Background: The aim of the study was to assess the efficacy of clonidine when associated to fentanyl as additives to bupivacaine 0.25% given via single shot caudal epidural in pediatric patients for postoperative pain relief.
Materials and Methods: In the present prospective randomized double blind study, 80 children of ASA-I class aged from 1 to 5 years scheduled for sub-umbilical surgical procedures were randomly allocated to two groups: 
-	group I received caudal block with : bupivacaine 0.25% (1 ml/kg) with fentanyl 1 μg/kg and clonidine 1μg/kg in 
-	group II received caudal block with : bupivacaine 0.25% (1 ml/kg) with fentanyl 1 μg/kg and placebo (normal saline) 
Postoperatively patients were assessed for analgesia and side effects.
Results:  Demographic parameters (age, weight, size, sex) and per operative heart rate and blood pressure were similar in both groups. Significantly high levels and prolonged duration of post-operative analgesia was observed from the 6th to the 24th post operative hours in group I (P<0.0001) with increased incidence of post operative motor blockade (p=0.044). 
Conclusions:
The adjunction of clonidine to fentanyl as additives to bupivacaine 0.25% in single shot caudal epidural in children may improve and prolongs post operative analgesia for   sub-umblical surgical procedures.

Caudal clonidine for pain relief in children undergoing sub-umbilical surgery: a randomized prospective trial