158.A 26-year-old woman, who was a belted front-seat driver in a head-
on motor vehicle collision, is brought to the ED. She is speaking but com-
plains of progressively worsening shortness of breath and hemoptysis. Her
BP is 135/75 mm Hg, HR is 111 beats per minute, RR is 24 breaths per
minute, and oxygen saturation is 96% on non-rebreather. On examination,
you note ecchymosis over the right side of her chest. Her breath sounds are
equal bilaterally. There is no bony crepitus and the trachea is midline. After
placing two large-bore IVs and completing the primary and secondary sur-
veys, you view the chest radiograph seen below. Which of the following is
the most likely diagnosis?
144 Emergency Medicine
a. Diaphragm rupture
b. Hemothorax
c. Tension pneumothorax (PTX)
d. Pulmonary contusion
e. Acute respiratory distress syndrome (ARDS)