A Randomized, Double Blinded Study of Effect of Adding Dexmedetomidine Versus Clonidine to Intrathecal Hyperbaric Bupivacaine on Spinal Block Characteristics in Lower Abdominal Surgeries

Background and objectives: α-2 adrenoreceptor agonists have been used as adjuvants to local anaesthetic agents because of their sedative, analgesic and haemodynamic stabilizing effects and have found to prolong the duration of spinal block following intrathecal administration. This study was done to compare the efficacy of intrathecal dexmedetomidine versus intrathecal clonidine as an adjuvant to 0.5% bupivacaine heavy for spinal anaesthesia. Methods: The study was undertaken under the auspices of Department of Anaesthesiology, Tertiary Hospital, Bangalore. A total of 110 patients, between 20 and 60 years of either sex belonging to ASA grade-I and grade-II were grouped randomly into two groups (n=55). Group 1 (clonidine group) received 12.5 mg of 0.5% hyperbaric bupivacaine with 50 μg clonidine. Group 2 (dexmedetomidine group) received 12.5 mg of 0.5% hyperbaric bupivacaine with 5 μg dexmedetomidine. Descriptive and inferential statistical analysis has been carried out in the present study. Results: Statistically significant differences were found in patients between the groups towards the mean time taken for sensory onset, the mean time taken for attaining the maximum sensory blockade but clinically they were not significant. The mean heart rate showed change at 80th and 90th minutes while the mean SBP is significant during the interval of 10–20 min and 50–90 min between the groups. The mean diastolic blood pressure (DBP) and mean arterial pressure (MAP) showed significant changes at 40th minute and 10th minute, respectively. Conclusion: From our study of 110 patients undergoing lower abdominal surgery under spinal anaesthesia, the addition of dexmedetomidine has some advantages over the addition of clonidine.