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Life-threatening acute asthma — SCE Respiratory MCQ

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HardAsthmaLife-threatening acute asthmaSCE Respiratory

A patient with acute asthma remains unable to speak, has PEFR 28% of best and PaCO2 5.9 kPa after intensive bronchodilator treatment. What is the correct interpretation?

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Correct answer: CRecognise impending ventilatory failure

Acute asthma should produce hypocapnia. A normal or raised PaCO2 in a distressed patient indicates failing ventilation and impending respiratory arrest, especially with exhaustion, silent chest or altered consciousness. The original keyed discharge advice was dangerously wrong; urgent anaesthetic and critical-care involvement is required.

Reference: NICE NG245: Asthma diagnosis, monitoring and chronic management. https://www.nice.org.uk/guidance/ng245/chapter/recommendations; BTS Guideline for Oxygen Use in Adults. https://www.brit-thoracic.org.uk/quality-improvement/guidelines/emergency-oxygen/