Observational study of dexmedetomidine for hysteroscopy, cystoscopy and transrectal ultrasound biopsy.

Dexmedetomidine shows promise of being an airway-stable drug. It is approved in Australia for procedural sedation. However, it is important to note that in the study on which this indication is based, all the subjects received a local anaesthetic block before their procedure or surgery. In this regard, as Health Canada has explicitly stated, further evidence still needs to be gained for the use of dexmedetomidine for procedural sedation without accompanying nerve blocks. The purpose of this current proof-of-concept, observational study is to provide further information about dexmedetomidine in three regards. First, can dexmedetomidine be used for procedural sedation per se (i.e. without local anaesthetic blocks)? Second, as opposed to results being averaged out over a wide variety of procedures, the current study examined the feasibility of dexmedetomidine-based procedural sedation for three specific procedures. Third, the current study aims to add to the pool of information regarding the appropriate dose of dexmedetomidine. As described in the dexmedetomidine product information, the Observer's Assessment of Alertness/Sedation Scale grades sedation from 5 (alert) down to 1 (deepest level of sedation). In the study on which dexmedetomidine's indication for procedural sedation is based, patients needed only to achieve a score of 4 and, thus, the approved product information recommends a loading dose of 1.0 µg/kg followed by a maintenance infusion of 0.2 to 1.0 µg/kg/hour. This current study aims to add to the literature regarding the safety of dexmedetomidine when used at higher than recommended doses.