Comparative study between caudal bupivacaine and caudal midazolam for post-operative analgesia in paediatric patients

Abstract

Introduction: Caudal epidural block is the most commonly used regional technique for post-operative analgesia in children. Because of the side effects of bupivacaine which include motor weakness, urinary retention and cardiovascular and central nervous system toxicity, this study was conducted to evaluate the use of epidural midazolam as an alternative analgesic to bupivacaine for children undergoing inguinal hernoitomy Methods: After prior permission from the Institutional Ethical Committee, 60 boys, aged 1-10 years, posted for unilateral inguinal herniotomy were selected. The patients were allocated randomly into two groups (n=25) to receive caudal injection of either 0.25% Bupivacaine 1 ml/kg (group B) or Midazolam 50 microg/kg with normal saline 1 ml/kg (group M). In the post operative period heart rate, blood pressure, pain score, recovery to first analgesic time, total number of analgesics required in 24 hours and side effects if any were noted and analysed. Results: There were no significant differences in quality of pain relief, postoperative behaviour or analgesic requirements between the Midazolam group and the Bupivacaine group. Recovery to first analgesic time though was longer in the Bupivacaine group (9.65 hr) than Midazolam group (7.32 hr); it was statistically not significant (P= 0.9). Any of the side effects such as motor weakness, urinary retention, and respiratory depression were not observed in both the groups. However in both the groups, few of the patients had post-operative vomiting. Conclusion: We conclude that caudal Midazolam in a dose of 50 microg/kg provides equivalent analgesia to Bupivacaine 0.25%, when administered in a volume of 1 ml/kg for children undergoing unilateral inguinal herniotomy for hernia or high ligation of processus vaginalis for hydrocoele.