Methods
ESPB
This randomized controlled double-blind trial recruited 60 cases 18–65 years old of both sexes, American Society of Anesthesiologists (ASA) physical status I-II, scheduled for elective shoulder arthroscopy. Random allocation of 60 cases was done equally into two groups according to the solution injected in US-guided ESPB at T2 before general anesthetic induction. Group (ESPB): 20 ml 0.25% bupivacaine. Group (ESPB + DEX): 19 ml bupivacaine 0.25% + 1 mL dexmedetomidine 0.5 µg/kg. The primary outcome was The total rescue morphine consumption in the first 24 postoperative hours.