Background: An effective pain therapy to block or modify the physiologic responses to stress has become an essential component of anesthesia for adequate postoperative pain relief.
Objective: This work is aimed to evaluate effect of adding magnesium sulfate to long acting local anesthetic as bupivacaine on  ultra sound  guided inter scalene nerve block undergoing elective upper limb surgery.
Patients and Methods: 60 Adult patients were included study and randomized into two equal groups; Magnesium Group received bupivacaine plus magnesium sulfate, and Saline Group received bupivacaine plus normal saline 2 ml. [The demographic data (age, sex, height, weight and ASA scoring) showed no statistical significance between 2 groups]. The time taken to stimulate the brachial plexus and the onset of block were recorded. The regain of sensation and motor power were checked at regular intervals. Patient and surgeon satisfaction were questioned. The study was conducted in Al-Azhar University Hospitals (Al-Hussein and Bab-Shaarya), from December 2019 till June 2020.
Results: The duration of sensory and motor block, magnesium group was statistically significant compared to saline group [Mean and (standard deviation 789(135), 788(120) minvs710 (150), 720 (135) min, P= 0.038 vs. 0.042 respectively]. Patient satisfaction was statistically significant in favor to the magnesium group. On the other hand, there was no significant difference in surgeon satisfaction between both groups.
Conclusion: The addition of magnesium sulfate to a bupivacaine for interscalene nerve block prolongs the duration of analgesia and reduces postoperative pain.