What is the treatment for acute bronchitis?

Acute Bronchitis: Definition and Treatment

Acute bronchitis is a self-limited inflammation of the large airways characterized by cough lasting up to 3 weeks, and antibiotics should not be routinely prescribed as they provide no significant benefit for most patients. 1

Definition and Clinical Presentation

Acute bronchitis is defined as:

• Self-limited inflammation of the large airways (bronchi)
• Cough lasting up to 3 weeks (primary symptom)
• May be productive or non-productive cough
• Often accompanied by mild constitutional symptoms
• Normal chest radiograph (no infiltrates)

The diagnosis should be made only after ruling out:

• Pneumonia (absence of tachycardia, tachypnea, fever, and abnormal chest exam findings)
• Common cold
• Acute asthma
• Exacerbation of COPD

Etiology

• More than 90% of cases are caused by respiratory viruses 1
• Bacterial pathogens account for fewer than 10% of cases
• Nonviral pathogens like Mycoplasma pneumoniae and Chlamydophila pneumoniae are occasionally identified
• Bordetella pertussis should be considered if community transmission is reported

Diagnostic Approach

For immunocompetent adult outpatients with suspected acute bronchitis:

• No routine investigations are recommended, including:

  • Chest x-ray
  • Spirometry or peak flow measurement
  • Sputum cultures
  • Viral PCR testing
  • Serum inflammatory markers (CRP, procalcitonin) 1

• Clinical evaluation should focus on ruling out pneumonia, which is unlikely in the absence of:

  • Tachycardia (heart rate >100 beats/min)
  • Tachypnea (respiratory rate >24 breaths/min)
  • Fever (oral temperature >38°C)
  • Abnormal chest examination findings (rales, egophony, tactile fremitus) 1

Treatment Recommendations

Antibiotics

Routine antibiotic treatment is not justified and should not be offered for uncomplicated acute bronchitis. 1

• Antibiotics do not significantly improve outcomes in most patients
• Antibiotics may decrease cough duration by only about 0.5 days 2
• Antibiotic use contributes to antibiotic resistance
• Antibiotics expose patients to potential adverse effects

Exception: Confirmed or suspected pertussis infection

• Macrolide antibiotics (e.g., erythromycin) should be prescribed
• Patient should be isolated for 5 days from start of treatment 1

Symptomatic Relief

1. Antitussives

   • May provide short-term symptomatic relief of coughing 1
   • Options include codeine or dextromethorphan
   • Limited evidence for effectiveness but reasonable for symptom management

2. Bronchodilators

   • Not routinely recommended for most patients with acute bronchitis 1
   • May be useful in select patients with wheezing accompanying cough 1
   • Albuterol has shown benefit in reducing cough duration in some studies 1

3. Expectorants

   • Guaifenesin may help loosen phlegm and thin bronchial secretions 3
   • Limited evidence for effectiveness in acute bronchitis

4. Other symptomatic measures

   • Adequate hydration
   • Humidified air
   • Avoidance of environmental irritants
   • Rest as needed

Patient Communication

Effective communication is crucial for patient satisfaction:

• Explain that acute bronchitis is typically viral and self-limiting
• Set realistic expectations about cough duration (typically 2-3 weeks)
• Consider referring to the condition as a "chest cold" rather than bronchitis 1
• Explain that colored sputum (green/yellow) does not indicate bacterial infection 1
• Discuss the risks of unnecessary antibiotic use

Follow-up Recommendations

If symptoms persist or worsen:

• Reassessment should be performed
• Consider targeted investigations such as:
  • Chest x-ray
  • Sputum for microbial culture
  • Peak flow measurements
  • Complete blood count
  • Inflammatory markers 1
• Consider antibiotic therapy only if a complicating bacterial infection is likely 1
• Evaluate for alternative diagnoses such as asthma, COPD, or bronchiectasis

Common Pitfalls to Avoid

1. Prescribing antibiotics based on sputum color (yellow/green does not indicate bacterial infection)
2. Failing to distinguish acute bronchitis from pneumonia, asthma, or COPD exacerbation
3. Not setting appropriate expectations about the typical duration of cough (2-3 weeks)
4. Overuse of bronchodilators in patients without evidence of bronchospasm
5. Inadequate patient communication about why antibiotics are not indicated

By following these evidence-based recommendations, providers can effectively manage acute bronchitis while reducing unnecessary antibiotic use and improving patient outcomes.