The association of pleural effusion and pulmonary embolism

Editor – When pleural effusion occurs as a manifestation of pulmonary embolism, this occurrence should generate an opportunity to implement the ultrasonographic pathway for the workup of suspected pulmonary embolism.¹ The first step in that pathway is to perform thoracic ultrasound (TUS) to ascertain whether or not the pleural effusion is attributable to pulmonary infarction. On ultrasonography, the majority of pulmonary infarcts are wedge shaped, but some may either be round or polygonal. Colour Doppler distinguishes pulmonary infarcts from lesions attributable to pneumonia, metastasis or peripheral lung mass.²

Ultrasonographic evaluation of all four limbs (for deep vein thrombosis (DVT)) should be the next step in the ultrasonographic pathway. The association of proven DVT and TUS-validated pulmonary infarction should suffice to justify initiation of anticoagulant therapy, thereby obviating the need for further imaging by computed tomography and angiography. That ‘short cut’ strategy would be uniquely applicable to the hypothetical patient in Ramjug and Phillips’ vignette if his chest pain was pleuritic in nature because, in the context of suspected pulmonary embolism, patients with pleuritic chest pain are the ones most likely to have identifiable pulmonary infarcts on TUS.