A historically controlled pilot study was conducted in pediatric patients 18 months to 18 years of age hospitalized with a diagnosis of asthma or reactive airway disease and admitted to the pediatric intensive care unit. Upon receiving informed consent, patients were treated with HFCWO therapy via the VEST. The primary endpoint was time to readiness for discharge, lack of need for continued supportive care (e.g., intravenous fluid or oxygen), and bronchodilator treatments spaced at least four hours apart.