Chapter 10-3: Acute Bronchitis

TEXTBOOK PRESENTATION

Acute bronchitis presents in the healthy adult primarily as a cough of 1–3 weeks duration. Myalgias and low-grade fevers may be seen. This is distinct from an acute exacerbation of COPD (see Chapter 33-8: Chronic Obstructive Pulmonary Disease (COPD)).

DISEASE HIGHLIGHTS

1. Etiology

   1. Viruses (including influenza, parainfluenza, respiratory syncytial virus, adenovirus, rhinovirus and coronavirus)

   2. Bacterial

      1. Bacteria cause < 10% of cases

      2. Organisms include Bordetella pertussis, Mycoplasma, and Chlamydia.

   3. Noninfectious

      1. Asthma

      2. Pollution

      3. Tobacco

      4. Cannabis

2. Symptoms

   1. Initial phase: Cough and systemic symptoms secondary to infection are seen.

   2. Fever absent or low grade. Consider pneumonia in patients whose fever is high-grade (> 38°C) or persistent.

   3. Protracted phase

      1. 40–65% of patients without prior pulmonary disease show evidence of reactive airway disease during acute bronchitis.

      2. In 26% of patients, cough persists secondary to bronchial hyperresponsiveness and lasts ≥ 2–4 weeks.

EVIDENCE-BASED DIAGNOSIS

1. Sputum may be clear or discolored. Discoloration arises from tracheobronchial epithelium cells and WBCs and is not diagnostic of bacterial infection.

   Purulent sputum is not an indication for antibiotic therapy in patients with acute bronchitis.

2. Chest film is not routine but should be obtained when pneumonia is being considered (see Figure 10-1); indications include any of the following:

   1. Patients at risk for pneumonia: elderly patients and those with heart, lung, kidney disease or who are immunocompromised

   2. Symptoms of dyspnea, high fever, rigors, pleuritic chest pain, or altered mental status

   3. Abnormal vital signs including high fever (temperature > 38°C), tachypnea (RR > 24 breaths per minute), tachycardia (HR > 100 bpm)

   4. Focal findings on lung exam or hypoxemia

3. Testing for influenza can be considered in febrile patients who present during influenza season within 48 hours of symptoms onset in whom antiviral therapy is being considered (see above).

TREATMENT

1. Antibiotics

   1. Antibiotics do not provide major clinical benefit and are not recommended for most patients with acute bronchitis.

   2. Influenza treatment shortens the course of illness in patients with influenza treated within 48 hours of symptoms (see above) and can be considered in patients with bronchitis due to this pathogen.

2. Bronchodilators significantly reduce cough in patients with bronchial hyperreactivity, wheezing, or airflow obstruction at baseline.

3. Antitussives and expectorants are useful symptomatic measures.