Pharmacologic Agents That Promote Airway Clearance in Hospitalized Subjects: A Systematic Review.

Pharmacologic agents to promote mucus clearance may reduce the sequelae of obstructive secretions. We systematically reviewed comparative studies of pharmacologic agents for mucus clearance in hospitalized or postoperative subjects without cystic fibrosis and over 12 months of age. We searched MEDLINE and other databases from January 1970 to July 2014 to identify relevant literature. Two reviewers independently assessed each study against predetermined inclusion/exclusion criteria. Two reviewers also independently extracted data regarding subject and intervention characteristics and outcomes and assigned overall quality ratings. The 9 studies meeting review criteria included 5 randomized controlled trials, 3 crossover randomized controlled trials, and one retrospective cohort study. Studies were small and together included a total of 379 subjects (mean of 42 subjects per study). N-acetylcysteine, heparin plus N-acetylcysteine, albuterol, ipratropium bromide, and saline were assessed. Studies reported no benefit of studied agents on expectoration, pulmonary function, and atelectasis and little effect on changes in sputum volume, weight, or viscosity. Adverse effects of agents were not consistently reported. Nausea was reported in 2 studies of N-acetylcysteine (one paper reported 2 experiments and did not clearly identify in which experiment adverse effects occurred), 3 studies reported that there were no adverse events, and 3 studies did not address adverse effects at all. Further research with clearly characterized populations and interventions is needed to understand the potential benefits and adverse effects of mucoactive agents.