 This study was designed to demonstrate that AQUAVAN is effective in providing adequate sedation in patients undergoing flexible bronchoscopy as well as to assess the safety profile of AQUAVAN versus that of midazolam. Prior to the procedure, patients receive fentanyl citrate for pain management followed five minutes later by either AQUAVAN Injection or midazolam HCl for sedation. During the procedure, study personnel assess the patients vital signs and depth of sedation. After the procedure, the patient, physician, and an evaluator are asked to complete satisfaction surveys. 