What are the recommended initial labs and treatment for a patient presenting with shortness of breath and chronic cough?

Recommended Initial Labs and Treatment for Shortness of Breath and Chronic Cough

The initial diagnostic approach for patients with shortness of breath and chronic cough should focus on detecting upper airway cough syndrome (UACS), asthma, non-asthmatic eosinophilic bronchitis (NAEB), and gastroesophageal reflux disease (GERD), as these are the most common causes that require specific testing and treatment. 1

Initial Diagnostic Workup

Mandatory Initial Tests

• Chest radiograph - Essential first-line test for all patients with chronic cough 1
• Spirometry with bronchodilator response - Mandatory to identify airflow obstruction 1

Additional Testing Based on Initial Findings

1. If normal chest radiograph and spirometry:

   • Bronchoprovocation challenge (BPC) - To evaluate for asthma when spirometry doesn't show reversible airflow obstruction 1
   • Induced sputum test for eosinophils - To diagnose NAEB if available 1

2. If suspicion for pulmonary embolism (particularly with acute worsening of shortness of breath):

   • D-dimer testing - High sensitivity for ruling out PE when negative in appropriate clinical context 2, 3
   • CT pulmonary angiogram - If D-dimer positive or high clinical suspicion 4

Stepwise Treatment Approach

Step 1: Address Modifiable Factors

• Smoking cessation for smokers - 90% of patients will have resolution of cough after smoking cessation 1
• Discontinue ACE inhibitors if patient is taking them 1

Step 2: Sequential Empiric Treatment

Treatment should be given in sequential and additive steps as multiple causes may coexist 1:

1. First: Treat for UACS

   • Trial of first-generation antihistamine/decongestant 1
   • In presence of prominent upper airway symptoms, add topical nasal corticosteroids 1

2. Second: Treat for Asthma (if UACS treatment fails)

   • If BPC positive: Combination of inhaled corticosteroids and inhaled β-agonists 1
   • If BPC unavailable: Empiric trial of asthma therapy 1

3. Third: Treat for NAEB (if asthma treatment fails)

   • If induced sputum shows eosinophilia: Inhaled corticosteroids
   • If sputum testing unavailable: Empiric trial of oral corticosteroids (2 weeks) 1

4. Fourth: Treat for GERD (if above treatments fail)

   • Intensive acid suppression with proton pump inhibitors and alginates for minimum 3 months 1

For Chronic Bronchitis (if applicable)

• Short-acting inhaled β-agonists (e.g., albuterol)
• Inhaled ipratropium bromide
• Combined long-acting β-agonist and inhaled corticosteroid regimen 1

Important Clinical Considerations

• Character of cough or timing is not reliable for determining cause 1
• Presence/absence of sputum should not dictate clinical approach 1
• Multiple causes of chronic cough often coexist, requiring sequential treatment trials 1
• Cough may be the only manifestation of UACS, asthma, or GERD ("silent GERD") 1
• Monitor treatment response using both subjective and objective methods 1

Common Pitfalls to Avoid

• Failing to obtain chest radiograph - Essential to rule out serious pathology
• Overlooking GERD as a cause when gastrointestinal symptoms are absent 1
• Stopping diagnostic workup prematurely - Multiple causes often coexist
• Relying on single peak expiratory flow measurements - Less accurate than spirometry 1
• Continuing ACE inhibitors - No patient with troublesome cough should remain on these medications 1

If cough persists despite this systematic approach, referral to a cough specialist is indicated 1.