Ultrasound-guided Selective Shoulder Block Versus Ultrasound-guided Interscalene Brachial Plexus Block, an RCT

This is a randomised, observer-blinded trial to compare selective shoulder block with interscalene block. Both blocks will be placed using an ultra-sound guided technique. Primary outcome measures will be postoperative pain scores and use of rescue opioids. Secondary outcome measures will be pre- and postoperative occurence of motor deficit of the arm and dyspnea, quality of sleep in the first night after surgery as measured by a numeric rating scale and overall satisfaction with pain therapy as measured by the International Pain Outcomes questionnaire and an NRS-score (0 = not satisfied at all and 10 = very satisfied). Primary and secondary outcome measures will be assessed during the first 24hours after surgery (assessment in the postanesthetic care unit (PACU) directly after admission and before discharge and in the surgical ward at 4, 8 and 24 hours after surgery). Overall satisfaction with pain therapy will be assessed 48hours after surgery. An interscalene block is a block of the plexus brachialis in the interscelene triangle (by injecting a local anesthetic around the nerve plexus). A selective shoulder block is a block of the suprascapular and axillary nerves (by injecting a local anesthetic around these nerves).