Effect of dexmedetomidine on preventing agitation and delirium after microvascular free flap surgery: a randomized, double-blind, control study.

PURPOSE: To determine whether dexmedetomidine sedation in the postanesthesia care unit (PACU) could decrease agitation and delirium after free flap surgery.

MATERIALS AND METHODS: Eighty patients were randomly divided into 2 groups. In the experimental group, dexmedetomidine was given at an hourly infusion rate of 0.5 μg/kg for 1 hour before the operation was completed and continued in the PACU at 0.2 to 0.7 μg/kg continuously until the next morning. In the control group, normal saline was given during the same periods. Patients in the 2 groups received sufentanil and midazolam for sedation and pain relief when necessary. Agitation was monitored with the Riker Sedation-Agitation Scale in the PACU and delirium was monitored with the Confusion Assessment Method for the Intensive Care Unit for 5 days postoperatively.

RESULTS: The overall incidence of agitation was similar between the 2 groups. However, when the influence of patient shifting was excluded, the incidence of agitation in the dexmedetomidine group was apparently lower than that in the control group (10.3 vs 30%; P = .029). No difference was found in the occurrence of delirium between the experimental and control groups (5.1 vs 12.5%; P = .432).

CONCLUSION: Dexmedetomidine does not change the overall incidence of agitation after free flap surgery; however, it does decrease agitation after PACU admission. It does not prevent delirium within 5 days postoperatively.