COMPARISON OF TWO DIFFERENT DOSES OF INTRATHECAL DEXMEDETOMIDINE (5 µG VERSUS 10 µG) AS AN ADJUVANT TO HYPERBARIC BUPIVACAINE FOR SPINAL ANAESTHESIA IN LOWER LIMB ORTHOPAEDIC SURGERIES: A PROSPECTIVE RANDOMIZED DOUBLE-BLIND STUDY

Abstract

Background: Intrathecal dexmedetomidine (Intrathecal Dexmedetomidine) is increasingly used as an adjuvant to hyperbaric bupivacaine (Hyperbaric Bupivacaine) to increase the extent and spinal anaesthesia’s quality. However, the optimal intrathecal dose for elective orthopaedic procedures on the lower limbs remains uncertain. Objective: To compare the safety and efficacy of 5 µg and 10 µg Intrathecal Dexmedetomidine as an adjuvant to 12.5 mg of 0.5% Hyperbaric Bupivacaine in patients undergoing lower limb orthopaedic surgeries. Methods: Sixty patients aged 18–60 years undergoing elective lower limb orthopaedic surgeries were randomized to receive either 5 µg or 10 µg Intrathecal Dexmedetomidine as an adjuvant to Hyperbaric Bupivacaine. Comparisons were made between block properties, postoperative analgesia, hemodynamic parameters, sedation, VAS Score, and adverse events. Results: Group D10 confirmed faster onset of sensory block (3.70 ± 0.50 vs. 4.53 ± 0.38 min) and motor block [5.50 (5.03–5.80) vs. 6.45 (6.20–6.88) min], along with longer sensory block duration (306.37 ± 26.15 vs. 259.07 ± 26.74 min) and motor block duration (259.77 ± 27.15 vs. 224.23 ± 28.08 min), compared with Group D5 (p < 0.001). Group D10 also had a lower VAS score and provided better postoperative analgesia, with acceptable sedation and a comparable incidence of adverse events. Conclusion: Intrathecal dexmedetomidine 10 µg provided superior spinal block characteristics and postoperative analgesia compared with the 5 µg dose while maintaining acceptable haemodynamic stability and a favourable safety profile. Therefore, 10 µg dexmedetomidine may be considered the preferred intrathecal adjuvant to 12.5 mg of 0.5% Hyperbaric Bupivacaine for elective lower limb orthopaedic surgeries.