Efficacy of bupivacaine‐neostigmine and bupivacaine‐tramadol in caudal block in pediatric inguinal herniorrhaphy

Background: Limited duration of analgesia is among the limitations of single caudal injection with local anesthetics. Therefore, the purpose of this study was to evaluate the effectiveness and safety of bupivacaine in combination with either neostigmine or tramadol for caudal block in children undergoing inguinal herniorrhaphy. Methods: In a double‐blinded randomized trial, sixty children undergoing inguinal herniorrhaphy were enrolled to receive a caudal block with either 0.25% bupivacaine (1 ml·kg^?1) with neostigmine (2 μg·kg^?1) (group BN) or tramadol (1 mg·kg^?1) (group BT). Hemodynamic variables, pain and sedation scores, additional analgesic requirements, and side effects were compared between two groups. Results: Duration of analgesia was longer in group BT (17.30 ± 8.24 h) compared with group BN (13.98 ± 10.03 h) (P = 0.03). Total consumption of rescue analgesic was significantly lower in group BT compared with group BN (P = 0.04). There were no significant differences in heart rate, mean arterial pressure, and oxygen saturation between groups. Adverse effects excluding the vomiting were not observed in any patients. Conclusion: In conclusion, tramadol (1 mg·kg^?1) compared with neostigmine (2 μg·kg^?1) might provide both prolonged duration of analgesia and extended time to first analgesic in caudal block.