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COPD: Diagnosis and Exacerbations — MCCQE Notes

Post-bronchodilator spirometry makes the diagnosis, and only three interventions change mortality.

MCCQERespiratory5 min read

Diagnosis

Post-bronchodilator FEV₁/FVC < 0.70 in a patient with the right exposure and symptoms. Without spirometry there is no diagnosis — this is a frequent exam point, since many stems describe a smoker labelled COPD who has never had a test.

Consider alpha-1 antitrypsin deficiency when COPD appears before 45, in a non-smoker, with a basal-predominant emphysema distribution, or with unexplained liver disease.

What actually changes mortality

Only three things:

  1. Smoking cessation — the single most effective intervention at any stage
  2. Long-term oxygen therapy, ≥ 15 hours a day, for resting PaO₂ ≤ 55 mmHg (or ≤ 59 with cor pulmonale or polycythaemia)
  3. Lung volume reduction surgery in carefully selected upper-lobe emphysema with poor exercise capacity

Everything else — bronchodilators, pulmonary rehabilitation, vaccination — improves symptoms, exacerbations or quality of life. Pulmonary rehabilitation has the largest effect on breathlessness and should be offered far more often than it is.

Maintenance inhalers

Driven by symptoms and exacerbation history rather than FEV₁ alone:

  • Breathless, few exacerbations → LAMA or LABA, then LAMA–LABA
  • Frequent exacerbations → LAMA–LABA, adding an ICS where the blood eosinophil count is raised or there is an asthma overlap
  • Inhaled corticosteroids in COPD increase pneumonia risk, so the eosinophil count is doing real work in that decision

Acute exacerbation

Increased dyspnoea, sputum volume or sputum purulence.

  • Controlled oxygen to a target of 88–92%. Uncontrolled high-flow oxygen causes CO₂ retention and is a favourite wrong answer
  • Short-acting bronchodilators, salbutamol with ipratropium
  • Systemic corticosteroids — prednisone 40 mg for 5 days
  • Antibiotics when at least two of the three cardinal symptoms are present (purulence must be one), or if ventilation is needed
  • Non-invasive ventilation for respiratory acidosis with pH < 7.35 and hypercapnia — it reduces intubation and mortality, and delaying it is the common error

Palliative and end-of-life

Severe COPD has a prognosis comparable to many cancers. Advance care planning, opioids for refractory breathlessness, and early palliative involvement are appropriate answers, not defeatist ones.

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