Intra-articular Versus Intravenous Dexmedetomidine in Arthroscopic Knee Surgeries Under Local Anesthesia

Patients will receive an intra-articular mixture of 19 ml bupivacaine 0.5% with epinephrine 1:200.000 added to 1ml (1 µg/kg) of dexmedetomidine (total volume 20 ml), and i.v. saline 20 ml infused over 10 min starting with local anesthesia

Patients will be injected intra-articularly with mixture of 19 ml 0.5% bupivacaine with epinephrine 1:200.000 and 1 ml of isotonic saline (total volume 20 ml), in addition to i.v. 20 ml saline containing 1 µg/kg dexmedetomidine over 10 min infusion starting with local anesthesia.