What is the best course of action for an elderly patient with a one-month history of non-productive cough and dyspnea (difficulty breathing) that worsened over the past week, exacerbated by exertion, without chest pain, edema, or abnormal lung sounds?

Immediate Diagnostic Workup for Subacute Dyspnea in an Elderly Patient

This elderly patient requires chest radiography and spirometry as the mandatory first-line investigations to differentiate between cardiac, pulmonary parenchymal, and obstructive airway disease. 1

Initial Assessment Priority

The one-month duration with recent worsening defines this as a subacute presentation requiring systematic evaluation. The absence of abnormal lung sounds does not exclude significant pulmonary pathology—normal examination findings are common in moderate COPD and early interstitial processes. 1

Key Historical Details to Elicit

• Smoking history: Any patient >50 years with chronic breathlessness on minor exertion and smoking history should be presumed to have COPD until proven otherwise 1
• Occupational exposures: Stone mining, wood refinishing, mold exposure can cause interstitial lung disease 2, 3
• Medication history: ACE inhibitors cause chronic cough in a substantial proportion of patients and must be discontinued if present 1
• Systemic symptoms: Weight loss, fever, or night sweats suggest malignancy, infection, or connective tissue disease 4, 5
• Cardiac risk factors: Hypertension, diabetes, prior cardiac disease point toward cardiac dyspnea 1

Mandatory Initial Testing

Chest Radiography

Obtain immediately to exclude:

• Pneumonia (though absence of fever and normal lung sounds make this less likely) 1
• Pulmonary edema 1
• Malignancy 1
• Interstitial lung disease 1, 4
• Pleural effusion 1

Spirometry

Essential for diagnosis as symptoms and physical examination cannot reliably predict the degree of airflow obstruction. 1 This distinguishes:

• Obstructive pattern (COPD, asthma) with FEV1/FVC ratio reduced 1
• Restrictive pattern (interstitial disease) with reduced FVC and preserved ratio 4
• Normal spirometry requiring alternative investigation 1

Risk Stratification Based on Age

In elderly patients, the differential diagnosis shifts significantly:

• COPD prevalence increases steeply with consultation rates 2-4 times higher than angina in those aged 65-84 1
• CT abnormalities are common: Up to 20% of asymptomatic patients >70 years show bronchiectasis on screening CT 1
• Cardiac causes become more prevalent requiring echocardiography if cardiac origin suspected 1

Subsequent Investigation Algorithm

If Chest X-ray is Normal and Spirometry Shows Obstruction:

• Bronchial provocation testing to assess for asthma/cough-variant asthma 1
• Trial of inhaled corticosteroids (2-week oral steroid trial can exclude eosinophilic inflammation if no response) 1
• Consider GORD evaluation as reflux-associated cough occurs without GI symptoms 1

If Chest X-ray is Normal and Spirometry is Normal:

• High-resolution CT chest is indicated when initial workup is unrevealing in chronic cough 1
• Echocardiography to evaluate cardiac function and valvular disease 1
• Consider bronchoscopy only if foreign body aspiration suspected 1

If Chest X-ray Shows Abnormalities:

• CT chest with contrast for further characterization of infiltrates, masses, or interstitial changes 1
• Bronchoscopy if malignancy suspected 1
• Echocardiography if pulmonary edema pattern present 1

Common Pitfalls to Avoid

Do not assume normal lung sounds exclude significant disease. Physical examination has low sensitivity (59%) for detecting pulmonary pathology even with chest radiography. 1 Moderate COPD frequently presents with minimal or no abnormal signs despite significant airflow obstruction. 1

Do not empirically treat as acute bronchitis. The one-month duration exceeds the 3-week threshold defining chronic cough, and routine antibiotics are not indicated for uncomplicated bronchitis regardless of duration. 1

Do not delay spirometry. A firm COPD diagnosis requires objective measurement—relying on symptoms alone means patients with severe disease have been "missed" earlier in their disease course. 1

Do not order CT chest as first-line imaging. Studies show CT is noncontributory in 48 of 49 patients when performed without preceding abnormal chest radiograph or spirometry. 1 Reserve CT for patients with abnormal initial testing or high clinical suspicion despite normal radiograph. 1

Immediate Therapeutic Considerations

While awaiting diagnostic results:

• Discontinue ACE inhibitors immediately if the patient is taking them—no patient with troublesome cough should continue these medications 1
• Encourage smoking cessation as this is dose-related to cough and produces significant symptom remission 1
• Avoid empiric antibiotics unless pneumonia is radiographically confirmed 1