A prospective randomized comparative study on the effectiveness of intrathecal dexmedetomidine and fentanyl as adjuvants to 0.5% hyperbaric bupivacaine in spinal anaesthesia

Background: Improvements in perioperative pain management for lower abdominal operations have been revealed to decrease morbidity, stimulate untimely ambulation, and progress patients’ long-term outcomes. Dexmedetomidine, a selective alpha-2 agonist, has newly been used intrathecally as adjuvant to spinal anesthesia to extend its effectiveness. We compared different adjuvants they are dexmedetomidine and fentanyl added to hyperbaric bupivacaine for spinal anesthesia. The main endpoints were the time of onset and duration of sensory and motor block, Two segment sensory regression time, and duration of analgesia and occurrence of side effects Method: A total of 60 patients, aged 20-45 years old of physical status of ASA grade I,II, assigned to have elective lower limb surgeries under spinal anesthesia were divided into two equally sized groups (Group 1 and Group 2) in a randomized, fashion. The Group 1 was intrathecally administered 15mg hyperbaric bupivacaine with 25μg fentanyl in 0.5ml of normal saline and the group 2 group 15mg bupivacaine with 10μg dexmedetomidine in 0.5ml of normal saline. For each patient, sensory and motor block onset times, and the duration of two segment sensory regression time, sensory, motor blockade and duration of effective postoperative analgesia, were recorded. Results and Conclusion: The time of onset and duration of sensory and motor blockade and the duration of two segment sensory regression time of effective postoperative analgesia was statistically significant in dexmedetomidine (group 2) compared to fentanyl (group 1). The make use of 10μg dexmedetomidine with hyperbaric bupivacaine compared to intrathecal Fentanyl to adjuvant hyperbaric bupivacaine seems to be more efficiently hastens the onset and prolongs the time of sensory and motor blockade. Intraoperatively, there were fewer occurrences of side effects with intrathecal dexmedetomidine when compared to intrathecal fentanyl and reduces the requirement of rescue analgesic in the postoperative period in patients undergoing elective lower limb surgeries.