Clonidine as an adjuvant for bupivacaine in caudal analgesia for sub-umbilical surgery: A prospective randomized double blind study

Abstract

Background & Objectives: Caudal analgesia is an accepted and popular method of providing intra and
postoperative analgesia for abdominal, perineal and lower limb surgeries in children. Caudal epidural
block with bupivacaine is one of the most common regional anesthetic technique used in children. Several
adjuncts such as opioids, ketamine, midazolam and neostigmine have been used with bupivacaine to
prolong its action and thus extend the duration of postoperative analgesia provided by ‘single shot’ caudal
technique. Clonidine, an α2 agonist has extensively been used in neuraxial blocks and peripheral nerve
blocks to prolong the action of bupivacaine without significant respiratory depression after systemic,
epidural and spinal administration. Hence, this study was conducted to know the efficacy and safety of
clonidine as an adjuvant to bupivacaine in single shot caudal block in children.
Methodology: This study was conducted among 60 children in the age group of 1-12 years coming for
various elective sub-umbilical surgeries. They were divided into two groups of 30 each. Group A received
caudal 0.25% bupivacaine plain with 0.5 ml Normal saline and Group B received caudal 0.25% bupivacaine
1 ml/Kg with clonidine 1 μg/Kg as an adjuvant made to 0.5 ml with normal saline. The various parameters
studied were intraoperative hemodynamic changes, onset of action, duration of postoperative analgesia,
postoperative analgesic requirement, duration of postoperative sedation and incidence of side effects.
Pain and sedation assessment was done at 0, 1, 2, 3, 4, 8, 12, 16, 20 and 24 hour after surgery.
Results: The groups were similar in age, sex and weight. The hemodynamic parameters like heart rate
(HR), mean arterial pressure (MAP), oxygen saturation (SpO2) were also similar between the two groups
before and after administering caudal block. The mean duration of analgesia in group B (506.67 ± 43.81
min) was significantly longer (p < 0.001) than in group A (270.67 ± 43.70 min). The pain score in the
two groups were similar upto 3 hrs but was higher in Group A as compared to Group B. The duration of
sedation is significant for upto 4 hrs in Group B than Group A. The number of rescue analgesics used was
significantly more in Group A as compared to Group B. Incidence of bradycardia, hypotension, vomiting
were not significant in both the groups.
Conclusion: This study showed that the addition of clonidine in the dose of 1 μg/kg to 0.25% bupivacaine
plain 1 ml/kg prolonged the duration of analgesia with better sedation in children with less post operative
analgesic requirement after a single shot caudal block with minimal side effects in children.