. 2020 Oct 15;50(4 Suppl 1):121–141.

Table 1. Intrathecal.

Author (Year)	Groups Studied and Intervention	Results and Findings	Conclusions
Safari, 2016¹⁸	A triple blinded randomized clinical trial with three groups of 28 patients each age 18–60 undergoing abdominal or lower extremity. First group was given 5 μg of dexmedetomidine, 12.5 mg of 0.5% hyperbaric bupivacaine and 0.5 mL normal saline. Second group received 25 μg of fentanyl with 12.5 mg of 0.5% hyperbaric bupivacaine. The control group received only 12.5 mg of 0.5% hyperbaric bupivacaine along with 0.5 mL normal saline.	The dexmedetomidine group sensory block onset was lower compared with other two groups and produced longer block duration for both sensory (P = 0.043, P = 0.016) and motor (P = 0.014). Lower pain scores postoperatively were recorded.	Dexmedetomidine showed to be significantly more effective for sensory and motor blockade onset and duration compared to combined fentanyl and bupivacaine.
Xia, 2018¹⁹	A prospective double-blinded randomized control trial on 90 patients having elective cesarian section. The first group received 5 μg dexmedetomidine with 0.75% hyperbaric bupivacaine. The control group received 0.75% bupivacaine with normal saline.	Results showed there was no difference between both groups for the time of onset for motor block (P > 0.05). Significant difference was found for duration of sensory blockade (P < 0.05) in the dexmedetomidine group.	The use of dexmedetomidine prolonged sensory block requiring less postoperative analgesia with no significant side effects compared to bupivacaine alone.
Abdallah, 2013²⁰	A systematic review and meta-analysis were conducted to examine randomized control trials comparing dexmedetomidine adjuvant compared to local anesthetics alone.	Most studies compared dexmedetomidine to ropivacaine, bupivacaine and levobupivacaine. Results indicated dexmedetomidine prolonged the duration of sensory and motor block (P = 0.00001, P = 0.04) with rapid onset. The time to request from next analgesic was delayed with its use.	Addition of dexmedetomidine significantly prolonged duration of sensory and motor block compared to local anesthetics alone.