What are the diagnostic criteria and treatment options for bronchitis?

Bronchitis Diagnosis and Treatment

Diagnostic Approach

Acute bronchitis is a clinical diagnosis based on acute cough with or without sputum production, and routine diagnostic testing should NOT be performed. 1, 2

When to Diagnose Acute Bronchitis

• Diagnose clinically when patient presents with acute cough (lasting 1-3 weeks) with or without sputum production 1, 2, 3
• Critical distinction: Acute bronchitis must be differentiated from pneumonia, asthma exacerbation, COPD exacerbation, and pertussis 1, 3
• Purulent sputum does NOT distinguish bacterial infection from viral bronchitis and should not guide antibiotic decisions 2, 4

When Chest X-Ray is NOT Needed

Safely avoid chest radiography if ALL four of the following are absent: 2

• Heart rate >100 beats/min
• Respiratory rate >24 breaths/min
• Oral temperature >38°C
• Focal consolidation, egophony, or fremitus on chest examination

If ANY of these findings are present, obtain chest X-ray to rule out pneumonia, especially in elderly patients 2

Tests to AVOID in Typical Acute Bronchitis

• Do NOT obtain viral cultures 2
• Do NOT obtain serologic assays 2
• Do NOT obtain sputum analyses 2
• Do NOT obtain inflammatory markers like CRP 1
• Do NOT obtain chest radiographs if pneumonia criteria absent 2

Chronic Bronchitis Diagnosis

Diagnose chronic bronchitis when: 2

• Chronic cough and sputum production occurring most days for at least 3 months per year for 2 consecutive years
• After excluding other respiratory or cardiac causes

Obtain complete exposure history including: 2

• Cigarette, cigar, and pipe smoking (responsible for 85-90% of cases)
• Passive smoke exposure
• Occupational and environmental hazards

Treatment Recommendations

Acute Bronchitis in Adults

Do NOT routinely prescribe antibiotics, antivirals, antitussives, inhaled beta-agonists, inhaled anticholinergics, inhaled corticosteroids, oral corticosteroids, or oral NSAIDs. 1

Key treatment principles: 1, 3

• Acute bronchitis is self-limiting (cough typically lasts 2-3 weeks)
• Antibiotics decrease cough duration by only 0.5 days but expose patients to adverse effects 3
• Viruses cause >90% of cases 5, 4
• Focus on patient education about expected duration of symptoms 3

Consider antibiotics ONLY if: 1

• Acute bronchitis worsens and complicating bacterial infection is suspected
• Pertussis is suspected (to reduce transmission) 4
• Patient is at increased risk of pneumonia (age ≥65 years) 4

Important caveat: Up to 65% of patients with recurrent "acute bronchitis" episodes may actually have mild asthma—consider this diagnosis in patients with repeated episodes 1

Acute Exacerbations of Chronic Bronchitis

Reserve antibiotics for patients with at least ONE cardinal symptom AND ONE risk factor: 2, 6

Cardinal symptoms (need ≥1):

• Increased dyspnea
• Increased sputum production
• Increased sputum purulence

Risk factors (need ≥1):

• Age ≥65 years
• FEV1 <50% predicted
• ≥4 exacerbations in 12 months
• Comorbidities

Antibiotic selection: 6

• Moderate severity: Newer macrolide, extended-spectrum cephalosporin, or doxycycline
• Severe exacerbation: High-dose amoxicillin/clavulanate or respiratory fluoroquinolone

Supportive care for ALL patients: 6

• Remove irritants (smoking cessation is PRIMARY intervention) 7, 2
• Bronchodilators
• Oxygen if needed
• Hydration
• Consider systemic corticosteroids
• Chest physical therapy

Bronchiolitis in Children (<2 years)

Do NOT routinely use: 1

• Bronchodilators (unless documented positive response to trial)
• Corticosteroids
• Antibiotics (unless specific bacterial coexistence)
• Chest physiotherapy
• Ribavirin

Diagnose based on history and physical examination—do NOT routinely order laboratory or radiologic studies 1, 2

Assess risk factors for severe disease: 1, 2

• Age <12 weeks
• Prematurity
• Hemodynamically significant congenital heart disease
• Chronic lung disease
• Immunodeficiency

Oxygen therapy: 1

• Indicated if SpO2 persistently falls below 90%
• Maintain SpO2 ≥90%
• Discontinue when SpO2 ≥90%, feeding well, and minimal respiratory distress

Adult Bronchiolitis (Distinct Entity)

Adult bronchiolitis is fundamentally different from pediatric viral disease and requires cause-specific treatment: 7

Mandatory comprehensive evaluation before treatment: 7

• Spirometry with and without bronchodilator
• Lung volumes and gas exchange testing
• Chest radiograph and high-resolution CT with expiratory cuts
• Bronchoscopy when bacterial suppurative disease cannot be excluded
• Surgical lung biopsy when diagnosis uncertain

Treatment based on etiology: 7

• Infectious bacterial bronchiolitis: Prolonged antibiotic therapy
• Respiratory bronchiolitis (smoking-related): Smoking cessation is primary intervention
• Toxic/antigenic exposure or drug-related: Cessation of offending agent PLUS corticosteroids for those with physiologic impairment

Do NOT apply pediatric bronchiolitis treatment paradigms to adults 7

Common Pitfalls to Avoid

• Do not prescribe antibiotics based on sputum color alone—purulent sputum does not indicate bacterial infection in acute bronchitis 2, 4
• Do not confuse acute bronchitis with pneumonia—use clinical criteria to determine need for chest X-ray 2
• Do not miss underlying asthma—consider in patients with recurrent "bronchitis" episodes 1
• Do not apply adult acute bronchitis guidelines to chronic bronchitis exacerbations—these require different treatment algorithms 2, 6
• Do not apply pediatric bronchiolitis guidelines to adults—adult bronchiolitis is a distinct disease requiring targeted therapy 7