Study of Caudal Ropivacaine With or Without Dexmedetomidine for Postoperative Analgesia in Pediatric Infra-umbilical Surgery: A Double-blinded Randomized Control Trial

Children have significant pain following surgery. It has been under-managed most of the time. Poorly controlled post-operative pain increases the morbidity. It leads to post-operative agitation, urinary retention, nausea and vomiting, hypoxia, pulmonary edema, cardiovascular and temperature instability. So, postoperative pain management is an essential and important component of pediatric postoperative care. Adequate pain control after surgery permits early mobilization, reduces postoperative complication, prevents development of fear and anxiety and allows early hospital discharge.

Caudal block is one of the modality of multimodal analgesia. It is a well-established, effective and relatively safe technique used for intra and post-operative analgesia in children undergoing abdominal and lower limb surgery. It provides excellent analgesia, reduces intra-operative anesthetics drug requirements, ensures pain free recovery from anesthesia, decreases stress response and avoids deleterious adverse effects of narcotic drugs.

However, the main disadvantage of caudal block is being its short duration of action with sole local anesthetics. Even long-acting local anesthetic drugs such as bupivacaine provides only 4-8 hours of analgesia. The insertion of catheter in caudal space to administer repeated doses or continuous infusions of local anesthetic drug is not popular because of concerns of infection. So, various adjuvants like Fentanyl, Morphine, Ketamine, clonidine, Dexmeditomidine etc. have been used to prolong the duration of analgesia.

Morphine and Fentanyl are opioids that have been used traditionally in combination with a local anesthetic to achieve prolonged anesthetic effect. The addition of opioid does provide better analgesia but there is a possibility of an increased incidence of pruritus, urinary retention, nausea, vomiting and respiratory depression. Similarly, Ketamine and Clonidine are the widely preferred adjuvant to caudal block but have their own number of unpleasant adverse effects8.

Hence, there is still ongoing investigations to find for an adjuvant that can safely prolong caudal analgesia. Recently, Dexmedetomidine has been used for this purpose. Various studies have described the use of Dexmedetomidine with local anesthetic drugs in caudal block for the management of postoperative pain in children. Saadawy et al. found that 1μg/kg caudal dexmedetomidine with bupivacaine was associated with an extended duration of postoperative analgesia while in other studies 2μg/kg Dexmedetomidine was used with caudal Bupivacaine or Ropivacaine for providing postoperative analgesia in children undergoing lower abdominal and perineal surgeries.