Background: Dexmedetomidine, the new highly selective α2-agonist drug, is now being used as a neuraxial adjuvant. The aim of this study is to evaluate the onset, duration of sensory and motor block, hemodynamic effect, postoperative analgesia, and adverse effects of dexmedetomidine versus fentanyl given intrathecally with hyperbaric 0.5% bupivacaine.

Materials and Methods: After approval from ethical committee, at MNR medical college & hospital, 100 patients of ASA I and II of both sexesaged 18 to 50 years were scheduled for lower abdominal surgerieswere studied. Patients were randomly allocated to receive either 15 mg hyperbaric bupivacaine plus 5 μg dexmedetomidine (group D, n = 50) or 15 mg hyperbaric bupivacaine plus 25 μg fentanyl (group F, n = 50) intrathecal.

Results: Patients in Group (D) had a significantly longer sensory and motor block than patients in Group (F).Time from injection to highest sensory level and onsetof bromage 3 was similar in both groups. Time from injection to T8 sensory level was shorter with group D (p<.001). The regression time of motor block to reach modified Bromage 0 was 419.70±16.85 min in group D and 152.90±8.31 min in group F (P<0.001).

Discussion: In our study Dexmedetomidine 5 μg seems to be an alternative to fentanyl 25 μg as adjuvant to local anaesthetic agent as it provided a good quality of intraoperative and postoperative analgesia with hemodynamic stability.

Conclusions: Intrathecal dexmedetomidine was associated with prolonged motor and sensory block, hemodynamic stability compared to fentanyl.

Keywords: Bupivacaine, dexmedetomidine, fentanyl, spinal anaesthesia