Croup severity assessment and dexamethasone

Instructions

You are the ST4 in the paediatric ED at 02:30. Mia Patel is a 2-year-old girl (APLS weight (2+4)×2 = 12kg) brought in overnight by her mum with a 24-hour history of a barking cough, harsh stridor, a hoarse voice and a mild fever. She is awake, alert and sitting upright on mum's lap.

Triage obs: HR 130, RR 35, SpO₂ 96% in air, BP 90/55, temp 38.2°C, BM 5.0, GCS 15. There is a soft stridor audible at rest and mild intercostal recession. Immunisations are up to date per the red book (mum has it with her); ex-term NVD 3.2kg, healthy and thriving on the 50th centile, recently started at a new nursery.

Mum is in the room with Mia on her lap; an actor is playing the mum and the examiner will reveal examination findings on request. You have 8 minutes to assess and manage this child and explain your plan to mum.

Equipment & setting

No equipment notes provided.

Actor / patient brief

Opening line: She started with a runny nose two days ago and then this awful barking cough through the night - she sounds like a seal and I can hear her breathing in from across the room. I'm really scared she's going to stop breathing.

Character: Mia Patel, 2-year-old girl, sat upright on mum's lap, hoarse barking cough every few minutes, soft stridor audible at rest; mum Priya Patel (32, primary carer, first-time mother, works part-time as a teaching assistant).

Hidden concern: Fears Mia will stop breathing in her sleep, has been reading worrying things online about epiglottitis, and is anxious about being judged as an over-anxious first-time mum.

Behaviour: Mum is tired, tearful and protective; visibly reassured when the candidate stays calm and lets Mia remain on her lap. Mia is initially clingy and miserable, settles if not approached too quickly, will allow stethoscope on her chest if mum holds it first; cries and arches if anyone tries to look in her mouth.

Disclose only if asked:

Symptoms started 24h ago: coryza first, then barking cough, hoarse cry and noisy breathing overnight; mild fever, given paracetamol 4h ago.
She is drinking small sips, had half her usual milk, last wet nappy 3h ago; no drooling, no difficulty swallowing, no blue episodes, no tripoding.
Recently started a new nursery 3 weeks ago; older cousin had a cold last weekend; no foreign body witnessed, no choking episode.
Ex-term NVD at 39+4, birth weight 3.2kg, no neonatal complications, breastfed until 12 months, now eats and grows well, on 50th centile (red book carried).
Immunisations fully up to date including Hib and MenB per red book; no PMH, no admissions, no medications, no allergies.
Developmental milestones normal: walking from 13 months, 30+ words, follows two-step commands, plays alongside other children.
Lives with mum, dad and maternal grandmother; non-smoking household, no pets; no safeguarding concerns; dad is a delivery driver, currently at work.
ICE: worried it could be 'something serious like meningitis' or that 'her airway will close'; really doesn't want her admitted overnight if avoidable; off work tomorrow so can stay with her.

Finish your timed attempt before revealing the answer.

The tasks & expected progression

Take a focused croup history including red flags for epiglottitis, bacterial tracheitis and foreign body.
Perform a focused paediatric ENT and respiratory exam without distressing the child.
Grade severity using the Westley Croup Score and justify your category.
Prescribe dexamethasone at the correct BNFc dose for 12kg with an alternative if vomiting.
Counsel mum on natural history, red flags and a written safety net before discharge.

0-1 min Open & focused history Greet mum and Mia, do not separate; clarify onset (24h), barking cough, stridor at rest now vs only with crying, hoarseness, fever 38.2°C; nursery exposures; feeding, wet nappies, drooling, posture, lethargy; immunisations (Hib), PMH, allergies; ICE.
1-3 min Focused paediatric examination Examine on mum's lap: general appearance, work of breathing, recession, tracheal tug, stridor at rest, air entry, sats, perfusion, no drooling, no tripoding, no toxic look. Avoid throat exam and tongue depressor. Examiner reveals findings: soft stridor at rest, mild intercostal recession, clear chest, no cyanosis.
3-5 min Investigations & formulation Croup is clinical — no routine bloods, no neck XR, no throat exam. Calculate Westley: stridor at rest 1 + mild recession 1 + air entry normal 0 + no cyanosis 0 + alert 0 = 3 (moderate). Differential: epiglottitis (toxic, drooling, tripod), bacterial tracheitis, inhaled foreign body, retropharyngeal abscess, anaphylaxis.
5-7 min Management & parent communication Keep calm on mum's lap, minimal handling. Dexamethasone 0.15mg/kg PO STAT = 1.8mg PO (BNFc/RCPCH; max typically 10mg). If vomits, nebulised budesonide 2mg or prednisolone 1mg/kg PO. Reserve nebulised adrenaline 1:1000 0.5mL/kg (max 5mL) for severe (Westley ≥8) with PICU/anaesthetic alert and 2-4h observation for rebound.
7-8 min Safety net & follow-up Observe 2-4h post-steroid; discharge if stridor settled or only on exertion, sats normal, feeding, alert, parents confident, can re-attend. Written safety net: return if stridor at rest worsens, blue/grey colour, drooling, can't talk/swallow, lethargy, working hard to breathe. No antibiotics (viral); paracetamol/ibuprofen for comfort; usually resolves 3-7 days, worse at night.

Mark scheme

Clinical assessment

40%

Excellent Calm child-led history on mum's lap; covers onset, barking cough, stridor at rest vs exertion, drooling, posture, hydration, immunisations including Hib, nursery contacts, PMH and ICE; focused exam without distress; correctly elicits stridor at rest, mild recession, clear chest, no cyanosis; explicitly avoids throat exam.
Above standard Structured paediatric history covering croup symptoms, immunisations, feeding, exposures and ICE; calm focused exam on mum's lap; gathers stridor at rest, recession and saturations; avoids throat exam and tongue depressor; minor omissions in nursery or birth history.
Standard Takes a coherent croup history and notes stridor, cough and fever; performs a focused respiratory exam without obviously upsetting Mia; identifies stridor at rest and recession; avoids throat exam; some paeds-specific elements (immunisations, feeding, development) lightly covered.
Borderline History covers main respiratory symptoms but misses immunisation status, red flags or ICE; exam is partially completed, may briefly upset the child; identifies stridor but not whether at rest or on exertion; does not explicitly avoid throat exam; vitals not interpreted for age.
Below standard Disorganised history with several paediatric-specific omissions (immunisations, feeding, exposures); exam distresses Mia or is incomplete; fails to characterise stridor; misinterprets HR/RR using adult ranges; misses recession or saturations.
Unacceptable Examines the throat with a tongue depressor, separates Mia from mum, or fails to take any structured paediatric history; misses obvious stridor at rest and recession; ignores immunisation status and safeguarding screen entirely; unsafe approach to a frightened toddler.

Clinical reasoning

30%

Excellent Calculates Westley score correctly (~3, moderate) and justifies; recognises croup is clinical, no routine investigations or neck XR; gives dexamethasone 0.15mg/kg PO = 1.8mg with BNFc-grade alternative (budesonide neb 2mg or prednisolone 1mg/kg); plans 2-4h observation; clear escalation criteria for nebulised adrenaline and PICU/anaesthetic alert; broad differential covered.
Above standard Applies Westley score and grades moderate; correct dex dose with sensible alternative; observes post-steroid; identifies escalation triggers and adrenaline indication; differential includes epiglottitis, bacterial tracheitis and foreign body; minor gaps in observation period or rebound counselling.
Standard Identifies moderate croup and prescribes dexamethasone at correct dose; aware nebulised adrenaline is for severe disease; gives sensible disposition; differential mentioned but not fully explored; framework reference (RCPCH/BNFc) present but limited.
Borderline Identifies croup and gives dexamethasone but at wrong dose or without weight-based calculation; does not formally grade severity; vague about when to escalate to adrenaline; limited differential; no clear plan for observation or rebound risk.
Below standard Misclassifies severity, omits or markedly mis-doses dexamethasone, or requests inappropriate investigations (routine bloods, neck XR, throat swab); fails to consider epiglottitis or foreign body; gives nebulised adrenaline without indication or doesn't know dose.
Unacceptable Gives adult steroid dose, no steroid at all, or antibiotics as primary treatment; misses obvious red flags such as drooling or toxic appearance; fails to plan for airway escalation; unsafe disposition (e.g., immediate discharge without observation or with worsening stridor).

Communication

30%

Excellent Warm, child-friendly approach; introduces self to mum and Mia; explains croup is a viral illness, worse at night, usually settles in 3-7 days; explains role of dexamethasone and that antibiotics are not needed; gives a clear verbal and written safety net (stridor at rest worsening, blue/grey colour, drooling, can't swallow, lethargy); checks understanding and addresses parental ICE.
Above standard Explains diagnosis, natural history and treatment in plain English; covers most safety net points; reassures appropriately without dismissing concern; offers written information and follow-up route; minor omissions in checking understanding or addressing hidden concern about admission/work.
Standard Conveys diagnosis and management understandably; gives a basic safety net and antipyretic advice; mentions no antibiotics needed; some paediatric communication elements (sitting at child's level, allowing Mia to stay on mum's lap) present; ICE partly addressed.
Borderline Explanation is medicalised or rushed; safety net is generic and lacks specific red flags for croup; does not explicitly address mum's concerns; written information not offered; check of understanding absent or perfunctory.
Below standard Communication is one-way and uses jargon; ignores mum's anxiety; fails to give a meaningful safety net; recommends unevidenced measures (steam, cold air as treatment) without caveat; does not signpost when to re-attend.
Unacceptable Dismissive or alarming language; gives incorrect advice (e.g., antibiotics will fix it, no need to return); fails to safety net at all; ignores or talks over the parent; no acknowledgement of Mia as a person or of mum's ICE.

— Self-mark each domain

Weighted across all domains · Day-1 consultant standard · pass mark 60%.

What good looks like

Westley Croup Score (0-17): LOC 0/5, cyanosis 0/4/5, stridor 0/1/2, air entry 0/1/2, retraction 0/1/2/3. Mild ≤2, Moderate 3-7, Severe 8-11, Impending respiratory failure ≥12 (RCPCH).
Dexamethasone 0.15mg/kg PO STAT works within 30min and lasts 12-24h (BNFc/RCPCH). Give to ALL severities including mild croup; for 12kg = 1.8mg PO. Typical maximum 10mg.
If vomiting or won't take oral dex, use nebulised budesonide 2mg one-off or prednisolone 1mg/kg PO. All three are evidence-based alternatives per RCPCH croup guidance.
Nebulised adrenaline 1:1000 0.5mL/kg (max 5mL) is reserved for severe croup; effect peaks 30min and wears off <2h, so observe 2-4h for rebound and alert PICU/anaesthetics early.

Common pitfalls

Examining the throat or using a tongue depressor in suspected epiglottitis or severe croup — can precipitate complete obstruction. Inspect from a distance with the child calm on the parent's lap.
Using adult vital ranges; for a 1-2y child normal HR is 100-150, RR 25-35, SBP 80-95 (APLS) — HR 130 and RR 35 here are appropriate, not tachycardic-for-age.
Withholding steroids in 'mild' croup — RCPCH and Cochrane evidence support dexamethasone in ALL severities, reducing return visits and admissions.
Missing red flags for epiglottitis (toxic, drooling, tripoding, muffled voice, no cough, unvaccinated for Hib) or bacterial tracheitis (toxic, thick secretions, poor response to adrenaline) by anchoring on viral croup.