Large pleural effusion on POCUS Echocardiogram - Parasternal Long Axis On parasternal long axis, use the descending thoracic aorta (shown here in red) to aid you in differentiation. Pleural effusions track behind the aorta, pericardial effusions track above it. Eric Abrams, MD @eabramsMD #pleural #effusion #POCUS #Echocardiogram #PLAX #clinical