A Way to Select on Clinical Grounds Patients with High Risk for Pulmonary Embolism: A Retrospective Analysis in a Nested Case-Control Study

Abstract

We studied 196 patients with suspicion of pulmonary embolism (PE), subsequently confirmed in 98 by positive pulmonary angiography and excluded in 98 by normal or near-normal perfusion lung scan. Patients had a clinical questionnaire for history, and, soon after, a radiograph, blood gas analysis, and an ECG. Clinical and instrumental signs were matched in patients with confirmed and unconfirmed PE to find those more frequent in embolic patients and, thus, more characteristic of PE. The following were: previous PE, immobilization and thrombophlebitis (p < 0.05); dyspnea and cough (p < 0.05); enlarged descending pulmonary artery (DPA), enlarged right heart, pulmonary infarction, Westermark sign (p < 0.001), and elevated diaphragm (p < 0.05); hypoxemia. No ECG sign was more frequent in PE. Thereafter, all variables were processed separately with a logistic multiple regression analysis and those significantly associated to PE were tested in a final logistic model that was able to predict the actual result of angiography or scintigraphy; accordingly, previous PE, immobilization, thrombophlebitis, enlarged DP A, pulmonary infarction, Westermark sign, hypoxemia were significantly associated with a high risk of PE (from 2.8 to 15 times greater than in patients without these signs). Therefore, we may conclude that clinical assessment and noninvasive tests may help to detect patients at higher risk for PE where heparin coverage should be started while waiting for conclusive diagnostic procedures.

Is atrial fibrillation associated with pulmonary embolism?

“…First, sample size was probably insufficient given the low prevalence of AF in case of PE. Second, all but one study [15] suffered from a lack of adjustments for main confounding factors. Finally, as these studies included patients with PE suspicion only, selection bias could have occurred.…”

Prediction of right ventricular dysfunction from radiographic estimates of right descending pulmonary artery in hemodynamically stable pulmonary embolism patients

“…Both RV diameter and the end-diastolic RV/LV ratio had a signifi cant association with the diameter of right descending pulmonary artery on chest X-rays. An enlarged right descending pulmonary artery was matched in patients with confi rmed and unconfi rmed PE and has been more frequently seen in embolic patients in literature [24]. Previously it has also been shown that there is an association between the diameter of the right descending pulmonary artery and pulmonary hypertension as revealed by right heart catheterization and by echocardiography [17,25].…”

Acute pulmonary embolism in patients with HIV disease

“…In these case matched patients we sought evidence, by case note review, of the presence of major risk factors for venous thromboembolism. [2][3][4][5] The presence of risk factors for thromboembolism was compared in HIV infected patients with and without pulmonary embolism by means of an odds ratio using a Mantel-Haenszel estimate. 8…”

“…1 Several major risk factors for venous thromboembolism have been identified including recent abdominal surgery, disseminated malignancy, previous venous thromboembolism, immobilisation for more than 1 week, disabling cardiorespiratory disease, age >40 years, and thrombotic disorders. [2][3][4][5] In contrast, reports of pulmonary embolism in HIV infected individuals are scarce, despite descriptions of the hypercoagulable state due to HIV associated lupus anticoagulant, anticardiolipin antibodies, and protein S deficiency. 6 Diagnosis of acute pulmonary embolism may be diYcult and usually relies on a strong clinical history with supportive imaging, most often a ventilation/perfusion (V/Q) scan.…”