BRONCHITIS, ACUTE

BRONCHITIS, ACUTE - Alan J. Cropp, MD, FCCP
BASICS
DESCRIPTION
• Inflammation of trachea, bronchi, and bronchioles resulting from a respiratory tract infection or chemical irritant (1,2)
• Cough is the predominant symptom (3,4)
• Generally self-limited with complete healing and full return of function
• Most infections viral if no underlying cardiopulmonary disease is present
• Synonym(s): Tracheobronchitis
ALERT
Geriatric Considerations
Can be a serious illness in this age group, particularly if part of influenza or with underlying chronic obstructive pulmonary disease (COPD)
Pediatric Considerations
• In this age group, usually occurs in association with other conditions of upper and lower respiratory tract (trachea usually involved)
• Some children seem to be more susceptible than others (if repeated attacks, child should be evaluated for anomalies of the respiratory tract including immune deficiencies or for chronic asthma).
• If acute bronchitis is caused by respiratory syncytial virus, it may be fatal.
GENERAL PREVENTION
• Avoid smoking
• Control underlying risk factors (asthma, sinusitis, and reflux)
• Avoid exposure especially daycare
• Vaccinations, specifically pneumovax, influenza
EPIDEMIOLOGY
• Predominant age: All ages
• Predominant sex: Male = Female
Incidence
~5% of adults per year
Prevalence
Results in 10-12 million office visits per year
RISK FACTORS
• Chronic bronchopulmonary diseases
• Chronic sinusitis
• Bronchopulmonary allergy
• Hypertrophied tonsils and adenoids in children
• Immunosuppression
• Air pollutants
• Elderly
• Infants
• Smoking
• 2nd-hand smoke
• Alcoholism
• Gastroesophageal reflux disease (GERD)
• Tracheostomy
• Environmental changes
• Immunoglobulin deficiency
• HIV
Genetics
No known genetic pattern
PATHOPHYSIOLOGY
Acute bronchitis causes an injury to the epithelial surfaces resulting in an increase in mucous production (2)
ETIOLOGY
• Adenovirus
• Influenza A and B
• Parainfluenza
• Chlamydia pneumoniae (TWAR agent)
• Bordetella pertussis
• Respiratory syncytial virus
• Coxsackievirus
• Herpes simplex
• Haemophilus influenzae
• Possibly fungi
• Mycoplasma
• Secondary bacterial infection as part of an acute upper respiratory infection
• Streptococcus pneumoniae
• Moraxella catarrhalis
• Mycobacterium tuberculosis
• Rhinovirus
• Coronavirus (types 1-3)
• Chemical irritants
ASSOCIATED CONDITIONS
• Asthma
• Epiglottitis; rare but can be rapidly fatal
• Coryza
• Pharyngitis
• Croup
• Influenza
• Smoking
• Pneumonia
• Emphysema
• Sinusitis
• Bronchial obstruction
• GERD


DIAGNOSIS
PRE HOSPITAL
Usually treated as outpatient unless comorbidity exists
SIGNS AND SYMPTOMS
• Cough
• Fever
• Fatigue
• Aching (i.e., myalgia)
• Hemoptysis
• Chest burning
• Dyspnea (sometimes)
History
• Preceding respiratory tract infection, such as a common cold with coryza, malaise, chills, slight fever, sore throat, back and muscle pain
• Cough, initially dry and unproductive, then productive; later, mucopurulent sputum, which may indicate secondary infection
Physical Exam
• Rales, rhonchi, wheezing
• No evidence of pulmonary consolidation
• Pharynx injected
• Fever
• Tachypnea
TESTS
• Arterial blood gases: Hypoxemia (rarely)
• Leukocytosis
• Sputum culture/gram stain
• Viral titers
• Mycoplasma titers
• Pulmonary function tests (seldom needed during acute stages): Increased residual volume, decreased maximal expiratory rate (2)
Imaging
Chest radiograph
• Lungs normal if uncomplicated
• Helps rule out other diseases (pneumonia) or complications
Diagnostic Procedures/Surgery
Rarely indicated
DIFFERENTIAL DIAGNOSIS
• Asthma
• Allergy
• Eosinphilic Pneumonitis
• Influenza
• Bronchopneumonia
• Bronchiectasis
• Acute sinusitis
• Aspiration
• Cystic fibrosis
• Reactive airways dysfunction syndrome
• Bacterial tracheitis
• Retained foreign body
• Inhalation injury
• Heart failure
• Bronchogenic carcinoma
• GERD
TREATMENT
PRE-HOSPITAL
Aerosolized bronchodilator may be helpful if patient has bronchospasm
STABILIZATION
• Outpatient unless elderly or complicated by severe underlying disease
• May require supplemental oxygen in selected cases
GENERAL MEASURES
• Rest
• Steam inhalations
• Vaporizers
• Antibiotics if complicated by comorbidity (e.g., COPD, severe asthma, etc.) (overused in United States)
• Adequate hydration
• Stop smoking
• Treat associated illnesses (e.g., GERD)
• Antitussives
Diet
Increased fluids (3-4 L/d) while febrile
Activity
Rest until fever subsides.
Nursing
Ensure patient comfort and moniter for signs of deterioration, especially if underlying lung disease exists.
SPECIAL THERAPY
IV Fluids
May be helpful if patient is dehydrated.
Complementary and Alternative Medicine
Throat lozenges for pharyngitis
MEDICATION (DRUGS)
First Line
• Meta-analysis has demonstrated the lack of efficacy of antibiotics in uncomplicated acute bronchitis. (5)[A]
• Amantadine or rimantadine therapy if influenza A suspected; most effective if started within 24-48 hours of development of symptoms (also consider tamiflu or relenza)
• Decongestants if accompanied by sinus condition (1)[B]
• Antipyretic analgesic such as aspirin or ibuprofen
• Antibiotics (Amoxicillin 500 mg q8h or TMP/SMX DS b.i.d) for more severe symptoms (high fever persists, concomitant COPD, purulent discharge)
• Amoxicillin: 500 mg q8h or trimethoprim sulfamethoxazole DS q12h for routine infection
• Doxycycline: 100 mg/d for 10 days if Moraxella, Chlamydia, or Mycoplasma suspected
• Clarithromycin (Biaxin): 500 mg q12h or azithromycin (Zithromax) Z-pack for PCN or sulfa allergy or mycoplasma infection
• Quinolone for more serious infection or other antibiotic failure or in elderly or multiple comorbidities
• Cough suppressant for troublesome cough (not with COPD); guaifenesin with codeine or dextromethorphan (4)[A]
• Inhaled beta agonist (e.g., albuterol) or in combination with steroids (2)[B]
• Consider steroids for bronchospasm
• Watch for theophylline toxicity with macrolides and quinolones. Macrolides also interfere with oral contraceptives.
• Significant possible interactions: Refer to the manufacturer's literature.
FOLLOW-UP
DISPOSITION
Usually a self-limited disease not requiring follow-up
Admission Criteria
Severe exacerbation of underlying disease
Discharge Criteria
Improvement in symptoms
Issues for Referral
Complications such as pneumonia
PROGNOSIS
• Usual: Complete healing with good return of function
• Can be serious in the elderly or debilitated
• Cough may persist for several weeks after an initial improvement (2)
• Postbronchitic reactive airways disease (rare)
• Bronchiolitis obliterans and organizing pneumonia (rare)
COMPLICATIONS
• Bronchopneumonia
• Acute respiratory failure
• Bronchiectasis
• Chronic cough
• Hemoptysis
• Superinfection
PATIENT MONITORING
• Oximetry until no longer hypoxemic
• Recheck for chronicity
REFERENCES
1. Flaherty K, Saint S, Fenfrick AM, Martinez F. The spectrum of acute bronchitis. Postgrad Med. 2001;109:39-47.
2. Knutson D, Braun C. Diagnosis and management of acute bronchitis. Am Fam Physician. 2002;65:2039-2044.
3. Snow V, Mottur-Pilson C, Gonzales R. Principles of appropriate antibiotic use for treatment of acute bronchitis in adults. Ann Intern Med. 2001;134:518-20.
4. Gonzales R, Bartlett J, Besser R, et al. Principles of appropriate antibiotic use for treatment of uncomplicated acute bronchitis: Background. Ann Intern Med. 2001;134:521-529.
5. MacKay DN: Treatment of acute bronchitis in adults without underlying lung disease. J Gen Intern Med. 1996;11(9):557-562.
MISCELLANEOUS
See also: Asthma; Chronic Obstructive Pulmonary Disease; and Emphysema