Incremental value of pocket-sized imaging device for bedside diagnosis of unilateral pleural effusions and ultrasound-guided thoracentesis

OBJECTIVES: The present study aimed to assess the additional value of a pocket-sized imaging device (PSID) as an adjunct to plain chest X-rays in the diagnosis of pleural effusion (PE), mainly for those requiring pleural thoracentesis. METHODS: We performed a thoracic ultrasound examination using a PSID in 73 patients with an abnormal chest X-ray diagnostic for unilateral PE. Abundant PE was defined as an interpleural distance between the diaphragm and visceral pleura (VP) of ≥ 30 mm at the apex of the 50 mm bisector line of the costodiaphragmatic recess at end expiration. RESULTS: According to PSID ultrasound evaluation, abundant PE was present in 46 patients (63%), while 27 (37%) patients showed the presence of mild PE or absence of PE. Thoracentesis was performed successfully and without procedure-induced complications in all 46 patients with abundant PE. Using the above-mentioned method, we obtained a high diagnostic accuracy (area under the curve = 0.99) and excellent sensitivity and specificity of 91.7 and 99.9%, respectively, to predict a PE >1000 ml, when VP was >6.3 cm. CONCLUSIONS: PSID is a useful tool that may integrate and complete the physical examination, also providing additional information to chest X-ray in the clinical management of patients with suspected PE. PSID evaluation can also increase the effectiveness and safety of thoracentesis.