Comparison of the effect of caudal ropivacaine, ropivacaine-clonidine and ropivacaine-magnesium on postoperative analgesia and stress response in children

ABSTRACT

Caudal analgesia is widely used for various surgical procedures in children. In order to decrease intra and postoperative analgesic requirements after caudal blockade, various additives can be added with local anesthetics. The aim of this study was to compare the efficacy of pre-emptive caudal blockade using ropivacaine 0.25% alone or combined with clonidine, or magnesium sulfate-on stress response and postoperative pain relief in children. We performed a prospective, randomized study on 60 children, aged 4-10 years, undergoing hypospadius surgery. Patients were randomly assigned into three groups to receive either caudal ropivacaine alone [group R], caudal ropivacaine + clonidine [group RC] or caudal ropivacaine + magnesium sulfate [group RM] prior to a standardized sevoflurane anesthetic. Postoperative pain and analgesic requirements, postoperative sedation, catecholamines plasma levels, as well as hemodynamic parameters were compared among the three groups. Group RC had significantly lower objective pain scale [OPS] scores than group R and group RM in the first six postoperative hours. Fewer patients in group RC required postoperative analgesics than in groups R and RM. The time to 1[st] analgesic dose and number of analgesic doses in each group were significantly less in group RC than in groups R and RM. The sedation score was significantly higher only during the first 2 postoperative hours in group RC than groups R and RM. There was a significant decrease in the mean values of plasma epinephrine [E] and norepinephrine [NE] at the end of surgery and 1 hour after recovery compared to pre-block values in all groups. The addition of clonidine to ropivacaine 0.25% significantly increases the duration of caudal analgesia and decreases postoperative analgesic requirements in children. The addition of magnesium to ropivacaine is comparable to the effect of ropivacaine alone. Caudal analgesia resulted in a significant reduction in catecholamine levels