A 23-year-old woman is brought to the emergency department with a chest wound. She was in her house during a severe thunderstorm when a large tree branch fell through a window. The window was shattered and large fragments of wood and glass struck the patient. She did not lose consciousness, but her family found her bleeding profusely and rushed her to the hospital. Blood pressure is 80/50 mm Hg and pulse is 130/min. The patient appears to be in severe distress. Physical examination shows a deep penetrating wound in the fourth intercostal space along the left sternal border. Smaller lacerations are noted across the face and forearms. Which of the following structures is most likely injured in this patient?

Question

A 23-year-old woman is brought to the emergency department with a chest wound.  She was in her house during a severe thunderstorm when a large tree branch fell through a window.  The window was shattered and large fragments of wood and glass struck the patient.  She did not lose consciousness, but her family found her bleeding profusely and rushed her to the hospital.  Blood pressure is 80/50 mm Hg and pulse is 130/min.  The patient appears to be in severe distress.  Physical examination shows a deep penetrating wound in the fourth intercostal space along the left sternal border.  Smaller lacerations are noted across the face and forearms.  Which of the following structures is most likely injured in this patient?

Quizplus · Accepted Answer

11ec160b_355e_f72e_9249_29ee7cb0a2fa_MD0001_00 A penetrating injury at the left sternal border in the fourth intercostal space (level of the nipple) will pass through the following layers (in order): The right ventricle composes the majority of the anterior surface of the heart and is at risk of injury with penetrating trauma at the mid- and lower-left sternal border. The parietal pleura would be injured as well, but the left lung itself would not be punctured as there is no middle lobe on the left side, and the superior lobe of the left lung is displaced laterally by the cardiac impression. (Choice A) The inferior vena cava (IVC) passes through the right side of the central tendon of the diaphragm at the level of T8. A penetrating wound to the back at the immediate right of the vertebral bodies could strike the IVC. (Choice B) The left atrium is located at the base of the heart (posterior surface, opposite the apex) and makes up most of the heart's posterior surface. Only the auricle of the left atrium is visible anteriorly (protruding between the pulmonary trunk and the left ventricle). (Choice C) The left ventricle composes the left lateral aspect of the heart. A stab wound angled slightly medially in the fourth intercostal space at the midclavicular line could strike the left ventricle, but only after passing through the bulk of the left lung. (Choice D) The pulmonary trunk could be pierced by a penetrating injury to the second intercostal space at the left sternal border. Educational objective: The right ventricle composes most of the heart's anterior surface. A deep, penetrating injury at the left sternal border in the fourth intercostal space would puncture the right ventricle.

A 23-Year-Old Woman Is Brought to the Emergency Department with a Chest