Application Of Bupivacaine Plus Dexmedetomidine In Postoperative Patient-controlled Analgesia After Interscalene Brachial Plexus Block

Objective: We evaluated the effect of adding dexmedetomidine tobupivacaine for brachial plexus blockade. The primary endpoints were theonset and duration of sensory and motor block and duration of analgesia.Methods: Sixty patients scheduled for elective forearm and hand surgerywere divided into2equal groups in a randomized, double-blind fashion.Patients were assigned randomly to1of the2groups. In group B,40ml (200mg) of0.5%bupivacaine and1ml saline。In group BD,40ml (200mg) of0.5%bupivacaine and1mL dexmedetomidine were given. Motor and sensoryblock onset times, block durations, duration of analgesia and side effects wererecorded.Results: Demographic data and surgical characteristics were similar inboth groups. Sensory and motor block onset times were shorter in group BDthan in group B (P＜0.05). Sensory and motor blockade durations werelonger in group BD than in group B (P＜0.01). Duration of analgesia waslonger in group BD than in group B (P＜0.05). Systolic arterial bloodpressure levels in group BD at10,15,30,45,60,90, and120minutes weresignificantly lower than those in group B (P＜0.05). Diastolic arterial bloodpressure levels in group BD at60,90, and120minutes were significantly lowerthan those in group B (P＜0.05). In group BD bradycardia was observed in7patients, although there was no bradycardia in group B.Conclusion: Dexmedetomidine added to bupivacaine for axillary brachialplexus block shortens the onset time and prolongs the duration of the block and the duration of postoperative analgesia. However, dexmedetomidine also maylead to bradycardia.