A child with respiratory distress is on high-flow nasal cannula (HFNC) at FiO₂ 50%. Which of the following is the correct step in management?

Correct option is B

HFNC requires heated humidification to prevent mucosal drying, maintain airway clearance, and improve oxygenation. FiO₂ > 50% is avoided long-term to prevent oxygen toxicity.
Explanation of options: (a) ✘ Increasing FiO₂ > 60% risks oxygen toxicity, not first step. (b) ✔ Correct; humidification is mandatory in HFNC therapy. (c) ✘ Invasive ventilation only if HFNC fails. (d) ✘ HFNC without humidification causes mucosal damage.