Dexmedetomidine to Prevent Agitation After Free Flap Surgery

Reconstruction using microvascular free tissue flap has been an important management in patients with maxillofacial tumor. It is often characterised as long operation time, more traumatic and require restriction of patient's head movement postoperatively in order to prevent disruption of microvascular anastomosis. Agitation and delirium are common in patients with free flap surgery, which may lead to serious consequences such as self extubation, injury or even failure of the flap. Dexmedetomidine is a sedative and co-analgesic drug with high specificity for α2-adrenoceptor. It is widely used in ICU sedation in general hospital. However its use after free flap surgery is not well documented. Furthermore the effect of Dexmedetomidine on preventing delirium has not been proved. The investigators hypothesized that the use of Dexmedetomidine would reduce emergence agitation and prevent delirium in patients after free flap surgery.