Intraoperative administration of dexmedetomidine reduces the analgesic requirements for children undergoing hypospadius surgery

BACKGROUND: The present study was designed to assess whether an intraoperative administration of dexmedetomidine would decrease the intraoperative and postoperative analgesic requirements for paediatric patients undergoing hypospadius surgery. METHODS: Forty-eight children (American Society of Anesthesiologists-1) aged 1-12 years undergoing hypospadius repair under general anaesthesia were randomly assigned into dexmedetomidine or placebo groups, D and P, respectively. Group D received a loading dose of dexmedetomidine 1 microg kg(-1) after induction of anaesthesia, followed by a continuous infusion at a rate of 0.7 microg kg(-1) h(-1). Group P received a volume-matched 0.9% saline. Both groups received fentanyl for intraoperative analgesia and intravenous morphine and oral paracetamol for postoperative analgesia. For both groups, heart rate, blood pressure and fentanyl requirements were recorded intraoperatively. During their stay for 2 h in the recovery room, heart rate, blood pressure, pain scores, behaviour scores and total morphine requirements were recorded. After discharge from postanaesthesia care unit, paracetamol requirements over 24 h were also recorded. RESULTS: Intraoperatively, the dexmedetomidine-treated group had significantly fewer fentanyl requirements, slower heart rate and lower mean arterial blood pressure (P < 0.001). In the postanaesthesia care unit, this group also consumed significantly less morphine, had lower pain scores, lower behaviour score in the immediate postoperative period, lower heart rates and mean arterial blood pressures when compared with the placebo group (P < 0.001). Group D consumed significantly less paracetamol than group P in the ward over 24 h. CONCLUSION: Intravenous administration of dexmedetomidine intraoperatively during hypospadius repair in children reduces intraoperative and postoperative analgesic requirements and lowers heart rate and blood pressure.