An 18-year-old man is brought to the emergency department after falling and striking his chest. He had been playing an interactive video game when he lost his balance and hit his left chest against the coffee table. The patient now has moderate left-sided chest pain, worse with deep inspiration. He also feels lightheaded. On examination, the patient appears uncomfortable and is taking shallow breaths. Blood pressure is 88/50 mm Hg, pulse is 122/min, and respirations are 28/min. Jugular veins are flat. The trachea is midline. The left chest wall has intact, bruised skin and is exquisitely tender to palpation. Breath sounds are present on the right but diminished in the left lung base, which is dull to percussion. Heart sounds are normal without murmurs. The abdomen is soft, nondistended, and nontender. Which of the following is the most likely cause of this patient's condition?

Question

An 18-year-old man is brought to the emergency department after falling and striking his chest.  He had been playing an interactive video game when he lost his balance and hit his left chest against the coffee table.  The patient now has moderate left-sided chest pain, worse with deep inspiration.  He also feels lightheaded.  On examination, the patient appears uncomfortable and is taking shallow breaths.  Blood pressure is 88/50 mm Hg, pulse is 122/min, and respirations are 28/min.  Jugular veins are flat.  The trachea is midline.  The left chest wall has intact, bruised skin and is exquisitely tender to palpation.  Breath sounds are present on the right but diminished in the left lung base, which is dull to percussion.  Heart sounds are normal without murmurs.  The abdomen is soft, nondistended, and nontender.  Which of the following is the most likely cause of this patient's condition?

Quizplus · Accepted Answer

11ec25c8_d93f_d9ef_bc81_59ad9230331a_MD0003_00 This patient with isolated blunt chest trauma (eg, blow to the chest on the table) now has symptomatic hypotension (lightheadedness), tachycardia, and flat jugular veins, concerning for hypovolemic shock. Because each half of the chest can hold up to 40% of the circulating blood volume, large intrathoracic hemorrhage (eg, hemothorax) can lead to acute hemodynamic instability. Hemothorax (eg, diminished breath sounds, dullness to percussion) may result from injuries to large (eg, aorta, hilar vessels) or small intrathoracic structures (eg, intercostal blood vessels, lung parenchyma). Given this patient's pleuritic chest pain and exquisite chest wall tenderness to palpation, the most likely source is fractured ribs with intercostal vessel injury. Hemothorax is treated with tube thoracostomy, which is sufficient to resolve many cases, although if immediate chest tube output is >1,500 mL of blood, emergent surgical thoracotomy is indicated. (Choice A) Blunt chest trauma can transmit stretching, shearing, and torsional forces capable of tearing the aorta, which (if the tear is full-thickness) may cause massive hemothorax and hemorrhagic shock. However, this typically occurs after a more severe mechanism of rapid deceleration (eg, fall >3 m [10 ft], motor vehicle collision), and the aortic isthmus (rather than the ascending aorta) is the most commonly affected site. Ascending aortic involvement would likely have additional findings such as acute coronary syndrome, cardiac tamponade, or focal neurologic deficits (from cerebrovascular ischemia). aortic isthmus (Choice B) Bronchial rupture causes rapid leakage of air from the tracheobronchial tree into the pleural space and surrounding tissues, which can lead to respiratory distress. However, it classically has associated crepitus and a large pneumothorax, with hyperresonance (rather than dullness) on percussion. (Choices D and E) Unilateral diaphragmatic dysfunction due to phrenic nerve injury or traumatic diaphragmatic rupture can present with tachypnea, shallow breathing, and unilateral diminished breath sounds (due to decreased lung expansion). However, neither injury typically results in severe hypotension or tachycardia (ie, shock). Educational objective: Hypovolemic shock in the setting of blunt chest trauma is concerning for intrathoracic hemorrhage. Rib fractures (with intercostal vessel injury) are a common cause of hemothorax. References: Hemothorax: etiology, diagnosis, and management. (http://www.ncbi.nlm.nih.gov/pubmed/23206720) Thoracic trauma. (http://www.ncbi.nlm.nih.gov/pubmed/28958357)

An 18-Year-Old Man Is Brought to the Emergency Department After