Background: Poorly controlled acute pain after shoulder surgery is associated with a variety of unwanted post-operative
consequences, including patient suffering, prolonged hospital stays and an increased likelihood of chronic pain. The interscalene block is the gold standard for shoulder anesthesia and the most commonly used block for shoulder procedures. Aim of the work: to compare the effects of adding either 100 micro-grams of dexmedetomidine or 50 micro-grams of fentanyl to bupivacaine in ultrasound-guided interscalene nerve block, as regards the onset and the duration of the sensory and motor block, and the duration of post-operative analgesia. Patients &Methods:75 patients of either sex, ASA physical status (I, II) scheduled for elective arthroscopic surgeries of shoulder under ultrasound guided interscalene brachial plexus block at Ain Shams University Hospitals who were randomly divided into 3 equal groups; Group C: 25 patients received a total volume of 30 ml bupivacaine 0.5%. Group D: 25 patients received a total volume of 30 ml
bupivacaine 0.5% added to 100 micrograms of dexmedetomidine, Group F: 25 patients received a total volume of 30 ml bupivacaine 0.5% added to 50 micrograms of fentanyl. Results: This study showed that addition of a 100 micro gram of
dexmedetomidine to bupivacaine in interscalene nerve block shortens the onset times of sensory and motor block and prolongs their duration in comparison to 50 micro-gram of fentanyl when added to bupivacaine, and to bupivacaine when used alone, also dexmedetomidine got and added effect of conscious sedation with minimal side effect. Conclusions: Our study showed that addition of dexmedetomidine to bupivacaine in interscalene nerve block shortened the onset times of
both sensory and motor blocks and prolonged their durations. This occurred in comparison to fentanyl when added to bupivacaine and to bupivacaine when used alone.