Effect of Ultra-low Dose Naloxone During Supraclavicular Brachial Plexus Block on Post-operative Opioi

Patients received 20 mL bupivacaine 0.5% plus 100 ng naloxone (1ml) in 2ml saline.(naloxone ampoule 0.4mg will dilute in 400ml of saline then 1ml of it will dilute in 10 ml saline, so each ml will have 100ng naloxone)

Patients will be injected ultrasound guided in their brachial plexus by 20 mL bupivacaine 0.5% plus 3 ml of saline