What are the diagnostic criteria and treatment options for bronchitis?

Diagnostic Criteria and Treatment Options for Bronchitis

For acute bronchitis, no routine prescription of antibiotics, antivirals, antitussives, bronchodilators, corticosteroids, or NSAIDs is recommended as these treatments have not been shown to significantly improve outcomes. 1, 2

Diagnostic Criteria

Acute Bronchitis

Acute bronchitis is a clinical diagnosis characterized by:

• Acute cough lasting up to 3 weeks
• May include sputum production (purulent or non-purulent)
• Normal chest radiograph
• Absence of pneumonia, common cold, acute asthma, or COPD exacerbation 1

To rule out pneumonia (no chest X-ray needed) if ALL of the following are absent:

• Heart rate > 100 beats/min
• Respiratory rate > 24 breaths/min
• Oral temperature > 38°C
• Focal chest examination findings (consolidation, egophony, fremitus) 1, 2

Chronic Bronchitis

Defined as:

• Daily productive cough for at least 3 consecutive months
• Present for at least 2 consecutive years 1, 2

Classified into three stages:

1. Simple chronic bronchitis: Chronic cough and expectoration without dyspnea, FEV1 > 80%
2. Obstructive chronic bronchitis: Exertional dyspnea and/or FEV1 between 35% and 80%
3. Obstructive chronic bronchitis with respiratory insufficiency: Dyspnea at rest and/or FEV1 < 35% and hypoxemia at rest 1

Treatment Options

Acute Bronchitis

Non-Pharmacological Management

• Patient education about expected duration of cough (2-3 weeks)
• Explanation of viral etiology and self-limiting nature
• Hydration
• Avoidance of respiratory irritants 2, 3

Pharmacological Management

• Antibiotics: Generally not indicated for uncomplicated acute bronchitis 1, 2, 4

  • Consider only for:
    • Suspected or confirmed pertussis (macrolides)
    • Patients with underlying pulmonary disease and frequent exacerbations
    • Patients ≥65 years at high risk for pneumonia
    • If bacterial infection is suspected when condition worsens 1, 2

• Symptomatic relief:

  • Short-term use of codeine or dextromethorphan for cough suppression 1, 2
  • Honey (one teaspoon) for adults and children >1 year 2

• Reassessment: If symptoms worsen or persist beyond 3 weeks, consider:

  • Chest X-ray
  • Sputum culture
  • Complete blood count
  • Inflammatory markers such as CRP 1

Chronic Bronchitis

Non-Pharmacological Management

• Smoking cessation (most effective intervention - 90% of patients will have resolution of cough) 1, 2
• Avoidance of respiratory irritants 1

Pharmacological Management for Stable Chronic Bronchitis

• Short-acting β-agonists: For bronchospasm, dyspnea, and chronic cough (Grade A recommendation) 1
• Ipratropium bromide: To improve cough (Grade A recommendation) 1
• Long-acting β-agonist with ICS: For chronic cough control (Grade A recommendation) 1
• ICS therapy: For patients with FEV1 < 50% predicted or frequent exacerbations (Grade A recommendation) 1
• Theophylline: Consider for chronic cough control with careful monitoring for complications (Grade A recommendation) 1

Management of Acute Exacerbations of Chronic Bronchitis

• Antibiotics: Recommended for patients with severe exacerbations and those with more severe airflow obstruction at baseline 1, 5

  • For patients with FEV1 ≥ 35%, consider amoxicillin-clavulanate or cefpodoxime-proxetil 1
  • For severe cases, consider azithromycin (500 mg once daily for 3 days) 6

• Bronchodilators: Short-acting β-agonists or anticholinergic bronchodilators during acute exacerbation 1

  • If no prompt response, add the other agent at maximal dose 1

• Corticosteroids: Short course (10-15 days) of systemic corticosteroids for acute exacerbations 1

Common Pitfalls and Caveats

1. Misdiagnosis: Up to one-third of patients diagnosed with acute bronchitis may actually have asthma or chronic bronchitis 1

2. Unnecessary antibiotic use: Despite evidence against routine use, 65-80% of acute bronchitis patients receive antibiotics, contributing to antibiotic resistance 1, 4

3. Ineffective treatments: Expectorants have not been proven effective for either acute or chronic bronchitis 1

4. Overlooking underlying conditions: Consider differential diagnoses such as asthma, COPD exacerbation, pneumonia, or heart failure 2, 3

5. Theophylline contraindication: Should not be used during acute exacerbations of chronic bronchitis 1

6. Long-term oral corticosteroids: Not recommended for stable chronic bronchitis due to lack of evidence for improving cough and high risk of side effects 1

By following these evidence-based diagnostic criteria and treatment approaches, clinicians can effectively manage both acute and chronic bronchitis while avoiding unnecessary interventions and potential complications.