A dose-response study of caudal dexmedetomidine with ropivacaine in pediatric day care patients undergoing lower abdominal and perineal surgeries: a randomized controlled trial

Objectives This randomized double-blind study was conducted to evaluate the analgesic efficacy and safety of addition of three different doses of dexmedetomidine in caudal ropivacaine compared with plain ropivacaine for postoperative analgesia in pediatric day care patients. Methods Eighty children of American Society of Anesthesiologists grade I-II, aged 1-8years, undergoing lower abdominal and perineal surgery were included. Children were randomly allocated into four groups. Group 1 received 0.2% plain ropivacaine 0.75mlkg(-1), while group 2, 3, and 4 received dexmedetomidine 0.5, 1.0, and 1.5gkg(-1), respectively, along with 0.2% ropivacaine 0.75mlkg(-1). Anesthesia was induced and maintained with sevoflurane and 50% N2O in oxygen. Children were observed for postoperative pain, nausea-vomiting, agitation, sedation, and adverse effects. Rescue analgesia was provided with oral paracetamol. Results Postoperative analgesia was significantly prolonged in all dexmedetomidine groups as compared to plain ropivacaine group (P<0.001). All patients in the plain ropivacaine group required rescue analgesia within first 6 postoperative hours, while none in the other three groups. None of the patients showed delayed anesthetic emergence. Four patients in the plain ropivacaine group developed agitation, while none in the dexmedetomidine groups. Patients receiving dexmedetomidine 1.5gkg(-1) were more sedated as compared to the other groups (P<0.01), but it did not delay discharge of the patients. Conclusions All three doses of caudal dexmedetomidine appear to be effective for preventing postoperative pain in pediatric day care patients. Caudal dexmedetomidine used in these doses seems to be safe for day care surgery.