Randomized controlled trial comparing morphine or clonidine with bupivacaine for caudal analgesia in children undergoing upper abdominal surgery

Caudal clonidine 2 µg kg−1 in bupivacaine 0.2% provides a longer duration of analgesia and sedation compared with caudal morphine 30 µg kg−1 in bupivacaine 0.2% without significant side-effects in children undergoing upper abdominal surgery.