SETTING: Medical Intensive Care Unit of Regions Hospital, a University of Minnesota-affiliated teaching hospital. PATIENT: Mechanically ventilated woman with status asthmaticus and acute respiratory failure. INTERVENTION: Observations of airway pressure and flow tracings before and after bronchoscopic inspection and airway lavage. MAIN RESULTS: Four newly observed signs were recorded that may serve to identify occult central airway mucus plugging in the ventilated asthmatic patient.