List some differential diagnoses for respiratory failure.

• A. Asthma/COPD, CHF, pneumonia, respiratory viral illness, acute coronary syndrome, and anaphylaxis.
• B. Common cold, sinusitis, otitis media, bronchitis.
• C. Fracture, sprain, strain, contusion.
• D. Hepatitis, pancreatitis, cholecystitis, gastritis.

Answer: (A)

The main concept here is recognizing a broad differential for acute respiratory failure, covering mechanisms that impair ventilation, gas exchange, or airway patency. The best choice includes representative, high-yield causes across these categories: obstructive airway disease (asthma, COPD) can trigger severe bronchospasm or obstruction; heart failure can lead to pulmonary edema that hampers oxygen transfer; pneumonia and viral respiratory illness cause infection-driven inflammation and alveolar collapse or edema; acute coronary syndrome can worsen oxygen delivery to tissues and precipitate cardiogenic edema; and anaphylaxis produces rapid airway swelling and bronchospasm that sharply reduces airway patency and oxygenation. The other options don’t reflect the common or typical etiologies of respiratory failure—ranging from merely mild upper respiratory infections to non-respiratory injuries or abdominal diseases—so they don’t fit as a focused differential for respiratory failure.