• The percentage of subjects requiring rescue midazolam to achieve and/or maintain
  
• proper sedation levels throughout the study drug infusion.
  

• Total dose of rescue midazolam required to achieve and/or maintain target sedation
  
• levels; percentage of subjects requiring additional rescue medications other
  
• than midazolam to achieve and/or maintain target sedation levels;
  
• anesthesiologist assessment of ease of subject care; and subject recall and
  
• satisfaction assessed 24 hours post study drug.
  

An awake fiberoptic intubation is indicated for any patient with an anticipated difficult airway because of their anatomy, airway trauma, morbid obesity, or unstable cervical spine injuries. An awake fiberoptic intubation in a non-sedated patient can be extremely stimulating, uncomfortable, and unpleasant. The clinician must focus on maintaining spontaneous breathing, hemodynamic stability, and the patient's comfort. The term "awake" fiberoptic intubation is used to distinguish this procedure from fiberoptic intubations performed under general anesthesia. Although patients may be sedated for "awake" fiberoptic intubation, they need to be responsive and capable of maintaining their own airway without assistance. Vital components of a successful awake fiberoptic intubation include an anesthesiologist experienced in this technique, adequate topicalization of the airway, and a sedated yet cooperative subject.

Benzodiazepines, combined with opioid, are commonly used for anxiolysis and/or analgesia during awake fiberoptic intubations.

Dexmedetomidine has sympatholytic, sedative, analgesic, and anxiolytic effects that attenuate the catecholamine response to perioperative stress. Dexmedetomidine sedates patients by decreasing sympathetic activity and the level of arousal. Furthermore, dexmedetomidine has been found to facilitate a decrease in salivary secretion, a desirable effect during fiberoptic intubations.

An estimated 100 subjects (50 DEX, 50 PBO) scheduled for an elective awake fiberoptic intubation because of a potentially difficult airway will be randomized prior to intubation at approximately 18 investigative sites.