A 32-year-old man comes to the urgent care clinic due to shortness of breath. Last week, He came with his family to the Mount Everest base camp at an elevation of 5,334 m (17,500 ft). He has had worsening dyspnea and cough. The patient now feels short of breath even with minimal exertion. Temperature is 37.3 C (99.1) F, blood pressure is 134/82 mm Hg, pulse is 98/min, and respirations are 22/min. Oxygen saturation is 86% on ambient air, which rapidly improves to 95% with supplemental oxygen. Physical examination shows pink mucous membranes, flat neck veins, bilateral inspiratory crackles, and no heart murmurs or pedal edema. Chest x-ray reveals patchy alveolar infiltrates. Which of the following is the most likely cause of this patient's current condition?

Question

A 32-year-old man comes to the urgent care clinic due to shortness of breath. Last week, He came with his family to the Mount Everest base camp at an elevation of 5,334 m (17,500 ft). He has had worsening dyspnea and cough.  The patient now feels short of breath even with minimal exertion.  Temperature is 37.3 C (99.1) F, blood pressure is 134/82 mm Hg, pulse is 98/min, and respirations are 22/min.  Oxygen saturation is 86% on ambient air, which rapidly improves to 95% with supplemental oxygen.  Physical examination shows pink mucous membranes, flat neck veins, bilateral inspiratory crackles, and no heart murmurs or pedal edema.  Chest x-ray reveals patchy alveolar infiltrates.  Which of the following is the most likely cause of this patient's current condition?

Quizplus · Accepted Answer

Eductional Objective: High-altitude pulmonary edema presents with dyspnea and cough within several days of arrival at high altitude.  It is driven by reduced ambient oxygen, which leads to hypoxic pulmonary vasoconstriction and pulmonary arterial hypertension.  Individuals with unevenly distributed pulmonary vasoconstriction can develop areas of high capillary perfusion pressure that disrupts the alveolar-capillary membrane, leading to patchy, bilateral pulmonary edema.

A 32-Year-Old Man Comes to the Urgent Care Clinic Due