Respiratory emergencies
COPD exacerbation
Overview and approach
An exacerbation is worsening respiratory symptoms; exclude pneumonia, PE, pneumothorax and cardiac failure.
- COPD-X defines an exacerbation as a change in baseline dyspnoea, cough and/or sputum beyond normal day-to-day variation, acute in onset, that may warrant a change in regular medication or admission. Early diagnosis and treatment may prevent admission and slow progression (1).
- Exacerbations become more frequent as COPD worsens. The best predictor of future exacerbations is a history of previous exacerbations. 12-month mortality is about 15% after hospitalisation versus 5% without (1).
Assessment and clinical features
Work of breathing, cognition, saturation, sputum, haemodynamics and baseline CO2/oxygen history.
- Increased breathlessness, cough, sputum volume or purulence, and fever. Sputum purulence and fever are the features that support antibiotics (1).
- Check baseline oxygen/CO2 history, home oxygen, previous NIV and the action plan.
- Severity scoring: DECAF is a 30-day mortality score (extended MRC dyspnoea, eosinopenia, consolidation, acidaemia, atrial fibrillation) (1).
Differentials and investigations
Blood gas when hypercapnia or severe illness is possible; chest imaging and targeted infection testing.
- Other causes or mimics: left ventricular failure and pulmonary embolism. A systematic review found 16% of admitted COPD exacerbations undergoing CTPA had PE (range 3-29%) (1).
- Usual organisms colonising the airway: Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis; the role of bacterial infection is debated (1).
- Arterial or venous blood gas for hypercapnia and acidaemia; chest X-ray; ECG.
Management and follow-up
Controlled oxygen, bronchodilators, selected steroids/antibiotics and ventilatory support under local COPD-X-based pathway.
- Bronchodilators: inhaled short-acting bronchodilators first line (1).
- Steroids: oral prednisolone 30-50 mg daily for 5 days (1).
- Antibiotics: amoxicillin or doxycycline for 5 days if features of infection (more or purulent sputum, fever) (1).
- Oxygen: for hypoxaemia, target SpO2 88-92% using controlled delivery (0.5-2 L/min). It improves survival (1).
- Non-invasive ventilation improves survival in acute hypercapnic respiratory failure (1).
- Recovery: refer to pulmonary rehabilitation (reduces readmissions), arrange comprehensive follow-up in primary care, use discharge bundles and review the action plan and inhaler technique (1).
Red flags and clinical pearls
In hypoxaemic COPD exacerbations commonly target SpO2 88–92% with blood-gas reassessment. Acute hypercapnic respiratory failure may benefit from NIV; deterioration needs urgent escalation.
- Readmission risk is highest in the first 3 months after discharge (1).
- Always repeat the blood gas after changing oxygen; rising CO2 or falling pH means escalation.
- Consider PE if the exacerbation has no clear trigger or does not respond to treatment (1).
Last updated from Sen’s notes on 9 October 2026.