Fig. 2

a Assessment, with a 13-MHz linear transducer, of the effusion in the lower aspect of the thorax on the posterior axillary line, visualizing the upper and lower ribs, intercostal space, pleural fluid, and diaphragm. b After verifying no interposition of vessels with color Doppler, needle puncture is performed; needle passage into the pleural cavity is visualized in real time. c Pleural fluid return is verified, in this case blood. d Passage of the guide toward the pleural cavity on the diaphragm