A 56-year-old woman is brought to the hospital from a local restaurant after suddenly becoming short of breath. Her pulmonary flow-volume loop is shown below. Which of the following is the most likely cause of her symptoms?

Question

A 56-year-old woman is brought to the hospital from a local restaurant after suddenly becoming short of breath.  Her pulmonary flow-volume loop is shown below.  Which of the following is the most likely cause of her symptoms?

Quizplus · Accepted Answer

11ec25c8_d4cd_d9fc_bc81_97b5896150b4_MD0003_00 This patient's pulmonary flow-volume loop is characteristic of a fixed upper-airway obstruction. The obstruction limits airflow during inspiration and expiration, causing flattening of the top and bottom of the flow-volume curve. Because her symptoms started in a restaurant, this patient most likely developed laryngeal edema secondary to a food allergy. Therefore, she requires treatment with epinephrine, systemic corticosteroids, and antihistamines. (Choice A) Asthma causes intrapulmonary airway obstruction via bronchoconstriction. This decreases airflow during the effort-independent phase of exhalation, causing flow-volume loops to have a "scooped-out" pattern during exhalation. "scooped-out" pattern (Choice C) A panic attack will not decrease the flow rate during passive expiration or inspiration; flow-volume loops will be normal. (Choices D and E) Pneumothorax decreases lung ventilation by preventing complete expansion of the affected lung. Pulmonary edema will also decrease lung ventilation by reducing pulmonary compliance. These conditions cause a restrictive pattern that is characterized by decreased lung volumes with expiratory flow rates that are increased relative to the low lung volumes. restrictive pattern Educational objective: A fixed upper-airway obstruction will decrease the airflow rate during inspiration and expiration, flattening both the top and bottom of the flow-volume loop.

A 56-Year-Old Woman Is Brought to the Hospital from a Local