Upper-airway obstruction and stridor — formative SAQs

SAQ 1 — The toddler with a barking cough (20 marks, ~15 minutes)

A previously well 2-year-old is brought to the emergency department at 2 am with a two-day coryzal prodrome and a sudden onset overnight of a barking, seal-like cough, a hoarse voice and inspiratory stridor that is worse when he cries. He is alert, pink, afebrile, drinking, and has mild intercostal recession with good air entry. Oxygen saturations are 98 percent in air. ^[1]

Questions

1. Give the most likely diagnosis and the typical causative organism, and state the two features that make a toxic airway emergency unlikely. (4 marks) ^[1]
2. Grade this child's severity, naming the score and its components. (4 marks) ^[1]
3. State your management for this child, with the specific drug and dose, and your management if he deteriorated to severe obstruction. (6 marks) ^[3]
4. State the evidence that supports treating even mild croup. (3 marks) ^[2]
5. State your disposition and the safety-netting advice you would give the family. (3 marks) ^[1]

Model answer (must-hit)

1. The most likely diagnosis is croup (laryngotracheobronchitis), most commonly caused by a parainfluenza virus. A toxic airway emergency such as epiglottitis is made unlikely by the absence of toxicity and drooling and by the child's ability to drink and to lie comfortably, together with the presence of the characteristic barking cough and hoarse voice, which are features of croup rather than supraglottic disease. ^[1]
2. Severity is graded with the Westley croup score, which uses five components: level of consciousness, cyanosis, air entry, stridor and retractions. This child has stridor only when upset, good air entry, no cyanosis, normal consciousness and mild retractions, giving a score below 3 — mild croup. ^[1]
3. Management of mild croup is a single dose of oral dexamethasone 0.15 to 0.6 mg/kg (commonly 0.15 mg/kg), keeping the child calm and undistressed, with observation until settled. If he deteriorated to severe obstruction (marked stridor at rest, reducing air entry, distress), I would give nebulised adrenaline 0.5 mL/kg of 1:1000 (maximum 5 mL) for rapid temporary relief, provide oxygen, involve senior and anaesthetic help, and observe for rebound as the adrenaline wears off at about two hours. ^{[3] [4]}
4. The randomised controlled trial of dexamethasone for mild croup and the Cochrane review of glucocorticoids for croup showed that corticosteroid reduces symptom severity and duration, return visits and the need for adrenaline and admission across all severities, including mild disease, which is why dexamethasone is given to essentially all children with croup. ^{[2] [3]}
5. A child with mild croup who is comfortable after dexamethasone can be discharged with clear safety-netting: croup fluctuates and is often worse at night; return if there is stridor at rest, increasing work of breathing, drowsiness, pallor or difficulty drinking. Keep the child calm at home. ^[1]