In a recent report of awake flexible bronchoscopic intubations, Yang et al.  described associated events that included hemodynamic instability and desaturation. Midazolam, propofol, fentanyl, ketamine, and dexmedetomidine were listed as the anesthetic agents.

Droperidol was one of the first drugs used for awake intubations and bronchoscopy and has continued to be a viable option after anesthetizing the oropharynx with local anesthetics or nerve blocks.  Ferrari and Stephen first presented the use of droperidol and fentanyl, termed neurolept anesthesia, for bronchoscopy and endoscopy.  The range of the droperidol dosing was 8 to 30 mg (0.15 mg/kg) with 100 to 600 μg fentanyl.  During the procedures, the patients remained cooperative and followed requests for taking opening the mouth, taking deep breaths, holding breaths, and coughing when asked.  These observations were for the more stimulating rigid bronchoscopy that antedated the advent of flexible bronchoscopy reported one year later. 

Droperidol will not cause respiratory depression and provides hemodynamic stability. Pharyngeal anesthesia with 2% or 4% lidocaine is a prerequisite. After 2.5 mg droperidol, and the administration of 1 to 2 mg midazolam, 50 to 100 μg fentanyl, and 25 to 50 mg diphenhydramine, patients are cooperative and excellent intubating conditions for awake flexible intubations have been established.

It is well known that droperidol, among many drugs used by anesthesiologists, may cause QT prolongation. The black box warning for this drug has been refuted.  An evidenced based review of cardiac events with droperidol revealed the dosages used were as high as 600 mg IV in patients being treated for psychosis who also received multiple prolonging the QT medications.  A QT interval greater than 500 ms or a change greater than 60 ms from baseline is clinically significant but there is no defined threshold to consider free from the risk of torsades.  The 2.5 mg droperidol dose is within the approved range of the Food and Drug Administration and can be increased as needed dependent upon the clinical situation, the absence of other QT prolonging drugs, and patient comorbidities.