Acute severe and life-threatening asthma — formative SAQs

SAQ 1 (10 marks)

A 7-year-old girl with known asthma is brought to the emergency department. Over the past day her wheeze and breathlessness have worsened despite frequent salbutamol at home. She can speak only in words, has marked subcostal and intercostal recession, a respiratory rate of 40 and heart rate of 150, and her oxygen saturation is 88% on air. She is alert but distressed, with a widespread expiratory wheeze. [1] [5]

1. State your assessment of severity and how you graded it. (3) [1]
2. Outline your initial management, including drugs and route. (4) [2] [3]
3. Describe how you would decide to escalate, and what you would do next. (3) [3]

Model answer — SAQ 1

(1) Severity (3). This is acute severe asthma: she can speak only in words, is hypoxaemic at 88% on air, has marked work of breathing with recession, and is tachypnoeic and tachycardic. I grade severity from the whole child — the ability to talk, the work of breathing, the oxygen saturation, the air entry and the conscious level — rather than any single number, and I would reassess after every intervention because a child can move into the life-threatening band within minutes. [1]

(2) Initial management (4). Sit her up, keep her calm, and give oxygen titrated to keep SpO2 at or above 94%. Start continuous (or back-to-back) nebulised salbutamol and add nebulised ipratropium 250 micrograms for this severe exacerbation, because continuous salbutamol beats intermittent dosing and adding ipratropium reduces admissions in severe disease. Give a systemic corticosteroid early — oral prednisolone 1–2 mg/kg (or IV methylprednisolone/hydrocortisone if not tolerated) — because the benefit takes hours to appear. Call for senior help and secure monitoring. [2] [4]

(3) Escalation (3). I would escalate if she fails to respond to continuous inhaled therapy — persisting hypoxaemia, ongoing marked work of breathing, or any life-threatening feature (silent chest, exhaustion, drowsiness, rising PaCO2). The first intravenous escalation is a single dose of intravenous magnesium sulfate; if she continues to deteriorate I would move to intravenous salbutamol and/or aminophylline in a monitored HDU or PICU setting with cardiac and electrolyte monitoring, involve anaesthetics and PICU early, and prepare for cautious ventilation. [3]

SAQ 2 (10 marks)

A 12-year-old boy with brittle asthma and a previous intensive-care admission presents barely responsive, cyanosed, with minimal air entry and a quiet chest. His oxygen saturation is 84% despite high-flow oxygen, and a blood gas shows a PaCO2 that has risen to the upper normal range. [1] [5]

1. What is your assessment, and which features make it life-threatening? (4) [1]
2. Describe your immediate management priorities. (3) [3]
3. Explain the pitfalls to avoid in this child. (3) [5]

Model answer — SAQ 2

(1) Assessment (4). This is life-threatening, near-fatal asthma. The life-threatening features are the silent chest with minimal air entry (critically reduced ventilation, not calm), cyanosis, a reduced conscious level, and persisting severe hypoxaemia despite high-flow oxygen. The rising PaCO2 into the normal range in a child who is tiring signals a failing respiratory pump and impending respiratory arrest, and his previous ICU admission and brittle asthma mark him as very high risk. [1]

(2) Immediate priorities (3). Treat at the top of the pathway immediately and simultaneously: high-flow oxygen, continuous nebulised salbutamol and ipratropium, a systemic corticosteroid, immediate intravenous access with a single dose of intravenous magnesium sulfate, and intravenous salbutamol and/or aminophylline. Call the airway team, anaesthetics and PICU to the bedside now, and prepare for a controlled intubation by the most experienced operator, ventilating slowly with a long expiratory time and permissive hypercapnia to avoid dynamic hyperinflation. [3]

(3) Pitfalls (3). The dominant pitfalls are misreading the quiet chest and the normalising PaCO2 as improvement rather than danger, delaying escalation to intravenous therapy and critical care in a child who is failing, and underestimating a high-risk child. Intubation itself is hazardous — positive-pressure ventilation can worsen air trapping and cause hypotension or barotrauma — so it must be anticipated and performed carefully rather than as a last-second rescue. [5]