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Acute hypercapnic respiratory failure in COPD — SCE Respiratory MCQ

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ModerateCOPDAcute hypercapnic respiratory failure in COPDSCE Respiratory

A 72-year-old woman with severe COPD arrives with increasing sputum purulence and confusion. RR is 30/min, SpO2 is 86% on air, BP 138/74 mmHg and temperature 37.7°C. After controlled oxygen at 28%, ABG shows pH 7.27, PaCO2 9.2 kPa, PaO2 8.1 kPa and HCO3- 31 mmol/L. What is the most appropriate ventilation strategy?

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Correct answer: C — Start NIV with oxygen titrated to SpO2 88-92%

This is acute-on-chronic hypercapnic respiratory failure with respiratory acidaemia during a COPD exacerbation, so NIV with controlled oxygen is indicated. CPAP improves oxygenation but does not provide the same ventilatory assistance for CO2 clearance, and uncontrolled high-flow oxygen can worsen hypercapnia. Intubation is considered if NIV fails or contraindications emerge; the initial specialist step here is prompt NIV.

Reference: BTS/ICS AHRF Guideline; NICE NG115; BTS Oxygen Guideline