The Value of Adding Either Meperdine or Fentanyl to Clonidine-bupivacaine

The use of clonidine as an alternative to epidural opioids offers several potential benefits. Clonidine does not have respiratory depressant effects, and the incidence of vomiting and pruritus is less frequent compared with that seen after administration of epidural morphine. Epidural clonidine have focused on the optimal doses of clonidine to be used, rather than analyzing the potential advantage of using epidural clonidine versus opioids with respect to efficacy and incidence of side effects. Epidural fentanyl has been used effectively as an alternative to morphine and has been shown to induce fewer complications when compared with epidural morphine. However, the incidence of vomiting in patients receiving epidural fentanyl still ranges between 28% and 52% depending on the study population and concentration used. The analgesic and side effects profile of epidural clonidine compared with epidural fentanyl are unknown. The primary aim of this randomized double-blind trial is to test the hypothesis that epidural clonidine decreases the incidence of side effects compared with epidural fentanyl. Therefore, we compared the hemodynamic effects of the epidural bupivacaine-clonidine- fentanyl combination with those of epidural bupivacaine- clonidine- meperdine. The secondary aim of this study was to determine the analgesic efficacy of bupivacaine-clonidine- fentanyl combination in comparison to bupivacaine- clonidine- meperdine combination.