Comparison of Spinal Anaesthesia with Bupivacaine and Fentanyl vs Bupivacaine and Clonidine in Lower Limb Surgeries

Background: Spinal anaesthesia is very popular in lower limb surgeries because it is effective and safe. Bupivacaine is widely used, however due to its short duration of postoperative analgesia fentanyl and clonidine are used to increase the efficacy. Aim: To determine the effectiveness and safety of intrathecal bupivacaine with fentanyl to that of bupivacaine with clonidine during lower limb surgeries. Methodology: It was a prospective, randomized, double-blinded clinical study conducted on 80 ASA I–II patients undergoing elective lower limb surgeries. Group F received 2.5 ml of 0.5% hyperbaric bupivacaine with 25 µg fentanyl intrathecally, while Group C received 2.5 ml of 0.5% hyperbaric bupivacaine with 50 µg clonidine intrathecally. Sensory and motor block characteristics, duration of analgesia, sedation levels, and side effects were observed and statistically analyzed. Results: The onset of sensory and motor blocks was similar in both groups. However, the duration of sensory block (225.75 ± 28.55 min vs. 180.40 ± 22.65 min), motor block (210.45 ± 24.60 min vs. 160.85 ± 21.20 min), and analgesia (320.75 ± 34.85 min vs. 250.35 ± 31.25 min) were significantly longer in the clonidine group (p < 0.001). Side effects were minimal and comparable. Conclusion: Both adjuvants are effective, but clonidine provides longer sensory, motor, and analgesic duration with mild sedation and stable hemodynamics, making it a superior alternative to fentanyl.