Background: In the present day practice of Anesthesiology, bupivacaine is the most commonly used drug for spinal anesthesia. To improve the quality of analgesia and prolong the duration of its action, many adjuvants have been tried. Intrathecal clonidine an α2 adrenoceptor agonist has potent central antinociceptive properties with analgesic effect at spinal level mediated by post synaptically situated adrenoreceptor in dorsal horn of spinal cord .Low doses of clonidine have shown effectiveness in intensifying spinal anesthesia. This study was done to evaluate the efficacy of spinal anesthesia with clonidine added to hyperbaric bupivacaine in lower abdominal surgeries.

Aim: This study compared 0.5% Bupivacaine and 0.5% Bupivacaine with Clonidine for surgeries below the level of umbilicus under spinal anaesthesia.

Materials and Methods: A randomized prospective observational study includes 60 patients of ASA I and ASA II aged 18-60 years, scheduled for elective lower abdominal surgery under spinal anaesthesia. Patients were randomly allocated into two groups. Group B received hyperbaric bupivacaine hydrochloride 12.5mg (2.5mL) + 0.5ml of normal saline. Group BC received bupivacaine hydrochloride 12.5 mg (2.5mL) + 0.5ml (25 μg) of preservative free clonidine .The volumes of both the groups are same (i.e 3.5 ml ). Heart rate, NIBP, SpO2 were monitored. The onset and duration of sensory block and motor block, the highest dermatomal level of sensory block, time to complete motor block recovery and duration of spinal anaesthesia, duration of analgesia and side effects were recorded.

Results: The onset of sensory and motor blockade was faster in the BC group compared to group B. The duration of sensory and motor block were prolonged in group BC compared to group B. Decrease in the systolic blood pressure was noted in group BC. No significant hemodynamic changes were observed in both the groups.

Conclusion: Clonidine potentiates bupivacaine spinal anesthesia by increasing the duration and improving the quality of analgesia without significant hemodynamic side effects.

Keywords: spinal anesthesia, clonidine, bupivacaine

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Dr Konduru Sindhura

Post graduate, Department of Anaesthesiology GEMS