The Effect of Dexmedetomidine versus Tramadol as an Adjuvant in Spinal Anesthesia in Femur Fracture Surgery

Abstract

Background: Femur fracture surgery causes severe postoperative pain and requires prolonged, effective analgesia to support comfort and early mobilization. Spinal anesthesia with hyperbaric bupivacaine gives reliable intraoperative block but a limited duration of analgesia, so intrathecal adjuvants are used to prolong the block. Dexmedetomidine and tramadol are both used as adjuvants, but direct comparative evidence in femur fracture surgery is limited. Objective: To compare dexmedetomidine and tramadol as adjuvants to intrathecal hyperbaric bupivacaine with respect to onset and duration of sensory and motor block, postoperative analgesia, hemodynamics, and adverse effects in femur fracture surgery. Methods: This prospective, randomized, double-blind, two-arm trial enrolled 68 adults (ASA I–II) undergoing elective femur fracture surgery under spinal anesthesia. Group D (n=34) received 5 µg intrathecal dexmedetomidine with 10 mg hyperbaric bupivacaine; Group T (n=34) received 10 mg intrathecal tramadol with the same bupivacaine dose. Block characteristics, time to first rescue analgesia, postoperative VAS pain scores, hemodynamics, sedation, and adverse effects were compared using SPSS v27.0, with p<0.05 considered significant. Results: The groups were comparable at baseline. Dexmedetomidine produced faster onset of sensory (6.6±0.60 vs 7.2±0.83 min; p=0.002) and motor block (9.4±1.12 vs 10.8±1.34 min; p<0.001), longer sensory (246.5±28.4 vs 198.3±24.7 min; p<0.001) and motor block duration (218.7±26.1 vs 172.4±22.8 min; p<0.001), and a longer time to first rescue analgesia (708.2±58.1 vs 474.6±55.4 min; p<0.001). VAS pain scores were lower with dexmedetomidine at 2, 4, and 6 hours (all p<0.001). Bradycardia (17.6% vs 2.9%) and sedation ≥Ramsay 3 (29.4% vs 8.8%) were more frequent with dexmedetomidine, while nausea and vomiting were more frequent with tramadol. No respiratory depression occurred. Conclusion: Intrathecal dexmedetomidine 5 µg gave faster onset, longer block, delayed rescue analgesia, and better early pain control than tramadol 10 mg, at the cost of more bradycardia and sedation. Dexmedetomidine may be preferred when prolonged analgesia is a priority, provided hemodynamics and sedation are monitored.