Dexmedetomidine Versus Neostigmine in Addition to Bupivacaine for Caudal Analgesia in Pediatrics Undergoing Congenital Inguinal Hernia Repair

Abstract
Background: Post-operative pain management in children is a necessity for both medical and ethical reasons. Caudal block is one of the oldest and the most popular regional block in pediatric anesthesia. Dexmedetomidine is a specific a2 adrenergic receptor agonist with sedative, anxiolytic, and analgesic properties. Respiratory depression, sedation and pruritis ascribed to the use of caudal opioids are not encoun-tered with neostigmine.
Aim of Study: Our aim is to compare the effect of dexme-detomidine versus neostigmine in addition to bupivacaine for caudal analgesia in pediatrics undergoing congenital inguinal hernia repair.
Methods and Material: This study was carried out on 90 children, 1-6 years, ASA I-II, scheduled for congenital inguinal hernia repair. Patients were randomly classified into 3 equal groups, 30 patients each, caudal block with a total volume of 0.5ml/kg Group I: Bupivacaine 0.25%, Group II: 0.25% bupivacaine and dexmedetomidine 2mg/kg and Group III: 0.25% bupivacaine with neostigmine 2mg/kg in. HR, MAP and SpO2 were recorded at baseline & 15 (5 minutes after caudal), 25, 35, 45, 60min after induction of anesthesia & 5, 30, 60 & 120min after recovery. Pain score was recorded at 1, 2, 4, 6, 24hr after recovery using the FLACC Behavioral Scale, number of patients who needed rescue analgesia in the 1st 24hr' post-operative. Rescue analgesia was administered at FLACC score £4, total amount of acetaminophen within the 1st 24h, time till administration of first rescue analgesia & any undesirable side effects.
Results: HR and MAP were statistically non-significant difference in the three groups, but it was statistically significant difference between the pre-operative HR and MAP and at 25min. FLACC behavioral pain score & total does of analgesia was significantly lower in group II than in group III than in group I. The time of first rescue analgesia was earlier in group I than in group III than in group II.
Conclusions: Addition of dexmedetomidine or neostigmine to bupivacaine in a dose of 2mg/kg results in superior analgesia than bupivacaine alone. But dexmedetomidine had better analgesic effect than addition of neostigmine to bupivacaine.