No tests, medications recommended for acute cough with suspected acute bronchitis in immunocompetent adults

Immunocompetent adult outpatients do not need testing or treatment for acute cough that is thought to be due to acute bronchitis, according to the CHEST Expert Cough Panel.

The panel reviewed evidence on diagnosis and management of cough due to acute bronchitis in adult immunocompetent outpatients in order to update the 2006 American College of Chest Physicians' guideline on the subject. The panel defined acute bronchitis as “an acute lower respiratory tract infection manifested predominantly by cough with or without sputum production, lasting no more than 3 weeks with no clinical or any recent radiographic evidence to suggest an alternative explanation.” A systematic review and updated evidence search were performed to address the role of investigations other than clinical assessment in patients who present with acute bronchitis, as well as the efficacy and safety of medications for cough in such patients. The panel's report was published Feb. 21 by CHEST.

The systematic review and updated evidence search did not identify eligible studies regarding the role of investigations, and only one eligible study looked at medications. In the latter study, a multicenter single-blinded randomized trial in 416 primary care patients who had had respiratory symptoms for less than one week, no difference was found in the number of days with cough among those who received an antibiotic and those who received an oral NSAID versus placebo. Based on these findings, the panel recommended against routine tests in the target population of immunocompetent adult outpatients with cough due to suspected acute bronchitis. If acute bronchitis persists or worsens, the panel suggested consideration of reassessment and targeted investigation, including chest X-ray, sputum for microbial culture, peak expiratory flow rate, complete blood count, and measurement of inflammatory markers (e.g., C-reactive protein level).

Regarding treatment, the panel suggested no routine prescription of antibiotics, antiviral therapy, antitussives, inhaled beta-agonists, inhaled anticholinergics, inhaled corticosteroids, oral corticosteroids, oral NSAIDs, or other therapies until research supporting their use becomes available. The panel suggested consideration of antibiotic therapy if acute bronchitis worsens and a complicating bacterial infection is thought to be likely. The panel noted that differential diagnoses such as chronic obstructive pulmonary disease, asthma, and bronchiectasis, which may require other treatments, should also be considered.

All of these recommendations were ungraded consensus statements due to the lack of available evidence, prompting the panel to call for studies of valid outcome measures to assess resolution of cough due to suspected acute bronchitis, as well as randomized controlled trials to assess the potential role of antibiotic and nonantibiotic treatments. “Patients with conditions that may mimic acute bronchitis such as cough variant asthma, acute exacerbations of chronic bronchitis, acute exacerbations of bronchiectasis, bacterial sinusitis and common cold should be excluded,” the panel members wrote. “Until these exclusionary conditions are considered and ruled out, the true frequency of acute bronchitis as a distinct clinical entity will not be known.”