Point of care multi-organ ultrasonography is an accurate tool to diagnose pulmonary embolism in the emergency department and may reduce the number of patients that undergo computed tomography

Abstract

Purpose: Use of single organ goal-directed ultrasound (US) of the heart, leg veins and lung showed low sensitivity for the diagnosis of pulmonary embolism (PE). Present study investigated the accuracy of multi-organ US protocol that combines heart, leg veins and lung studies for the diagnosis of PE and evaluated if multi-organ US combined with d-dimer level could reduce multi-detector computed tomography pulmonary angiography (MCTPA) rate in suspected PE. Mehods: Consecutive adult patients presenting to three Emergency Departments with suspected PE and Wells score>4 or a positive D-dimer (>500ng/ml), were prospectively investigated. Final diagnosis was obtained with MCTPA or autopsy. Multi-organ US was considered diagnostic for PE when at least one of the following was detected: deep leg veins thrombosis, right ventricle dilatation, one or more subpleural infarcts. In patients with negative multi-organ US for PE, an alternative US diagnosis such as pneumonia, pleural effusion, diffuse interstitial syndrome, pericardial effusion or aortic dissection was also researched. Accuracies of each single and multi-organ US were calculated. Results: PE was diagnosed in 110 (30.8%) out of 357 patients. Heart US showed a sensitivity of 32.7% and a specificity of 90.9%, leg veins US 52.7% and 97.6%, lung US 60.9% and 95.9% and multi-organ US 90% and 86.2% respectively. Among the 224 patients with multi-organ US negative for PE, an alternative US diagnosis was detected in 106 (47.3%) and a negative d-dimer was present in 50 (22.3%). No patients with multi-organ US negative for PE plus an alternative US diagnosis or plus a negative d-dimer (37% of the overall population) had PE as final diagnosis (sensitivity 100%). Conclusion: Multi-organ US sensitivity for PE is superior to all single organ goal-directed US. A strategy combining multi-organ US negative for PE with the detection of an alternative US diagnosis or a negative d-dimer might safely rule out PE and might reduce of one third the rate of patients that normally undergo MCTPA.