The case:
A motorcyclist is minding his own business, stationary at a set of lights and is rear-ended by a car at ~60-70km/h. He is thrown 10 meters or so from his bike and lands on his left side. Remarkably he is systemically well, except for significant left lateral chest wall pain !!
You think he has reduced air-entry on the left side, but is he’s not dyspnoeic, nor hypoxic. The remainder of his primary survey is unremarkable.
This is his supine CXR…
EFAST showed no evidence of free intraperitoneal fluid, but this is what I saw on the chest….