HFNC is indicated to reduce risk of post-extubation hypoxemic respiratory failure. Which option is correct about this indication?

• A. Hypercapnic respiratory failure risk
• B. Hypoxemic respiratory failure risk
• C. Pulmonary embolism
• D. Seizure

Answer: (B)

HFNC after extubation is used to prevent hypoxemia by improving oxygenation. It delivers heated, humidified oxygen at high flow with a precisely adjustable FiO2 and creates a small amount of positive airway pressure. This helps keep alveoli open, reduces inspiratory work, and washes out nasopharyngeal dead space, all of which support better oxygenation in the immediate post-extubation period. That makes the focus of the indication specifically on reducing the risk of hypoxemic respiratory failure after extubation. Hypercapnic respiratory failure, pulmonary embolism, and seizures are not addressed by this oxygenation-focused strategy, whereas hypercapnia is typically managed with different ventilatory support unless indicated otherwise.