• Sedation success defined for a patient as having 3 consecutive Modified OAA/S scores <=4 and completing the procedure without requiring alternative sedative medications and without requiring manual or mechanical ventilation.
  

• Secondary Efficacy Endpoints
  
• Time to Fully Recovered from end of procedure
  
• Time to Fully Alert from end of procedure
  
• Change from baseline DSST score over time during recovery period
  
• Modified OAA/S scores over time during the dosing initiation, procedural, and recovery periods
  
• Duration and percent of time when a patient's Modified OAA/S score is at each level between the first dose of study medications and Fully Alert, inclusive
  
• Duration of sedation
  
• Number of doses of study medication administered for the procedure
  
• Time to sedation
  
• Number of procedure interruptions due to inadequate sedation
  
• Patient's rating of experience after Fully Recovered
  
• Patient's rating at 24 hour post-discharge telephone survey
  
• Investigator's rating at end of procedure
  
• Blinded evaluator's rating after patient is Fully Recovered
  
• Safety Endpoints
  
• Nature, frequency, severity, relationship to treatment, and outcome of all adverse events
  
• Sedation-related adverse events and interventions
  
• Laboratory parameters and vital signs
  
• Airway assistance
  
• Concomitant medications
  

This is a randomized, open-label study designed to assess the safety and efficacy of AQUAVAN® Injection versus midazolam HCl following pretreatment with an analgesic, fentanyl citrate injection, in producing sedation in patients undergoing a flexible bronchoscopy procedure. Randomization will be stratified by site. Following completion of pre-procedure sedation assessments, patients will be randomly assigned to 1 of the 2 i.v. treatment groups at a 3:1 (AQUAVAN® Injection: midazolam HCl) allocation ratio. All study patients, irrespective of treatment group assignment, will receive fentanyl citrate injection as an analgesic pretreatment. Supplemental doses of fentanyl citrate injection may be administered if the patient reports pain or if inadequate analgesia is present as demonstrated by increased heart rate and/or blood pressure in the presence of adequate sedation. At no time should fentanyl citrate injection be administered to increase sedation levels. AQUAVAN® Injection and midazolam HCl will be administered to induce a state of adequate sedation, defined as a Modified Observer's Assessment of Alertness / Sedation (OAA/S) score of 4 or less.

Supplemental doses will be administered to increase depth or duration of sedation. Supplemental doses will not be administered if the Modified OAA/S score is 2 or less or if there is no purposeful response to stimulation. The depth of sedation will be measured by the Modified OAA/S scale, a validated measure. Patient and Investigator assessments will be used to confirm that the depth of sedation provided met the goals of sedation, reduction of anxiety and reduced awareness.