What is the likely diagnosis and treatment for a smoker experiencing shortness of breath and wheezes?

Likely Diagnosis: Chronic Obstructive Pulmonary Disease (COPD)

This smoker presenting with shortness of breath and wheezes most likely has COPD, which must be confirmed with spirometry showing post-bronchodilator FEV1/FVC <0.70. 1

Diagnostic Approach

Clinical Suspicion

• Patients over 50 years with long-term smoking history and chronic breathlessness on minor exertion should be treated as having suspected COPD. 2
• The constellation of wheezing, shortness of breath, and smoking history are cardinal features pointing to COPD. 3
• A smoking history of more than 40 pack-years significantly increases the likelihood of COPD. 4

Essential Diagnostic Testing

• Spirometry is mandatory to confirm COPD diagnosis—a post-bronchodilator FEV1/FVC ratio ≤0.7 confirms airflow limitation that is not fully reversible. 1
• Physical examination findings like wheezing during tidal breathing, prolonged forced expiratory time (>5 seconds), and use of accessory respiratory muscles support the diagnosis, but physical signs alone are poor guides to severity and cannot exclude COPD. 2
• Chest radiography helps with differential diagnosis but may be normal in mild-to-moderate COPD. 1, 3

Key History Elements to Document

• Detailed smoking history in pack-years (calculated as packs per day × years smoked). 3, 5
• Occupational and environmental exposures to noxious particles or gases. 1, 3
• Pattern of dyspnea (at rest vs. with exertion), presence of chronic cough, sputum production (especially if purulent), and frequency of respiratory infections. 1

Initial Management Strategy

Smoking Cessation (Highest Priority)

• Provide clear explanation of smoking's effects and strongly encourage abrupt cessation rather than gradual reduction. 2
• Offer nicotine replacement therapy (gum or transdermal patches) combined with behavioral intervention, which increases success rates. 2, 5
• Approximately one-third of patients successfully quit with support; multiple attempts are typically needed. 2

Pharmacological Treatment

• Start with inhaled bronchodilator therapy to relieve symptoms, choosing from β2-agonists, anticholinergic drugs (such as tiotropium), or methylxanthines. 2
• For stable COPD, initiate monotherapy with either a long-acting beta2-agonist (LABA) or long-acting muscarinic antagonist (LAMA). 6
• If dyspnea persists with single bronchodilator, escalate to dual therapy with LABA plus LAMA. 6
• Inhaled corticosteroids should be added only for patients with continued exacerbations despite LABA-LAMA therapy. 6

If Acute Exacerbation is Present

• If purulent sputum is present, prescribe antibiotics for 7-14 days (amoxicillin, tetracycline derivatives, or amoxicillin/clavulanic acid). 2
• Consider systemic corticosteroids for moderate exacerbations to improve lung function and shorten recovery time. 3
• Short-acting beta2-agonists with or without short-acting muscarinic antagonists are basic therapy for acute exacerbations. 6

Severity Classification After Spirometry

Once spirometry confirms diagnosis, classify severity using post-bronchodilator FEV1 1:

• Mild COPD: FEV1 ≥80% predicted (FEV1/FVC ≤0.7)
• Moderate COPD: FEV1 50-80% predicted
• Severe COPD: FEV1 30-50% predicted
• Very severe COPD: FEV1 <30% predicted

Critical Pitfalls to Avoid

• Do not rely on absence of wheezing or physical signs to exclude COPD—spirometry is essential. 2
• Normal chest X-ray does not exclude COPD or its exacerbations. 3
• Do not confuse COPD with chronic asthma in older subjects; heavy smoking history, evidence of emphysema on imaging, decreased diffusing capacity, and chronic hypoxemia favor COPD. 2
• Patients using combination ICS/LABA therapy should not use additional LABA for any reason. 7

Follow-Up Requirements

• If no improvement within two weeks of treatment, obtain chest radiography and consider hospital referral. 3
• Arrange spirometry once acute symptoms resolve (if treating empirically) to confirm diagnosis and assess severity, which guides long-term treatment decisions. 3
• Document exercise tolerance at baseline to monitor future changes in breathlessness. 1