high altitude pulmonary edema HAPE

The video clip shows a B-line pattern that is reported to be diffusely distributed throughout all lung fields. Pulmonary edema is the most likely diagnosis, in this case related to high altitude (choice C is correct). Pulmonary edema caused by heart failure would have an identical appearance on ultrasound. B-lines indicate an alveolar interstitial pattern and are nonspecific as to the cause creating this pattern. They may be seen with pulmonary edema, interstitial lung disease, and infection.

The treatment of high-altitude pulmonary edema (HAPE) includes rest, administration of oxygen, and descent to a lower altitude. It carries a 20% mortality and is an emergency. It is usually seen starting at approximately 2,438 m (8,000 feet) but can be seen at any altitude >1,524 m (>5,000 feet). If diagnosed early, recovery is rapid with a descent of only 500 to 1,000 m (3,000 feet). A portable hyperbaric chamber or supplemental oxygen administration immediately increases oxygen saturation and reduces pulmonary artery pressure, heart rate, respiratory rate, and symptoms. In situations where descent is difficult, these treatments can be lifesaving.

At high altitude, systolic pulmonary artery pressure increases less in participants who received dexamethasone (16 mm Hg) and tadalafil (13 mm Hg) than in those who received placebo. Prevention of HAPE is achieved most effectively by gradual ascent, allowing time for proper acclimatization. Certain prophylactic medications may further reduce the risk of ascending to high altitude in individuals with a history of HAPE. Prophylaxis with nifedipine or tadalafil has been studied, but is not frequently used.

The diagnosis of pneumothorax is excluded by the presence of B-lines or sliding lung (choice A is incorrect). A-lines and absence of sliding lung would be found if there were air in the pleural space, such as in a pneumothorax (video). Pulmonary contusion and aspiration pneumonia would both show a consolidation pattern (video) or a scattered B-line morphology intermixed with A lines (choices B and D are incorrect).