What is bronchitis and how is it treated?

Bronchitis: Definition and Treatment

Bronchitis is an inflammatory condition of the bronchi characterized by cough, with acute bronchitis being self-limited and lasting up to 3 weeks, while chronic bronchitis involves cough with sputum production occurring on most days for at least 3 months of the year for at least 2 consecutive years. 1, 2

Types of Bronchitis

Acute Bronchitis

• Definition: Acute respiratory infection with cough lasting up to 3 weeks, with or without sputum production
• Etiology: Predominantly viral (≥90% of cases), including influenza, parainfluenza, respiratory syncytial virus, coronavirus, adenovirus, and rhinoviruses 1, 2
• Non-viral causes (5-10% of cases): Bordetella pertussis, Mycoplasma pneumoniae, and Chlamydia pneumoniae 1

Chronic Bronchitis

• Definition: Cough with sputum expectoration occurring on most days for at least 3 months of the year and for at least 2 consecutive years 1
• Etiology: Primarily caused by interaction between noxious inhaled agents (cigarette smoke, industrial pollutants) and host factors (genetic predisposition, respiratory infections) 1
• Often associated with COPD as disease advances, with progressive airflow limitation and pathologic changes of emphysema 1

Diagnosis

Acute Bronchitis

• Clinical diagnosis based on acute cough with/without sputum production lasting up to 3 weeks
• Normal chest radiograph
• Absence of fever, tachycardia, tachypnea, or focal chest findings 2
• Diagnostic testing not indicated unless concern for pneumonia, influenza, or COVID-19 3

Chronic Bronchitis

• Clinical diagnosis based on definition criteria
• Exclusion of other respiratory or cardiac causes for chronic productive cough 1

Treatment

Acute Bronchitis

Antibiotics are not recommended for routine treatment of uncomplicated acute bronchitis, regardless of cough duration, as most cases are viral and self-limiting. 1, 2, 3

Key treatment principles:

1. Patient education:

   • Explain the viral nature of most cases
   • Inform about expected cough duration (2-3 weeks)
   • Refer to the condition as a "chest cold" rather than "bronchitis" to reduce antibiotic expectations 2

2. Symptomatic relief:

   • Hydration
   • Avoidance of respiratory irritants
   • Short-term use of codeine or dextromethorphan for cough relief 2
   • Consider bronchodilators for patients with wheezing 2

3. Evidence does NOT support:

   • Antitussives, honey, antihistamines, anticholinergics
   • Oral NSAIDs or inhaled/oral corticosteroids
   • Expectorants, postural drainage, or chest physiotherapy 2, 3

Chronic Bronchitis

The most effective way to reduce or eliminate cough in chronic bronchitis is avoidance of respiratory irritants, particularly smoking cessation. 1

Pharmacological management:

1. Bronchodilators:

   • Short-acting inhaled β-agonists
   • Inhaled ipratropium bromide
   • Oral theophylline (though not recommended for acute exacerbations) 1

2. Anti-inflammatory therapy:

   • Combined regimen of inhaled long-acting β-agonist and inhaled corticosteroid 1

3. Cough suppressants:

   • Central cough suppressants (codeine, dextromethorphan) for short-term symptomatic relief 1

4. Antibiotics:

   • Not recommended for prophylactic use 1
   • Only indicated for acute exacerbations with at least two Anthonisen criteria (increased dyspnea, sputum volume, and purulence) 2
   • For severe cases (FEV1 <35% and hypoxemia), immediate antibiotic treatment is recommended 2

Management of Acute Exacerbations of Chronic Bronchitis

When a stable patient with chronic bronchitis experiences sudden clinical deterioration with increased sputum volume, purulence, and/or worsening shortness of breath:

1. First-line treatments:

   • Inhaled bronchodilators
   • Oral antibiotics (if bacterial infection suspected)
   • Oral corticosteroids (or IV corticosteroids in severe cases) 1

2. Antibiotic selection:

   • Amoxicillin is preferred for most cases
   • Macrolides, doxycycline for beta-lactam allergy
   • Consider fluoroquinolones for patients with comorbidities, severe obstruction (FEV1 <50%), advanced age (>65 years), or recurrent exacerbations 2, 4

Common Pitfalls and Caveats

1. Overuse of antibiotics:

   • Antibiotics for acute bronchitis only decrease cough duration by approximately 0.5 days while exposing patients to adverse effects 3
   • Patient satisfaction depends more on effective communication than receiving antibiotics 2

2. Misdiagnosis:

   • Ensure proper differentiation from pneumonia, asthma, COPD exacerbation, and common cold 2
   • Consider pertussis, COVID-19, or influenza in appropriate clinical settings 3

3. Inadequate follow-up:

   • If cough persists beyond 3 weeks or worsens, further evaluation is necessary 2
   • Patients with underlying conditions require closer monitoring 2