Background Ultrasound-guided supraclavicular block (UGSCB) is an emerging technique gaining interest amongst emergency physicians that provides regional anaesthesia to the upper limb to tolerate painful procedures. It offers an alternative to the more traditional technique of a Bier block (BB). However, the effectiveness or safety of UGSCB when performed in the emergency department (ED) is unclear.

Methods SUPERB (SUPraclavicular block for Emergency Reduction versus Bier block) is a prospective open-label non-inferiority randomised controlled trial comparing the effectiveness of UGSCB versus BB for closed reduction of upper limb fractures and/or dislocations. Adult patients presenting with upper limb fracture and/or dislocation requiring closed reduction in ED were randomised to either UGSCB or BB. Once regional anaesthesia is obtained, closed reduction of the injured part was performed and immobilised. The primary outcome is maximal pain experienced during closed reduction measured via a visual analogue scale (VAS). Secondary outcomes include post-reduction pain, patient satisfaction, total opioid requirement in ED, ED length of stay, adverse events and regional anaesthesia failure.

Results Primary outcome analysis will be performed using both the intention-to-treat and per-protocol populations. The between-group difference in maximum pain intensity will be assessed using linear regression modelling with trial group allocation (UGSCB vs BB) included as a main affect. A pre-specified non-inferiority margin of 20 mm on the VAS scale will be used to establish non-inferiority of UGSCB compared to BB.

Conclusion SUPERB is the first randomised controlled trial to investigate the effectiveness and safety of UGSCB in the ED. The trial has the potential to demonstrate that UGSCB is an alternative safe and effective option for the management of upper extremity emergencies in the ED.