Efficacy of caudal fentanyl and ketamine on post-operative pain and neuroendocrine stress response in children undergoing infraumbilical and perineal surgery: A pilot study

BACKGROUND AND AIMS: It is well-known that neuroendocrine stress response (NESR) occurs in children and it can be modified by caudal block. However, there is paucity of literature comparing caudal fentanyl and ketamine on NESR. The present study was aimed to compare the analgesic efficacy of these caudal adjuvants and their effect on (NESR) in children undergoing infraumbilical and perineal surgery. MATERIALS AND METHODS: A total of 60 children undergoing infraumbilical surgery were included in this randomized, double-blind study. Three groups of 20 each were assigned to receive caudal block with bupivacaine 0.25% 1 ml/kg along with either 0.9% normal saline (Group I) 1 μg/kg fentanyl (Group II) or 0.5 mg/kg ketamine (Group III). Modified visual analogue scale (VAS) was used for assessment of post-operative pain, and stress response was assessed by blood glucose, serum cortisol and insulin levels at various time intervals RESULTS: VAS scores were significantly lower in the ketamine group at all-time intervals upto 4 h (P < 0.05). Patients in ketamine group required rescue analgesia significantly later (8.23 h) when compared to fentanyl (5.95 h) and bupivacaine group (4.10 h). Caudal block led to significant decrease in cortisol and insulin levels within the groups however this significance was not achieved between groups. CONCLUSION: Caudal ketamine in a dose of 0.5 mg/kg provides prolonged analgesia when compared to fentanyl 1 μg/kg. Blunting of the NESR was observed in all the groups though the indicators of the response were lowest with ketamine.