Background: Neuroedocrine stress response(NESR) to surgery is manifested by increase in circulating catabolic hormones (cortisol) leading to protein catabolism. This can be modified by providing adequate postoperative analgesia in children in the form of caudal block using ropivacaine and non opioid adjuvants like clonidine.There is paucity of literature comparing effects of 3µg/kg and 1.5µg/kg of clonidine with 0.2% ropivacaine in terms of neuroendocrine stress response to surgery in caudal block. Methods: 45 children aged 1­ 8 years, after premedication with oral midazolam and induction of anesthesia, caudal block was performed. Children were randomly allocated into 3 groups. Blood samples were obtained just after induction of anesthesia, 30 minutes after the start of surgery and 60 minutes after the end of surgery for measurement of serum levels of glucose and cortisol. Results: Mean blood glucose were within normal range and there was no statistically significant difference between the groups. There was a significant rise in serum cortisol levels from baseline values (T0) in group R in the post operative period. There was statistically significant fall from baseline levels in cortisol values postoperatively in the clonidine 1.5 µg/kg group(RC1.5) and clonidine 3µg/kg group (RC3) and this fall in cortisol values was greater in the clonidine 3µg/kg group when compared to the clonidine 1.5 µg/kg group. Conclusions: There was blunting of NESR to surgery when clonidine was used as adjuvant to ropivacaine in caudal block and this was maximum with clonidine dosage of 3µg/kg. 

Keywords: Neuroendocrine Stress Response; Clonidine; Ropivacaine; Caudal Block.