The effect of intraoperative dexmedetomidine on postoperative analgesia and sedation in pediatric patients undergoing tonsillectomy and adenoidectomy

Background: The immediate postoperative period after tonsillectomy and adenoidectomy, one of the most common pediatric surgical procedures, is often difficult. These children frequently have severe pain but postoperative airway edema along with increased sensitivity to the respiratory-depressant effects of opioids may result in obstructive symptoms and hypoxemia. Opioid consumption may be reduced by nonsteroidal antiinflammatory drugs, but these drugs may be associated with increased bleeding after this operation. Dexmedetomidine has mild analgesic properties, causes sedation without respiratory depression, and does not have an effect on coagulation. We designed a prospective, double-blind, randomized controlled study to determine the effects of intraoperative dexmedetomidine on postoperative recovery including pain, sedation, and hemodynamics in pediatric patients undergoing tonsillectomy and adenoidectomy. Methods: One hundred nine patients were randomized to receive a single intraoperative dose of dexmedetomidine 0.75 μg/kg, dexmedetomidine 1 μg/kg, morphine 50 μg/kg, or morphine 100 μg/kg over 10 minutes after endotracheal intubation. Results: There were no significant differences among the 4 groups in patient demographics, ASA physical status, postoperative opioid requirements, sedation scores, duration of oxygen supplementation in the postanesthetic care unit, and time to discharge readiness. The median time to first postoperative rescue analgesic was similar in patients receiving dexmedetomidine 1 μg/kg and morphine 100 μg/kg, but significantly longer compared with patients receiving dexmedetomidine 0.75 μg/kg or morphine 50 μg/kg (P < 0.01). In addition, the number of patients requiring >1 rescue analgesic dose was significantly higher in the dexmedetomidine 0.75 μg/kg group compared with the dexmedetomidine 1 μg/kg and morphine 100 μg/kg groups, but not the morphine 50 μg/kg group. Patients receiving dexmedetomidine had significantly slower heart rates in the first 30 minutes after surgery compared with those receiving morphine (P < 0.05). There was no significant difference in sedation scores among the groups. Conclusions: The total postoperative rescue opioid requirements were similar in tonsillectomy patients receiving intraoperative dexmedetomidine or morphine. However, the use of dexmedetomidine 1 μg/kg and morphine 100 μg/kg had the advantages of an increased time to first analgesic and a reduced need for additional rescue analgesia doses, without increasing discharge times.