Comparison of Dexmedetomidine and Fentanyl as an Adjuvant to Ropivacaine for Postoperative Epidural Analgesia in Pediatric Orthopedic Surgery

Purpose: Opioids are commonly used as an epidural adjuvant to local anesthetics, but are associated with potentially serious side effects, such as respiratory depression. The aim of this study was to compare the efficacy and safety of dexmedetomidine with that of fentanyl as an adjuvant to epidural ropivacaine in pediatric orthopedic surgery. Materials and Methods: This study enrolled 60 children (3-12 years old) scheduled for orthopedic surgery of the lower extremities and lumbar epidural patient-controlled analgesia (PCA). Children received either dexmedetomidine (1 mu g/kg) or fentanyl (1 mu g/kg) along with 0.2% ropivacaine (0.2 mL/kg) via an epidural catheter at 30 minutes before the end of surgery. Postoperatively, the children were observed for ropivacaine consumption via epidural PCA, postoperative pain intensity, need for rescue analgesics, emergence agitation, and other adverse effects. Results: The mean dose of bolus epidural ropivacaine was significantly lower within the first 6 h after surgery in the dexmedetomidine group, compared with the fentanyl group (0.029 +/- 0.030 mg/kg/h vs. 0.053 +/- 0.039 mg/kg/h, p=0.012). The median pain score at postoperative 6 h was also lower in the dexmedetomidine group, compared to the fentanyl group [0(0-1.0) vs. 1.0 (0-3.0), p=0.039]. However, there was no difference in the need for rescue analgesia throughout the study period between groups. Conclusion: The use of dexmedetomidine as an epidural adjuvant had a significantly greater analgesic and local anesthetic-sparing effect, compared to fentanyl, in the early postoperative period in children undergoing major orthopedic lower extremity surgery.