Comparison of Clonidine and Fentanyl as an Adjuvant to Intrathecal 0.5% Hyperbaric Bupivacaine in Patients Undergoing Knee Arthroplasty

Abstract

Background and Objective: Fentanyl and clonidine as adjuvants are commonly mixed with 0.5% bupivacaine heavy, by intrathecal route, for prolonging both sensory and motor blockade as well as for enhancing postoperative analgesia in patients undergoing major abdominal or lower limb surgery. This study was undertaken to compare the intraoperative effects and postoperative analgesia of fentanyl and clonidine, used as adjuvant to intrathecal bupivacaine during knee arthroplasty.
 Methodology: This prospective, randomized study was conducted on 60 patients of ASA grade I or II, between 20 and 50 years of age divided into two groups of 30 each. The patients were given 3 ml of 0.5% hyperbaric bupivacaine with either 25 mcg of fentanyl (Group F) or 50 mcg of clonidine (Group C) intrathecally. The onset of sensory and motor block, the duration of blockade, hemodynamic parameters, sedation score, total postoperative analgesia time, and side effects if any were recorded.
 Results: Both the groups were statistically comparable for demographic data, onset of sensory and motor blockade, duration of blockade and hemodynamic parameters. However, the sedation score was more in clonidine group. The duration of analgesia was significantly prolonged in clonidine group when compared with fentanyl group.
 Conclusion: In comparison to fentanyl, addition of clonidine to intrathecal bupivacaine prolongs the duration of postoperative analgesia and cause a higher sedation score.
 Key words: Bupivacaine, clonidine, fentanyl