How do HAPE and HACE typically differ in presentation?

• A. HAPE: tachycardia with dry cough; HACE: euphoria.
• B. HAPE: confusion and ataxia; HACE: dyspnea at rest.
• C. HAPE: dyspnea at rest with crackles and hypoxemia; HACE: confusion, ataxia, decreased mental status.
• D. HAPE: fever; HACE: rash.

Answer: (C)

HAPE and HACE present in different organ systems, so the key idea is matching respiratory signs to HAPE and neurological signs to HACE. HAPE is a pulmonary problem from edema in the lungs, so you look for breathing difficulties that are present at rest, with abnormal lung sounds (crackles) and low blood oxygen. HACE is a brain edema problem, so the telltale signs are neurological: confusion, impaired coordination (ataxia), and a decreased level of mental status.

The best description pairs these correctly: dyspnea at rest with crackles and hypoxemia for HAPE, and confusion, ataxia, and decreased mental status for HACE. Other options mix in symptoms that aren’t typical for these conditions—fever, rash, euphoria, or presenting symptoms that don’t fit the pulmonary versus cerebral pattern.