Childhood Asthma OSCE - Acute Asthma Attack

Case Overview

• Age/Sex: 11-year-old male
• Occupation: Primary school student (Grade 6)
• Setting: Emergency Department with parent as historian
• Chief complaint: "He's wheezing and coughing — can't catch his breath"

Patient Script

Who I Am

I'm his mum — he's an 11-year-old boy in Year 6 and I'm here because he's having trouble breathing.

What Brings Me In

He's been wheezy and coughing a lot and now he's struggling to talk and looks very breathless.

My Story

He started with a runny nose and a cough about 3 days ago after being at school. This evening, about 2 hours ago, he suddenly got much worse — a lot of coughing and loud wheeze, and now he can only speak in short phrases. He's been breathing fast and pulling in at his ribs; he looks frightened and has been sitting upright. I gave him his blue inhaler (salbutamol) with a spacer once when it started getting bad, but it didn't seem to help much. He had an asthma flare last year but hasn't been in hospital for it in over a year. He has been forgetting to use his preventer inhaler recently because school has been busy.

I noticed he swallowed a couple of peanuts at a party this afternoon, but he didn't break out in a rash and his face didn't swell. Yesterday he had a little fever at home (about 38.2°C) for a short while, which we treated with ibuprofen. He was well enough to go to school earlier today and he did PE this morning; after PE he had a bit of a cough but was fine until this evening.

My Medical Background

• Past medical history: intermittent asthma diagnosed at age 4; one hospital admission for asthma 2 years ago
• Medications: salbutamol inhaler (blue) PRN; has beclomethasone inhaler (brown) but uses it only occasionally
• Allergies: none known (no reaction to peanuts earlier today)
• Social: lives with parents and a younger sister; parent occasionally smokes outside the house
• Family: mother with hay fever; no family history of cystic fibrosis or congenital heart disease

What I Think & Worry About

• I think this is his asthma getting really bad again.
• I'm worried he might stop breathing or need to go to intensive care.
• I want him to get better quickly and for you to tell me what to do at home so this doesn't happen again.

If You Ask Me About Other Symptoms...

• Fever: "He had a bit of a fever yesterday, but not now — maybe 37.8°C at home."
• Rash/Swelling: "No rash, no facial swelling after the peanuts."
• Vomiting/Abdominal pain: "He threw up a little from coughing earlier, but no tummy pain."
• Recent infections: "He had a cold for a couple of days before this got bad."
• Exercise: "He was doing PE at school this morning, seemed fine then."
• Medication use: "I gave one puff of the blue inhaler with a spacer when he got worse; I haven't given steroids today."
• Smoking exposure: "I smoke sometimes but I go outside — sometimes there is smoke smell when he comes in."

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Clinical Summary

Examination

• General: tired, anxious 11-year-old boy sitting upright on parent's lap, speaking in short phrases
• Respiratory rate: 36 breaths/min (tachypnoea)
• Heart rate: 128 bpm (tachycardia)
• Blood pressure: 105/65 mmHg
• Temperature: 37.8°C
• Oxygen saturation: 88% on room air (improves with oxygen)
• Chest: marked intercostal and suprasternal recession; accessory muscle use; diffuse expiratory wheeze audible without stethoscope and bilateral wheeze on auscultation; reduced air entry at both bases
• Ability to speak: sentences broken into short phrases/words
• Peak expiratory flow: ~120 L/min (predicted for age/height ~350–400 L/min) — significant reduction
• Neurology/other: alert but fatigued; no stridor, no urticaria, no angioedema

Investigations

• SpO2 on room air: 88% (hypoxaemia)
• SpO2 on high-flow oxygen (humidified): 94% (response to oxygen)
• Arterial/capillary blood gas: pH 7.33, pCO2 52 mmHg, pO2 6.4 kPa (48 mmHg) on room air (hypercapnia and hypoxaemia — concerning)
• Peak expiratory flow: 120 L/min (severe obstruction)
• Chest X-ray: hyperinflation, no focal lobar consolidation, no pneumothorax (to exclude other complications)
• Viral PCR (nasal swab): rhinovirus positive (possible trigger)
• CBC: WCC mildly elevated 12 x10^9/L (consistent with viral/viral-triggered inflammation)

Diagnosis

Primary diagnosis:

• Acute severe asthma exacerbation (status: severe) — supported by history of known asthma, progressive dyspnoea over 2 hours, accessory muscle use, inability to speak in full sentences, marked wheeze, low oxygen saturation, severely reduced peak flow, and hypercapnia on blood gas.

Differential diagnoses:

• Anaphylaxis — less likely: no hypotension, no urticaria/angioedema, no airway angioedema despite peanut exposure.
• Foreign body airway obstruction — less likely: bilateral wheeze and gradual progression over days with prodrome (viral symptoms) rather than sudden focal findings or unilateral decreased air entry.
• Pneumonia with bronchospasm — less likely: temperature only low-grade, CXR without focal consolidation, viral PCR positive suggesting viral-induced asthma exacerbation.
• Vocal cord dysfunction/psychogenic hyperventilation — less likely: objective hypoxaemia and wheeze on auscultation point to lower-airway obstruction.

Management

• Immediate:

  • Ensure airway patency and rapid assessment of circulation and breathing (ABCDE).
  • Administer high-flow oxygen to maintain SpO2 ≥ 92% in children (titrate to 94% where possible).
  • Nebulized salbutamol (short-acting beta-agonist): continuous or repeated doses (e.g., 2.5–5 mg via nebulizer for child, repeated/continuous as per local paediatric protocol) with oxygen-driven nebulization.
  • Add inhaled ipratropium bromide (anticholinergic) nebulization in the first hour (e.g., 250 mcg) for severe exacerbation.
  • Give systemic corticosteroid promptly (oral prednisolone 1–2 mg/kg up to 40 mg or IV equivalent if vomiting or severe) — do not delay for imaging/tests.
  • Monitor response: respiratory rate, work of breathing, oxygenation, heart rate, peak flow, and level of consciousness.
  • Arrange for continuous observation in ED with paediatric/respiratory team involvement and prepare for escalation.

• If poor response or signs of respiratory muscle fatigue/ventilatory failure (rising CO2, decreasing consciousness):

  • Consider intravenous magnesium sulfate (single dose 25–50 mg/kg up to 2 g) as bronchodilator adjunct.
  • Prepare for non-invasive ventilation if available and appropriate, and have paediatric anesthetic/intensive care team ready for intubation and mechanical ventilation if needed.

• Other practical steps:

  • Avoid sedatives and high-volume IV fluids that might worsen respiratory status.
  • Reassure parent, explain immediate steps and likely need for observation/admission.
  • Review inhaler technique and adherence to preventer therapy before discharge planning.
  • Provide or update written asthma action plan and arrange follow-up with primary care/pediatric respiratory clinic on discharge.

Key Learning Points

• Recognize life-threatening/acute severe asthma by clinical signs: accessory muscle use, inability to speak in sentences, poor air entry, hypoxaemia (SpO2 < 92%), and rising CO2 as an ominous sign of respiratory fatigue.

• Initial management priorities are rapid assessment (ABCDE), oxygen to correct hypoxaemia, prompt nebulized bronchodilator therapy (salbutamol ± ipratropium), and early systemic corticosteroids — do not delay steroids while awaiting investigations.

• Always consider differential diagnoses (anaphylaxis, foreign body, pneumonia) and be prepared to escalate to pediatric ICU support (magnesium, ventilatory support) if the child fails to improve or shows signs of impending respiratory failure.