Effect of Adding Dexmedetomidine to Bupivacaine for Caudal Analgesia in Major Abdominopelvic Surgeries in Pediatrics

Background: Caudal anaesthesia is the most common regional technique for regional anaesthesia in pediatrics. However, many adjuvants are now used to prolong its analgesic effect. In this study we investigate the addition of dexmedetomidine to bupivacaine in caudal analgesia for major abdominopelvic surgeries in pediatrics. Methods: Sixty children ASA I or II, males and females, aged 6 months to 3 years, undergoing elective abdominopelvic surgical procedures expected to last more than 90min., and scheduled to receive general anesthesia combined with caudal extradural block were recruited. Anesthesia was induced via face mask with sevoflurane 5% in 100% oxygen. Using standard monitoring and after receiving atropine (0.02mg/kg IV) and atracurium (0.5mg/kg IV), intubation using a suitable sized endotracheal tube was done. Anesthesia was maintained with isoflurane and top up doses of atracurium 0.1mg/kg every 20 minutes and controlled mechanical ventilation. Children were randomly allocated to two groups to receive a caudal injection; CB Group (n=20): Received caudal solution of total amount of 1ml/kg containing bupivacaine 0.25% diluted in saline, while CD Group (n=20): Received caudal solution of total amount of 1ml/kg containing bupivacaine 0.25% plus dexmedetomidine 1μg/kg diluted in saline. Intraoperative hemodynamic (heart rate and blood pressure) were observed along with the need for intraoperative fentanyl analgesia (1μg/kg). Also postoperative hemodynamics (heart rate, blood pressure and SpO 2) were observed with assessment of analgesia, CHIPP score, duration of motor block sedation, and development of any side effects until 2 h after the end of surgery. Results: Hemodynamics (intra and postoperative) showed lower and more stable readings in CD group compared to CB group starting at 60 minutes intraoperative and continuing till the end of two hours postoperative. Intraoperative fentanyl was consumed by 8 patients (45%) in CB group compared to none (0%) in CD group (p=0.0005). Postoperative CHIPP Score showed significantly lower readings in the CD group compared to CB group (p=0.000 1) throughout the postoperative period. Duration of analgesia was significantly longer in the CD group (10.3 ± 1.65) compared to CB group (4.725 ±3.05) (p=0. 00 1). Duration of motor block, sedation score, postopCorrespondence to: Dr. Dalia Khaled, The Department of Anaesthesiology, Faculty of Medicine, Cairo University erative side effects (urine retention, nausea and vomiting, pruritis and respiratory depression) showed no statistical significant difference between the study groups. Conclusion: Addition of dexmedetomidine 1μg/kg to bupivacaine 0.25% significantly increases potency of intraoperative analgesia and prolongs the duration of postoperative analgesia with reduction of analgesic requirements and preserved hemodynamic stability, lower postoperative pain score, lack of sedation and postoperative side effects thus allowing single shot caudal analgesia to be recommended for surgeries lasting 90-120min.