Dexmedetomidine vs. fentanyl as adjuvants to hyperbaric bupivacaine for unilateral spinal anesthesia in lower limb orthopedic surgeries: a randomized trial

Abstract

Background & Objective: Opioids and α2 adrenergic receptor agonists are commonly used as adjuvants to intrathecal local anesthetics to improve the quality and duration of spinal anesthesia (SA). Fentanyl and dexmedetomidine (DEX) are the most commonly used opioid and α2 agonist respectively. We compared the efficacy of these two when used as adjuvants to hyperbaric bupivacaine for SA for lower limb surgeries.
 Methods: A total of 54 patients were randomly assigned to receive unilateral spinal anesthesia with bupivacaine 2.5 ml. Group F (n = 27) received 25 μg fentanyl, and Group D received 10 μg DEX added to the spinal bupivacaine. Time to first analgesic request was the primary outcome, while sensory and motor block characteristics, nalbuphine consumption as rescue analgesic, pain scores, side effects and sedation levels were the secondary outcomes.
 Results: Patients receiving dexmedetomidine as an adjuvant to hyperbaric bupivacaine for spinal anesthesia for lower limb surgeries had a significantly longer time to rescue analgesia than those receiving fentanyl. The mean time to rescue analgesia in Group D was 409.63 ± 74.60 min vs. 295.93 ± 36.72 min (P = 0.000) in the Group F. Also, patients in Group D had significantly longer sensory and motor blocks.
 Conclusion: Intrathecal dexmedetomidine 10 μg seems to be a good alternative to fentanyl 25 μg when used as an adjuvant in unilateral spinal anesthesia for lower limb orthopedic surgeries with better quality postoperative analgesia and with minimal side effects.
 Abbreviations: DEX - Dexmedetomidine; NYHA - New York Heart Association; BMI - Body mass index; MBP - Mean blood pressure; SBP- Systolic blood pressure; DBP- Diastolic blood pressure; VAS - Visual Analog Scale
 Key words: Dexmedetomidine; Fentanyl; Bupivacaine; Anesthesia, Spinal
 Citation: Ghaly SI, Shafik AM, AlTaher WAMM, Motawashleh MG, Alansary AM. Dexmedetomidine vs. fentanyl as adjuvants to hyperbaric bupivacaine for unilateral spinal anesthesia in lower limb orthopedic surgeries: a randomized trial. Anaesth. pain intensive care 2023;27(4):456−463. DOI: 10.35975/apic.v27i4.2191
 Received: March 30, 2023; Reviewed: April 22, 2023; Accepted: April 22, 2023