A 2-year-old boy is brought to the emergency department by his parents due to difficulty breathing. The parents report that the child had a runny nose and a mild cough for the past two days. This evening, he woke up with a harsh, barking cough and a high-pitched sound when breathing in. His temperature is 38.2°C (100.8°F), blood pressure is 90/60 mmHg, pulse is 130/min, and respirations are 32/min. On physical examination, the child is awake and alert but appears anxious. He has audible inspiratory stridor while sitting quietly on his mother's lap. There is no drooling, and he is able to swallow water without difficulty. Lung auscultation reveals clear breath sounds bilaterally with referred upper airway noise. There are mild subcostal and intercostal retractions.
Which of the following is the most appropriate next step in the management of this patient?
The correct answer is:
B) Administration of nebulized racemic epinephrine
This patient is presenting with a moderate case of croup, also known as laryngotracheobronchitis. Croup is characterized by a prodrome of upper respiratory infection symptoms followed by the classic barking cough and inspiratory stridor due to subglottic edema. The management of croup depends on the severity of the symptoms. Patients with stridor at rest, as seen in this child, are classified as having moderate to severe croup. The most appropriate next step for a patient with stridor at rest is the administration of nebulized racemic epinephrine. Epinephrine acts as an alpha-1 agonist to constrict the precapillary arterioles in the upper airway mucosa, which rapidly reduces subglottic edema and relieves the airway obstruction. This should be given in conjunction with corticosteroids, such as dexamethasone, to provide a longer-lasting anti-inflammatory effect.
Answer choice A: Administration of intramuscular epinephrine, is incorrect. Intramuscular epinephrine is the first-line treatment for anaphylaxis, which can cause laryngeal edema and stridor. However, anaphylaxis typically presents with an acute trigger, urticaria, and often hypotension or wheezing. In a child with a two-day viral prodrome and a barking cough, croup is the much more likely diagnosis, and nebulized epinephrine is the preferred route for local airway effect.
Answer choice C: Lateral neck radiograph, is incorrect. A lateral neck radiograph is used to look for the thumbprint sign associated with epiglottitis or to evaluate for a retropharyngeal abscess. This patient does not have the high fever, drooling, or muffled voice characteristic of epiglottitis. In croup, the diagnosis is clinical, and imaging is usually not necessary unless the diagnosis is in doubt or the patient fails to respond to standard therapy.
Answer choice D: Oral dexamethasone, is incorrect. Croup is caused by viruses such as parainfluenza virus (most common), respiratory syncytical virus, influenza, or adenovirus. Because of the viral etiology, antibiotics are not part of the management of croup.
Answer choice E: Urgent endotracheal intubation, is incorrect. Intubation is reserved for patients with impending respiratory failure who do not respond to nebulized epinephrine and corticosteroids. Signs of respiratory failure include fatigue, decreased mental status, and worsening hypoxia. This patient is currently alert and has only mild retractions, making medical management the appropriate first step.
Key Learning Point
The management of croup is based on clinical severity. All patients should receive a single dose of corticosteroids, typically dexamethasone. Patients with stridor at rest or significant respiratory distress require the addition of nebulized racemic epinephrine for rapid reduction of subglottic edema.
