SUMMARY Background: The aim of this study was to compare the analgesic efficacy and
side effects of preservative free ketamine either alone or in combination with bupivacaine for
caudal blockade in pediatric surgery. Methods: After the induction of standardized general
anesthesia without premedication sixty children, were allocated randomly into 3 groups to
receive single shot caudal blockade by bupivacaine 0.125% 1 ml/kg (group B, n= 20), S-
ketamine (preservative free) 1 mg/kg (group K, n= 20), or a mixture of bupivacaine 0.125% ...