Caudal neostigmine, bupivacaine, and their combination for postoperative pain management after hypospadias surgery in children

Abstract

In a randomized, double-blinded study, we examined the analgesic efficacy of caudal neostigmine, bupivacaine, or a mixture of both drugs in 60 children. After the induction of general anesthesia, children were allocated randomly into three groups (n = 20) to receive a caudal injection of either 0.25% bupivacaine 1 mL/kg, with or without neostigmine 2 micro g/kg, or neostigmine 2 micro g/kg in normal saline 1 mL/kg. Intraoperatively, children receiving caudal bupivacaine or a bupivacaine/neostigmine mixture maintained hemodynamic stability, required less inhaled anesthetics, and had a shorter recovery time compared with the caudal neostigmine alone. Postoperatively, the caudal bupivacaine/neostigmine mixture resulted in superior analgesia compared with the other two groups. Recovery to first rescue analgesic times were (mean +/- SD) 22.8 +/- 2.9 h, 8.1 +/- 5.9 h, and 5.2 +/- 2.1 h in the bupivacaine/neostigmine, bupivacaine, and neostigmine groups, respectively (P < 0.001). In addition, the bupivacaine and neostigmine groups received more doses of paracetamol than the bupivacaine/neostigmine group to maintain adequate analgesia in the first 24 postoperative h. Postoperative vomiting occurred in 25%, 10%, and 30% in the caudal bupivacaine/neostigmine, bupivacaine, and neostigmine groups, respectively (P < 0.01). We conclude that caudal neostigmine 2 micro g/kg provides postoperative analgesia comparable to caudal bupivacaine in children undergoing hypospadias repair surgery.

Implications: Caudal neostigmine 2 micro g/kg provides postoperative analgesia comparable to caudal bupivacaine in children undergoing hypospadias repair surgery. Co-administration of the two drugs is associated with extended postoperative analgesia and reduced need for supplementary analgesics.