Final answer:
The highest priority action by the nurse would be to assess the child's airway and breathing, potentially administer humidified oxygen, and prepare for medication administration to ease symptoms and ensure the child's airway remains open.
Step-by-step explanation:
The question pertains to a 2-year-old child presenting with inspiratory stridor and a barking cough. The highest priority action by the nurse in this case would be to assess the child's airway and breathing to ensure they are stable. Given these symptoms, one possible diagnosis could be croup, which is common in young children and can cause a swollen airway and difficulty breathing. The nurse may need to administer humidified oxygen, and in severe cases, medications such as corticosteroids or nebulized epinephrine may be necessary to reduce airway inflammation. It is crucial to act quickly and calmly to manage the child's symptoms and prevent respiratory distress.