Effect of Different Doses Of Intrathecal Dexmedetomidine In Combination With Bupivacaine On Spinal Anesthesia

This study is designed to assess the efficacy of different doses of dexmedetomidine in combination with intrathecal hyperbaric bupivacaine on spinal anesthesia and its postoperative analgesic characteristics on patients undergoing infra-umbilical procedures. Primary outcome: To ascertain a safe intrathecal dexmedetomidine dose for patients undergoing elective lower abdominal and lower limb surgeries Secondary outcomes: Assessment of level of sedation. Assessment of hemodynamic parameters (Blood Pressure -Heart Rate). Assessment of level of sensory \& motor block. Assessment of pain.