BACKGROUND: Hyperbaric bupivacaine has been the gold standard drug for the safe conduct of spinal anaesthesia. It offers duration of 1.5 to 2.5 hours of anaesthesia and analgesia, various adjuvants are being used with local anesthetics for prolongation of intraoperative and postoperative analgesia. clonidine, an α 2 adrenergic agonist is new neuraxial adjuvant gaining popularity. AIM: The purpose of this study was to compare the efficacy of sensory and motor block, degree of postoperative analgesia, and adverse effects of clonidine and fentanyl used intrathecally with hyperbaric bupivacaine for spinal anaesthesia. SETTINGS AND DESIGN: the study was conducted in prospective, double blind manner, included 60 ASA class I and II patients undergoing lower limb, lower abdominal, gynaecological and urological surgeries under spinal anaesthesia after approval from hospital ethics committee with written and informed consent of patients. MATERIALS AND METHODS: the patients were randomly allocated into two groups (30 patients each), group C received hyperbaric bupivacaine 15mg with clonidine 1µg. kg-1 and group F received hyperbaric bupivacaine15mg with fentanyl 25µg. This randomized study was conducted to compare the effects with regards to, Onset and duration of block, degree of post-operative analgesia (evaluated by VAS scale) and side effects associated with the drugs were recorded. RESULTS: Patients in group C had significantly longer sensory and motor block times than group F. The mean onset of sensory block in group C was 136.67sec and in group F was 138.33 sec. The mean onset of motor block in group C was 200.00sec and in group F was 206.67 sec. There were no differences with respect to the onset of block .The mean duration of sensory block in group C was 343.67min and in group F was 250.83min. CONCLUSIONS: There were no differences in the onset of sensory and motor blockade. The duration of analgesia, two segment regressions, and recovery of motor blockade were prolonged when clonidine 1µg.kg-1 was used as an additive to intrathecal hyperbaric bupivacaine compared to fentanyl 25µg for spinal anaesthesia, with side effects like bradycardia, hypotension and pruritus which did not require any treatment. Mild sedation was associated with intrathecal administration of clonidine 1µg.kg-1 which did not require any treatment. KEYWORDS: α 2 adrenorecepor agonist, bupivacaine, clonidine, fentanyl, spinal anaesthesia. INTRODUCTION: Hyperbaric bupivacaine has been the gold standard drug for the safe conduct of spinal anaesthesia. 1 It offers duration of 1.5 to 2.5 hours of anaesthesia and analgesia. Discovery of various spinal receptors like α 2-adrenergic, cholinergic, opioid, NMDA, GABA,

Intrathecal clonidine is being extensively evaluated as an alternative to neuraxial opioids for control of pain and has been proven to be a potent analgesic. It is used in combination with opioids and local anaesthetics in labour analgesia and orthopaedic surgery. However, there is still dearth of studies for using intrathecal clonidine for postoperative analgesia in lower abdominal surgeries. Pre anaesthetic check-up was carried out pre operatively with a detailed history, general physical examination and systemic examination. Airway assessment and spinal column examination were done. Majority of patients in the both the groups belonged to the group 26 to 55 years. Samples were age matched. The number of males and females in each group was same (n=30) and samples in both groups were matched with respect to sex. Majority of female patients in the both the groups belonged to the group 160 to 170 cms and males 171 to 175 cms, Samples were height matched.