Comparative Study Between Dexmedetomidine And Fentanyl As An Adjuvant To Bupivacaine In Ultrasound-guided Interscalene Brachial Plexus Block in Arthroscopic Shoulder Surgeries

Abstract

Background: Poorly controlled acute pain after surgery is associated with a variety of unwanted post-operative consequences, including patient suffering, distress, myocardial ischemia, prolonged hospital stay and an increased likelihood of chronic pain. Brachial plexus is a complex network of nerves supplying the whole upper limb including its motor and sensory supply. Arising from the neck, passing through the axilla to the upper limb. It is composed of 5 roots, 3 trunks, 6 divisions, 3 cords, and terminal branches. Aim of the work: The aim of this study was to compare the effects of adding either 100 micro-gram of dexmedetomidine or 50 micro-gram 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, sedative effect and their effect on reduction of the post-operative analgesic requirement, as well as monitoring the occurrence of any complication. Patients & Methods: In our study, 75 patients were randomly divided into 3 equal groups; Group C (control group): 25 patients received a total volume of 30 ml bupivacaine 0.5%. Group D (Dexmedetomidine group): 25 patients received a total volume of 30 ml bupivacaine 0.5% added to 100 micrograms of dexmedetomidine (1 ml of commercially available drug form), Group F (Fentanyl group): 25 patients received a total volume of 30 ml bupivacaine 0.5% added to 50 micrograms of fentanyl.(29 bupivacaine 0.5% and 1 ml of fentanyl). Results: This study showed that addition of a 100 micro gram of dexmedetomidine to bupivacaine in ultrasound guided interscalene nerve block shortens the onset times of sensory block and motor block and significantly prolongs their duration and decreases the amount of total post-operative analgesic requirements in comparison to 50 micro-gram of fentanyl when added to the same volume and concentration of bupivacaine that fasten the onset of sensory and motor block and also prolongs the duration of the sensory and motor block in comparison to group C (bupivacaine only), but lesser than group D (dexmedetomidine group), also dexmedetomidine got and added effect of conscious sedation with minimal side effect making it more superior to fentanyl in the previously used doses. Conclusions: In the current study, it was obvious that: Addition of dexmedetomidine to bupivacaine in interscalene nerve block shortened the onset times of both sensory and motor blocks and significantly prolonged their durations. This occurred in comparison to fentanyl when added to bupivacaine and to bupivacaine when used alone. Dexmedetomidine had also the added effect of sedation with minimal side effects, which makes it more superior to fentanyl as an adjuvant to local anesthetics in peripheral nerve blocks. Addition of dexmedetomidine to bupivacaine