Epidural caudal block: evaluation of length of analgesia with the association of lidocaine, fentanyl and clonidine.

The association of different substances to local anesthetics aims to improve the blockade quality and prolonging analgesia. The aims of this study were to compare the effectiveness of the association of clonidine, clonidine and fentanyl, and fentanyl, to lidocaine for postoperative analgesia. Participated in this study 64 patients aged 23 years or above, physical status ASA I or II, undergoing to orificial proctologic surgery under epidural caudal anesthesia. Patients were distributed in 4 groups of 16: group I (lidocaine alone); group II (lidocaine and fentanyl); group III (lidocaine, fentanyl and clonidine); and group IV (lidocaine and clonidine). The quality of sensory and motor blockade were compared. There has been no difference in onset and maximum block level among groups. Absence of motor block was the most frequent result, found in about 64% of patients. Analgesia length was different among groups, being more significant in group III. Clonidine, associated or not to fentanyl, has prolonged postoperative analgesia after epidural caudal blockade with lidocaine.