Using Ketamine as Adjuvant to Bupivacaine for Caudal Analgesia in Major Abdominopelvic Surgeries in Pediatrics

Background: The commonest technique for regional anaesthesia in pediatrics is considered to be the caudal anaesthesia. The main disadvantage is short duration of single shot technique. However, with the help of adjuvants used, this can be overcome. In this study we compare addition of ketamine to bupivacaine in caudal analgesia for pediatrics undergoing major abdominopelvic surgeries.Methods: 60 pediatric patients of both genders, ASA I or II, age ranging from 6 months to 3 years, undergoing elective abdominopelvic surgical procedures expected to last more than 90min., and scheduled for general anesthesia combined with caudal extradural block were recruited. Anesthesia was induced using face mask with sevoflurane 5% in oxygen. After applying standard monitoring, receiving atropine (0.02 mg/kg IV) and atracurium (0.5mg/kg IV), intubation with a suitable endotracheal tube was done. Anesthesia was maintained using isoflurane and top up doses of atracurium 0.1 mg/kg every 20 minutes with 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 CK Group (n=20): Received caudal solution of total amount of 1ml/kg containing bupivacaine 0.25% plus ketamine 0.5mg/kg in saline.Intraoperative hemodynamic (heart rate and blood pressure) were observed with the need for intraoperative fentanyl analgesia (1mg/kg). Also postoperative hemodynamics (heart rate, blood pressure and SpO2) were observed with assessment of analgesia, CHIPP score, duration of motor block sedation, and development of any side effects until 2h postoperative.Results: Intra and postoperative hemodynamics showed lower and more stable readings in CK group compared to CB group starting at 80 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 CK group (p=0.0005). Postoperative CHIPP Score showed significantly lower readings in the CK group compared to CB group (p=0.01) throughout the postoperative period. Duration of analgesia was significantly longer in the CK group (8.95±1.43) compared to CB group (4.725±3.05)(p=0.001). Duration of motor block, sedation score, postoperative side effects (urine retention, nausea and vomiting, pruritis and respiratory depression) showed no statistical significant difference between the two groups.Conclusion: Ketamine 0.5mg/kg added 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 surgeries lasting 90-120min. to be done with single shot caudal analgesia.