Evaluation of the analgesic efficacy of local dexmedetomidine application.

Objectives: To determine the analgesic effects of locally applied dexmedetomidine in third molar surgery under general anesthesia.

Methods: Patients undergoing bilateral third molar surgery under general anesthesia were recruited into this double-blind, randomized, controlled study and were allocated to 3 study groups. Group D received preincision intravenous dexmedetomidine (1 mcg/kg) and direct infiltration of normal saline to the surgical wounds at the end of the surgery. Group P received preincision intravenous normal saline and direct infiltration of dexmedetomidine (1 μg /kg) to the surgical wounds at the end of the surgery. A control group (group N) received normal saline at both time points. Postoperative analgesic effects, analgesic consumption, global pain satisfaction score, vital signs, adverse events, and postoperative recovery were assessed.

Results: Thirty-three patients from each group were studied. Postoperative resting pain numerical rating scale scores were similar in all the groups. However, the areas under curves of numerical rating scale pain scores during mouth opening for 1 to 72 hours were significantly lower in group P than in group N (P=0.012). Both heart rate and systolic blood pressure in the immediate postoperative period were significantly lower in groups D and P than in group N (P<0.001). Patients from groups D and P were also more sedated than patients in group N (P=0.013 and P=0.007, respectively) but no difference in psychomotor recovery was observed. Respiratory rate, oxygen saturation, common side effects, wound infection rate, and global pain satisfaction scores were similar among the groups.

Conclusions: Dexmedetomidine seems to have an antihyperalgesic effect when administered locally after bilateral third molar surgery. There is no delay in psychomotor recovery or increase in postoperative clinically significant adverse events.