Acute bronchitis is a commonly encountered, self-limited, viral infection producing inflammatory changes within the larger airways of the lung. Sharing the viral pathogens of upper respiratory infections, including those of the common cold, acute bronchitis is often caused by one of the following: influenza A or B, parainfluenza, respiratory syncytial virus, or coronavirus.
The predominant cough of acute bronchitis may be productive and can easily last up to 3 weeks. Sputum purulence is usually indicative of sloughed inflammatory airway cells and, taken alone, does not indicate a bacterial etiology. Bronchitis lacks the suggestive symptoms and signs of pneumonia, specifically fever >38°C (100.4°F), adult heart rate >100 beats/min, and/or adult respiratory rate >24 breaths/min. Wheezing may be present.
Diagnosis and Differential
The diagnosis of acute bronchitis is made clinically with the following criteria: (a) acute onset cough (shorter than 3 weeks' duration), (b) absence of chronic lung disease history, (c) normal vital signs, and (d) no auscultatory abnormalities that suggest pneumonia. Pulse oximetry is indicated if the patient describes dyspnea or appears short of breath. Bedside peak flow testing may prove illustrative of reductions in forced expiratory volume in 1 second in over half of patients and is best indicated if wheezing is heard on examination. A chest radiograph is not required in non-elderly patients who appear nontoxic. Among the differential etiologies of cough prolonged beyond 3 weeks, consider pertussis in adolescents and young adults, particularly if eliciting a known contact with a confirmed pertussis case or coughing paroxysms with prominent posttussive emesis.
Emergency Department Care and Disposition
The use of antibiotics for acute bronchitis, while commonly requested by patients and prescribed by practitioners, does NOT confer clinically relevant benefits in a viral illness, but produces side effects such as gastrointestinal distress, vaginitis, and future pathogen resistance.
If pertussis is strongly suspected, azithromycin is indicated, in adults, day 1 with 500 milligrams orally, followed by days 2 to 5 with 250 milligrams orally. This treatment does not shorten the illness, but decreases coughing paroxysms and limits disease transmission.
Patients with evidence of airflow obstruction should be treated with bronchodilators. Albuterol by metered dose inhaler using a spacer, adult dosage of 2 puffs every 4 to 6 hours, is usually effective in symptomatic relief of dyspnea and cough reduction.
Additional agents for cough suppression, mucolysis, and symptomatic relief may be considered on an individual basis factoring comorbidities, drug interactions, and potential side effects.
Discharge instructions should encourage timely follow-up with a primary care physician, smoking cessation when applicable, and when to return to the emergency department based upon clinical symptoms.
Pneumonia, most commonly a bacterial infection of the alveolar lung, afflicts millions in the United States yearly, remaining a leading cause of morbidity and mortality. Pneumococcus (Streptococcus pneumoniae) is the classic bacterial etiology, ...