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Obesity hypoventilation syndrome with acute ventilatory failure — SCE Acute Medicine MCQ

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HardRespiratory medicineObesity hypoventilation syndrome with acute ventilatory failureSCE Acute Medicine

A 54-year-old man with BMI 52 kg/m2 is admitted with morning headaches, somnolence and ankle swelling after a viral illness. ABG on air shows pH 7.31, PaCO2 8.7 kPa, PaO2 7.4 kPa and bicarbonate 36 mmol/L. Chest radiograph shows low lung volumes without consolidation, and spirometry from last year showed no airflow obstruction. What is the most appropriate next step in management?

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Correct answer: B — Start non-invasive ventilation and controlled oxygen

Obesity hypoventilation syndrome can present with acute-on-chronic hypercapnic respiratory failure, and NIV is appropriate when there is acidaemia. High-flow oxygen without ventilatory support can worsen CO2 retention. Outpatient sleep assessment is important later, but acute ventilatory failure requires treatment now.

Reference: https://cks.nice.org.uk/#acute-medicine-order-83-1