Comparative Study of two Doses of Intrathecal Dexmedetomidine Versus Fentanyl as Adjuvant to Hyperbaric Bupivacaine Spinal Anesthesia

Abstract

Abstract The aim of this study was to evaluate the effect of addition two different doses of dexmedetomidine or fentanyl to intrathecal hyperbaric bupivacaine on spinal block characteristics, intraoperative hemodynamics, the blood glucose level and postoperative pain. 100 patients ASA I and II, ages 20 -60 years old undergoing elective surgeries below the umbilicus under spinal anesthesia were divided into four groups (n=25 each): Patients were randomly allocated into four equal groups (n= 25, each): Group I: received 3 mL of 0.5% hyperbaric bupivacaine +0.5ml normal saline. Group II: received 3 mL of 0.5% hyperbaric bupivacaine plus 3 μg dexmedetomidine (diluted in 0.5ml of normal saline) intrathecal. Group III: received 3 mL of 0.5% hyperbaric bupivacaine plus 5 μg dexmedetomidine (diluted in 0.5ml of normal saline) intrathecal. Group IV: received 3 mL of 0.5% hyperbaric bupivacaine plus 25 μg fentanyl (0.5ml) intrathecal. intraoperative heart rate and mean arterial blood pressure showed no statistical significant differences between the study groups, patients in group II, III and IV had significantly longer sensory and motor block times than patients in group I. The time of first request of postoperative analgesia was statistically significantly shorter in group I compared to the other groups. Pain scores were higher in group I compared to the other groups. Postoperative blood glucose level was only statistically significantly higher in group II compared to the other groups. Both intrathecal dexmedetomidine and fentanyl are associated with prolongation of sensory and motor block, with stable hemodynamics, minimal effect on blood glucose level, and better postoperative analgesia, compared to intrathecal bupivacaine alone. Key Words: Spinal anesthesia, bupivacaine, dexmedetomidine, fentanyl