A 73 year-old male presents to the emergency department complaining of chest pain following an assault. The patient is alert and greets you when you enter the room to evaluate him. He has bilateral breath sounds, but you question if the right lung field sounds diminished as compared to the left. He has a strong radial pulse with a normal rate and a blood pressure of 123/84. He is oriented to person, place, and time. He lifts his gown to draw your attention to his left chest wall, where he reports being struck by an unknown assailant’s fists. His oxygen saturation is 98% on room air. He endorses a slight feeling of dyspnea, but says “it’s just because it hurts, doc.” He explains that it was a brief assault and he didn’t sustain any blows to his head.

He denies past medical history. His appendix was removed when he was a child. He takes no medications. He has no known allergies. A chest x-ray is performed: