Comparing midazolam-bupivacaine and neostigminebupivacaine for caudal anesthesia among pediatric patients undergoing herniorrhaphy operations

Introduction: Neostigmine and midazolam are each added to bupivacaine for the purpose of caudal anesthesia. In this study, we compared neostigmine and midazolam, each co-administered with bupivacaine, in terms of analgesia and side effects during pediatric inguinal hernia operations. Materials and methods: We included 60 children 1–6 years old, candidates for elective unilateral herniorrhaphy. After general anesthesia induction with inhaled sevoflurane, a caudal block was performed. Patients were randomly allocated to one of two trial groups: midazolam group received bupivacaine 25% 1ml/kg with midazolam 50μg/kg, and neostigmine group received bupivacaine 25% 1ml/kg with neostigmine 2μg/kg through the caudal route. Heart rate, mean arterial pressure and oxygen saturation were recorded before induction and every five minutes after caudal anesthesia up to 30 minutes. Pain and sedation scores were recorded at 2, 4, 6, 12 and 24 hours after the operation, along with rescue analgesia dosage, vomiting and respiratory depression. Results: Mean duration of analgesia in the midazolam group was similar to the neostigmine group (18.8±9 vs. 20.4±7.5, P=0.44). The analgesic dosage required was not significantly lower in the neostigmine group compared to the midazolam group (58.3±121.7 VS. 70.8±125.8, P=0.63).The number of patients who needed analgesic agents was similar in both groups (P=0.76). Nausea (P 0.05) and vomiting (P=0.01) rates were higher in the neostigmine group. Conclusion: Midazolam (50μg/kg) compared to neostigmine (2μg/kg) provided higher sedation along with lower incidence of postoperative nausea and vomiting.