Comparison of different doses of clonidine as an adjuvant to intrathecal bupivacaine for spinal anesthesia and postoperative analgesia in patients undergoing caesarian section

Background: The necessity to find out the lowest possible effective dose of clonidine to avoid its known side effects like hypotension, bradycardia and sedation prompted us to design present study. We compared different doses of clonidine as an adjuvant to intrathecal bupivacaine for spinal anesthesia in patients undergoing caesarian section aiming to find out the lowest possible effective dose. Methods: In a prospective, double-blind, randomized controlled study, 60 parturients 18 to 35 years of age, ASA grade I or II, posted for caesarian section were randomly distributed into three equal groups, BC60, BC30 and BC15. Patients were given 2.0 ml of hyperbaric bupivacaine 0.5% with 60 mu g, 30 mu g or 15 mu g of clonidine intrathecally respectively. Hemodynamic parameters, onset, peak and duration of sensory and motor block, level of sedation and duration of postoperative analgesia were compared. Results: All groups were comparable with respect to demographic profile, onset, peak and duration of sensory and motor block and overall hemodynamic stability. We observed dose dependent variability in duration of analgesia and sedation. Duration of analgesia was significantly higher in BC60 group as compared to the other two groups (598.7 +/- 140.47 vs. 436.65 +/- 149.84 and 387.1 +/- 97.05 minutes respectively). Sedation was also more in BC 60 group. Conclusion: Addition of 60 mu g clonidine to intrathecal bupivacaine provides longer duration of postoperative analgesia than 15 mu g or 30 mu g but with more sedation. We get fairly good analgesia with less sedation in 15 mu g and 30 mu g clonidine and are better options when sedation is not desirable.