagnosis of PE.KEY WORDS: Pulmonary embolism, Probability, Emergency department     

D-二聚体检测在胸外科患者术后肺栓塞中的诊断价值

目的探讨D-二聚体检测在胸外科患者术后肺栓塞中的诊断价值。方法回顾性分析2008年-2013年期间我院收治的18 128例胸外科手术治疗患者术后发生肺栓塞的临床资料,并选取其中的35例胸外科手术治疗患者进行D-二聚体检测。结果胸外科手术年龄≧50岁的患者与〈50岁的患者比较,肥胖患者与体重合格者比较,发生恶性肿瘤与良性肿瘤比较,肺栓塞发生率均有显著性差异（P〈0.05）;进行D-二聚体检测诊断肺栓塞的阴性预测值以及敏感性均为100%,假阳性率为94.7%（18/19）。结论行胸外科手术治疗的肥胖、高龄和恶性肿瘤患者术后发生肺栓塞的可能性较大,而采用D-二聚体检测,能够较精确地对肺栓塞进行诊断,阴性结果正确率高,值得临床上进一步推广与研究。     

Exclusion of pulmonary embolism using quantitative plasma D-dimer assays

Recent quantitative studies using pulmonary angiography as reference method have indicated that the overall accuracy of quantitative D-dimer assays for the exclusion of pulmonary embolism (PE) in patients suspected of PE is poorer than was reported in earlier studies in which the same D-dimer assays were used (90-94% vs 98-100%). An explanation can be found in the fact that the earlier studies are hampered by the fact that the reference method was a compilation of clinical data and non-invasive diagnostic tests rather than a true gold standard. Furthermore, in those studies no discrimination was made between the milder cases of subsegmental PE and the more severe cases of segmental and larger PE. The lack of a true gold standard and preselection leading to reduced proportions of cases of subsegmental PE in the earlier studies rather than differences in the storage conditions of plasma samples or treatment with heparin, appear to have caused the discrepancies in the reported accuracy of D-dimer assays. It is concluded that the sensitivity and negative predictive values obtained with different quantitative D-dimer assays are in close agreement with each other, that is poor for subsegmental PE and excellent for segmental and larger PE. In diagnostic algorithms D-dimer can reliably exclude acute segmental and/or massive PE. Further work-up within 48 hours is still necessary in negative D-dimer outcomes to exclude subsegmental PE.     

Diagnostic management of clinically suspected acute pulmonary embolism

Summary.  Current diagnostic management of hemodynamically stable patients with clinically suspected acute pulmonary embolism (PE) consists of the accurate and rapid distinction between the approximate 20–25% of patients who have acute PE and require anticoagulant treatment, and the overall majority of patients who do not have the disease in question. Clinical outcome studies have demonstrated that, using algorithms with sequential diagnostic tests, PE can be safely ruled out in patients with a clinical probability indicating PE to be unlikely and a normal D-dimer test result. This obviates the need for additional radiological imaging tests in 20–40% of patients. CT pulmonary angiography (CTPA) has become the first line tool to confirm or exclude the diagnosis of PE in patients with a likely probability of PE or an elevated D-dimer blood concentration. While single-row-detector technology CTPA has a low sensitivity for PE and bilateral compression ultrasound (CUS) of the lower limbs is considered necessary to rule out PE, multi-row-detector CTPA is safe to exclude PE without the confirmatory use of CUS.     

Compressive ultrasound can predict early pulmonary embolism onset in COVID patients

PurposeTo evaluate the usefulness of compressive ultrasound (CUS) for the diagnosis of deep vein thrombosis (DVT) in patients with SARS-CoV-2-related infection.Methods112 hospitalized patients with confirmed SARS-CoV-2 infection were retrospectively enrolled. CUS was performed within 2 days of admission and consisted in the assessment of the proximal and distal deep venous systems. Lack of compressibility, or direct identification of an endoluminal thrombus, were the criteria used for the diagnosis of DVT. Pulmonary embolism (PE) events were investigated at computed tomography pulmonary angiography (CTPA) within 5 days of follow-up. Logistic binary regression was computed to determine which clinical and radiological parameters were independently associated with PE onset.ResultsOverall, the incidence of DVT in our cohort was about 43%. The most common district involved was the left lower limb (68.7%) in comparison with the right one (58.3%) while the upper limbs were less frequently involved (4.2% the right one and 2.1% the left one, respectively). On both sides, the distal tract of the popliteal vein was the most common involved (50% right side and 45.8% left side). The presence of DVT in the distal tract of the right popliteal vein (OR = 2.444 95%CIs 1.084–16.624, p = 0.038), in the distal tract of the left popliteal vein (OR = 4.201 95%CIs 1.484–11.885, p = 0.007), and D-dimer values (OR = 2.122 95%CIs 1.030–5.495, p = 0.003) were independently associated with the onset on PE within 5 days.ConclusionsCUS should be considered a useful tool to discriminate which category of patients can develop PE within 5 days from admission.