Design of the procedure. In all patients, the target sedation level before bronchoscopy was an Alaris auditory-evoked potential index (AAI) level between 25 and 40 and a Ramsay sedation scale (RSS) of 5 or 6. During bronchoscopy, patients were randomized to the auditory-evoked potentials (AEP) group or the RSS group. The sedative was adjusted in accordance with the AAI level or the RSS level. The AAI, heart rate, and mean arterial pressure were recorded every 5 min before flexible bronchoscopy and after flexible bronchoscopy.