Comparative study of intrathecal dexmedetomidine versus intrathecal fentanyl used as adjuvants to bupivacine 0.5% (hyperbaric) in lower abdominal surgeries done in FEU-NRMF Medical Center from November 2013- December 2013 / Rodolfo Astrologio, Jr., Kristine Marie Ilo-Ramos and Abigail C. Luna.

Includes bibliographical references and appendices

Abstract: Different adjuvants are being used with local anesthetics in spinal anesthesia to avoid intraoperative visceral and somatic pain and to provide prolonged intraoperative and postoperative analgesia. Dexmedetomidine, a highly selective a2-adrenoreceptor agonist, is an approved intravenous sedative and co-analgesic drug which is also a neuraxial adjuvant is gaining popularity. The objective of this study was to evaluate and compare the onset, duration of sensory and motor block, hemodynamic effect, postoperative analgesia and the possible side effects of dexmedetomidine versus fentanyl given intrathecally with hyperbaric 0.5% bupivacaine. The study was conducted in a prospective and double-blinded manner. The study included 60 patients with an American Society of Anesthesiologist (ASA) Physical Status I and II undergoing lower abdominal surgery under spinal anesthesia after approval from the Hospital Ethics Committee with written and informed consent of patients. The patients were randomly allocated into groups (30 patients each). Group A received 3.5 mL volume of 0.5% hyperbaric and 3µg dexmedetomidine in 0.5 mL of normal saline. Group B received 3.5 mL volume of 0.5% hyperberic bupivacaine with 25µg fentanyl. The onset time to reach peak sensory and motor level, regression time of sensory and motor block, hemodynamic changes, side effects and postoperative analgesia were recorded. Patients in Dexmedetomidine Group had significantly longer sensory and motor block times than patients in Fentanyl Group. The regression time of motor block to reach modified Bromage 1, in Dexmedetomidine Group and Fentanyl group, respectively (P< 0.0001). The onset times to reach T6 dermatome and modified Bromage 3 motor block were not significantly different between the groups.Dexmedetomidine group showed significantly less and delayed requirement of rescue analgesic. Intrathecal dexmedetomidine is associated with prolonged motor and sensory block, hemodynamic stability and reduced demand for rescue analgesics in 24 hours compared to fentanyl.

Research - Department of Anesthesiology