A 9-month-old child presented to the ER with characteristic "barking" cough and hoarseness of voice. She had a history of rhinorrhoea, pharyngitis, mild cough, and low-grade fever for 1-3 days. Symptom worsened at night. O/E: - Normal to moderately inflamed pharynx Increased respiratory rate Nasal flaring Suprasternal, infrasternal, and intercostal retractions Continuous inspiratory stridor X-RAY NECK All of the following statements are true about the treatment of the above condition except: -