Ultrasound (US)-guided peripheral nerve block has increased in popularity. It has many advantages such as improved success rate, faster onset time, fewer needle passes, shorter performance time, and reduced procedural pain and vascular puncture. However, there is no information about postoperative analgesia.~Therefore, the investigators tested whether nerve stimulator (NS) - guided interscalene block was inferior to ultrasound-guided block in terms of duration of postoperative analgesia for shoulder surgery.
The investigators compared the postoperative analgesia of nerve stimulator-guided and ultrasound-guided interscalene block after shoulder surgery.