ABSTRACT
BACKGROUND: The aim of this study was to compare bupivacaine 0.25% and ropivacaine 0.2%, singly and in combination with ketamine, for caudal administration in children. Duration of analgesia, the need for other analgesics and the stress response were measured. METHODS: Eighty children were randomized into four groups of twenty. The bupivacaine group received bupivacaine 0.25% and the ketamine/bupivacaine group received bupivacaine 0.25% plus 0.5 mg/kg ketamine. The ropivacaine group received ropivacaine 0.2%, and the ketamine/ropivacaine group received ropivacaine 0.2% plus 0.5 mg/kg ketamine. The duration of analgesia and analgesic requirements were recorded for each group, as were peri-operative and post-operative concentrations of the stress hormones insulin, glucose and cortisol. RESULTS: Ketamine, added to either bupivacaine or ropivacaine for caudal analgesia, gave a longer duration of analgesia (P < 0.05) than bupivacaine or ropivacaine alone. In all groups, blood insulin concentration was increased, and cortisol concentration reduced. Glucose concentration was significantly increased in all groups (P < 0.05). CONCLUSIONS: Ketamine can safely be added to ropivacaine 0.2% or bupivacaine 0.25% for caudal anesthesia in order to prolong duration of analgesia and reduce the need for additional analgesics. Stress hormone levels are partially attenuated.