The values of EC50 and EC95 ( 95 % CI ) of caudal levobupivacaine from logistic regression analysis were 0.094 ( 0.083-0 .105 ) % and 0.129 ( 0.1-0 .159 ) % , 0.058 ( 0.044-0 .072 ) % and 0.106 ( 0.067-0 .144 ) % , and 0.046 ( 0.033-0 .059 ) % and 0.091 ( 0.055-0 .127 ) % in Groups L , LD1 , and LD2 , respectively .