A PROSPECTIVE RANDOMIZED COMPARATIVE STUDY OF CLONIDINE VERSUS FENTANYL AS ADJUVANTS TO EPIDURAL BUPIVACAINE IN PATIENTS UNDERGOING ELECTIVE LOWER LIMB SURGERIES

Abstract

Background: Epidural adjuvants improve the quality and duration of analgesia while reducing the dose requirement of local anaesthetics. Clonidine and fentanyl are commonly used epidural adjuvants, but their comparative efficacy remains a subject of interest. This study aims to compare the effects of clonidine and fentanyl as adjuvants to epidural bupivacaine in patients undergoing elective lower limb surgeries. Materials and Methods: This prospective, randomized comparative study was conducted over 18 months and included 60 ASA physical status I and II patients aged 18–60 years undergoing elective lower limb surgeries. Patients were randomly allocated into two groups (n = 30 each). Group BC received 16 mL of 0.5% isobaric bupivacaine with clonidine (1 μg/kg), while Group BF received 16 mL of 0.5% isobaric bupivacaine with fentanyl (0.5 μg/kg). The primary outcomes included onset and duration of sensory and motor block, and secondary outcomes included time to two-segment regression, duration of postoperative analgesia, haemodynamic parameters, sedation score, and adverse effects. Results: Group BF demonstrated a significantly faster onset of sensory block (6.3 ± 0.79 vs. 11.5 ± 0.82 minutes) and motor block (16.9 ± 1.32 vs. 24.2 ± 1.10 minutes) compared with Group BC (p < 0.001). However, Group BC showed significantly prolonged two-segment regression time (268.2 ± 0.38 vs. 109.2 ± 0.27 minutes), duration of sensory block (307.8 ± 0.47 vs. 147.0 ± 0.34 minutes), duration of motor block (292.8 ± 0.42 vs. 133.8 ± 0.35 minutes), and time to first rescue analgesia (307.8 ± 0.47 vs. 207.6 ± 0.34 minutes) (p < 0.001 for all comparisons). The incidence of adverse effects, including hypotension, bradycardia, and nausea/vomiting, was comparable between the two groups (p = 1.000). Conclusion: Epidural clonidine (1 μg/kg) as an adjuvant to bupivacaine provided significantly prolonged sensory and motor blockade and longer postoperative analgesia than epidural fentanyl (0.5 μg/kg), without increasing adverse effects. Therefore, clonidine may be considered an effective and safe alternative to fentanyl for epidural anaesthesia in elective lower limb surgeries.