Shoulder anterior capsular (SHAC) block for analgesia in anterior shoulder dislocation: An emergency department case series.

BACKGROUND: Anterior shoulder dislocation is among the most common major joint dislocations presenting to the emergency department (ED) and is frequently managed with procedural sedation. Several analgesic and regional anesthesia strategies are available for shoulder reduction, each with distinct advantages and limitations. The Shoulder Anterior Capsular (SHAC) block is a superficial, ultrasound-guided interfascial plane technique that targets pericapsular nerve contributions to the glenohumeral joint via an anterior approach, offering a potentially motor-sparing and sedation-sparing alternative.

CASE PRESENTATION: We present two cases of ED anterior shoulder dislocation managed with the SHAC block at a high-volume Level 1 trauma center. In the first case, a 60-year-old male with recurrent dislocation underwent successful reduction without procedural sedation, reporting it as his least painful reduction among multiple prior experiences. In the second case, a 94-year-old female with a complex fracture-dislocation in cervical spine precautions received the SHAC block as an analgesic adjunct; although procedural sedation was ultimately required, the patient required no intravenous analgesia during a subsequent 36-h observation period. In both cases, the block was performed by an emergency medicine intern under supervision by a Pain Medicine fellowship-trained attending physician, preserving the ability to conduct post-reduction axillary nerve assessment.

CONCLUSION: The SHAC block was technically feasible in two selected patients with anterior shoulder dislocation and provided variable analgesia. Further study is needed to evaluate its efficacy, safety, positioning requirements, reproducibility, and appropriate patient selection.