Croup — branching viva

Opening

Examiner: A 2-year-old arrives at 1 a.m. with a barking cough, a hoarse cry and inspiratory stridor at rest after two days of a runny nose. He is alert and pink on his mother's lap. How do you approach him? [1]

Candidate: I would make a clinical diagnosis of viral croup and grade its severity by observation before touching him, keeping him calm on his mother's lap because agitation worsens the obstruction. He has stridor at rest, so this is at least moderate croup on the Westley score; I would note his retractions, air entry, colour and conscious level. My immediate plan is a corticosteroid for him as for every child with croup, calm handling, and nebulised adrenaline ready if he develops distress, with observation and reassessment. [1] [2]

Branch 1 — grading and steroid

Examiner: Why give a steroid if he might only be moderate? [2]

Candidate: Because the evidence supports a corticosteroid for every child with croup across the whole severity range. The Cochrane review of glucocorticoids for croup shows they reduce symptom severity, return visits, length of stay and the need for adrenaline, and the Bjornson NEJM trial showed benefit even in mild croup. I would give dexamethasone 0.15 mg/kg orally as a single dose, or nebulised budesonide 2 mg if he will not take it orally. [2] [4]

Examiner (probe): What score is the Westley score made of? [1]

Candidate: Five items: inspiratory stridor, chest-wall retractions, air entry, cyanosis, and level of consciousness. I use the total to place him from mild through moderate and severe to impending failure, but I rely more on serial scores to read the trajectory than on any single number. [1]

Branch 2 — the deteriorating child

Examiner: An hour later the nurse says he has gone quiet and is easier to settle. Reassured? [1]

Candidate: Not automatically — I would go and look. A child who becomes quiet, still, pale or drowsy with a falling respiratory rate may be tiring, not improving: reduced noise can mean reduced air movement through a critically narrowed airway. A silent chest with poor air entry in a previously stridulous child is a pre-arrest sign. I would reassess him fully, and if he is deteriorating I would give nebulised adrenaline and call for senior, anaesthetic and ENT help. [1]

Examiner (probe): Give me your adrenaline dose and what you expect from it. [3]

Candidate: Nebulised adrenaline 1:1000 (1 mg/mL), 0.5 mL/kg to a maximum of 5 mL, or racemic adrenaline where available. It works within minutes by vasoconstricting the oedematous mucosa, but its effect wanes over about two hours, so I must observe him for rebound and not discharge him on the strength of a good initial response. The Cochrane review confirms a real but transient benefit that mandates observation. [3] [2]

Branch 3 — the mimic

Examiner: A different 3-year-old is toxic, febrile, drooling, sitting forward, with a muffled voice and no barking cough. Same approach? [5]

Candidate: No. That picture is epiglottitis until proven otherwise, not viral croup. I would not examine her throat, cannulate her or lie her flat, because that can precipitate complete obstruction. I would keep her calm with her parent, give gentle oxygen if tolerated, and call the airway team — senior paediatrician, anaesthetics and ENT — for a controlled airway assessment, with intravenous antibiotics once the airway is secured. I would also keep bacterial tracheitis, a foreign body and, if immunisation is incomplete, membranous croup in mind. [5] [1]

Examiner (probe): Would neck X-rays help you decide? [1]

Candidate: No. Croup is a clinical diagnosis and imaging is not routine; the steeple sign is neither necessary nor sufficient, and obtaining films risks distressing and delaying a child with a compromised airway. Imaging belongs to the workup of an atypical presentation, not to routine croup or to a child I suspect has epiglottitis. [1]

Close

Examiner: Summarise your safe approach to croup in one line. [2]

Candidate: Grade the severity from across the room, give a steroid to every child, rescue the severe with nebulised adrenaline and observe them for the two-hour wane, keep the child calm, and stay alert for the toxic or atypical child who has a dangerous mimic rather than croup. [2] [5]