Analgesic and sedative effects of intranasal dexmedetomidine in third molar surgery under local anaesthesia.

Background: Dexmedetomidine (DEX) is an alpha 2-adrenoreceptor agonist, which induces sedation and analgesia. This study aimed to determine whether intranasal DEX offered perioperative sedation and better postoperative analgesia.
Methods: Patients having unilateral third molar surgery under local anaesthesia were recruited and allocated to receive either intranasal DEX 1 µg kg(-1) (Group D) or same volume of saline (Group P) 45 min before surgery. Patient-controlled sedation with propofol was offered as a rescue sedative. Perioperative sedation, postoperative pain relief and analgesic consumption, vital signs, adverse events, postoperative recovery, and satisfaction in sedation and analgesia were assessed.
Results: Thirty patients from each group were studied. Areas under curve (AUC) of postoperative numerical rating scale (NRS) pain scores 1-12 h at rest and during mouth opening were significantly lower in Group D (P=0.003 and 0.009, respectively). AUC BIS values and OAA/S sedation scores were significantly lower before surgery and at the recovery area (all P<0.01) with significantly less intra-operative propofol used in group D (P<0.01). In group D, heart rate was significantly lower at recovery period (P=0.005) while systolic blood pressure in different periods of the study (all P<0.01), but the decreases did not require treatment. More patients from placebo group experienced dizziness (P=0.026) but no serious adverse event was found. No difference was found in postoperative psychomotor recovery and satisfaction in pain relief and sedation.
Conclusions: Patients receiving intranasal DEX for unilateral third molar surgery with local anaesthesia were more sedated perioperatively with better postoperative pain relief. No delay in psychomotor recovery was seen.