Efficacy of adding nalbuphine to caudal bupivacaine for postoperative analgesia in children undergoing hypospadias repair surgery. Randomized controlled trial

Background: We hypothesized that adding nalbuphine to bupivacaine would prolong the duration of caudal epidural anaesthesia (CEA) in pediatric patients undergoing hypospadias repair surgery. Methods: 60 children scheduled for elective hypospadias surgery under general anesthesia combined with CEA were divided into two equal groups: the control group received caudal bupivacaine 0.25% 1 ml/kg plus 2 ml normal saline. The Nalbuphine group received caudal bupivacaine 0.25% 1 ml/kg plus nalbuphine 0.1 mg/kg in 2 ml normal saline. Intraoperative and postoperative rescue analgesia was managed by giving intravenous paracetamol 15 mg/kg and/or 100mcg nalbuphine. The Face, Legs, Activity, Cry, Consolability (FLACC) pain scale, and the Richmond AgitationSedation Scale (RASS) score were measured. Pre-operative and postoperative blood samples were collected for a subgroup of patients for cortisol analysis. Results: The duration of postoperative analgesia was significantly longer in the nalbuphine group (p < 0.001). The number of patients who needed postoperative supplemental analgesia was significantly lower in the nalbuphine group (p < 0.001). Total paracetamol consumption was significantly higher in the control group (p < 0.001). The FLACC and RASS were significantly lower in the nalbuphine group. Postoperative cortisol levels were lower in the nalbuphine group compared to the control group. Conclusions: Adding caudal nalbuphine 0.1 mg/kg to bupivacaine 0.25% provides better postoperative pain control than bupivacaine alone in children undergoing hypospadias repair.