A comparison of ropivacaine, ropivacaine with tramadol and ropivacaine with midazolam for post-operative caudal epidural analgesia.

BACKGROUND AND AIMS: Caudal epidural analgesia is the most commonly used method of post-operative analgesia in children undergoing subumbilical surgeries. Many additive drugs have been used to prolong the post-operative analgesia. The aim of this study was to compare the efficacy of tramadol or midazolam addition to caudal ropivacaine for post-operative analgesia in children undergoing subumbilical surgeries.

METHODS: In this prospective, randomised, double-blinded comparative study, sixty children of either gender, in the age group of 1-5 years and scheduled for elective subumbilical surgeries were randomly divided into three groups of twenty each. Children in Group R received an epidural injection of 1 mL/kg of 0.2% plain ropivacaine whereas children in Group RT received an epidural injection of 2 mg/kg of tramadol plus 1 mL/kg of 0.2% ropivacaine and Group RM received an epidural injection of 50 μg/kg midazolam plus 1 mL/kg of 0.2% ropivacaine. The primary outcome variable was the duration of time to rescue analgesia. The secondary outcome variables were motor block, sedation score and urinary retention. Statistical comparison among the three groups was performed using one-way ANOVA with post hoc analysis using Bonferroni. For qualitative variables, Chi-square test was used. Statistical significance was defined as P < 0.05.

RESULTS: The mean duration of time to rescue analgesia was significantly longer ( P < 0.001) in Group RT (913 ± 315.5 min) and Group RM (769.2 ± 331.9 min) compared to Group R (437.75 ± 75.68 min). However, there was no significant difference in the duration of time to rescue analgesia between RT and RM groups. Motor block and sedation scores were comparable between groups.

CONCLUSIONS: The addition of tramadol or midazolam to caudal epidural ropivacaine prolongs the duration of analgesia without causing significant side effects.