Randomized clinical study comparing safety and efficacy of adjuvant intrathecal clonidine versus normal saline along with bupivacaine anaesthesia in lower limb surgery patients

Abstract

Background: Various adjuvants have been used in intrathecal anesthesia to avoid intraoperative visceral and somatic pain and prolong postoperative analgesia. Clonidine, partially selective α2-agonist, is being evaluated as a neuraxial adjuvant with intrathecal bupivacaine. The objective of the study was to evaluate and compare safety and efficacy of intrathecal clonidine as adjuvant to bupivacaine with control normal saline.Methods: American Society of Anesthesiologist grade 1 and 2 patients (60 patients) were randomly divided into two groups of 30 patients each for lower limb surgeries. Study group injected with intrathecal 3ml of 0.5% Bupivacaine heavy (15mg) + 1µg/kg of clonidine and control group injected with 3ml of 0.5% Bupivacaine heavy (15mg) + equivalent dose of normal saline. The onset and duration of sensory and motor block, duration of analgesia, and the incidence of side effects in both groups were observed and compared.Results: Time for 2 segment regressions in study group was 186.17±25.92 minutes compared to control was 103.20±19.15 minutes (p value<0.001). Total duration of analgesia in control was 226.50±35.69 minutes and in the study group was 465.67±100.37 minutes (p value<0.001). The average duration of motor block in control group was 181.17±26.12 minutes compared to study group was 217.80±41.51 minutes (p value<0.001). The small dose of intrathecal clonidine is not significantly associated with systemic side effects such as bradycardia and hypotension.Conclusions: Clonidine added to bupivacaine for intrathecal anesthesia effectively increases the duration of sensory block, duration of motor block and duration of analgesia and does not produce any significant hemodynamic changes. No significant side effects are associated with it.