The clinical course of pulmonary embolism.

BACKGROUND. Pulmonary embolism is a potentially fatal disorder. Information about the outcome of clinically recognized pulmonary embolism is sparse, particularly given that new treatments for more seriously ill patients are now available. METHODS. We prospectively followed 399 patients with pulmonary embolism diagnosed by lung scanning and pulmonary angiography, who were enrolled in a multicenter diagnostic trial. We reviewed all hospitalizations, all new investigations of pulmonary embolism, and all deaths among the patients within one year of diagnosis. RESULTS. Of the 399 patients, 375 (94 percent) received treatment for pulmonary embolism, usually conventional anticoagulation. Only 10 patients (2.5 percent) died of pulmonary embolism; 9 of them had clinically suspected recurrent pulmonary embolism. Clinically apparent pulmonary embolism recurred in 33 patients (8.3 percent), of whom 45 percent died during follow-up. Ninety-five patients with pulmonary embolism (23.8 percent) died within one year. The conditions associated with these deaths were cancer (relative risk, 3.8; 95 percent confidence interval, 2.3 to 6.4), left-sided congestive heart failure (relative risk, 2.7; 95 percent confidence interval, 1.5 to 4.6), and chronic lung disease (relative risk, 2.2; 95 percent confidence interval, 1.2 to 4.0). The most frequent causes of death in patients with pulmonary embolism were cancer (in 34.7 percent), infection (22.1 percent), and cardiac disease (16.8 percent). CONCLUSIONS. When properly diagnosed and treated, clinically apparent pulmonary embolism was an uncommon cause of death, and it recurred in only a small minority of patients. Most deaths were due to underlying diseases. Patients with pulmonary embolism who had cancer, congestive heart failure, or chronic lung disease had a higher risk of dying within one year than did other patients with pulmonary embolism.     

D-dimer testing: the role of the clinical laboratory in the diagnosis of pulmonary embolism

Pulmonary embolism is a common, yet often unsuspected and unrecognised disease associated with a high mortality. New, objective, "user friendly" and cost effective diagnostic strategies are being explored. D-dimers, the fibrinolytic degradation products of crosslinked fibrin, have emerged as the most useful of the procoagulant activity and ongoing fibrinolysis markers. D-dimer measurements are very sensitive in excluding a diagnosis of pulmonary embolism in the setting of normal values, a low clinical suspicion, and non-diagnostic lung scans. Several assays have been developed and are reviewed.     

肺动脉栓塞定位诊断的实验性研究

目的： 评价［99mTc］标记的抗纤维蛋白D-二聚体单抗诊断实验性的兔肺动脉血栓栓塞的敏感性、特异性和最佳显像时间。方法： 新西兰白兔30只，分为血栓栓塞组和正常对照组，血栓栓塞组建立肺动脉血栓栓塞模型。将［99mTc］标记的抗D-二聚体单抗注入实验动物体内，以放射免疫显像技术检测放射性核素在兔双肺的分布，计算血栓栓子影像感兴趣区与对侧感兴趣区的放射性计数比值。盲法阅片并与尸检结果相对比计算诊断的敏感性和特异性。结果： ［99mTc］标记的抗D-二聚体单抗注入实验动物体内10 min和30 min后，血栓栓塞组双肺局部均出现放射性核素的浓集，血栓栓子影像感兴趣区与对侧感兴趣区放射性计数比值如下：叶动脉组为2.84±0.52、2.75±0.67，段动脉组为2.59±0.38、2.61±0.36，亚段动脉组为2.19±0.32、2.20±0.28。两位研究者独立盲法阅片，各自诊断PE的敏感性和特异性分别为76.3%、80.0%和78.9%、72.7%，联合诊断肺栓塞的敏感性和特异性分别为84.2%和80.0%。两位研究者联合阅片诊断各组肺栓塞的敏感性为：叶动脉组91%，段动脉组85.7%，亚段动脉组76.9%。结论： ［99mTc］标记抗D-二聚体单抗可对实验性兔的肺动脉血栓栓塞模型作出诊断，此法具有较高的敏感性和特异性，且具有快速、准确、无创等特点。     

多层螺旋CT在肺动脉栓塞诊断中的应用

目的:探讨多层螺旋CT(MSCT)在肺动脉栓塞诊断中的价值.方法:回顾性分析我院12例诊断为肺栓塞的患者,均用美国GE16排螺旋CT机进行双期扫描后,将获得数据传至工作站进行后处理,观察肺动脉栓塞的直接和间接征象及栓塞血管级别.结果:MSCT可清晰地显示肺栓塞直接和间接征象及栓塞血管分级.结论:MSCT扫描速度快,空间分辨率高并且强大的图像后处理功能,在肺栓塞的诊断中能提供非常精确的信息,有望成为肺栓塞诊断中的最佳手段之一.     

Value of electrocardiography in the diagnosis of acute pulmonary embolism

Diagnosis of acute pulmonary embolism is difficult. The aim of the study was analysis of electrocardiographic (ECG) changes in patients with acute pulmonary embolism and analysis of correlations between electrocardiographic changes and pulmonary angiography and pulmonary artery pressure. ECG in 22 patients aged 47 +/- 13 years old (9 women and 13 men) with confirmed pulmonary embolism and without pre-existing cardiorespiratory diseases were analyzed. Most frequently tachycardia, negative T wave in III, aVF and precordial leads, dextrogyria and dextrogram in ECG were observed. In 20 patients 3 or more criteria were found. Index Milleri--an quantitative method of estimation of pulmonary embolism correlated with pulmonary artery pressure. Conclusion of this study is that ECG is one of the important diagnostic tests in patients with pulmonary embolism: it gives us information about changes in pulmonary arteries.     

Fibrin degradation product D-dimer in the diagnosis of pulmonary embolism

Summary The study objective was to determine the specificity and sensitivity of plasma concentrations of D-dimer, a fibrin degradation product, as a marker for ongoing thrombotic and thrombolytic events in pulmonary embolism. A prospective study was performed in 74 patients with suspected pulmonary embolism who appeared in the emergency room with dyspnea and/or chest pain.The presence of pulmonary embolism was established by positive findings either in pulmonary angiography or lung scan. D-dimer concentrations were determined in all patients. In 11 patients with positive pulmonary angiography, D-dimer concentrations were monitored for 6–12 days.D-dimer concentrations were determined by a quantitative enzyme-linked immunoassay. Plasma probes of 26 patients (16 with/10 without positive pulmonary angiography) were reassayed with a semiquantitative latex agglutination assay. D-dimer levels were significantly higher in patients with pulmonary embolism (>1000 ng/mL in 41 out of 43) than in those without (<1000 ng/mL in all 21 patients) (p<0.01).The sensitivity and specificity for the ELISA were found to be 95% and 100%, respectively, for establishing the diagnosis of pulmonary embolism. In the latex assay the values were 81% and 60%, respectively.It is concluded that in patients with dyspnea and/or chest pain, determination of D-dimer in plasma by ELISA adds a valuable tool to the noninvasive diagnostic procedure for pulmonary embolism. From the time-course of D-dimer values we conclude that this assay might be valuable up to at least 6 days after symptom onset. The assay, however, is unreliable in malignancies or after surgery.Abbreviations apPE angiographically proven pulmonary embolism - hpPE highly probable pulmonary embolism - imPE highly improbable pulmonary embolism - rPE pulmonary embolism ruled out - pPE possible pulmonary embolism     

Relevance of postmortem radiology to the diagnosis of fatal cerebral gas embolism from compressed air diving

AIMS: To test the hypothesis that artefact caused by postmortem off-gassing is at least partly responsible for the presence of gas within the vascular system and tissues of the cadaver following death associated with compressed air diving. METHODS: Controlled experiment sacrificing sheep after a period of simulated diving in a hyperbaric chamber and carrying out sequential postmortem computed tomography (CT) on the cadavers. RESULTS: All the subject sheep developed significant quantities of gas in the vascular system within 24 hours, as demonstrated by CT and necropsy, while the control animals did not. CONCLUSIONS: The presence of gas in the vascular system of human cadavers following diving associated fatalities is to be expected, and is not necessarily connected with gas embolism following pulmonary barotrauma, as has previously been claimed.