In all cases, patients will be monitored using continuous electrocardiography, pulse oximetry, and transcutaneous carbon dioxide (PtCO2, using a digital sensor placed on the patient's earlobe),and automated noninvasive blood pressure recordings every 5 minutes. All parameters will be recorded beginning from prior to connecting the patient to the nasal cannula before initiation of sedation, throughout the entire procedure and until 10 minutes after removal of the bronchoscope from the nasopharynx.