Comparison of Different Doses of Clonidine as an Adjuvant to Intrathecal Bupivacaine for Spinal Anaesthesia in Patients Undergoing Lower Limb Orthopedic Surgery

Abstract

Background: Clonidine is added to local anaesthetics as adjuvant in spinal anaesthesia to improve quality and duration of sensory and motor block. Dose of Clonidine used is varied from 15μg to 150 μg and most of the studies are with low dose (8mg to 12mg) hyperbaric bupivacaine. Aim: Aim of this study was to evaluate and compare the effects of addition of three different doses of clonidine (15, 30 and 45 μg) to 18 mg hyperbaric bupivacaine in patients undergoing lower limb orthopedic surgery under spinal anaesthesia Study design: Prospective, randomized, double-blind, controlled study. Materials and Methods: 120 patients enrolled in the study were randomly divided into four groups of 30 each. Group I ,II, III,and IV received 0,15,30 and 45μg of clonidine respectively as an adjuvant to 18 mg hyperbaric bupivacaine. The volume of the solution was kept constant to 4 ml by adding normal saline. Results: The mean time for two segment regression, mean duration of sensory and motor block were higher in all the Clonidine groups. Mean arterial pressure was lower and vasopressor requirement was higher with an increase in the dose of Clonidine. Conclusion: To conclude, the addition of 15 μg of clonidine as an adjuvant to hyperbaric bupivacaine for spinal anaesthesia was found to be effective compared to 30 μg of clonidine, 45μg of clonidine as it causes significant prolongation of motor and sensory block duration without causing any hemodynamic derangements.